Shorter Contributions to General Geology 1952 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 Tfiz’y prqfessimal paper way printed as cflapters 14-117, inclusive UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON21953 GEOLOGICAL SCIENCES LIB: UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director @593 l; (a I V - 3’ *(‘li «iii-q. CONTENTS aroma mun [The letters in parentheses preceding the titles are those used to designate the papers for separate publication] Page (A) Ostracodes from the upper part of the Sundance formation of South Dakota, Wyoming, and southerntMontana, by Frederick M. Swain and James A. Peterson (published in December, 1952) ...................................... 1 (B) Tertiary stratigraphy of South Carolina, by C. Wythe Cooke and F. Stearns MacNeil (published in August, 1952) ...... 19 (C) Probable Reklaw age of a ferruginous conglomerate' in eastern Texas, by Lloyd William Stephenson (published in March, 1953) ................................................................................................... 31 (D) Cenomanian ammonite fauna from the Mosby sandstone of central Montana, by William A. Cobban (published in August, 1953) ........................................................................................... 45 (E) Mollusks from the Pepper shale member of the Woodbine formation, McLennan County, Texas, by Lloyd William- Stephenson (published' 1n May, 1953) ....................................................................... 57 (F) Conodonts of the Bar ‘ tt formation of Texas, by Wilbert H. Hass (published in August, 1953) ...................... 69 (G) Auditory region of Nort American fossil Felidae: Its significance in phylogeny, by Jean Hough (published in April, 1953) . . 95 (H) Cranial morphology of some Oligocene Artiodactyla, by Frank Whitmore (published in August, 1953) ................ 117 ILLUSTRATIONS PLATES 1, 2. Cytherellidae, Cypridae, and Cytheridae ....................................................... Following 18 3. Map showing areal distribution of Wilcox and lower part of Claiborne groups .......................... In pocket 4. Specimens and outcrops of ferruginous conglomerate, sand, and sandstone ............................. Facing 34 5. Outcrops of quartzitic sandstone and fossiliferous ferruginous sandstone ............................... Facing 35 6—9. Metoicoceras ................................................................................ Following 56 10—12. Dunveganoceras .............................................................................. Following 56 13. Molluscan fossils, mainly from the Pepper shale ................................................. Following 68 14—16. Barnett formation conodonts ................................................................. Following 94 FIGURE 1. Index map showing localities from which ostracodes were obtained ........................................ 2 2. Correlation of Tertiary formations of South Carolina ..................................................... 20 3. Whorl sections of Dunveganoceras ...................................................................... 53 4. Map showing localities at which conodonts of the Barnett formation were collected ........................... 75 5. Hoplophoneus primaevus oreodontis ............................................................ I; ........ 98 6, 7. Smilodon califomicus ........................................................................ ‘ ......... 101 8. Dinictis felina. ....................................................................................... 104 9. Dinictt’s cyclops ...................................................................................... 105 10. Viverricula indica rasse ............................................................................... 108 ll. Felts catus ........................... v ................................................................ 108 12. Curtis dingo ......................................................................................... 110 13. Vulpes velocc ......................................................................................... 111 14. Merycoidodon culbertsonii, lateral view .................................................................. 118 15. Merycoidodon culbertsonii, ventral view of basis cranii ..................................................... 119 7 16. M erycoidodon culbertsonii, internal View of basis cranii .................................................... 120 17. Merycoidodon culbertsom’i, ventral view of basis cranii with blood vessels restored ............................. 121 18. Frontal sections of skulls of M. culbertsonii and Dicoteles labiatus ........................................... 124 19, 20. Merycoidodon culbertosnii, thick sections of the skull ...................................................... 128 21, 22. Merycoidodon culbertsonii, thick sections of the skull ...................................................... 129 23. Merycoidodon culbertsonii, thick section of the skull ...................................................... 130 24. Merycoidodon culbertsom‘i, thick section of the skull, with nasal cavity and pneumatic sinuses outlined .......... 136 25. Poebrotherium wilsoni, lateral view of the skull ........................................................... 141 26. Poebrothe'rium wilson’i, ventral View of basis cranii ........................................................ 142 27. Poebrathem'um wilsoni, thick section of the skull .......................................................... 143 28. Poebrotherium wilsoni, thick section of skull ............................................................. 145 29. Leptomeryz evansi, lateral view of skull .................................................................. 148 30. Leptomeryx evansi, ventral view of basis cranii ........................................................... 149 31. Leptomerya: evansi, thick section ...... ’ .................................................................. 149 III M866441 Ostracodes from the. Upper part of the Sundance Formation of South Dakota,Wyorning and Southern Montana- 31/ . x: 0 GEOLOGICAL SURVENXJgROFESSIONAL PAPER 243-A‘2-44 GEOLOGECAL SCEENCES LIBRARY Ostracodes from the Upper part of the Sundanee Formation of South Dakota,Wyoming and Southern Montana By FREDERICK M. SWAIN and JAMES A. PETERSON SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 1—18 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-A1 Description and z'l/mtmz‘z’om of a Late jumm'cfauna from t/ze Redwater ska/e meméer, dz'strz'éutz'orz of ostra- codes in t/ze Swift formation UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1952 UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary GEOLOGICAL SURVEY V W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. — Price 35 cents CONTENTS Page Abstract ___________________________________________ 1 Description of species-Continued Introduction _______________________________________ 1 Cypridae ______________________________________ Stratigraphic sections ___________________________ >_ _ _ _ 2 Cytheridae _____________________________________ Ancestral relationships of the Redwater ostracodes ______ 7 References _________________________________________ Description of species- -- ______---_-.. ________________ 9 Index _____________________________________________ Cytherellidae ___________________________________ 9 ILLU STRATI ON S Plate 1. Cytherellidae, Cypridae, and Cytheridae ___________________________________________________ following index 2. Cytheridae ____________________________________________________________________________ folloWing index Figure 1. Index map showing localities from which the ostracodes described or listed in this paper were obtained ___________ III Page 10 14 17 Page 2 OSTRACODES FROM THE UPPER PART OF THE SUNDANCE FORMATION OF SOUTH DAKOTA, WYOMING, AND SOUTHERN MONTANA By FREDERICK M. SWAIN and JAMES A. PETERSON ABSTRACT The Redwater shale member of the Sundance formation or the upper part of the Sundance of Late Jurassic age in South Dakota, Wyoming and Montana has yielded 16 species of Ostra— coda representing: Paraparchites Ulrich and Bassler, Eridoconcha Ulrich and Bassler, Cytherella Jones, Macrocypris Brady, Aparchi— tocythere Swain and Peterson, n. gen., Monoceratina Roth, Camptocythere Triebel, Leptocythere Sars, Cytherura Sars, Pro- gonocythere Sylvester-Bradley, Protocythere Triebel, Cythereis Jones. These species are described and illustrated. Aparchitocythere n. gen., may have descended from Ellipsella Coryell and Rogatz of the Carboniferous and Permian or from a related genus, which in turn may have descended from Graph- iodactylus Roth of the Devonian and Mississippian. The Jurassic species of Monoceratina Roth, Leptocythere Sars, Cytherura Sars, and Camptocythere Triebel resemble Aparchi- tocythere in several features of the shell bilt M onoceratina at least seems to have originated in the Devonian from some genus other than Graphiodactylus. The Jurassic genus Progonocythere Syl- vester-Bradley may lie in the evolutionary stock that contains Savagella lindahli (Ulrich) of the Mississippian. Protocythere Triebel of the Jurassic and Cretaceous may have descended from some species of Basslerella Kellett of the Carboniferous and Permian. A new species here referred to Cythereis Jones may hear an ancestral relationship to Amphissites Girty or to a middle and late Paleozoic kirkbyid. INTRODUCTION This paper is the second dealing with marine Jurassic ostracodes from the western interior United States. The first article described species that occur in the Redwater shale member of the Sundance formation at the type locality (no. 1 on fig. 1) on Redwater Creek, south half, Sec. 2, T. 7 N., R. 1 E., Butte County, South Dakota (Swain and Peterson, 1951). The present article deals with ostracodes obtained by Imlay and Loeblich from the Redwater shale member of the Sundance formation at other localities in South Dakota, Wyoming and southern Montana, and also lists ostracodes from the stratigraphically equivalent Swift formation of central Montana. Imlay (1947, p. 231, 1949, p. 79) correlated the Redwater shale member, which is the upper part of the Sundancc, with the Ox— fordian stage of Europe. A more complete study of the stratigraphic distribution of the ostracodes of the Red- water in wells in the Powder River Basin, eastern Wyoming, is being conducted by J. A. Peterson. It is hoped later to describe the ostracodes collected by Imlay and Loeblich from the lower part of the Sun- dance formation of South Dakota, Wyoming and south- ern Montana and from the equivalent Rierdon forma- tion of central Montana. In addition, papers on the Foraminifera are being prepared by A. R. Loeblich, Jr., and Helen Tappan (Mrs. A. R. Loeblich) (1950a, 1950b). The Redwater shale member has yielded 16 species of Ostracoda, 14 of them new, representing 12 genera, one of which is new. Two genera are recorded for the first time in North America. The following species were obtained at the type locality of the Redwater shale member (Swain and Peterson, 1951): Paraparchites? sp., Eridoconcha monopleum Swain and Peterson, Aparchitocythere loeblichorum (Swain and Peterson), Progonocythere hieroglyphica, Swain and Peterson, P. crowcreelcensis Swain and Peterson, Oytherura lanceolata Swain and Peterson, Monocerattna sundancensis Swain and Peterson, Leptocythere imlayi Swain and Peterson, and Oytheridea? sp. The doubtful Pamparchites and the Eridoconcha, as representatives of the Leperditellidae (a family which almost completely died out at the end of the Paleozoic era), form the most primitive elements of the Red- water fauna. They have not been found in the collec- tions from other localities in the Redwater member or in the underlying portions of the Sundance. The Cytherellidae are represented in the Redwater by two species and the Cypridae by one species. The other ostracodes from the type locality are Cytheridae, mostly of primitive character With the terminal hinge- teeth and sockets weak or crenulate. The following species were not found in the type locality of the Redwater shale member and are de— scribed here: C’ytherella paramuensteri, 0. ventropleum, Alecrocypris minutus, Aparchitocythere typica, Oythereis? zygoventralis, Protocythcrc quarlricarinata, and Camp— tocythere elliptica. ' 2 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952. \\ 6 \ X _—_._ I ———_._-_z...____-_____ i ‘ I 2 °sn 'd en 0” . \ X50C d Sundonce lxl speorflsh D A K o T A l I ° Y o |°x s O U T H 0 I I PIERRE I W Y 0 M . I N G o . . 3x, Ropld City 0| LIST OF LOCALITIES Newcastle | K I. Redwuter shale, s I/2 sec. 2,1’. 7 N.,R.lE.,Butte L County, Shook. 5 j 2. Redwoter shale sec. 22 T 58 N. R.89 W . , . - . -- I _——_——--—-\ ' Sherldun County, wyo. I__.._._...————_.——--— ~ g \ \ 3. Redwuter shale, sec. IS,T.45 N.,R.60 w., oCasper \f— ‘ \ Weston County, Wyo. ‘ 4. Redwoter shale, sec.3,T.6N., R.2E., K Lawrence County. S. Oak. 5. Redwater shale , N l/Z sec. l4,T.7S., R.3 E., I Fall River county, 5. Dok. I t 6. Swlft formation,sec. l9, T.7$., R.24 E., Carbon County, Mont. 7. Swift formation, sec. 2,T.l4 N., R.|9E.,cnd S K A see. 35.,T.I5N., R.19 E., Fergus County, Mont. | B R A 8.5M" tormation,sec.'l7,T.l4N.,R.20E., | N E Fergus County, Mont. 9, Swift tormation,sec.32 125 N., R.24 E., Phillips County, Mont. ' CHEYENNE l0. Switt formation sec. 36, T. 53N., R. IOZ W., 0 . _— Park County, w‘yo. __ — __ — __ "-" _ 1 LINCOL‘EI 25 0 200 Miles I l I FIGURE L—Index map showing localities from which the ostracodes described or listed were obtained. In the present material, ostracodes were most abun— dant in Red Gulch, Sheridan County, Wyoming. Descriptions of this and the other measured sections of the Redwater shale member from which ostracodes were obtained follow. Index numbers assigned to beds that were sampled (J—61p, etc.) indicate the occurrence of each species in the Descriptions of Species. STRATIGRAPHIC SECTIONS The following sections were measured and described by R. W. Imlay in 1945, and samples were collected for microfossils by R. W. Imlay and A. R. Loeblich in 1948: Jurassic formations along east side of Red Gulch about 2% miles south of Little Horn River in Sec. 22, T. 58 N ., R. 89 W., Sheridan County, Wyoming. (Measured by R. W. Imlay and Wm. Saalfrank 1945.) Collected September 23, 1948 by R. W. Imlay and A. R. Loeblich, Jr. (Locality 2 on fig. 1.) Kootenai formation (basal part): Sandstone, fine-grained, grayish-white _____________ Concealed _____________________________________ Sandstone, massive, cliff-forming, light-gray, strongly cross-bedded, irregular lower surface ____________ 'Morrison formation: 64. Shale, soft, light-red, upper 3 feet mostly green- ish-gray __________________________________ Sandstone, hard, light-gray, weathers yellowish- Shale and some sandstone, yellowish-gray ______ Shale, soft, yellowish-gray ____________________ Sandstone, hard, grayish-white, weathers dark gray, forms ledge __________________________ Shale, soft, light greenish-gray ________________ Sandstone, hard, grayish-White, weathers dark gray, forms ledge __________________________ Shale, partly silty, light-red and greenish-gray- _ - Limestone, shaly, hard _______________________ Shale, light-red, becoming yellowish at top _____ Sandstone, fairly hard, light-gray ______________ 63. 62. 61. 60. 59. 58. 57. 56. 55. 54. Feet 15 20 to Kit-‘Hznts 1K OSTRACODES FROM THE UPPER PART OF THE SUNDANCE FORMATION ' 3 Morrison formation—Continued 53. Shale, yellow to gray, silty, several thin layers of . fine—grained gray sandstone near top _________ 52. Shale, ribboned dark- and light-gray, silty ______ Feet 3% 8 Total thickness of the Morrison formation 102% Sundance formation: Part of the Redwater shale member: 51. Sandstone, light-yellow, soft, cross-bedded, forms cliff locally, upper part massive, lower part . thin- to medium-bedded ____________________ 2:5 50. Shale, sandy, thinly ribboned with gray shale, . light-yellow, soft--____-________________'___ 5 49. Sandstone, hard, light-yellow, cross-bedded _____ 1 48. Sandstone and shale, thinly bedded, soft _______ 1 47. Sandstone, massive, very soft, dark-yellow, some glauconite ________________________________ 2 46. Sandstone, hard, light yellowish-gray ________ % to 1% 45. Sandstone, massive, very soft, dark-yellow, some glauconite ________________________________ 7 44. Shale, sandy, yellowish-gray, soft, mostly cov- ered _____________________________________ 25 43. Sandstone, shaly, yellow _____________________ 3 42. Shale, sandy, dark yellowish-gray _____________ 20 41. Limestone, silty, nodular _____________________ % 40. Shale, sandy, medium-gray ___________________ 7 39. Shale, calcareous, medium-gray, abundant belemnites and G’ryphaea nebrascensis ________ 138 Total thickness of the Redwater shale member ____________________________ 233 Channel samples of Redwater shale Hem, above member. base (feet) J —61p _________________________ 145—152 0 _________________________ 137—145 ~ 11 _________________________ 130—137 m-______-_______; _________ 122-130 1 __________________________ 117—122 k _________________________ 112—117 j __________________________ 107—112 i __________________________ 102-107 h _________________________ 97—102 g _________________________ 92— 97 f __________________________ 86— 92 e _________________________ 80— 86, d _________________________ 68- 80 c __________________________ 58- 68 b _________________________ 48— 58 a _________________________ 11— 21 Hulett sandstone member: 38. Oolite, fine, sandy, light-brown, weathers yellow- ish brown, traces of fossils __________________ 6 37. Sandstone, massive, hard, forms top of cliff, light yellowish-gray, fine-grained, cross-bedded, weathers light gray ________________________ 10 36. Oolite, coarse, yellowish-gray, weathers light gray, upper 6 inches soft and fossiliferous- _ _ . 1% 35. Sandstone, chunky, grayish-white, weathers whitish __________________________________ 3 34. Sandstone, calcareous, massive, light yellowish- gray, weathers buff, fine grained ____________ 7 33. Oolite, silty, gray ___________________________ 1 Total thickness of Hulett sandstone member ____________________________ 28% Sundance formation—Continued Feet Stockade Beaver shale member: 32. Shale, soft, brownish-gray, papery, fine, sandy, forms base of cliff _________________________ 5 31. Shale, soft, brownish-gray, papery fine, sandy--- 15 30. Shale, soft, calcareous, medium-gray, abundant Gryphaea nebrascensis, some belemnites ______ 76 29. Shale, calcareous, gray, contains several beds of slightly oolitic gray limestone, fossiliferous _____ 5% 28. Shale, calcareous, gray. Sample J—60a from beds 28 and 29 ________________________________ 1% Total thickness of Stockade Beaver shale- - 103 Channel samples of Redwater shale member: Height above base (feet) J—60m ___________________________ 68—76 1 _____________________________ 60—68 k ___________________________ 52—57 j _____________________________ 47—52 i ____________________________ 42—47 h- _> _________________________ 37—42 g ___________________________ 32—37 f ____________________________ 27—32 e ___________________________ 22—27 (1 ___________________________ 17—22 c ___________________________ 12—17 b ___________________________ 7—12 Gypsum Spring formation: 27. Shale, maroon, soft __________________________ 41 26. Shale, light greenish-gray _____________________ 25. Limestone, silty, white, soft, some thin beds of yellowish chert, upper foot weathers yellow, remainder weathers white ___________________ 6 24. Shale, soft, light-red, some white layers in lower half, become light pink toward top, uppermost foot purplish ______________________________ 23 23. Clay-shale, soft, white _______________________ 6 22. Limestone, shaly, greenish-gray _______________ % to 2 21. Shale, fairly soft, mostly purplish-pink; many layers are greenish-gray ____________________ 4 20. Limestone, shaly at base and top, hard and ledge- forming in middle; mainly light gray with some fiinkish layers, grades into underlying unit, fragmentary pelecypods at top ______________ 3% 19. Shale, soft, mostly maroon, some greenish-gray - 13 18. Shale, soft, greenish-gray, some pink ____________ 12 17. Limestone, dolomitic, hard, dense, light-gray, leached __________________________________ % 16. Shale, light-red to greenish-gray, soft- _ _ - _; _____ % 15. Limestone, dolomitic, hard, dense, light-gray--__ 1 14. Limestone, oolitic, light-yellow ________________ % 13. Shale, soft, light-red _________________________ % 12. Limestone, dolomitic, hard, dense, light—gray-__- 1% 11. Shale, chunky, soft, pink to yellow, partly silty- 2% 10. Limestone, thin-bedded, white, dense __________ 1 9. Shale, soft, pink to light-green ________________ % 8. Limestone, light yellowish-gray, dense, hard, laminated ________________________________ 1 7. Shale, soft, pink to gray, one 3-inch layer of dense white limestone 1n middle __________________ 5 6. Limestone, dense, hard, nearly white __________ 1 to 1% 5. Shale, deep- red, soft, spotted with gray ________ 1 4. Shale, light greenish-gray, soft, some layers nodular __________________________________ 5 4 ~1 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 Gypsum Spring formation—Continued Feet 3. Shale, partly silty, maroon, traces of greenish shale ____________________________________ 10 2. Siltstone and silty shale, maroon, some spots of light green throughout _____________________ 40 1. Siltstone, maroon, weathers pinkish, rests on leached to slightly cavernous maroon siltstone of Chugwater formation ____________________ 8 Total thickness of Gypsum Spring forma- tion _______________________________ 195% Chugwater formation The Red Gulch locality yielded most of the ostracodes described herein. A table showing distribution of the species in the Redwater shale member of the Sundance formation at Red Gulch faces p. 6. Gypsum Spring and Sundance formations on west side of Stockade Beaver Creek, 5 miles NE of Newcastle in Sec. 18, T. 45 N., R. 60 W., Weston County, Wyoming. (Locality 3 on fig. 1.) Collected Sept. 21, 1948 by R. W. Imlay and A. R. Loeblich, Jr. Sundance formation (part): Redwater shale member (part): 12. Shale, gray and greenish-gray; some layers are silty to sandy; contains many belemnites and some selenite; top not exposed. 11. Sandstone, yellowish-gray, very soft, fine-grained- 5 10. Shale, gray, partly silty, soft _________________ 18 9. Sandstone, white; weathers light gray, fairly soft, thick to thin—bedded, glauconitic; includes some thin beds of gray shale and shaly sand- stone ____________________________________ 7 Channel samples of Redwater shale member: Height above Feet base (feet) J—52f ____________________________ 81—88 e ___________________________ 74—81 (1 ___________________________ 33—41 c ___________________________ 28—33 b ___________________________ 7—25 Lak member: 8. Siltstone and sandstone, mostly maroon; 3. 2-8>0t bed of greenish gray siltstone 15 feet below top in a sharp contact with overlying glauco- nitic sandstone ____________________________ 80 Iulett sandstone member: 7. Sandstone, white, massive, soft, very fine grained; grades upward into siltstone and then into a foot of soft green shale at top _______________ 6 6. Siltstone, shale and some fine-grained sandstone, greenish gray to yellowish gray, weathering pink to buff ______________________________ 9 5. Sandstone, thick—bedded; forms sheer clifi‘; ripple-marked, light grayish yellow, weather- ing buff, glauconitic _______________________ 30 4. Shale, sandy, interbedded with‘ shaly to thin- bedded sandstone; shale is greenish gray; sand— stone is yellow; grades into adjoining units; forms recess in cliffs; contains Comptonectes"- 12 3. Sandstone, medium- to thick-bedded with some shaly partings, ripple-marked, light grayish yellow, weathering bufl, glauconitic; grades into underlying unit _______________________ 12 Sundance formation—Continued Feet Stockade Beaver shale member: 2. Shale. dark gray, soft, fissile; contains some nodules of limestone in lower 10 feet and some limonitic shaly sandstone in lower foot; selenite crystals and Camptonecb’es present ____________ 63 Channel samples of Stockade Beaver shale member: Height above bare (feet) J—51j ____________________________ 55—63 i______-_; ___________________ 50—55 h ___________________________ 45—50 g ___________________________ 39—45 f ____________________________ 34—39 e ___________________________ 27—34 d ___________________________ 22—27 0 ___________________________ 16—22 b ___________________________ 8—16 9. ___________________________ 0—8 Gypsum Spring formation: 1. Gypsum, white, granular, bedded; forms low cliff; rests sharply on the slightly irregular surface of the red beds of the Spearfish forma- tion _____________________________________ 8—12 Spearfish formation: Sundance and Gypsum Spring formations one mile north- northeast of center of Spearfish in Sec. 3, T. 6 N., R. 2 E., Lawrence County, South Dakota. Collected September 21, 1948 by R. W. Imlay and A. R. Loeblich, Jr. (Locality 4 on fig. 1.) Morrison formation: Mostly covered. Basal beds consist of fine—grained, pseudo— oolitic, yellow sandstone. Sundance formation: Redwater shale member: Feet 18. Shale, dark-gray fissile; contains some very thin beds of fine-grained, greenish-gray sandstone- 15 17. Limestone, shaly, and sandy shale, fossiliferous- 8 16. Shale, dark-gray; some silty beds in lower 25 feet; belemnites abundant _______________________ 65 15. Sandstone, yellow, soft _______________________ 2 14. Shale, dark-gray ____________________________ 11 13. Sandstone, yellow, soft _______________________ 2 12. Shale, greenish-gray, silty ____________________ 7 11. Sandstone, gray, soft, glauconitic ______________ }4 Channel samples of Redwater shale member: _. Height above base (feet) J—47h __________________________ 95—106 g __________________________ 85—95 f ___________________________ 77—85 e ___________________________ 69—77 d __________________________ 59—69 c __________________________ 49—59 h __________________________ 21 a __________________________ 1—8 Lak member: 10. Sandstone, fine-grained, and siltstone, mostly maroon; some greenish layers and spots; weathers light pink ________________________ 60 Hulett sandstone member: 9. Sandstone and silty shale, soft, yellowish-gray__ 17+ 8. Shale, silty, greenish gray ____________________ 6 7. Sandstone, fine-grained, mostly yellow, some pinkish __________________________________ 4 OSTRA-CODES FROM THE UPPER PART OF THE SUNDANCE FORMATION 5 Sundance formation—Continued Feet Hulett sandstone member—Continued 6. Shale, silty, and siltstone, light red and yellow— ish, weathering pinkish _____________________ 11 5. Shale, sandy, greenish gray to pinkish; some pink shaly sandstone ______________________ l2 4. Sandstone, thick- to medium-bedded, mostly pink to yellow, fine-grained, ripple-marked, glauconitic _______________________________ 6 3. Shale, greenish-gray, partly sandy, poorly ex- posed ____________________________________ , l2 2. Sandstone, thick- to medium—bedded, mostly pink to yellow, fine-grained, ripple-marked, glauconitic _______________________________ 29 Stockade Beaver shale member: 1. Shale, soft, brownish gray in lower 15 feet, dark gray above; weathers yellowish gray; a few pitted pebbles of a very dense metamorphic rock in basal foot _________________________ 60 Channel samples of Stockade Beaver shale member: Height above base (feet) J~46h ____________________________ 55—60 g ___________________________ 45—53 f ____________________________ 38—45 e ____________________________ 30—38 d ___________________________ 23—30 c ___________________________ 14—23 b ___________________________ 6—14 3. ___________________________ 0—6 Samples from Stockade Beaver member are channel samples. Gypsum Spring formation (part): Gypsum, bedded, white, sugary ___________________ 1 Shale, yellowish-gray, soft. Sample J—45 __________ 2 Sundance formation about three miles west-northwest of Minnekahta in the N% Sec. 14, T. 7 S., R. 3 E., Fall River lounty, South Dakota. Collected September 22, 1948 by R. W. Imlay and A. R. Loeblich, Jr. (Locality 5 on fig. 1.) Sundance formation: Redwater shale member: Feet 15. Shale, dark-gray, soft, fissile; upper part has many ledges of limestone from a few inches to 2 feet thick, belemnites common near base. Overlain, apparently along a fault contact, by about 15 feet of fossiliferous gray limestone that grades up into hard fine-grained white sandstone that is overlain by shale typical of the Morrison formation. Estimated thick- ness of the shale __________________________ 80 , l4. Sandstone, shaly, light gray, glauconitic, ripple- marked, poorly exposed ____________________ 18 13. Sandstone, greenish gray, soft, glauconitic ______ 9 Incomplete thickness of Redwater shale member ____________________________ Channel samples of Redwater shale member: 107 Height above base (feet) J—56c ____________________________ 18—23 d ___________________________ 23—30 b ___________________________ 13% a ___________________________ 9 993981—52—2 Sundance formation—Continued Feet” Lak member: 12. Shale, maroon, soft __________________________ 18 11. Sandstone, maroon, massive __________________ 4 10. Shale, grayish-green _________________________ 5 9. Siltstone and shale, maroon ___________________ 6 8. Sandstone, salmon-pink, massive ______________ 12 7. Siltstone and shale, maroon ___________________ 15 Total thickness of Lak member __________ 60 Hulett sandstone member: 6. Shale, medium gray to greenish gray--____ _ - , - _ 10 5. Sandstone, nearly white, medium-bedded at base, shaly in middle, and thin-bedded at. top, medium- to fine-grained, ripple-marked, weathers light gray ________________________ 22 Total thickness of Hulett sandstone mem- ber ________________________________ 32 Sample J—55 is from zone 6, 22 to 32 feet above base of Hulett sandstone member. Stockade Beaver shale member: 4. Shale, dark gray, some limonitic nodules and very thin layers of calcareous sandstone in lower 5 feet. Lower foot characterized by fossiliferous limonitic nodules and by subangular pebbles from )4 to )6 inch in diameter of a very hard, dense metamorphic rock. U.S.G.S. Mes. Loc. 19558 from basal 5-foot zone contains Eumi- crotis curta (Hall), Corbicellopsis? inomata, (Meek and Hayden), Quenstedtia sublevis (Meek and Hayden), and Astarte? fragilis Meek and Hayden. U.S.G.S. Mes. Loc. 19559 collected from the entire unit contains Penta- cm‘nus asteriscus Meek and Hayden, Eumz'crotis orbiculata (Whitfield), E. curta (Hall), Campton- nectes extenuatus (Meek and Hayden), Pleura- mya subellt’ptica (Meek and Hayden), Corbi- cellopsis? inornata (Meek and Hayden), Ostrea sp., and Pachyteuthis sp ____________________ 48 Channel samples of Stock- Height above ade Beaver shale member: - base (feet) J—54g ____________________________ 35—41 f ____________________________ 31—35 e__________________-___,_____ 25—31 (1 ___________________________ 17—25 c ____________________________ 11—17 b ___________________________ 6—11 a ____________________________ 0— 6 Gypsum Spring formation: 3. Sandstone, white, medium-bedded, medium- grained, grades into underlying beds ________ 2%, 2. Sandstone, red to salmon-pink, massive, cliff- forming but fairly soft, coarsely cross-bedded, moderate- to fine-grained, some fine chert grit throughout, weathers brick red; 1 foot of white sandstone about 2 feet below top ____________ 42 1. Sandstone in two massive beds; lower bed pink to yellow; upper bed yellow; rather soft, con- tains chert grit and some pebbles as much as )5 inch in diameter _________________________ 3 Total thickness of Gypsum Spring for- mation _____________________________ 47% SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 Distribution of Ostracoda in the Redwater shale member of the Sundance formation, Red Gulch section, Sheridan County, Wyo. [Locality 2 on fig. 1, samples l—61a—p.] f g h i j k l m Cytherella paramuen- stert, n. sp. Oytberella oentropleu- to, n. sp. Macrocypris minutus, n. sp. Aparcbltocyth ere typ- ica, :1. gen., n. sp. Aparcbitoc hereloeblt- - chorum ( wain and Peterson). Monocemtina sandan- censts Swain and Peterson. Camptocvthere ellip- tlca, n. sp. Leptocythere imtayl Swain and Peterson. 011th erurai lanceolata Swain and Peterson. Proaonocythere hiero- alyphica Swain and Peterson. Proaonocuth ere crow- creekensis Swain and Peterson. Proton/there quadrice- rinata, n. sp. Cythereis! zyaooentra- Its, n. so. Number of valves (complete shells). Adult male valves ..... Adult female valves... Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female vales. . Immature valves ______ Number of valves (complete shells). Adult male valves ..... Adult female valves. Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female valves. Immature valves ...... Number of valves (complete shells). Adult male valves.. Adult female valves (complete shells). Adult male valves ..... Adult female valves. Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female valves. Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female valves. Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female valves. Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female valves Immature valves ...... Number of valves (complete shells). Adult male valves Adult female valv Immature valves.. Number of valve (complete shells). Immature valves ...... Number of valves (complete shells). Adult male valves ..... Adult female valves Immature valves ...... 1 74 (8) 186(5) 369(116) 135(29) 243(36) 15(7) 116(57) 94 (38) 28(12) 176(53) 156 (69) 14 106 152 2 26 18 4 24 16 . I The "number of valves" includes in each instance both single valves and whole specimens; the numbers in parenthesesare of complete shells. Numbers of male and female valves are given where dimorphism is recognized, but in Comptocythere mature specimens. For example, Cytherella paramuenstert is represented at 10 collatiptica the figures are tentative because of difficulty in distinguishing male dimorphs from im- ity J ~61f by 74 valves of which 16 are 8 complete shells and the remaining 58 are separated valves. Forty of the total of 74 valves are interpreted as adult males, 8 are adult females and 26 are immature valves. Samples from Swift formation of Montana Area and sample Height (in feet) above base of formation Southwest corner of Red Dome, east of Bridger, in Pryor Mountains, Sec. 19, T. 7 S., R. 24 E., Carbon County, Mont. 10c ................................. 15 11a _________________________________ 20-23 11b ................................. 26 11c ____________________________ ' _____ 29-33 11d ................................. 40 12a ________________________________ 40—45% 12b ________________________________ 45%-—51 (Locality 6 on fig. 1.) Sample: J—lOa ................................ At base 10b- - __ Upper part of 7-ft basal sandstone bed Samples from Swift formation of Montana—Continued Height (tn feet) above base of Area and sample formation Along east side of road, % to 1 mi north of gypsum factory in Sec. 2, T. 14 N., R. 19 E., and Sec. 35, T. 15 N., R. 19 E., near Heath, Fergus County, Mont. (Locality 7 on fig. 1.) Sample J—14a __________________________________ One mi southwest of Piper on the northwest corner of the escarpment due east of Bacon Ranch, Sec. 17, T. 14 N., R. 20 E., Fergus County, Mont. (Locality 8 on fig. 1.) Sample J—19 ______________________________ Basal layers One mi southwest of Landusky, Sec. 32, T. 25 N., R. 24 E., Little Rocky Mountains, Phillips County, Mont. (Lo- cality 9 on fig. 5.) 6—11 OSTRACODES FROM THE UPPER PART OF THE SUNDANCE FORMATION Sample from Swift formation of Montana-Continued . Sample from Swift formation of Montana—Continued Height (in feet) Height (in feet) above base of above base of Area and sample ’ormatlon Area and sample formation One mi southwest of Landusky—-—Continued One mi southwest of Landusky——-Continued Sample: J—22a ________________________________ 1 Sample: J—22j __________________________________ 37 22b __________________________________ 4 221 __________________________________ 50 22c _________________________________ 9 Gorge of Shoshone River, 2 mi west of Cody, Wyoming. 22d __________________________________ 13 (Locality 10 on fig. 1.) 22f __________________________________ 22 Sample: J—43b _________________________________ 5~10 22g-_’_____________________-_-__-_7__ 25 43c _________________________________ 10—15 22h ________________________________ 29 Distribution of ostracodes in the Swift formation of Montana [R=1—5, LC=6-15, C=16—25, A=26—50, and VA=more than 50 specimens] J —10 J—11 1—12 J—14 J—19 1-22 J—43 Cytherellot‘dca sp __________ Cytherclloidea‘? sp ......... 011th erella paramuensteri- . Macrocypris mini/Juan" Aparchitocythere typica.... _ _ , A. cf. A. loeblichorum..._ _ Monoceratim sundancensis _ Leptocyth ere imlaui ....... . Cyth ernra? lanceolata. .. _ . 0.? sp .................... Progonocythere hieroglyph- tea. P. crowcreekemia ......... P.? 51) .................... Protocythere guadrtcartnata Bythocypris? sp ........... _ new genus resembling Theriosunoecum. . new genus resembling Orthonotacuthen ......... new genus resembling forms In Rlerdon tm..__ ANCESTRAL RELATIONSHIPS OF THE REDWATER OSTRACODES The late Paleozoic and the described Mesozoic ostra- codes are, for the most part, very different, Perhaps the keys to their interrelationships lie in the almost entirely unknown Triassic faunas. Among the very few genera of Permian ostracodes that also occur in Jurassic rocks are Paraparchites Ulrich and Bassler, Eridoconcha Ulrich and Bassler, Bairdia McCoy, Cytherella Jones, Bythocypris Brady, Macrocypris Brady, Pontocypris Sars, and MonoceratinaRoth. The Per- mian genus Tomiella Spizharsky is very close to, if not the same as, Limnocythere Brady of the Cenozoic. Doubt can be raised in practically all of these instances as to the equivalence of the Paleozoic genera and those in younger rocks, particularly because of the generally simpler muscle-scar patterns of the Paleozoic species. If they are not congeneric however, the Paleozoic species and those of the Mesozoic and Gen- ozoic are strikingly homeomorphic. Until the Triassic ostracodes are better known and the details of shell structure in the late Paleozoic ostracodes have been more thoroughly studied, comparisons between many late Paleozoic and Mesozoic ostracodes will remain largely subjective. The following tentative suggestions concerning the relationships of several groups of ostra- codes are based on Swain’s studies of various ostracode faunas, and examination of type specimens in the United States National Museum. The Cytherellidae of the Mesozoic do not differ in principal shell features from those of the Permian. The distinction between Cavellina Coryell (emended Kellett, 1935, p. 144) in which the posterior inner transverse ridge of the females is long, and Oytherella Jones in which this ridge is shorter, is very obscure. Oytherella paramuensteri, n. sp. of the Upper Jurassic has the posterior ridge and corresponding external transverse depression extending from the dorsal to the ventral margin, and if the species had been found in the Paleozoic would very likely have been referred to Cavellina. Swain feels that there is little value in re- taining anellina and recommends that it be discarded or reduced to the status of a subgenus. The Bairdiidae also seem to continue with relatively little change from the Permian into the Mesozoic. The hinge structures of the Mesozoic Bairdia are poorly known, and many of the species may eventually be 8 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 referred to Bairdoppillata Coryell, Sample and Jennings, in which denticulations occur on the selvage along the dorsal slopes. Marine Cypridae,such as Paracypris Sars, are present both in Paleozoic and in younger rocks and, although the muscle scars of the Paleozoic species are simpler than those in the Mesozoic and Cenozoic species (Scott, 1944, p. 163), there is little to distinguish them generically. The marine Cypridae are not important elements in most fossil ostracode faunas. The roots of the Cytheridae, which dominate post- Paleozoic marine ostracode faunas, are obscure, but it seems very possible that the family is polyphyletic. Kellett (1935, p. 155) concluded that the Pennsylvanian and Permian Basslerella Kellett is the direct ancestor of Cytheridea because of the general shape, weakly crenulate hinge, and calcified inner lamellae of the former. Swain examined types of species of Basslerella, and observed these features in B. crassa Kellett (the type of the genus), but feels that the other species are less certainly representative of the Cytheridae and perhaps are closer to the Cypridae. Ellipsella, distenta Kellett (1933, p. 82, pl. 13, figs. 18—20) from the Pennsylvanian Howard limestone of Kansas is much like Aparchitocythere Swain and Peter— son, n. gen., in outline, nearly straight hinge margin, and in the slight but clear differentiation along the hinge of the left valve to form weak terminal teeth (rather than left valve sockets in Aparchitocythere), an interterminal weak, perhaps slightly crenulate bar and a weak groove dorsal to the bar. The writers would orient the species so that the more truncated, higher end is posterior, making the right valve the larger and placing the weak sulcus anterior to midlength. Other specimens figured by Kellett from the lower Permian (1933, pl. 13, figs. 14—16) may represent a different species. Ellipsella (Coryell and Rogatz, 1932) is placed in the Kloedenellidae by Kellett who states however that, “* * * it might well belong in the Glyptopleuridae, the hingement apparently being similar to that of the latter genus [family]” (Kellett, 1933, p. 82). The present writers offer another sug- gestion: that its outline and submedian pit or weak sulcus ally Ellipsella with Graphiodactylus Roth for which Kellett (1936, p. 772) proposed the family Graphiodactylidae. We suggest that Aparchitocythere, - n. gen., representing one section of Jurassic Cytheridae, is related to Ellipsella Coryell and Rogatz of the Penn- sylvanian and Permian, which in turn may be de- scended from Graphiodactylus Roth of the Devonian and Mississippian. ' The holotype of Kirkbye lindahli Ulrich from the Warsaw limestone, Mississippian, at Columbia, Illinois, is the genoholotype of Savagella. Geis (1932, p. 168) of the family Kirkbyidae. The specimen, here called a left valve, is subquadrate with an abraded but straight, apparently simple hinge; the anterior cardinal angle is much more obtuse than the posterior; the external surface has an anteromedian node and postjacent furrow, a "well-developed marginal rim, and coarse surface reticulations. The valve interior is filled with matrix. This species or a related form may lie in the ancestral stock of the Jurassic genus Progonocythere Sylvester-Bradley'which is represented in the Red- water fauna by P. hieroglyphica, Swain and Peterson and P. crowcreekensis Swain and Peterson. The hinge of Progonocythere is more advanced in that it bears terminal crenulate elements. Protocythere Triebel, which is represented by several species in the Cretaceous, and now has been found in the Redwater shale member of the Sundance formation, may be descended from Basslerella Kellett. As stated above Basslerella, is believed by Kellett to be ancestral to the cytherideids of the Mesozoic. Protocythere closely resembles Haplocytheridea Stephenson and other typical cytherideids in hingement and general form, but differs in its longitudinal pattern of ridges and more compressed posterior end. The ancestral relationships of the Redwater species of Monocemtina Roth, Leptocythere Sars, Oytherura Sars, Oamptocythere Triebel, and Uythereis Jones are obscure. The Redwater species of the first four genera have in common weak ventral alae or swellings, and all five genera resemble Aparchitocythere, n. gen, whose left valve is the larger, but whose right valve extends beyond the left along the hinge and the hinge bears only weak simple terminal teeth and sockets. Whether these similarities are phyletic or merely homeomorphic only additional study of material from older deposits will reveal. Monocemtina is found in rocks as old as hfiddle Devonian. It is not clear whether the Mesozoic and Cenozoic ”Monocemtina” are congenerie with those of the Paleozoic. Swartz (1936, p. 554) placed the genus in the Acronotellidae, but post-Paleozoic species are generally placed in the Cytheridae. The ancestry of Cythereis is also obscure. The fe- males of 0.? zygoventralis, n. sp. are very similar in general shape, marginal rim and strong longitudinal ridges in the ventral half, to some species of Amphis- sites Girty of the middle and late Paleozoic. The hinge of Cythereis, consisting of an anterior socket and tooth, interterminal bar or groove and posterior socket or tooth, is the most advanced type of ostracode hinge. Indirect support of a possible relationship of the genus to Amphissites is that the hinge of the‘latter is relatively much more advanced than that of other Paleozoic ostracodes, and typically bears terminal sockets and teeth (Kellett, 1933, p. 93). The present writers OSTRACODES FROM THE UPPER PART OF THE SUNDANCE- FORMATION 9 would reverse the orientation of Amphissites used by Kellett and refer to the more broadly rounded end as anterior. The writers believe that there may be an ancestral relationship between Amphissites and 0y- thereis? zygcventmlis but, as explained in the description of the species, it is not clear Whether 0.? zygoventmlis represents Cythereis or a new genus. DESCRIPTION OF SPECIES Order OSTRACODA Latreille, 1802 Suborder PLATYCOPA Sars, 1866 Family CYTBERELLIDAE Sars, 1866 Genus CYTHERELLA Jones, 1849 Cytherella paramuensteri Swain and Peterson, n. sp. Plate 1, figures 1—7 Shell subquadrate in lateral View; dorsal margin nearly straight, about two-thirds of shell length; ven- tral margin slightly concave medially, subparallel to dorsum; terminal margins broadly rounded, posterior truncate below midheight. Right valve larger than left, overlapping and extending beyond the other around entire periphery, most strongly along dorsum and ventrum. Valves compressed, but with female dimorphs inflated in posterior fifth. Surface very slightly depressed in mid—dorsal region; a small pit, the external expression of the muscle scar, lies just dorsal to midheight; general surface smooth except for very minute, closely spaced pits on marginal portions of valves. Margin of right valve grooved for reception of edge of left; along hinge, groove slightly deeper than else— where, and posteriorly very shallow. Muscle scar a small, slightly dorsomedian elevation, consisting of four or five longitudinally elongated spots. Inner lamellae and pore canals lacking. Length of holotype (U.S.N.M. 117957), a female shell, 0.83 mm, height 0.45 mm, thickness 0.32 mm. Length of a male paratype (U.S.N.M. 117958, pl. 1, fig. 2) 0.72 mm, height 0.30 mm, thickness 0.26 mm. Relationships.~This species closely resembles 0. muensteri (Roemer) of the Cretaceous in the tiny sur— face pits of the females, but is more subquadrate. It is also closely similar to other species of Oytherella that occur in the Lower Cretaceous and Upper Jurassic of the Gulf of Mexico region (Alexander, 1929, pp. 47—49; Swain, 1949, pl. 3), particularly 0. scotti Alexander and O. comanchensis Alexander, but dimorphism in these species has not been well demonstrated. Adult speci— mens apparently are far outnumbered by immature molts in the present collections. Among the adults the smaller, less convex, males are more numerous than the females. 993981—52—3 Occurrence—(1) Upper part of the Sundance or Red— water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; localities J—61e—n. (2) Swift formation, Red Dome, Sec. 19, T. 7 S., R. 24 E., Carbon County, Montana; J—11a—d, J—12b. (3) Swift formation, near Heath, Sec. 2, T. 14 N., R. 19 E. and Sec. 35, T. 15 N., R. 19 E., Fergus County, Montana; J—14a. (4) Swift formation, Shoshone River Gorge, 2 miles west of Cody, Wyoming; J—43b. (5) Specimens probably representing this species also occur in the lower part of the Sundance formation in Wyoming. Cytherella ventropleura Swain and Peterson, n. sp. Plate 1, figures 10—12 Shell minute, ovate in lateral View; highest near anterior end; dorsal and ventral margins slightly con- vex, ventrum straightened medially; anterior margin broadly rounded, posterior margin narrower and slightly extended medially. Right valveplarger than left, ex- tending beyond the other most noticeably along ventrum. Valves compressed except for postventral broad longitudinal swelling on surface of each valve; general surface very finely pitted. Hingement consists of simple groove in right valve for reception of edge of left. Muscle scar not clearly seen but seems to consist of a large circular spot situated near anterior end of postventral external swelling, and well in front of midlength. Inner lamellae lacking. Length of holotype (U.S.N.M. 117963) 0.27 mm, height 0.19 mm, thickness 0.12 mm. Relationships—The posteroventral longitudinal swelling serves to distinguish this species. It is also distinguished by its small size, and the present speci— mens possibly represent immature molts. The hinge— ment, overlap relationships, and lack of inner lamellae ally the species with Cytherella Jones. Occurrence—Upper part of the Sundance or Red— water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61f, g, i, k. Suborder PODOCOPA Sars, 1866 Family CYPRIDAE Baird, 1846 Genus MACROCYPRIS Brady, 1867 Macroeypris minutus Swain and Peterson, n. sp. Plate 1, figures 13—16 Shell sublanceolate in side View; highest about one- third from anterior end; dorsal margin moderately convex, slightly truncate behind and in front of point of greatest height; ventral margin nearly straight; anterior margin rounded, extended medially; posterior 10 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 margin bluntly acuminate, strongly extended below. Right valve larger than left, extending beyond the other along ventrum and along dorsal slopes. Valves compressed, thickest medially. Hingement simple; hinge surface of left valve slightly beveled above, along dorsal slopes, for reception of overlapping edge of right. Inner lamellae fairly broad; line of concrescence and inner margin coincide. Muscle scar not clearly observed but appears to consist of a slightly dorsomedian group of four spots of which the dorsal two are the largest. Neither radial nor nor- mal Canals were observed. Length of holotype (U.S.N.M. 117965) 0.39 mm, height 0.18 mm, thickness 0.07 mm. Relationships—This species is less elongated and smaller than most other described members of Macro- cypris. The overlapping right valve relates it to this genus although living species are much larger. Speci- mens described by Cooper (1946, pp. 61, 62) from the Pennsylvanian and by Alexander (1929, p. 59) from the Cretaceous are generally smaller than 1 mm, where- as living species are as much as 3 mm or more in length. Occurrence—(1) Upper part of the Sundance or Red— water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61e, h—k. (2) Swift formation, near Heath, Sec. 2, T. 14 N., R. 19 E. and Sec. 35, T. 15 N., R. 19 E., Fergus County, Montana; J—14a. (3) One mile south— west of Landusky, Sec. 32, T. 25 N., R. 24 E, Phillips County, Montana; J—22c, f. Family CYTHERIDAE Baird, 1850 Genus APARCHITOCYTHERE Swain and Peterson, new genus Shell subovate to subquadrate; hinge margin nearly straight, frequently occurring mostly posterior to point of greatest height; ventrum gently convex to sinuous; terminal margins broadly rounded. Left valve larger than right, but right overlaps left along hinge. Valves strongly convex. Surface not strongly ornamented. Hinge of left valve consists of a terminal short elongate socket—groove, and an interterminal narrow bar with weak groove behind it. Hinge of right valve consists of corresponding terminal elongate tooth eleva- tions formed of valve edge, and an interterminal groove. Inner lamellae distinct and heavily calcified but narrow; line of concrescence and inner margin slightly separated. Radial canals few and widely spaced; normal canals likewise few. Muscle scar consists of a median vertical row of three or four spots, and two more anterior spots; a low obscure transverse ridge lies on valve interior just behind muscle scar. In the type species, female dimorphs larger and more subquadrate than males. Type species.—Aparchitocythere typica Swain and Peterson, n. sp. Geologic Ranger—Upper Jurassic. The species de- scribed as Apatocythere? loeblichorum Swain and Peterson (1951) from the Redwater shale member of the Sun- dance formation are referred to Aparchitocythere (see p. 11). An undescribed species of the genus occurs in the lower part of the Sundance formation. Aparchitocythere typica Swain and Peterson, nasp. Plate 1, figures 8, 9, 17, 18, 21, 22 Shell subovate to subquadrate in side view. Dimor- phism prominently exhibited, with males shorter, more ovate in outline than females. Dorsal margin moder- ately convex in males,.straighter but somewhat sinuous and about three—fifths of shell length in females. Ventral margin slightly convex in males, sinuous in females. Anterior margin broadly rounded, slightly extended below; posterior margin more narrowly rounded and extended medially in males, about equal in breadth to anterior and extended above in females. Left valve larger than right, overlapping and extending beyond the other along free margins; dorsally, right valve overlaps and extends beyond left. Valves strongly convex, thickest about one—third from posterior end; females slightly compressed anterior to position of greatest thickness. In some specimens, particularly in females, there is a very weak transverse dorsomedian furrow that is represented on interior surface by a slight ridge. Surface smooth except for widely scattered tiny pits that mark external openings of normal canals. For a discussion of internal features, refer to the description of the genus. Length of male paratype (U.S.N.M. 116641, pl. 1, fig. 22) 0.72 mm, height 0.47 mm, thickness 0.40 mm. Length of female holotype (U.S.N.M. 116642, pl. 1, fig. 9) 0.91 mm, height 0.56 mm, thickness 0.44 mm. Relationships—There are no known close relatives of this species in the Mesozoic, except Aparchitocythere loeblz'chorum (Swain and Peterson) from the Redwater member at its type locality and an undescribed species in the lower part of the Sundance. A. loeblichorum is much shorter and has the dorsal margin more convex than the present species. In the Miocene of the south— eastern United States there; are several species of Basslerites Howe that are similar to the new species in shape, but the hinge of Basslem'tes consists of strong knoblike teeth and sockets. . Occurrence—(1) Upper part of the Sundance or Redwater shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61d, f—h, l—p. (2) Swift forma- tion, southwest corner of Red Dome, Sec. 19, T. 7 S., OSTRACODES FROM THE UPPER PART OF THE SUNDANCE FORMATION 11 R. 24 E., Carbon County, Montana; J—10b, c, llc, d, 12a. (3) Swift formation, near Heath, Sec. 2, T. 14 N., R. 19 E. and Sec. 35, T. 15 N., R. 19 E., Fergus County, Montana; J—14a. (4) Swift formation, one mile south- west of Landusky, Sec. 32, T. 25 N., R. 24 E., Phillips County, Montana; J—22d. (5) Shoshone River gorge, 2 miles west of Cody, Wyoming; J—43b, c. Aparchitocythere loeblichorum (Swain and Peterson) Plate 1, figures 19, 20, 23—25 Apatocythere loeblichorum Swain and Peterson, 1951, Jour. Pal- eontology, v0]. 25, p. 799, pl. 113, figs. 3—5. Shell features that were not observed in the rather poorly preserved specimens on which the species was based are as follows: Dimorphism in the species is represented by subovate specimens like the holotype, presumably males, and more elongated subquadrate specimens, presumably females. The right valve overlaps and extends beyond the left along the hinge conspicuously in male dimorphs, less so in females. The right valve bears a hinge groove for reception of edge of left, and there are small ter- minal notches in the left valve hinge for reception of corresponding slight elevations in right. The coarse weak surface pitting is supplemented in some specimens by a faint and much finer pitting. Length of female shell (U.S.N.M. 116647, pl. 1, fig. 19) 0.44 mm, height 0.30 mm, thickness 0.22 mm. Length of a male shell (U.S.N.M. 116649, pl. 1, fig. 23) 0.38 mm, height 0.30 mm, thickness 0.20 mm. Occurrence—(1) Upper part of the Sundance or Redwater shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61a. (2) One mile southwest of Landusky, Sec. 32, T. 25 N., R. 24 E., Phillips County, Montana; J—22d. (3) The species was originally de- scribed from 100—105 feet above base of the Redwater shale member of the Sundance formation at the type locality, Sec. 2, T. 7 N., R. 1 E., Butte County, South Dakota. Genus MONOCERATINA Roth Monoceratina sundancensis Swain and Peterson Plate 2, figures 1—7 Monoceratina sundancensis Swain and Peterson, 1951, Jour. Pal- eontology, vol. 25, p. 803, pl. 114, figs. 7—15. Shell features not given in the original description are: left valve extends beyond right along anterior dorsal slope, but right valve extends beyond left in mid—dorsal region as previously stated; in some speci- mens swollen ventral surface bears a low alaform ridge. Length of a figured specimen (U.S.N.M. 116659, pl. 2, fig. 1) 0.36 mm, height 0.19 mm, thickness 0.18 mm. Occurrence.——(1) Upper part of the Sundance or Redwater shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61e—j. (2) Swift formation, Red Dome, Sec 19, T. 7 S., R. 24 E., Carbon County, Montana; J—llb,c,d. (3) Swift formation, near Heath, Sec. 2,T. 14 S., R. 19 E. and Sec. 35,T. 15 N., R. 19 E., Fergus County, Montana; J—14a. (4) Swift formation, one mile southwest of Piper, Sec. 17, T. 14 N., R. 20 E., Fergus County, Montana; J—19. (5) Swift formation, one mile southwest of Landusky, Sec. 32, T. 25 N., R. 24 E., Phillips County, Montana; J—22a, f, j. (6) The species was first described from 40 to 59 feet above base of Redwater shale member at its type locality, Sec. 2, T. 7 N., R. 1 E., Butte County, South Dakota. Genus Camptocythere Triebel, 1950 Shell subovate in side view; dorsum moderately to strongly convex; ventrum less convex; ends rounded, posterior more pointed than anterior. Right valve strongly overlaps left dorsally, left valve overlaps right ventrally and terminally. Valves moderately convex, thickest medially. Surface smooth, pitted and in some species with short median subvertical furrows. Hinge of right valve consists of terminal small elon- gate teeth, and intervening narrow bar dorsad of which is a broad accommodation groove; hinge of left valve consists of terminal weak sockets and intervening narrow groove. Muscle scar consists of a median subvertical row of four spots and two additional more anterior spots. Inner lamellae narrow, line of concrescence and inner margin nearly or actually coinciding. Radial canals simple and widely spaced (after Triebel, 1950). Type Species.—0amptocythere praecox Triebel, 1950. Geologic range and geographic Distribution—Middle and upper Jurassic, Europe, North America. Camptocythere elliptica Swain and Peterson, n. sp. Plate 2, figures 8—13 Shell elongate—subelliptical in lateral View; hinge margin straight to slightly sinuous and half to two- thirds of shell length; ventral margin nearly straight and subparallel to dorsum; anterior margin broadly rounded, slightly extended below, truncate above; pos- terior margin more narrowly rounded, extended dor- somedially. Left valve larger than right, overlapping along free margins and extending beyond right ter— minally; dorsally, right valve overlaps and extends beyond left. Valves moderately convex, thickest post- medially and ventrally, ventral surface flattened. 12 - SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 A weak sulcus occurs in mid-dorsal region; in pre- sumed female dimorphs valve markedly swollen pos— terior to sulcus resulting in a slight overhang along posterior half of dorsal and ventral margins. In some specimens, particularly in females, there is a low, rounded, slightly anteromedian node representing the position of the adductor muscle scar. Well—preserved specimens have surface Of valves very finely pitted. Hinge of right valve consists of terminal small tooth- like elevations, of which the anterior is the higher, and an interterminal groove. Hinge of left valve corre- spondingly consists of terminal shallow sockets and an interterminal bar formed of the valve edge. Muscle scar a slightly anteromedian vertical row of four spots and an additional more anterior spot. Inner lamellae of moderate width, broadest anteriorly; line of con- crescence and inner margin slightly separated. Radial canals few and widely spaced. Length of holotype (U.S.N.M. 116666, probably a female) 0.49 mm, height 0.28 mm, thickness 0.23 mm. Relationships—The general shape, flattened ventrum and hingement ally this species with Oamptocythere Triebel. Aparchitocythere Swain and Peterson, n. gen., is closely similar but lacks the flattened ventrum and ventral swelling of Oamptocythere. Monocemtina sun— dancensis Swain and Peterson, and Leptocythere imlayi Swain and Peterson although more elongate and differ- ing in other respects of shape are nevertheless like Camptocythere in hingement, flattened ventrum, dorsal overlap of right valve, and weak median sulcus. All of these forms appear to be ancestrally related, and the species we have referred to Monoceratina and Leptocy- there may require assignment to new genera. Occurrence—Upper part of the Sundance or Red- water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J~61f-n. Genus LEPTOCYTHERE Sars, 1925 Leptocythere imlayi Swain and Peterson Plate 1, figures 26—30 Leptocythere imlayi Swain and Peterson, 1951, Jour. Paleontology, vol. 25, pp. 804—805, pl. 114, figs. 16~24. Three immature molts and two adult shells of this species are illustrated to show the close relationship to Monoceratina Roth. In the molts the shell is much shorter, more pointed and more strongly extended pos- teriorly than in the adult. The posteroventral surface of the immature valve is swollen to form a slight over— hang; the posterior end of the shell is compressed. The hinge of the right valve bears slight terminal elevations,- but is otherwise smooth. The inner lamellae are narrow but distinctly developed. Length of figured adult specimen (U.S.N.M. 116653, pl. 1, fig. 27) 0.51 ~mm, height 0.28 mm, thickness 0.19 mm. Length of an immature molt (U.S.N.M. 116654, pl. 1, fig. 28) 0.36 mm, height 0.24 mm, thick— ness 0.16 mm. I Occurrence—(1) Upper part of the Sundance or Red- water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61h—n. (2) Swift formation, near Heath, Sec. 2, T. 14 N., R. 19 E. and Sec. 35, T. 15 N., R. 19 E., Fergus County, Montana; J—14a. (3) Swift formation, one mile southwest of Piper, Sec. 17, T. 14 N., R. 20 E., Fergus County, Montana; J—19. (4) Swift formation, one mile southwest of Landusky, Phillips County, Montana; J—22j. Genus CYTHERURA Sars, 1866 Cytherura? lanceolata Swain and Peterson Plate 1, figures 31—33 Cytherura? lanceolata Swain and Peterson, 1951, Jour. Paleon— tology, vol. 25, pp. 802—803, pl. 114, figs. 5, 6, 27, 28. This species is characterized by subovate to subquad- rate outline with well defined anterior cardinal angula- tion; ventral portion of anterior margin extended and bluntly acuminate, short posteroventral alae, and right valve overlapping along the hinge. Length of a figured specimen (U.S.N.M. 116656, pl. 1, fig. 31) 0.39 mm, height 0.23 mm, thickness 0.16 mm. Occurrence—(1) Upper part of the Sundance or Red- water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61e, g, h, i, j, k, m. (2) Swift formation, Red Dome, Sec. 19, T. 7 S., R. 24 13., Carbon County, Montana; J—llc, d. (3) Swift formation, near Heath, Sec. 2, T. 14 N., R. 19 E. and Sec. 35, T. 15 N., R. 19 E, Fergus County, Montana, J—14a. (4) Swift for— mation, Sec. 32, T. 25 N., R. 24 E., Phillips County, Montana; J—22f. (5) The species was originally des— cribed from 40 to 63 feet above base of Redwater shale member at its type locality Sec. 2, T. 7 N., R. 1 E., Butte County, South Dakota. Genus PROGONOCYTHERE Sylvester-Bradley, 1948 Progonocythere hieroglyphica Swain and Peterson Plate 2, figures 18—20 . Progonocyzhere hieroglyphica Swain and Peterson, 1951, Jour. Paleontology, vol. 25, pp. 800—802, pl. 113, figs. 10—18. The outstanding shell characteristics of this species are: small size (about 0.6 mm long), subquadrate out- line; left valve slightly the larger; surface ornamented by two or three Outer concentric ridges, four or five OSTRACODES FROM THE UPPER PART OF THE SUNDANCE FORMATION 13 postmedian ventral ridges, and several diversely arranged anteromedian ridges; a short Oblique antero- median sulcus; hinge of left valve consists of terminal elongate denticulate sockets and an interterminal weakly crenulate bar; that of right valve the antithesis; inner lamellae fairly broad. Length of a figured specimen (U.S.N.M. 116677) 0.56 mm, height 0.27 mm, thickness 0.30 mm. Occurrence .—(1) Sundance formation, Redwater shale member, Sec. 3, T. 6 N., R. 2 E., Lawrence County, South Dakota; J—47c, e—g. (2) Sundance formation, Redwater shale member, Sec 18, T. 45 N., R. 60 W., Weston County, Wyoming; J—52f. (3) Sundance for- mation, Redwater shale member, Sec. 14, T. 7 S., R. 3 E., Fall River County, South Dakota; J—56d. (4) Upper part Of the Sundance or Redwater shale member, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61b. (5) Swift formation, Red Dome, Sec. 19, T. 7 S., R. 24 E., Carbon County, Montana; J—10a. (6) Swift formation, one mile south- west of Piper, Sec. 17, T. 14 N., R. 20 E., Fergus County, Montana; J—19. (7) Swift formation, one mile south- west Of Landusky, Sec. 32, T. 25 N., R. 24 13., Phillips County, Montana; J—22b, c, d, f, g. (8) Swift formation Shoshone River Gorge, 2 miles west of Cody, Wyoming; J—43b. (9) The species was originally described from 33—73 feet above base‘of Redwater shale member of Sundance formation at its type locality in Sec. 2, T. 7 N., R. 1 E., Butte County, South Dakota. Progonocythere crowcreekensis Swain and Peterson Plate 2, figures 22—25 Progonocythere crowcreekensis Swain and Peterson, 1951, Jour. Paleontology, vol. 25, p. 802, pl. 114, figs. 1—4. This species is characterized by subquadrate outline, coarsely reticulateand pustulose surface, prominent anteromedian tubercle, and anteroventral marginal spines. It is‘ about one-third larger than P. hiero- glyphica, Swain and Peterson. Length of a figured female shell (U.S.N.M. 116681, pl. 2, fig. 23) 1.07 mm, height 0.52 mm, thickness 0.56 mm; length of a figured male (U.S.N.M. 116680, pl. 2, fig. 22) 0.85 mm, height 0.45 mm, thickness 0.46 mm. Occurrence—(1) Sundance formation, Redwater shale member, Sec. 3, T. 6 N., R. 2 E., Lawrence County, South Dakota; J—47f. (2) Sundance formation, Red- watershale member, Sec. 18, T. 45 N., R. 60 W., Weston County, Wyoming; J—52e, f. (3) Upper part of the Sundance or Redwater shale member, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61b—d. (4) Swift formation, Red Dome, Sec. 19, T. 7 S., R. 24 E., Carbon County, 1r/Iontana; J—lOa—c. (5) Swift formation, Sec. 17, T. 14 N., R. 20 E., Fergus County, Montana; J—19. (6) Swift formation, Sec. 32, T. 25 N., R. 24 E., Phillips County, Montana; J—22b, h. (7) Swift formation, Shoshone River Gorge, 2 miles west of Cody, Wyoming; J—43b. (8) The species was described from 40 to 59 feet above base of Redwater shale member at its type locality Sec. 2, T. 7 N., R. 1 E., Butte County, South Dakota. Genus PROTOCYTHERE Triebel. 1938 Protocythere quadricarinata Swain and Peterson, n. sp. Plate 2, figures 14—17, 21 Shell sublanceolate in side View; highest about one- fourth from anterior end; hinge margin nearly straight, about two—thirds of shell length, ventral margin slightly convex, converging posteriorly toward dorsum; anterior margin rounded, extended below; posterior margin more pointed, strongly extended medially. Left valve larger than right, extending beyond the other around entire periphery, but most strongly along ventrum and along dorsal slopes. Convexity of valves moderate, greatest thickness posteromedian ; middle of each valve flattened in some specimens. Ends Of each valve slightly com- pressed but more so in right valve than in left; left valve with terminal low marginal rims. Middle two-thirds of each valve bears four longi- tudinal low ridges or SWellings; dorsal ridge highest medially, narrow behind and broader in front; two median ridges merging anterior to midlength; ventral ridge barely differentiated from general surface of valve below. General surface bears a few scattered pits. Hinge of left valve consists of an anterior, elongate, crenulate socket, a posterior shorter crenulate socket, and an interterminal bar the ventral slope of which bears an obscurely crenulate weak incision; dorsad of bar is an accommodation shelf . Hinge of right valve consists of terminal elongate, crenulate teeth; intervening hinge edge recessed and in the present material only obscurely crenulate. Inner lamellae of moderate width; line of concrescence and inner margin coincide) Muscle scar not observed. v Length of holotype (U.S.N.M. 116672), 0.65 mm, height 0.32 mm, thickness 0.31 mm. Relationships—The general shape, overlap, hinge- ment and longitudinal ridges of this form conform to Protocythere Triebel. The double median ridge distin- guishes it from other described species. Occurrence.——(1) Upper part of the Sundance or Redwater shale member Of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—610, d. (2) Swift formation, Red Dome, Sec. 19, T. 7 S., R. 24 E., Carbon County, 14 SHORTER “CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 Montana; J—10b, c. (3) Swift formation, Sec. 32, T. 25 N., R. 24 E., Phillips County, Montana; J—22f, g. Genus CYTHEREIS Jones, 1849 Cythereis? zygoventralis Swain and Peterson, n. sp. Plate 2, figures 26—32 Shell subquadrate in side View; highest about one- fifth from anterior end; hinge margin nearly straight, about two-thirds of shell length, and with rather Well defined cardinal angles of which the anterior is the more obtuse; ventral margin nearly straight to gently convex, converging slightly with dorsum posteriorly; anterior margin broadly rounded, extended below, truncate above; posterior margin narrower, subtruncate. Left valve slightly larger than right, overlapping slightly along ventrum and extending beyond the other antero— dorsally and posteriorly. Valves moderately convex, thick in ventral half, especially thick in posteroventral region. Surface strongly and coarsely reticulate; dorsal and terminal margins bear narrow knife—edge rims; three prominent, longitudinal, narrow ridges in middle part of each valve: one above and two below midshell. The more ventral ridge typically strongly elevated near its posterior end and, in side view, overhanging ventral margin. Between the two ventral ridges and anterad of midlength is a short fourth ridge. Ends of ridges connected except posterior ends of dorsal and ventral ridges. Mid-dorsally are two or three short ridgelike elevations; anterodorsally, a short spur projects ven- trally from marginal rim; a shallow sulcus lies behind this spur. Hinge of right valve consists of an anterior elliptical tooth that bears a weak transverse groove, an inter? terminal groove, broadest anteriorly and very narrow medially, and a posterior rounded tooth. Hinge of left valve is composed of an anterior socket, an inter- terminal ridge, and a posterior socket. Muscle scar consists of a slightly anteromedian subvertical row of four tiny, closely spaced spots and a more anterior spot. Inner lamellae of moderate width with smooth inner margin. The latter and the line of concresence are slightly separated. ' Dimorphism in the species is represented by larger, more subquadrate specimens that are presumably females. , Length of male holotype (U.S.N.M. 1.16685) 0.82 mm, height 0.45 mm, thickness 0.35 mm. Length of female paratype (U.S.N.M.‘116687), 0.89 mm, height 0.44 mm, thickness 0.35 mm. Relationships.-—Several ostracodes that are illustrated but not formally described or named by Brand (1949, pls. XI—XIV) as “ostracode 72, ostracode 88b, and ostracode 89a,b” from the upperpart of the Middle Jurassic (Dogger) of northwestern Germany resemble 0.? zygoventmlis but Brand’s illustrations are not clear enough to permit detailed comparisons. The species lacks the crenulate hinge, median node, and except in immature molts the posterior strongly elevated points, features typical of Cythereis, but seems closer to that genus than to any other. There is a slight tendency for the posterior end to be compressed and the adjacent surface to have its ornamental ridges a little more strongly elevated there than elsewhere, features that are reminiscent of Oythereis. For the time being the new species will be referred to Oythereis, although probably the discovery of related species Will require establishment of a new genus. Specimens show a great deal of variation, especially in surface ornamentation. In some specimens the reticulations are very weak and the longitudinal ridges provide almost the only ornamentation; in other specimens the reticulations are deeply developed and nearly obscure the longitudinal ridges. The strongly elevated ventral ridges in the presumed male dimorphs provide a subalate appearance, and result in a flattened aspect of the ventrum; the female dimorphs lack this feature. _ Immature molts of the species are rare in the present collection except in samples from locality J—61j. The surfaces of these immature molts are finely pitted, the reticulations are developed only in patches and the longitudinal ridges are very delicate but fairly well defined; the ridge along the dorsum and the two ventral ridges terminate posteriorly in prominent elevations in several of the molts, and there is a terminal point on the submedian ridge of some molts. The ventral ridges in the earlier molts form short but conspicuous alae, and the posterior end of the shell is distinctly compressed. Occurrence.—Upper part of the Sundance or Red- water shale member of the Sundance formation, Red Gulch, Sec. 22, T. 58 N., R. 89 W., Sheridan County, Wyoming; J—61g—l. REFERENCES Alexander, C. 1., 1929, Ostracoda of the Cretaceous of North Texas: Univ. Texas Bull. 2907, p. 1—137, 2 figs., 9 pls.. 1 chart. Brand, E., 1949, Neue Ergebnisse zur mikropalaontologischen Gliederung des nordwestdeutschen Dogger und Valendis, in Bentz, A., Erdfil und Tektonik in Nordwestdeutschland, p. 335—348, figs. 1—5, pls. 10—14. Cooper, C. L., 1946, Pennsylvanian ostracodes of Illinois: Ill. Geol. Surv. Bull. 70, p. 1—177, figs. 1-36, pls. 1—21, 1 chart. Geis, H. L., 1932, Some ostracodes from the Salem limestone, Mississippian of Indiana: Jour. Paleontology, vol 6, pp. 149—188, pls. 22—26. OSTRACODES FROM THE UPPER PART OF THE SUNDANCE FORMATION 15 Imlay, R. W., 1944, Marine Jurassic of Black Hills area, South Dakota and Wyoming: Bull. Am. Assoc. Petroleum Geologists, vol. 31, p. 227—273, 3 figs. 1949, Paleogeography of Jurassic seas in the western interior of the United States: Rept. of the Committee on a Treatise on Marine Ecology and Paleoecology 1948—1949, no. 9, p. 72—104, 1 table, 8 figs. lmlay, R. W., Gardner, L. S., Rogers, C. P., Jr. and Hadley, H. D., 1948, Marine Jurassic formations of Montana: U. S. Geol. Survey Prelim. Chart 32, Oil and Gas Invest. Ser. Kellett, B., 1933, Ostracodes of the Upper Pennsylvanian and the Lower Permian strata of Kansas: I. The Aparchitidae, Beyrichiidae, Glyptopleuridae, Kloedenellidae, Kirkbyidae and Youngiellidae: Jour. Paleontology, v01. 7, pp. 59—108, pls. 13—16. —~— 1935, Ostracodes of the Upper Pennsylvanian and the Lower Permian strata of Kansas: III. Bairdiidae (con- cluded), Cytherellidae, Cypridinidae, Entomoconchidae, Cytheridae and Cypridae: Jour. Paleontology, vol. 9, pp. 132—166, pls. 16—18. 1936, Carboniferous ostracodes: Jour. Paleontology, vol. 10, pp. 769—785. Loeblich, A. R., Jr. and Tappan, Helen, 1950a, North American Jurassic Foraminifera: I. The Type Redwater Shale (0x- fordian) of South Dakota: Jour. Paleontology, vol 24, pp. 39—60, pls. 11—16. Loeblich, A. R., Jr. and Tappan, Helen, 1950b, North American Jurassic Foraminifera: II. Characteristic western interior Callovian species: Jour. Wash. Acad. Sci., vol. 40, pp. 1—19. Scott, H. W., 1944, Muscle scar patterns on some upper Paleozoic I ostracodes: Jour. Paleontology, vol. 18, pp. 162—171, 28 text figs. Swain, F. M., 1949, Upper Jurassic of northeastern Texas: Bull. \ Am. Assoc. Petroleum Geologists, vol. 33, pp. 1206—1250, 3 pls., 10 figs., 3 tables. Swain, F. M. and Peterson, J. A., 1951, Ostracoda from the Redwater shale member of the Sundance formation at the type locality, Butte County, S. D.: Jour. Paleontology, vol. 25, pp. 796—807, pls. 113, 114. Sylvester-Bradley, P. C., 1948, Bathonian ostracodes from the Boueti bed of Langton Herring, Dorset: Geol. Mag., vol. 85, no. 4, pp. 185—204, figs. 1—7, pls. 12—15. Triebel, E., 1938, Ostracoden-Untersuchungen: I. Protocythere und Exophthalmocwhere, zwei neue Ostracoden-Gattungen aus der deutschen Kreide: Senckenbergiana, vol. 20, pp. 179—200, pls. 1—3. 1950, Campiocythere, ein neue Ostracoden—Gattung aus dem Dogger Norddeutschlands: Senckenbergiana, vol. 31, pp. 197—208, pls. 1—3. INDEX [Italic numbers indicate descriptions] A Page Abstract ...................................................................... l Amphmiles ................................................. 8, 9 Aparchitocuthere. _ . ................................................. 8, 10, 12 Ioeblfchorum..-. ........................................... l, 6, 7,10, 11, pl. 1 typfca ...................... 1,6. 7, 10, pl. 1 Apatocythere loebllchomm ..................................................... 10, 11 Astamfraom: .............................................................. 5 asmtscua, Pmtacrtnm ........................................................ 5 7 comanchmsia, therella.. ................................. 9 Corbicellopsts £nomata. ___________________________ 5 craaaa, Basalerella ........................................... 8 crowcreekemls, Proaonocythm.. ....................... l, 6, 7, 8, 13,1)1. 2 curta, Eumtcrotia .......................... 5 . Cypridae ......................... 1, F, 9 Cytherels .......................... 8 swoomtralis .................... 1,6,6,9,13, pl. 2 Cutherdla ....................................... 7 cmnanchmsfs..- ................... 9 paramucmterl ............. .. 1,6, 7. 9, pl. 1 scam ________________________________ 9 omropleura. .. 1, 6, .9, pl. 1 Cytherellidae ........................... 1, 7, 9 Cytherelloidea Sp .................. 7 Cytherldae...- 1,8—9, 1o __ 8 l Cyzhemra.-.- ....... 8 1 sp ........................................................................ 7 D . distema, Elllpaella ............................................................ 8 E Ellipsella ..................................................................... .n; elllzvtica, Campiocythcre. .__ mmopleum ________________________________________________ Eumicrotis curta. orbtculata ................................................................. 5 F fragilis, Asmm? ............................................................... 5 G Glyptopleurldae .............................................................. 8 G, I. . , 4'. _____________ 8 Gryphaea mbraacemis .................................. 3 5 H Haplocvtherldea ............................................. 8 hieroglyphlca, Prommocytherc ..... . 1,6, 7, 8, 12, pl. 2 Hulett sandstone member, sections ........................................... 3, 4, 5 I Imlay, Ralph, and Loeblich, A. R., Jr., sections measured ____________________ 2-7 Specimens collected. ........ 1 imlagi, T , ‘ ... ............... 1,6, 7,13, 111.] inomota, Corbfcdlopsts-. ....... 5 Introduction..._.._............-.......-.._.......-......--._..........___.-_ 1 K Page thbya " " m ............................. 8 Kirkbyidae ................................................................... 8 Kloedenellidae ................................................................ 8 Kootenai formation, section ___________________________________________________ 2 L Lak member, sections ........................................................ 4, 5 Ianceoluta, Cyzherura? _ 1, 6, 7, 19, pl. 1 Leptocuthere ............................................ 8, 12. tmlayl ............. 1, 6. 7, 12, pl. 1 lenocmhere ............ 7 "Maui, Kirkby_a...--.____-_-__.-.-_-.-_____-__-._--.___.___--.-._-_.--_.-__;- 8 Localities, list and map _______________________________________________________ 2 Loeblich, A. R., J12, specimens collected by ................................... 1 Iocblichoru-m, Apawcmherc.... _ . ......................................... 10 laebllchorum, Aparchhocwhere ......................................... 1, 6, 7,11, pl. 1 M Macracm/m ................................................................ 7 mfnuma ......................... .. 1,6, 7,9, pl. 1 Monoceraflna. .-. . .1 ...... 7, 8, 12 sundancensia ............................. . 1, 6, 7,11, pl. 2 monopleum, Eridocomha ________________________________________________ 1 Morrison formation, sections __________________________________________________ 2-3, 4 N nebrascemts, Gryphaeu ........................................................ 3 0 orbtculata, Eumlcrotis _________________________________________________________ 5 Orthcmotacythere.... 7 Ostra esp ..................................................................... 5 P Pachmeuthis sp ............................................................... 5 Paracypris ............. 8 parumuensmi, Catherefla ............................................... 1, 6, 7, 9, pl. 1 Pamparchh‘es _________________________________________________________________ 7 H Pentacrinus asteriscus _________________________________________________________ 5 Pleuromya aubelltptlca ........................................................ 5 Pontocypris ............ 7 praecoz‘, Cumptocythere ________________________________________________________ 11 Praaonocythcre __________________________________________________________ , ______ 8 crowireekmals.- ___ 1,6, 7, 8, 13,1)1. 2 hieroglyphica .................................................... 1, 6, 7, 8,12, pl. 2 sp.....___._...._.._.______.___..__.._.__.__._._..___...; _________________ 7 Protacythere ...... 8 quadrtcarhlata ____________________________________________________ 1, 6, 7, 18, p]. 2 Q quadricarmam, Prow'cylhere ........................................... 1, 6, 7, 13, pl. 2 Ouenstedtia submit .................................... ' ....................... 5 R Rodwatcr shale member, distribution of ostracodes ___________________________ 6 sections ________________________________________ -__ 3,4, 5 Relationships, ancestral, of Redwater ostracodes... 7—9 S Savayella ______________________________________________________________________ 8 atom, Cytherello ..................... 9 Spearfish formation, section... _ _______________________________ 4 Stockade Beaver shale member, sections. ............................... 3, 4, 5 aubelltpflca, Pleuromya ____________________________ 5 sublem, Oumstedtfa.. ............................... 5 Sundanoe formation, sections. . _____________________________________ 3—5 _ 1,6, 7,11,pl. 2 Swift formation, disttibution of ostracodes .................................... 7 samples ................................................................... 6—7 '1‘ Theriosynoecum ................ 7 Tomiella ............. 7 typica, Aparchitocythere ............................................... 1, 6, 7,10, pl. 1 V ventropleura, Cytherella ................................................... 1,6, 9. pl. 1 Z novmzram, Cytherels ............................................... 1, 6, 8, 9, 13, pl. 2 17 PLATES 1, 2 FIGURES 1—7. : 2. 3—6. 10-12. 11. 10, 12. 13—16. 13. 14—16. aaiz 18,21,22. - 9. 8. 17,18,2L 2a 19,20,23—25 » ia 20,23—25. 26—30. 26, 27. 28—30. 31—33. PLATE 1 Cytherella paramuensteri Swain and Peterson, n. sp. (p . 9) 7. Left side and posterior views of holotype, Loc. J—61h, U.S.N.M. 117957. Interior of paratype female right valve partly filled with matrix, Loc. J—61k, U.S.N.M. 1'17958. Interior of paratype female left valve, ventral view of paratype female shell, and dorsal view of paratype female shell, and ventral view of paratype male shell, Loc. J—61h, U.S.N.M. 117959-117962. All views X50. Cytherella ventropleum Swain and Peterson, n. sp. (p. 9) Left side of holotype, Loc. J—61g, U.S.N.M. 117963. Posterior and dorsal views of paratypes, Loc. J—61g, U.S.N.M. 117964. All views X74. Macrocypris minutus Swain and Peterson, n. Sp. (p. 9) ,3? Left side of holotype, Loo. J—61k, U.S.N.M. 117965. ‘ Left Kalve interigr, ventral view and dorsal View of three paratypes, Loc. J—61k, U.S.N.M. 11,1966, 116639—116640. 11 views X 1. v .- I Aparchitocythere typica Swain and Peterson, n. gem, n. Sp. (p. 10) Left side of holotype (U.S.N.M. 116642), a female X55, Loc. J—61h. Ventral view of a female paratype, X55, Loo. J—61h, U.S.N.M. 116643. Left valve interior, right valve interior and ventral views of three male paratypes, X56, Loc. J—61h, U.S.N.M. Right side of male paratype, X56, Loc. J-61h, U.S.N.M. 116641. Aparachitocythere loeblichorum (Swain and Peterson) (p. 11). Right side of female shell, X86, Loc. J—61a, U.S.N.M. 116647. Right side, dorsal view, left valve interior, right valve interior of four male specimens, X93, Loc. J—61a, U.S.N.M. 116648—116651. Leptocythere imlayi Swain and Peterson (p. 12). Dorsal view and right side of two shells, X76, Loc. J—61j, U.S.N.M. 116652, 116653. Right side and ventral views of an immature specimen and interior of an immature right valve, X72, Loc. J—61k, U.S.N.M. 116654, 116655. Cytherura? lanceolata Swain and Peterson (p. 12). Left side, dorsal and ventral views of three specimens, X92, Loc. J—61j, U.S.N.M. 116656—116658. ( [”1“le U *1R\F\ I’RHI'I'C">IU\ \I, |'\l’ltl( 3.1" (IYI‘HLRI‘ALIAII)\l‘. (IYI'RH)\L’ \,\l) (‘Yl'lllleDAli (.‘l‘l()|.()('.l(3\L SFRVEY PK(H-'l€>‘il()\;\[, PAPER 213 I’IA’I‘I", 2 (IYI‘HHRIDH‘i FIGURES 1—7. ! 5, 6. 8~13. 9—13: PLATE 2 M onoceratina sundancensis Swain and Peterson (p. 11). 7. Right side, left side, left valve interior, right valve interior, dorsal view of five specimens, X75, Loc. J—6 1e, U.S.N.M. 116659—116663. Posterior view, ventral View, X75, ‘Loc. J61j, U.S.N.M. 116664, 116665. Camptocythere elliptica Swain and Peterson, n. sp. (p. 11). 8 Right side of holotype, X71, Loc. J61j, U.S.N.M. 116666. Left side, left valve interior, right valve interior, dorsal view and ventral View of five paratypes, X71, Loc. J—61j, U.S.N.M. 116667—116671. 14—17, 21.Protocythere quadricarinata Swain and Peterson, n. sp. (p. 13). 14 15—17: 21. 18—20. Right side of holotype, X72, Loc. J—610, U.S.N.M. 116672. Left side. ventral View, and dorsal view of three paratypes, X72, Loc. J—6lc, U.S.N.M. 1166734116675. Interior of paratype left valve, partly filled with matrix, X72, Loc. J—61d, U.S.N.M. 116676. Progonocythere hieroglyphica Swain and Peterson (p. 12). Left side, dorsal View and right side of three specimens, X27, Loc. J—52f, U.S.N.M. 116677—116679. . Progonocythere crowc'reekensis Swain and Peterson (p. 13). . Right side of a male shell, X54, U.S.N.M. 116680. . Left side of a female shell, X46, U.S.N.M. 116681. . Ventral View of a male shell, X44, U.S.N.M. 116682. . Interior of a. left valve filled with matrix, X46, U.S.N.M. 116683. All from Loc. J~61d. . Cythereisf zygouentmlis Swain and Peterson, n. sp. (p . Exterior of immature left valve, Loc. J—61h U.S.N. . 116684. . Right side of holotype, a male, Loc. J—61j, U.S.N.M. 116685. . Interior of paratype left valve artly filled with matrix, Loc. J—61j, U.S.N.M. 116686. . Right side of female paratype, 0c. J—61j, U.S.N.M. 116687. . Right valve interior, dorsal view and left valve interior of three paratypes. All X55. U.S.N.M. 116688—116690. . 14). Tertiary Stratigraphy of South Carolina GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—3 GEOLOGICAL SCIENCES LIBRARY I Tertiary Stratigraphy ' of South Carolina '33) C. WYTHE COOKE and F. STEARNS MACNEIL SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 19—29 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—B A revised classification of Tertiary formations of the Coastal Plain, based mainly on new stratigraphic and paleontologie information UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1952 UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. — Price 15 cents (paper cover) CONTENTS . Page V Page Abstract ____________________________________________ 19 Paleocene C?) and Eocene series—Continued Introduction _______________________________________ 19 Deposits of Jackson age _________________________ 26 Paleocene (‘1’) and Eocene series ______________________ 19 Barnwell formation ____________ ' _____________ 26 Deposits of Wilcox age __________________________ 20 Oligocene series _____________________________________ 27 Deposits of Claiborne age ________________________ 21 Cooper marl- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _; _____________ 27 gsngareleli’ormatllon """"""""""""" :51; Miocene series__ _ _ _ _ _ _ _ _ _ _ _ - - - _ _- ____________________ 28 arley 111 mar """"""""""""""" Hawthorn formation ________________________ 28 McBean formation __________________________ 23 _ \ Santee limestone ____________________________ 24 References ----------------------------------------- 28 Castle Hayne limestone ______________________ 25 ILLUSTRATION Figure 2. Correlation of Tertiary formations of South Carolina __________________________________________________________ 20 m 993087—52 TERTIARY STRATIGRAPHY OF SOUTH CAROLINA By C. WYTHE COOKE AND F. STEARNS MACNEIL AB STRACT The following changes in the current classification of the Tertiary formations of South Carolina are proposed: The Black Mingo formatiOn, mainly of Wilcox age, may include some Paleo- cene deposits. The McBean formation, heretofore including all the deposits of known Claiborne age in’South Carolina, is re- stricted to the Ostrea sellacformis zone, of late middle Claiborne age, and the names Congaree formation (equivalent to the Tallahatta formation) and Warley Hill marl (equivalent to the Winona formation) are revived for deposits of early Claiborne and early middle Claiborne age. A large part of the deposits mapped as Barnwell formation (of Jackson age) proves to be Congaree. The Santee limestone, heretofore supposed to be of early Jackson age, represents the Ostrea sellaeformis zone and seems to be an offshore facies of the restricted McBean forma- tion. The Castle Hayne limestone, heretofore known only in North Carolina and referred to the middle Jackson, occurs under cover in South Carolina. Its fauna shows it to be equivalent to the Gosport sand, of late Claiborne age. The Cooper marl, currently referred.to the late Eocene (Jackson), is reassigned to the early Oligocene? on the basis of its mollusks, foramini- fers, and cetaceans. A gravelly facies of the Miocene Hawthorn formation similar to that in Georgia is recognized for the first time in South Carolina, where the formation had previously been recognized only by its offshore facies. INTRODUCTION The Coastal Plain of South Carolina has received somewhat less attention than that of the neighboring State of Georgia, and in comparison with the Coastal Plain of the Gulf States, which in recent years have been the center of extensive oil exploration, little is known. Since the days of Lyell only three general ac- counts of the stratigraphy of the Coastal Plainof South Carolina have been published, one by Tuomey in 1848, one by Sloan in 1908, and the most recent by Cooke in 1936 as Bulletin 867 of the United States Geological Survey. The present paper presents a revised classification of the Tertiary formations of South Carolina, and indi- cates some of the changes necessary on the existing geologic map of the State. However, the greater part of the information on which this revision is based comes from entirely new exposures and new collections of fossils, and even the interpretation of the molluscan faunas is based on revised knowledge of the range of species._ Travel 111 the Coastal Plain is now much easier and faster than it was before 1936. Many new roads and \ bridges have been built, and places formerly inacces- sible are now within easy reach. The spoil bank of the Santee—Cooper Diversion Canal, out about 1940, has brought to the surface an abundance of fossils of the. Santee limestone, including species that had not been collected since the 1830’s, when the original Santee Canal was dug. The. associated fauna of, the more characteristic of thesespecies is now known for the first time. New pits sunk in the flat, featureless Pleisto- cene plain yield unsuspected evidence as to the age of the underlying limestones. Since 1935 MacNeil has been making stratigraphic studies on the Tertiary formations of Mississippi, Ala- bama, Georgia, and Florida. These have resulted in more accurate information as to the geologic ranges of fossils, and familiarity with the stratigraphy of the formations containing them. Using this information he was able, during a three-week reconnaissance during 1950, presumably preliminary to the preparation of a new geologic map of the Tertiary formations of South Carolina, to make closer correlations with the type sec- tions in Mississippi and Alabama than had been possible in 1936. The writers made two short trips to South Carolina together in May and June of 1951. PALEOCENE (7) AND EOCENE SERIES The name Paleocene series was not adopted by the U. S. Geological Survey until after the publication of Cooke’s 1936 paper. The deposits in the southeastern States now referred to the Paleocene form the Midway group, which had previously been treated as the oldest division of the Eocene series. Since the removal of the ’Midway group to the Paleocene, the Eocene series in the Southern States has included only three groups—the Wilcox, Claiborne, and Jackson, represented in South Carolina, though the group names have not been ap- plied there. In addition there is somewhat meager evidence to indicate that the lowest of the units here recognized may include beds of both Paleocene and early Eocene (Wilcox) age. The only known representative of the Wilcox group in South Carolina is the Black Mingo formation. .There is some evidence that the beds now included in the Black Mingo may be in part of Paleoceneage, but the evidence is inconclusive. The Claiborne group is more fully 19 20 SHORTER CONTRIBUTIONS TO GHNERAL GEOLOGY, 1952 . . . . South North Mlssmsmpl Alabama Carolina Carolina g , E‘ ‘— —————— Ocala \ C coa sand ' go Yazoo clay 0 \ limestone = \ \ \member \ Barnwell 9 E — _ _) Sand, Silt, formation E and clay Moodys Branch formation WWW ; i & Cockfield formation 'Gosport sand Castle Hayne limestone :> _WANW\MNW Cook Mountain formation Ostrea sellaeformis zone McBean Santee limestone formation ‘ a. o 8 Sparta sand "3 Kb 3, (Kosciusko sand) E (Present) 1 2 v .9 h '6st W .8 E = E Zilpha clay % (Absent?) U "‘ Warle Hill ”'1 Ostrea smithvillensis zone Y1 Winona formation ————————————— mar Ostrea lisbonensis zone —W WW II! . " C 3 _ ongaree :1 Tallahatta formation , formation WWW Hatchetighee formation Bashi marl member a. :1 L90 E: Wilcox formation Tuscahoma sand 3 Nanafaha formation Black Mingo ’ _ — ____________ 'fonnation 2 . Fearn Springs sand member 1 Nonfossiliferous, nonglauconitic limestone at Cave Hall may be of this age. 2 May include some Paleocene. FIGURE 2.—Corre1ation of Tertiary formations of South Carolina. represented. As here revised it includes the Congaree Well. Residues of limestone of Jackson age certainly formation of early Claiborne age, the Warley Hill marl (both included in the McBean in Bulletin 867, Cooke, 1936) , the restricted McBean formation and its offshore equivalent the Santee limestone of middle Claiborne age, and the Castle Hayne limestone, as here restricted, of late Claiborne age. The Jackson group is repre- sentedby sandy limestone and perhaps down dip by a less sandy facies. At the present, outcrop beds of Jackson age are almost completely reduced to oxidized sandy residues. The name Barnwell formation was ap- plied to leached residues of the sandy limestone and no type locality was ever designated. It now appears that actually the railroad cut at Barnwell was made in a part of the Miocene Hawthorne formation, although many geologists must have regarded it as typical Barn- are present elsewhere in Barnwell County beneath the Hawthorne cover, and there is no reason why the name Barnwell cannot be applied to the unleached Jackson beds farther down the dip even though its type area falls entirely within the area of solution. The relationships of the Eocene formations in the Carolinas to one another and to the generalized stand- ard section in Georgia and Alabama are indicated in the correlation chart (fig. 2). DEPOSITS 0F WILCOX AGE The Black Mingo formation was referred to as being of Wilcox age (Cooke, 1936) primarily because of the presence of 0am arrosz's Aldrich. Although this oyster was stated by Aldrich to be from the Nanafalia TERTIARY STRATIGRAPHY OF SOUTH CAROLINA 21 formation, and has since been found to be restricted to it, in the correlation table (p. 40) the Black Mingo was placed opposite the Tuscahomasand of Alabama because of the occurrence in both of Tumm'tella mortom' Conrad, a species now known to be abundant in both the Nanafalia and the Tuscahoma. Mapped with this oyster-bearing bed were underlying siliceous clay- shales and an overlying massive red sand now known to be of early Claiborne age. A revised map would show the Black Mingo to be confined to a much smaller area, chiefly along valley floors. Beds mapped by Cooke (1936, pl. 2) as Black Creek (Cretaceous) forma- tion in western Sumter County are now regarded by MacNeil as Black Mingo as here restricted to the sili- ceous clay-shale and oyster-bearing bed, whereas the overlying more widely distributed sands in Richland, Lee, Sumter, Clarendon, and Williamsburg Counties that were mapped as Black Mingo are now placed by him in the Congaree formation, of early Claiborne age. Among fossils collected by Cooke in 1922 on the River Road 31/2 miles west of Pinewood, Sumter County (U.S.G.S. collection 10401) and referred to the Black Mingo formation (Cooke, 1936) is a Tum-itella he iden- tified as Turm'tella mortom' Conrad, a species typically of early Wilcox age. Later Bowles (1939, p. 271) iden- tified it as a new subspecies, T. mortom' mediam'a Bowles, which occurs typically in the lower part of the Midway group at Prairie Creek, Alabama. He found this same subspecies also in U.S.G.S. collection 10403, from the Kingstree road east of Deep Creek, 5 miles east of Manning, Clarendon County. On the basis Of this subspecies, Bowles was of the opinion that the Black Mingo is of Midway age, and not Wilcox, to which Cooke had tentatively referred it. The section at Warley Hill includes in the lower part (bed 3, p. 23) 8 feet of clay or shale overlain by a quartz- itic sand containing an oyster resembling Ostrea crenulimarginata Gabb, a species found at'many locali- ties in the Midway group in Alabama and western Georgia. Cooke (1936) included these beds in the Mo- Bean formation but they are now recognized as belong- ing to the Black Mingo formation. 0 8 tr e a crenulz'margz’mta is related to the Wilcox oyster 0. arrosis, but the material at hand more closely resembles the Midway species. The Black Mingo formation as mapped by Cooke (1936, pl. 2) is now known to have included some beds of early Claiborne age, and (even as here restricted) may include beds of both early Eocene and Paleocene ages. However, further subdivision of the Black Mingo is deferred until more definite evidence of Paleo- cene age is produced. If the lower shales of the Black Mingo should prove to be of Paleocene age, one of Sloan’s names (1907, 1908) , Rhems shale or Lang Syne shale, may be available. DEPOSITS OF CLAIBORNE AGE All the then-known deposits of Claiborne age were included by Cooke (1936) in one formation, the Me- Bean. This was the original usage in Georgia, where, according to Veatch and Stephenson (1911, p. 237), the McBean “formation is equal to the Tallahatta buhrstone plus the Lisbon formation of Alabama, and the top of it may include the base of the Gosport greensand of the Alabama section.” The Claiborne group throughout the States from Alabama to Texas has been divided into well-defined formations, each characterized by its distinctive fossils, and it now seems desirable to divide the McBean of Cooke (1936) along similar lines into three formations. Names proposed by Sloan in 1907 and 1908 are already available. For the lowest beds of Claiborne age, equivalent to the Tallahatta formation, Sloan’s name (1908, p. 455) Congaree is revived. For the intermediate beds, equivalent to the Winona forma- tion of Mississippi, Sloan’s name (1908, p. 457) Warley Hill is revived. The name McBean formation is re- tained, in a restricted sense, for the zone represented by the type locality of that formation. This zone, the Ostrea sellaeformz's, is equivalent to the Cook Mountain formation of Texas and‘Mississippi, the upper part of the middle Claiborne. MacNeil concluded in 1950, on the basis of field pro- files and a restudy of its molluscan fauna, that the San- tee limestone, long supposed to be of early Jackson age, represents the Ostrea sellaeformis zone of the Clai- borne group, equivalent to the restricted McBean for- mation, of which it is an offshore facies. Another astonishing result of the present investiga- tions is the discovery of the Castle Hayne limestone in South Carolina. That formation (typically developed in North Carolina, where it was called a marl) had been considered to be equivalent to the Santee limestone and to be of Jackson age. As here restricted, it is younger than the Santee and is of late Claiborne age, equivalent to the Gosport sand of Alabama and the Avon Park limestone of Florida. CONGAREE FORMATION Though Sloan’s “Congaree phase” (1908, p. 455) was vaguely defined, he evidently intended to“ include in it clay, sand, and buhrstone of early Claiborne age. Veatch and Stephenson (1911, pp. 238, 267) accepted Congaree in this sense for use in Georgia and described the Congaree clay as the basal member of the McBean formation, the oldest formation of Claiborne age known ’to them there. How much of their Congaree is really 22 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 Claiborne, however, is still uncertain; some deposits referred to it, notably the thick bed of fuller’s earth at , Pike’s Peak, in Twiggs County, Georgia, are now be— lieved to be of Jackson age because of their supposed equivalence to similar clay in Houston County, Ga., that lies above fossiliferous Jackson limestone. Cooke and Shearer (1918) supposed that all their Congaree clay member was of Jackson age and transferred it to the Barnwell formation under the name Twiggs clay member. . Later Cooke (1943, p. 61) restored that facies consisting of thin—bedded or laminated sand and clay » to the McBean formation but did not have an oppor- tunity to revise his map, which had been published in 1939. It now appears that the deposits of Claiborne and Jackson age have never been properly delimited in either eastern Georgia or South Carolina. Though Veatch and Stephenson (1911) mapped too much Clai- borne in Georgia, both Cooke (1939; 1943, pl. 1) and MacNeil (1947) showed too little. Cooke’s map of South Carolina (1936, pl. 2) included beds of Claiborne age in the supposed'Jackson south of the Congaree River, but north of that river the lower Claiborne was mapped as Black Mingo formation (Wilcox). After studying the section of Claiborne age of South Carolina and its fauna, MacNeil is of the opinion that a large part of the deposits in eastern Georgia mapped as Barnwell is of Claiborne age. This would include several of the better-known fossil localities, such as Little Keg Creek , (Cooke and Shearer, 1918, p. 48; Cooke, 1943, p. 55) and much of the Twiggs clay member of the Barnwell for- mation of eastern Georgia. The Congaree is now deemed of formational rank be- cause it is equivalent to the Tallahatta formation of Mississippi and Alabama, which presumably is sepa- rated from younger deposits by an erosion interval. The name Congaree formation rather than Congaree clay or shale is preferred because much’ sand as well as clay and shale are included. Sloan specified no single locality as the type of his Congaree “shale,” “sands,” or “buhrstone.” The name is evidently taken from the Congaree River, and it has been suggested (Cooke, 1936, p. 59) that Sloan’s lo- cality 505 on the Elmore Williams’ place at the head of First Creek, a tributary of the Congaree River, be regarded as typical. This locality is difficult to find without a guide. However, ledges of similar rock are exposed on the road south of Bull Swamp Creek 214 miles west-northwest of Swansea and also at a water- fall north of the east-west county road about 214 miles west by north of Swansea. ' ”A Tallahatta-like facies of the Congaree formation is well exposed in a cut on State Highway 33 half a mile east of Creston, Calhoun County, and west of Halfway Swamp; and for all practical purposes this can be regarded as a typical exposure. The section is as follows: Section in road out west of Halfway Swamp 0.5 mile east of Creston, Warley Hill marl. Feet 4. Coarse weathered sand _____________________ 5 3. Busty highly glauconitic sand _______________ 2 Unconformity? Congaree formation. 2. Alternating fine rusty unconsolidated sand and shale; borings in top ______________________ 5 1. Light-gray shale alternating with thin—bedded fine-grained sandstone, most beds less than 3 inches thick. Contains Anodontia? au- gustana Gardner. This bed closely resembles a facies of the Tallahatta formation. About ___ 16 The materials of the Congaree formation strongly resemble those of the Tallahatta formation. Both con- tain hard, brittle siltstone, which is the dominant com- ponent of the Tallahatta near the Mississippi-Alabama line. Well-sorted and poorly sorted sand are common to both formations. Brittle clay or fuller’s earth is a conspicuous feature of the Congaree in the Congaree Valley, although the larger clay masses are local lenses. In Aiken and Lexington Counties coarse to fine gravelly sand makes up the greater part of the formation. The Congaree formation in this area resembles the coarser facies of the Tallahatta in northern Mississippi. Several species of mollusks characteristic of the Ta]- lahatta occur also in South Carolina, and are restricted there to the Congaree formation. The recently de- scribed guide mollusk Anodontz'a? aagastana Gardner (1951, p. 9) was recorded by Gardner (1951, p. 10) from U.S.G.S. collection 7728, bed 8 of the section at Warley Hill (p. 23) and from a road cut on the south side of Halfway Swamp about 21/2 miles northwest of, Creston, Calhoun County. In Alabama this species occurs only in the Tallahatta formation. Ostrea john- soml Aldrich, a species now known to be confined to the Tallahatta, has been found near Salley (Cooke, 1936, p. 59) and 2 miles south'of Gaston (Cooke, 1936, p. 60). An oyster found in bed 2 of the section at Lang Syne (Cooke, 1936, p. 69) and reported as Ostrea divam'cata Lea seems to be an undescribed species, re- lated to 0. perplz'cata Dal], which occurs also in the Tallahatta. Hard sandstone and sand exposed in Aiken and Lex- ington Counties supposed by Cooke (1936) to be re- ferable to the Barnwell sand prove on further study to be of Congaree age. The most important of such outcrops are Calico Spring (locality 185, p. 93) , Decara— deaux place (locality 189, p. 94), and Bethel church TERTIARY STRATIGRAPHY or SOUTH CAROLINA V 23 (locality 190, p. 95). The last two localities/have yielded recognizable fossils formerly interpreted as of Jackson age. Two corals, however, Endopackys maclum'i (Lea) and Platytrochus stokesz’ (Lea), found elsewhere only in beds of Claiborne age, occur at both places. Fossils, including Turrz'tella mobeanensz’s Bowles, were recently found by D. H. Eargle and B. F. Buie in a tough siliceous clay near the mine of the Monetta Clay Company along Highway 39 about 11/2 miles northwest of New Holland Crossroads, Aiken County. This locality lies well within an area mapped as Cretaceous by Cooke in 1936. One of the striking features of the basal part of the Claiborne is the occurrence of boulders of pisolitic clay, mainly bauxitic. These boulders of pisolitic clay have been found by MacNeil to be common in eastern Georgia and as far east as Calhoun County, S. C., where they occur sporadically in a coarse sandy bed at the base of the Congaree formation and rest directly on dark shale of the Black Mingo forma- tion. The occurrence of these boulders of pisolitic clay at the base of the beds of Claiborne age agrees with what is now known of the age of the period of bauxiti- zation throughout the southeastern States. Bauxite is known to have been formed from clays both of Cre- taceous and of early Wilcox ages. All these clays are believed to have been bauxitize‘d during early Wilcox time. The occurrence of these reworked boulders of bauxite and pisolitic clay in deposits of the next great transgressive period—the Claiborne—is entirely con- sistent with the current dating of the bauxite. WARLEY HILL MARL The “Warley Hill phase,” described by Sloan (1908, p. 458), was included in the McBean formation by Cooke in 1936. The name is here revived in a restricted sense to include the dominantly glauconitic beds that intervene between the Congaree formation and the Ostrea sellaefomm's zone, or restricted McBean. The following section at Warley Hill is modified from Cooke (1936, p. 71). It is proposed to restrict the term Warley Hill marl to beds 9 and 10. This 10- cality, regarded as the type exposure of the formation, is on an abandoned road west of State Highway 267 and south of Warley Creek 3 miles north-northwest of Lone Star, Calhoun County, within the Elloree quadrangle. Section at Warley Hm Middle Eocene. Warley Hill marl (middle Claiborne). 10. Yellow sandy clay at base, passing into red— dish-yellow massive argillaceous sand con- taining many small grains of glauconite__ 16 Feet Middle Eocene—Continued Feet Warley Hill marl (middle Claiborne)—Continued 9. Fine green to yellow glauconitic sand contain- ing Venem‘cardia sp. and other fossils. In sharp contact with the bed below _______ 6 Congaree formation (lower Claiborne). 8. Greenish and yellow to gray brittle, nonplas- tic clay resembling fuller’s earth; a few casts of mollusks, including Anodontia? augustcma, Gardner ______________________ 14 . 7. Sparsely glauconitic light-weight gray to yel- low marl; a few casts of mollusks ________ 2174 6. Greenish-gray glauconitic sand with some clay at top; scattered pebbles 0.5 inch in diameter along base _____________________ 1 Paleocene( '2) and lower Eocene. Black Mingo formation. 5. Flaky brown nonplastic clay _______________ i. 4. Slightly coherent fine yellow or red sand, a decomposed sandstone, where fresh con— taining Ostrea crenulimargi-nata Gabb?____ 2 3. Compact, brittle blue-gray shale or clay (ful- ler’s earth) ; lower part with slaty cleav- age, upper part more massive and with conchoidal or hackly fracture ____________ 8 2. Fine gray to yellow sand mingled with black carbonaceous, sandy clay; a 6—inch in- durated ledge at top _____________________ 21/.) 1. Concealed to level of Warley Creek _________ 14 According to Sloan (1908, p. 302) the top of the War- ley Hill marl was exposed at Cave Hall and at Whaley’s mill' on Poplar Creek, both now in Calhoun County. At both localities it consisted of harsh, gray-green glauconitic marl. Sloan obtained well-preserved speci- mens of Ostrea lisbonemz's Harris (reported as 0. sel- laeformz's), a reliable and characteristic fossil of the lower part of the Winona formation of Mississippi and of the basal glauconitic marl of the Lisbon formation of Alabama, at Cave Hall. At both places, he says, the Warley Hill is overlain by the Santee limestone. The contact at Cave Hall seems to be unconformable, for Sloan describes it as undulating, and he reports rounded lumps of the Warley Hill marl in the base of the Santee limestone. Cave Hall is a deep ravine containing a flowing stream about 0.4 mile long entering Lake Marion 0.8 mile south of the embayed mouth of Halfway Swamp and 4.5 miles north-northeast of Elloree. Hard white limestone, presumably the IOWer part of the Santee limestone, though no fossils were found in it, is still exposed at the head of the ravine, but the Warley Hill marl there, which Sloan reports as rising 3 feet above the base line of the ravine, may now be covered by backwater from the lake. McBEAN FORMATION As originally defined by Veatch and Stephenson (1911, p. 237), the McBean formation of eastern Geor- 24 gia was equivalent to the combined Tallahatta forma- tion and Lisbon formation of the Alabama section. The McBean is here restricted to include only the Cook Mountain equivalent, the Ostrea sellaeformz's zone, of the Lisbon formation. This is represented at McBean, Georgia, and in South Carolina by white sandy marl and massive yellow or red sand, which appears to be at least partly residual from sandy marl. At Shell Bluff, l on the Georgia side of Savannah River, a bed of nearly 80 feet of sandy marl and limestone includes a 6—foot bed carrying large Ostrea sellaeformis (Cooke, 1943, p. 57). The massive sand contains local» patches of silicified shells, many species of which occur also in the Lisbon formation and in the Cook Mountain formation of Mis— sissippi. Fossils from several such patches in Orange- burg County are listed in Bulletin 867, notably Caw Caw Swamp (p. 63) , Pooser’s Hill (p. 64), and Orange- burg (p. 65). , A conspicuous component of the McBean formation in South Carolina is a very light weight sandstone or siltsone that appears to be a marl from which all the lime has been leached. This rock commonly contains Pteropsz's lap'idosa Conrad, a thin—shelled pelecypod with concentric undulations that seems to. be confined to the McBean. SANTEE LIMESTONE The “Santee beds” were first correlated with the Jackson “stage” by Dall (1898, p. 342), though he says: “Tuomey included Claibornian as well as J acksonian marls in his series. The term as adopted here refers to the upper green marls from which Zeuglodon has been obtained.” Dall may have had in mind the Cooper marl rather than the Santee limestone as those forma— tions are now divided, though no true zeuglodonts are known from the Cooper. The “Zenglodon” of Tuomey was a primitive toothed whale. It was found in the Cooper. The only zeuglodontid from South Carolina, Domdon serratus Gibbes, probably was found either in the Santee limestone or in the Castle Hayne limestone. The Jackson age of the Santee limestone was accepted by Canu and Bassler (1920), who referred the large fauna of Bryozoa at Eutaw Springs and Leneudes Ferry to the “middle J acksonian.” They listed a total of 130 species from the two places. Eighty-one of these species are reported also from Wilmington, N. C., and 58 from the Ocala limestone in Georgia. The Bryozoa from Wilmington, N. C., are for the most part from the Castle Hayne limestone, though some may have come from the Santee limestone, which underlies it there. It is not surprising that the faunas of the Santee, Castle Hayne, and Ocala limestones are some— SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 What similar, for these three formations represent sim- ilar facies. The Santee and Castle Hayne faunas were not recognized as of Claiborne age because no similar bryozoan-bearing limestone facies occurs in the Claiborne west of the Carolinas. , . The most conclusive paleontologic evidence for the middle Claiborne age of the Santee limestone is the presence in it of well-developed specimens of Ostrea sellaeformz's Conrad. According to Stenzel (1949) this speciesds restricted to beds of middle Claiborne age, i. e., of the age of the Cook Mountain formation of Texas. This agrees with MacNeil’s observations in Mississippi, Alabama, and Georgia, where shells of 0. sellaeformz's have not been found in beds younger than Cook Mountain except as badly worn and obviously reworked specimens. The middle Claiborne age of the Santee limestone is indicated also by the occurrence in it of Uhlmys waxw- tubbeana (Dall), a species elsewhere restricted (so far as is known) to that horizon, and by several unnamed species that seem to have the same range. The commonly accepted type exposure of the Santee limestone is Eutaw Springs, in Orangeburg County, 31/2 miles east-northeast of Eutawville. Backwater from Lake Marion has partly inundated the old ex- posure, but some limestone still stands above the level of the reservoir. Among species recently taken are Ostrea sellaefomis and E urhodz'a ravenelz' (Twitchell). The best collecting from the Santee limestone is at the spoil bank of the New Santee—Cooper Diversion Canal near Eadytown, at the crossing of Route 45. Caution should be used in interpreting the collections, for perhaps the Castle Hayne limestone overlies the Santee limestone in that region. The Santee fauna from this locality has been studied by Harbison (1944). The following species were collected by the present writers near Route 45 in 1950 and 1951: Fossils frOm the Santee-Cooper Diversion Canal Mollusca: Turritella sp. aff. T. wechesens‘z‘s Bowles prmea. sp. Conns sp. Ostrea sellaeformis Conrad. O. carolinensis Conrad 0. n. sp. aft. 0. podagn‘na Dall Chlamys wautabbeam (Dall) C’. n. sp. aft. 0. membranosa (Morton) 0'. sp. aff. 0. clarkeana (Aldrich) Plicatula fllamentosa Conrad. Spondylus sp. Venem'cardia sp. aff. V. alticostata (Conrad) Grassatatella n. sp. aft. 0. temana (Heilprin) but with an obtuse posterior ridge Lirodiscus santeensis Harbison Pitar (Oostaoalh'sta) sp. Solen sp. cf. 8'. lisbonensis Aldrich TERTIARY STRATIGRAPHY or SOUTH CAROLINA 25 Echinoidea: Otdaris sp. Ooeloplenrns tnfulatns (Morton) Protoscutclla conmdt (Cotteau) Casstdulns gregoryt (Twitchell) ? Euv'hodia raveneli (Twitchell) Besides the species listed above, all of which are be— lieved to have been derived from the Santee limestone, one specimen of Ostrea tm’gonalz‘s Conrad was found. This probably came from a higher horizon, for there are blocks of a harder limestone that apparently does not contain 0. sellaeformis. CASTLE HAYNE LIME STONE The Castle Hayne limestone, heretofore known only from North Carolina, was named by Miller (1910, 1912) from a town in New Hanover County, N. C. The formation has since been described by Kellum ( 1926) and by Richards (1950). It was referred to the upper Eocene by Miller, and subsequent writers have ' correlated it with the Jackson group. Canu and Bassler (1920), who described a large fauna of Bryozoa from Wilmington, specified the age as “middle J ack- sonian.” The echinoids, mollusks, and branchiopods from the Castle Hayne limestone were studied by Kellum (1926) . Their evidence seemed to confirm the Jackson age, though Kellum says that “The poor state of preserva- tion of most of the fossils, together with the relatively large number of new forms and the long range of some of the species, greatly limits their value in correlation.” With the greater knowledge of the range of some species since acquired, it seems evident that most of the fossils attributed by Kellum to the Castle Hayne are some- what older than he supposed, and that the Castle Hayne as here restricted is of late Claiborne age, equivalent to the Gosport sand of Alabama as now restricted.1 Among the species supposed to indicate the Jackson age were Periarchu‘e Zyellz' (Conrad), Ostrea georgiam Conrad (=0. gigantissz‘ma Finch), Ostrea Mgonalz's Conrad, Chlamys deshayesz'z' (Lea) and Onassatella' alta Conrad. Of these only Ostrea gigantissz'ma is now re- garded as exclusively Jackson, and Kellum reports it only from Pollocksville, where its only associate is Ostrea trigonalz's, also commonly Jackson. The speci- mens identified as Chlamys deshayesiz' apparently rep- resent a different, probably ancestral species. The other fossils occur also in the restricted Gosport sand. and Onassatella altar. seems to be confined to it. 1 In 1939 Cooke supposed that the Gosport sand was of basal Jackson age, part of his evidence being the occurrence in it of Periorchus lyelli (Conrad) and Ostrea trigonolta Conrad, species then considered as good indicators of Jackson age. The base of the Jackson at Claiborne, Ala- bama, is now drawn below the Chlamys deshayesl/t (Lea) bed, which was originally included as the top bed in the “Claiborne sand” (Gosport sand). The fossils from Wilmington, Castle Hayne, and sev- eral other places listed by Kellum (1926, p. 11) include a few species that indicate the presence of middle Clai- borne beds as well as the Castle Hayne limestone. Among these Species are E nrhodz'a raveneli (Twitchell) , probably Hemipatagus subrostmtus Clark, and Ostrea sellaefomis Conrad. The middle Claiborne beds evi- dently include the coarse phosphatic basal conglomer- ate that lies on the Cretaceous at Wilmington and Castle Hayne and probably also several feet of lime- stone coquina that overlies the conglomerate. The name Santee limestone might appropriately be extended to these beds. The following section near Wilmington is based on a description and a diagram in the field notes of L. W. Stephenson, 1909. The locality is no longer accessible. The age assignments are by the present writers. The thicknesses are all approximate. Section in the county rock quarry near Wilmington Pleistocene ? Feet 7. Fine to medium-grained loose yellow sand. About___; _______________________________ 8 Miocene Duplin marl? 6. Thin remnants of a sandy shell bed__.____,__ 0—1 Eocene Castle Hayne limestone 5. Irregular masses of hard, massive limestone penetrated by solution channels; highly fossiliferous, containing abundant Terebrar- tula, Porter-chug lyelli, several other spe- cies of echinoids, many bryozoans ________ 10—12 4. Very soft granular limestone with an abun- dance of bryozoans, Terebmtula. The up- per surface is uneven ____________________ Santee limestone? 3. Hard bluish limestone with small dark phos- phatic specks. Evidently formed as a co- quina, as cross-bedding is evident in places- 2 2. Stratified and cross-bedded coquina limestone, partly indurated; ledge at base similar to overlying bed. Contains bryozoans, small pelecypods, and other fossils ______________ 8 1. Phosphatic conglomerate consisting of dark- green nodules in a matrix of gray calcareous sand, all very hard _______________________ 3 In South Carolina the Castle Hayne limestone has been recognized only in artificial exposures. The deep pit of the Carolina Cement & Lime Company 2 miles north of Harleyville, Dorchester County, when exam- ined in June 1951, showed the following sequence: Section at the Carolina Cement ct Lime Company Pleistocene Feet Wicomico formation? 7. Dirty, clayey, sandy soil ____________________ 3 6. Mottled gray and red clay, weathered at top-- 3 5. Subangular gravel containing pebbles as much as % inch in diameter at base ____________ 5 26 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 Unconformity Miocene? 4. Fine angular yellow sand containing black grains and some glauconite ______________ 8 Oligocene ('3) ' Cooper marl. 3. Pale greenish-gray granular marl, glauconitic throughout and containing phosphatic nod- ules at the base; Foraminifera and Chlamys cocoana (Dall) abundant ________________ 3—8 Unconformity Eocene Castle Hayne limestone. 2. Buff-gray, tough to hard, crumbly limestone; Chlamys cookei (Kellum) throughout; Chlamys n. sp. and Glycymeris staminew Conrad in upper part; Chlamys n. sp. aft. 0. deshayesii (Lea), Ostrea trigonalis Conrad, and Periarchus lyelli (Conrad) in lower Feet part ____________________________________ 18 1. Gray soft, fine-grained, granular limestone to bottom of pit; Chlamys cookei and Periar- chus lyelli ___;____ 28 In addition to the species listed in the section, which were all found in place, the following species were col- lected from loose blocks of limestone, which apparently came from bed 2: Endopachg/s sp., Turritella sp. cf. T. amm'cola Conrad, Miltha sp. aft. M. claibomensis Conrad, Crassatella alta Conrad, Lucina sp. cf. L. pan- data Conrad, a large F usinusfi’, a C’ardi'mn, and a Panope. . Of the identified species in beds 1 and 2 all but Gly- cg/mem's staminea are listed by Kellum from the Castle Hayne limestone in North Carolina, and that species is a Gosport form. A sample from the lower part of bed 2 yielded the following species of Foraminifera: Foraminifem from, the Castle Hayne limestone at the Carolina. Cement d5 Lime Company pit (Identified by M. R. Todd) Spiroplectammina wilcowensis Cushman and Ponton‘.’ Textulam‘a recta Onshman Globulina sp. Entosolenia sp. Bolivina sp. Reuseella sp. Angulogerina byramensis (Cushman) var. Valvulin eria n. sp. (cf. V. craSsisepta Keijzer) Gyroidimt soldam‘i octocamerata Cushman and G. D. Hanna Eponides sp. 1 E. sp. 2 Alabamina wilcomensis Toulmin Cibicides danm‘llensis Howe and Wallace 0. lobatulus (Walker and Jacob) C'. plane-conveams Cushman and Todd A rock pit in Orangeburg County nearly 3 miles north of the cement plant also entered the Castle Hayne lime- stone, and is apparently bed 1 of the above section. The pit, which is now full of water, is about half a mile west of Four Holes Station and 3 miles south- southwest of Holly Hill. Periarchus lyelli and Chlamys cookei were found there. DEPOSITS OF JACKSON AGE The formations of Jackson age listed by Cooke in 1936 included the Santee limestone, the Cooper marl, and the Barnwell sand. It has been shown that the Santee limestone is of middle Claiborne age, some beds mapped as Barnwell are of early Claiborne (Congaree) age, and others are of middle Miocene (Hawthorn) age. The Cooper marl is probably of early Oligocene (Red Bluff) age. A small part of the supposed Barn- well remains as the only true representative of the Jackson among the outcropping formations. It is pos- sible, however, that the Ocala limestone or its equivalent is present under cover as the offshore representative of the Barnwell. This is suggested by the occurrence of Ostrea podagrz'na Dall, an Ocala species, at Givhans Bridge (Cooke, 1936, p. 86) . BARNWELL FORMATION On the Savannah River at Shell Bluff, in Burke County, Georgia, and extending downstream to Griflins Landing, the Barnwell formation consists chiefly of a 30-foot bed of large shells of Ostrea gigantissima Finch embedded in pebbly sand and yellowish marl or hard calcareous clay containing Bryozoa (Cooke and Shearer, 1918, p. 61). A few occurrences of this oyster bed have been noted in South Carolina. Sloan (1908, p. 268) reported it along Lower Three Runs on the farm of J. W. Ussery, which is probably a mile or more below the Allendale-Barnwell County line. A well at Bal- dock passed through an oyster bed, perhaps of this same species, about 30 feet below the level of Miller Creek at Baldock (Cooke, 1936, p. 89). However, this oyster bed may have been composed of Ostrea sellae- formis and hence may be part of the underlying McBean formation. A small outcrop of cream—colored very sandy, cal- careous marl in the bed of Miller Creek at an old dam below the water tank at Baldock is probably Barnwell, though it was referred to the Cooper marl by Cooke (1936, p. 88). Such a marl would leach to a massive red sand considered characteristic of the Barnwell, and very common in Burke County, Georgia, notably around Louisville. Canu and Bassler (1920) list 38 species of Bryozoa from this marl at Baldock. None of these species are restricted elsewhere to the Santee limestone, though nine ranged from a higher horizon down to it. One is known only from the Castle Hayne at Wilming- ton, and 21 species occur there. Nine are restricted to TERTIARY STRATIGRAPHY or SOUTH CAROLINA 27 the Ocala limestone, and 27 are listed from it. Seven were found only at Baldock. The evidence of the Bryozoa indicates that the marl at Baldock is of late Eocene (Ocala) age. The marl at Baldock is very rich in Foraminifera. The following species have been identified: Forami/nifem from Eocene marl at Baldoclc (Identified by M. R. Todd) Spiroplectammina mississippiensis alabamensis (Cushman) Temtulan‘a adalta Cushman T. subhauerii Cushman Gaudryina sp. Massilina decorate Cushman Robulus sp. Planulam'a georgiana Cushman and Herrick N odosam‘a latejugata carolinensis Cushman Lagena costata (Williamson) Guttulina byramensis Cushman Globuh‘na gibba punctata d’Orblgny G. sp. Sigmorphma jacksonensis (Cushman) S. sp. cf. S. undulosa (Terquem) S. sp. Polymorphma advena Gushman N omen inewcavatmn (Cushman and Applin) Entosolenia orbigm/ana flintii (Cushman) Bolim‘na gardnerae Cushman B. mississippiensis Cush'man B. momm'nvegi Cushman Reuseella eocemz (Cushman) R. sp. UMgem‘na sp. cf. U. cookei Cushman Angulogerma byramemis (Cushman) Discorbis assulata Cushman D. subaraucana Cushman=“D. Herrick” Vahmh‘nem‘a temana Cushman and Ellisor Gyroidina sp. Eponides sp. Siphom‘na jacksonensis Cushman and Applin Amphmtegine sp. of. A. alabamensis Applin and Jordan Alabama/ma sp. Globigen’na sp. G. sp. Hantlcenina alabamensis Cushman (=H longispina of Cushman and Herrick) Anomalma sp. Gibwides sp. cf. 0. amem'canus (Cushman) 0. damrillensis Howe and Wallace 0. lobatulus (Walker and Jacob) O. mississippie'nsis (Cushman) 0. piano-concerns Cushman and Todd According to Miss Todd the following species are not known from beds younger than Eocene: Nodosaria latejugata carolz‘nensz's, Nonion inemca'vatum, Beussella eocena, and Uibicz'des danm'llensis. OLIGOCENE SERIES When Cooke’s report was written the only known representative of the Oligocene series in South Carolina georgiana Cushman and was the Flint River formation, which is represented by residual blocks of fossiliferous chert, of late Oligocene age. It now appears that the Cooper marl, then sup- posed to be late Eocene in age, is really one stage younger, early Oligocene(?), and 1s equivalent to the Red Blufl' formation of Alabama and Mississippi. Oligocene limestone in Screven County, Georgia, and residual cherts derived from it found along the Savan- nah River are still believed to be of late Oligocene age. COOPER MARL The Cooper marl has been shifted back and forth betWeen the Eocene and the Oligocene. Tuomey (1848) and Holmes (1870) called it Eocene, but Dall (1898) referred it to the lower Oligocene, which then in- cluded the Ocala limestone. Stephenson (1914) and Rogers (1914) classified the Cooper as uppermost Eocene or Oligocene. Stephenson (1914, p. 85) cited the supposed occurrence in it of Basilosawms as indi- cating its Eocene age. This occurrence presumably re— ferred to the so- -called Zeuglodon, which Tuomey (1848, p. 166) mentioned as having been found 1n the long, low bluff extending from Greer’s Landing to Middleton Place on the Ashley River. This specimen has since been identified as Agoraphz'us pygmaeus (Muller), an archaic toothed whale. Other related forms in the Cooper marl are Xenorophus sloam’i Kellogg, from Woodstock, and possibly Archaeodelphis patrius Allen. According to Dr. Remington Kellogg (oral communi- cation), these are the most primitive representatives of the toothed whales, and as none have been found else- where in known Eocene deposits, he thinks they are early Oligocene. Higher zones contain less primitive forms. A. more specific indication of early Oligocene age is Oklamys cocoana (Dall). The type of this little pec- ten was supposed to have been found in beds of Jackson age near old Cocoa Post Office, Choctaw, County, Ala- bama, but it bears the same station number as Red Bluff (early Oligocene) fossils from that vicinity and it is similar to them in color, differing in appearance and state of preservation from shells of known Jackson age. Uhlamys cowl/ma is abundant in the Cooper marl at the Carolina Cement & Lime Company pit (see sec- tion, p. 26). The Foraminifera from the Cooper marl at the cement plant were studied by M. R. Todd, who reported that the fauna appears to be of Red Bluff age. This age is suggested primarily by the occurrence of Bolivi- nella rugosa Howe, a Red Bluff species. Bolivi'nella is not known from beds older than Oligocene. The list of species follows: 28 _ SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 Foraminifera from the Cooper marl (bed 3) at the Carolina Cement & Lime Company ‘ (Identified by M. R. Todd) Spiroplectammina mississippiensis (Cushman) S. mississippiensis alabamensis (Cushman) Robulus sp. Margtnulina. oocoaemis Cushman M. sp. Dentah‘na sp. Legend costata (Williamson) Guttuh‘na byramensis (Cushman) Globulma gibba d’Orbigny Nonion amne (Reuss) Bolivinella rugosa Howe Bulimima ovate d’Orbigny Bolivma byramensis Cushman B. costifem Cushman B. gardnerae Cushman B. sp. ‘ Lomostomum sp. Bifarma vicksburgemis (Cushman) Um'gerina yazooensis Cushman Anguwgerma byra/mensis (Cushman) A. byramensis (Cushman) var. Ellipsonodosam‘a cocoaensis (Cushman) Discorbis arcuato-costata Cushman D. subaraucana Cushman D. sp. Gyroidina bymmensis Cushman and Todd? G. sp. Epom'des sp. Siphonma sp. Canon's sp. Globigerma sp. Oibicides sp. cf. 0. choctawensis Cushman and McGlamery O. lobatulus Walker and Jacob 0'. mississippiensis (Cushman) 0. pseudoungerianus (Cushman) Stichocibictdes n. sp. D yocibioides sp. A well-marked erosional contact of the Cooper marl on the Castle Hayne limestone at the cement plant is additional evidence of a time break, though it does not rule out the possibility that the Cooper is Jackson. MIOCENE SERIES HAWTHORN FORMATION A thin series of sandy clay and gravelly sand beds similar to and presumably originally continuous with the Hawthorn formation of Georgia emerges from be- neath cover at the northern margin of the coastal ter- races and overlaps older formations. This facies of the supposed Hawthorn is quite different from the offshore facies, known only from well cuttings and a very few outcrops in Hampton and Colleton Counties, on the basis of which the Hawthorn was first recognized in South Carolina. Detailed mapping will be required to determine the extent of the Hawthorn formation in South Carolina and to distinguish it from similar facies of the Eocene and Cretaceous formations. The formation can gen- erally be recognized by a characteristic mottling of pink or yellow and gray, though these colors are by no means confined to it. An outcrop that can be referred to the Hawthorn with some assurance is in the cut of the At- lantic Coast Line Railroad that extends 1 mile east from the station at Barnwell. Cooke (1936, p. 91) referred this cut to the Barnwell sand, though it was not consid- ered typical of that formation. Cuts along a new spur line extending northwestward from Dunbarton show excellent exposures of the Hawthorn formation. REFERENCES Bowles, Edgar, 1939, Eocene and Paleocene Turritellidae of the Atlantic and Gulf Coastal Plain of North America: Jour. Paleontology, vol. 13, no. 3, pp. 267—336, pls. 31-34. Canu, F., and Bassler, R. S., 1920, North American early Ter- tiary Bryozoa: U. S. Nat. Mus. Bull. 106, 879 pp. Cooke, C. Wythe, 1936, Geology of the Coastal Plain of South Carolina: U. S. Geol. Survey Bull. 867, 196 pp. , 1939a, Equivalence of the Gosport sand to the Moodys marl: Jour. Paleontology, vol. 13, no. 3, pp. 337—340. , 1939b, Geologic map of Georgia [Coastal Plain]. gia Div. Mines, Mining, and Geology. , 1943, Geology of the Coastal Plain of Georgia: U. S. Geol. Survey Bull. 941, 121 pp. [1944]. Cooke, C. Wythe, and Shearer, H. K., 1918, Deposits of Clai- borne and Jackson age in Georgia: U. S. Geol. Survey Prof. Paper 120, pp. 41—81. Dall, William Healey, 1898, A table of the North American Tertiary horizons, correlated with one another and with those of western Europe, with annotations: U. S. Geol. Survey Eighteenth Ann. Rept., pt. 2, pp. 327—328. Gardner, Julia, 1951, Two new guide fossils from the Talla- hatta formation of the Southeastern States: Washington Acad. Sci. J0ur., vol. 41, no. 1, pp. 8—12. Harbison, Anne, 1944, Mollusks from the Eocene Santee lime- stone, South Carolina: Notulae Naturae 143, 12 pp., 4 pls. Holmes, F. S., 1870, Phosphate rocks of South Carolina and the “Great Carolina marl beds.” Charleston, S. 0., 87 pp. Kellum, Lewis B., 1926, Paleontology and stratigraphy of the Castle Hayne and Trent marls in North Carolina: U. S. Geol. Survey Prof. Paper 143, 56 pp. MacNeil, F. Stearns, 1947, Geologic map of the Tertiary and Quaternary formations of Georgia: U. S. Geol. Survey Oil and Gas Invs. Prelim. Map no. 72. Miller, B. L., 1910, Erosion intervals in the Tertiary of North Carolina and Virginia: Geol. Soc. America Bu11., vol. 20, pp. 673—678. , 1912, The Tertiary formations [of North Carolina]: North Carolina Geol. and Econ. Survey, vol. 3, pp. 171—258. Richards, Horace G., 1950, Geology of the Coastal Plain of North Carolina: American Philos. Soc. Trans, 11. ser., vol. 40, pt. 1, 83 pp. Rogers, G. S., 1914, The phosphate deposits of South Carolina: U. S. Geol. Survey Bull. 580, pp. 183—220. \ Geor- TERTIARY STRATIGRAPI-IY OF SOUTH CAROLINA 29 Sloan, Earle, 1907, Geology and mineral resources [of South Carolina]: South Carolina, State Dept. Agriculture . . ., Handbook of South Carolina, pp. 77—145. , 1908, Catalogue of the mineral localities of South Caro- lina: South Carolina Geol. Survey, ser. 4, Bull. 2, 505 pp. Stenzel, H. B., 1949, Successional speciation in paleontology: The case of the oyster of the sellaefomuie stock: Evolution, vol. 3, no. 1, pp. 34—50. Stephenson, L. W., 1914, A'deep well at Charleston, South Carolina: U. S. Geol. Survey Prof. Paper 90, pp. 69—94. Tuomey, Michael, 1848, Report on the geology of South Caro- lina, vi, 293 pp. Columbia, S. C. Veatch, Otto, and Stephenson, L. W., 1911, Preliminary report on the geology of the Coastal Plain of Georgia: Georgia Geol. Survey Bull. 26, 466 pp. Probable Reklaw Age of a ’ Ferruginous Conglomerate in Eastern Texas GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-0 GEOLOGiCAL SCIENCES LIBRARY Probable Reklaw Age of a ‘ Ferruginous Conglomerate in Eastern Texas By LLOYD WILLIAM STEPHENSON SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 31-43 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—C UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1953 UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 50 cents (paper cover) CONTENTS Page Abstract ______________________________________________________________________________________________________ 31 Introduction-_________-____--______________-_-_____________________-_-_____; __________________________________ 31 The gravel and conglomerate ______________________________________________________________________________________ 32 Character _____________________________________________________________________________________________ ,_ _ _ _ 32 Distribution and relationships _______________________________________________________________________________ 32 In Van Zandt County __________________________________________________________________________________ 32 Sections in Wood and Franklin Counties _____ _ _____________________________________________________________ 33 Probable extension into southwest Arkansas _____________________________________________________ .9 __________ 34 South of Van Zandt County _____________________________________________________________________________ 34 Fossils below the conglomerate (Gardner’s report)- ___.___._________._______________._______...____.__L_ _ __ 35 Analysis of the fossil assemblages (Gardner's report) _______________________________________________________ 37 Outcrops of conglomerate east of Tyler basin ______________________________________________________________ 37 List of conglomerate localities ___________________________________________________________________________ 38 Source of quartzitic pebbles and cobbles in the conglomerate ________________________________________________ 40 Significance _______________________________________________________________ -_ _______________________________ 40 References ____________________________________________________________________________________________________ 42 Index______________._-_________-_-________-_______; __________________________________________________________ 42 ILLUSTRATIONS Page Plate 3. Map showing areal distribution of Wilcox and lower part of Claiborne groups and occurrences of quartzitic sand- stone and ferruginous gravel and conglomerate ________________________________________________________ In pocket 4. Specimens and outcrops of ferruginous conglomerate, sand, and sandstone ____________________________ Opposite 34 5. Outcrops of quartzitic sandstone and fossiliferous ferruginous sandstone __________________________________ Opposite 35 III PROBABLE REKLAW AGE OF A FERRUGINOUS CONGLOMERATE IN EASTERN TEXAS By LLOYD WILLIAM STEPHENSON ABSTRACT The suggestion is offered that ferruginous gravel and conglom- crate in eastern Texas, apparently heretofore regarded by geologists as surficial rubble or terrace deposits of Quaternary or Recent age, is a basal bed of the Beklaw member of the Mount Selman formation (Eocene). The bed is composed of fragments of ferruginous sandstone, siderite concretions, and scattered fragments of hard quartzitic sandstone, in a matrix of coarse quartz sand, probably all mainly derived by reworking from the undifferentiated Wilcox group. These components range in form from angular to well water-worn. The cementing mineral 0f the conglomeratic facies 0f the gravel is mainly limonite. The evidence for the Beklaw age of the gravel and conglomerate is afforded by the following facts: The observed outcrops are all on or near the belt of outcrop of the Reklaw member as shown on the geological map of Texas, issued by the United States Geological Survey in 19:57; the bed was ob- served passing under sand beds interpreted to belong to the Reklaw member at two localities; the apparent absence of similar gravels and conglomerates in the belt of outcrop of the Wilcox group where, as surficial rubble or terrace deposits, they would be expected to be present at different levels, may be considered negative evidence; it seems impossible to explain by the action of any Recent or near Recent drainage systems the transportation of coarse quartzitic sandstone clastics of the Wilcox group from their original position, for the distances of 5 to 20 miles to their present position, in gravels and conglo- merates at upland levels. If the ferruginous gravel and conglomerate here described is in fact a basal conglomerate of the Reklaw member from Nevada County, Ark., at least to Wilcox County, Tex, the merits of the uncouformity thus indicated versus the unconformity reputed to be present at the base of the Carrizo sand, should be critically reviewed to determine which one should be accepted as marking the base of the Claiborne group. The need for a V thorough restudy 0f the Wilcox-Claiborne relationships in cen- tral and northeastern Texas and in southwestern Arkansas is stressed. INTRODUCTION The facts presented and the suggestions offered in this paper are based mainly on field observations made in central and northeastern Texas and in southwestern Arkansas during the autumn of 1942 and the spring of 1943. The immediate purpose of the investigations was a search for additional reserves of aluminum ore (baux— ite) in the sediments of the Wilcox group (early Eo— cene). Marc Miller, field assistant, United States Geological Survey, accompanied me in 1942 in Texas, and Watson H. Monroe, geologist, United States Geo- logical Survey, spent several days with us in the field. In May 1951, in company with Joe Lang, ground-water engineer, United States Geological Survey, I examined several additional localities near Floresville, Wilson 218545—53 County, and in eastern Caldwell County. No impor— tant deposits of bauxite ore were discovered, but certain facts were recorded which may have bearing on the stratigraphic relations of the \Vilcox and overlying earlier Claiborne sediments of the area. As shown on the geologic map of Texas, issued in 1937 by the United States Geological Survey, the \Vilcox and lower Claiborne section in northeastern Texas in— cl udes the Wilcox group (undifferentiated) , unconform— ably overlain by the Carrizo sand of the Claiborne group, overlain in turn by the Mount Selman formation (Claiborne). Plate 3 of the present paper is essentially a copy (reduced one half) of part of the Texas map, showing the Wilcox and lower Claiborne section, ex- cept in Leon County where the boundary lines are based on the geologic map accompanying Stenzel’s report (1939) on that county. I was not able in the time at my disposal to make a thorough study of the beds immediately underlying the Rcklaw member of the Mount Selman formation in northeast Texas. However, as indicated on the follow- ing pages, occasional exposures showed that the beds below the Reklaw are mainly irregularly bedded, fine to medium, light—colored sands, sandy clays, lenses of white clay, and interbedded carbonaceous clays and lignites. N0 sands approaching in coarseness the more typical Carrizo sand, and no exceptionally thick beds of sand, were observed. The Carrizo is mapped as a narrow band in northeast Texas and if present should be relatively thin. However, there seemed to be no satisfactory basis at the time for distinguishing repre- sentatives of the Carrizo sand from the underlying Wilcox group west and northwest of the Tyler basin and north of an undertermined point along the strike of the formations, possibly in Robertson County. ‘How- ever, the Carrizo has been identified in this area by other geologists, and it may be represented by a thin section of sands and clays above the undifferentiated Wilcox group. During the investigations many outcrops of an in- durated ferruginous facies of gravel were observed and recorded on or near the belt of outcrop of the Carrizo and Recklaw units, as this belt is shown on the ac— companying geologic map (pl. 3), which is essentially a copy on a reduced scale of the part of the previously cited geologic map of Texas showing these units. How- ever, corrections were made in Leon County, following Stenzel’s geologic map of that area (1939, in pocket), 31 32 PROBABLE REKLAW AGE OF A FERRUGINOUS CONGLOMERATE IN TEXAS and, with Murray and Thomas’ small-scale map as au- thority (1945, p. 48), an approximate boundary of the Paleocene and Wilcox group was added in the Sabine uplift area. The conglomerate is usually present as cappings on low hills and ridges which have been pro- tected from erosion by the resistant character of this rock. The unindurated gravel was either removed by erosion or, if present, was generally not conspicuously exposed in its down dip extension in the smooth surfaces intervening betheen the hills and ridges. The con- glomerate was traced from Van Zandt County to the northeast and east through Texas and far into Arkan- sas; from the same county it was traced to the southWest as far as lVilson County. Exposed sections showing the character of the materials above the gravel or conglomerate, as the case may be, are rare, but where they do occur they seem to afiord satisfactory evidence that the gravel bed indeed marks the base of the Rekl aw (see sections, pp. 33, 34) . THE GRAVEL AND CONGLOMERATE CHARACTER The lithologic character of the gravel bed has not been studied critically. Macroscopically it appears to be composed mainly of fragments of ferruginous sand— stone, oxidized pebbles derived from siderite concre— tions, in a matrix of coarse, poorly sorted quartz sand. Scattered through the gravel are pebbles, cobbles, and even boulders as much as 1 foot or more in length, of hard. fine-grained quartzitic sandstone derived from rock of this kind known to be present in place in the Wilcox group (see pl. 4). These components range in form from angular through subangular to well- rounded; even‘the quartzitic sandstone pebbles may be completely rounded (pl. 4A). At given outcrops the quartzitic sandstone clastics may be rare, plentiful, or very abundant. The coarser of these components, and even much of the sand matrix, are believed to have been derived mainly from the clastics of the Wilcox group, but in part from the Carrizo sand where that unit is present above the Wilcox. The cementing material of the indurated gravel (conglomerate) is iron oxide, usually in the form of limonite. DISTRIBUTION AND RELATIONSHIPS IN VAN ZANDT COUNTY The gravel bed was first observed poorly exposed in a ditch of the old Grand Saline-Canton road and in an adjoining field, about 7.7 miles southwest of Grand Saline, 1.4 miles southwest of Clark School, 1.15 miles northwest of Star Church, Van Zandt County (see soil and road maps of the county), 4.5 miles northeast of Canton. Here the gravel bed crops out on a slope about 10 ft below the crest of a low ridge; it is very cearse, the pebbles, cobbles, and even boulders consisting mainly of more or less water-worn, very hard, fine-grained, quartzitic sandstone, as much as 1 ft in length, but in part of oxidized siderite concretions and fragments of ferruginous sandstone. No quartz pebbles were seen. Many of the quartzitic pebbles, cobbles, and boulders bear the fossil impressions of roots and rootlets. As was later determined, the source of these quartzitic clastics is large masses of this kind of rock in place in the undifferentiated Wilcox group 8 or 9 miles to the west in Van Zandt County. Four-tenths to 0.8 mile southeast of the gravel out— crop just described, and 0.3 to 0.7 mile northwest of Star Church, a similar gravel bed, about a foot thick, indurated in part to ferruginous conglomerate, crops out near the crests of two low hills and is closely asso- ciated with impure pisolitic bauxite materials, samples of which were assembled for study in the laboratory of the United States Geological Survey. The pisolitic structure is present in the conglomerate and in clay underlying the conglomerate. On the geological map of Texas (1937) the two hills bearing the conglomerate and associated bauxitic materials appear to be mapped as an outlier of Carrizo sand. If beds of Carrizo age are present in these hills they would have to be repre- sented by poorly exposed, nontypical, relatively fine, more or less silty, light—colored sands and interbedded clays which underlie the conglomerate. The necessarily brief field study made at the time did not yield satis— factory data for discriminating these light—colored sands and clays from the undifferentiated Wilcox group, nor for considering them as representing the Carrizo sand in this part of Texas. According to Wendlandt and Knebel (1929, pp. 1350, 1351) and Stenzel (1951, pp. 1818—1822), the Carrizo sand is present in north- eastern Texas and is separated from the underlying Wilcox group by a pronounced stratigraphic break. The relationship of the gravel to underlying beds is not clearly seen in the hills northwest of Star Church, but a better section is afforded by an exposure in a road ditch on the northeast facing slope of the valley of Little Sa- line Creek 3.5 miles southeast of Star Church, 1.2 miles east of Oakland School, 7.4 miles northeast of Canton. Section in road ditch 1.2 miles east of Oakland School, Vim Zandt County, Tow. Mount Selman formation: Reklaw (‘2) member: Feet Sand and clay, weathered _____________________ 5 Sand and gravel, irregularly bedded, loosely cemented to sandstone and conglomerate; pebbles are mainly ferruginous sandstone and oxidized siderite in a matrix of coarse sand; several pieces of silicified wood and one loose pebble of quartzitic sandstone were observed__ Unconformity (undulating, sharp contact). Cl ~ Pre-Reklaw beds : Sand and more or less sandy clay, rather evenly bedded, light-gray, stained to reddish and pink- ish tints in upper 10 to 15 ft _______________ 25 35 THE GRAVEL AND CONGLOMERATE 33 The gravel at this locality is similar to that at the localities northwest of Star Church, but lacks abundant pebbles and cobbles of quartzitic sandstone and does not display bauxitic structure. The gravel is 35 or 40 ft lower (aneroid determination) than the gravel on the hills northwest of Star Church, its lower position probably being due to a low regional dip to the east or southeast. At a locality near Saline Creek, 23 miles northwest of the preceding, 1.1 miles east of Star Church, a read out reveals 16 ft of thinly stratified fine greenish-gray slightly glauconitic sand, with interlaminated soft thin flaky ironstones; about 4 ft below the top is an irregu- lar layer of concretionary ironstone. This is a fairly typical section of the Reklaw member of the Mount Selman formation, as developed west of the Tyler basin in northeastern Texas. The road cut was not deep enough by several feet to reveal the base of the Reklaw. Because of a broad structural uplift, the Van uplift in eastern Van Zandt County, the beds forming the up- per part of the Wilcox group are nearly flat-lying and immediately underlie the surface in an extensive area north of Neches River. The beds of the Rekl aw mem- ber of the Mount Selman formation and the Carrizo sand (if present) have been removed by erosion from most of this area, but here and there indurated parts of the gravel bed have resisted erosion and formed low hills capped with ferruginous conglomerate. At such places the higher beds of the Reklaw, presumably once present above the conglomerate, have been removed by erosion. These outliers, with the exception of the one northwest of Star Church and one 5 miles southwest of Grand Saline which are mapped as Carrizo sand, are not shown on the geological map (1937) . The lecations of several of the unmapped outliers are indicated in the list given on page 39. The main belt of outcrop of the Reklaw member swings eastward around the nose of the Van uplift, extending from the vicinity of Martins Mills in south-central Van Zandt County, eastward to Neches River near the Smith County line, thence northward near the county line to the vicinity of Silver Lake in northeastern Van Zandt County. Several occurrences of the conglomerate were observed on or near this Car- rizo and Reklaw belt as shown on the geological map (see pl. 3). SECTIONS IN WOOD AND FRANKLIN COUNTIES An exposure in a road ditch shows the character of the main body of the Reklaw in northeast Texas and is described below. The ditch does not cut deep enough to reveal the base of the member. The conglomerate was seen, however, near the crest of the east—facing slope of Cottonwood Creek, about 2 miles west of Golden. Section in cut of U. S. Highway 6.9, 0.75 milc northwest of Golden, Wood County, Tax. Mount Selman formation: Reklaw member: Clay and sand, thinly laminated, light—colored, with interbedded flakes of ferruginous sand- stone; weathered in upper part ____________ __ 6 Clay, sandy, thinly laminated, dark-gray, inter- bedded with fine sand, with many interbedded thin flakes of ferruginous sandstone; small filled borings give to it a peculiar spotted ap—‘ pearance; at the base is a very irregular layer of ferruginous, micaceous sandstone 2 to 10 in. thick ___________________________________ 6 Sand, massive, light-greenish—gray, with many filled borings; filmy clay is scattered through the sand in fine detail ______________________ 7 Feet 19 The thin filmy flakes of ferruginous sandstone men— tioned in the preceding section appear to be character— istic of the main body of the Reklaw member in north- eastern Texas west and northwest of the Tyler basin. The section described below, if correctly interpreted, shows 25 ft of sand of the Reklaw member, underlain by 4 ft of basal coarse ferruginous sand and gravel, underlain in turn by 8 ft of pre—Reklaw sand and clay. Section in road ditch near fork 5.25 miles north-northeast of Quitman, 2 miles north of Forest Hill School, 0.3 mile north- east of Clover Hill Baptist Church, Wood County, Tear. Mount Selman formation : Reklaw member: 'Feet Sand, compact, fine, partly weathered, with scat- tered small flakes and films of ferruginous sandstone __________________________________ 5 Sand, fine, ferruginous, weathered ______________ 20 Sandstone, ferruginous, medium to coarse, irregu- larly bedded, and coarse conglomerate, with some reworked clay balls and a few pebbles of quartzitic sandstone ________________________ 4 Unconformity. Pre—Reklaw beds : Sand and clay more or less weathered, light-colored, irregularly bedded, medium to coarse, in part ar- kosic __________________________________________ 8 37 Another section which shows ferruginous gravel and conglomerate beneath 25 ft of sand of the Reklaw member is exposed near Scroggins in Franklin County. 34 PROBABLE REKLAW AGE OF A FERRUGINOUS CONGLOMERATE IN TEXAS Section in ditch of north-south road, south-facing slope of Dry Cypress Creek Valley, 0.25 mile northwest of Soroggins, Frank- lin 001m ty, Tom. Mount Selman formation: Reklaw member : Sand, mostly massive, fine, in part argillaceous, gray, mottled with pink and yellow, weath- ered in upper part __________________________ Sand and gravel, irregularly bedded, in part indurated to conglomerate; observed one piece of quartzitic sandstone in the conglom- erate and three loose pieces of quartzitic sandstone ________________________________ 2 t0 4 Unconformity (undulating). Pre-Reklaw beds: Sand, light-gray, irregularly bedded, mostly loose, with minor clay layers and lenses ______________ 18 Feet b: C?! Outcrops of the gravel and conglomerate are par— ticularly abundant in the vicinity of Scroggins, their distribution over a north—south belt about 6 miles wide probably indicating a decided flattening of the Reklaw beds in this area. The relationships of the beds in the two preceding sections seems to show that the gravel bed passes under fine sand referable to the Reklaw member. PROBABLE EXTENSION INTO SOUTHWESTERN ARKANSAS Occurrences of ferruginous conglomerate on or near the belt of outcrop of the Reklaw member of the Mount Selman formation (as mapped) between Franklin County and the Arkansas line are listed on pages 38—39. Beyond the Arkansas line outcrops of ferruginous con— glomerate, usually containing pebbles and cobbles of quartzitic sandstone with impressions of rootlets, and in all respects like the gravels and conglomerates already described in Texas, were observed in Nevada County, Ark, southwest and northwest of Bodcaw, southwest of Mt. Moriah, east of Lanesburg, and north of Cale. They all occur in an area mapped as Wilcox formation (geologic map of Arkansas, 1929). They are in a belt trending from southwest to northeast obliquely across the strike of the Wilcox formation (as mapped), the stratigraphic position of the ones farthest to the north— east, east of Lanesburg, probably being less'than 60 ft above the top of the Midway formation. If it is as- sumed that the conglomerate is correctly correlated with a basal conglomerate of the Reklaw, an overlap of the Claiborne group across the Wilcox group is indicated. It is appropriate here to direct attention to a bed of impure bauxite in the southwest corner, sec. 32, T. 9 S., R. 19 “7., 5 miles east of Gurdon, Clark County; in— durated ferruginous portions of this bauxite strongly resemble the impure bauxite in the low hills northeast of Star Church, Van Zandt County, TeX. (pp. 32, 33), which suggests the possibility of their being at the same stratigraphic position. A few quartz pebbles were seen in the conglomerate in Arkansas. Between the Texas-Arkansas line and Nevada County, Ark, the Eocene formations are largely covered with surficial Pleistocene and Recent deposits of the Red River and its tributaries, and in this gap no outcrops of conglomerate resembling the basal part of the Reklaw were observed. SOUTH OF VAN ZANDT COUNTY, TEXAS In Robertson and Milam Counties, Tex., several out— crops of light-colored sand, usually associated with more or less light-colored clay, were seen below the ferrugi- nous conglomerate; these sands, in part moderately coarse, were not nearly so coarse as much of the typical Carrizo sand which, however, they may represent. A sand section that may represent the Carrizo is exposed in a clifl' overlooking Little River Valley, north-north- east of Gause, Milam County. Section in a cliff 2.9 miles north-northeast of Game, Milam County, Tex. Mount Selman formation: Reklaw (‘2) member: Sandstone, ferruginous, with a band of basal conglomerate made up of pebbles of ferruginous sandstone, oxidized siderite, and quartzitic sandstone ____________________________________ 10 (‘arrizo ('2) sand: Sand, in part massive, in part laminated, with subordinate light-colored clay laminae, and Feel. with several indurated ferruginous bands _____ 40 Sandstone, massive, light-gray, rather soft _____ 30 Sand, poorly exposed, mostly unconsolidated, more or less laminated, more or less argillaceous __________________________________ 40 Concealed to base of slope ______________________________ 20 140 The observed occurrences of the conglomerate in northeastern Texas west and north of the Tyler basin are all on or near the narrow belts of outcrop of the relatively thin “Carrizo” sand and Reklaw member of the Mount Selman formation (as mapped). This is true as far south as Lee County. In this direction the first evidence of the more typical sand of the Carrizo was observed 4.5 miles northwest of Tanglewood, Lee County, where fragments of very coarse, ferruginous sandstone were observed scattered about on the top and slopes of a low ridge. From this place southwestward the true Carrizo unit thickens and its belt of outcrop gradually widens to a maximum of about 10 miles in Atascosa County. Gravel, usually indurated to ferruginous conglom- erate, was observed here and there from the vicinity of Tanglewood in Lee County (pl. 4A, D), through Bas- trop, Caldwell, and Gonzales Counties, as far west as a point 4 miles northwest of Floresville, Wilson County. Wherever seen, these outcrops occur on either the .5550 ooA auo05>01w€m9 «0 $9,255: mama m 300? emu? a no fin vaaéxou E 5de§®- mo flag Emacs oawnofiofimqou was wzog‘wcsdm msofiwsbfl mo momma: .Q (3::00 $4895 ”Edged we vmco $95338 Hm «w kdBAwflw .w .D no ado E .833wa go 953 Emacs opdpofioflmnco g5 95% msoiwsiow @9353 35.33%: .0 .3550 occumwwym .30:an noqvm Sam mo 36 «o 55: 2:: mmd chamomwo 8%de 6. 50¢ 3E2:2w:0o msosmwfifitfl Ewan .m .Qsohw x82? 05 59¢ UQZSU vHHoPmcndm oEEfimsv Mo 0385 vvcasgiok a $639: 33550 00% £095onqu Mo $9,585: 3:5 m .oagofiofiwco‘e 23 fits U958 wwci a :5: 352:2wzoo wsoimziow Emhmm .vx mZOHwQZ39 5.5: 328 w 94020 mmwaom we View £50m. .QBdEom “o is; Emma: opEwEEMQQQ mso:_m=E3 RE Edigo Amcaoomv wagnvasm mzozmwsifl machwtmmmoh .m J14 £3500 $52 szdimxofi mo $6235: 3:5 *4“ .qudESw M825, 0% E fig ENE a E k52%ther poop 5E acopwwcww uwfiNinSU BEE 25 mo wmdz AN mZOrerZflDw Q¢O~UOQOHU 5 THE GRAVEL AND CONGLOMERATE ' 35 western edge of the Reklaw belt or the eastern edge of the Carrizo belt (as mapped), their distribution along this restricted area tending to confirm their position as basal gravel of the Reklaw member. Here as farther north, pebbles of quartzitic sandstone from the Wilcox group are common in the conglomerate, even in its most westerly observed occurrence northwest of Floresville. From Bastrop County southwestward through Cald- well, Gonzales, Guadalupe, and Wilson Counties, the outcrop area of the Carrizo sand is a thinly inhabited belt underlain by beds of sand, many of which are con- spicuously very coarse. These sands form a relatively low, broad ridge characterized by infertile soils and supporting a cover of blackjack oaks and other sandhill vegetation. The alinement of the occurrences of the ferruginous conglomerate east of this belt along or near the western edge of the belt of outcrop of the Reklaw member seems significant. The main body of the Carrizo sand lacks marine fos- sils, and its irregularly bedded sands, in part conspicu- ously coarse, suggest continental origin on a low coastal plain bordering the Eocene sea. There is evidence, how- ever, that toward the end of the deposition of this sand body the sea advanced over its southeastern and southern edge along a coastline extending from Bastrop County through parts of Caldwell, Gonzales, and Wilson Coun- ties, at least as far west as the vicinity of Leming in Atascosa County. In this shallow sea was deposited a relatively thin unit of ferruginous sand now bearing the imprints, and in places the undissolved shells, of marine fossils. The position of at least the lower part of this sand below the ferruginous conglomerate is shown by a section on the south fork of Scruggs Creek, described below. (See pl. 53.) The geographic position of this fossiliferous sand shows that it must immediately over- lie the main body of the Carrizo sand. Section on south fork of Scruggs Creek just west of a north- south road, I, miles north by east of Harwood (Gonzales Goun- tll). in Caldwell County, Tear. Mount Selman formation: Reklaw ? member: Conglomerate, coarse, ferruginous, composed mainly of fragments of ferruginous sandstone and oxidized siderite concretions, but including pebbles of chert fro . the Edwards limestone and a few pebbles and cobbles derived from Wilcox quartziti< sandstone __________________ 1 Unclassified beds (Bigford?) : Feet Clay, red, ferruginous. weathered __________________ 2 Sandstone, ferruginous--- _______________________ 3 Sandstone, rather soft, thin to moderately thick- bedded, somewhat irregularly bedded, ferrugi- nous, micaceous, with fossil imprints in the lower3or4ft-_.--- ________________________ 9 15 218545—53—2 FOSSILS BELOW THE CONGLOMERATE (GARDNER’S REPORT) The fossils collected from the section on Scruggs Creek have been identified and listed by Julia Gardner of the United States Geological Survey, whose report is quoted as follows: Locality (2 collections) 18158 and 18187. South fork of Scruggs Creek near crossing of north-south road, 10.5 miles east- northeast of Luling, 4 miles northeast of Harwood (Gonzales County), in Caldwell County, Tex. (See road map of. Cald- well County.) Collected by L. W. Stephenson and Marc Miller, December 3, 1942; Stephenson and Joe Lang, May 12, 1951. Nuculanid, possibly a very large Sacella; similar to molds from localities 12468 and 12469. Nuculanid cf. Adrana aldrichlana Harris from locality 12535. Ostreu sp. M odlolus sp. Venerz‘cardta sp.; of moderate dimensions, more than" usually convex, numerous ribs; common, and similar to those from locality 12535. Diplodouta? sp., small, interior only; possibly Abra rather than D’lplodonta. “Cardlum” sp. s. 1. Venerid? “Tellina” sp. s. 1. cf. T. talllchett Harris. Ensis? sp. Splsula? sp.; small, trigonal, posteriorly rostrate; very abun- dant; cf. locality 12535. Corbula sp. cf. 0. smithvtllensts Harris and 0. gregortot Dali. Cadulus? sp. Turritella? sp.; whorls large, finely sculptured spirally, strongly keeled about one—third of the distance back from the anterior suture. Mold resembling a naticoid but with a varicose outer lip. Ectluochtlus? sp.; common, and similar to forms from locality 12535. Distorslo? sp.; only a single mold. Several indeterminate gastropod molds. Volutocorbls sp., possibly several species; common; includes V. sp. cf. V. ltsbonensts Aldrich. Fragment of nautiloid. The fossils listed are in a matrix of noncalcareous, ferruginous sandstone, flecked with small mica grains and a few clear and very small quartz grains. A yellowish mineral also present, which may be a form of iron oxide distinct from that which gives the brick red color to the rock. Hardness varying from soft granular to very hard. Fossils common but indicated by internal and external molds only. No shell substance preserved. This locality is strikingly similar both lithologically and faun- ally to locality 12535, 2 miles north of String Prarie, Bastrop County, Tex. Gardner lists the fauna from the String Prairie local- ity and discusses the containing matrix as follows: Locality 12535. East bank of Brushy Creek, 2 miles north of String Prairie, Bastrop County, Tex. Nuculanid cf. Adrana aldrichiana Harris. Nuculanid, possibly Sacella. Area sp. cf. Anadara rhomboidella Lea. Area sp. cf. Barbatta ludom’m’ana Harris. Venericardta sp. cf. V. densata Conrad; fairly large for that species, very convex; very abundant. Dlplodonta sp. 36 , PROBABLE REKLAW AGE OF A FERRUGINOUS CONGLOLIERATE IN TEXAS Tell/ma sp. cf. 7'. cherolceensis Harri-s. Tellma sp. s. 1. cf. T. tallicheti Harris. Abra? sp. , Corbula sp. cf. 0. gregarioi Dall. Spisula? sp. ; small, trigonal, posteriorly rostrate ; very abundant. FicOpsis sp. , Ectinochtlus? sp.; very abundant. Pseudcliva sp. Volutocorbt‘s sp.; very abundant. A coherent, noncalcareous ferruginous sandstone, the sand grains a clear quartz, with a red or yellowish red, probably argillaceous, dusty, interstitial filling. Fossils abundant but in the form of molds and impressions. A scattering of very small grains of mica. Gardner reports upon fossils in the National Museum from several other localities along or near the belt of outcrop of the Reklaw between Gonzales and Atascosa Counties, as quoted below. The stratigraphic relation— ships of the containing matrix at these localities to the ferruginous conglomerate were not determined by the collectors. Locality 18183. Three and one-half miles northeast of Harwood, Gonzales County, Tex. Madracis sp. ; by far the most common form. Coral. Nuculanids; mostly Sacella; Admna possibly represented. Ostrea sp., juvenile. Crassatellites? sp. C’mssinella? sp. Venericardia sp. or Cardita sp. Protocardia gambm’na. Dall. Abra? sp. Corbula sp. ; small, high, and numerous, suggesting C. smith- m‘llensis Harris and 0. gregarioi Dall. Corbula sp cf. 0. temana Gabb. Uadulus sp. “Natica” semilunata Lea s. 1. Fragment of shoulder, of gastropod of moderate size. Volutocorbis sp. A calcareous, indurated mixture of ferruginous sand and fragments of shells broken before burial; the shell substance still preserved. No bedding evident or trace of any sediment pattern. Locality 18185. Cemetery ridge at north edge of Belmont, Gon- zales County, Tex. ' Venericardia? sp.; fragments of strong radial sculpture that may possibly be Cardium. Cardiumi’ sp.; a many ribbed form that may be a Cardium of moderate size or Venericardia; no hinges. O'orbula sp. cf. 0’. gregofloi Dall in size and shape. Volutocorbis sp. ; rather coarsely ribbed. An indurated sandstone highly ferruginous and highly fos- siliferous along the well-defined bedding planes: beds about 0.5 in. thick marked by an occasional thin iron oxide crust and a high concentration of small fossils, mostly Corbulas. Fossils occurring only in the form of molds, no shell substance remain- ing. Little or no reaction to acid; surface minutely porous, specked with some light-yellowish mineral, possibly a form of iron oxide. Apparent porosity may be a form of micro-oolitic texture. Very fine flecks of mica and some minute clear grains of quartz. Locality 18186. North edge of Belmont at south edge of ceme— tery, Gonzales County, Tex. Venericardia sp. ; a fragment of sculpture only. Pcriploma? sp. I’m-vilucina sp. Corbula sp. cf. 0. gregarioi Dall. Eosurcula? sp. Lithologic character similar in a general way to that of the matrix at locality 18185 but less indurated; not bedded con- spicuously but with the same apparent porosity or micro-oolitic texture. All fossils in the form of molds only, and. less concentrated. Locality 12468. One-half mile above Willow Springs ranch house on Capote Hill road, Gonzales County, Tex. Nurcula sp. Leda sp., possibly a large Sacella. Arca sp., a single small mold. Venericardia sp.; 0f moderate dimensions, more than usually convex, and having thirty ribs. Lucinoid ; fairly large, and concentrically corded. Diplodonta; mold of interior only. Venerid; decorated with crowded concentric lines; possibly Oytherea. - Ensis 81)., very slender. Corbula sp., possibly n. sp. Simmz? sp. Olit‘ula? sp.; very slender. Volutocorbis sp. Turrids. Levifusus sp. cf. L. trabeatoides Harris. A noncalcareous red sandstone flecked v'vith small mica grains and a few clear [and very small quartz grains. A yellowish mineral also present which may be a form of iron oxide distinct from that which gives the brick-red color to the rock. Fossils common but indicated only by internal and external molds. No shell substance preserved. Locality 12469. Boulders near Toudouze’s ranch house, 3.5 miles north and 1.5 miles eaSt of Leming, Atascosa County, Tex. N uculmza, possibly a Sacella similar to that at locality 12468. Area sp.; fairly small. Venericardm sp.; small, 13/2 to 2 mm in diameter and about thirty ribs. Lucinoid. Venerid. Abra? sp. Corbula sp. cf. 0’. gregarioi Harris; faint posterior radial lineation. Tm-ritella. sp.; very small. Uzita? sp. ‘ Volutocorbis sp. Turritid. Red calcareous quartz sandstone and calcareous concretions, containing possibly a few scattered grains of glauconite. Sand- stone dense and hard to break. Concretions very dense, fine- grained, probably a calcareous clay, seamed with crystalline calcite and embroidered in patterns of dendritic manganese. Shells common and firmly embedded; when an attempt is made to remove them, they often break across the shell or leave the external surface on one fragment and the internal surface on the other. Concretions apparently barren. Locality 12467. One—half mile south of Toudouze’s ranch house, 4 miles northeast of Leming, Atascosa County, Tex. Jladracis sp. Balmmphyllia? sp. Nuculana sp. cf. N. corpulentoides Aldrich. THE GR AVE L Modiolus (Mauricio) sp. cf. M. (M.) houstom’us Harris. Ostrea sp. Venericardia (Venericor) sp.; of moderate dimensions, than usually convex; common. Luci11oid?; closely threaded and of moderate size. Diplodonta sp. Tcllina sp. cf. T. cherokeensis Harris. Mactroid or venerid. Abra? sp. cf. A. nitens Conrad. Venerid. Ensis sp.; similar to E. lisbonensis (Aldrich) but smaller. Corbula sp. cf. 0, deussem‘ Gardner; possibly n. sp. Corbula sp. cf. 0. gregarioi Dal]. Architectonica? sp. ’I‘urm’tella sp. Sinum sp. Nassoid. Buccitriton tea-(mus (Gabb)?; common. Lecifusus sp. Buccinoids. Indeterminate gastropod. Pseudolwa sp. Mitre? sp. Ancilla punctulifcm (Gabb)? Volutocorbis sp. cf. V. lisbonensis (Aldrich). Volutocorbis sp.; probably immature. Cancellam’a? (Trigonostoma) sp. Turrids; probably 3 species. Turrid; cf. Eopleurotoma. Terebra sp. more A noncalcareous ferruginous sandstone similar in appearance and mineral content to that from String Prairie and from 4 miles northeast of Harwood. Apparently, the shell substance is replaced in part by some iron compound; the molds obtain- able from such replacements are sharper than molds formed by leaching only. Locality 12534. Toudouze’s pasture, 0.5 mile west of the ranch house, 4 miles northeast of Leming, Atascosa County, Tex. Coral. Barbatia sp.; a single cancellate form. Vcnerica-rd'ia. (Venem'cor) sp.; similar to those from locality 12467 and also common. Abra sp.; similar to those from locality 12467 but only a single indivdual; of. A. m‘te’ns Conrad. Corbula. sp. cf.; 0. gregarioi Dall. Naticoid. Phos? sp. Levifusus sp. Volutocorbis sp. of. V. lisbonensis (Aldrich). Ancilla sp. cf. A. punctulifem (Gabb). Cancellaria (TrigonostOma) sp. Turrids ; probably 3 species. Eosurcula? sp. Cylichna sp. A very fine-grained sandstone, containing a green mineral, probably glauconite, but little 01' no mica and few or no clay minerals; reacting feebly to acid in areas from which the shell substance has been leached; strongly, of course, if the shell sub- stance is still retained. Very much harder than the sandstone at locality 12467. ANALYSIS OF THE FAUNAL ASSEMBLAGES Gardner discusses the foregoing collections of fossils as follows: AND CONGLOJMERATl-l 37 With the exception of some of the material collected near Toudouze’s ranch house in Atascosa County, the fossils are prey served in the form of interior molds and, less commonly, as exterior molds. Such material offers unsatisfactory grounds for generalization. Among the most abundant species present are a very low, transversely elongated nuculanid and a small Rimella-like form, possibly Ectinochilus, but with a less persistent axial sculpture than that of E. tewtmus (Harris), and apparently distinct from the subspecies planus of Harris. They are recorded only at two localities: one is 4 miles northeast of Harwood (collections 18158 and 18187), and the other 2 miles north of String Prairie (loc. 12535). The two species, the pelecypod and the gastropod, are exceptionally well characterized and conspicuously abundant at these two localities. imperfectly preserved and fragmentary material, but apparently they are undescribed and are unrecorded in the National Museum collections from the Wilcox and lower Claiborne of east central Texas. The general similarity in the lithologic character of the ma- trices from which the fossils here listed hav e been taken makes any theory involving distinct facies seem dubious, but positive evidence is wanting of any age difference between the faunas containing the abundant and probably new species and the other faunas. Only two positively identified species, Protocardia gambm‘na Dall and “Notice” smm‘limam Lee, are listed, and both are from the locality 3.5 miles northeast of Harwood (loc. 18183) ; neither of them is restricted to a limited horizon. But both the component species and the assemblages most closely resemble the forms and faunas of the lower Claiborne, and all are contained in highly colored ferruginous clastics. Forms so abundant as the two species in question must have made their record elsewhere and, when discovered, their new associates may give the missing clue to a more exact determination of age. Because of the similarity of their stratigraphic posi— tions above the Carrizo sand and the similarity of the ferruginous beds partly composing them, the Reklaw and Bigford members of the Mount Selman formation have heretofore been regarded as contemporaneous. The geographic and stratigraphic positions of the fos- siliferous, ferruginous sandstones north of Leming in the vicinity of Toudouze’s ranch house, Atascosa County, suggests that they represent the eastward ex- tension of the Bigford member from northern Frio County. If this is true and if the Leming and the Scruggs Creek localities should prove to represent the same zone, then, on the assumption that the conglome crate is the basal part of the Reklaw, it would appear that the Bigford is not the exact equivalent of the Rek— law, but is older and intervenes between the Carrizo sand and the Reklaw. UnfOrtunately the available fossil collections do not afford conclusive paleontologic evidence either for or against this possible stratigraphic relationship. 1 OUTCROPS OF CONGLOMERATE EAST OF TYLER BASIN The bauxite investigations were not-extended to the east side of the Tyler basin, that is, the west flank of the Sabine uplift. However, the Eocene formations shown on the geological map of Texas (1937)::along the northwest side of the basin are also indicated as, present on the east side where they dip gently‘tothe They should be easily recognizable in _ 38 PROBABLE REKLAW AGE OF A FERRUGINOUS CONGLOMERATE IN TEXAS west and northwest into the basin. The undifferen- tiated Wilcox group is represented as cropping out in a broad area on the main part of the Sabine uplift; the Carrizo sand appears around the western and southern edge of the Wilcox area as a belt generally less than 2 miles wide but widening on the southwest flank of the uplift to a maximum of 9 miles. Parallel- ling the Carrizo belt on the west and south is the Reklaw member of the Mount Selman formation, whose belt of outcrop is generally narrow, but which widens in places to a maximum of about 10 miles. The type area of the Reklaw member of the Mount f Selman formation is the town of Reklaw and vicinity in east—central Cherokee County near the southwest corner of Rusk County. In the course of a hasty trip to Reklaw I saw these exposures: On U. S. Highway 84, in Rusk County, 0.6 mile east of Reklaw, a cut shows 15 ft. of greenish-gray marine sand, weathering to yellow, brown, and reddish brown, strongly glauconitic in the upper part, sparingly glau— conitic in the lower part; a few streaks of clay are pres- ent in the lower part; the sand contains a few poor imprints of shells. Presumably this is a typical section of the Reklaw member. On the same highway at the southwest edge of Reklaw a long cut in the slope leading down to the bottom land of Mud Creek reveals the following section (pl. 4 0) : Section on U. S. Highway 81,, in cut at southwest edge of Reklaw, Cherokee County, Terr. Feet Sand, ferruginous, weathered _________________________ 10 Lenses of sand and gravel, ferruginous, irregularly bedded, indurated in part to conglomerate; a few pebbles of quartzitic sandstone present _____________ 2 t04 Unconformity. Sand, light-colored, rather loose, irregularly bedded, crossbedded, medium to fine __________________________ 3 to 5 171-. It was not possible at the time to determine satisfac- torily the age of the gravel and conglomerate in this section. Because of the proximity of the section to Mud Creek the conglomeratic bed and the sand above it perhaps would be most apt to be considered a Pleistocene terrace deposit. However, this section is at a topo- graphically lower level than the typical section of the Reklaw member 0.6 mile east of the town of Reklaw, and the possibility that the conglomeratic bed is a basal bed of the Reklaw member, which passes to the east be- neath the main body of the member, seems worthy of consideration. Such a possibility seems strengthened by the finding of similar ferruginous conglomerates on or near outliers of the Reklaw (as mapped) at the fol- lowing localities in central and northern Rusk County: State Highway 64, 3.5 miles west by north of Hender- son, about 0.3 mile east of Brumley Creek; State High- way 323, in cut on hill 3.2 miles northwest of Henderson ; several outcrops along State Highway 322, between Craig, 7 miles, and Monroe, 14 miles, north of Henderson. LIST OF CONGLOMERATE LOCALITIES Localities at which the ferruginous gravel and/con- glomerate or either were observed north, northwest, and southwest of the Tyler basin are listed below. Pebbles, cobbles, and in places boulders, of quartzite derived from beds of quartzitic sandstone in the Wilcox group were seen in the gravel or conglomerate at many places; failure to note their presence does not neces- sarily mean that they were absent, for they were found at nearly every locality at which a careful search was made for them. Impressions of roots and rootlets were common in the quartzitic sandstones. Pebbles of chert derived from the Edwards limestone were seen in the conglomerate only in Caldwell and Wilson Counties. The position of the conglomerate facies was generally at upland levels, many of them actually being on the divides between stream systems. Observed Occurrences of Ferruginous Gravel and Conglom- erate in Texas, Exclusive 01 East Side of Tyler Basin CASS COUNTY: Low hill about 3.5 miles northwest of Alamo Mills, 4 miles north of Springdale. Altitude about 300 ft. Two localities on public road, 2.5 and 3 miles northeast of‘ Douglasville. Altitude about 280 ft. Four localities on public roads near New Hope School, 0.5 mile southwest, 0.4 mile and 0.9 miles north, of New Hope School, which is 1.7 miles north of Marietta. These localities appear to be near the 350-ft contour. Two localities on public roads, 2 and 4 miles northwest of Marietta. These localities are near the 325-ft contour. MORRIS COUNTY! Public road 1.3 miles north of Naples; noted pebbles of quartzitic sandstone. Altitude 425+ ft. Two localities in public road, 0.9 and 1.5 miles north by west of Naples. Altitude about 400 ft. Two localities in public road, 1 and 1.5 miles north by west of Omaha. Altitude about 400 ft. North-south public road, just north of Little Boggy Creek Valley, 4.5 miles southwest of Omaha. East-west road just east of Prayer Branch, 5.5 miles south- west of Omaha. TITUS COUNTY: Public road, 0.8 mile northwest of Cookville. East-west public road, 1.8 miles south by west of Cookville. Two localities on public road, east and west of Swananloe Creek, 4.6 miles south by west of Cookville; numerous pebbles of quartzitic sandstone noted. CAMP COUNTY : Public road, 1.4 miles north of Pittsburg. ‘ East of north-south road, 2.2 miles north of Pittsburg. East of St. Louis Southwestern Railway, north of branch of Big Cypress Creek, 4 miles north of Pittsburg. Two localities on public roads, 3 and 4 miles north-northeast of Pittsburg. Public road, southeast-facing slope, 0.2 mile southeast of New Hope Church, 4.5 miles northwest of Pittsburg; quartzitic sandstone pebbles noted. Public road 1.5 miles north of Leesburg. THE GRAVEL AND CONGLOMERATE L 39 FRANKLIN COUNTY: About 0.25 mile south of Missouri—Kansas—Texas Railroad near county line, about 1 mile west Of Newsome (Camp County) ; pebbles of quartzitic sandstone noted. Public road just south of Scroggins. North-south public road, south-facing slope of Dry Cypress Creek, 0.25 mile northwest of Scroggins; quartzitic sand- stone pebbles noted; thickness 2 to 4 ft. See section on page 34. Public road, 4.5 miles north by west of Scroggins. Four localities on north-south roads, 2.7, 3.5, 3.7, and 3.8 miles north-northwest of Scroggins. Two localities on east-west public road, 2.6 miles and 3.3 miles northwest of Scroggins. Cut on State Highway 11, about 0.9 mile northwest of Winnsboro (Wood County) ; many cobbles and boulders of quartzitic sandstone. HOPKINS COUNTY: State Highway 11, 0.75 mile northwest of Franklin County line; coarse ferruginous sand and conglomerate fills a channel 5 ft deep in fine ferruginous sand and sandstone. Same highway 5.6 and 6.2 miles northwest of Franklin County line. Two localities just north Of Wood County line, 4 and 4.3 miles west of Winnsboro (Wood County). woon COUNTY: State Highway 11, 2.4 miles east of Winnsboro; many cobbles and boulders of quartzitic sandstone. Same highway at Chalybeate, 3.7 miles east of Winnsboro and 0.5 mile east of Chalybeate. Same highway 6.1 and 6.3 miles east Of Winnsboro. Same highway at Camp County line. North-south road 0.2 mile north of State Highway 11, 6 miles east of Winnsboro. State Highway 37, 0.85 and 2.55 miles soutlrsouthwest of Winnsboro. Same highway, 3.25 miles south-southwest of Winnsboro; thickness 1 to 2 ft; many cobbles and boulders of quartzitic sandstone with root and rootlet impressions. North-south road, 10.5 miles north of Quitman. Low hill, 0.25 mile west of Coke, 9 miles north of Quitman ; cobbles and boulders of quartzite are abundant. Four additional localities within 0.8 mile west and north- west of Coke. North of northeast—southwest road, 2.7 miles west by south of Coke. East-west road ditch, 2 miles north of Forest Hill School, 5.25 miles north-northeast of Quitman; thickness 4 ft; quartzitic sandstone pebbles noted. See section on page 33. Public road, 5 miles north by east of Quitman, 0.2 mile northwest of Clover Hill Baptist Church; thickness 1 to 4 ft. Public road, 0.85 mile north-northwest of Quitman. Public road, 4.1 miles north-northwest of Quitman. Public road, 5.4 miles north—northwest of Quitman. Three localities in public road, 3.4, 4.6, and 5.1 miles east of Alba. ‘ Near east-west private road to liguite mine, 3 miles south by east of Alba. U. S. Highway 69, 1.85 miles south-southeast of Alba. Near crest of east-facing slope of Cottonwood Creek Valley, 2.1 miles west of Golden; thickness about 1 ft; quartzitic sandstone pebbles noted. VAN ZANDT COUNTY: Ridge 2.5 miles east by north of Gland Saline; thickness 2 to 3 ft; cobbles of quartzitic sandstone noted. Hill south of road, oveilooking Sabine River Valley, 4.5 miles northeast of (hand Saline; thickness seveIal feet , pebbles of quartzitic sandstone noted. East-west road, 2.5 miles east-southeast of Grand Saline, 0.6 mile south of Texas and Pacific Railroad; pi‘bblcs' and cobbles of quartzitic sandstone noted; thickness several feet. Near public road, 2.7 miles southwest of Silver Lake. Public road, 2.8 miles southwest of Grand Saline. Northwest-southeast ridge, 2.9 miles southwest of Grand Saline. Hill, 4.8 miles southwest of Grand Saline, 1.4 miles south by west of Antioch Church. Old Grand Saline—Canton road, 7.7 miles southwest of Grand Saline, 1.4 miles southwest of Clark School; pebbles, cobbles, and boulders of quartzitie sandstone abundant in the poorly exposed gravel. See page 32. Low hill, 7.7 miles southwest of Grand Saline, 0.3 to 0.7 mile northwest of Star Church; ferruginous, pisolitic glomerate about 1 ft thick with pebbles and cobbles of quartzitic sandstone underlain by impure bauxitic material. Road ditch in northeast—facing slope of valley of Little Saline Creek, 7.6 miles south by west of Grand Saline, 1.2 miles east of Oakland School; pebble of quartzitic sandstone noted; thickness 5 ft. See section on page 32. Road ditch 7.1 miles south of Grand Saline 1.2 miles south by w est of Corinth Church. Road ditch 8... ’ miles south by east of GIand Saline 0.9 mile noith of Glower School. Public Ioad, 11.8 miles south by east of Grand Saline, 1.8 miles east of Colfax. Public road, 4 miles northeast of Ben Wheeler, 1.6 miles east by north of Bethlehem School; thickness 2 ft. Four localities on State Highway 19 as f0110Ws: 3 miles south of Canton; 7.2 miles south of Canton (altitude about 540 it.) ; 7.6 miles south of Canton (altitude about 560 ft), quartzitic sandstone boulders noted; 12 miles south of Canton, 1.6 miles north of county line at aban- doned club house (altitude about 500 ft.). East-west road, 0.3 mile west of State Highway 19, 0.3 mile north of Henderson County line. Altitude about 520 ft. SMITH COUNTY: Questionable, on the Van-Garden Valley road, 42 east of Van (Van Zandt County). HENDERSON COUNTY: North-south road, 1.2 miles south of Athens. FREESTONE COUNTY: Public road, 6.8 miles east by north of Fairfield, 0.35 mile north of site of Pilot Knob School; pebbles of quartzitic sandstone common. Public road, 1.6 miles south by east of 'l‘urlington. Road ditch. 3.2 miles east of Dew, about 0.9 mile east of site of Burleson Hill School. Road, 1.1 miles south-southeast of site of Burlcson Hill School. ROBERTSON COUNTY: Hill near road, 2.3 miles north of Easterly. Cut on U. S. Highway 79, 2.8 miles northeast of Easterly. Franklin-Bremond road, 1.5 miles northwest of Franklin; pebbles of quartzitic sandstone noted. . Calvert road, 1.6 miles west-southwest of Franklin. miles 40 PROBABLE REKLAW AGE OF A FERRUGINOUS CONGLOMERATE IN TEXAS MILAM COUNTY: Cliff overlooking Little River Valley, 2.9 miles north-north- east of Gause; quartzitic sandstone pebbles noted. See section, page 34. Road, 2.2 miles northeast of Gause, 0.5 mile northwest of International and Great Northern Railroad. Along and near road, 1.2 miles northwest of Gause. Ridge near road, 1.2 miles west of Gause, west of l’inoak Creek. LEE COUNTY: Two localities on U. S. Highway 77, 1.4 and 1.9 miles north of Tanglewood. Ridge, 2 miles northwest of Tanglewood; pebbles of quartz- itic sandstone noted (pl. 4D). North of road, 2.5 miles west by south of Lexington; quartzitic sandstone pebbles noted. Altitude about 400 ft. BASTROP COUNTY: Public road, 4.2 miles west by north of Rosanky, 0.3 mile north of Missouri—Kansas—Texas Railroad. Altitude about 500 ft. Piney Branch, north of northwest-southeast road, 1.6 miles north-northwest of Rosanky; 425-ft contour, 80 or 85 ft lower (down dip) from the preceding. Road, 3.5 miles west by south of Rosanky. Altitude about 450 ft. CALDWELL COUNTY: McMahan road 1.4 miles west by north Of Delhi; quartzitic sandstone pebbles noted. Altitude about 520 ft. East-west road, 4.6 miles north-northeast of Harwood (Gonzales County), 11.3 miles east-northeast of Luling, west of a small branch Of Sandy Creek; quartzitic sand— stone pebbles and a few chert pebbles from the Edwards limestone noted. Altitude about 420 ft. Scruggs Creek just west of north-south road, 4 miles north by east of Harwood (Gonzales County), 10.5 miles east- northeast of Luling; quartzitic sandstone pebbles noted. See section on page 35. Altitude 425 ft. East-west road, 2.5 miles north by east of Harwood (Gon- zales County), 9.4 miles east by north of Luling; quartzitic sandstone and chert pebbles noted. Altitude 475 ft. N orth-south road, 1.5 miles north by west of Harwood (Gon- zales County). Altitude about 425 ft. GONZALES COUNTY: U. S. Highway 90, 1.5 miles west of Harwood; quartzitic sandstone pebbles noted. Altitude about 375 ft. Hill south of road overlooking Guadalupe Rivér Valley, 3 miles west-southwest of Belmont. Altitude about 440 ft. WILSON COUNTY: A draw on a side road northeast of Highway 181, 3.8 miles northwest of Floresville; pebbles of quartzitic sandstone and chert from the Edwards limestone noted. SOURCE OF QUARTZITIC PEBBLES AND COBBLES One of the distinguishing lithologic characteristics of the gravel and conglomerate throughout the extent of its occurrence in Texas and Arkansas is the presence in it of more or less waterworn transported pebbles, cobbles, and even boulders of very fine-grained quartzitic sandstone, many of them bearing the impressions of roots and root— lets. Quartz pebbles are rare or wanting. The quartz— itic .pebbles and cobbles may be rare or abundant at given localities. They are especially abundant in the Vicinity of Winnsboro in northeastern Wood County, Tex., where the quartzitic cobbles and boulders abound in such num- bers that they have been utilized in the construction of ‘stone fences, the walls of buildings, and in outlining walks and flower beds. The nearest observed source of this quartzitic sandstone t0 Winnsboro is in the vicinity of Sulphur Springs, Hopkins County (see map, pl. 3), where both southwest and east of the town masses of this kind of rock occur in place in the lower part of the Wilcox group (pl. 5). If there are no nearer sources, the distances these rocks were transported are 15 to 25 miles. Other Observed occurrences of the quartzitic sandstone in place in the Wilcox group in Texas are: 3.3 miles south by west of Emory, near a school house, in Rains County, a low hill capped by a more or less fractured and disturbed, but essentially continuous, layer of quartzitic sandstone 2 to 4 ft thick, showing many im— pressions of rootlets; just east of a cemetery, 8 miles west Of Canton, 1.2 miles southeast of Caney Church, Van Zandt County, many large, loose boulders of quartzitic sandstone essentially in place, showing the impressions of roots and rootlets; ledge of typical quartzitic sand- stone in north-facing slope of Walnut Creek Valley, 1.5 miles south of Malakofi', 600 ft west of road, Henderson County; masses of typical quartzitic sandstone with root impressions along road 1.5 miles west by north of Goetz, 13 miles east-northeast of Streetman, Freestone County; loose pieces Of the quartzitic sandstone were ob- served at several places on the outcrop of the lower part of the Wilcox in western Freestone and southern Lime— stone Counties, probably indicating the occurrence Of this rock at undetermined places in those areas; in northeastern Texas, south of U. S. Highway 67, 0.4 mile southwest of Simms, Bowie County, many large boulders of quartzitic sandstone essentially in place. In Arkansas quartzitic masses bearing the impres— ' sions of roots and rootlets were Observed in place in the lower part of the Wilcox formation at the following localities: at the surface and in clay pits 3.5 to 4.5 miles north-northeast of Texarkana, within 2 miles north of U. S. Highway 67 (pl. 5A) ; south of State Highway 4, 3.5 miles east-southeast of Hope, Hempstead County; road ditch two miles west by north of Sutton, 5.4 miles south-southeast of Emmet, Nevada County. Most of the quartzitic masses both in Texas and Arkansas were low in the Wilcox, but some appeared to be at higher levels. Wherever seen in place the quartzitic sandstone bore the impressions of roots and rootlets, a characteristic later found to be useful in identifying the transported pebbles and cobbles in the gravels and conglomerates. SIGNIFICANCE Apparently the gravels and conglomerates described on preceding pages have been regarded heretofore as nothing more than Quaternary terrace deposits or sur- ficial accumulations of rubble locally cemented with iron oxide to a conglomerate. The facts here recorded THE GRAVEL AND CONGLOMERATE 41 seem to justify attributing to this bed a more important place in the Tertiary section of the western Gulf region. The alinement of the observed occurrences of this bed" (114 localities west and north of the Tyler basin in Texas) on or near the narrow belt of outcrop of the Reklaw member of the Mount Selman formation is one outstanding fact. Another significant fact is the in- clusion throughout the length of this bed of transported, more or less water-worn pebbles, cobbles, and, in places, boulders derived from beds of quartzitic sandstone bearing root impressions, in the undifferentiated Wilcox group. The resistant character of the conglomeratic portions of the bed has resulted in their preservation as outliers on low hills from which younger, softer beds have been removed; for this reason, sections showing the relation of the bed to overlying beds are rare, but two sections showing the gravel and conglomerate over- - lain by finer sands believed to be part of the Reklaw unit are described on pages 33, 34. Because of these facts the suggestion that the gravel and conglomerate form a basal bed of the Reklaw member and mark a widespread unconformity in the Eocene series should be given a more thorough field test than I was able to give it at the time. During the course of the investigations the belt of outcrop of the main body of the undifferentiated Wilcox group was crossed transversely at many places between Bowie County in the northeast and Wilson County in the southwest. It is notew0rthy that no outcrops of ferruginous conglomerate resembling the conglomerate described on previous pages were observed on the VVil— cox belt except along its eastern edge adjacent to the belt of outcrop of the Reklaw member. If the ferru- ginous conglomerate is nothing more than surficial rub— ble or a Quaternary terrace deposit, it would seem reasonable to expect that this kind of conglomerate would be present at many place and at different levels in the Wilcox belt. Stream gravels of late Tertiary or Quaternary age observed at a few places were usually easily distinguishable from the gravels here presumed to mark the base of the Reklaw. The former have ter- race-like profiles along stream valleys and a greater variety of pebbles, many of which were derived from more distant sources. The belt of outcrop of the Queen City sand member of the Mount Selman east and south- east of the Reklaw belt seemed also to lack occurrences of ferruginous conglomerate, but this area was not so extensively explored as was the Wilcox belt. Is it possible that the ferruginous conglomerate marks the base of the Claiborne group? Should this question be answered in the affirmative, it would.mean that the true Carrizo sand should be classed as Wilcox, for it lies stratigraphically below the conglomerate from Lee County at least as far to the southwest as Wilson County. Should the zone from which fossils were collected at the Scruggs Creek locality and near String Prairie be found to represent the Bigford member of the Mount Selman formation, then the Bigford would fall within the Wilcox group, for this zone also lies below the con- glomerate. Berry (1922, pp. 3, 4) correlated both the Carrizo sand and the Bigford member of the Mount Selman formation with the Wilcox group on the basis of fossil plants. Trowbridge, Deussen, and Murray and Wil- liams also accepted this age determination, but most other authors have regarded the Carrizo as the basal formation of the Claiborne group in Texas. This opin— ion seems to have been based in part at least on the existence of an unconformity at the base of the Carrizo sand, which has been recognized by Trowbridge (1923, p. 91), Deussen (1924, p. 57), Wendlandt and Knebel (1929, pp. 1350, 1351), Getzendaner (1930, p. 1435), Plummer (1933, p. 613), Stenzel (1939, p. 64; 1951, pp. 1818—1822) , and others. However, if the presence of an unconformity (or disconformity) marked by a basal gravel and conglomerate can be satisfactorily deter- mined at the base of the Reklaw unit, and this uncon- formity can be traced from Nevada County, Ark., to Wilson County, Tex., a distance of 450 miles, its im- portance as a stratigraphic boundary is obvious. The relative merits of this unconformity and the one at the base of the Carrizo sand as marking the base of the Clai- borne group should be reviewed, giving critical con- sideration to the soundness of the evidence on the basis of which the Carrizo sand has been correlated with the Claiborne group. The paleontologic evidence as inter- preted by Gardner seems to favor the Claiborne age of the ferruginous fossil-bearing sandstone beneath the ferruginous conglomerate at the Scruggs Creek locality in Caldwell County. But the fossils from this locality and from all the other localities studied by her in the present connection are poorly preserved, and among them all not one species known to be restricted to a lim- ited horizon has been identified. The evidence for the Claiborne age of these faunas would seem, therefore, to fall considerably short of finality. As Gardner has already explained (p. 37), her opinion is based largely on the Claiborne aspect of the fossil assemblages. It should be emphasized that the fossils from only one of the localities studied by Gardner, the Scruggs Creek locality, were observed to be stratigraphically below the ferruginous conglomerate. There is, however, strong paleontologic evidence that the collection from near String Prairie came from the same zone as the Scruggs Creek collection. The relationships of all the other collections to the conglomerate, whether above or below it, remain to be determined. In conclusion, emphasis is placed on the need for a thorough, detailed study of the VVilcox-Claiborne rela- tionships along the belt of outcrop of these groups in central and northeast Texas and in southwest Arkansas. On the assumption that ferruginous conglomerate is a 4:2 PROBABLE REKLAW AGE OF A FE-RRUGINOUS CONGLOMERATE IN TEXAS basal bed of the Reklaw member of the Mount Selman formation, the fact that many of the occurrences of the conglomerate lie geographically either a little east or a little west of the belt of outcrop of the member as mapped in 1937 (see pl: 3) indicates the need for a revision of the mapping. The presence in the conglom— e1ate of pebbles and cobbles of quartzitic sandstone and other reworked Wilcox plastics showing various degrees of V 'ater wear, and the apparent absence of pebbles from soulces to the VV est and north, more distant than the Edwards limestone of the Cretaceous, raises the ques- tion as to the drainage conditions that must have existed to account for the transportation of fragments of the quartzitic rock from its places of outcrop along the western part of the Wilcox belt, eastward for distances of 5 to 20 miles across a bordering coastal plain to a sea margin that extended for more than 450 miles, at least from Nevada County, Ark, to Wilson County, Tex Apparently the drainage basins did not head inland far enough to enable the streams to erode the older formations. Another question is, what were the depositional conditions under which the fine-grained quartzitic sandstones bearing the impressions of roots and rootlets were formed at widely separated localities in early Wilcox time? The photographs reproduced in plate 5 A, D, suggest that these impressions record the presence of plants which grew under swampy or marshy conditions at the close of the deposition of this particular facies of sand. As observed, the impressions aie 1est1icted to the upper 10 or 12 in. of the rock layers REFERENCES Berry, E. W., 1922, Additions to the flora of the Wilcox group: U. S. Geol. Survey Prof. Paper 131. Dellssen, Alexander, 1914, Geology and ground waters of the southeastern part of the Texas Coastal Plain: U. S. Geol. Survey Water-Supply Paper 335. 1924, Geology of the Coastal Plain of Texas west of Brazos River: U. S. Geol. Survey Prof. Paper 126. Dumhle, E. T., 1920, The geology of east Texas: Texas Univ. Pull. 1869. Get/endaner, F. M. 1930, Geologic section of Rio Grande Em- hayment Texas, and implied history. Amer. Assoc. Petroleum Geologists Bull. vol. 14, no. 11, pp. 1425—1437 (esp. p. 1435). l\( 11119th William 1‘\96 The Eocene Tertiary of Texas east of the Brazos River. Acad Nat. Sci. Philadelphia Pioc., 1895, pp. 89—160. Murray, G. E. and Thomas, E. P., 1945, Midway-Wilcox surface stratigraphy of Sabine uplift, Louisiana and Texas: Amer. Assoc. Petroleum Geologists Bull. vol. 29, no. 1, pp. 45.70, map in pocket. Renick, B. 0., and Stenzel, H. B., 1931, The lower Claiborne on the Brazos River: Texas Univ. Bull. no. 3101, pp. 73—108. l’lunnner, F. B., 1933. Cenozoic systems in Texas: Texas Univ. Pub. 3232, pp. 519—818, (1932). Stenzel, H. B., 1939, The geology of Leon County: Texas Univ. Pub. 3818, 295 pp., (1938) . 1941, The surface relationship of the Carrizo sand of Texas (Abstract) : Tulsa Geol. Soc. Digest, vol. 9, pp. 70—72. 1951, Buried hill at Wilcox-Carrizo contact in east Texas: Amer. Assoc. Petroleum Geologists Bull. vol. 35, no. 8, pp. 1815—1825. ’l‘rowbridge, A. 0., 1923, A geologic reconnaissance in the Gulf Coastal Plain of Texas near the Rio Grande: U. S. Geol. Survey Prof. Paper 131D. \Vendlandt, E. A. and Knebel, G. M., 1929, Lower Claiborne of east Texas, with special reference to Mount Sylvan Dome and salt moVemonts: Amer. Assoc. Petroleum Geologists Bull. Vol 13, no 10, pp. 1347— 1375 INDEX B Page Bauxite ...................................................................... 32, 34 Bigford member, as Wilcox formation. 41 age and stratigraphci position__ ,,,,,,,,,,,,,,, . 37 C Carrizo sand as part of Wilcox group ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 41 age and stratigraphic position ____________________________ 37 origin .......................... . . ., 35 section, Milan] County __________________________________________________ 34 Conglomerate, character _______________________________________________________ 32 Claiborne age ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 41 distribution, Van Zandt County. ,,,,,,,,,,,,,,,,, . . 32—33 localities, Bastrop County ________ _ _. ... _ , , . . 40 Caldwell County _____________________________________ . ,,,,,,,,,,,,,, 40 Camp County ........................................................ 38 Cass County __________ . 38 Franklin County ....................................... 39 Freestone County _____________________________________ 39 Gonzales County ___________ 40 Henderson County .......... 39 Hopkins County ____________ _ 39 Lee County __________________________________________________________ 40 Milam County ______________________________________________________ 40 MorrisCounty.._..._ . 38 Robertson County ....................... . 39 Smith County _________________________ . 39 Titus County ______________________________________________________ 38 Van Zandt County ___________________________________________________ 39 Wilson County ______________ 40 Wood County. 39 outcrops in Arkansas ..................................................... 34 quartzitic sandstone in .................................................. 40, 41 section, Franklin County ................................................. 34 Milam County ....................................................... 34 Van Zandt County ................................................... 32 Wood County ........................................................ 33 stratigraphic significance .......................................... F Fage Fauna, analysis of assemblages ............................................... 37 from locality at Belmont ......... . 36 from locality near Harwood... , . . . . . . . 36 from locality near Leming ............................................... 36-37 from locality near Lemlng ....... , .............................. . .. . .. . .. 37. irorn locality at String Prairie... .. from locality near Willow Springs. . _ . .. from section-oil Scruggs Creek__ .. , , Fossils. See Fauna. (J Gardner, Julia, iaunal interpretation ....... quoted; ............................ Gravel (intimated). See Conglomerate. I-Q Investigation, purpose ....................................................... 31 Long, Joe ..................................................................... 31 Miller, Marc ................................................................. 31 Monroe, Watson H .................. 31 Murray, G. E., and Thomas, E. P .......... . 32 R Reklaw member, section near Reklaw ........................................ 38 type area ...................... , ........................................... 38 S Sand, fossiliierous, section ..................... . ................................ 35 Sandstone, quartrltic, character ......................... . . .................... 40 outcrops.. rootlets, in. _ Stenzel, H. B ................................................................ _ T—VV Tertiary system .............................................................. 41 Van uplift ...................................... , .............................. 33 Wilcox formation, in Arkansas ........................................ . ....... 34 43 G UNITED STATES DEPARTMENT OF THE INTERIOR EOLOGICAL SURVEY 32° 31° 3o,“ Eocene Paleocene and older rocks 0 Fine sands in part glanconitic, Midway group and pre-Midway EXPLANATION Post - Rekla stratigraphic units Reklaw member of Mount Selman formation and shales, more or less sandy; ferruginons conglom- erate at base UNCONFORM/TY Carrizo sand Fine to coarse sand and sandstone, argillaceous in upper part UNCONFORM/TY 9s Wilcox group undifferentiated Sands, sandstones, clays, sandy clays, and lignites Tm units (Cretaceous and Paleo- zoic rocks) Shales, limestones, and other rock A Outcrops of quartzitic sandstone or quartzite O bserved outcrops of ferruginous gravel, in part indurated to con- glomerate; believed to mark the base of the Reklaw member of the Mount Selman formation Contact Dashed where approximately located D "‘"fi'" Fault Dashed where approximately located. U, apthrown side; D, downthrown side The part of this map showing the distribution of the Wilcox group and part of the Mount Selman formation is essentially as shown on the geological map of Texas issued in 1937 by the U. S. Geo— logical Survey, with revisions in Leon County XREAL DI TERTIARY hr (1 Tm L Tm STRIBUTION OF inLoox AN .QUARTZITIC SA III PROFESSIONAL PAPER 243 PLATE 3 Tmh Tm Tm : \§\\\\§\\\\k\\ \\\ \\ \ . . h ‘\ . .\\ ya.“ \ . \ Tm « l V "‘ “t“ \ “~3\\\:\&\ v . \ \ \ ..' ‘ ‘..‘ ~“ ' I ' . V a. ‘» \ ‘3 ‘ ‘ j j\\‘ : ’er \‘$‘§ ~ [a \ “ 1 '5“ Q 32° 31° 30° INTERIORVGEOLOGICAL SURVEYi WASHINGTON. Di c.4952 94° D LOWER PAR? OF CLAIBORNE GROUPS XND OCCURRENCES OF NDSTONE AND FERRUGINOUS GRAVEL AND CONGLOMERATE 100 Miles 4 I I I I I I I I I OG» CCCCCC Cenomanian Ammonite + Fauna from the Mosby Sandstone of Central Montana GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—D. Cenomanian Ammonite Fauna from the Mosby Sandstone of Central Montana By W. A. COBBAN SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—D UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1953 UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. 5. Government Printing Office Washington 25’, D. C. - Price 55 cents (paper cover) C O N T E N T S Page Abstract ______________________________________________________________________________________________________ 45 Introduction __________________________________________________________________________________________________ 45 Stratigraphy of Mosby sandstone member of Colorado shale- _ _ ________________-_______-___-_'__- _____________________ 45 Age of Mosby sandstone member ________________________________________________________________________________ 46 Localities from which fossils have been collected ___________________________________________________________________ 47 Description of species __________________________________________________________________________________________ 47 References ____________________________________________________________________________________________________ 54 Index ________________________________________________________________________________________________________ 55 ILLUSTRATIONS PLATES 6— 9. M etoicoceras ______________________________________________________________________________ Follows index 10—12. Dunveganoceras ___________________________________________________________________________ Follows index FIGURE 3. Whorl sections of Dunveganoceras ______________________________________________________________________ 53 III 220799—52 CENOMANIAN AMMONITE FAUNA FROM THE MOSBY SANDSTONE OF CENTRAL MONTANA By W. A. COBBAN ABSTRACT The Mosby sandstone member of the Colorado shale contains an ammonite fauna consisting of two new species of M etoicoceras and one new species and one new subspecies of Dunvegcmoceras. Associated fossils include gastropods in great abundance but of little variety, and a few pelecypods. A very late Cenomanian age is assigned. The fauna is unknown elsewhere in the United States except for one possible occurrence in north-central Wyo- ming. Species of Dunveganoceras closely related to those of the Mosby sandstone member have been described from the Dun- vegan and Smoky River formations of northwestern Alberta and northeastern British Columbia. The Mosby sandstone member is fine to very fine-grained cal- careous sandstone of shallow water origin. A section measured at Mosby, where the Colorado shale is 1,930 ft thick, and the Mosby member lies 743 ft below the top, is recommended as the type section. INTRODUCTION The Mosby sandstone member of the Colorado shale contains the ammonite genus Metoicocems, represented by the new species M. mosbyense and M. muellem', and the genus meegcmocems, with the new species D. parvum and the new subspecies D. albertense monta- name. ms). been found in the member. The fauna is of further interest in that it represents the youngest of the Ceno- . manian zones recognized in the western interior of the . ‘ oegcmocems. . and southern types. United States. Ammonites from nine localities were studied. Me- toz'cocems is represented by parts of 75 individuals and Dunveganoceras by about 50. Most of the material was collected by Mr. Oscar O. Mueller, attorney at law, of Lewistown, Montana, who kindly donated his col- 1 lections to the United States Geological Survey. The 1 photographs were made by Mr. Nelson W. Shupe of the ; Geological Survey. The types are deposited at the United States National Museum. STRATIGRAPHY OF MOSBY SANDSTONE MEMBER OF COLORADO SHALE The Mosby sandstone member of the Colorado shale was named by Lupton and Lee (1921, p. 263) for expos- ‘ ures near Mosby P. O. on the Musselshell River in east- central Montana. There the Colorado shale is 1,930 ft thick, and the Mosby sandstone member lies 743 ft below the top. This is a curious mingling of a southern genus 1 (Metoicocems) and a northern genus (Dunveganoce- . These are the only ammonite genera that have ‘ The member is exposed extensively on the Cat Creek and Devils Basin anticlines and in the intervening area. It also crops out on the flanks of the Little Rocky Moun- tains and the Judith Mountains. The member is chiefly light-gray fine to very fine- grained calcareous sandstone that commonly has a con- cretionary habit. It ranges from massive to shaly in short distances and shows cross bedding and ripple marks. The sandstone is hard and forms an easily rec- ognized low ridge or hogback rising above the softer Colorado shale. At the type locality the member con- sists largely of two 5.5-ft sandstone beds separated by ‘ 11 ft of sandy shale. Fossils, chiefly gastropods, are locally very abundant, apparently concentrated by current action (pl. 7, fig. 1). A smooth gastropod, Pseudomelam'a hendm'clcsoni Hendersomiforms the bulk of the fossils, with many concretions composed almost entirely of this species. Several other gastropod genera, including ornate forms, are present. Pelecypods are limited to E wogym colum- bella Meek, Tm‘gonocallista, orbiculata (Hall and Meek), and 11ndeScribed species of Geroillia, Inocem— mus, and Gryphaea. Of these, only Trigonocallz'sta- orbiculata is abundant. Ammonites, which are rela‘ tively scarce, are represented by Metoicocems and Darn- The fauna shows a blending cf northern M etoz'cocems and E mogym cola/m» belle are widely distributed from central Montana south into Texas, but are unknown in Canada, whereas Dunvegcmocems is a northern genus that is unknown south of central Wyoming. The following stratigraphic section, measured east of the Musselshell River from 14—mile east to 1/2-mile north of Mosby Post Office, in 81/2 sec. 2 and NV; sec. 11, T. 14 N., R. 30 E., Garfield County, is recommended as the type section for the Mosby sandstone member. Descriptions of part of the Colorado shale above and below the Mosby member are included to show the lithologies of adjoining strata. Beds equivalent to the lower part of the Carlile shale. Um‘t Feet 23. Shale, dark bluish-gray; forms dark outcrops bare of grass but with abundant trees-..___-_ 36.0 22. Bentonite, creamy-yellow ___________________ 0.5 45 46 Beds equivalent to the lower part of the Carlile shale—Continued Um't 21. Shale, dark-gray; weathers orange-brown; contains lenses as much as 1.5 in. thick of 'tan«weathering fossiliferous limestone. Con- tains fossils of Fairport age. (U.S.G.S. Mes. loc. 21398) ; Inoceramus cf. I. labiatus (Schlotheim), Ostrea n. sp., C'ollignoniceras woollgam' var. praecow Haas, 0. woollgan‘. var. intermedium Haas, Scaphites patulus Cobban, [sums cf. I. appendiculatus (Agas- siz), Isurus cf. I. scmiplicatus (Agassiz), Squah‘corax falcatus (Agassiz), Ptychodus . whipplei Marcou _________________________ 20. Bentonite, greenish-gray ____________________ 19. Shale, dark-gray; weathers orange brown; contains a few layers of limestone less than, 1grin. thick 18. Bentonite, gray and greenish-gray, finely \ micaceous; weathers whitish ______________ 17. Limestone and shale, gray .16. Shale, black-gray; __________________________ 15. Bentonite, creamy and gray _________________ 14; Limestone and shale, gray; weathers orange brown; limestone layers not more than 2 in. thick; contains a small species of smooth oyster and fish scales, bones, and teeth _____ Beds equivalent to the upper part of the Greenhorn formation. 13. Shale, gray, calcareous; weathers creamy white; upper part contains a few white- weathering limestone concretions __________ 12. Bentonite, creamy-White, stained rusty by limonite; contains at base a few white- weathering limestone concretions _________ 11. Shale, darkvgray; weathers medium gray; noncalcareous in lower part but slightly cal~ careous in upper, contains a few thin shaly siltstone and very fine-grained calcareous sandstone layers _________________________ 10. Shale, gray; contains closely spaced gray cal- careous concretions that weather pale laven- der gray and contain veins of white, yellow, and brown calcite ________________________ Beds equivalent to the middle part of the Greenhorn formation. 9. Shale, dark bluish-gray, noncalcareous Mosby sandstone member. 8. Sandstone, light-gray, fine to very fine-grained, thin-bedded to shaly, soft, more or less argil- laceous; contains dark shale partings and a few buif-weathering calcareous concretions that are septarian with brown, yellow, and white calcite. Top of bed contains a sprink- ling of black chert pebbles as much as %-in. in diameter. Unit weathers buff gray to tan, and forms an inconspicuous outcrop. Spar- ingly fossiliferous (U.S.G.S. Mes. 10c. 21397) ; Trigonocallista orbiculata (Hall and Meek) 7. Shale, dark bluish-gray, noncalcareous; con- tains numerous very fine-grained sandy part- ings in lower part _______________________ 6. Sandstone, light-gray, very fine-grained, thin- bedded, ripple-marked, cross-bedded; con- tains dark shale partings particularly in Feet 5.6 0.2 3.0 1.0 0.1 0.2 0.2 1.3 15. 5 2.8 3.5 1.0 7.5 5.6 11. 0 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 Beds equivalent to the middle part of the Greenhorn formation—Continued Mosby sandstone member—Continued Um‘t Feet upper 2 ft.; commonly passes laterally into bud-weathering silty, calcareous concretions. Unit weathers tan and forms a conspicuous ledge. Marine gastropods and pelecypods abundant in distantly spaced calcareous concretionary masses. (U.S.G.S. Mes. loc. 21396) ; Germ‘llia sp., Inoceramus aff. I. fra- gilis Hall and Meek, Gryphaea n. sp., Emo- gym columbella Meek, Trigonocallista orbi- culata (Hall and Meek), Pseudomelam‘a hendricksom‘ Henderson, Lunatic cf. L. dako- tens-is Henderson, Gyrodes com‘adi Meek, Anchura? sp., Trachytm’ton n. sp., Metoico- ceras mosbyense Cobban, Dunveganocems alberteme subsp. montanense Cobban ______ 5. Shale, dark-gray; contains sandy layers up to 1 in. thick 4. Sandstone, gray, very fine-grained, thin- bedded; contains dark shale partings ______ Beds probably equivalent to part of the Belle Fourche shale. 3. Shale, dark bluish-gray; contains a few soft very fine-grained gray sandstone layers as much as 2 in. thick. Few gypsum-encrusted pelecypods (U.S.G.S. Mes. loc. 21395) ; Gry- phaea sp., Ewogw‘a columbella Meek _______ 23. 5 2. Shale, dark bluish-gray; contains large widely spaced calcareous concretions that weather bluish gray and buff and contain veins of brown and yellow calcite _________________ 1. 5 1. Shale, dark bluish—gray ____________________ 10. 0+ 5.6 3.5 1.5 AGE OF MOSBY SANDSTONE MEMBER OF COLORADO SHALE The ammonites of the Mosby sandstone are not known with certainty outside central Montana. The nearest similar fauna occurs in a calcareous sandy unit in the Frontier formation about 100 ft below the Wall Creek (“First”) sandstone member on the east flank of the Kaycee anticline, 1.5 miles south of Kaycee, Wyo. The collection from that locality (U.S.G.S. Mes. 10c. 23456) consists of fragments of 10 or 11 specimens of a species of M etoz'cocems. Many of these fragments match speci- mens of M. mosbyense, n. sp., of comparable size in the stoutness of the whorls and coarseness and density of ribbing. A few fragments suggest more slender indi- viduals than are known from the Mosby member. The lack of any specimens referable to the common Mosby species, M. muellem’, n. sp., or to the Mosby Dunvegano- cams is difficult to explain. Just below the main group of sandstone beds in the Frontier formation (about 200 ft below the top) on the south side of the Bighorn Mountains, four miles east of Arminto, Wyo. (U.S.G.S. Mes. loc. 23492), is a unit of sandy shale containing Dun/veganocems cf. D. conditum Haas and a species of M etoz‘cooeras closely related to M. mosbyense, n. sp. Up to a diameter of 60 to 70 mm this species seems to be identical to M. CENOMANIAN AMIVIONITES FROM THE MOSBY SANDSTONE 47 mosbyense, but at greater diameters the whorls are much more densely ribbed. This densely ribbed Metoico— ceras and fragments of a Dunvegamocems that may be D. conditum Haas also have been found together in the Frontier formation on the east side of the Bighorn Mountains near Buffalo, Wyo. The other species of Metoicocems and Dunvegomo- cems from the western interior differ so much from the Mosby forms that there is no question that they mark separate fauna] zones. A continuous sequence of rocks bearing these genera has not been found at any one locality, but a consideration of two fairly fossili- ferous sections makes possible the recognition of defi- nite zoning of the M etoicocems—Dun’veganoceras faunas. On the north flank of the Black Hills the Greenhorn formation contains at its base M etoicoceras cf. M. prac- cow Haas and Dunvegcmocems cf. D. pondz' Haas, and near the top, Metoz'coceras whitei Hyatt. Associated with M. whitei are Sciponocems gracile (Shumard) and Scaphites delicatulus Warren. Near Buffalo, on the east flank of the Bighorn Mountains, Sciponocems gracile and Scaphites delicatulus occur together in the shale less than 100 ft above the Frontier formation, whereas M etoicoceras of. M. praecom is present in sand- stone about 120 ft below the top of the Frontier for- mation. Concretions in the upper 50 ft of the Frontier formation contain the densely ribbed M etoz'cocems and fragments of Dunveganocems cf. D. conditum. From these two sections it is apparent that three M etoi- cocems levels can be recognized which in ascending order are (1) M. praecow, (2) a densely ribbed new species, and (3) M. whitez’. Of these species the Mosby forms are closely related to the densely ribbed species. This close age assignment is also supported by the Mosby species of Dunveganoceras, which are much nearer D. conditum than D. pondi. Inasmuch as the costal cross section of the ultimate whorl is quadrate for D. panda, round for D. conditum, and ogival for D. albertense montcmense, it is probable that the Mosby species is a little younger than D. conditum, assuming the evolutionary trend was from a truncate to a sharply arched venter. It thus appears that the following four M etoz'cocems levels can be recognized in the Montana- Wyoming area: M. whitez' (youngest zone) M. mosbyense, n. sp M. n. sp., (densely ribbed species) M. pmeooa: (oldest zone) Dunveganocems albertense montaneme, n. subsp., the common representative of this genus in the Mosby sand- stone member, SO closely resembles D. albertense (War- ren) that an approximate time equivalence seems cer— tain. The Mosby form, which differs in small details from VVarren’s species, seems best to be regarded as a geographic subspecies. D. albertense is considered by Warren and Stelck (1940, . 149) to be Upper Ceno— manian. This assignment seems reasonable and is fur- ther supported by the position of the Mosby fauna in regard to the Metoicooems whitei zone. The zone is considered to mark the base of the Turonian (Spath, 1926, p. 80; Muller and Sch nck, 1943, fig. 6). A late Cenomanian age for the Motby fauna is suggested also by the presence of at least four older Cenomanian faunas in the western interior (Cobban, 1951, p. 2197, fig. 2). LOCALITIES FROM WHICH FOSSILS HAVE BEEN COLLECTED Ammonites have been colliacted from the Mosby sand- stone member of the Colorado shale at the following localities in central Montana, for which the U. S. Geo- logical Survey Mesozoic locality number, name of col- lector, and year of collection are given: 10976. A. J. Collier, 1921. About 7.5 miles northeast of Zortman, in sec. 1,3, T. 26 N., R. 25 E., Blaine County. 18741. J. B. Reeside, Jr., 1938. Bull Creek, west side of Cyprian dome, on southwest flank of Little Rocky Mountains, in sec. 35, T. 25 N., R. 23 E., Phillips County. 21396. W. A. Cobban, 1948. About 1,4-mile northeast of Mosby, in the NEIA sec. 11, T. 14 N., R. 30 E., Garfield County. l 21484. O. O. Mueller, 1948. lNear south side of~spi11way of Yellow Water Reservoir, in the SW34 sec. 7, T. 13 N., R. 26 E., Petroleum County. 21485. O. O. Mueller, 1948. About M-mile north of Yellow Water Reservoir, in the SW34 sec. 1, T. 13 N., R. 25 E., Petroleum County. 21486. 0. o. Mueller, 1948, About 1 mile southwest of Yellow Water Res rvoir, in the NE1/4 sec. 14, T. 13 N., R 25 E., Petrfileum County. 21487. 0. O. Mueller, 1948. About 1.5 miles south-southwest of Yellow Water Reservoir, in the NWV; sec. 23, T. 13 N., R. 25 E., Petroleum County. 21488. O. O. Mueller, 1944. One mile south-southeast of Yellow Water Reservoir, in the SEMSEIA sec. 14, T. 13 N., R. 25 E., Petroleum County. 21490. O. 0. Mueller, 1944.1 South side of Yellow Water Reservoir, in the frwv. sec. 7, T. 13 N., R. 26 E., Petroleum County. 21662. W. A. Cobban, M. M. Knechtel, S. H. Patterson, W. T. Pecora, 1948. East Side of Morrison dome, on south flank of Little Rocky Mountains, in the SEMNWJA sec. 7, T. 24 N., R. 25 E., Phillips County. 21955. W. A. Cobban, C. T. Moore, 0. O. Mueller, 1949. Six miles west of Winhett, in sec. 1, T. 14 N ., R. 25 E., Petroleum County.‘ DESCRIPTION OF SPECIES Family Acanthoceratidae de Grossouvre, 1894 Subfamily Metoicoceratinae Hyatt, 1903 Genus Metoicocdras Hyatt, 1903 1903. M etoicoceras Hyatt, U. Si Geo]. Survey Mon. 44, p. 116. 1920. M etoicoceras Hyatt. Bose, Texas Univ. Bull. 1856, p. 200 (dated 1918, issued 1920). 48 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 1928. Metoicocems Hyatt. Adkins, Texas Univ. Bull. 2838, p. 248. 1931. M etoicoceras Hyatt. Reeside and Weymouth, U. S. Nat. Museum Proc., Vol. 78, art. 17, no. 2860, p. 19. 1938. Metoicoceras Hyatt. Roman, Les Ammonites jurassiques - t crétacées, p. 437. 1942. JIEtoicoceras Hyatt. Moreman, Jour. Paleontology, vol. 6, no. 2, p. 210. 1944. ’ Metoicocems Hyatt. Shimer and Shrock, Index fossils of North America, 1). 561. ' Metoicoceras mosbyense Cobban, n. sp. Plate 6, figures 1—14; plate 7, figures 1—3 Shell large for the genus, laterally compressed, mod- erately involute; umbilicus about Tie the diameter in young stages, gradually widening to 1/5 the diameter in older stages. Flanks flattened; venter rounded to di— ameter of 10 mm, flattened or excavated between diam- eters of 10 to 120 mm, and rounded beyond 120 mm. Sculpture consists of straight to slightly sinuous ribs, less than 36 per whorl, that bear spirally elongated ventral nodes to a diameter of 120 mm, and conical ventrolateral nodes and bullate umbilical nodes to a diameter of 45 mm. Suture complex for the genus. At the earliest stage observed, about a diameter of 4 mm, the whorls have a broadly rounded venter, sharply rounded ventrolateral shoulder, and flattened flanks. At this early stage the sculpture consists of a row of 5 or 6 large ventrolateral nodes per half whorl that are conical, sharp, and directed straight out. Opposite nodes are connected by a low forward-arched rib bear- ing on each side of the midline of the venter an incon— Spicuous low conical ventral node that is barely dis- cernible. By a diameter of 6 mm the ventral nodes are distinct. Each node of a. pair is separated from the other by a distance a little less than the distance between a ventral nbde and the nearest ventrolateral node. Each ventro— lateral node passes into a low inconspicuous rib that trends straight across the flank to the umbilical shoul- der. The cross section is rather quadrate with about equal distance from the middle of a ventrolateral node to the umbilicus and t0 the ventral node on the opposite side of the venter (pl. 6, fig. 14). At a diameter of 10 mm the middle of the venter is flattened and bordered by the small ventral nodes, which become slightly elongated spirally. The venter nar- rows and the flanks lengthen radially. The ventrola- teral nodes are much reduced in size, becoming more nearly the size of the ventral nodes. Between the ven- trolateral nodes on the flank are smaller intercalated ventrolateral nodes. Each ventrolateral node is con- nected to a ventral node by a low forward inclined rib. The larger ventrolateral nodes terminate low straight flank ribs that extend to the umbilical shoulder. These ribs almost disappear midway on the flank, but become stronger again near the umbilicus. Between diameters of 10 and 15 mm the ventral and ventrolateral nodes become of equal size. The flank continues to widen and the venter narrows so that at a diameter of 15 mm the flank is as wide as the distance between opposite ventrolateral nodes. Each pair of ventral nodes is connected by a broad straight rib. At a diameter of 15 mm a half whorl has about 11 ventral ribs. By a diameter of 20 mm the flank is wider than the distance between opposite ventrolateral nodes. These nodes are not placed as far behind the ventral nodes as in younger stages. The umbilical ribs become stronger and even elevated into radially elongated nodes. The density of ribbing increases to 12 ventrolateral ribs per half whorl. Two ventrolateral ribs are present to each umbilical rib. Between diameters of 20 and 45 mm the whorls con- tinue to become more compressed laterally with the venter progressively narrowed. The ventral nodes be— come more spirally elongated, whereas the ventrolateral nodes gradually decrease in size and finally disappear at a diameter of about 45 mm. The ribs become straight and strong, attaining their maximum strength at a diameter of about 35 mm. The density of ventrolateral ribs increases from 13 to 15 per half whorl. Between diameters of 45 and 90 mm. the venter be- tween the spirally elongated nodes becomes smooth or only weakly undulated. The sculpture becomes weak and the umbilical nodes gradually disappear. The number of ventrolateral ribs increases from 14 to 18 per half whorl. Between 90 and 110 mm diameter there is a marked decrease in rib density from 18 to 12 per half whorl. The ventral nodes weaken and the venter becomes less excavated. These nodes disappear between diameters of 110 and 130 mm, and the venter rounds and becomes broadly undulated by the ribs widening ventrally and crossing the venter as broad swellings. Beyond 130 mm diameter the ribs, which have been straight since the loss of the ventrolateral nodes, may, arch forward on crossing the venter. The number remains low— about 11 or 12 per half whorl. Complete senile specimens were not observed. Frag— ments of the largest specimens suggest that some in- dividuals attained diameters of more than 200 mm and possibly as much as 250 mm. The holotype, an incomplete specimen 180 mm in diameter, has an umbilical width of about 36 mm 06 of diameter), a whorl thickness of about 55 mm (30 per cent of diameter), and a rib density of 12 per half whorl. It is septate t0 the last quarter whorl. Dimensions in millimeters, ratios (in parentheses), of the dimensions to the diameters, and the number of ribs per half whorl of the types are as follows: CENOMANIAN AMMONITES FROM THE MOSBY SANDSTONlj 49 Kind ofspecimen and U.S.N.M. number Digger Umbilical Width Whorl height 7 Whorl thickness R‘ijfighhau Paratype 1083168. _____________________________ 13. 5 1. 5 (0. 11) - 7. 4 (0. 55) 6. 2 (0. 46) 11 Paratype108316b ___________ ' __________________ 20. 0 2.0 ( . 10) 12 0 ( . 60) 7. 8 ( . 39) 13 Paratype 1083179. _____________________________ 37.0 2. 5 ( . 07) 21 0 ( 57) 16. 0 ( . 34) 10 Paratype 1083198. _____________________________ 39. 0 4. 7 ( . 12) 21 0 ( 54) 15. 2 ( . 39) 12 Paratype 1083188. _____________________________ 42. 3 4. 2 ( 10) 23. 2 ( . 55 14. 8 ( . 35) 13 D0 ______________________________________ 58.0 6. 6 ( 11) 31. 6 ( . 54 19. 9 ( 34) 15 D0 ______________________________________ 87. 0 10. 5 ( .12) 48. 2 ( . 55 26. 2 ( 30) 18 Paratype 108318b _____________________________ 60. 0 5. 0 ( 09) 34 7 ( . 58 17. 7 ( 29) 14 Paratype 108317b__ 57. 0 4. 8 ( 09) 32 3 ( 57) 18. 7 ( 33) 16 D0 ___________ 79. 5 6. 4 ( 08) 45 5 ( 57) 23. 0 ( 29) 17 Paratype 108319b__ 110. 0 12. 7 ( 12) 58 4 ( 53) 36. 0 ( 33) 12 Holotype 108315 ______________________________ 180. 0 36. 0 ( 20) 82 0 ( 45) 55. 0 ( 30) 12 The nearest described American species is probably Metoz'cocems acceleratum Hyatt (1903, p. 127, pl. 14, figs. 11—14) from the Eagle Ford shale of Texas. That species is known only from immature specimens that closely resemble the comparable young stages of M. mOSbyense but lack umbilical nodes and lose the ven- trolateral nodes at a smaller diameter. Metoz'cocems whim: Hyatt (1903, p. 122, pl. 13, figs. 3—5; pl. 14, figs. 1—10, 15) from the basal Turonian of the Western Interior and Texas is readily distinguished from M. mosbyeme by maintaining ventrolateral nodes out to a much greater diameter. Likewise, M. swallovii (Shumard) (1859, p. 591), M. swallowiz' var. macmmt Stephenson (1952, p. 209, pl. 51, figs. 4—7), M. 071188600- stae Stephenson (1952, p. 210, pl. 58, figs. 6—8), M Zatoventer Stephenson (1952, p. 209, pl. 53, figs. 1—9; pl. 54, figs. 9~11), M. gibbosum Hyatt (1903, p. 121, pl. 15, figs. 5—8), and M. ornatum Moreman (1942, p. 211, pl. 32, fig. 4, text fig. 2c), all from the Woodbine and Eagle Ford formations of Texas, carry the ventrolat- eral nodes to much greater diameters than does M. mosbyense. The species from the Woodbine formation (M. s'wallooiz', M. latoventer, and M. crassicostae) are also more evolute. The specimen from the Coleraine formation in Minnesota figured by Bergquist (1944, p. 30, pl. 10, figs. 10—12) as M etoicocems afi. M. swallom'i (Shumard) is considerably stouter than M. mosbyense and the ventrolateral nodes persist to greater diameters. The Specimens described by Haas (1949, pp. 15—20, pls. 5—7, text figs. 5—9) as M etoz’cocems whitei subsp. prac- 0090 from the lower part of the Cody shale near Grey- bull, Wyoming, are much more evolute and the loss of nodes and the rounding of the venter occurs much earlier. Haas’s form is very different from M. whitei, occurs in older strata, and should be regarded as a separate species. From the Upper Cenomanian or Lower Turonian of Coahuila, Mexico, Bfise (1918, p. 205, pl. 12, figs. 1—3) figured as “M etoec‘ocems sp. nov.” a specimen about as stout as M. mosbyense of comparable diameter with similar rib spacing and with every second or third rib extending to the umbilicus. It differs, however, by its flexuous ribbing and wider umbilicus. B6se’s specimen was later assigned by J ones to the new species M. bb’sez' Jones (1938, p. 127, pl. 10, figs. 1—3), the holotype of which has ventrolateral nodes persisting to a much greater diameter than on M. mosbyense. Of the European species M. mosbyense has the same number and arrangement of ribs and nodes as M. per- m'nguz'erez' (Grossouvre) ( 912, p. 19, pl. 2, fig. 3), but differs by its much narro ‘er umbilicus. M etoicoceras dumasi (Grossouvre) (1912, p. 23, pl. 2, fig. 1) seems , close to M. mosbg/ense although it is stouter and the ventrolateral nodes persist to a greater diameter. Metoz'cocems petmschecki (Grossouvre) (1912, p. 22, pl. 2, fig. 2), M. gowdom‘, (Grossouvre) (1912, p. 20, pl. 1, fig. 1), and M. anti uum Karrenberg (1935, p. 139, pl. 31, fig. 13) are In re evolute. The specimens figured by Petrascheck (1902, p. 140, pl. 7, figs. 3—5, text fig. 5) as Pulclzellia geslz'm'ana (d Orbigny) froni the Upper Cenomanian of Saxony closely resemble M. mosbyense in its younger stages, but the Saxon species loses its ventral nodes at a; much smaller diameter and the ribs are more flexuous.) Types: Holotype, U.S.N.M. 108315; figured para- types, U.S.N.M. 108316a—b, 108317a, 108318a, 108320; unfigured paratypes, U.S.N.M. 108317b, 108318b, 108319a—b. Occurrence: U.S.G.S. Mes. 100. 21396, 21484—21487, 21490, 21662, 21955. i Metoicoceras muélleri Cobban, n. sp. Plate 6, figures 15, 16; plate 8, figures 1—7 ; plate 9 Shell large for the genus; larger, thinner, more in- volute, and smoother than M. mosbyense. Flanks flat- tened; venter rounded to diameter of 10 mm, flattened or excavated between diameters of 10 and 140 mm, and gradually rounded between 140 and 190 mm. Ribs weak, straight to sinuous, and as numerous as 46 per whorl. Ventrolateral nodes disappear by diameter of 11 mm and ventral nodes are lost between diameters of 100 and 150 mm. Suture complex for the genus. The growth stages are shown by paratype U.S.N.M. 108322a, an adult specimen of 215 mm diameter. This specimen was broken up and the inner whorls freed to a diameter of about 9 mm. 50 'SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 At a diameter of 9 mm the whorl cross section is nearly quadrate, with broadly rounded venter, sharply rounded ventrolateral shoulder, and flat, nearly smooth flanks. On each side of the venter is a row of small rounded nodes. The nodes of a row occur in pairs as shown by Hyatt (1903, p. 119, pl. 11, fig. 14) for the early stages of M etoicocems swallovii (Shumard). Five ventrol teral nodes are present on the half whorl of 9 mm dialleter. At that diameter they are rounded and as large as, the ventral nodes, but below that diam- eter they are larger than the ventral nodes and quite pointed. Ea :h ventrolateral node is situated back from the apicad node of a ventral pair by an angle of about 30 degrees, and is separated from it by a distance com- parable to th it between the two rows of ventral nodes. A low inconspicuous straight rib trends from each ven- trolateral node about half way to the umbilicus. Between 9 and 11 mm diameter a small node appears in the space between the pairs of nodes of a ventral row, and by13 mm all ventral nodes are of equal size. The ventrolateral nodes rapidly become smaller than the ventral nodes and disappear by a diameter of 11 mm. FrOm each ventral node a small rib extends back to the ventrolateral node, or after that node disappears, to the position Where it would occur, then bends and trends straight toward the umbilicus, although rapidly weak- ening and disappearing high on the flank. ,, Between 9 and 17 mm diameter the venter gradually narrows and the flank widens. At a diameter of 17 mm the ventral nodes elongate spirally, and the ribs number 14 per half whorl. Between 17 and 24 mm the venter continues to narrow, the flanks continue to widen, the whorls become more laterally compressed, and the ven- trolateral margin shifts to the position of the ventral nodes. The ribbing becomes more pronounced and the density increases to 15 ribs per half whorl. The ribs, which are somewhat sigmoidal, extend gradually farther \ down the flank. Between 24 and 40 mm the rib density increases to 16 per half whorl, and the ribbing attains its maximum strength. The ribs are sigmoidal, strongest near the venter, and about every third one extends to the um- bilicus. The venter, which is flat, has an excavated appearance owing to the rim of closely spaced spirally elongated ventral nodes. On this specimen the venter has a slight constriction just ahead of the nodes termi- nating those ribs that extend to the umbilicus. There . are six constrictions on the half whorl of 40 mm diameter. At diameters greater than 40 mm the sculpture gradu- ally weakens and the ribs become straight and broad. 1 By a diameter of 100 mm they are so broad and flat that ‘ the spaces Separating them are only half as wide. The ventral nodes are low and rather poorly defined. Between diameters of 135 and 150 mm the rib density is reduced to 10 per half whorl, the nodes disappear, and the venter is flat but no longer excavated. How— ever, the ribs become stronger and cross the venter as broad folds. Between 150 and 200 mm the venter grad- ually rounds, the ribbing remains strong, and the inter- coastal areas become as broad as the ribs. , There are about 10 ribs per half whorl. At diameters greater than 200 mm the ribs become weaker, narrower, and more numerous. At a diameter of 210 mm the rib count increases to 14 per half whorl. ‘ Metoz'cocems muellem' becomes prOgressively more evolute throughout its growth after the first few whorls. Measurements of 21 specimens show a gradual increase in the ratio of the umbilical diameter to the diameter of the shell from 6 percent at a shell diameter of 62 to 68 mm to 21 to 24 percent in shells more than 230 mm in ‘ diameter. The whorls are at first stout with quadrate cross sections, but rapidly become laterally compressed as growth continues. The ribbing shows a progressive increase in number per half whorl from 13 at shell diameter of 15 mm to 23 at a diameter of 94 mm. It abruptly decreases to 11 to 15 between 116 and 118 mm diameter, and then gradually declines to about 10 at 150 mm. The number remains low to a diameter of about 210 mm, but at greater diameters the rib count . increases to 15 at a diameter of 300 mm. About seven volutions make up an adult shell. The species is large for the genus. One of the largest speci- mens at hand, unfigured paratype U.S.N.M. 108325, attains a diameter of 301 mm. The body chamber is incomplete, but a full half whorl is preserved. The dimensions in millimeters ratios of the dimen- sions to the diameters, and the number of ribs per half whorl of the types are as follows: CENOMANIAN A1VLMONITES FROM THE MOSBY SANDSTONE’ 51 Kind of specimen and U.S.N.M. number Diameter Umbilical width Whorl height Whorl thickness Ribgggglhalf Paratype 1083223. _____________________________ 14. 5 8. 2 (O. 57) 13 D0 ______________________________________ 17. 0 14 Do ______________________________________ 20. 0 15 Do ______________________________________ 39. 3 4.0 (0.10) 22.5 ( .57) 12.8 (0.33) 16 DO ______________________________________ 50. 0 16 Do ______________________________________ 135. U 10 Do ______________________________________ 150.0 10 Do ______________________________________ 170. 0 10 Do ______________________________________ 210. 0 14 Para/type 108323a. _____________________________ 43. 5 4. O ( 09) 24. 3 ( 56) 12. 6 ( 29) 18 Paratypel'18324 _______________ 60.5 4.3 ( 07) 34.5 ( 57) 17.6 ( 29) 19 Paratype 108323b- _ - ________________ 81. 5 22 D0 _____________________________ 113.0 11. 5 ( 10) 62.0 ( 55) 29. 0 ( 26) Paratype 10832216 _____________________________ 92. 4 9. 4 ( 10) 52.1 ( 56) 23.2 ( 25) 18 ______________________________________ 147.3 21.3 ( 14) 73.1 ( 49) 37.0 ( .25) 12 Paratype 1083220 ______________________________ 62. 5 4. 0 ( 06) 36. 7 ( 59) 17. 0 ( 27) 19 ______________________________________ 151.0 22.5 ( 15) 75.0 ( 49) 35.5 ( .23) ‘ 9 Paratvp6108322d ________________ , ____________ 151.3 21.0 ( 14) 74.5 ( 48) 35.0 ( .23). ig _______________________________________ 190. 0 HolotyZpe 108321 ______________________________ 118.0 7.2 ( 06) 68.0 ( 58) 28. 6 ( .24) 15 ______________________________________ 222.0 36. 0 ( . 16) 107.0 ( 48) 51. 3 ( . 23) 10 Paratype108322e ______________________________ 254.0 56. 3 ( .22) 111.0 ( 44) 55. 7 ( .22) 13 Paratype 108325 ______________________________ 301. 0 65. 0 ( 21) 132. 0 ( 44) 68. 5 ( . 23) 15 Metoz‘cocems muellem' can be ordinarily readily dis- tinguished from its associate, M. mosbyense, by its thin- ner whorls, weaker sculpture, and persistency of a flattened venter to a much greater diameter. It is also more involute, lacks umbilical nodes, and loses the ventrolateral nodes at a much younger stage. There are a few specimens with characters of each species. These may have a combination of the whorl and umbilical pro- portions of M. muellem' and the coarse sculpture of M. mosbyense, or the ventrolateral nodes may persist out to diameters of 20 or 30 mm, which is greater than on typi- cal M. muellem' and smaller than on M. mosbyense. M etoz’cocems muellem' differs in many respects from other American species with thin whorls and weak sculpture. M etoz‘cocems acceleratwn Hyatt (1903, p. 127, pl. 14, figs. 11—14), M. kanabense Hyatt (1903, pl. 15, figs. 9—11), and M. imuz'm' Moreman (1927, p. 92, pl. 13, figs. 3, 4) are all weakly ribbed compressed forms that lack umbilical nodes, but these species retain their ventrolateral nodes ,to greater diameters than does M. muellem'. The compressed specimen with flexuous ribs from Utah figured by Stanton (1893, p. 168, pl. 38, figs. 1, 2) as “Buchz'ceras swallovi” differs from M. muellem' by maintaining ventrolateral nodes out to a greater diameter. The specimen described from New Mexico by Herrick and Johnson (1900, p. 213, pl. 27, figs. 3, 4) as “Buchiceras swallow var. puercoensz's” shows some resemblance to M. muellem' by its fairly smooth shell, but the New Mexico form is stouter and has smaller umbilicus, fewer ribs, and simpler suture. The nearest described European species is Metoz'co- Gems bureuué (Grossouvre) (1912, p. 22, pl. 1, fig. 2) from the Upper Cenomanian, which seems to differ from M. muellem' only by lacking distinct ventral nodes and by having the ribs curved back on the outer part of the flank. Metoicocems pontieri Leriche (1905) from the base of the Turonian of northern France is a thin densely ribbed species like M. mellem' that differs chiefly by the rounding of the venter at a much earlier ‘ stage. The species is named for Mr. Oscar O. Mueller of Lewistown, Montana, whose large collections of Mosby ammonites made possible this study. Types: Holotype, U.S.N.M. 108321; figured para- types, U.S.N.M. 108322c, 108323a—b, 108324; unfigured paratypes, U.S.N.M. 108322a—b, 108322d—e, 108325. Occurrence: U.S.G.S. Mes. 100. 10976, 21484, 21486, 21487, 21955. Subfamily Acanthoceratinae Wright, 1951 Genus Dunveganoceras Warren and Stelck, 1940 1940. Dunveganoceras Warren and Stelck, Royal Soc. Canada, Trans, 3d ser., vol. 34, sec. 4, p. 149. 1949. Dunveganoceras Warren and Stelck. Haas, Am. Mus. Nat. History Bull., vol. 93, art. 1, p. 20. 1951. Dunveganocems Warren and Stelck. Haas, Am. Mus. Novitates, no. 1490, p. 14. Dunveganoceras albertense (Warren) subsp. montanense Cobban, n. subsp. Plate 10, figures 1—7; plate 11; text figures 3b—e The holotype of Dunvegamcems albertense (War- ren) (1930, p. 21, pl. 1, figs. 1, 2) .is a large shell of 350 mm diameter with an umbilical width of 140 mm (40 percent of diameter). The nodes disappear on the ultimate whorl and the whorl cross section becomes ogival. The ribs are strong, straight, and moderately spaced, with 18 on the last whorl. Nearly all the specimens of Dumveganocems from the Mosby sandstone member seem to fall within the scope of D. albertense (Warren). The umbilical widths are similar, the strength of ribs and nodes seems identi- cal, and the last whorls have about the same number 52 of ribs, lose their nodes, and assume an ogival cross section. However, there are some differences that seem to warrant treating the Mosby form as a subspecies. The inner whorls are more densely ribbed, with 16 to 18 ribs per whorl between diameters of 70 and 100 mm in comparison with 13 to 14 at similar diameters on the holotype of D. albertense; the nodes are lost at a smaller diameter; the venter rounds earlier where the ribs cross it; and the ultimate whorl is stouter. The holotype of Dunvegcmocems albertense mona tomense is a shell of 320 mm diameter, with umbilical SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 whorl attains a coastal height of 95 mm and a thickness of about 100 mm. About half the body chamber is preserved. The nodes are lost by a diameter of 200 mm, and by a diameter of 240 mm the coastal whorl section is distinctly ogival. The ribs, which number 20 per whorl, are st1aight and inclined slightly for- ward. The suture is unusual in that the ventral lobe has shifted away from the median plane on the younger part of the last septate whorl (pl. 10, fig. 7 ). The dimensions in mm, ratios of the dimensions to the diameters, and the number of ribs per whorl of w1dth of 140 mm (44 percent of d1ameter). The last the types are as follows: Kind of specimen and U.S.N.M. number D2333” Umbilical width Whorl height Whorl thickness Rwlhsoirjler 67. 2 18. 8 (0. 28) 29. 5 (0. 44) 28. 8 (0. 43) 16 91.0 28.5 ( .31) 36.5 ( .40) 36.7 ( .40) 17 133. 5 45. 0 ( . 33) 54. 5 ( . 41) 54. 2 ( . 46) 18 185.0 61. 0 ( . 33) 73. 3 ( .40) 72.0 ( . 39) 19 265.0 95.0 ( .36) 102.0 ( . 38) 91. 0 ( . 34) 18 255. 0 96.0 ( 38) 92. 5 ( 36) 72. 2 ( 28) 18 310.0 122.0 ( 39) 98.0 ( 32) 80.0i( 26:|:) 18 250.0 100.8 ( 40) 87.7 ( 35) 70.04( 284) 20 320.0 140.0 ( 44) 95.0 ( 30) 100.04( 314) 20 __________________________ 130.0 112.0 __________ Measurements of 16 specimens show a gradual widen- ing of the umbilicus from 28 percent at a diameter of 67 mm to 44 percent at a diameter of 320 mm. The number of ribs per whorl increases from 16 at diameter of 67 mm to an average of 18 at diameter of 150 mm, and at all later stages the rib count remains between 18 and 20. The largest specimen examined (unfigured paratype U.S.N.M. 1083270), a fragment of a body whorl with a height of 130 mm and thickness of 112 mm, indicates that the subspecies attained diameters of more than 400 mm. Types: Holotype, U.S.N.M. 108326; figured para- types, U.S.N.M. ' 108327a—b, 108329; unfigured para- types, U.S.N.M. 108327c, 108328. Occurrence: U.S.G.S. Mes. 10c. 18741, 21396, 21484, 21486—21488, 21662, 21955. Dunveganoceras parvum Cobban, n. sp. Plate 12, figures 1, 2; text figure 3a ' Shell small for the genus, moderately evolute with umbilical width about 35 percent of the diameter. Whorls stout, about as wide as high; umbilical wall steep; flanks broadly rounded; venter of ultimate whorl rounded. Sculpture consists of forwardly inclined ribs, ' which on the septate whorls bear ventral and ventro— lateral nodes. The holotype, an adult shell with a little more than half the body chamber preserved, has the following dimensions in millimeters: Diameter: 178 . Umbilical width : 62.6 (35 percent of diameter) Whorl height: 634 Whorl thickness: 651‘ Whorls below a diameter of 60 mm are not preserved. The ribs on the holotype are narrow, inclined forward, extended to the umbilical shoulder, and number 19 on the last whorl. On the last septate whorl each rib is strongly bent forward on leaving the umbilical shOul- der, but abruptly curves back a little on the lower part of the flank, straightens, and crosses the rest of the flank with a forward inclination of about 20 degrees. On the body chamber the ribs become straighter and less inclined. Up to a diameter of about 70 mm each rib terminates in strong ventral and ventrolateral nodes. Between diameters of 70 to 90 mm these nodes merge into large rounded nodes, and the ribs cross the venter. By a diameter of 120 mm the ribs absorb the nodes and become high, but flat-crested, 011 crossing the venter. By a diameter of 150 mm both the costal and intercostal cross sections of the whorl are rounded on the venter. This is the smallest known species of meegano- cams. It is readily distinguished from D. albertense (Warren) by its small size and early loss of nodes. The smallest species described from Canada, D. pouce- coupeme Warren and Stelck (1940, p. 150, pl. 2; pl. 3, figs. 2, 5), is larger and has a truncate venter. D. conditum Haas (1951, p. 5, text figs. 2—9) from the Frontier formation of Wyoming attains a much larger size and is more densely ribbed. Types: Holotype, U.S.N.M. 108330; unfigured para- type, U.S.N.M. 108331. Occurrence: U.S.G.S. Mes. 100. 21484, 21486, 21487, 21662. 53 CENOMANIAN AlVLMONITES FROM THE MOSBY SANDSTONE ———_—‘ ’4‘ ~~~ - ’ --_-_-,» --_ ‘~‘§ (z ‘~--v — __——-~ ~‘- s ’ r” I a, Dunveyanoceras parvum Cobban v (paratype, U.S.N.M. 10832710) at diameters of 170, 200, and 265 mm illustrating changes in costal cross section; e, D. a. montanense Cobban (holotype, U.S.N.M. 108326) at diameter of 283 mm. FIGURE 3,—Whor1 sections, natural size, of Dunveganocems from Mosby sandstone member. (holotype, U.S.N.M. 108330) at diameter of 168 mm; b~d, Dunvegamoceras albertense (Warren) subsp, montanense Cobban 54 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 REFERENCES Bergquist, H. R., 1944., Cretaceous of the Mesabi iron range, Minnesota: Jour. Paleontology, vol. 18, no. 1, pp. 1—30, pls. 1—11. ' ‘ Btise, Emil, 1918, On a new ammonite fauna of the Lower Turon- ian of Mexico: Texas Univ. Bull. 1856, pp. 173—257, pls. 12—20, text figs. 1—7. Cobban, W. A., 1951, Colorado shale of central and northwestern gs Montana and equivalent rocks of the Black Hills: Am. Assoc. Petroleum Geologists Bull., vol. 35, no. 10, pp. 2170— 2198. De Grossouvre, Albert, 1912, Le Crétacé de la Loire-Inférieure et de la Vendée: Soc. sci. nat. Ouest France Bull., ser. 3, vol. 2, pp. 1—38, pls. 1—3, text figs. 1—8. Haas, Otto, 1949, Acanthoceratid Ammonoidea from near Grey- bull, Wyoming: Am. Mus. Nat. History Bull., vol. 93, art. 1, pp. 1—39, pls. 1—15, text figs. 1—17. 1951, Supplementary notes on the ammonoid genus Dun,- veganoceras: Am. Mus. Novitates, no. 1490, pp. 1—21, text figs. 1—9. Herrick,’C. L., and Johnson, D. W., 1900, The geology of the Albuquerque sheet: Denison Univ., Sci. Lab., Bull., vol. 11, art. 9, pp. 175—239, pls. 27—58, map in pocket. Hyatt, Alpheus, 1903, Pseudoceratites of the Cretaceous: U. S. Geol. Survey Mon. 44. Jones, T. S., 1938, Geology of Sierra de la Pefia and paleontology of the Indidura formation, Coahuila, Mexico: Geol. Soc. America Bull., vol. 49, pp. 69—150, pls. 1—13, text figs. 1—4. Karrenberg, Herbert, 1935, Ammonitenfauna aus der nordspan- ischen Oberkreide: Palaeontographica, Band 82, Abt, A, pp. 125—161, pls. 30—33, text figs. 1—5. Leriche. Maurice, 1905, Sur la présence du genre Metoicoceras Hyatt dans la Craie du Nord de la France et sur une espece nouvelle de ce genre (Metoicocems pontien’): Soc. géol. Nord Annales, tome 34, pp. 120—124, pl. 2, text figs. 1—3. Lupton, C. T., and Lee, Wallace, 1921, Geology of the Cat Creek oil fields, Fergus and Garfield Counties, Montana: Am. Assoc. Petroleum Geologists Bull., vol. 5, no. 2, pp. 252-275, p1s._1, 2, text fig. 1. Moreman, W. L., 1927, Fossil zones of the Eagle Ford of north Texas: J our. Paleontology, vol. 1, no. 1, pp. 89-101,. pls. 13—16, text fig. 1. g 1942, Paleontology of the Eagle Ford group of north and central Texas: J our. Paleontology, vol. 16, no. 2, pp. 192—220, pls. 31—34, text figs. 1, 2. Muller, s. W., and Schenck, H. G., 1943, Standard of Cretaceous system: Am. Assoc. Petroleum Geologists Bull., vol. 27, no. 3, pp. 262—278, text figs. 1~7. Petrascheck, Wilhelm, 1902, Die Ammoniten der siichsischen Kreideformation: Beitr. Palaontologie Oesterr.—Ungarns u. des orients, Band 14, pp. 131—162, pls. 7—12, text figs. 1—8. Reeside, J. B., J r., and Weymouth, A. A., 1931, Mollusks from the Aspen shale (Cretaceous) of southwestern Wyoming: U. S. Nat. Mus. Proc., vol. 78, art. 17, pp. '1—24, pls. 1—4. Shumard, F. B., 1859, Descriptions of new Cretaceous fossils from Texas: Acad. Sci. St. Louis Trans, vol. 1, pp. 570—610. Spath, L. F., 1926, On new ammonites from the English chalk: Geol. Mag, vol. 63, pp. 77—83. Stanton, T. W., 1893 (issued 1894), The Colorado formation and its invertebrate fauna: U. S. Geol. Survey Bull. 106. Stephenson, L. W., 1952, The larger invertebrate fossils of the Woodbine formation (Cenomanian) of Texas: U. S. Geol. Survey Prof. Paper 242. Warren, P. S., 1930, Three new ammonites from the Cretaceous of Alberta: Royal Soc. Canada Trans, 3d ser., vol. 24, sec. 4, pp. 1—26, pls. 1—4. Warren, P. S., and Stelck, C. R., 1940, Cenomanian and Tu- ronian faunas in the Pouce Coupe district, Alberta and Brit- ish Columbia: Royal Soc. Canada Trans, 3d ser., vol. 34, sec. 4, pp. 143—152, pls. 1~4. INDEX [Italic numbers indicate descriptions] Page acceleratum, Metoicocema ........................................... _ 49, 50 Age of Mosby sandstone member 46~47 albertense, Dunveaanocerus ........................................ 47, 51, 52 montane'nse, Dunvepa'noceraa .............................. 45, 46,47, 61, pls. 10, 11 Anchura sp ____________________ 46 antiquum, Metoicoceras ............................................... 49 appendlculatus, Isurus ........................................................ 46 basei, Mdolcoceras ............................................................. 49 Buchiceras swallovi .................................................... 51 swallow” puercoemis ............................................... 51 bureum, Mdoicoceras .......................................................... 51 Carllle shale __________________________________________________________________ 45-46 Coltignoniceras ........................................................... 46 woollaari intermedium _ 46 woollqari praecoa: ___________________________________________________________ 46 Colorado shale ................................................................ 45 columbella. Ezowra ................ conditum, Dunveaanoceras .................................................. 46,47, 52 comadl, Gyrodes .......................................................... 46 crassicaslae, Mdoicoceraa..._._...-..~ __________________________________________ 49 dakotemis, Lunatia ............................................................. 46 delicatulus, Scaphltes __________________________________________________________ 47 dumasl. Mdoicoceras, 49 Dunveganoceras ...................................................... 45, 46, 47, 51, 52 albertense .............................................................. 47, 51, 52 monta’neme _ 45, 46,47, 51, pls. 10.11 conditum ............................................................... 46, 47, 52 pamum ............................................................. 45,52, pl. 12 pond! .......... 47 pmcecoupame ............................................................ , 52 Exowru columbella ............................................................ 45, 46 falcatus, Squalicoraz ........................................................... ‘ 46 fragilis, Inoccramus-_ 46 Frontier formation ............................................................ 45—46 Gervlllia ...................................................................... 45 galiwiana, Pulchellia .......................................................... 49 .‘u ,"4 ' .u.-. ................................... 49 aourdonl. M ‘ ‘ as ............... 49 gracile, Scipo'noceraa ........................................................... 47 Gryphaea._. .................................................... 45 sp ........................................................................ 46 Gyrodes comad! ................. 46 handmksom, Paeudomdania ................................................... 45, 4e Inocera'mm ................................................................... 46 fragilia ............................ 46 . r. . ..-. '___ _______ ,- _______ 46 interment 1m», Oolliammiceras woollaarl ......................................... 46 Intrndnnflnn _ _______________ . ____________________ 45 irwim, “"‘ ‘ In ....... ... ..-_ - 51 Isurue appendlculatus ......................................................... 46 aemlpllcutm ............................................................... 46 kanabeme, Mdalcoceraa. ’ ............. 51 labiatus, 1noceram1u...-.._.. ...- __._ . 46 latovmter, Mdolcoceras ........................................................ 49 Localities. collection .......................................................... 47 Lunatic dakozemla ............................................................ 46 macrum. Mdaicoccras swallow“ ................................................ 49 Metolcoceraa ...................... .-. _________ 45, 46, 47 accderatum ............................................................... 49, 50 Metaicoceras——Continued Page 49 49 51 49 49 49 49 .......................................... 51 51 ........................................ 49 ....................... 45, 46, 47, 48, 50, pls. 6, 7 . muellcri.. -._ 45,46,49, pls. 6, 8,9 arm/tum. ___ ................................ 49 pervinqulereL. ................................ 49 petraschekl _ . .. 49 pamleri..- ........................ 51 praecoz. ........................ 47 49, 50 macrum _______________________________ 49 whim ................................... 47,49 white! praecoz _________ 49 n. sp __________________________________________________ 47, 49 monlanensc, Dunveganoceras alber!mse.. .......... 45, 46,47, 61, pls. 10,11 mosbyeme, Metoicocems _________________ . 45, 46, 47, 48, 50, pls. 6, 7 ‘Mueller, 0. 0., collection. .................... 45 muelleri, Metoicoceraa ____________________________________________ 45. 46, 49, pls. 6, 8, 9 arblculata, Wiganocalllsta.._... .......................... 45,46 ornatum, Metaicoceras... .................... 49 Ostrea, n. sp .................................................................. 46 parvum, Dunveganoccms ________________________________________________ 45, 52, pl. 12 pervinquierei, Metoicoceras ................. 49 petrascheki, Metoicaceraa ................. , 49 pondi, Dunveganoceras. . 47 pontieri. Metoicoceraa .................... 51 pmcecoupense, Dunveyanoceras __________ 52 praecoz, C'ollignoniceraa woollaarL- 46 Metoicoceras ............................ 47 Mctoicoceras whim ______________________ 49 Pseudomelania hendn’cksonl- 45. 46 Ptychoduo whipplel .......................................... 46 puercoemla. Buchlceras 8w "“‘ --.. .-. 51 P. v :- "in 06'“ , __ ___________________ 49 References ............... 54 Scaphites ‘ " ‘ ' -. Sciponoceraa cradle ..................................................... Section, stratigraphic-.. semiplicatua. 18mm-.- Squalicoraz lalcatua. Stratigraphy ...... swallow. Buchiceraa. M etolcoceras .................... swallow macrum, Mdoicocema _. _. cwallovi pmrcomsis, Buchz‘ceraa ................................................ 51 Traclwtriton n. sp ............................................................. 46 Triaomcallista orbiculata ...................................................... 45, 46 whim, Metoicoceras ........................................................... 47, 49 white! praecox, Mdoicoceras ............................................. - 49 whipplel, Ptuchodus .................................................... _ 46 woollqarl intermedium, Collignonlceras - 46 woollgari praecoz, Collianonlceraa .............................................. 46 55 O PLATES 6—12 PLATE 6 [All figures natural size except as indicated on plate] FIGURES 1—14. Metoicoceras mosbyense Cobban, n. sp. (p. 48). 1—,7 Side, front, and rear views, and suture of a small internal mold, paratype U. S. N. M. 108316a, from locality 21955. 8,9, Front and side views of a larger specimen, paratype U. S. N. M. 108316b, from the same locality, showing the first appearance of umbilical nodes. 10, 11, Side and rear Views of a stout paratype retaining the shell, U.S.N.M. 1083173., from locality 21484. Shows the disappearance of the ventrolateral nodes and the elevation of the umbilical ribs into radially elongated nodes. 12, 13, Side and rear views of an internal mold, paratype U.S.N.M. 108318a, from locality 21487, showing the disappearance of umbilical and ventrolateral nodes. 14, Cross section of the internal whorls 9of paratype U. S. N. M. 108320, from locality 21662. 15,16. Metozcoceras mueller’i Cobban, n. Sp. (p. Front and side views of paratype Up S. N. M. 108324, an internal mold from locality 21487. GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 6 15 16 METOICOCERAS SVHHDODIOLEIW AHAEOS 1V3190’1039 L 'JJ-V'Id S'I’Z ufldVd 'IVNOISSSIOHJ PLATE 7 [All figures natural size] FIGURES 1—3. Meto’icoceras mosbyensé Cobban, n. Sp. (p. 48). Side and rear views and part of sixth from last suture of the holotype, U.S.N\.M. 108315, an internal mold from locality 21484. The arrow indicates the beginning of the body chamber. PLATE 8 [All figures natural size except as indicated on plate] FIGURES 11-7. M etotcoceras muelleri Cobban, n. sp. (p.4 9.) 1, 2, Side and rear views of a. small internal mold, paratype U. S. N. M. 1083233., from locality 21484. Shows weak- ness of sculpture and early disappearance of ventrolateral nodes. 3, 4, Side view and suture of a slightly larger internal mold, paratype U. S. N. M. 1083220, from locality 21486. 5, 6, Side and front views of a larger almost smooth internal mold, paraty e U. S. N. M. 108323b, from locality 21484. 7, Front view of the holotype, U. S. N. M. 108321, from locality 21487. hows change 1n venter from a flattened to a rounded form. GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 8 METOICOCERAS GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 9 METOICOCERAS PLATE 9 M etoicoceras muellem’ Cobban, n. sp. (p. 49). Side iiliew, natural size, of the holotype, U.S.N.M. 108321, from locality 21487. The arrow indicates the beginning of the body 0 amber. > » PLATE 10 [All figures natural size except as indicated on plate] FIGURES 1—7. Dunveganoccms albertense (Warren) subsp. montanense Cobban, n. subsp. (p. 51). 1—4, Front, rear, and side views, and suture at diameter of 45 mm of an internal mold, paratype U.S.N.M. 108327a, from locality 21955. , - 5, 6, Front and side views of a smaller paratype, U.S.N.M. 108329, from locality 21662. 7, Rear view‘of the holotype, U.S.N.M. 108326, from locality 21488. Shows ogival shape of the ultimate whorl and the asymmetrical suture. GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 10 DUNVEGANOCERAS GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE ll \ DUNVEGANOCERAS m «awmm 169-“ PLATE 1 1 [Figure three-fourths natural size] Dunveganoceras albertense (Warren) subsp. montanense Cobban, n. subsp. (p. 51). Side view of the holotype, U. S. N. M. 108326, a large internal mold from locality 21488. The arrow indicates the beginning of the body chamber. PLATE 12 [Both figures natural size] FIGURES 1, 2. Dunveganoceras parvum Cobban, n. sp. (p. 52) Side and rear views of the holotype, U. S. N. M. 108330, an internal mold from locality 21484. The arrow indicates the beginning of the body chamber. PROFESSIONAL PAPER 243 PLATE 12 GEOIDGICAL SURVEY DUNVEGANOCERAS I K! Mollusks From the Pepper Shale Member of the Woodbine Formation McLennan County, Texas GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—E GEOLOGICAL SCIENCES LIBRARY Mollusks From the Pepper Shale Member of the Woodbine Formation * McLennan County, Texas By LLOYD WILLIAM STEPHENSON SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 57—68 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—E Descrzpz‘z'om and illustrations offlew species of fossils of Cerzomcmz'mz age UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1953 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 25 cents (paper cover) 231314—53 CONTENTS Page Abstract ___________________________________________________________________ 57 Historical sketch ____________________________________________________________ 57 Type section of the Pepper shale member _____________________________________ 58 Section of Pepper shale at Haunted Hill _______________________________________ 58 Systematic descriptions ______________________________________________________ 59 Pelecypoda ___________________________________________________________ 59 Gastropoda-__-___-__-__-____. _______________________________________ 64 Cephalopoda _________________________________________________________ 65 References _________________________________________________________________ 65 Index ______________________________________________________________________ 67 ILLUSTRATIONS Plate 13. Molluscan fossils, mainly from the Pepper shale .............. Following index In MOLLUSKS FROM THE PEPPER SHALE MEMBER OF THE WOODBINE FORMATION, McLENNAN COUNTY, TEXAS By LLOYD WILLIAM STEPHENSON ABSTRACT This paper records an assemblage of molluscan fossils from the Pepper shale member of the Woodbine formation at a locality known as Haunted Hill, 3.5 miles northwest of Moody, McLennan County, Texas. The assemblage includes the follow- ing four species previously described by me from the Woodbine formation: Anemia ponticultma?, Fulm‘a pingm‘s, Cyprimeria patella, and “C'orbuch” Mllensis. One species common to the Lewisville member of the Woodbine, previously described as Emogyra sp., is here given the new specific name, Emogym equil- lana. The following six additional new species are described: Breviarca (Sanoarca) spiritalis, Brem‘arca (Sanoarca) calcium, Cyclorisma nodana, Sinom'a lozoi, Parmicorbula moodiana, and Anohum wmbrana. One new variety, Turritalla shuleri pep- pemna, is described. The genus Baculites, not previously recorded from the Woodbine formation, is represented by a fragment of a small smooth unidentified species. The evidence afforded by this assemblage confirms the con- clusion that the Pepper shale member is the southward ex- tension of the Woodbine formation, and is probably the exten- sion of the Lewisville member of that formation. HISTORICAL SKETCH The stratigraphic unit from which the fossils de— scribed in this paper were, obtained was named the Pepper formation by W. S. Adkins in 1933 (Univ. of Texas Bull., 3232, pp. 239, .270, 417—422). This shale unit lies between the top of the Comanche series and the flaggy limestones and dark shales that form the base of the Eagle Ford shale (Gulf series) of Late Cre- taceous age. It crops out in a narrow belt extending from McLennan County, Texas, southward through Bell and Williamson Counties to Travis County. The unit had been known to earlier geologists, some of whom considered it a southward extending shale facies of the - Woodbine formation, and others a basal member of the Eagle Ford shale. The thickness of the unit in central McLennan County is 7 5 feet ‘or less, from which area southward it gradually becomes thinner and finally pinches out by overlap in Travis County south of Austin. ' My attention was first called to this unit by Mr. R. L. Cannon, in 1926 (oral communication). He informed me that he had traced a Woodbine-like clay Or shale from Hill County, where it was generally recognized as belonging to the Woodbine formation, southward through McLennan, Bell, and Williamson Counties, to the vicinity of Austin in Travis County. Acting on this information I visited localities in Hill, McLennan, and Bell Counties in 1926, and was able to confirm the presence of the Woodbine-like shale unit between the Buda limestone below and the undoubted Eagle Ford shale and interbedded flaggy limestone above. I did not at the time have an opportunity to restudy the section in Travis County. However, on a visit in 1928 I noted several feet of dark noncalcareous Woodbine- like clay forming the base of the section (mainly Eagle Ford) which intervenes between the Buda limestone below and the Austin chalk above on Bouldin Creek south of Colorado River at Austin. (Stephenson, 1927, pp. ‘3, 4.) In the Guide Book of the 1951 Field Trip of the East Texas Geological Society (Cretaceous of Waco, Texas Area, p. 155), the thickness of this clay, designated Pepper, is given by Adkinsand Lozo as 3.4 feet. ' The shale composing this unit is only meager-1y fos- siliferous and the few macrofossils heretofore found in it are poorly preserved. Adkins listed several genera of pelecypods, gastropods and ammonites, preserved as delicate impressions, from the type locality of the unit, but he did not consider them diagnostic of exact age (1933, p. 419). The late Helen Jeanne Plummer (in Adkins, 1933, pp. 419, 420) identified arenaceous Foraminifera from the lower part of the type section of the Pepper shale, belonging to the genera Ammobaculz'tes, Ammodiscus, and Reopham. She says, These species have no relation to those of the Grayson 0r Del Rio formations, but are similar to species in the Eagle Ford and other Upper Cretaceous faunal groups. I feel no hesitancy in referring this shale to the Upper Cretaceous series. 57 58 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 In 1946 Alfred R. Loeblich, J r., described eleven new species of arenaceous F oraminifera from the type 10- cality of the Pepper shale on Bird Creek, a small tribu— tary of Leon River, 4 miles east-northeast of Belton, Bell County, about 500 feet southeast of the Belton- Temple highway (U. S. 81). Loeblich says (pp. 132— 133) : Environment—The writer believes these sediments were de- posited in shallow waters of low salinity, because of the presence of abundant siderite and limonite concretions, the presence of large numbers of reworked calcareous forms, the absence of any indigenous calcareous Foraminifera in the type Pepper, the small size of the arenaceous species, the large amount of organic matter in some of the samples, and the limited mega- fauna, which consists only of mollusks and worms. 00rrelation.—The present fauna consists entirely of new species, and hence cannot settle the question of the correlation of the Pepper formation, but perhaps can be used for com- parison when the microfauna 0f the Woodbine is better known. At the time Loeblich’s paper was published he knew of the presence of this assemblage of arenaceous Forami- nifera only at the type locality of the Pepper shale, but he informs me that at a later time he found the same assemblage in the few feet of dark noncalcareous shale immediately overlying the Buda limestone in the Bouldin Creek section south of Austin. In recent years the age and stratigraphic relation— ships of the Pepper shale have been more critically studied in the Waco area (including parts of Bell, Mc- Lennan and Hill Counties) by Adkins and Frank E. Lozo, and the results of their field and laboratory studies are recorded in a paper published as part of “A Sym- posium for the 1951 Field Trip Sponsored by the East Texas Geological Society” (1951, pp. 101—161). It was my privilege to participate in this field trip, which was held May 3 to 5, 1951. The fossils described in the present paper (U. S. G. S. Coll. 23634) were collected by me during the course of the trip at the locality des- ignated “Haunted Hill” by Adkins and Lozo (pp. 134, 1315). As a result of their study-of the Pepper shale Adkins and Lozo interpreted this unit to be a southward ex- tending shale facies of the Lewisville member of the Woodbine formation. They summarize their conclu- sions in the following words (1951, p. 116) : In the area north of the Brazos, strata of porous and crumbly to friable, locally indurated, ferruginous sandstones occur, al- ternating with Pepper-type black, noncalcareous shales. South- ward these sandstones thin and disappear laterally Within the body of the shale formation, which is composed thereafter en- tirely of Pepper facies. This is a noncalcareous, noncarbonace- ous (except for ferrous carbonate and thin shells), black, locally glistening shale which contains pyrite and on the outcrop devel- ops gypsum, celestite, siderite, jarosite, and other minerals. The outcrop is poor in soil and vegetation. The fossil zonation is spotty, but at levels fossils occur, as shale ammonites at Alli.- gator Creek ; in fossiliferous limy seams at Haunted Hill. TYPE SECTION OF THE PEPPER SHALE MEMBER The type section of the Pepper shale member of the Woodbine formation is in small northwest-facing blufl's of Bird Creek, a small tributary of Leon River, 500 feet southeast of the Belton-Temple highway (U. S. 81) , about 4 miles east-northeast of Belton, Bell County. ‘ The member was named from nearby Pepper Creek. The following description of the type section is adapted from the description of the measured type section given ~ by Adkins and Lozo (p. 130). Section on Bird Creek, 1, miles east-northeast of Belton, Bell County, Teams Gulf series: Eagle Ford shale: Limestone, wavy—bedded, yellowish-brown, massive to platy and thin-bedded, with a thin bed of bentonite near the middle; locally with ammonites and other mol- lusks, in part fragmentary ________________ 2 + Shale, black, fissile, slightly calcareous, with abundant globigerinids and other she11s____ Unconformity Woodbine formation (Pepper shale member) : Shale, purplish-black, noncalcareous, with sele- nite crystals, and with yellow jarosite crys- tals, films and streaks in weathered parts of the shale; contains arenaceous foraminif- ers and thin nacreous shells and impres- sions of mollusks ________________________ 22,5 Shale, gypsiferous, with many euhedral sele- Feet 1. 5 nite crystals ______________________________ 0. 6 Clay, sandy, carbonaceous, gypsiferous, with qua1tz and phosphate pebbles, fish remains, lignitized wood and reworked Del Rio [sic] fossils ___________________________________ 0. 45 Unconformity Comanche series: Grayson marl (formerly Del Rio clay) : Clay, gray, massive, calcareous, fossiliferous__ 1. 5 Limestone, gray, soft, gritty, clayey __________ 0.3 Clay or marl, exposed downstream ___________ 25 + Total ____________________________________ 54 -|- SECTION OF THE PEPPER SHALE MEMBER AT HAUNTED HILL Haunted Hill is a low hill at the south end of a series of low hills, known as Moody Hills, about 3.5 miles northwest of Moody, McLennan County. The Pepper shale is well exposed in a bare area on the upper slope of Haunted Hill; neither the base nor the top of the member are seen in the exposure. The description of the shale given below is essentially a copy of that given by Adkins and Lozo, who measured in detail the beds exposed in the slope of the hill. They treated the shale as a formation of the Woodbine group. MOLLUSKS FROM THE PEPPER SHALE, WOODBINE, OF [TEXAS Incomplete section of Pepper shale exposed in the upper slope of Haunted Hill, 3.5 miles northwest of Moody, MoLennan County, Ted-a8 Woodbine formation (Pepper shale member) : Feet ‘ Shale, bluish-black, lustrous, jarositic and selenitic__ 10.0 Siderite concretions, small, reddish—brown, flat, oval- 0.1 Shale, bluish—black, lustrous, jarositic and selenitic__ 4.0 Siderite concretions _______________________________ 0. 2 Shale, bluish-black- -__ ___ 3. 5 Limestone shell breccia or coquina, finely sandy, gray, weathering yellowish, abundantly fossilifer- ous, mainly in the form of shell fragments, but in- cluding a few shells with features partly or nearly completely preserved; the fossils described in this paper were obtained from this bed _______________ 0.2 Shale, bluish-black ________________________________ 1.0 Siderite concretions, platy, dark reddish-brown _____ 0.1 Shale, bluish-black _______________________________ 2.0 Sideritic layer ____________________________________ 0.1 Shale, bluish-black _______________________________ 3.1 Total _____ 24. 3 Adkins and Lozo estimate that the base of the pre- ceding section as exposed lies about 5 feet above the contact of the Pepper shale with the underlying Gray- son marl (formerly Del Rio clay), and that about 10 feet of Pepper shale has been eroded from above the exposed section; this would indicate that the total thickness of the member in this area is approximately 4-0 feet. The fossils here described were obtained by careful preparation from pieces of the coquina limestone hast- ily collected during a short stop of the field party at Haunted Hill. It may be assumed that the possibilities of the fauna obtainable from this source were by no means exhausted. The following genera and species were identified from the coquina bed: Molluscan fossils identified from coquina limestone in Pepper shale at Haunted Hill, McLennan County, Texas [*Indicates previously described Woodbine species] Pelecypoda: Breoiarca (Sanoarca) spiritalis, n. s15. B. (8.) calciana, n. sp. Ostrea sp. Ewogyra aquillana, n. sp. *Anomia ponticnlana Stephenson? *Fulpic pinguis Stephenson *C’pprimeria. patella Stephenson Cyclorisma noddna, n. sp. Sinonia lozoi, n. sp. *“G'orbuld” hillensis (Stephenson) Parmicorbnla? moodlana, n. sp. Gastropoda: Turrttella shuleri pepperana, n. var. Anchura nmbrdna, n. sp. Cephalopoda : Bacnlites sp. (cf. B. gracills Shumard) Ammonoid fragment (may be Acanthoceras N eumayr or Metoicoceras Hyatt) 59 The molluscan fauna from the Pepper shale at the Haunted Hill locality, as listed above, seems to afford clear confirmatory evidence of the Woodbine age of the shale. The four previously described species, marked with an asterisk (*), are all recorded from the Wood- bine, and all the genera to which the new species (and one variety) are assigned are common to that formation. Of these, Brepiarea (Sanoanca) and Sinonia seem es- pecially significant as they are known only from the Woodbine. The new species, Ewogym aqnilldna, previ- ously described as Ewogym sp., and “Corbula” hillensz's (Stephenson), are recorded from the Lewisville mem- ber of the Woodbine, in southern Hill County in beds that are considered by Adkins and Lozo to be Woodbine representatives of the Pepper shale. Two previously described species, Anomia ponticulana and Fulpz'a pinguis, range throughout the Woodbine. The am- monite genus Baculites Lamarck has not heretofore been recorded from the Woodbine. The only previously de— scribed species in the list, restricted to the Lewisville member of the Woodbine is “Carbide” hillensis (Ste- phenson) , but the list affords no evidence opposed to the Lewisville age of the Pepper units. The new forms here described constitute additions to the fauna of the Woodbine formation recorded in my recent monograph (U. S. Geol. Survey Prof. Paper 242), and the present paper may be considered a sup- plement to it. SYSTEMATIC DESCRIPTIONS Class PELECYPODA Order PRIONODESMAGEA Family ARCIDAE Genus BREVIARCA Conrad, 1872 Subgenus SANOARCA Stephenson, 1953 Breviarca (Sanoarca) spiritalis Stephenson, n. sp. Plat 13, figures 1, 2 Shell small, subtrapezoidal in outline, strongly in- flated centrally, inequilaterial, subequivalve. Umbonal ridge distinct, subangular, a little rounded at the angle. Posterodorsal slope steeply descending, broadly exca— vated. Beaks prominent, strongly incurved, slightly opisthogyrate, situated slightly in advance of the mid— length. Anterior margin forming an obtuse subangle with the forward end of the area, regularly rounded below; ventral margin broadly rounded; posterior margin obtusely subangular below at end of umbonal ridge, nearly straight to slightly convex and inclined 'forward above, meeting the hinge line at an obtuse angle. Surface bears raised concentric lines that be- come stronger near the margins, and obscure radiating 60 SHORTE‘R CONTRIBUTIONS To GENERAL GEOLOGY, 1952 lirae that also become a little stronger near the margins, especially on the dorsal slopes. Dimensions of the holotype, a right valve: Length 9.1 mm, height 6.4 mm, convexity about 3 mm. Area long, subtriangular, straight on lower edge, ap- parently smooth; because ligamental cross striations seem to be absent, the species is referred to the subgenus Sanoarca Stephenson. Hinge long, narrow, straight on upper edge, widening a little and arching down slightly toward each end; teeth numerous, not sharply pre- served, transverse centrally, becoming slightly oblique toward the ends of the hinge. Inner surface not un- covered. 13’ re'viama (Sanaarca) fauccma Stephenson, is of comparable size, but the-present species is longer in proportion to height, and has a much longer, straighter and more delicate hinge. Breviarca (8.) faucmw is re- corded from the Euless and Lewisville members of the Woodbine formation. The abundant B. (8.) habita Stephenson resembles B. (8.) spiritalis in shape but is smaller and has sharper concentric and radiating lirae. Brervz'arca (8.) .caloz'ama, n. sp., is more elon- gated, more sharply pointed posteriorly, has a stronger development of concentric growth ridges, and more obscure radiating lines. TypeS.—Holotype, U.S.N.M. 108336; 15 unfigured paratypes, U.S.N.M. 108337; all from the Pepper shale member of the Woodbine formation, at the Haunted Hill locality. I Breviarca (Sanoarca) calciana Stephenson, n. sp. Plate 13, figures 3, 4 Shell small, elongate-subtrapezoidal in outline, in- flated, inequilateral, subequivalve, broad in umbonal region; umbonal ridge long, subangular, concave up- ward in trend; posterodorsal slope long, descending, broadly excavated, deepest near and parallel to the umbonal ridge; beaks moderately prominent, incurved, slightly opisthogyrate, situated about two—fifths the length from the anterior end; anterior margin regu- larly rounded, ventral margin very broadly rounded, posterior extremity rather sharply subangular at end of umbonal ridge, posterior margin nearly straight to slightly convex, inclined strongly forward, meeting the hinge line at a wide obtuse angle. Surface smooth in the umbonal region, but away from the beak the growth lines increase in coarseness and toward the margins form round—crested growth ridges spaced about four to the millimeter'radially. . Dimensions of the holotype, a left valve: Length 11.6_ mm, height 7.3 mm, convexity 3.5 mm. Area greatly elongated, subtriangular, apparently smooth, showing neither transverse nor chevron-shaped ligamental grooves. Hinge long, narrow, straight on upper edge, widening slightly and arching down a little at the ends; teeth numerous, central ones trans— verse, those on the wider ends slightly oblique. This species resembles Brem’arca (Sanaarea) spirit- alz's in size but is more elongated, more sharply pointed at the posterior end, has a coarser development of con- centric growth ridges toward the margins, and has practically no radial sculpture. Typ68.—Holotype, a left valve, U.S.N.M. 108338; 1 figured paratype, U.S.N.M. 108339; 10 unfigured para- types, U.S.N.M. 108340. Superfamily OSTRACEA Family OSTREIDAE Genus OSTREA Linné, 1758 Ostrea sp. Two small water—worn specimens of Ostrea Linné are present in the collection from Haunted Hill. One of them is subcircular in outline, relatively thick and measures 10mm in length. The other is subovate in outline, shows the hinge rather obscurely, and is 13 mm long and 15 mm high. These may be young examples of Ostrea solem’scus Meek, a common species in the Woodbine formation. U.S.N.M. 108341. Genus EXOGYRA Say, 1820 Exogyra aquillana Stephenson, n. sp. Plate 13, figures 5—8 Ewogym sp. Stephenson, U. S. Geol. Survey Prof. Paper 242, p. 78, pl. 18, figs. 4—6, 1953. This species was described and figured without a specific name, as indicated above. The shells, which are present in great numbers at the Aquilla Creek 10- cality, were thought to be a .depauperate assemblage of some larger species. Four shells found at the Haunted Hill locality seem to be conspecific with the Aquilla Creek shells, and to indicate that the species has a rather wide geographic range, and is of value as an index fossil. It seems desirable therefore for con- venience of reference to give it a specific name. The available material includes only left valves. One internal mold of a small Emogym in a matrix of fer- ruginous sandstone of the Euless member of the Wood- bine formation on State Highway 183, within 1.2 miles west—southwest of Euless, Tarrant County, Texas (U.S.N.M. 105227), probably belongs to this species. This specimen was described, but not figured, on page 78 of Professional Paper 242. i The largest specimen (a paratype) measures about 23 mm in its greatest dimension (height). Mest of the MOLLUSKS FROM THE PEPPER shells are less than 17 mm in height. The shells are smooth, strongly convex, and narrow in the umbonal region. The beak is sharply twisted at the tip except as it may be modified by the scar of attachment. The shells show individual variations in form. The speci- mens consist of internal molds to which some shell sub- stances adheres. Dimensions of the holotype : Length 11 mm, height 15 mm, convexity 6 mm. The adductor scar as seen impressed on the internal mold of one paratype is of moderate size, subcircular, situated a little below midheight and a little back of midlength. Types.——Holotype, U.S.N.M. 105225a; 1 figured para- type, U.S.N.M. 105225b; 53 unfigured paratypes, U.S.N.M. 1052265 all from Aquilla Creek at base of Lewisville member of Woodbine formation, 1.2 miles east of Aquilla, Hill County, Texas (U.S.G.S. Coll. 19018). One figured paratype, U.S.N.M. 108342; 3 unfigured paratypes, U.S.N.M. 108343; from the Pep- per shale'member of the Woodbine formation, 11 feet above base, at Haunted Hill, on the Paul Alexander farm, about 31/2 miles northwest of Moody, McLennan County, Texas (U.S.G.S. Coll. 23634). One unfigured paratype, U.S.N.M. 105227; from Euless member of Woodbine formation onState Highway 183, within 1.2 miles west-southwest of Euless, Tarrant County, Texas (U.S.G.S. Coll. 19040). Superfamily ANOMIAOEA Family ANOMIIDAE Genus moms (mnné, 1758) min“, 1776 Anomia ponticulana Stephenson? Anom/ia ponticulana Stephenson, U. S. Geol. Survey Prof. Paper 242, p. 81, pl. 20, figs. 1—4, 1953. The Haunted Hill locality yielded six small poorly preserved specimens of Anomia that probably belong to A. ponticulana Stephenson. The typical fine radiat- ing lirae of that species are wanting, but the outer shell layer of the specimens appears to have been worn or peeled off before preservation. Besides, even on the "typical shells, the radiating lirae are usually obscure or wanting and the largest of these six specimens is only 12 mm in length. They show some variations in form, but all are subcircular left valves of low convexity. U.S.N.M. 108344. 231314—53—2 SHALE, WOODBINE, or TEXAS 61 Order TELEODESMACEA Superfamily CYRENACEA Family CYRENIDAE Genus FULPIA Stephenson, 1946 Fulpia pinguis Stephenson Fulm‘a pingm‘s Stephenson, Jour. Paleontology, v01. 20, No. 1, p. 68, figs. 1—4, 1946. Fulm‘a, ptnguis Stephenson, U. S. Geol. Survey Prof. Paper 242, p. 97, pl. 23, figs. 1—4, 1953. Fulpz'a pingm's Stephenson is represented in the Haunted Hill collection by 5 poorly preserved but identifiable specimens. The shape, surface features, and characters of the partly preserved right and lefthinges agree well with the types from the Lewisville member of the Woodbine formation on Sheep Creek in Fannin County, Texas. The largest specimen from Haunted Hill, a left valve, measures: Length about 24 mm, height about 21.5 mm, convexity about 9.5 mm. The species ranges throughout the full thickness of the Woodbine formation. U.S.N.M. 108345. Superfamily vENERACEA Family VENERIDAE Genus CYPRIMERIA Conrad, 1864 Cyprimeria patella Stephenson Cyprimerta patella Stephenson, U. S. Geol. Survey Prof. Paper 242, p. 108, pl. 27, figs. 12—18, 1953. The collection from Haunted Hill includes 11 poorly preserved, and in part incomplete, specimens of 031m- maria patella Stephenson, 4 right valves, 6 left valves, and one small shell with both valves intact. These specimens range from 8.5 mm to about 40 mm in length. The holotype, a shell 52 mm long is from the Templeton member of the Woodbine formation near old Slate Shoals on Red River, 8 miles east of Arthur City, Lamar COunty, Texas. The shells from Haunted Hill do not differ from the types in any essential feature. The species is not recorded from the Lewisville member of the Woodbine formation, with which the Pepper shale has been correlated. U.S.N.M. 108346. Genus excromsm Dan, 1902 Cyclorisma nodana Stephenson, n. 51). Plate 13, figures 9—12 . This is a common species at Haunted Hill, though, as is usually true of fossil shells in coquina, most of the 62 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 specimens are poorly preserved. Several of them are in fair condition. Shell small, thin, subcircular in outline, slightly in- equilateral, equivalve, moderately convex, greatest in- flation above the midheight. Beaks rather prominent, incurved, prosogyrate, approximate, situated a little in advance of the midlength. Lunule not excavated but distinctly outlined by a narrow groove; escutcheon wanting. Surface with numerous, regularly spaced, round crested, concentric ribs, numbering 4 to the mil- limeter in the radial direction on the adult stage. Dimensions of the holotype, a left valve: Length 13 mm, height 12.5 mm, convexity 5 mm. The largest specimen in the collection is about 15 mm long. Ligament external, about 4.5 mm long in the holo- type; ligamental groove sharply incised, nymph nar- row, plain. Hinge with three cardinal teeth in each valve; lower margin of hinge sinuous, convex inward below the beak, concave outward back of the beak; laterals wanting. The cardinal teeth are not very sharply preserved in available material. In the right valve the anterior cardinal tooth is small, short, oblique forward; middle tooth nearly direct inward, apparently thick, probably covered with secondary calcite; poste- rior tooth oblique rearward, long, subtrigonal, prob- ably bifid; anterior and middle teeth separated by a narrow, deep socket, and middle and posterior teeth by a long oblique trigonal socket of moderate depth. In the left valve the anterior and middle cardinal teeth unite at the top to form an inverted V the limbs of which are separated by a trigonal socket; the posterior tooth is long, narrow, and very oblique and is separated from the middle tooth by a long, wide, oblique, trigonal socket. The pallial line is well back from the margin and the pallial sinus, as obscurely seen on the internal mold of one of the paratypes, is V—shaped, moderately deep, and points toward the beak. In form and in hinge characters this species is very muchlike the genotype, Ug/clorz'sma carolinemis (Con- rad), from the Snow Hill marl member of the Black Creek formation at Snow Hill, North Carolina, but the individuals average one-third or less in size. This species resembles Cyclorz'sma orbimdata Ste- phenson from the Templeton member of the Woodbine formation in Lamar County, Texas, and is about the same size, but it is proportionately a little longer; the concentric surface ridges are stronger and more regular, and a lunule is present, outlined by a distinctly impressed line. Specimens that have the hinge covered or missing might easily be mistaken for a representa- tive of the genus Fulpia Stephenson. Types.—Holotype, U.S.N.M. 108347 ; 2 figured para- types, U.S.N.M. 108348; 20 unfigured paratypes, U.S.N.M. 108349. Genus SINONIA Stephenson, 1953 Sinonia lozoi Stephenson, n. sp. Plate 13, figures 13—15 This species is represented in the collection by one apparently adult left valve whose margin is broken away in places, and by four fragments of young in- dividuals, two left and two right valves, all with beaks preserved; the large left valve (holotype) is complete enough to show outline, form, surface features, and hinge. One fragment, a right valve, shows a nearly complete, partly worn hinge. . Shell of medium size, subovate-elongate in outline, thin, compressed, strongly inequilateral, equivalve. Beaks moderately prominent, incurved, prosogyrate, situated about‘one-third the length of the shell from the anterior end. Lunule and escutcheon wanting. Anterodorsal margin steeply descending, broadly arched; anterior margin rounded less than a semicircle; ventral margin very broadly rounded; posterior margin less sharply rounded than the anterior margin, fullest below, slightly subtruncate in the adult; posterodorsal margin long, broadly arched, gently descending. Sur- face showing only unequally developed incremental lines and low, narrow, irregular ridges. Dimensions of the holotype: Length 32.5 mm, height about 23 mm, convexity about 6.5 mm. Ligament external, opisthodetic, groove narrow, deeply impressed, nymphs long, narrow, and rather prominent. Three cardinal teeth in left valve; anterior and median cardinals about equal in size and joined at upper ends to form an inverted V inclosing a deep trigonal socket; anterior cardinal strong, slightly bifid, directed inward and slightly forward; middle tooth simple, directed inward and slightly backward; poste— rior tooth long, strongly oblique rearward paralleling the nymph, weak, separated from the middle cardinal by a long, wide, and deep trigonal socket; in front of the anterior cardinal is a moderately deep trigonal socket opening into a shallow lateral channel that ex- tends forward about 5 mm. Features of the inner sur- face not uncovered. The hinge of the right valve is nearly complete in a shell fragment that shows some- what worn nymph and teeth. The anterior cardinal tooth is of medium strength and is separated from a. strong trigonal middle tooth by a narrow deep socket; the posterior cardinal tooth is long, narrow, bifid, strongly oblique; it is separated from the middle tooth by a long, narrow, trigonal, oblique socket and from the nymph by a long, narrow socket. MOLLUSKS FROM THE: PEPPER Although the holotype of this species is about the size of the holotype of Sinania levis Stephenson (the type species of the genus, from the Woodbine forma- tion) , the former is higher in proportion to the length, has a heavier hinge plate, a slightly longer ligament, and a somewhat more prominent umbonal region. Type8.—-Holotype, U.S.N.M. 108350; 1 figured para- type, U.S.N.M. 108351; 3 unfigured paratypes, U.S. N.M. 108352. Named in honor of Frank E. Lozo. Superfamily MYACEA Family CORBULIDAE Genus CORBULA Lamarck,‘ 1799 “Corbula” hillensis (Stephenson) Plate 13, figures 16—20 ‘Pm-micorbulu? hillensis Stephenson, U. S. Geol. Survey Prof. Paper 242, p. 133, pl. 33, figs. 13-15, 1953. The holotype and paratypes of this species are in- ternal and external molds in fine ferruginous sandstone from a roadside exposure 3 miles northeast of Whitney, Hill County, Texas; the collection was made by Roy T. Hazzard about 1941. The species is represented at the Haunted Hill locality by many shells, mostly worn or incomplete, but a few are nearly complete and show the form, surface features, and hinges with only minor defects. Both right and left valves are present, but the two valves are not found together as one individual. No features indicating the presence of an accessory siphonal plate back of the terminus of the left valve can be detected in any of the shells, for which reason the species is here treated as belonging to “Carbula”, as this name is used in a broad sense; it falls definitely within the family Corbulidae. The species is here re- described on the basis of the more complete specimens now available. ~ Shell of medium size, subtrigonal in outline, strongly inflated in the umbonal and anterior parts, narrow and strongly constricted in the posterior part, inequilateral, inequivalve. Beaks very prominent, incurved, proso- gyrate, situated a little in advance of the midlength on the right valve, nearly central on the left valve; right valve more strongly inflated than the left and beak more strongly incurved. Anterodorsal margin steeply de- scending, broadly arched; anterior margin sharply rounded below the midheight; ventral margin broadly rounded becoming slightly concave near the posterior extremity; posterior margin short, subtruncated, in- clined slightly forward; posterodorsal margin gently inclined, nearly straight or slightly sinuous. Surface of right valve covered with pronounced, irregular concentric ribs that increase in coarseness outward to- ward the margins; these ribs end rearward a little short 63 SHALE, WOODBINE, OF TEXAS of the posterodorsal slope. Surface of left valve nearly smooth, or with weakly and irregularly developed con- centric ribs. g Dimensions of the plesiotype (right valve) shown in plate 13, figure 20: Length 13.1 mm, height 9 mm, con- vexity 4.5 mm. Hinge of right valve with one cardinal tooth of medium size below the beak; back of the tooth is a deep resiliary pit; in one plesiotype the tooth appears to be somewhat worn. Hinge of left valve has a rather short, somewhat worn resiliary platform which is di- rected obliquely rearward and slopes steeply forward toward a deep trigonal cardinal socket. Internal molds show that the anterior adductor scar is small and sub- ovate, and the posterior adductor small, elongate, and seated on a raised platform. Types.—Holotype, U.S.N.M. 105555; paratypes, U.S.N.M. 105556 (figured) and 105557. Plesjotypes from the Haunted Hill locality (U.S.G.S. Coll. 23634; U.S.N.M. 108353a—c) ; numerous unfigured examples . from Haunted Hill, U.S.N.M. 108354. Occurrence—Holotype and paratypes, northeast- southwest road, 3 miles northeast of Whitney, Hill County (U.S.G.S. Coll. 19020). Three plesiotypes and numerous other specimens from Haunted Hill, 31/2 miles northwest of Moody, McLennan County (U.S.G.S. Coll. 23634). Ravine east of road to Ghol- son, 2.8 miles east of Gholson (U.S.G.S. Coll. 14587), and Elm Creek, 2 miles southwest of Wiggins, 6.5 miles southwest of the town of West, McLennan County (U.S.G.S. Coll. 23635). Genus PARMICORBULA Vokes, 1944 Parmicorbula? moodiana Stephenson, n. sp. Plate 13, figures 21—23 Shell small, subtrigonal in outline, strongly inflated in the umbonal area, narrowing and becoming strongly constricted posteriorly,.inequilateral, inequivalve. The posterodorsal slope forms a broadly excavated band crossed only by growth lines, bounded by a subangular umbonal ridge, and extending radially to the truncated terminus. Beaks very prominent, incurved, proso- gyrate, situated at or a little anterior of the midlength. Anterodorsal and anterior margin rather sharply rounded below the midheight; ventral margin broadly rounded. Posterior margin of right valve short, trun- cated, inclined forward, meeting the posterodorsal mar- gin at an obtuse angle; the latter margin gently inclined, nearly straight or a little upturned at the rear. Pos- terior margin of left valve bluntly subangular below the midheight, rounding upward into the posterodorsal margin. The two valves were not seen together but the 64 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 narrow, flattish, posterior extension of the right valve, compared with the shorter blunt extremity of the left valve suggest that there was in the living shell an acces- sory siphonal plate at the terminus of the latter; this plate would be lost when the two valves became sepa- rated. The existence of this plate is also suggested by the presence of a radial groove on the outer surface of the posterior extension of the right valve, possibly re- flecting a radial ridge on the inner side of this extension ; on the typical Parmz'corbula a ridge of this sort on the inner side of a posterior projection stands opposite a similar ridge on the inner side of the characteristic accessory plate, the function of the two ridges being to separate the two siphons where they pass out rearward. On the right valve the umbonal part of the'outer sur— face, including one-third to one-half the total surface, is smooth; the rest of the surface in front of the umbonal ridge is covered with small, closely spaced concentric ridges, 'which increase in coarseness toward the outer margin, where they number 3 or 4 to the millimeter in the radial direction. The surface of the left valve shows only obscure growth ridges interrupted on some shells by an occasional groove marking a resting stage in growth. Dimensions of the holotype, a right valve: Length 5 mm, height 3.6 mm, convexity about 1.5 mm. A larger right valve (a paratype) measures: Length about 5.5 mm, height 4 mm, convexity about 2 mm. The left valve is slightly shorter than the right. Hinges and internal features not well enough uncov- ered for description. , The species resembles Parmz'corbula comelz’ana Stephenson, but it is smaller, not quite so plump, and less coarsely sculptured. Types.——Holotype, a right valve, U.S.N.M. 108355; 2 figured paratypes, U.S.N.M. 108356; unfigured para- types, 3 left valves and 5 right valves, U.S.N.M. 108357. Class GAsrnoronA Order CTENOBRANCHIATA Family TURRITELLIDAE Genus TURRITELLA Lamarck, 1799 Turritella shuleri pepperana Stephenson, n. var. Plate 13, figure 24 The coquina limestone in the Pepper shale at Haunted Hill yielded several fragmentary specimens of a noded form of Tumm'tella Lamarck, representing early stages of growth, all poorly or incompletely preserved. They are closely related to T. shuleri Stephenson from the Lewisville and Templeton members of the Woodbine formation and are here treated as a variety of that species. The shells show some variation in details of sculpture, but the description is based mainly on the holotype. The shell is high-turreted; the sides of the whorls are nearly flat and are separated by a moderately deep . sutural depression. Each whorl bears 4 primary noded - spirals; the uppermost primary is the smallest of the four and bears the most numerous small, closely spaced nodes; the second primary below the suture is largest and bears the coarsest and most prominent nodes; the two lowest primaries are of about equal strength and bear nodes of. intermediate size and prominence. Between the second and third primary below the suture is a rib of medium strength that may be classed as a secondary spiral; it is neatly ornamented with numer- ous, small beadlike nodes; between the lowermost primary and the lower suture are two nearly smooth spirals of about secondary strength. All the other intermediate primaries are very small (tertiaries) and are more or less clearly ornamented with very tiny nodes; they number one to three in the interspaces be- tween the primaries and secondaries. The periphery is subangular and the flatttish base is covered with fine, rather obscure spiral lirae. The diameter of the largest whorl of the holotype is 6 mm. Because of the individual differences in the spiral sculpture of the typical Turm'tella shulem' the sculpture of this variety cannot satisfactorily be compared with ,it in detail; in general, however, the former possesses thicker and stronger primary spirals, and these spirals bear much coarser nodes, especially the two upper ones, than is true of the latter at the same stage of growth. Compared with the typical T. shwlem' the base of this variety appears to be flatter, the periphery more angu- lar, and the suture a little more deeply impressed. Types.——Holotype U.S.N.M. 108358; 10 unfigured paratypes, U.S.N.M. 108359. Family APORRHAIDAE Genus ANCHURA Conrad, 1860 Anchura umbrana Stephenson, n. sp. Plate 13, figures 25—30 Shell rather small for the genus, high-turreted, with spiral angle of about 30 degrees. Protoconch not pre- served. Whorls 6 or 7, gently convex on the side, the larger whorls ornamented with axial ribs and spiral lirae; on the penultimate whorl the axials are small, closely crowded, and number at least 22; they are strongly oblique and sinuous in trend, being slightly convex forward below, broadly concave forward above, bending strongly forward just below the suture; the spiralsare small, obscure centrally, and become a little stronger toward the sutures both below and above. On MOLLUSKS FROM THE PEPPER the body whorl the axials extend well down the basal slope, becoming weaker toward the lip; they are broadly convex forward in trend except near their upper ends where they bend forward to the suture. The spirals are obscure on the inflated part of the body whorl but become stronger above, the uppermost just below the suture being relatively coarse; about 10 spirals are pre- sent on the basal slope, the upper 4 or 5 being weak to obscure, and the lower 5 or 6 relatively strong; low rounded nodes mark the intersections of the axials with the stronger spirals. The aperture is ovate-elongate. The outer lip is expanded and winglike but is poorly preserved in the available material. A rather obscure impression on one paratype (pl. 13, fig. 29), and one wing broken from its parent shell (pl. 13, fig. 30) indi- cate the presence of one thick, winglike, upturned pro- jection ; the latter figure shows the interior of the broken wing. The inner lip forms a rather broad band of callus over the parietal wall. - Dimensions of the holotype, an incomplete shell: Diameter, exclusive of the expanded lip, about 11.5 mm, height 24+ mm. ’ Types.—-Holotype, U.S.N.M. 108360; 4 figured para— types, U.S.N.M. 108361 ; 30 or more unfigured paratypes, mostly poorly preserved, U.S.N.M. 108362. Order OEPHALOPODA Family LYTOCERATIDAE Genus BACULITES Lamarck, 1799 Baculites sp. Plate 13, figure 31 The genus Baculz'tcs Lamarck (sensu lato) is repre- sented in the collection from Haunted Hill by one frag- ment which apparently pertains to a small smooth slender species having a broadly ovate cross section. The specimen is slightly crushed on one side but its dimensions are approximately as follows: Length 13 +mm, greatest dorso—ventral diameter 5.8 mm, great- est transverse diameter 5 mm; at the small end the dorso-ventral diameter is about 5 mm and the transverse diameter about 4.6 mm. Sutures are obscurely recog- nizable on the crushed side of the fragment where the shell has been partly peeled ofl", and one incomplete septum is uncovered at the small broken end of the conch. U.S.N.M. 108363. This short, incomplete specimen of Baculz'tes appears to be smooth, lacking the oblique cross undulations that characterize a similar species common in the Metoico- cams whitei zone in the Eagle Ford shale 50 or 60 feet above its base in Texas. This species from the Eagle Ford formation is usually referred to B. gracilz's B. F. Shumard, but is now cOnsidered [by J. B. Reeside, Jr. 65 SHALE, WOODBINE, OF TEXAS and others as belonging to the genus Sciponoceras Hyatt. In this connection attention is called to Shumard’s statement that his species was found on Shawnee Creek in Grayson County, Texas (1860, p. 596). The only creek by this name shown on present available maps of Grayson County is northwest of Deni- son in a drainage basin that lies entirely within an area underlain by strata of the Comanche series. Shumard did not illustrate the species, his type material is pre- sumed to be lost, and an identification can not safely be made from his published description. If the Shawnee Creek on which G. G. Shumard (brother) collected'the types of Baculites gracilz’s is the same as the creek cur- rently known by that name there is reason to doubt that the species of Sciponoceras associated with Metoicocems whitez’ Hyatt in the stratigraphically higher Eagle Ford shale is correctly referable to Batmlz'tes graoilis Shu— mard; it probably needs a new specific name. No representatives of Baculites are recorded in my recent (1953) treatise on the larger invertebrate fossils of the Woodbine formation of Texas. Adkins (1920, p. 74) describes a species, Baculz'tes commhensz’s, from the Pawpaw formation (upper part of Comanche series), near Fort \Vorth, Texas. This species he later “referred tentatively to Oyrtochilus Meek (1928, p. 207 ) . This is about the lower limit of the known stratigraphic range of Bacuh'tes (sensu lato). Family COSMOCERATIDAE? Genus? , Ammonoid fragment (Acanthocerasz or Metoicoceras?) The coquina bed at Haunted Hill yielded one small scarcely identifiable ammonoid fragment that may be- long to the genus Acanthocems Neumayr, or possibly to Metoicocems Hyatt. The specimen shows two lateral radiating ribs, each with a fairly high elongated node on the umbilical shoulder; between these two ribs is part of a shorter rib, and part-of another short rib appears to the left of the three ribs. U.S.N.M. 108364. REFERENCES Adkins, W. S., 1920, The Weno and Pawpaw formations of the Texas Comanchean: Texas Univ. Bull. 1856. 1928, Handbook of Texas Cretaceous fossils: Texas Univ. Bull. 2838. 1933, The geology of Texas; Pt. 2, The Mesozoic systems in Texas: Texas Univ. Bull. 3232,.pp. 239—518. and Lozo, F. E., 1951, Stratigraphy of the Woodbine and Eagle Ford, Waco area, Texas, in Adkins, W. S., and others, 1951, The Woodbine and adjacent strata of the Waco area of central Texas: Fondren Science Series 4 (Dallas), pp. 101—164, 6 pls. Loeblich, A. R., Jr., 1946, Foraminifera from the Pepper shale of Texas: Jour. Paleontology, vol. 20, no. 2, pp. 130—139, pl. 22, 3 figs. 66 SHORT’E‘R CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 Lozo, F. E., 1951, Stratigraphy of the Woodbine and Eagle Ford, Waco area, Texas, m Adkins, W. S., and others, 1951, Stratigraphic notes on the Maness (Comanche Cretaceous) shale: Fondren Science Ser. 4 (Dallas), pp. 65—92, 7 figs. 2 pls. \ Plummer, Helen Jeanne, 1933, cited in Adkins, W. S., The geol- ogy of Texas; Pt. 2, The Mesozoic systems in Texas: Texas Univ. Bull 3232, pp. 419—420. Shumard, B. F., 1860, Descriptions of new Cretaceous fossils from Texas: Acad. Sci. St. Louis Trans, vol. 1, pp. 590—610. Stephenson, L. W., 1927, Notes on the stratigraphy of the Upper Cretaceous formations of Texas and Arkansas: Am. Assoc. Petroleum Geologists Bull., vol. 11, no. 1, pp. 1—17. 1953, Larger invertebrate fossils of the Woodbine forma- tion (Cenomanian) of Texas: U. S. Geol. Survey Prof. Paper 242. INDEX [Italic numbers indicate descriptions] ’ Page Pug. Acanthoceras __ 59, 65 Historical sketch —————————————————————————————————————————— 57 Adkins, W. 8., and Lozo, F. E., quoted ________________________ 58 . _ _ Anchum umbrn/ml 59' 6 4’ D}. 13 161118, .Smoma _____________ 63 Anom/ia ponticulana _ _ 59, 61 Loeb'hch‘, A'. R., J12, quotgd ________________________________ 58 aqm‘llana, Ewagym ___ 59’ 60,1)1. 13 lozm, Swarm 59, 62, pl. 18 Baculites comanchemis __- ___ 65 Metoicocer'as ““ 59' 65 gracilis 59, 65 Whit“ """""" " ‘ """ 65 SD ____ 65 moodiana, Parmicorbula- nu 59! 63, 131- 13 Brev'larca (Samarca) calcium ________________________ 59, 60, pl- 13 ”MM", Cyclom‘sma _____ _ ______ =59, 61, p], 13 fauna/nu 60 J habita- 60 orbiculata, Cyclorlsmn 62 spiritaliL 59, 60, pl. 13 Ostrea solem‘scus--- \ 60 . sp _- 59, 60 calciana, Bremarca (Sanoarca) ________________________ 59, 60, pl. 13 _ carounensis, Cyclorisma ______ ' 62 Parmicorbulu cormh‘nmn ______ 64 ' Comanche series __ _ 58 hillensls _______ 63 comanchensis, BaculiteL--- _ 65 moodiana _______________________________________ 59, 63, pl- 13 Oarbula hillensis _.. R9, 63, pl. 13 patella) Cyprimeria__ 59, 61 cornelitma, Parmicorbula 64 Pepper shale, sections ______ 58—59 Cyclorisma caroldnensis" 62 pingu’is, Fulm'a _____ _ y 59, 61 nodtma ‘19, 61, pl. 13 ponticulana, Anemia" 59, 61 orbiculatn __ 62 Plummer, H. J., quoted _____ 57 prrimeria patella 59, 61 . Oyrtochilus - 65 ReferenceS- 65 Del Rio clay 58 (Sanaarca) calciana, Breviarca ________________________ 59, 60, pl. 18 faucana, Brem‘arca ____________________________________ 60 Eagle Ford shale _________________________________________ 58 habita, Breviarca _____ 60 Ewogyra aqulllann 59, 60, pl. 13‘ spiritalis, Brevlarm 59, 60. 111- 13 sp ___- 60 Sciponoceras 65 ' shah-I — faucqna, Breviarca (Sanoarca) _____________________________ 60 fifiéizs’fifffiifm 58 :2 “”1"". I 62 smoma levis 63 WW“ “ 59. 61 10201 ___ 59, 62, p1.13 i ‘ solemscus, Ostrm _ 60 32:33:; figgflttea ' 59’ g: spiritah‘s, Bre'viarca (“ ca) 59, 60, pl. 13 Gulf “Fri“ 58 Turritella shulem‘ _____ 64 ham-m, Bremarw (a w) 60 shulem‘pepperana ————————————————————————————————— 59, 64,1)1- 13 Haunted Hill, molluscan fossils _____________________________ 59 umbrana Anchura- 59 6 4 pl 13 section 58—59 .v V , , , hillensis, Corbuln ‘9, 63, pl. 13 whitei, Metoicoceras 65 Parmicorbula ___- 63 Woodbine formation _______________________________________ 58, 59 67 PLATE 13 PLATE 13 [With the exception of the holotype and one paratype of Emayra aquillana, n. sp. all the specimens illustrated on this plate are from the Pepper shale at Haunted Hill, FIGURES 1, 2. 3, 4. 9-12. 13—15. 16—20. 21—23. 24. 25—30. 31. MoLennan County, Texas. U.S.G.S. call. 23834) Brem‘arca (Sa'noarca) spiritulis, n. sp. (p. 59). Side and dorsal views, X 4, of the holotype (a right valve) U.S.N.M. 108336. Brem'arca (Sanoarca) calciana, n. sp. (p. 60). 3. Side View, X 4, of the holotype, (a left valve), U. S N. M. 108338. 4. Hinge view, X 4, of a paratype, (a left valve), U. S. N. M. 108339. The numerous small transverse teeth are only obscurely shown on figure 4.. . Exogyra aquillana, n. sp. (p. 60). 5, 6. Side and front views, X 2, of the holotype, (a left valve), from Aquilla Creek, 1. 2 miles east of Aquilla, Hill County, Texas, U. S. N. M. 105225a. (From U. S. G. S. coll. 19018.) 7. Side view, X 2, of a paratype, (a left valve), from the same source, U.S.N.M. 105225b. 8. Side view, X 2, of a paratype, '(a left valve), from the Pepper shale at Haunted Hill, U. S.N.M. 108342. Cyclorisma nodana, n. sp. (p. 61) 9,10. Side and hinge views, X 3, of the holotype, (a left valve), U. S. N. M. 108347. 11,12. Hinge views, X 3, of 2 paratypes, (right and left valves), U. S. N M. 108348. Sinom'a lozm}, n. sp. (p. 62). 13, 14. Side and hinge views, X 1%, of the holotype, (a left valve), U.S.N.M. 108350. 15. Incomplete hinge, X 3, of a paratype, (a right valve), U.S.N.M.108351. “Corbula” hillensis Stephenson (p. 63). 16, .17. Side and. hinge views, X 2, of a. plesiotype, (a right valve), U.S.N.M. 1083539... 18, 19. Side and hinge views, X 2, of a plesiotype, (a left valve), U.S.N.M. 108353b. 20. Side view, X 2, of a plesiotype, (a right valve), U.S.N.M. 108353c. Parmicorbula moodiana, n. sp. (p. 63). 21. Side view, X 4, of the holotype, (a right valve), U.S.N.M. 108355. 22. Side view, X 4, of a paratype, (a right valve), U.S.N.M. 108356. 23. Side view, X 4, of a paratype, (a left valve), U.S.N.M. 108356. Turr'itella shuleri pepperana, new var. (p. 64). The holotype, X 3, U.S.N.M. 108358. Anchura. umbrana, n. sp. (p. 64). 25, 26. Front and back views, X 2, of the holotype, U.S.N.M. 108360. 27—29. Views, X 2, of 3 paratypes, U.S.N.M. 108361. 30. Interior view, X 2, of an expanded outer lip of a paratype, U.S.N.M. 108361. Bacuh'tes sp. (p. 65). A fragment, X 2, showing smooth outer surface, U.S.N.M. 108363. U. I. COVIRIIII‘I’ PRIII‘I'Illfl OFFICE: I958 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE 13 26 MOLLUSCAN FOSSILS MAINLY FROM THE PEPPER SHALE MA: t ' Conodonts of the Barnett Formation of Texas 4- GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—F Conodonts of the Barnett Formation of Texas By WILBERT H. HASS A SHORTER CONTRIBUTION TO GENERAL GEOLOGY, 1952, PAGES 69—94 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—F UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON :1953 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 55 cents (paper cover) CONTENTS Page Abstract ______________________________________________________________________________________________________ 69 Introduction __________________________________________________________________________________________________ 69 Age of the Barnett formation ..................................................................................... 69 Conodont faunal zones _________________________________________________________________________________________ 70 Lower conodont faunal zone______-____-__-_____-_-______-----______--_---___-_-_---------_-----‘_ ____________ 71 Upper conodont faunal zone _________________________________________________________________________________ 71 Measured sections _____________________________________________________________________________________________ 73 Locality register ................................................................................................ 76 Systematic descriptions- - _ _ _ _ - _ _ _ - - _ 1 ........................................................................... 77 References cited ............................................................................................... 90 Index ________________________________________________________________________________________________________ 93 ILLUSTRATIONS ‘ Page PLATES 14—16. Barnett formation; upper conodont faunal zone ____________________________________________ Follow index FIGURE 4. Map showing localities at which conodonts of the Barnett formation were collected ......................... 75 TABLE Page TABLE 1. Distribution of conodont species in the upper faunal zone of the Barnett formation- ____________________ Facing 72 III CONODONTS OF THE BARNETT FORMATION OF TEXAS , BY WILBERT H. HAss ABSTRACT The Barnett formation (Mississippian) of the Llano region, Texas, contains two conodont faunal zones. The upper of these two zones is believed to be restricted to that portion of the formation which herein is regarded as being of Meramec and possibly also partly of Chester age; and the lower faunal zone, to that portion of the formation which herein is regarded as being of Osage (Keokuk) age. Rocks assigned to the upper faunal zone are present in all quad- rants of the Llano region. In the eastern part of the area, these rocks consist chiefly of olive-gray to yellowish—brown shales that are interbedded with a few thin argillaceous limestones; westward, the above-mentioned rocks merge into limestones, some of which are extremely crinoidal. Conodonts are numerous in most col— lections, but the faunal assemblage is small as only 10 genera and 18 species have been recognized in 65 collections. Some of these conodonts are present in the lower part of the Stanley shale of Oklahoma and Arkansas, as well as in the Caney shale of Oklahoma. Two new generic names, Gem'culatus and Roundya are proposed. P. V. Roundy’s conodonts from the Barnett formation have been studied and all of his type specimens have been refigured. Rocks assigned to the lower faunal zone of the Barnett forma- tion are known to be present only in the southwest quadrant of the Llano region. The fauna of this zone has been recognized in 20 collections but has not been described as it is poorly preserved. INTRODUCTION The Barnett formation of Mississippian age crops . out in the Llano region of Texas. It contains two conodont faunal zones: the upper faunal zone is re- stricted to that part of the formation which in this report is regarded as being definitely of Meramec and possibly also partly of Chester age; and the lower faunal zone, to that part of the formation which in this report is regarded as being of Osage (Keokuk) age. The conclusions of this paper are based on a study of specimens in 85 collections, most of which were made by the writer; of these collections, 65 are from the upper fauna] zone, and 20 are from the lower. Figure 4 indicates the localities, 0—1 to 0—17, at which these collections were made, and table 1 records the species present in each collection from the upper faunal zone. Conodonts collected by P. V. Roundy (1926)—— including those he described and figured—have been studied, and all of his type specimens have been re- figured. The known fauna of the upper zone is well preserved and consists of 10 genera and 18 species. That of the lower zone is poorly preserved, and, there— fore, is not described. Field work was done on four occasions. The first collections were made during the summer of 1938 while the writer was assisting Josiah Bridge with his studies of the lower Paleozoic rocks of the Llano region. As an examination of these collections indicated that cono- donts are abundant in the upper faunal zone of the Barnett formation, additional collections were made in August 1942, June and July 1945, and July 1950. During the 1945 field season, the writer spent 2 days with V. E. Barnes of the Texas Bureau of Economic Geology making collections from measured sections in Blanco and Burnet Counties; and 8 days with P. E. Cloud, Jr., of the United States Geological Survey making similar collections from sections located else— where in the Llano region. N . W'. Shupe photographed the fossils used to illustrate the paper. AGE OF THE BARNETT FORMATION The name, Barnett shale, was proposed by Moore and Plummer (1922, pp. 25, 26) for all of the limestone and shale beds between the Marble Falls limestone of Pennsylvanian age and the Ellenburger group of Early Ordovician age. They (Plummer and Moore, 1922, pp. 23, ‘24) regarded the Barnett as the exact equivalent of the “lower Bend shale”——the lowermost of the three units into which Dumble’s (1890, p. 65) Bend series was divided—and designated the exposure at Barnett Springs, “about 5 miles east of San Saba,” as the type locality. Girty (1926, p. 3), however, has stated that the Barnett is not the exact equivalent of the “lower Bend shale” but that it also contains beds originally assigned to the overlying Marble Falls limestone. For the most part, the base of the Barnett formation is easily recognized, though it is now known that, at many localities, a thin sequence of Mississippian and Devonian beds is present between that formation and the Ellenburger group. Opinions differ, however, as to where the base of the Barnett should be drawn in the southwest quadrant of the region, as beds occur there which some stratigraphers place in the Chappel limestone but which others place in the Barnett forma- tion. (See Weller, and others, 1948, pp. 143, 144, and 69 70 pl. 2, column 54; Cloud and Barnes, 1949, pp. 52—59; Plummer, 1950, pp. 26, 28.) Several opinions have been held concerning the age of the Barnett formation. One view, based on the work of Girty (1912, p. 8; 1919, pp. 71—81; 1926, pp. 3, 4; and Girty and Moore, 1919, pp. 418—420), held ‘ that the Barnett is a correlative of the Mississippian Caney shale; a formation that Girty (1926, p. 4) sug- gested might possibly be the equivalent of the entire interval from the base of the Moorefield formation to the top of the Fayetteville shale of Arkansas. Another view, based chiefly on the work of Moore, was that the Barnett is of early Pennsylvanian age. (See Moore, 1919, pp. 217—241; and Girty and Moore, 1919, pp. 418—420). Later (Plummer and Moore, 1922, pp. 23, 24) the age of these Carboniferous beds was considered to be uncertain and still more recently Plummer and Moore (1938, p. 104) have classified the Barnett as being definitely of Mississippian age. They also divided the formation into three units; the lowermost unit was correlated with the Moorefield shale (Moore- field formation and Ruddell shale of present usage) and the uppermost unit, with the Fayetteville shale. Miller and Youngquist (1948) have described some cephalopods from the Barnett formation. Most of their fossils were collected by Cloud, Barnes, and G. A. Cooper and came from localities 0—1, 0—10, 0—12, and 0—14 of this report. (See fig. 4.) Miller and Young- quist’s (1948, p. 651) views on the age and correlatives of the Barnett are given in the following statement: The collections now available for study indicate that there is only one [cephalopod] faunal zone in the Barnett, but we are not able to ascertain with certainty whether the fauna is upper Viséan or lower Namurian (or both) in age. Furthermore, the cephalopods do not indicate the correlative of the Barnett in the classical Mississippian section of the middle Mississippi Valley, for the beds there have yielded too few ammonoids. However, from a study of the cephalopods alone, we can conclude that the Barnett is of approximately the same age as the Caney of Oklahoma, the Moorefield, Ruddell, Batesville, and/or lower Fayetteville of Arkansas, the “Meramec” of Kentucky, the Helms of west Texas, the White Pine of Nevada and south- eastern California, and the goniatite—bearing portions of the Floyd of Georgia. A recent opinion on the age of the Barnett formation is that of Cloud and Barnes (1949, p. 59) who wrote: The lower limit of its age is virtually fixed as Keokuk, but the upper limit might be as high as Ste. Genevieve. The present authors [Cloud and Barnes] consider it extremely unlikely that any part of the Barnett formation is as young as Chester in age, ‘ and it is their opinion that it is actually entirely pre-St. Louis if not pre-Spergen. The greater number of species from the middle Mississippi Valley region that compare closely with Barnett species are either restricted to the Keokuk limestone or are known to occur in it. It is possible, therefore, that the Barnett formation and its correlatives, although provisionally referred to Keokuk plus Warsaw, are wholly of Keokuk age. A SHORTER CONTRIBUTION TO GENERAL GEOLOGY Plummer and Scott (1937) were of the opinion that the Barnett formation is upper Mississippian. Their work was based on a study of cephalopods. In his final publication, Plummer (1950, p. 43) correlated the Barnett with the Moorefield shale (Moorefield forma- tion and Ruddell shale of present usage) and placed both formations in the Chester. His opinion was that: The Barnett faunas correlate with the Moorefield of Arkansas and not with the Fayetteville or Pitkin. The Barnett faunas probably also are the time equivalent of the lower part (Okaw and older beds) of the Chester of Illinois and the Helms of west Texas * * * All four faunas [Barnett, Moorefield, lower Chester, and Helms] may represent more or less equivalent time space in the Upper Mississippian period. Clearly they all belong in the Chester series. It should be pointed out in this connection that Cloud and Barnes (1949) included in the lower part of the Barnett formation, beds that Plummer (1950) placed in the Chappel limestone as the White’s Crossing coquina member. Plummer considered these beds to be of Bur- lington age, Whereas Cloud and Barnes considered them to be of Keokuk age. Weller, and others (1948, p. 144) have summarized the prevailing opinions as follows: The Barnett shale is similar lithologically and faunally to the lower part of the Caney shale of Oklahoma. Generally, it has been correlated with the Chesterian * * * but its relations to the Ruddell shale of Arkansas seem to be much closer. Cloud believes that no strata younger than Warsaw occur in outcrop and correlates most of the formation with the Keokuk, but Plummer assigned at least part of it to a considerably higher position in the section * * * It is doubtful, however, that any strata of Chesterian age outcrop. CONODONT FAUNAL ZONES The United States Geological Survey at present recognizes the classification of the Barnett formation proposed by Cloud and Barnes (1949). According to these authors, the Barnett may range from Keokuk to Ste. Genevieve in age. But they were inclined to believe that the top is not so high as St. Louis, or pos- sibly Spergen, in age and even suggested that the entire formation could be of Keokuk age. These authors also regarded the Barnett of the Llano region as con- taining two interfingering lithologic facies; a predomi- nantly dark shaly facies in the eastern part of the area and a predominantly limestone facies in the western. The lowermost beds of the Barnett formation in the southwest quadrant of the Llano region have been found to contain conodonts distinct from those present in the immediately overlying beds of the formation. It is the writer’s opinion that these lower beds do not inter- finger with the predominantly shaly beds of the Barnett and, also, that the formation contains two distinct conodont faunal zones: (1) a lower zone of Osage CONODONTS OF THE BARNETT FORMATION OF TEXAS 71 (Keokuk) age which is confined to the basal part of the Barnett formation in the southwest quadrant of the Llano region, and which contains poorly preserved conodonts as well as the megafossil, Spirifer logam'; and (2) an upper zone of Meramec, and possibly partly of Chester, age which is present in the predominantly limestone sequence exposed in the western part of the Llano region—i. e. the beds above those containing the conodonts of the lower faunal zone—as well as in the predominantly shaly beds exposed in the eastern part of the area. Conodonts of this second zone are associ- ated with megafossils, some of which are also present in the Caney shale of Oklahoma, as well as in the inter- val from the base of the Moorefield formation to the top of the Fayetteville shale of Arkansas. (See Girty, 1919, pp. 71—78; 1926, pp.'3, 4; Plummer and Scott, 1937; and Miller and Youngquist, 1948.) LOWER CONODONT FAUNAL ZONE Exposures of this faunal zone are found in the south- west quadrant of the uplift and, for the most part, consist of light-gray, fine-, medium-, and coarse-grained, crinoidal limestones. The known conodont fauna con- sists of only a few small poorly preserved fossils and is not described. The genera Gnathodus, Hibbardella, Hindeodella, Ligonodina, Prioniodus, Roundya, and Subbryantodus are present, but Taphrognathus, which according to Branson and Mehl (1941d, p. 180) is characteristic of the Keokuk limestone of St. Louis County, Mo., has not been recognized. Some of the gnathodids resemble the Keokuk species, Gnathodus linguiformis Branson and Mehl. Rocks of this faunal zone include those that Plummer (1950, pp. 26, 28) placed in the White’s Crossing coquina member of the Chappel limestone. He considered such rocks to be of Burlington age. UPPER CONODONT FAUNAL ZONE Rocks of this zone crop out in all. quadrants of the Llano region. In the eastern part of the area, these rocks consist chiefly of olive-gray to yellowish-brown shales that are interbedded with a few thin argillaceous limestones, but in the western part of the area, they con- sist chiefly of light-gray to yellowish—gray limestones, some of which are extremely crinoidal. Conodonts are numerous and well-preserved in the upper faunal zone; however, the variety is limited, as only 10 genera and 18 species have been recognized in 65 collections. Gnathodus texanus, Gnathodus inomatus, Gnathodus bilineatus, Geniculetus claviger, Gawsgnathus cristata, Ligonodim roundyz', Lonchodim paraclarlci, and Roundya barnettana are the common species. All 18 species range throughout the entire faunal zone with the excep- tion of Gnathodus temnus and Priom’odus singularis; the former seems to be absent from the topmost beds of the zone, whereas the latter is apparently restricted to the topmost beds. The conodonts of the Barnett formation, that Roundy described in 1926 (pp. 8—17) are from the upper faunal zone. His work was based, for the most part, on an examination of a limited amount of material and, except for the holotype of Gnathodus teacanus, all of his figured specimens are fragments. It is the writer’s opinion that two of Roundy’s species, Polygnathus sp. A and Polyg- mthus tafi, were founded on reworked specimens. The first of these, Polygnathus sp. A, is based on a single fragmentary specimen which herein is identified as Palmatolepis glabra, a species whose normal strati- graphic range is considered by the writer to be restricted to a faunal zone in the Upper Devonian; and the other, Polygnathus tafi—also based upon a single specimen— belongs to a genus not known elsewhere to range above the Mississippian, Osage group. Roundy also included Lonchodus? lineatus (Pander) and Lomhodus simplex (Pander) in his Barnett fauna. For reasons given in the descriptive portion of the paper, it is believed that these two categories have no stratigraphic value. Below are listed the generic and specific names used by Roundy (1926) and the corresponding names used in this report: Names used by Roundy, 1926‘ Polygnathus? claviger Roundy. Priom‘odus healdi Roundy. Priom'odus sp. D, pl. 4, figs. 139., b (not fig. 12). {Palygnathus bilineata Roundy. Polygnathus texana Roundy. {Gnathodus tea-anus Roundy. Names used in this report. Gem'culatus claviger (Roundy). { Gnathodus bilineatus (Roundy). G’nathodus texanus var. bicus- pidus Roundy. Ctenognathus sp. A. Priom'odus sp. A. Priom‘odus sp. 0. Lonchodus? lineatus (Pander). Lonchodus simplex (Pander). Polygnathus sp. A. Gnathodus texanus Roundy. Hindeodella ensis Hass. Ligonodina roundyi Hass. _ Lonchodus lineatus (Pander). Lonchodus simplex (Pander). Palmatolepis glabra' Ulrich and Bassler. Polygnathus tafli Roundy. Priom'odus inclinatus Hass. Polygnathus tafii Roundy. Priom'odus sp. D, pl. 4, fig. 12, (not figs. 13 a, b). Priom'odus peracutus Hinde. Primiodus sp. B. Ctenognathus sp. B. Priom'odus ligo Hass. Priom'odus roundyi Hass. Subbryantodus roundyi Hass. Four small collections cited by Roundy (1926) have not been seen by the writer and are presumed to be lost. Roundy identified the following species in these lots: Collection 2610b. North side of road to Bend post office about 6 miles from San Saba * * * about 30 to 40 feet below the top of the Barnett shale. Priom'odus sp. (fragments) 72‘ Collection 2610c. Same locality as collection 2610b. :Ctenognathus sp. A ,Lonchodus simplex (Pander) ‘Polygnathus? claviger Roundy Priom'odus sp. (fragments) Collection 7011a (green). Four miles southwest of Chappel on road to Cherokee, San Saba County. From 25 to 30 feet above base of Barnett shale. Priom'odus sp. D? Collection 7687 (green). (green). Prioniodus sp. D COnodonts, similar to those present in the upper Probably the same locality as 7011a A SHORTER CONTRIBUTION TO GENERAL GEOLOGY faunal zone of‘ the Barnett formation, have been re— ported from the Caney shale of Oklahoma (Branson and Mehl, 1941a, pp. 167—178) and the lower part of the Stanley shale of Oklahoma and Arkansas (Hass, 1950). As a consequence of this similarity of conodont faunas, the writer (Hass, 1950) has suggested a partial correla- tion of the above-mentioned formations. The species on which this correlation is based are listed below, as some of the fossil names used in the present report differ from those previously used by the writer (Hass, 1950), as well as by Branson and Mehl (1941a) and Roundy (1926). Barnett formation, names used in Stanley shale, names used by present report Hass (1950) Caney shale, including names used by Branson and Mehl (1941) Barnett formation, names used by Roundy (1926) Bactrognathus claviger (Roundy) . Geniculatus claviger (Roundy). Euprioniodina? sp. (pl. 5, figs. 17, 18). Metalonchodina? sp. (pl. 5, fig. 15). Polygnathus? claviger Roundy. Priom'odus healdi Roundy. Prioniodus sp. D (pl. 4, figs. 13a, b; not fig. 12). .Cavusgnathus cf. 0. cm'stata Cavusgnathus cristata Branson and Branson and Mehl. Mehl. Cavusgnathus cristata Branson and Mehl. Not mentioned by Roundy. Gnathodus bilineatus (Roundy). ‘ Gnathodus bilineatus (Roundy). Gnathodus pustulosus Branson and Mehl. Polygnathus bilineata Roundy. Polygnathus texana Roundy. Gnathodus commutatus (Branson and Mehl). Gnathodus inornatus Hass. Spathognathodus commutatus Branson and Mehl. Not mentioned by Roundy. Gnathodus texanus Roundy. Gnathodus texanus Roundy. Gnathodus texanus Roundy. Gnathodus tezanus Gnathodus texanus cuspidus Roundy. Roundy. var. bi- Roundya barnettana Hass. Hibbardella sp. A. Present in Caney shale but not mentioned by Branson and Mehl. Not mentioned by Roundy. Hindeodella undata Branson and Mehl. Hindeodella undata Branson and 'Mehl. Hindeodella undata Branson and Mehl. Hindeodella sp. (pl. 5, fig. 9). Not mentioned by Roundy. Hindeodella ensis Hass. Hindeodella sp. A. Hindeodella sp. (pl. 5, fig. 1). Ctenognathus sp. A. ‘ Ligonod’ina roundyi Hass. Ligonodina sp. Genus present. Prioniodus sp. A. Prtom'odus sp. C. M etalonchodina sp. A. M etalonchodina sp. Genus present. Not mentioned by Roundy. Prioniodusinclinatus Hass. Priom'odus sp. A. Genus present. Priom'odus sp. D (pl. 4, fig. 12; not figs. 13a, b). ' Subbryalntodus roundyi Hass. Subbryantodus sp. Genus present. Ctenognathus sp. B. TABLE 1—D1‘stribution of conodant species in the upper faunal zone of the Barnett formation Locality C—l, Type locality of the Chappcl limestone mammniafi .502 To .flnwmhcv 22. m mX .35 ”com BE :IO 4.3mm M W .85 Hook BE SID .32 W W 35 semen 282 2'0 .wwmm m _ annm saw .8 38$me QIO .33 i‘ l. m mnwm cam Ho ammwfinom 0'0 .83 l! m enam dam .8 ammmfidow TO .mmca MI W 3mm dam “o pmmafidom mto .wmwm 1. my 3330 EPA wlo .33 um 395:0 5oz BIO .mmom m “$5.30 $94 TO .mnow m EQBEO $34 To swam m 2am 5m «0 £50m To #8 m spam 5% Ho gnaw N10 .omom 33 Sam Ho gnaw muO .mvma anmw dam «o Edam «IO .Nvmm $5 #030 umofl :10 .38 «En €20 amoq 2:0 .38 ”8,5 SHEA $>o 9585 9333 .210 .Emm 98 323 a w .8 33 963a a a. .58 eman 95.? t «m .omom awms 96nd“ n: «m .33 wmmn 952m 3 «m .88 8&2 959m 3 3 43m swan 95% a 3 .38 8.3 3on a E .omma awn 259a ”a w .83 swap 3on .E w a w 8 a m .33 3&9 025w .5 n fl 3 S .5 m. .3 w .nmsm ammo gone a S 3 t n .53 032 953a .5 n fl m 3 .5 H 9. m. .wmgm 2&9 ”Ken” .5 m 2 m 3 .E a S w .923 @mmn gona .5 m a N S .E a .cmSm .5 ¢ 33mm .323 .E w Emmm .wmoa Conodont species of upper faunal zone: avusgnathus cristata Branson and Mch1._ Geniculatus claviger (Roundy)........., Gnathodus bilineatus (Roundy). y ( Palmatolepis glabra Ulrich and Bassler_._......_. Priom‘odus inclinatus Hass, n. sp.. Prtom'odus ligo Hass, n. sp....__ Priom‘odus roundyi Hass, n. sp__ Prioniodus singularis Bass, n. sp. . Roundya barmttana Hess, n. sp... Subbryantodus roundyi Bass, 11. sp_.___.._......-..... Reworked species, described and figured by Roundy: Lanchodina paraclarki Bass, n. sp. Metalonchodina sp. A-_..-..____._ Gnathodus girtyi Kass, n. sp___. Gnathodus inomatus Hass, n. sp Gnathodus tetanus Rowdy", Hindeadella ensts Bass, n. sp..__.__._....__.. Hindeodella undata Branson and Mehl........ Ligonodina fragilis Bass, n. sp_._.______________ Ligonodina roundyi Bass, n. 51). Significant species: n $3 26% a 3 £2 m e . m M wmwfl 0>ona a.“ 8 .nde _ m B“ . H _. mm 8.8 25% a E dag m m mum . . _ v.n 82 393:5 £8 “ v a u m u u H mm. as 26%. a a. $2 H u u o _ . . L 82 38a a a £3 m m m 51m 3.3 383:2 is m m m 1.. n 2 .. . . Gym m 23 95% t we .28 m m w n nu _ _ _ me 82 38a a 8 .28 u n u o a _ _ _ LB 33 38a are .28 u h N h 38 33¢:an $8 N m m c . . _ m 82 25% a m: .wmmm N u h R . . _ . m 82 26$th .ng " h u n t _ . _ . m1 . . u u u " em as: 88.3.8 83 u u u " 1t _ _ _ _‘ Mm $8 9625;... 2% H n n u c _ _ ._ _ .w. 83 98% a s. .23 n V m m . _ . m 3.2 26% a am .33 n u H L _ . . $3 $2; a «m .23 H v m .m 32 $83st .88 x x w m m n _ .. n m 83 25% a...“ .88 xxx " ._ n h . _ . . mu 32 96% t E .33 xxx " n " Z 0 u h H mm was 95% a 3 3% xxx " u u _ w _ _ n _ h w. is Sonata. .28 xxxxxxx “xxxxxxx "xx “ h u t . _ . . _ — _ _ m 88 gassed... £8 xxxx mxx “xxxx "xx "x n u N n o . _ _ . _ _ _ _ _ _ u _ _ n H H L 33 8825. 5% m "x mxx "x u _ n u x " n n m. d w mu 3 m w .m H u d 0 .m n o L Lomhodus simplex (Pander).......................... ..._ ____ ___. .... W} Polygnathus ta/fi Roundy.___________._______.__._ Fragments without stratigraphic significance, described and figured by Roundy: 2313l3—53 (Face p. 72) CONODONTS‘ or THE BARNETT FORMATION OF TEXAS 73 MEASURED SECTIONS The faunal zonation of the Barnett is based on a study of the conodonts present in 85 collections (see fig. 4 and locality register pp. 76—77). Of these collec- tions, 63 are serials that come from the six localities described below. At these localities, the fauna of the lower zone was recognized in 20 collections and that of the upper zone in 43; information on the thickness of the Barnett formation was obtained from P. E. Cloud, Jr. Locality C—1, Type locality of the Chappel limestone: Cut on road from San Saba to Chappel near top of hill; 2.4 miles southeast of courthouse at San Saba, San Saba County. Feet Marble Falls limestone. Barnett formation: Upper conodont faunal zone: Shale, olive—gray where freshly exposed but yellowish-gray and yellowish- brown where weathered, fetid. A few thin lime- stone beds are present, mostly near top of forma- tion. Basal 6 inches locally contains glauconite_ _ 50 Collection no. Height above base 9331 ________ 42 feet 9026 ________ 34 feet 8649 ________ 24 feet 9006 ________ 24 feet 8651 ________ 19 feet 9007 ________ 19 feet 9330 ________ 19 feet 9329 ________ 8 feet 9030 ________ 8 feet to 8 feet 6 inches 2613h ........ 8 feet 5 inches to 10 feet 5 inches 2618- A _ n--- 5 feet to 10 feet 2613g- _ _ _‘_ _ _ 5 feet 1 inch to 8 feet 5 inches 2613e _______ 2 feet 9 inches to 5 feet 1 inch 2613d _______ 9 inches to 2 feet 9 inches 2613c _______ 0 to 9 inches 9028 ________ 0 to 6 inches Chappel limestone. Ives breccia. Honeycut formation. Locality C—12, Zesch Ranch section: About 5,000 feet N. 60° W. of point at which Honey Creek crosses the road from Mason to White’s Crossing over the Llano River in Mason County. Marble Falls limestone. Feet Barnett formation: Upper conodont fauna] zone: Limestone, yellowish- gray, medium— to coarse-grained, argillaceous, fetid; partly covered _________________________________ 60 Height above Collection no. base, in feet 9309 __________________________________ 84 9322 __________________________________ 75 9321 __________________________________ 70 9320 __________________________________ 65 9319 __________________________________ 60 931 8 __________________________________ 53 9317 __________________________________ 42 231313_53_._2 Barnett formation—Continued Lower conodont faunal zone: Limestone, predomi- nantly very nearly white, medium- to coarse—grained, crinoidal. Some beds are yellowish gray and pinkish gray; some are fine—grained. (Two un- numbered collections were made from the rocks of this zone; one collection came from the basal foot and the other from the top foot) _______________ 30 Feet Total ______________________________________ 90 Chappel limestone. Gorman formation. Locality C~1 3, White’s Crossing over the Llano River: Approxi- mately 8.3 miles (airline) southwest of the courthouse at Mason, Mason County. Barnett formation: Feet I LOWer conodont faunal zone: Limestone, very nearly white to light-gray, fine-grained to sublithographic ______________ 2 Limesand, very light gray to yellowish-gray where freshly exposed but moderate reddish- orange and moderate reddish-brown where weathered; very coarse grained except for a few sublithographic beds ___________________ 11 Total __________________________________ 1 3 Chappel limestone. Collections were made on two occasions. The first collection (9312), made by the writer in July 1945, came from fragments of a slab of rock from which P. E. Cloud obtained some megafossils, including Spirifer logani. The recognizable conodonts of this collection belong to the upper conodont fauna] zone. Late in 1945, at the request of the writer, Cloud and Barnes made seven serial collections from the lower 13 feet of the Barnett at White’s Crossing; six of these collections were examined, and all were found to contain the conodonts of the lower faunal zone. It is a writer’s opinion that the specimens of collection 9312 are con- taminants, and that their association with Spirifer logani is the result of a stratigraphic leak. Support for this View is found in the fact that a collection of con- odonts from the basal beds of the Stribling formation at its type locality near Johnson City, Blanco County, Tex., contains conodonts of the upper faunal zone of the Barnett formation. These conodonts Were found filling a crack that is only one-quarter of an inch Wide. The presence of Mississippian conodonts in the Stribling (Early or Middle Devonian age) formatidn must be explained as being the result of a stratigraphic leak; and, by analogy, the presence of collection 9312 in rocks which subsequently have yielded only the species of the lower faunal zone can be interpreted in a like manner. 74: A SHORTER CONTRIBUTION TO GENERAL GEOLOGY Locality 0-14, Barton Ranch section 1: About 8,200 feet 8'. 14° W. of the southwest bank of the Llano River at White’s Crossing, Mason County. Feet Marble Falls limestone. Barnett formation: Upper conodont faunal zone: Covered, probably Barnett formation _________ 10 Limestone, nearly white where freshly exposed but gray where weathered; coarse-grained ex- cept for a few, fine-grained and sublithographic beds; partly covered ______________________ 115 Height above Collection no. base, in feet 9339 ______________________________ 135 9338 ______________________________ 118 9337 ______________________________ 108 9336 ______________________________ 80 9335 ______________________________ 63 9334 _______________________________ 50 9332 ______________________________ 40 9333 ______________________________ 39 9313 ______________________________ 34 Lower conodont faunal z'one: Limestone, similar to that of the upper conodont faunal zone. (Four un— numbered collections were made from the rocks of this zone. They came from the basal 2 inches; 18 inches above the base; 10 to 11 feet above the base; and 18 feet above the base) _______________ 20 Total ______________________________________ 145 Chappel limestone. Gorman formation. Locality C—15, Barton Ranch section 2: About 2,500 feet N. 88° W. of the southwest bank of the Llano River at W7hite’s Crossing, Mason County. Feet Marble Falls limestone. Barnett formation: Upper conodont faunal zone: Covered, probably shale _____________________ 15 Limestone, principally white, coarse-grained, crinoidal _________________________________ 5O Limestone, dark—gray, medium-grained, fetid__ 5 Covered, probably shale _____________________ 15 Limestone, brownish-gray, granular, a coquina of megafossils, in part splits along greenish shale partings ____________________________ 5 Height above Collection no. base, in feet 9311 __________________________________ 125 9316 __________________________________ 102 9315 __________________________________ 90 9310 __________________________________ 55 _ Barnett formation——Continued Fm Lower conodont faunal zone: Limestone, light-gray to white, coarse-grained, crinoidal; interbedded with fine—grained to sublithographic limestone. Speckled, granular, crinoidal chert concretions near middle of this interval. (Two unnumbered collections were made from the rocks of this lower conodont faunal zone. One collection was ob- . tained 5 feet above the base and the other, 15 feet above the base.) ______________________________ 50 Total______;_y_ ________ : ____________________ 140 Chappel limestone. ‘ Gorman formation. Locality C—16', Barnett Trench section: About 2,100 feet.due west of point at which Honey Creek intersects the road from Mason to White’s Crossing over the Llano River in Mason County. Feet Marble Falls limestone. Barnett formation: Upper conodont faunal zone: Mostly covered. Lime- stone, yellowish—gray; fine-, medium-, and coarse— grained. Some very light gray limesand near the top of the section. Approximately 20 feet of the interval consists of exposed ledges of rock, remain- ing 88 feet is covered by caliche and may represent shaly beds ___________________________________ 108 Height above Collection no. base, in feet 9328 __________________________________ 115 9327 __________________________________ 90 9326 __________________________________ 72 9325 __________________________________ 67 9324 __________________________________ 42 9323 _________ 1 ________________________ 24 Lower conodont faunal zone: , Limestone, very nearly white to very light gray, fine-grained ______________________________ 1. 5 Limestone, very nearly white to very light gray, coarse-grained ____________________________ 9. 5 Limestone, very nearly white, very fine grained to sublithographic ________________________ 1. 0 Limestone, very nearly white to very light gray, fine-grained ______________________________ 10. 0 Total __________________________________ 130. 0 Six collections, all unnumbered, came from the follow- ing intervals: Height above base 16 feet to 17 feet. 12 feet to 15 feet. 10 feet to 10 feet 6 inches. 10 inches to 16 inches. 5 inches to 10 inches. 4 inches to 5 inches. Chappel limestone. Gorman formation. CONODONTS OF THE BARNETT FORMATION OF TEXAS 75 99’30' 99‘00I 98"30' I 3F ~Marble Falls /L\alre Tray/s A203 ‘71, 337 \Spicewood ' \Jz’i Cyprus Min / / C 0 C-Ilo I \ / \ - /son City I J I 5 o lo Miles L..L_4L+L_1__—J_——._J ”m4 ! | 1 I 1 / 99‘ 30' 99' 00' 98‘ 30' FIGURE 4.—Map showing localities at which oonodonts of the Barnett formation were wuected. 76 This section is a composite one. A SHORTER CONTRIBUTION TO GENERAL GEOLOGY Beds of the lower faunal zone of the Barnett formation were measured and sampled at an exposure located approximately 500 feet northeast of the one at which beds of the upper zone were measured and sampled. LOCALITY REGISTER Listed below are individual localities from which conodonts were collected: Conodont localities, upper faunal zone, Barnett formation Number on fig. 4 Collec- tion number Collector, year of collection, description of locality 2609 2610b 26100 26130 261 3d 26139 2613g 261311 261 8 2688 7011a (green) 7016 (green) 7687 (green) 8649 8650 8851 8652 9007 9020 9021 9025 9026 P. V. Roundy, 1919. South side of road to Bend post office, about 614 miles from San Saba, San Saba County, Tex. P. V. Roundy, 1919. Along the Bend-San Saba road, at north end of a small hill. About 5 miles east and 1y; miles south of the courthouse at San Saba, tsabl Slaba County, Tex. Collection not listed on a e . P. V. Roundy, 1919. Same locality as 2610b. Col- lection not listed on table 1. P. V. Roundy, 1919 . At type locality of the Chappel limestone. Cut on road from San Saba to Chappel, well up on side of hill; 2.4 miles southeast of court- house at San Saba, San Saba County, Tex. From basal 9 inches of formation. P. V. Roundy, 1919. Same locality as 26130. From a 2-foot interval, 9 inches to 2 feet 9 inches above the base or the formation. P. V. Roundy, 1919. Same locality as 26130. From a 2-foot 4-inch interval, 2 feet 9 inches to 5 feet 1 inch above the base of the formation. P. V. Roundy, 1919. Same locality as 26130. From a 3-foot 4-lnch interval, 5 feet 1 inch to 8 feet 5 inches above the base of the formation. P. V. Roundy, 1919. Same locality as 2613c. From a 2-foot interval, 8 feet 5 inches to 10 feet 5 inches above the base of the formation. P. V. Roundy, 1919. Same general locality as 2613c but about 1,000 feet to east. From a 5-foot interval, 5 to 10 feet above the base of the formation. K. C. Heald, 1919. Along road 4.9 miles east and 0.9 mile south of the courthouse at San Saba, San Saba County, Tex. E. O. Ulrich and J. W. Beede, date of collection not known. About 4 miles southwest of Chappel on the road to Cherokee, San Saba County, Tex. About 25 to 30 feet above the base of the formation. Collection not listed on table 1. E. O. Ulrich and J. A. Taff, 1903(?). On road from Sulphur Creek to Llano, 5% miles west of Lam- pasas, northern Burnet County, Tex. G. H. Girty, 1910. About 4 miles southwest of Chappel on the road to Cherokee, on small hill just east of creek that flows into Cherokee Creek and about 1 mile southeast of point at which road crosses the creek. Probably same locality as collection 7011a (green). Not listed on table 1. . . Hass 1942. Same locality as 26130. From goodside ditch, about 24 feet above base of forma- ion. W. H. Hass, 1938. Southeast of San Saba. Roadside ditch along the San Saba-Bend road. About 61.4 miles from San Saba, San Saba County, Tex. W. H. .Hass 1938. Same locality as 26130. From roadsrde ditch, about 19 feet above the base of the formation. W. H. Hass, 1938. Same locality as 9059. From between two conspicuous layers of concretions. W. H. Bass, 1942. Same locality as 2613c. From roadside ditch, about 24 feet above the base of the formation. , W. H. Hass, 1942. Same locality as 2613c. From roadside ditch, about 19 feet above the base of the formation. W. H. Hass, 1942. South of San Saba. Roadcut on State Route 16, at top of hill, about 4.6 miles (by road) south of courthouse at San Saba, San Saba County, Tex. From a 6inch interval, 6 to 12 inches above the base of the formation. W. H. Hass, 1942. Same locality as 9020. From a 3-mch-thick indurated bed, top of which is 4 feet above the base of the formation. W. _H. Hass, 1942. Southeast of San Saba. In road- snde ditch, at sharp turn on the San Saba-Bend road, about one mile from the junction with United States Highway 190. About 4.4 miles from the courthouse at San Saba, San Saba County, Tex. W. H. Hass, 1942. Same locality as 26130. From roadcut, about 34 feet above base of the formation. Conodont localities, upper faunal zone, Barnett formation—Con. Number on fig. 4 Collec- tion number Collector, year of collection, description of locality C—7 ............... C—l _______________ C—15_ , _, __________ C—15 ______________ C—13 ______________ C-14 ______________ C—15 ______________ C—15 ______________ C—12 ______________ C-12 ______________ C-l2. _ _, .......... C—12 .............. C—12 .............. C—12 ............... C—16. _ _, .......... C—16 ______________ C—16 ______________ C—16 ______________ C—16 ______________ C—16 ______________ C—l _______________ C—l4 ______________ C—14 ______________ C—14 .............. C—14 .............. C—14 ______________ 9027 9028 9029 9030 9059 9309 9310 9311 9312 9313 9315 931 6 931 7 9318 931 9 9320 9321 9322 9323 9324 9325 9326 9327 9328 9329 9330 9331 9332 9333 9334 9335 9336 W. H. Hess, 1942. Same locality as 9059. About 5 to 6 feet stratigraphically below collection 9059. W. H. Hass, 1942. Same locality as 2613c. From the basal 6 inches of the formation. W. H. Hass, 1942. Near Chappel. About 4.1 miles from the schoolhouse at Chappel on the Cherokee- Chappel road, San Saba County, Tex. From borrow pit on north side of road. H. Hass, 1942. Same locality as 2613c. From a 6-inch interval, immediately beneath a 6-inch lime- stone bed, 8 feet to 8 feet 6 inches above the base of the formation. W. H. Hass, 1942. Near Chappel. Cut on the San Saba-Channel road about 1.2 miles from the school- house at Chappel, San Saba County, Tex. Collec- tion from zone between two conspicuous layers of concretions. W. H. Hass, 1945. Zesch Ranch section. About 5,000 feet N. 60° W. of point at which Hone Creek crosses the road from Mason to White’s rossing over the Llano River. Along the southeast side of a prominent hill at the head of a draw that enters Honey Creek from the west side, about 0.6 mile upstream from the above-mentioned road crossing on Honey Creek, Mason County, Tex. About 84 feet above the base of the formation. W. H. Haas, 1945. Barton Ranch section 2. About 2,500 feet N. 88° W. of the southwest bank of the Llano River at White’s Crossing. At the axis of a rominent northeast draining draw, Mason County, ex. About 55 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9310. About 125 feet above the base of the formation. W. H. Hess and P. E. Cloud, 1945. White’s Crossing. About 8.3 miles (airline) southwest of the court- house at Mason, Mason County, Tex., and immedi- ately north of White’s Crossing on east bank of the Llano River. W. H. Hess, 1945. Barton Ranch section 1. About 3,200 feet S. 14° W. of the southwest bank of the Llano River at White’s Crossing. Near southern end of the northwest slope of an elongate hill to the south of Bee Branch, Mason County, Tex. About 34 feet above the base of the formation. W. H. Hess, 1945. Same locality as 9310. About 90 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9310. About 102 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9309. About 42 feet above the base of the formation. W. H. Hess, 1945. Same locality as 9309. About 53 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9309. About 60 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9309. About 65 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9309. About 70 feet above the base of the formation. . H. Hass, 1945. Same locality as 9309. About 75 feet above the base of the formation. W. H. Hess, 1945. Barnett Trench section. About 2,100 feet due west of point at which Hone Creek crosses the road from Mason to White’s rossing over the Llano River. The locality is about 1,400 feet up from the mouth of an east-northeast drain- ing draw that enters Honey Creek from the south- west about 1,000 feet upstream from the above- mentioned road crossing, Mason County, Tex. About 24 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9323. About 42 feet above the base of the formation. W. H. Bass, 1945. Same locality as 9323. About 67 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9323. About 72 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9323. About 90 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9323. About 115 feet above the base of the formation. P. E. Cloud and V. E. Barnes, 1945. Same locality as 2613c. About 8 feet above the base of the forma- tlon. P. E. Cloud and V. E. Barnes, 1945. Same locality as 2613c. From roadside ditch, about 19 feet above the base of the formation. P. E. Cloud and V. E. Barnes, 1945. Same locality as 2613c. From a limestone bed located about 8 feet below the top of the formation. W. H. Hass, 1945. Same locality as 9313. About 40 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9313. About 39 feet above the base of the formation. W. H. Hess, 1945. Same locality as 9313. About 50 feet above the base of the formation. Collection not listed on table 1. W. H. Hess, 1945. Same locality as 9313. About 63 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9313. About 80 feet above the base of the formation. CONODONTS OF THE BARNETT FORMATION OF TEXAS Conodont localities, upper founol zone, Barnett formation—Con. Collec- tion number Number on fig. 4 Collector, year of collection, description of locality 0—14 ______ , ........ C—14 ______________ C—14 ______________ ‘ C—17 ______________ W. H. Hass, 1945. Same locality as 9313. About 108 feet above the base of the formation. W. H. Hess, 1945. Same locality as 9313. About 118 feet above the base of the formation. W. H. Hass, 1945. Same locality as 9313. About 135 feet above the base of the formation. P. E. Cloud and V. E. Barnes, 1945. Lost Creek area. About 1.7 miles N. 60° E. of the mouth of Lost Creek which empties into the San Saba River just east of the slab-crossing of the San Saba River on the Voca to Long Valley road and about 600 feet southwest of the mouth of Jim Davis Hollow, southeastern McCulloch County, Tex. From highest exposed ledge of limestone. > P, E. Cloud and V. E. Barnes, 1945. Same locality as 9340. From lowest exposed ledge of limestone. P. E. Cloud and V. E. Barnes, 1945. South of San Saba. Cut on State Route 16, 5 miles (by road) south of the courthouse at San Saba; the locality is north of Elm Branch and south of a bridge over Simpson Creek, San Saba County, Tex. From a fossiliferous limestone, several inches thick, whose top surface is 9 inches below the top of the forma- mm. P. E. Cloud and V. E. Barnes, 1945. Same locality as 9342. From topmost 9 inches of the formation, immediately above collection 9342 and below a 6-inch bed of glauconitic rock. P. E. Cloud and V. E. Barnes, 1945. Moore Hollow area of the Riley Mountains. About 1,900 feet due west of a point on the Llano-Click road, approxi- mately 1.9 miles south of the crossing on Honey Creek Llano County, Tex. . V. E. harnes, 1945. Elm Pool area. About 5.3 miles south-southwest of Cypress Mill, ap roxi- mately 2 miles southwest of the Cage Ranch ead- quarters, 4,000 feet north of the mouth of Miller Creek, Blanco County, Tex. From the basal 6 inches of the formation. V. E. Barnes, 1945. Same locality as 9345. From a 6-inch interval, 3 feet to 3 feet 6 inches above the base of the formation. 9337 9338 9339 9340 9342 9343 9344 0—11 ______________ 9345 0-11 .............. 9346 , SYSTEMATIC DESCRIPTIONS In the descriptions that follow, the blade and carina of a platelike conodont together comprise the axis of the fossil. The blade is defined as the portion of the axis which is anterior to the apex of the pulp cavity and the carina as the portion which is posterior to the same structure. The specimens described and illustrated in this paper have been deposited in the U. S. National Museum. Genus CAVUSGNATKUS Harris and Hollingsworth, 1933 1933. Covusgnothus Harris and Hollingsworth, Am. Jour. Sci., 5th ser., vol. 25, pp. 200, 201. , 1933. C’ovusgnathus Harris and Hollingsworth. Gunnell, Jour. Paleontology, vol. 7, p. 286. 1941. Covusgnathus Harris and Hollingsworth. Ellison, Jour. Paleontology, vol. 15, pp. 125, 126. 1944. Covusgnothus Harris and Hollingsworth. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 245. Genotype, by original designation and by monotypy, Cavus— gnothus alto Harris and Hollingsworth, 1933. Cavusgnathus cristata Branson and Mehl Plate 14, figures 12—14 1941. Covusgnathus sp. Hass, Jour. Paleontology, vol. 15, pl. 14, fig. 6. ' 1941. Covusgnathus crisioto Branson and Mehl, Denison Univ., 77 Sci. Lab., Bull, vol. 35, p. 177, pl. 5, figs. 26—31. (Date of imprint, 1940.) Hypotypes: U.S.N.M. 115087, 115088, 115089. Oral view-An elongate unit with perpendicular sides, narrow platforms, a median trough, and a blade that is. continuous with the outer platform. Carina may be evident at pointed posterior end of plate. Blade shorter than portion of fossil which is posterior to the pulp cavity; it is high, abruptly set off from oral surface of outer platform, and extends a short distance to anterior of inner platform. Denticles of blade large, even on inner side, expanded on outer side; each is fused nearly to its pointed sharp-edged tip. Surface of platforms ridged transversely; these platforms pitch steeply and together form a smooth, narrow, faintly sinuous trough that increases in depth toward the anterior end of fossil, where it is open. . “ Loterol view—With reference to the aboral side of the plate, the blade is angled downward slightly. Summit line of inner and outer platforms minutely dentate, level or slightly arched; that of blade dentate and cristiform. Anterior end of inner platform truncate. Aborol view—Blade sharp-edged to a point near its posterior end, where it is split and merges into the cup (i. e. expanded pulp cavity). Pulp cavity lanceolate in outline; its sides pitch toward grooved midline of plate. Apex of pulp cavity located near anterior end of con— cavity. Oovusgnothus cristoto may be a synonym of Cocos- gnothus alto Harris and Hollingsworth (1933). The writer’s specimens have been compared with the holo- type of C'. olto, and although no important differences were noted, the author is reluctant to make a positive identification, as Harris and Hollingsworth’s type speci- men is quite fragmentary. \ Distribution: Barnett formation; upper faunal zone. Genus GENICULATUS Hass, In. gen. Genotype, here designated, Polygnothus? cloviger Roundy, 1926 A geniculate, asymmetric, massive, barlike unit which tapers from the vertex toward the anterior and posterior extremities. Unit slightly arched, denticu- lated. Main cusp at vertex. Aboral side grooved along midline; pulp cavity located beneath main cusp. An immature specimen consists of a distinct posterior bar, a main cusp, and a distinct anterior bar which is joined to inner side of the main cusp. A large genicu- late unit was built about this framework through'the accretion of numerous lamellac. Geniculatus claviger (Roundy) Plate 15, figures 10—19 1926. Polygnathus? cloviger Roundy, U. S. Geol. Survey Prof. Paper 146, p. 14, pl. 4, figs. la—c; 2a, b. 778 1926. Priom'odus healdi Roundy, U. S. Geol. Survey Prof. Paper 146, p. 10, pl. 4, figs. 5a, b. Priom'odus sp. D Roundy [part], U. S. Geol. Survey Prof. Paper 146, p. 11, pl. 4, figs. 13a, b [not fig. 12=Prieni- odus inclinatus]. ‘ Euprioniodina? sp. Branson and Mehl, Denison Univ., Sci. Lab., Bull., v01. 35, p. 171, pl. 5, figs. 17, 18. (Date ‘of imprint, 1940.) Metalonchodina? sp. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 172, pl. 5, fig. 15. (Date of imprint, 1940.) Bactrognathus claviger (Roundy). Jour. Paleontology, vol. 15, p. 99. Bactrognathus inornata Branson and Mehl, Jour. Paleon- tology, vol. 15, p. 100, pl. 19, figs. 14, 15. Holotype: By original designation, the specimen shown by Roundy, 1926, as figures la—c on plate 4, U.S.N.M. 115066 [=U.S.G.S. Carb. cat. 4015a]. Paratype: The specimen shown by Roundy, 1926, as figures 2a, b on plate 4, U.S.N.M. 115068 [=U.S.G.S. Carb. cat. 4016a]. Hypotypes: The holotype of Priom'odus healdi Roundy, U.S.N.M. 115073 [=U.S.G.S. Carb. cat. 4034a]; the specimen of Priom'odus sp. D figured by Roundy, 1926, as figures 13a, b on plate 4, U.S.N.M. 115067 [=U.S.G.S. Carb. cat. 4036a]; also U.S.N.M. 115069, 115070, 115071, 115072, 115074, 115075. Type locality: C—6, road to Bend post office, about 6% miles from San Saba, San Saba County, T ex.; collection 2609. 1926. 1941. 1941. 1941. Branson and Mehl, 1941. Oral view—A young specimen consists of a denticu- lated posterior bar that supports the main cusp, and a shorter, denticulated anterior bar that is joined to the inner side of the main cusp. During ontogeny, through the accretion of lamellae, the posterior and anterior bars gradually evolved into a massive, geniculate, bar- like unit. This unit is asymmetric, broadest at the vertex, and tapered toward the extremities; its denticles are slightly curved and are generally located nearer the outer than the inner side of the fossil. Other characteristics are more variable. Denticles may range from short to long, straight to curved, discrete to appressed, and peglike to toothlike. The main cusp also varies in size and shape. Sharp edges generally divide the cusp into a smaller, even, inner side and a larger, expanded outer side. In transverse section, the anterior and posterior bars of a young specimen are higher than wide and their convex sides are broadest at or below midheight ; the bars of a more mature specimen are completely merged to form a geniculate unit which, at the vertex, is several times wider than high. “Lateral view—Aboral side of unit slightly arched. Summit line of unit dentate, incised, and irregular. Aboral view—Aboral side of unit tends to be set ofl’ from remainder of fossil by a continuous ridge; area thus enclosed may be excavated. Pulp cavity tends to be large, and triangular to elliptical in outline. Geniculatus claviger is a common species in the upper faunal zone of the Barnett formation. Most specimens are fragments but a sufiicient number has been examined to indicate that during its ontogeny a member A SHORTER CONTRIBUTION TO GENERAL GEOLOGY of this species changed from a fragile barlike conodont into a massive geniculate one. Branson and Mehl (19410, p. 99) would place Polygnathus? clam'ger Roundy in the genus Bactrognatkus but the writer of this report believes that no such relationship exists. This opinion is held because the genotype of Bactrognathus, B. hamata, appears to have been derived from a bladelike conodont, similar to Spathognathodus, whereas Gem'cu— latus claviger seems to have evolved out of a barlike conodont, similar to Lonchodz'na. Bactrognathus inomata Branson and Mehl is believed to be a synonym of Geniculatus claviger (Roundy). Branson and Mehl’s species (19410, p. 97) comes from the “Sycamore of Pontotoc County, Oklahoma,” a formation which some geologists place in the lower part of the Caney shale and which Branson and Mehl do not attempt to correlate with the type locality of the Sycamore limestone. The presence of G. claviger would suggest that the age of the “Sycamore of Pontotoc County” is approximately the same as that of the Caney shale. It should be pointed out, however, that Branson and Mehl (19410, pp. 99, 101—103) have also described Bactrognathus angularis, B. distorta, B. excavata, D0171- ognathus (labia, and Staurognathus cruczjormis from the same beds. It is the writer’s opinion that an association of the last-named species with Gem'culatus claviger is indicative of a mixed fauna. This interpretation is based on the fact that in the Llano region, Gem'culatus has been found only in the upper faunal zone of the Barnett formation (Meramec and possibly in part Chester) Whereas Dolz'ognathus, Staurognathus, and Bactrognathus have been found only in the topmost beds of the Chappel limestone of Chouteau age. Distribution: Barnett formation; upper faunal zone. Genus GNATI-IODUS Pander, 1856 1856. Gnathodus Pander, Monographie der fossilen Fische des silurischen Systems der russisch—baltischen Gouverne- ments, pp. 33, 34. Gnathodus Pander. Bryant, Buffalo Soc. Nat. Sci. Bull., v01. 13, no. 2, p. 22. Gnathodus Pander. Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, p. 54. Gnathodus Pander. Roundy, U. S. Geol. Survey Prof. Paper 146, p. 12. Gnathodus Pander. Branson and Mehl, Missouri Univ. Studies, vol. 13, no. 4, pp. 136, 144. Dryphenotas Cooper, J our. Paleontology, vol. 13, p. 386. Gnathodus Pander. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 245. Genotype, by monotypy, Gnathodus mosquensz‘s Pander, 1856. 1921. 1926. 1926. 1938. 1939. 1944. Gnathodus bilineatus (Roundy) Plate 14, figures 25—29 1926. Polygnathus bilineata Roundy, U. S. Geol. Survey Prof. Paper 146, p. 13, pl. 3, figs. 10a-c. CONODONTS OF THE BARNETT FORMATION OF TEXAS Polygnathus texana Roundy, U. S. Geol. Survey Prof. Paper 146, p. 14, pl. 3, figs. 13a, b. Gnathodus bilineatus Roundy [sic]. Cooper, Jour. Pale- ontology, vol. 13, p. 388 [not pl. 42, figs. 59, 60]. 1926. 1939. 1939. Gnathodus texanus (Roundy). Cooper, Jour. Paleon- tology, vol. 13, p. 388 [not pl. 41, figs. 26, 27]. 1941. Gnathodus pustulosus Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 172, pl. 5, figs. 32—39. (Date of imprint, 1940.) Holotype: By original designation, the specimen shown by Roundy, 1926, as figures 10a-c on plate 3, U.S.N.M. 115101 [=U. S. G. S. Carb. cat. 4021a]. Hypotypes: The holotype of Polygnathus texana Roundy U.S.N.M. 115103 [=U. S. G. S. Carb. cat. 4013a]; also, U.S. N.M. 115100, 115102, 115104. Type locality: 0—6, road to Bend post office, about 6% miles from San Saba, San Saba County, Tex.; collection 2609. Oral view.——Axis straight to slightly angled inward at junction of blade and carina. Carina broader than oral portion of blade; it rises higher above the cup of a young specimen than of a mature one. Generally, the carina is curved downward at the posterior end of the cup, though on some specimens it is high and ridgelike throughout its entire length. Denticles of carina fused nearly to their tips; they are largest over posterior two-thirds of cup, where, commonly, the tips are chevron-shaped or even modified into transverse ridges through their fusion with adjacent nodes. The cup of a young specimen is elongated antero-posteriorly; that of a mature one is more transverse. All cups are asymmetrical, widest anteriorly, and pointed poste— riorly. Outer side of cup of a young specimen is narrow, thin, and arched; that of a mature one is expanded laterally in its anterior two-thirds. The expansion thus formed is semicircular to subrectangular in out- line. Oral surface of this expansion may be slightly concave or slightly convex, and posteriorly, adjacent to the carina, it may be marked by a smooth narrow depression. This expansion bears nodes, or nodes and ridges, that differ from each other in size and shape; generally, they are arranged in concentric rows about the apex of the pulp cavity. Inner side of cup is higher, slightly longer, and much narrower than outer side. The anterior third of the inner side rises as high as the adjacent portions of the blade and carina and Original name, Roundy, 1926 Gnathodus texanus Roundy ___________________ Gnathodus texanus var. bicuspidus Roundy _____ Polygnathus tcxana Roundy __________________ Polygnathus bilineata Roundy ________________ Although Cooper (1939, pp. 388, 419) has stated that Gnathodus bilineatus (Roundy) [=Polygnathus bilineata Roundy, 1926] and Gnathodus texanus (Roundy) [=Polygnathus texana Roundy, 1926] are present in the lower Mississippian of Oklahoma, his citations are not included in the synonymy of G'. bilineatus (Roundy) Changes by Cooper, 193.9 Spathodus tetanus (Roundy) _________ } Gnathodus texanus (Roundy) _________ Gnathodus bilineatus (Roundy) _______ 79 with them forms a narrow trough; the middle third tends to be wider and lower than the anterior third; the posterior third is quite narrow and merges into the carina. Anterior portion of inner side ornamented with transverse ridges; posterior portion ornamented with ridges and nodes. Blade as much as 1% times longer than carina, massive adjacent to pulp cavity, thickest near aboral side. Denticles of blade gradually in- crease in size anteriorly: each denticle is thickest along its midline and has a sharp-edged tip. Lateral view—With reference to the aboral side, fossil increases in height anteriorly. Summit line of carina irregular; that of blade dentate. Profile of aboral side of cup is slightly concave. Aboral view—Blade split toward its posterior end Where it merges into sides of expanded pulp cavity (i. e. cup). Pulp cavity grooved along midline, deeply concave in young specimens and broadly so in mature ones. Apex of pulp cavity located near anterior end of the concavity. The following species, described by Roundy in 1926, are gnathodids: Gnathodus texanus, Grmthodus texanus var. bicuspidus, Polygnathus texana, and Polygnathus biling- ata. Subsequent work has resulted in some of. the above species being misnamed. Cooper (1939, p. 416), who evidently accepted Branson and Mehl’s (1938, p. 136) suggestion that G’nathodus temnus and szthodus texanus var. bicuspidus are probably “peculiarly modi- fied spathodids,” placed Gnathodus tezanus Roundy in the genus Spathodus Branson and Mehl, 1933 (=Nodognath'us Cooper, 1939; and Spathognathodus Branson and Mehl, 1941). Cooper (1939, p. 388) also placed Polygnathus texana Roundy and P. bilineata Roundy in the genus Gnathodus, but, as indicated above, so far as Polygnathus texana is concerned, Roundy had previously used the name G'nathodus temnus for another species of Gnathodus. In the present paper Roundy’s Polygnathus bilineata is considered to be conspecific with his Polygnathus texana, and, as the specific name bilineata is available, the correct name of this species is regarded as being G’nathodus bilineatus (Roundy). The nomenclatorial changes that Roundy’s species have undergone are listed below: Names used in present paper Gnathodus lemmas Roundy. }Gnathodus bilineatus (Roundy). because Roundy’s species possesses many character— istics not recorded by Cooper. Polygnathus bilineata Roundy is based on a single fragmentary specimen which lacks the posterior end of the cup as well as the , anterior end of the blade; Polygnathus texana Roundy is also based on a single fragmentary specimen which 80 lacks most of the blade and has a fracture that paral- lels the carina on the outer side of the cup. Specimens of Gnathodas billneatus (Roundy) are very common in the upper faunal zone of the Barnett formation where they are found associated with specimens of Gnathodus teranus. These two species are easily identified through the ornamentation of the cup. Distribution: Barnett formation; upper faunal zone. Gnathodus girtyi Bass, n. sp. Plate 14, figures 22—24 Holotype: U.S.N.M. 115097. Paratypes: U.S.N.M. 115098, 115099. Type locality: C—15, about 2,500 feet N. 88° W. of southwest bank of Llano River at White’s Crossing, Mason County, Tex. ; collection 9310. Oral views—Axis straight to slightly curved inward. Denticles of anterior portion of carina are fused into a sharp—edged ridge; but those of the posterior portion are fused into a broad noded ridge or even modified, through fusion with adjacent nodes, into a series of transverse ridges. Cup elongate, asymmetrical, widest anteriorly and pointed posteriorly. Outer side of cup wider than inner; its oral surface smooth except adja- cent to the carina, where, anteriorly, it bears a row of nodes that are entirely fused into a transversely ridged platform. Posterior to this platform the outer side imay be without nodes; if present, these nodes are separated from each other although each one may be fused to an adjacent portion of the carina. Inner side of cup longer and narrower, but in other respects similar to outer side. Blade approximately twice as long as carina, massive adjacent to cup. Denticles of blade increase in size to near the anterior end, com- pressed, with one side nearly even on some specimens. Each denticle has a sharp-edged tip. Lateral view—With reference to the straight aboral side of the blade, the profile of the aboral side of the cup is concave and trends downward slightly. Summit line of blade dentate except adjacent to cup, where it may be even; that of carina somewhat irregular and curved downward toward truncated posterior end of fossil. Aboral view—Blade sharp-edged, to a point near expanded pulp cavity (i. e., cup), where it is split; its sides merge into those of expanded pulp cavity. Pulp cavity grooved along midline, its apex located near anterior end of concavity. Gnatkodus girtyl resembles G. texanus, but the two species can be identified by the ornamentation of the cup. The aboral side of G. girtyi is not figured as it is similar to that of G. teranus. Distribution: Barnett formation; upper faunal zone. A SHORTER CONTRIBUTION TO GENERAL GEOLOGY Gnathodus inornatus Hass, n. sp. Plate 14, figures 9—11 1941. Spathognathodus commutatus Branson and Mehl. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 172, pl. 5, figs. 19—22. (Date of imprint, 1940.) Holotype: U.S.N.M. 115084. Paratypes: U.S.N.M. 115085, 115086. , Type locality: 0-12, about 5,000 feet N. 60° W. of point at which Honey Creek crosses road from Mason to White’s Crossing over Llano River, Mason County, Tex.; collection 9309. Oral view—Axis straight to slightly curved laterally; it is widest near posterior end of fossil and tapers anteriorly. Carina rises high above inner and outer sides of cup. Denticles of carina tend to be fused; their tips are subcircular to elliptical in transverse section. Cup low, unornamented, and circular to sub- circular in outline; generally it extends beyond the posterior end of the carina. Blade may be as much as four times longer than carina, thickest at or below the midline of its lateral sides. Denticles of blade compressed, except at the posterior end, where they resemble those of carina. Each denticle has a sharp— edged tip. Lateral view.——Outline of fossil is nearly rectangular, the rectangularity being modified by the extension of the cup. Aboral view—Blade sharp-edged except posteriorly, where it is split; its sides merge into those of expanded pulp cavity (i. e., cup). Pulp cavity funnel-shaped, located beneath carina and posterior portion of blade, grooved along midline. Gnathodas inornatus resembles the syntypes of G’. commutatus (Branson and Mehl) from the Pitkin lime- stone of Oklahoma. These two species, however, can be identified by the shape of the cup. The cup of G. inoraatas, in oral view, is circular to subcircular in outline and generally extends posteriorly beyond the remainder of the fossil, whereas the cup of G. commutatus is elongate and pointed posteriorly. Distribution: Barnett formation; upper fauna] zone. Gnathodus texanus Roundy Plate 14, figures 15—21 Gnathodus texanus Roundy, U. S. Geo]. Survey Prof. Paper 146, p. 12, pl. 2, figs. 73, b, 88., b. Gnathodus texanus var. bicuspidus Roundy, U. S. Geol. Survey Prof. Paper 146, p. 12, pl. 2, figs. 98., b. Spathodus texomus (Roundy). Cooper, Jour. Paleontology, vol. 13, p. 416 [not pl. 42, figs. 63, 64]. [Not] Gnathodus texanus (Roundy). Cooper, J our. Paleon- tology, vol. 13, p. 388, pl. 41, figs. 26, 27. Gnathodus tezanus Roundy. Hass, Jour. Paleontology, vol. 15, pl. 15, fig. 4. Gnathodus texanus Roundy. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 173, pl. 5, figs. 23—25. (Date of imprint, 1940.) 1926. 1926. 1939. 1939. 1941. 1941. CONODONTS OF THE BARNETT FORMATION OF TEXAS ‘ 81 1941. [Not] Gnathodus texanus Roundy. Missouri School Mines and Metallurgy, Bull., no. 3, p. 2, pl. 2, figs. 8—10, 12. 1947. [Not] Gnathodus texanus (Roundy) [sic]. Mehl and Thomas, Denison Univ., Sci. Lab., Bull., vol. 47, p. 10, pl. 1, fig. 3. Holotype: By original designation, the specimen shown by Roundy, 1926, as figures 8a, b, on plate 2, U...SN M. 115090 [=U. S. G. S. Carb. cat. 4018a]. Paratypes: The specimen shown by Roundy, 1926, as figures 7a, b on plate 2, U S. N M 115092 [= U. S. G. S. Carb. cat. 4017a] and the holotype of Gnathodus texanus var. bicuspidus Roundy, U.S.N.M. 115091 [=U.S.G.S. Carb. cat. 4019a]. Hypotypes: U.s.N.M. 115093, 115094, 115095, 115096. Type locality: C-5, along road, 4.9 miles east and 0.9 mile south of the courthouse at San Saba, San Saba County, Tex.; collection 2688. ‘ Oral view—Axis essentially straight. Carina broader than oral portion of blade; it rises high above oral surface of cup. Denticles of carina fused nearly to their tips; generally these tips are slightly chevron- shaped. Cup asymmetric, widest anteriorly, and pointed posteriorly. Outer side of cup larger than inner; its oral surface smooth or ornamented with a few nodes which tend to lie near the carina. These nodes, which vary in size, may be discrete or fused to form a ridge. Inner. side of cup slightly longer than outer. Anteriorly, it supports a large pillarlike process which varies in size and shape; generally, it is as high as the carina, smooth, laterally constricted at the tip, and joined to the carina by a low ridge. Blade approx- imately twice as long as carina, most massive adjacent to cup, thickest near the aboral side. Denticles of blade increase in size anteriorly. Lateral view—With reference to straight aboral side of blade, profile of aboral side of cup is curved down- ward. Fossil increases in height anteriorly; summit line of carina irregular, that of the blade dentate. Aboml view—Aboral side of blade sharp-edged to near pulp cavity, where it is split; its sides merge into those of expanded pulp cavity (i. e., cup). Pulp cavity grooved along midline, its apex located near the anterior end of the concavity. The pillarlike process of the inner side of the cup is the distinguishing feature of G. texanus. Roundy described a variety of this species, as G. texanus var. bicuspz'dus. This variety, which is based upon a single specimen, was described as differing from G. texanus s. s. by having a nodelike process on the outer side of the cup as well as on the inner; this difference, however, is unimportant, as any large suite of specimens will show a gradation of the individuals from those entirely devoid of nodes to those bearing nodes‘of various sizes, shapes, and numbers on the outer side of the cup. Even the holotype of G. temnus possesses such a node. G. texanus var. bicuspidus is therefore regarded as being Ellison and Graves, vol. 14, within the range of variation of G. texanus. The. species is associated with G. bilineatus, from which it can be distinguished by the ornamentation of the cup. The name Gnathodus texanus (Roundy) was used by Cooper (1939, p. 388) when he transferred Polygnathus teramz Roundy to the genus Gnathodus, but, as stated on page 79 of this paper, the correct name for P. temna is believed to be G. bilineatus. Ellison and Graves (1941) have reported G. texanus Roundy from the Dimple limestone of the Marathon region of Texas, but their figured specimens do not resemble the holotype of Roundy’s species. Mehl and Thomas (1947, ‘p. 10) have stated that G. temnus (Roundy) [sic] is repre- sented by an abundance of specimens in the Fern Glen limestone of Missouri. They do not describe the species, and their figured specimen does not clearly record the characteristics of Roundy’s species. Distribution: Barnett formation; upper faunal zone. Genus HINDEODELLA Bassler. 1925 1925. Hindeodella Bassler, Geol. p. 219. Hindeodella. Bassler. Ulrich and Bassler, Mus. Proc., vol. 68, art. 12, pp. 17, 38. Hindeodella, Bassler. Staufier and Plummer, Texas Univ. Bull. 3201, pp. 32, 33. Branson and Mehl, Missouri Univ.’ Soc. America Proc., vol. 36, 1926. U. S. Nat. 1932. 1934. Hindeodella Bassler. Studies, vol. 8, no. 3, pp. 194, 195. (Date of imprint,’ . 1933.) 1941. Hindeodella Bassler. Ellison, Jour. Paleontology, vol. 15, p. 117. 1944. Hindeodella Bassler. Branson and Mehl, in Shimer and Shrock, Index fossils of'North America, p. 241. Genotype, by original designation, Hindeodella subtilz‘s Bassler, 1925. Hindeodella ensis Hass, n. sp. Plate 16, figures 19—21. 1926. Ctenognathus sp. A Roundy, U. S. Geol. Survey Prof. Paper 146, p. 16, pl. 2, fig. 3. 1941. Hindeodella sp. Hass, Jour. Paleontology, vol. 15, pl. 15, figs. 2, 3; pl. 16, fig. 6. 1941. Hindeodella sp. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 170, pl. 5, fig. 1. (Date of imprint, 1940.) Holotype: U.S.N.M. 115191. Paratypes: U.S.N.M. 115192; also, the figured specimen of Ctenognathus sp. Afigured by Roundy, 1926, U.S.N.M. 115190 [=U.S.G.S. Carb. cat. 4029a]. Type locality: G—12, about 5,000 feet N. 60° W. of point at which Honey Creek crosses the road from Mason to White’s Crossing over the Llano River, Mason County, Tex.; collection 9309. ' Unit is long, thin, and bladelike. Posterior bar slightly arched, curved inward, especially at the distal end; bar thickest near midheight, below which it is beveled and faintly lined by free edges of lamellae composing fossil. Bar denticles are of two sizes, 82 A SHORTER CONTRIBUTION TO closely set, directed posteriorly, and curved inward slightly. Larger-sized denticles sharp-edged, biconvex in transverse section with inner side slightly larger than outer. Two or three smaller-sized, needlelike denticles generally separate adjacent larger-sized ones. Main cusp compressed at base, longer, broader, and thicker than bar denticles ; in other respects main cusp is similar to larger-sized denticles. Anterior bar short, flexed inward, angled downward; its other characteristics similar to those of posterior bar. Aboral side sharp- edged except adjacent to main cusp, where it is grooved along the midline. Pulp cavity small. Distribution: Barnett formation; upper faunal zone. Hindeodella. undata Branson and Mehl Plate 16, figures 5—7 1941. Hindeodella undata Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 169, pl. 5, fig. 3. (Date of imprint, 1940.) 1941. Hindeodella sp. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 170, pl. 5, fig. 9. (Date of imprint, 1940.) ~Hypotypes: U.S.N.M. 115176, 115177, 115178. Posterior bar long, compressed at the distal end; in transverse section it is higher than wide with the inner side thicker than the outer. Aboral side may be either sharp-edged or rounded. Denticles of posterior bar are of two sizes, closely set, and normal to the bar. Larger-sized denticles curved inward, pointed, biconvex in section with inner side thicker than outer. Smaller- sized denticles similar to larger-sized ones; generally, a group of four to six smaller-sized denticles separate the adjacent larger-sized ones. Posterior bar is sinuous in oral view; it bulges inward at the base of the larger- sized denticles and outward at the base of each group of smaller-sized ones. Main cusp erect or directed slightly to the posterior, larger than bar denticles, pointed, biconvex in section, compressed, and beveled in basal portion. Anterior bar emerges from main cusp without offset; it is flexed inward more than 90° and is produced below remainder of fossil into a very short, pointed extremity. This bar supports four or five closely set, discrete, needlelike denticles. Each of these denticles curves inward slightly and may be as large as the larger- sized denticles of the posterior'bar. Midline of aboral side is grooved; faintly so on specimens with a sharp- edged aboral side and more plainly so on specimens with a broadly rounded aboral side. Pulp cavity small, pitlike. Distribution; Barnett formatibn; upper faunal zone. Genus LIGONODINA Bassler, 1925 1925. Ligonodz'na Bassler, Geol. Soc. America Proc., vol. 36, p. 219. GENERAL GEOLOGY 1926. Ligonodina Bassler. Ulrich and Bassler, U. S. Nat. Mus- Proc., vol. 68, art. 12, pp. 8, 12. Plagiodina Cooper, Geol. Soc. America Bu11., vol. 44, p. 210. Liganodina Bassler. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 1, p. 48. I dioprioniodus Gunnell, Jour. Paleontology, vol. 7, p. 265. Ligonodina Bassler. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 3, p. 198. (Date of imprint, 1933.) Ligonodina Bassler. Huddle, Bull. Am. Paleontology, vol. 21, no. 72, pp. 58—60. Ligonodz'na, Bassler. Ellison, Jour. Paleontology, vol 15, p. 114. Liganodina Bassler. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 241. Genotype, by original designation, Ligonodina pectinata Bassler, .1925. 1933. 1933. 1933. 1934. 1934. 1941. 1944. Ligonodina fragilis Bass, n. sp. Plate 15, figure 1 Holotype: U.S.N.M. 115057. Type locality: C—13, east bank of Llano River at White’s Crossing, Mason County, TeX.; collection 9312. Posterior bar straight, approximately three times higher than wide. Denticles of posterior bar discrete, either erect or directed posteriorly, pointed, biconvex in section, and, at the base, almost as wide as the bar; denticles tend to alternate in size. Main cusp pointed, biconvex in section, curved posteriorly, with greatest degree of curvature in basal portion; near the tip, main cusp may be twisted inward slightly. Basal portion of main cusp is located below level of posterior bar. Anti- cusp emerges from basal portion of anterior side of main cusp, is flexed inward, and twisted so that its pointed extremity is directed posteriorly. Anticusp supports four or five denticles ; these denticles,which are discrete, pointed, posteriorly curved, and circular to elliptical in section, decrease in size toward distal extremity. Aboral side of fossil even or rounded, grooved along mid- line, expanded beneath main cusp. This side is entirely set off from remainder of fossil by a ridge that may be much enlarged on the inner side of the main cusp and the adjacent portion of the posterior bar; else- where, generally, this ridge is poorly developed. Pulp cavity smal], pitlike. Ligonodina fragilis resembles L. tenuis Branson and Mehl but differs in that it has a long posterior bar that supports well-developed denticles instead of a short bar with very small denticles. Distribution: Barnett formation; upper faunal zone. Ligonodina roundyi Hess, n. sp. Plate 15, figures 5—9 1926. Priom'odus sp. A Roundy, U. S. Geol. Survey Prof. Paper 146, p. 11, pl. 4, fig. 9. 1926. Priom'odus sp. C Roundy, U. S. Geol. Survey Prof. Paper 146, p. 11, pl. 4, fig. 11. CONODONTS OF THE BARNETT FORMATION OF TEXAS 83 Holotype: U.S.N.M. 115065. Paratypes: The specimen of Priom'odus sp. A figured by Roundy, 1926, U.S.N.M. 115061 [=U. S. G. S. Carb. cat. 4035a]; the specimen of Priom'odus sp. C figured by Roundy, 1926, U.S.N.M. 115062 [=U.S.G.S. Carb. cat. 4025a]; also U.S.N.M. 115063, 115064. Type locality: C—13, east bank of Llano River at White’s Crossing, Mason County, Tex.; collection 9312. Unit consists of a massive main cusp, a well-formed anticusp, and a fragile posterior bar. Bar denticles minute, discrete, and, at the base, as wide as the oral side of the posterior bar. Main cusp long, stout, pointed, and curved posterior-1y with greatest degree of curvature near the base. Near the tip, the main cusp is compressed and the anterior and posterior sides are sharp—edged; toward the base, the posterior edge be— comes a faint median line in a shallow groove. The anterior edge of the main cusp trends inward gradually so as to form a sharp—edged ridge along the front inner side. This ridge continues downward along the midline of the anticusp. Basal outer side of main cusp ex— panded; inner side, posterior to above-mentioned ridge, slightly grooved. Anticusp emerges from main cusp without offset; it is short, directed downward, and flexed inward approximately 90°. Anticusp supports at least four denticles, which, in general, decrease in size toward the pointed distal extremity. Denticles of anticusp compressed, pointed, discrete, closely set, and directed upward and slightly backward. Aboral side of fossil grooved along midline. Aboral side of main cusp excavated, expanded more on outer side than on inner. Apex of pulp cavity located at junction of main cusp and anticusp. This species closely resembles Légonodi’na. typa, (Gunnell) but differs in that it has a larger main cusp and has discrete denticles on the anticusp, instead of partly fused ones. Distribution: Barnett formation; upper faunal zone. Genus LONCHODINA Bassler, 1925 Lonchodina Bassler, Geol. Soc. America Proc., vol. 36, p. 219. Lonchadina Bassler. Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, pp. 30, 31. Lonchodina. Bassler. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 2, p. 136. Lonchodina Bassler. Huddle, Bull. Am. Paleontology, vol. 21, no. 72, p. 81. ‘ Lonchodina Bassler. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 243. Genotype, by original designation, Lonchadina Bassler, 1925. Lonchodina paraclarki Bass, n. sp. 1925. 1926. 1933. 1934. 1944. typicalis Plate 16, figures 15, 16 Holotype: U.S.N.M. 115186. Paratype: U.S.N.M. 115187. Type locality: C—12, about 5,000 feet N. 60° W. of point at which Honey Creek crosses road from Mason to White’s Cross— ‘ ing over Llano River, Mason County, Tex. ; collection 9309. Main cusp long, pointed, and directed forward, with greatest degree of curvature near the base. Two sharp edges divide main cusp into a smaller inner side and a larger outer one. Inner. side of cusp broadly convex throughout its entire length. Outer side convex, its basal portion expanded posteriorly. A groove, which may be faint, is located adjacent to the posterior sharp edge on the basal portion of the outer side of cusp. Anterior sharp edge of cusp continuous with midline of anterior bar. Anteriorbar straight, shorter than main cusp, and, with reference to posterior bar, is directed downward. Anterior bar of young specimen fragile and compressed; that of a mature one is stout, higher than wide, and is tapered to a pointed distal extremity. In transverse section, this bar is broadest along aboral side; its lateral sides converge orally and merge into the denticles. Anterior bar supports two to four denticles which are discrete, closely set, curved posteriorly, pointed, compressed, and biconvex in section. Pos- terior bar is shorter than anterior bar; it supports two to three denticles, which, though normal to bar, curve toward outer side of fossil. Other characteristics of posterior bar and its denticles similar to those of den- ticulated anterior bar. Aboral side of fossil broadest beneath main cusp from where it tapers to pointed extremities. Midline of aboral side grooved. Pulp cavity occupies entire under side of main cusp and is ' located mainly on outer side of midline of fossil. This species is distinguishable from Ligonodina clarki (Gunnell) in that it tends to be more massive, its an- terior bar is broadest along the unbeveled aboral side, and the denticles of its anterior bar are discrete. Distribution: Barnett formation; upper faunal zone. Genus LONCHODUS Pander, 1856 1856. Centrodus Pander [not Giebel, 1848], Monographie der fossilen Fische des silurischen Systems der russisch- baltischen Gouvernements, p. 31. Lonchodus Pander, Monographie der fossilen Fische des silurischen Systems der russisch-baltischen Gouverne- ments, p. 80. Lonchodus Pander. Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, p. 42. Lonchadus Pander. Roundy, U. S. Geol. Survey Prof. Paper 146, p. 15. Lonchodus Pander. Bull. 3201, p. 37. Lonchodus Pander. vol. 46, p. 144. 1856. 1926. 1926. 1932. Stauffer and Plummer, Texas Univ. 1935. Staufl'er, Geol. Soc. America Bull., 1935. Lonchodus Pander. Staulfer, Jour. Paleontology, vol. 9, p. 607. 1945. Lonchodus Pander. Youngquist, Jour. Paleontology, vol. 19, p. 362. Genotype, by subsequent designation of Ulrich and Bassler, 1926, Centrodus simplex Pander, 1856. 84 . A SHORTER CONTRIBUTION TO GENERAL GEOLOGY In 1856, Pander (p. 31) erected the genus Centrodus for some conodont fragments that he thought might have “paleontologic” [stratigraphic] value. Upon learning that the name Centrodus was preoccupied, Pander '( 1856, p. 80) changed the name of the genus to Lonchodus. A free translation of Pander’s description reads: Lonchodus “includes large, slender, pointed, lamellose teeth, alone or alternating with smaller ones of varying size and number, which rest upon a horizontal or convex base.” Under Lonchodus, Pander described and figured four types of fragments, and with two of these, Lonchodus simplex and Lonchodus lineatus, Roundy (1926, p. 15) identified some fragments from the Barnett formation. Lonchodus lineatus (Pander) Plate 14, figures 1, 2 Centrodus lineatus Pander, Monographje der fossilen Fische des silurischen Systems der russisch-baltischen Gouvernements, p. 31, pl. 2a, fig. 9. Lonchodus lineatus (Pander). Pander, Monographie der fossilen Fische des silurischen Systems der russisch- baltischen Gouvernements, p. 80. Polygnathus dubia Hinde [part], Geol. Soc. London Quart. Jour., vol. 35, pp. 362, 363, pl. 16, figs. 13, 14, [not figs. 6—12, 15—18]. , Centrodus lineatus Pander. Hinde, Nat. History Soc. Glasgow Trans, 11. ser., vol. 5, p. 341, pl. 9, figs. 13, 14. Lonchodusi7 lineatus (Pander). Roundy, U. S. Geol. Survey Prof. Paper 146, p. 15, pl. 3, figs. 7, 8. Hindeodella lineata (Pander). Holmes, U. S. Nat. Mus. Proc., vol. 72, art. 5, p. 11. Hindeodella cf. H. lineata (Pander). Currie, Geol. Soc. Glasgow Trans, v01. 19, pt. 3, p. 432, pl. 3, fig. 3 [not figs. 2, 2a=Hindeodella sp.]. Hindeodella lineata (Pander). Demanet, Mus. royal histoire nat. Belgique Mem., no. 84, p. 162, pl. 14, figs. 12, 13(?), 14. 1939. [Not] Hindeodella lineata (Pander). Cooper, Jour. Pale- ontology, vol. 13, p. 389, pl. 46, figs. 28, 31. Hypotypes: The specimens figured by Roundy, 1926, as fig. 8, pl. 3, U.S.N.M. 115076 [=U.S.G.S. Carb. cat. 4031a] and as fig. 7, pl. 3, U.S.N.M. 115077 [=U.S.G.S. Carb. cat. 4030a]. 1856. ‘1856. 1879. 1900. 1926. 1928. 1937. 1938. Bar elongate, denticulated, slightly bowed inward, and subcircular in transverse section. Aboral third of bar beveled, faintly lined longitudinally. Bar denticles are of two sizes; three to six smaller-sized denticles sep- arate adjacent larger-sized ones. All denticles closely set, posteriorly directed, curved inward, pointed, sharp- edged; in section, inner side of each denticleis thicker than outer side. Aboral side grooved. Even though the fragments that Roundy identified as Lonchodus? lineatus are probably hindeodellids, no attempt has been made to identify them because there is nothing of stratigraphic or nomenclatorial value to be gained thereby. Pander (1856, p. 31) intended that Lonchodus Iineatus contain only indeterminable frag- ments. His description of the species is “a row of teeth, crowding one another, that rises from a linear base; of these teeth, generally every fourth one is larger than the remaining.” HOWever, one cannot assume, as Pander did, that L. lineatus might possibly have “pale— ontologic” [stratigraphic] value because his generalized description applies equally Well to the bar fragments of so many species, that the total stratigraphic range is great enough to nullify any value the category might otherwise have. Some workers have not followed Pander in regarding L. lineatus as a catch—all species as specimens less frag- mentary than Pander’s have been assigned to it. Hinde (1879, p. 362), for example, identified whole specimens as Centrodus lineatus (i. e., L. lineatus). Other students including Holmes (1928, p. 11) have transferred L. lineatus to the genus Hindeodella; their reason for favor- ing this change was due, no doubt, to the fact that Pander’s fragmentary specimen closely resembles a hindeodellid bar. In the present paper, hOWever, the View is held that inasmuch as the anterior and posterior extremities of the holotype of L. lineatus are not known, it is impossible to prove a relationship with Hindeodella, so L. lineatus rather than Hindeodella lineata is consid— ered to be the correct name. Although Holmes effected a generic change from Lonchodus to Hindeodella, she probably did consider the category to be a catch-all, as witness her synonymy which contains only two cita- tions; both of which refer to fragmentary specimens. These entries are: Centrodus lineatus Pander, Hinde, 1900 (two briefly described and poorly figured barlike fragments from the Carboniferous of western Scotland) and Lonchodus? lineatus (Pander), Roundy, 1926 (the two fragments redescribed in this paper). Recently, Cooper (1939, p. 389) described and figured some specimens from the lower Mississippian of Oklahoma as Hindeodella lineata. He, like Holmes, placed only Hinde’s and Roundy’s fragmentary specimens in his synonymy but inasmuch as the specimens he described and figured are much more complete than Pander’s holotype, he appears to have assigned characteristics to L. lineatus that are not evident from either Pander’s description or illustration. Currie (1937, p. 432), also, has attempted to assign characteristics to L. lineatus. She has stated in her paper on the fauna of the Car— boniferous Skipsey’s Marine Band of Scotland that Hindeodella of. H. lineata is the most common conodont species; a species that she would have named L. lineatus had not- one of the specimens possessed characteristics of generic significance. It is very possible that they who have attempted to augment the characteristics of L. lineatus have studied specimens that are not closely related to Pander’s frag— mentary fossil, and it is therefore suggested that the CONODONTS OF THE BARNETT FORMATION OF TEXAS 85 category be employed as Pander had intended, that is, as a catch-all. On the other hand, if L. lineatus is to be regarded as a category for specifically related speci- mens, it certainly follows that the additional charac— teristics of such a poorly known category can be estab— lished with reasonable certainty only by comparing Pander’s specimen with better preserved material from the type locality at Tula, U. S. S. R. Until this is done, any specific identification with L. lineatus, as Well as attendant correlations based on it, can be easily challenged. Therefore, in this paper, L. linealus is regarded merely as a convenient butmeaningless cate- gory for fragments that resemble the one Pander described and figured in 1856. Distribution: Described specimens are from Barnett forma- tion; upper faunal zone. Lonchodus simplex (Pander) Plate 14, figure 7 1856. Centrodus simplex Pander, Monographie der fossilen Fische des silurischen Systems der russisch-baltischen Gou- vernements, p. 31, p1. 2a, figs. 2, 3, 5, 6. Lonchodus simplex (Pander). Pander, Monographie der fossilen Fische des silurischen Systems der russisch- baltischen Gouvernements, p. 80. Polygnalhus dubia Hinde [part], Geol. Soc. London Quart. Jour. vol. 35, pp. 362, 363, pl. 16, figs. 10, 11 [not figs. 6—9, 12—18]. ‘ Lonchodus simplex (Pander). Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, p. 42. Lonchodus simplex (Pander). Roundy, U. S. Geol. Survey Prof. Paper 146, p. 15, pl. 3, figs. 1—5. Lonchodus simplex (Pander). Gunnell, J our. Paleontology vol. 5, p. 248, pl. 29, figs. 13 ,14 [misprinted in text as pl. 1, figs. 10, 11]. Lonchodus simplex? (Pander). Staufler and Plummer, Texas Univ. Bull. 3201, p. 38, pl. 2, fig. 1. Lonchodus simplex? (Pander). Gunnell, Jour. Paleon- tology, vol. 7, p. 269, pl. 31, fig. 2 [misprinted in text as pl. 1, fig. 2]. Polygnathus dubia Hinde. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 2, pl. 11, fig. 19; pl. 12, fig. 3. Synprioniodina cf. S. simplex (Pander). Demanet, Mus. royal histoire nat. Belgique Mém., no. 84, p. 162, pl. 14; figs. 8, 9 [not figs. 10, 11]. Lonchodus simplex (Pander). Cooper, Jour. Paleontology, vol. 13, p. 392, pl. 46, figs. 34, 38. 1941. Lonchodus simplex (Pander). Ellison and Graves, Mis- souri School Mines and Metallurgy, Bull., vol. 14, no. 3, p. 3, pl. 1, fig. 21. Hypotype: The specimen figured by Roundy, 1926, as fig. 5, pl. 3, U.S.N.M. 115082 [=U.S.G.S. Carb. cat. 4026a]. 1856. 1879. 1926. 1926. 1931. 1932. 1933. 1933. 1938. 1939. This description is based upon a single fragmentary specimen that lacks both the anterior and posterior extremities. The bar is straight and smooth. In transverse section, it is higher than wide, with the oral side roundly arched and with the lateral sides gradually converging toward the aboral edge Where they flare ,broken ofl’ adjacent to the bar. slightly. The aboral side is a wide, V-shaped groove. This fragment supports five denticles ; the posterior two are long and pointed but the anterior three have been These denticles are discrete, sharp-edged, and directed posteriorly; their sides are convex, and, at the base, they are as wide as the bar. Pander’s description of Lonchodus simplex is trans- lated as “long, sharp, pointed, straight or bent teeth that stand vertically on a common horizontal base.” Pander believed his category might have “paleontol— ogic” [stratigraphic] value, but today its worth is vitiated by the knowledge that L. simplex contains fragments whose ages differ greatly. Distribution: Described specimen is from Barnett formation; upper faunal zone. Genus METALONCHODINA Branson and Mehl, 1941 1941. Metalonchodina Branson and Mehl, Jour. Paleontology, vol. 15, pp. 105, 106. 1944. Metalonchodina Branson and Mehl. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 243. Genotype, by original designation of Branson and Mehl, 1941, Prioniodus bidenlatus Gunnell, 1931. Metalonchodina sp. A Plate 16, figures 17, 18 Figured specimens: U.S.N.M. 115188, 115189. The following description is based upon a suite of fragmentary specimens. In oral view the species tends to be flexed outward near the anterior extremity and inward near the posterior end. Anterior bar is short, thickest adjacent to the pulp cavity, compressed and pointed at the distal extremity; in lateral view this bar is straight or curved downward. Anterior bar sup- ports one or more denticles which are directed slightly forward, curved inward, pointed, compressed, and bi- convex in transverse section. Posteriormost of these denticles is approximately twice as large as main cusp; its inner side, especially adjacent to the main cusp, is much larger than its outer side. Posterior bar fragile, approximately as high as wide, and, with reference to the anterior bar, is flexed downward about 90°. Den— ticles of posterior bar curved upward; other character- istics similar to those of anterior bar. Main cusp simi- lar to bar den ticles except that the inner side is enlarged especially in the basal portion. Aboral side of fossil with narrow groove along midline. Pulp cavity deep, coniform, and located chiefly on inner side of midline. Distribution: Barnett formation; upper faunal zone. Genus PALMATOLEPIS Ulrich and Bassler, 1926 1926. Palmatolepis Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, pp. 44, 49. 86 1934. Palmatolepis Ulrich and Bassler. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 3, p. 233. (Date of imprint, 1933.) \ 1934. Palmatolepis Ulrich and Bassler. Huddle, Bull. Am. Paleontology, vol. 21, no. 72, p. 106.- 1944. Palmatolepis Ulrich and Bassler. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 245. Genotype, by original designation, Palmatolepis perlobata Ulrich and Bassler, 1926. Palmatolepis glabra Ulrich and Bassler Plate 15, figure 4 Palmatolepis glaber Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, p. 51, pl. 9, figs. 18—20. Polygnathus sp. A Roundy, U. S. Geol. Survey Prof. Paper 146, p. 14, pl. 3, figs. 12a, b. Palmatolepis elongate Holmes, U. S. Nat. Mus. Proc., vol. 72, art. 5, p. 33, pl. 11, fig. 13. Palmatolepis glabra Ulrich and Bassler. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 3, pp. 233, 234, pl. 18, figs. 9, 22, 26. (Date of imprint, 1933.) Palmatolepis elongate Holmes. Huddle, Bull. Am. Pal- eontology, vol. 21, no. 72, p. 108, pl. 9, figs. 8—10. 1926. 1926. 1928. 1934. 1934. 1935. [?]Palmatolepis elongata Homes. Cooper, Jour. Pal- eontology, vol. 9, p. 314, pl. 27, fig. 40. 1941. [?]Palmatolep1§s glabra? Ulrich and Bassler. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, p. 192, pl. 7, fig. 13. (Date of imprint, 1940.) [?]Palmatolepis cf. P. glabra Ulrich and Bassler. Bran- son and Mehl, Dension Univ., Sci. Lab., Bull., vol. 35, p. 192, pl. 7, figs. 15, 16. (Date of imprint, 1940.) [?]Palmatolepis glabra Ulrich and Bassler. Cooper, in Cooper and Sloss, Jour. Paleontology, vol. 17, pl. 29, figs. 5, 36. Palmatolepis glabra Ulrich and Bassler. Bond, Ohio Jour. Sci., vol. 47, no. 1, p. 33, pl. 2, fig. 25. Palmalolepis glabra Ulrich and Bassler. Thomas, Geol. Soc. America Bull., vol. 60, pl. 1, fig. 19. Hypotype: The specimen of Polygnathus sp. A figured by Roundy, 1926, U.S.N.M. 115060 [=U.S.G.S.Carb. cat. 4014a]. The specimen that Roundy described and figured as Polygnathus sp. A is a fragment of Palmatolepis glabm. 1941. 1943. 1947. 1949. This species does not appear to range naturally above the Upper Devonian and its presence in the Barnett fauna is therefore regarded as having been the result of reworking. The following description is based upon a suite of well-preserved specimens from the Upper Devonian. Oral view.~—An elongate asymmetric unit. Plate upturned posterior to the large azygous node; margin of plate smooth. Carina straight or concave toward outer platform, composed of small fused denticles, some of which are nodelike; it may be indistinct at posterior end of plate. Blade approximately twice as long as carina, concave as well as inclined slightly toward inner side of fossil. Axis divides plate into platforms of unequal size that are ornamented with numerous reticu- Iating rows of granules. Inner platform extends entire length of fossil; it is slightly broader than the outer A SHORTER CONTRIBUTION TO GENERAL GEOLOGY platform and has the sigmoid curvature of its free edge interrupted in some specimens by a small lobe near the azygous node. Outer platform terminates abruptly halfway between azygous node and the anterior end of the fossil. Anterior to the azygous node the outer platform is arched and its margin is upturned to form a ridge or parapet that is as high as the adjacent portions of the blade. Lateral view—With reference to the aboral side of the blade, the plate is upturned posterior to the azygous node. Summit line of axis dentate or irregular; in general, it increases in height anteriorly. Aboral view—Midline sigmoid, keeled except adjacent to the extremely small pulp cavity which is located beneath the azygous node. Distribution: Figured specimen is considered to be a reworked Upper Devonian fossil. Genus POLYGNATHUS Hinde. 1879 1879. Polygnathus Hinde, Geol. Soc. London Quart. Jour., vol. 35, p. 361. Polygnathus Hinde. tology, p. 520. Polygnathus Hinde. Bryant, Buffalo Soc. Nat. Sci. Bull., vol. 13, no. 2, pp. 22—24. Polygnathus Hinde. Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, pp. 43—45. Polygnathus Hinde. Roundy, U. S. Geol. Survey Prof. Paper 146, p. 13. Polygnathus Hinde. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 2, p. 146. Polygnathus Hinde. Huddle, Bull. Am. Paleontology, vol. 21, no. 72, p. 94. Macropolygnathus Cooper, Jour. Paleontology, vol. 13, p. 329. 1944. Polygnathus Hinde. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 245. Genotype, by subsequent designation of Miller 1889, Poly- gnathus dubia Hinde. 1879. The type of Polygnathus dubia designated by Roundy, 1926, as fig. 17 on pl. 16 of Hinde’s 1879 publication. 1889. Miller, N. Am. Geology and Paleon- 1921. 1926. 1926. 1933. 1934. 1939. Polygnathus taffl Roundy Plate l4,figure 8 1926. Polygnathus tafii Roundy, U. S. Geol. Survey Prof. Paper 146, p. 13, pl. 3, figs. 118., b. Holotype: The specimen shown by Roundy, 1926, as figs. 11a, b, pl. 3, U.S.N.M. 115083 [=U. S. G. S. Carb. cat. 4020a]. Type locality: 0-9, 5% miles west of Lampasas, Burnet County, Tex.; collection 7016 (green). Oral view—This description is based upon a single fragmentary specimen that lacks both the anterior and posterior extremities. Plate elongate; its unbroken margin crenate. Denticles of carina compressed and fused nearly to their pointed sharp-edged tips. Outer platform slightly larger than inner; both platforms low at posterior end and upturned throughout most of their length so as to form smooth-bottomed troughs With CONODONTS OF THE BARNETT FORMATION OF TEXAS the carina. Troughs increase in depth anteriorly. Margin of inner platform nearly straight; that of outer, slightly convex. Oral surface of platforms minutely pitted and marked by faint transverse ridges. Lateral view—Summit line of carina dentate. Aboral side angled downward immediately posterior to pulp cavity. Oral edge of inner platform nearly straight and on level with summit line of carina; that of outer platform is arched above carina. Aboml view—Plate smooth; platforms pitch steeply from the midline. Pulp cavity large, elliptical, mod- erately deep, and set off from anterior portion of plate by a thick rounded margin. This margin merges posteriorly into the sharp-edged keel of the plate. The holotype of Polygnathus tafi has been damaged since Roundy described it. A comparison of Roundy’s figures of the type with the one in this paper shows that a portion of the anterior end has been broken away and lost. Because of its fragmentary nature P. tafii is not compared with any other species of Polygnathus. P. tafii moreover, has no stratigraphic value as it is based upon a single specimen that appears to have been. reworked into the fauna of the Barnett formation. According to Ellison (1946, p. 94), the genus Polyg— nathus does not range above the Osage group of the Mississippian. Distribution: Described specimen is considered to be a reworked fossil. Its stratigraphic position not known. Genus PRIONIODUS Pander, 1856 1856. Priom'odus Pander, Monographie der fossilen Fische des silurischen Systems der russisch—baltischen Gouverne< ments, p. 29. Prioniodus Pander. tology, p. 520. Priom'odus Pander. Ulrich and Bassler, U. S. Nat. Mus. Proc., vol. 68, art. 12, pp. 8, 9. Prioniodus Pander. Roundy, U. S. Geol. Survey Prof. Paper 146, p. 10. Priom'odus Pander. Cooper, Geol. Soc. America Bull., vol. 44, p. 210. ‘ Priomlodus Pander. Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 2, pp. 129, 130. Prioniodus Pander. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 241. Genotype, by subsequent designation of Miller, 1889, Prioni- odus elegans Pander, 1856. 1889. Miller, N. Am. Geology and Paleon- 1926. 1926. 1933. 1933. 1944. Prioniodus inclinatus Bass, n. sp. Plate 16, figures 10—14 1926. Priom'odus sp. D Roundy [part], U. S. Geol. Survey Prof. Paper 146, p. 11, pl. 4, fig. 12 [not figs. 13a, b=Genic— ulatus claviger (Roundy)]. Holotype: U.S.N.M. 115182. Paratypes: The specimen Priom'odus sp. D, shown by Roundy, 1926, as fig. 12 on pl. 4, U.S.N.M. 115183 [=U.S.G.S. Carb. cat. 4037a];a1so U.S.N.M. 115181, 115184, 115185. 87 Type locality: 0—15, about 2,500 feet N. 88° W. of southwest bank of Llano River at White’s Crossing, Mason County, Tex.; collection 9310.’ Posterior bar of unknown length—presumedly as long as main cusp—straight to slightly curved inward. In transverse section posterior bar is approximately as high as wide, broadest at the aboral side; the inner side is thicker than the outer. Bar denticles directed for— ward, curved inward, pointed, and biconvex in section with the inner side thicker than the outer. These denticles may be discrete or fused, and, at the base, each one is as wide as the bar. Main cusp weakly joined to posterior bar, bowed inward at the base, directed for- ward, pointed, biconvex in section with inner side enlarged, especially adjacent to the posterior bar. The pointed basal projection of the main cusp is flexed outward slightly and may bear partly fused denticles along its anterior side. Midline of aboral side grooved. Pulp cavity a large, coniform concavity located beneath posterior portion of main cusp. Anterior to pulp cavity, basal projection of main cusp may be slightly excavated. Distribution: Barnett formation; upper faunal zone. Prioniodus ligo Hass, n. sp. Plate 16, figures 1—3 1926. Priom'odus peracutus Hinde. Roundy [part], U. S. Geol. Survey Prof. Paper 146, p. 10, pl. 4, figs. 7, 8 [not fig. 6= lectotype of Priom'odus pcracutus Hinde]. Holotype: U.S.N.M. 115172. Paratypes: The specimens shown by Roundy, 1926, as fig. 7, pl. 4, U.S.N.M. 115174 [=U.S.G.S. Carb. cat. 4023a] and as fig. 8, pl. 4, U.S.N.M. 115173 [=U.S.G.S. Carb. cat. 4022a]. Type locality: C—12, about 5,000 feet N. 60° W. of point at which Honey Creek crosses road from Mason to White’s Crossing over Llano River, Mason County, Tex.; collection 9317. Posterior bar curved inward; its aboral portion is beveled and finely lined by free edges of lamellae composing fossil. In tranverse section, bar is higher than wide, with the inner side thicker than the outer. Denticles of bar closely set, normal to bar, curved in- ward slightly, pointed, and biconvex in section with the inner side thicker than the outer. In lateral view, the main cusp, together with the basal projection, forms a massive, triangularly shaped unit that is pointed at the extremities, broadest and thickest adjacent to the posterior bar, and bowed inward slightly. Anterior and posterior sides of cusp sharp—edged and nearly straight; aboral side of cusp slightly convex. Outer side of cusp evenly rounded; inner side, adjacent to the anterior edge is compressed, but posterior to this area the inner side is thicker. The beveled and striated characteristics of the aboral portion of the posterior bar continue to the tip of the anticusp. Aboral side of fossil grooved along midline. Pulp cavity small, pit- like, located at junction of posterior bar and cusp. 88 In gross features Prioniodus ligo closely resembles P. scitulus Branson and Mehl, but differs in that it is larger and has the aboral side of its main cusp grooved instead of excavated. P. ligo resembles the lectotype of P. peracutus Hinde but differs in having many constant characteristics that are not evident from either Hinde’s description or figure.» Distribution: Barnett formation; upper faunal zone. Prioniodus roundyi Hass, n. sp. Plate 15, figures 2, 3 1926. Prioniodus sp. B Roundy, U. S. Geol. Survey Prof. Paper 146, p. 11, pl. 4, fig. 10. Holotype: U.S.N.M. 115058. Paratype: The specimen Priom'odus sp. B, shown by Roundy, 1926, as fig. 10, pl. 4, U.S.N.M. 115059 [=U.S.G.S. Carb. cat. 4024a]. , Type locality: C—15, about 2,500 feet N. 88° W. of the south- west bank of the Llano River at White’s Crossing, Mason County, Tex.; collection 9310. Posterior bar fragile, slightly sinuous, compressed, and approximately as long as main cusp. In trans- verse section, posterior bar is widest immediately above the aboral side; inner side thicker than the outer. Bar denticles short, slender, appressed to near their pointed sharp-edged tips, normal to bar, and curved inward slightly. Main cusp is flexed inward slightly at its junction with the posterior bar; it is also directed for- ward, bowed inward, compressed near its pointed tip, and biconvex in section, with the inner side thicker than the outer. The basal projection of the cusp extends below level of posterior bar; its pointed extremity is flexed outward. Anterior side of cusp may be sharp- edged or rounded. In lateral view, anterior side is faintly sigmoid, with the basal projection curved back- ward; posterior side of cusp slightly convex; the aboral side is concave. Aboral side of fossil grooved. Pulp cavity a coniform pit located at junction of cusp and posterior bar; anterior to pulp cavity, the aboral side of the cusp is troughlike. Priom‘odus roundyi resembles P. scitulus Branson and Mehl; its main cusp, however, is directed forward and is flexed inward at its junction with the posterior bar whereas that of P. scitulus is erect and does not appear to be flexed inward. Cooper (1939, p. 405) has placed Prioniodus sp. B of Roundy, 1926 in synonymy with P. oligus Cooper. Roundy’s fragmentary speci- men is conspecific with the holotype of P. roundyi and differs from P. oligus as follows: the anterior side of the cusp of P. roundyi is faintly sigmoid in lateral view and its inner side is not greatly enlarged adjacent to the posterior bar, whereas the anterior side of the cusp of A SHORTER CONTRIBUTION TO GENERAL GEOLOGY P. oligus is convex in lateral view and its inner side is enlarged adjacent to the posterior bar. Distribution: Barnett formation; upper fauna] zone. Prioniodus singularis Hass, n. sp. ‘ Plate 16, figure 4 Holotype: U.S.N.M. 115175. Type locality: C—12, about 5,000 feet N. 60° W. of point at which Honey Creek crosses road from Mason to White’s Cross— ing over the Llano River, Mason County, Tex; collection 9309 Posterior bar compressed, shorter than main cuSp, adjacent to which it is flexed inward between 45° and 90°. In lateral view bar is highest at the anterior end from where it tapers to a pointed distal extremity. Denticles of the bar gradually decrease in size pos- teriorly; they are closely set, erect or directed slightly forward, curved inward, pointed, and biconvex in section. With reference to the posterior bar the main cusp is directed forward; in lateral view it is an elongate, triangularly shaped unit which is pointed at the ex- tremities, broadest and thickest adjacent to the pos- terior bar, and bowed inward slightly. The anterior and posterior sides of the cusp are sharp-edged and nearly straight; the aboral side is slightly convex. In transverse section the cusp is biconvex with the inner side thicker than the outer. Anterior-most one or two denticles of posterior bar may be almost entirely incorporated into the main cusp. Aboral side of fossil grooved along the midline. Pulp cavity very small, located near the posterior end of the main cusp. Aboral portion of lateral sides of fossil beveled and lined by free edges of lamellae of fossil. Above the pulp cavity, on the inner side, the above—mentioned beveled area is conspicuously arched. Prioniodus sfngularis differs from P. ligo in that it is less massive, has a shorter basal projection, and has a main cusp which, with reference to the posterior bar, is directed forward instead of being erect. The strati- graphic range of P. singularis seems to be restricted, as it has been found only in collections from the top- most beds of the Barnett formation. Distribution: Barnett formation; upper faunal zone. Genus ROUNDYA Hess, :1. gen. Genotype, here designated, Roundya barnettana Hass. A bilaterally symmetrical unit consisting of a den- ticulated anterior arch which is surmounted by a large main cusp, and a denticulated posterior bar which is joined to the basal posterior side of the main cusp. Denticles of posterior bar and anterior arch discrete. Main cusp erect or curved posteriorly. Pulp cavity large, located beneath main cusp. CONODONTS OF THE BARNETT FORMATION OF TEXAS Roundya is proposed for those species, formerly assigned to Trichonodella, that have a ‘denticulated posterior bar. The reason for this emendation is given on page 90. In addition to the species described in this paper, the new genus includes the following: Trichognathus laminata Branson and Mehl, 1934; Trichognathas separata Branson and Mehl, 1934; Trichognathus tumida Branson and Mehl, 1934; Idio- prioniodus striatus Gunnell, 1933; Priomlodus mis- soum'ensis Gunnell, 1931; Prioniodus subacodus Gun- nell, 1931 ; Trichonodella brassfieldensis E. B. Branson and C. C. Branson (name valid as of July 1948); Trichonodella? edentata E. B. Branson and C. C. Branson (name valid as of July 1948); and Trichonodella carinata E. B. Branson and C. C. Branson (name valid as of July 1948). The new genus differs from Hibbardella in that it has a large, rather than a very small sized, pulp cavity. Roundya barnettana Hass, n. sp. Plate 16, figures 8, 9 U.S.N.M. 115179. Paratype: U.S.N.M. 115180. Type locality: C—15, about 2,500 feet N. 88° W. of the south— west bank of the Llano River at White’s Crossing, Mason County, Tex; collection 9310. . Holotype: Main cusp stout, pointed, curved posteriorly, with greatest curvature immediately above the enlarged base. Sharp-edged, lateral ridges divide main cusp into anterior and posterior portions; these ridges continue downward along each limb of anterior arch. In trans- verse section, anterior to the above-mentioned lateral ridges, cusp is broadly convex; posterior to these same ridges, it is also convex and, near the base, is expanded and extended posteriorly. Posterior side of main cusp has a groove adjacent to each of the above-mentioned lateral ridges; a groove may be present also along the basal portion of the posterior midline. Limbs of anterior arch about as long as main cusp from which they emerge without offset; each limb is flexed laterally immediately beneath the main cusp and is curved back— ward slightly throughout its length. In transverse section each limb of anterior arch is nearly circular adjacent to the main cusp but is slightly broader than high throughout most of its length; the greatest width is along the aboral side. Denticles of anterior arch well-formed, discrete, pointed, sharp-edged, and bicon- vex in transverse section with posterior side slightly thicker than anterior side. Each denticle tends to curve upward as well as backward. Length of posterior bar not known; adjacent to the main cusp it is broader than high with the lateral sides converging orally. Denticles of posterior bar erect, pointed, compressed, and biconvex in section. Aboral side of posterior bar is broadly grooved; that of each limb of anterior arch 89‘ is rounded and grooved along its midline. Aboral side of main cusp excavated, ovate in outline. Pulp cavity large, coniform. Prioniodus subacodus Gunnell, a species that Ellison (1941, p. 118) placed in the genus Hibbardella, is as- signed by the writer to Roandya. This species re- sembles R. bametta'na but is less massive. Distribution: Barnett formation; upper faunal zone. Genus SUBBRYANTODUS Branson and Mehl, 1934 1934. Subbryantodus Branson and Mehl, Missouri Univ. Studies, vol. 8, no. 4, p. 285. (Date of imprint, 1933.) 1944. Subbryantodus Branson and Mehl. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 244. Genotype, by original designation, Subbryantodus arcuatus Branson and Mehl, 1934. Subbryantodus roundyi Hess, n. sp. Plate 14, figures 3—6 1926. Ctenognathus sp. B Roundy, U. S. Geol. Survey Prof. ,. Paper 146, p. 16, pl. 2, figs. 4, 5. Holotype: U.S.N.M. 115079. Paratypes: The specimens of Ctenognathus sp. B, figured by Roundy, 1926, as fig. 4, pl. 2, U.S.N.M. 115080 [=U.S.G.S. Carb. cat. 4032a]; fig. 5, pl. 2, U.S.N.M. 115081 [=U.S.G.S. Carb. cat. 4033a]; and U.S.N.M. 115078. Type locality: 0—15, about 2,500 feet N. 88°W. of the south- west bank of the Llano River at White’s Crossing, Mason County, Tex; collection 9310. Oral view—Unit compressed, bladelike, broadest at pulp cavity, from where it tapers toward the extremi- ties; it may be straight but generally is bowed inward adjacent to the pulp cavity and outward near the distal extremities. Lateral view—Posterior blade may be only half as long as anterior blade. Its denticles are either erect or directed posteriorly and are closely set; each one has a pointed, sharp-edged tip and is biconvex in transverse ‘ section. Anterior blade, with reference to the posterior blade, may be angled downward more than 45°. Denticles of anterior blade directed upward; in other respects similar to denticles of posterior blade. Sup- pression and regeneration of denticles common. Apical denticle directed posteriorly; generally, it is larger but in other respects it is similar to blade denticles. Aboral view—Aboral side of fossil sharp-edged at the extremities but grooved along the midline adjacent to the pulp cavity. Pulp cavity elliptical in outline; its longer axis makes an acute angle with the inner posterior side of the fossil. Distribution: Barnett formation; upper faunal zone. Genus TRICHONODELLA Branson and Mehl, 1948, emend. Has: 1933. Trichognathus Branson and Mehl, Missouri Univ. Studies vol. 8, no. 1, p. 36. 90 A SHORTER CONTRIBUTION TO GENERAL GEOLOGY 1935. Trichognethus Branson and Mehl. Staufier, Geol. Soc. America Bull., vol. 46, p. 155. Trichognathus Branson‘and Mehl. Branson and Mehl, Denison Univ., Sci. Lab., Bull., vol. 35, pp. 175, 176. (Date of imprint, 1940.) Trichognethus Branson and Mehl. Branson and Mehl, in Shimer and Shrock, Index fossils of North America, p. 241. Trichonodelle Branson and Mehl, Jour. Paleontology, vol. 22, p. 527. _ Genotype, by original designation and by Trichognathus prime Branson and Mehl, 1933. 1941. 1944. 1948. monotypy, A bilaterally symmetrical unit, consisting of a den- ticulated arch that is surmounted by a posteriorly curved, main cusp. Pulp cavity located beneath main cusp. Basal portion of main cusp may be enlarged and extended posteriorly. In “Index fossils of North America,” Branson and Meh] (1944, p. 241) have cited Trichognethus sym- metrice Branson and Mehl from the Bainbridge lime- stone (Silurian) of Missouri as the genotype of Trichog- nethus (= Trichonodelle of present report); the geno- type, as stated above, is Trichognethus prime Branson and Mehl, from the Harding sandstone (Ordovician) of Colorado. T. prime is based on a single fragmentary conodont that differs from most of the species pre— viously assigned to the genus by lacking a denticulated posterior bar. 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Glasgow Trans, vol. 5, new sen, pt. 3, pp. 338—346, pls. 9, 10. - HOLMES, G. B., 1928, A bibliography of the conodonts with descriptions Of early Mississippian species: U. S. Nat. Mus. Proc., vol. 72, art. 5, 38 pp., 11 pls. HUDDLE, J. W., 1934, Conodonts from the New Albany shale of Indiana: Bull. Am. Paleontology, vol. 21, no. 72, 136 pp., 12 pls., 3 figs. MEHL, M. G., and THOMAS, L. A., 1947, Conodonts from the Fern Glen of Missouri: Denison Univ., Sci. Lab., Bull., vol. 40, pp. 3—20, pl. 1. MILLER, A. K., and YOUNGQUIST, WALTER, 1948, The cephalopod fauna of the Mississippian Barnett formation of central Texas: Jour. Paleontology, vol. 22, pp. 649—67 1, 7 pls., 3 figs. MILLER, S. A., 1889, North American geology and paleontologyI 718 pp., 1265 figs. MOORE, R. C., 1919, The Bend series of central Texas: Am. Assoc. Petroleum Geologists Bull., vol. 3, pp. 217—241. MOORE, R. C., and PLUMMER, F. B., 1922, Pennsylvanian stratigraphy of north-central Texas: Jour. Geology, vol. 30, pp. 18—42, figs. 1—4. PANDER, C. H., 1856, Monographie der fossilen Fische des silurischen Systems der russisch—baltischen Gouvernements, pp. i-x and 1—91, 8 pls., 1 65., St. Petersburg, Russia. PLUMMER, F. B., 1950, The Carboniferous rocks of the Llano region of central Texas: Texas Univ. Bull. 4329, 170 pp., 22 pls., 14 figs., 4 charts. PLUMMER, F. B., and MOORE, R. C., 1922, Stratigraphy of the Pennsylvanian formations of north—central Texas: Texas Univ. Bull. 2132, 237 pp., 27 pls., 19 figs. (Date of imprint, 1921) 1938, Zonation and correlation of the older Carboniferous rocks of the Llano uplift in central Texas (abstract): Geol. Soc. America Proc. for 1937, p. 104. PLUMMER, F. B., and SCOTT, GAYLE, 1937, Upper Paleozoic ammonites and fusulinids in Texas, part 1, Upper Paleozoic ammonites in Texas, in The geology Of Texas, vol. 3: Texas Univ. Bull. 3701, 516 pp., 41 pls., 88 figs. ROUNDY, P. V., 1926, Part 2, The micro-fauna, in Roundy, P. V., Girty, G. H., and Goldman, M. I., Mississippian formations of San Saba County, Tex.: U. S. Geol. Survey Prof. Paper 146, pp. 5—23, pls. 1—4. - STAUFFER, C. R., 1935a, Conodonts of the Glenwood beds: Geol. Soc. America Bull., vol. 46, pp. 135-168, pls. 9-12. 1935b, The conodont fauna of the Decorah shale (Ordo- vician): Jour. Paleontology, vol. 9, pp. 596— 620, pls. 71-75. STAUFFER, C. R., and PLUMMER, H, J., 1932, Texas Pennsyl- vanian conodonts and their stratigraphic relations: Texas Univ. Bull. 3201, pp. 13—58, pls. 1—4. THOMAS, L. A., 1949, Devonian-Mississippian formations of southeast Iowa: Geol. Soc. America Bull., vol. 60, no. 3, pp. 403—438, 4 pls. ULRICH, E. 0., and BASSLER, R. S., 1926, A classification of the toothlike fossils, conodonts, with descriptions of American Devonian and Mississippian species: U. S. Nat. Mus. Proc., vol. 68, art. 12, 63 pp., 11 pls., 5 figs. WELLER, J. M., and others, 1948, Correlations of the Mississip- pian formations of North America: Geol. Soc. America Bull., vol. 59, no. 2, pp. 91—196, 7 figs, 2 pls. YOUNGQUIST, WALTER, 1945, Upper Devonian conodonts from the Independence shale(?) of Iowa: J our. Paleontology, vol. 19, pp. 355—367, pls. 54—56. INDEX A Page alta, Cavuwnathua ............................................................ 77 anwlaris, Bactrornathua. . 78 arcuatua, Subbrvantodua ....................................................... 89 B Budroanazhus ................................................................. 78 , angular“. . 78 ‘ claviger _ _ 72, 78 diatom: . . 78 e1 cavata ...... 78 hamala ...... 78 inomata ......... 78 Barnett formation, age ....................................................... 69—70 collecting localities. See Localities. oonodont fauna] zones .................................................... 70-72 correlation ........... 69—70 measured sections1 .. _ ________ 73-76 barnettana, Roundya ...... 71, 72, 88, 89, table 1, pl. 16 bicuspidua. Gnathodua tawnus. .. 71, 72, 79, 80. 81, p]. 14 bidentatus, Prionhdua. _ 85 bilineata, Polygnathus. bllimatua, Gnathodus. . “.71. 72, 78, 79 71, 72, 78, 81, table 1, pl. 14 Polwnathua .......... _ 79 brassfieldensia, Trichonodella __________________________________________________ 89 ’ C carlnata, Trichonodella ....................................................... 89 Camagnathua ................................................................. 77 alta ....... .. ........ 77 criatata ................................................. 71, 72, 77, table 1, pl. 14 sp ......................................................... Centrodua' ___________________ lmeatus ................................................................... simplex ................................................................... 83,85 clarki, Liaonodimz _____________ 33 plaviger, Bactrognathus ........................................................ 72, 78 Gentcutatus ...................................... 71, 72, 77, 78, 87, table 1, pl. 15 Polygnathus ............................................. 71, 72, 77, 78, pl. 15 Cloud, P. E., Jr., and Barnes, V. E.. quoted. ............................... 70 commutatus, Gnathodus _______________________________________________________ 72, 80 Spathoomthodua. - - . ____________________ 72, so criatata, Cavusgnathus ...................................... 71, 72, 77, table 1, pl. 14 cruciformia, Staurognathua ____________________________________________________ 78 Ctenognathus sp. A ....... ._ 71, 72, 81, pl. 16 sp. B ........................................................... 71, 72, 89, pl. 14 D distarta, Badrognathua ........................................................ 78 Distribution ........................... table 1 Doliognathua. _ ____________________________________________ 78 dubio. _... ..................... , ............................... 7 8 Dryphenatus .................................................................. 78 dubia, Dolioanathus. .0. . .............................................. 78 Polmmathus ........................................................... s4, 35, 86 E edentata, ’I‘richonodetla ........................................................ 89 elegam,Prioniodua.......1"_......“....._._._._._._.___..: __________________ ~ 87 elongata, Palmatolepia. gs cmis, Hindeodella ........................................... 71, 72, 81 , table 1, pl. 16 Euprioniodina sp ............................................................. 72,78 excavate, Bactroanathm ........................................................ V 78 F Field work ................................ 1 ___________________________________ 69 fragilis, Liaonodina ................................................ 89, table 1, pl. 15 Page G Geniculatue ................................................................... 77, 78 clavicer- .. _ 71, 72, 77. 78, 87. table 1, pl. 15 girtui,Gmeh0dus_. ._.__......_......_._.. ............... 80, table 1, pl. 14 glabra, Palmtolepis. ......................................... 71, 86, pl. 15 Gnutlwdua .................... 71, 78 bilineama. _ ................................ 71, 72, 78. 81, table 1, pl. 14 commutatuo ............................................................... . 72, 80 flirty! .............. 80, table 1, pl. 14 inornatua" ............................. 71, 72, 80, table 1, pl. 14 limul/ormia. ................................................ 71 mommis ............................................................... 78 pmtuloam.. . .......................................................... 72, 79 tetanus ................................... 71, 72, 79, 80, table 1, pl. 14 teranm Mcuspidus...__......_.......-._....._.: ......... 71, 72,79, 80, 81, pl. 14 H hamata, Bactroanathua ........................................................ 78 healdi, Prioniadus. _ _ 1 71, 72, 78. pl. 15 undata ..................................................... 72, 82, table 1, pl. 16 sp. A ....................................................... 72 sp .................................................................. 72, 81, 82, 84 I Idlopriom‘adus ................................................................ 82 atrium: ......................................... 89 inclinatus, Prionlodue... ______________________ 71, 72, 78, 87', table 1, pl. 16 inomata, Bactroanathua. ............................................ 78 inomatus, Gnathoduo. _ _ .. 71, 72, 80, table 1, pl. 14 Introductionuunuu _ ................................................ 69 L laminata, Trichogrmthuc ....................................................... 89 ligo, Priom‘odus ............................................. 71, 87, 88. table 1, pl. 16 Ligonadina .............................................................. 71, 82 clarki... .............. 83 fragilis- ........................................... 8!, table 1, pl. 15 pectiuata" ........................................................ 82 roundyi. .1 71, 72, 88, table 1, pl. 15 tennis“ ............................................ 82 typa. _ ........................................ 83 sp ................................ 72 llneata, hindemiella. .......................................... 84 lineatus, Centrodua.. .......................................... 84 Lonchodus ........ -._ 71, 84, table 1, pl. 14 linguiforuia, Gnathodusn ........................................... 71 Localities, list, descriptiom. ............................................ 76-77 map showing ...... _. fig. 4 logam’, Spirifer ________________________________________________________________ 71, 73 Lonchodmas . _ _________________________________________________ / _________ 78, 83 paraclarkt 71,83, table 1, P]. 16 Lonchodus .................................................................... 83, 84 limatus ..................................................... 71,84, table 1, pl. 14 simpler _______________________________________________ 71, 72, 84, 85, table 1, pl. 14 , M , Macropolwnathus ................ - _____________________________________________ 86 Metulonchodina _ _ _ 86 sp. A .................................................... 72, 78, 85, table 1, pl. 16 sp __________________________________________________________ 72 Miller, A. K., and Youngquist, Walter, quoted. 70 missuuriensis, Priomodus ______________________________________________________ 89 moaguemis, Gnathodua ...................................................... 78 93 94 INDEX, , N - Page NMWMUWJ ------- , ----------------------------------------------------------- 7 9 Sections, stratigraphic ________________________________________________________ 73—76 0 :eparata, Trlchoanaflma _____________________________________________ . simplex, Centrodus- "Mu" Pmmo‘w" """"""""""" 38 Lonchoduc ..... ___ 71, 72,34,863 table 1, pl. 14 P Synpritmiodina. _ Palmatolepis ___________________________ 85 singular“, Prioniodus.. elongata.. ._- _ _ 86 Spajhodus ------------------------ 79 :3 mmus ___________________________________________________________________ , 21322;; ________ 7_ l;f”__tf‘_bl_°__l_’ p" :2 Spathoanathodus .............................................................. 78 paraclarki, Lonchodim.. 71,83,tab]e 1, pl. 16 commutatus'"""""""'"“"""""""“""" “““““““““““ 80 pectimua, medimu _____________ 82 Spirifer. locum ................................................................ 71,73 peracutus, Prioniodus-. _ 71, 87, 88, pl. 16 Stauroaqathus --------------------------------------------------- 78 perlobala, Palmatolepla. ___ -_ 86 cruaformia: -------------------------------------------------------- 73 Plaviodiml _____________ _ 82 striatus, Idiopnonlodus ________________________________________________________ 89 Hummer, F. B" quoted_ _ 7o cubacodua, Priomodua ......................................................... 89 Palwnathus. . ___- 86, 87 Subbryaniadus ---------------------------------------------------------- 711:: . arcua us __________________________________________________________________ 23:23:; ___-71_’_72’ 78’ Z3 roundw' .................................................. 71. 72,89,tab1e 1. pl. 1; . sp _______________ 2202f: subtilis, Hindeodella ___________________________________________________________ 81 tajfi... . 71, 86', table 1, pl. 14 ’"mm‘f’icfl' ,Tm’.‘°”"“"‘“’ ---------------------------------------------------- 9° taunt _ _____ 71, 72, 79, 81 Sunpmmwdma mnzflct ....................................................... 85 s p. , A ___________ 7], 86, pl. 15 Systematic descriptions ....................................................... 77—90 prima, Trichoonathus. ..... 90 71, 87 T 85 mm, Polygnathus...._‘._._'. .................................... 71,86, table 1, pl. 14 ________ 37 Taphro‘mathus. _ 71 ______________________ 71,72,78,‘pl. 15 tenuls,LiaOnodma 82 .............. 71, 72, 7s, 87, table 1, pl. 15 tetana,Pol1/anathus 71.72. 79, 81 _____ 71,37, 33, table 1, p1, 16 tetanus bicuspidua, Guathadua" -..- 71, 72. 79, 80. 81, pl. 14 _____________ 39 Gmuhodus 71, 72, 79,80, table 1, pl. 14 ________ as Spathodus 79,80 _______ 71,87,88, pl. 16 Trichagnathus.....-.--.----.-.. ._ 71,88, table 1, pl. 15 laminata .................................................................. 89 ________________ prima“..._._._._._____..._.__._.____._._-_________.-_...___.._..-_____-.. 90 separata ____________________ _ 89 ____________ symmetrica........--.____-___-_____-1_..____.._,__,..______ _ 90 tumida ..................................................... _ 89 Trichonodclla ______ _ 89 brassfieldensis .......................... _ 89 carinata ................................ - 89 edmtata ............ . 89 tumida, Trichoamthus .................. . 89 typa, Ligonodma .............................................................. 83 References .............................. U Round a... bafmm ____________________________ 71’ 72' 88, 89. table 1’ pl. 16 mm, Hmdeodena ............................................. 72,82, table 1. pl. 16 roundyl, Ligonodina ........................... L ............. 71, 72, 82, table 1, pl. 15 Prioniodua _________________________________________________ 71, as, table 1, pl. 15 W Subbrvantodus ___________________________________________ 71, 72, 89, table 1, pl. 14 Weller: J~ Mn and “be“! (“mad --------------------------------------------- 70 S Z scitulus, Prioniodus ___________________________________________________________ 88 Zones based on conodont occurrence .......................................... 70-72 PLATES 14—16 FIGURES 1, 2. 3—6. 9—11. 12—14. 15—21. 22—24. 25-29. PLATE 14 Barnett formation; upper conodont faunal zone [Figures are 30 times natural size] Lonchodus lineatus (Pander) (pp. 84, 85). 1, Lateral view of conodont fragment, hypotype, U.S.N.M. 115076 [=L0nchodus? lineatus (Pander). Roundy, U.S.G.S. Prof. Paper 146, pl. 3, fig. 8; U.S.G.S. Carb. cat. 4031a], collection 2613c. 2, Lateral View of conodont fragment, hypotype, U.S.N.M. 115077 [=Lonchodus? lineatus (Pander). Roundy, U.S.G.S. Prof. Paper 146, pl. 3, fig. 7; U.S.G.S. Garb. cat. 4030a], collection 2609. Subbryantodus roundyi Hass, n. sp. (p. 89). Lateral views of the inner side. 3, Paratype, U.S.N.M. 115078, collection 9309. 4, Holotype, U.S.N.M. 115079, collection 9310. 5, Paratype, U.S.N.M. 115080 [= Ctenognathus sp. B Roundy, U.S.G.S. Prof. Paper 146, pl. 2, fig. 4; U.S.G.S. Carb. cat. 4032a], collection 2609. 6, Paratype, U.S.N.M. 115081 [=Ctenognathus sp. B Roundy, U.S.G.S. Prof. Paper 146, pl. 2, fig. 5; U.S.G.S. Carb. cat. 4033a], collection 2613h. . Lonchodus simplex (Pander) (p. 85). Lateral View of conodont fragment, hypotype, U.S.N.M. 115082 [=Lonchodus simplex (Pander). Roundy, U.S.G.S. Prof. Paper 146, pl. 3, fig. 5; U.S.G.S. Carb. cat 4026a], collection 2609. . Polygnathus tafli Roundy (pp. 86, 87). Oral View of a fragmentary specimen which is not considered to be a part of the Barnett fauna. Holotype, U.S.N.M. 115083 [=U.S.G.S. Prof. Paper 146, pl. 3, figs. 11a, 11b; U.S.G.S. Carb. cat. 4020a], collection 7016 (green). Gnathodus inornatus Hass, n. sp. (p. 80). 9, Oral View, holotype, U.S.N.M. 115084, collection 9309. 10, Aboral view, paratype, U.S.N.M. 115085, collection 9309. 11, Lateral view, paratype, U.S.N.M. 115086, collection 9309. Cavusgnathus cristata Branson and Mehl (p. 77). 12, Oral View, hypotype, U.S.N.M. 115087, collection 9311. 13, Oral View, hypotype, U.S.N.M. 115088, collection 9311. 14, Lateral View of inner side, hypotype, U.S.N.M. 115089, collection 9311. Gnathodus texanus Roundy (pp. 80, 81). 15, Oral View, holotype, U.S.N.M. 115090 [=U.S.G.S. Prof. Paper 146, pl. 2, figs. 8a, 8b; U.S.G.S. Carb. cat. 4018a], collection 2688. 16, Oral View, paratype, U.S.N.M. 115091 [=Gnathodus tetanus var. bicuspidus Roundy. U.S.G.S. Prof. Paper 146, pl. 2, figs. 9a, 9b; U.S.G.S. Carb. cat. 4019a], collection 2613c. 17, Oral View, ,paratype, U.S.N.M. 115092 [=U.S.G.S. Prof. Paper 146, pl. 2, figs. 7a, 7b; U.S.G.S. Carb. cat. 4017a], collection 2609. 18, Aboral View, hypotype, U.S.N.M. 115093, collection 9310. 19, Oral View, hypotype, U.S.N.M. 115094, collection 9310. 20, Oral View, hypotype, U.S.N.M. 115095, collection 9310. 21, Lateral view of outer side, hypotype, U.S.N.M. 115096, collection 9310. Gnathodus girtyi Hass, n. Sp. (1). 80). 22, Oral view, holotype, U.S.N.M. 115097, collection 9310. 23, Lateral View of outer side, paratype, U.S.N.M. 115098, collection 9310. 24, Oral View, paratype, U.S.N.M. 115099, collection 9310. Gnathodus bilineatus (Roundy) (pp. 78—80). Oral views illustrating specific variation and the development of characteristics during ontogeny. 25, Hypotype, U.S.N.M. 115100, collection 9309. 26, Holotype, U.S.N.M. 115101 [=P0lygnathus bilineata Roundy, U.S.G.S. Prof. Paper 146, pl. 3, figs. 10a—c; U.S.G.S. Carb. cat. 4021a], collection 2609. 27, Lateral View of outer side, hypotype, U.S.N.M. 115102, collection 9309. 28, Hypotype, U.S.N.M. 115103 [=Polygnathus lemma Roundy, U.S.G.S. Prof. Paper 146, pl. 3, figs. 13a, 13b; U.S.G.S. Carb. cat. 4013a], collection 2618. 29, Hypotype, U.S.N.M. 115104, collection 9309. PROFESSIONAL PAPER 243 PLATE l4 GEOLOGICAL SURVEY .1 CONODONTS, BARNETT FORMATION (MISSISSIPPIAN) GEOLOGICAL SURVEY PROFESSIONAL PAPER 243 PLATE l5 CONODONTS, BARNETT FORMATION (MISSISSIPPIAN) FIGURE 1. 2, 3. 10-19. PLATE 15 Barnett formation; upper conodont faunal zone [Figures are 30 times natural size] Liganodina fragilis Hass, n. sp. (p. 82). Lateral View of inner side, holotype, U.S.N.M. 115057, collection 9312.‘ Prioniodus roundyi Hass, n. sp. (p. 88). Lateral views of the inner side. 2, Holotype, U.S.N.M. 115058, collection 9310. 3, Paratype, U.S.N.M. 115059 [=Pm'om‘odus sp. B Roundy, U.S.G.S. Prof. Paper 146, pl. 4, fig. 10; U.S.G.S. Carb. cat. 4024a], collection 2609. ‘ . Palmatolepis glabm Ulrich and Bassler (p. 86). Oral View of a fragmentary specimen regarded as reworked into the Barnett fauna. Hypotype, U.S.N.M. 115060 [=Polygnathus sp. A Roundy, U.S.G.S. Prof. Paper 146, pl. 3, figs. 12a, 12b; U.S.G.S. Carb. cat. 4014a], collection 2609. . Ligonodina roundyi Hass, n. sp. (pp. 82, 83). 5, Lateral View of outer side of immature fragmentary specimen, paratype, U.S.N.M. 115061 [=Priom'odus sp. A Roundy, U.S.G.S. Prof. Paper 146, pl. 4, fig. 9; U.S.G.S. Carb. cat. 4035a], collection 2609. 6, Lateral View of inner side of immature fragmentary specimen, paratype, U.S.N.M. 115062 [=Priom‘odus sp. C Roundy, U.S.G.S. Prof. Paper 146, pl. 4, fig. 11; U.S.G.S. Carb. cat. 4025a], collection 2609. 7, Lateral View of outer side of main cusp, paratype, U.S.N.M. 115063, collection 9312. 8, Lateral view of inner side of main cusp, paratype, U.S.N.M. 115064, collection 9312. G 9, Vliew oflposterigi sideio§ main'rcéusysémd anticusp, holotype, U.S.N.M. 115065, collection 9312. em'cu atus c (wiger oun y pp. . 10,fi Oral View}, éuéogypce, E. S. N. M. 11150166 t[=1;oéggnathus? claviger Roundy, U.S.G.S. Prof. Paper 146, pl. 4, gs. la—c; . . . . ar .cat. 4015a, co co ion . ~ 11 View of outer side of main cusp, hypoty e, U.S.N.M. 115067 [=Pm'0m'odus sp. D Roundy, U. S. G. S. Prof. , Paper 146, pl. 4, figs. 13a, 13b; U.S.G.S. arb. cat. 4036a], collection 2609. 12, Lateral view of inner side of distal end of posterior bar paratype, U.S.N.M. 115068 [=Polygnathus? claviger Roundy, U_.S.G.S, Prof. .Paper 146, pl. 4, figs. 2a, 2b; U. .G.S. Carb. cat. 4016a], collection 2613e. ‘ 13, Lateral VleW of_outer s1de, hypotype, U.S.N.M. 115069,.collect10n 9310. 1:: W 0: .3. g-s-m 323:9, wrote 22;?- , lewo inner 51 e, ypo ype . . . . ,co ec ion . 16, View of inner side, hypotype, U.S.N.M. 115072, collection 9312. 17 View of outer side of main cusp, hypotype, U.S.N.M. 115073 [=Priom‘odus healdi Roundy, U.S.G.S. Prof. Paper 146, pl. 4, figs. 5a, 5b; U.S.G.S. Carb. cat. 4034a], collection 2688. 18, Oral view of specimen lacking distal end of anterior bar, hypotype, U.S.N.M. 115074, collection 9313.. 19, Oral view of specimen lacking distal end of posterior bar, hypotype, U.S.N.M. 115075, collection 9313. Figures 1—3. 8,9. 10—14. 15, 16. 17, 18. 19—21. PLATE 16 Barnett formation; upper conodont faunal zone [Figures are 30 times natural size] Prioniodus ligo Hass, n. sp. (pp. 87, 88). 1, Lateral view of inner side, holotype, U.S.N.M. 115172, collection 9317. 2, Lateral view of outer side, paratype, U.S.N.M. 115173 [=Priom'odus peracutus Hinde. Roundy, U. S. G. S. Prof. Paper 146, pl. 4, fig. 8, U. S. G. S. Carb. cat. 4022a], collection 2609. 3, Lateral View of outer side, paratype, U.S.N.M. 115174 [=Priom'odus peracutus Hinde. Roundy, U. S. G. S. Prof. Paper 146, pl. 4, fig. 7; U. S. G. S. Carb. cat. 4023a], collection 2613g. . Prioniodus singularis Hass, n. sp. (p. 88). 5-7. Lateral View of inner side, holotype, U.S.N.M. 115175, collection 9309. Hindeodella undata Branson and Mehl (p. 82). 5, Lateral View of inner side, hypotype, U.S.N.M. 115176, collection 9312. 6, Lateral View of bar fragment, hypotype, U.S.N.M. 115177, collection 9312. 7, Lateral View of inner side, hypotype, U.S.N.M. 115178, collection 9312. Roundya barnettana Hass, n. sp. (p. 89). ' 8, Posterior view of anterior arch, holotype, U.S.N.M. 115179, collection 9310. 9, Lateral View, paratype, U.S.N.M. 115180, collection 9312. Priom'odus inclinatus Hass, n. sp. (p. 87). 10, Aboral View of main cusp, paratype, U.S.N.M. 115181, collection 9310. 11, Lateral view of inner side, holotype, U.S.N.M. 115182 collection 9310. 12, Lateral View of inner side of main cusp, paratype, U. .N.M. 115183 [=Prz'om'odus sp. D Roundy, U. S. G. S. Prof. Paper 146, pl. 4, fig. 12; U. S. G. S. Carb. cat. 4037a], collection 2613c. ' ' 13, Lateral View of outer side, paratype, U.S.N.M. 115184, collection 9312. 14, Lateral View of outer side, paratype, U.S.N.M. 115185, collection 9312. Lonchodina paraclarki Hass, n. sp. (p. 83). 15, Lateral view of outer side, holotype, U.S.N.M. 115186, collection 9309. 16, Lateral view of outer side, paratype, U.S.N.M. 115187, collection 9312. Metalonchodina, sp. A (p. 85). 17, Lateral View of inner side, figured specimen, U.S.N.M. 115188, collection 9313. 18, Lateral view of inner side, figured specimen, U.S.N.M. 115189, collection 9310. Hindeodella ensis Hass, n. sp. (pp. 81, 82). Lateral views of inner side. 19, Paratype, U.S.N.M. 115190 [=C’tenognathus sp. A Roundy, U. S. G. S. Prof. Paper 146, pl. 2, fig. 3; U. S. G. S. Carb. cat. 4029a], collection 2609. 20, Holotype, U.S.N.M. 115191, collection 9309. 21, Paratype, U.S.N.M. 115192, collection 9312. O PROFESSIONAL PAPER 243 PLATE 16 G BIOLOGICAL SURVEY . 21 CONODONTS, BARNETT FORMATION (MISSISSIPPIAN) w. flzm {WE’- . Auditory Region in North American Fossil F elidae: Its Significance in Phylogeny GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-G GEOLOGICAL SCIENCES LIBRARY Auditory chionin North American Fossil Felidac: I Its Significance in Phylogeny By JEAN HOUGH SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 95—115 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243—G Detailed deseriptiom and illustrations of t/ze ‘ ear region in somefosyi/ and recem‘ geflera, cma’ a proposed reviyiofl ofmperfamiiy classification oftfle Carnivore UNITED STATES GOVERNMENT PRINTING OEFICE, WASHINGTON : 1953 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. — Price 20 cents (paper cover) CONTENTS Abstract ______________________________________ I. _____ Introduction _______________________________________ Acknowledgments ___________________________________ General characters of the auditory region in Oligocene Felidae __________________________________________ Auditory bulla _________________________________ Basicranial foramina ____________________________ Generic descriptions _________________________________ Subfamily Machaerodontinae _____________________ Hoplophoneus ______________________________ General characters ______________________ Auditory bulla- _ _ _ - ~_ ___________________ Basicranial foramina ____________________ Eusmilis ___________________________________ General characters ______________________ Middle and inner ear structure ___________ Basicranial foramina ____________________ Pliocene machaerodonts _____________________ Smilodon __________________________________ General characters ______________________ Internal structure of the auditory bulla___- Structure of the middle and inner ear- _ _V_ - Basicranial foramina __________________ '_ - Page 95 95 97 97 97 99 101 102 102 102 Generic descriptions—Continued Subfamily N imravinae- - _ -' ______________________ Dim'ctis (Oligocene species) __________________ External characters _____________________ Internal structure of the bulla and middle ear- Basicranial foramina ____________________ Dim'ctis cyclops Cope (John Day species) ______ Nimravus __________________________________ Subfamily Pseudaelurinae ________________________ American genera ____________________________ Asiatic and European genera _________________ Summary and conclusions ________________________ Homology of basicranial features of the Feloidea ________ Septum bullae __________________________________ Form and position of the septum _____________ Mode of development of the bulla ____________ Basicranial foramina ____________________________ Summary and conclusions ________________________ Evolution of the intracranial circulation _______ Evolution of the auditory bulla _______________ Proposed taxonomic changes _________________ Summary of superfamilies and families ________________ Selected references __________________________________ ILLUSTRATIONS FIGURE 5. Hoplophoneus primaevus oreodontis- _ _ _ _ _ - .- _ '1’ 6. Smilodon californicus _________ p _____________ 7. Smilodon califomicus _____________________ ._ 8. Dinictis felina ___________________ 1 ___________ 9. Dinictis cyclops__ _ _ _ _ -., _. , __ Page '98 100 100 104 105 FIGURE 10. Viverricula ind. rasse_,_, _,__1,.. H1, "7 11. Felis catus ________________________________ 12. Cam's dingo__,._..___1..__ , “”7 ,7 M- 13. Vulpes velar-“ - at, , III Page 103 103 103 103 103 105 106 106 106 106 106 107 ' 107 107 109 110 112 112 112 113 113 115 Page 108 108 110 111 AUDITORY REGION IN NORTH AMERICAN FOSSIL FELIDAE: ITS SIGNIFICANCE IN PHYLOGENY By JEAN HOUGH ABSTRACT The auditory region of. the North American fossil Felidae is described in detail. In the Oligocene Felidae the characters of this region, especially the foramina associated with the veins and arteries of the head, are like those of the modern Canidae rather than the Felidae. On the contrary, all of the middle Miocene (post-John Day) and later genera have typical felid characters in this part of. the skull. This has profound sig- nificance for the phylogeny and major taxonomy of the family. If any of the species of Oligocene felids are ancestral to the modern forms, an evolution of both the venous and arterial system of the head as well as the auditory bulla must have taken place. This is quite possible, for not only is there theoretical sup- port for it in the ontogeny of modern genera, but there are species that have characters linking the Paleofelides to the Neofelides. Nevertheless, postulating such an evolution is a radical step as it throws doubt upon the validity of the current superfamial classification of the Carnivora. This arrangement is based pri- marily on the homology of the two-chambered bulla, and the presence or absence of the postglenoid foramen. If, as this paper attempts to show, these structures are not homologous, but have evolved independently in the Viverridae and Felidae (and in other families), the categories Aeluroidea and Arctoidea of Flower (Feloidea and Canoidea of Simpson) have no phylo- genetic significance, but are at best convenient divisions appli- cable to modern genera only. INTRODUCTION The threefold division of the Carnivora into Aeluroi- dea, Cynoidea and Arctoidea was based by Flower (1869) primarily on the characters of the auditory re— gion, especially the presence or absence of a septum di- viding the bulla into two chambers, and the arrange- ment of the basicranial foramina. In these features, the Aeluroidea (Viverridae, Felidae,I—Iyaenidae) repre- sent one extreme, the typical arctoid Carnivora (Mus- telidae,Procyonidae,Ursidae) another. The Cynoidea (Canidae) Flower thought intermediate between the two. In the Aeluroidea the interior of the bulla is di- vided into two chambers by a septum which completely closes ofl’ the chambers except for a small opening just below the fenestra cochleae; the postglenoid foramen is reduced or absent, the condyloid foramen concealed by the foramen lacerum posterius, the carotid canal re- duced to a vestige and the posterior carotid foramen (where present at all) very inconspicuously placed in a common fossa with the posterior lacerate foramen. The ’ Arctoidea, on the other hand, have a simple, one-cham- bered bulla, a large postglenoid foramen, a large condy— loid foramen quite distinct from the foramen lacerum posterius, a well-developed bony canal for the carotid artery and a large posterior carotid, foramen also dis- tinct from the posterior lacerate foramen. The Cynoi- dea have some features of each group. There is a par- tial septum, the postglenoid foramen is moderately large, the 'condyloid foramen is smaller than in the Arctoidea and the carotid canal less conspicuously de- veloped. The posterior carotid foramen is a narrow slit opening into the common fossa with the foramen lacerum posterius. These characters were probably considered by Flower, and certainly by Turner (1848) who originated the idea, as no more than morphological correspond— ences the use of which gave a more natural classification (seam Dobzansky, 1941, p. 363) than the use of adap- tive characters of the limbs and teeth. Mivart, how~ ever, in a series of papers (1882, 1885, 1890) elaborated on the idea extensively, giving it an archetypal signifi- cance by compiling long lists of features in the soft parts and skeleton linked, as he thought, with the key characters of the basicranium. With the rise of' the evolutionary theory, this archetypal concept of homol- ogy gave way in turn to a phylogenetic one. Homol- ogy indicated common ancestry, proof of which was to be sought first in ontogeny, and later, as the fossil record became better known, in paleontological history. The first result of this shift in zoological theory was the reduction of F lower’s threefold classification to a twofold one. Flower had considered the partial sep- tum found in many canids, and especially well devel- oped in Uanis jubatus homologous with the septum bullae of Felix, at least in the morphological sense. (It has the same position and where the bullae is well in- flated appears to be an intermediate stage in the evolu- tion of the typical felid septum.) Winge’s studies (1895) seem to show that the septum of Cams was, in fact, homologous in mode of origin (not position) with the septae and rafters that radiate from the crista 95 96 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 tympani across the walls of the bulla in some mustelids. These are ,ossified from folds of the mucuous lining. In spite of the fact that this homology was disputed by Van Kampen (1905) who denied that the septum in Cam's originated from mucous folds and considered it rather a part of the original wall become concave by bone apposition on the outer side and simultaneous re- sorption on the inner side, Winge’s classification con- tinued to be universally accepted for over half a cen— tury. This Was in part due, however, to support given to the idea of'the homology of the basicranial characters of the Cynoidea and Arctoidea by certain phylogenetic theories of Matthew (Wortman and Matthew, 1899). These theories, which derived the Procyonidae and Ursidae from Miocene canids, were based almost wholly on dentition and tended to make the Canidae the central stock of the arctoid Car- nivora. Their influence was so great that except for a few minor shifts of certain problematical families and the substitution of the names Canoidea and Feloidea by Simpson, (1945), for the Arctoidea and Aeluroidea of Flower the resulting division ofthe Car- nivora into two superfamilies (and the phylogeny de- rived from this) has, to the writer’s knowledge, not been challenged until recently. The increase in knowledge of the fossil carnivora, however, has brought many new facts of morphology and phylogeny to light. Some of these were presented by the writer in an earlier paper (Hough, 1948), in which it was shown that the derivation of the Procyo— nidae and Ursidae from Miocene canids is untenable when characters other than those of the dentition are ' taken into consideration. The work of Scott and J ep- sen (1937), Jepsen (1933, 1941) on the fossil Felidae has emphasized the antiquity of this family, and its separation from the Viverridae. These facts, together with much unpublished data known to specialists in the field, tend to cast doubt on the validity of the super— family arrangement of the Carnivora and to pose many taxonomic problems for which to date no consistent so- lution has been offered. In fact, the general taxonomy of the order has blundered along in a curious kind of compromise by which one set of criteria are used for de- termining the systematicposition of recent forms and quite another that of the fossil genera. The recent C'anidae, for example, are included in the Canoidea because of the supposed homology of the septum pres- ‘ ent in some canids with that of such of the arctoid Car— nivora as have septae, and because of a hypothetical relationship of fossil forms based on dentition. Daphoenus, which has a demi-bulla virtually identical with that of both the modern N andz'm'a and the fossil Paleoprionodon contemporary with Daphoenus, is also included in the Canoidea but on the basis, presumably, of the dentition, or of an alleged canid ancestry. Paleopm'onodon and Paradaphoenus, whose basi- cranial characters are almost exactly alike, are placed in different superfamilies, one in the Feloidea and the other in the Canoidea presumably on the basis of den- tition although the dental characters of Paleopm‘o’no- don differ frOm those of Paradaphoemts in the same way that those of Poz’am differ from Oivetictis—mod— ern viverrines included by Gregory (1939) in the same subfamily. The basicranial foramina of the fossil Felidae have long been known to be canoid (Scott and J epsen, 1937 ; J epsen, 1933) but, although these features are considered of paramount importance in the classi- fication of Modern carn1v01 es, they have been entirely ignored in the superfamily allocation of the fossil Felidae. The writer feels that the inconsistencies are, in fact, so great that a paleontologist from Mars, with no inherited prejudices based on the magic of names would be hard put to understand our classification at all. This confusion in taxonomy has arisen, of course, from a confusion as to the definition and significance of homology. As applied to modern carnivores, the concept, in practical usage at any rate, has largely an archetypal significance. Applied to fossil forms, homologies are used as a means of tracing phylogenies. The result, naturally, is extremely illogical. Zanger] (1949), impressed by some of these inconsistencies and the circular reasoning which is both a cause and a result, has argued recently for a return to a purely archetypal definition of homology. This, however, 1s clearly impossible under current evolutionary theory, the soundness of which seems, at least in the present state of knowledge, firmly established. Attempting to turn back the clock, zoologically speaking, would lead only to further confusion. A phylogenetic definition of homology is the only theoretically sound one. In any case, the dilemma is more apparent than real. The two concepts of homology, properly interpreted, sup- port one another. True correspondence in structure can only be the result of similar ontogenetic develop— ment and this in turn depends ultimately on a common phylogenetic origin. General correspondence of struc— ture, and even in some instances detailed similarities can, of course, be the result of parallelism and con- vergence. (For a full discussion of this see Haas and Simpson, 1946.) However, the writer believes that in mammals, at least, these processes can be distin- guished if all lines of evidence are properly evaluated. It IS the duty of a good phylogenicist to do this, however difficult the task may be. AUDITORY REGION In fossil F 'elidae the difficulty is particularly great because of the large amount of parallelism and-con— vergence, not only in the dentition, as is generally rec- ognized but, as will be shown in this paper, in the basicranial structure as well. The studies here pre- sented are an attempt to examine as thoroughly as possible the facts of the supposed homologies on which the major taxonomy of the Feloidea is based and to propose a theory of phylogeny supported by, or at least not inconsistent with, these facts. ACKNOWLEDGMENTS Some of the data on which the study is based were gathered from museums other than the U. S. National Museum under a grant from the Geological Society of America prior to the writer’s employment with the U. S. Geological Survey. The writer wishes to thank the council of the Geological Society of America and the staffs of the various museums in which this preliminary work was done, for their valuable cooperation. GENERAL CHARACTERS OF THE AUDITORY REGION IN FOSSIL FELIDS AUDITORY BULLA The structure of the bulla in the Oligocene Felidae is difficult to interpret. No known specimen has a complete bulla, and many have no remnants of it pre- served. Some skulls, especially those more recently collected and carefully prepared, have a considerable portion remaining—in most specimens the antero- lateral wall, including the auditory meatus and the crista tympani. A few have traces of the posterior and medial walls. Moreover, a careful examination of the bones in contact with the roof of the bulla—the basioccipital, basisphenoid, exoccipital and petrosalm show unmistakable impressions of a bulla even in skulls where no remnant now remains in place. Piviteau has described this same condition in the skulls of the European species, Eusmz’lz's bidentatus (Piviteau, 1931, p. 31, Pl. VI, fig. 1). The anterolateral portions of the bulla, which are present in many specimens, have been interpreted as an anterior (tympanic) chamber similar to that of the living Viverridae or Felidae—interpretations differ as to which. Plausible as. this idea. is (and consistent with the accepted taxonomy of the Felidae) it is almost certainly not correct. Aside from the impressions on the roofing bones, mentioned above, there is evidence in the remnants of the bulla itself that that structure was complete, fully ossified and similar in shape and size to that of the Canidae. 97 IN FOSSIL FELIDAE Remnants of the bulla that remain intact in speci— mens of Hoplophoneus and Dinictis from the White River formation are not the same in size or shape in any two skulls, or even on both sides of the same skull. The edges are irregular and jagged. They are, there- fore, quite unlike the' regular, smoothly margined, horse-shoe shaped demi-bulla of such fossil forms as Paleopm’onodon and prhoenus, or the modern viverrid Nandim’a. Moreover, a demi-bulla, in those forms in which it occurs, lies at a very low angle and covers only the antero-lateral portion of the auditory region. It does not touch the basisphenoid. The margins, which are incurved, are in contact with the promontorium except directly ventral to the fenestra cochleae. In HopZOphoneus and Dim'otz's, on the other hand, the circle of bone around the auditory meatus arches around the middle ear structures. It may be in contact with the basisphenoid by a broad strip of bone, if that much of the bulla is present, but it is never in contact at any point with the promontorium. It seems to cor- respond very closely to a portion of the antero-lateral wall of the normal one-chambered bulla of the Canidae. Examination of a number of miscellaneous dog and wolf skulls that were collected after being exposed to -weathering shows that the bulla is broken in nearly all such specimens. The portions remaining are ex— actly those found in the saber tooth' carnivores—the anterior wall where it is re-enforced by its juncture with the postglenoid process, the basispenoid, the crista tympani and in some cases the medial and pos~ terior walls. The incomplete state of the bullae, there- fore, in the fossil specimens in question, can be almost certainly attributed to the conditions of fossilization, that is, to exposure to weathering for a considerable length of time before burial, followed by rapid en- tombment under a heavy load of sediment. These are exactly the conditions known to exist in a flood-plain type of depOsition, such as that of the White River formation. _\ The portions of the bulla could, of course, represent a ,part of the lateral wall of a two chambered bulla the anterior chamber of Which was globular, as in the domestic cat. Opposed to this is the contact with the basisphenoid (which never occurs in the Felidae), and the absence of any trace of a septum bullae. This septum is an extremely strong structure. Attempts to break the bulla of a cat or viverrine will easily prove that this is so. Moreover, a complete septum like that of the Felidae leaves a strong impression-on the periotic, as can be ascertained by examination of modern speci- mens, and no such imprint is present even in skulls Whose preservation is almost perfect. It seems vir- tually impossible therefore, that a septum bullae 98 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 KINEA: , /\j‘* K '1‘ . \{J \ \ / 1) 1/. .L/ i l/ .lr‘ / ,ri .../ FIGURE 5.—Hoplophoneus primaevus oreodontia Cope, Princeton Museum 10515, ‘1.. “ .I/ I a. '\ ./"""~~.. /“ \ ‘____,_-.—-" '3-/ X135. AUDITORY REGION corresponding to that of the modern LFelidae in form and position was present in the Oligocene genera. BASICRANIAL FORAMINA The basicranial foramina of the Oligocene Felidae are as anomalous as the structure of the auditory region. They are distinctly not feloid—(Scott and J epsen, 1937, Piviteau, 1931, and others) in number or position. There is an alisphenoid canal, and‘a large postglenoid foramen. ‘The condyloid foramen is large and well separated from the foramen lacerum posterius. ‘The carotid canal is well defined and terminates either in a space between the alisphenoid and promontorium or a large foramen lacerum medium. The posterior carotid foramen is behind the foramen lacerum posterius and well separated from it. These characters are all canoid and point to a venous and arterial system of the head almost at the opposite extreme from that of the modern Felidae. These characters as well as those of the bulla will be considered in more detail in'the following descriptions. GENERIC DESCRIPTIONS SUBFAMILY MACHAERODONTINAE HOPLOI’HONEUS GENERAL CHARACTERS The space occupied by the auditory cavity 'is narrow. (See fig. 5.) This is due, in part, to the narrowness of the basicranium itself, and in part to the enormous de- ' velopment of the mastoid processes. These form short broad columns extending forward and downward well below the plane of the basicranium. The width is so great that the medial margin is on a line with the inner margin of the glenoid fossa. Comparison with Oar/Ibis and Felis (where the mastoid hardly appears on the under surface of the skull) reveals that the space for the promontorium and structures of the middle ear is very restricted. The promontorium is large and rounded, but the depth of the cavity makes it appear buried in the basicranium. It is in fact, somewhat deeper below the level of the basioccipital than in mod- ern carnivores, or in the contemporary Dim'ctz's. The paroccipital process projects backward from the base of the mastoid and forms a distinct leaflike process. The size of the process, and its distinction from the mastoid, vary from individual to individual in the species from the Brule formation. In all known specimens from the Chadron formation it is well de- veloped and similar in shape and size to that of the contemporary daphoenids. AUDITORY BULLA Because the auditory cavity is so narrow, the bulla is almost triangular. This was determined by care— 229929—53——2 IN FOSSIL FELIDAE 99 ful preparation by G. L. J epsen of the type specimen of H. oreodmztis, Princeton Museum 10515 (fig. 5) which disclosed a considerable portion of the bulla including the rim around the external auditory meatus, and the anterior and medial wall broken off level with the basi— occipital. This wall tapers almost to a point antero- medially and broadens posteriorly. The medial wall is curved and moderately inflated but the floor is flat- tened giving a pill box shape. The lateral wall is in reality lateromedial so that the meatus faces obliquely forward, directly into the base of the postglenoid process. The mastoid and post— glenoid processes together form a long passageway, open ventrally, through which a cartilaginous tuba auditiva undoubtedly passed. The connection between the exterior of the skull and the sound producing ap- paratus thus follows a very roundabout route. The resonating chamber also is extremely small and with no extension into the mastoid or paroccipital as in recent carnivores such as Taxidea or Ursus which have a small, flattened bulla. THE BASICRANIAL FORAMINA There is a long alisphenoid canal terminating in a foramen rotundum situated at one end of a common fossa with the foramen ovale. This relationship is precisely that of Cam's except that, due to the relative shortness of the cranial portion of the skull in Hop- Zophoneus the fossa extends medlolaterally parallel to the base of the postglenoid fossa rather than antero- posteriorly as in C’tmis. The postglenoid foramen is large. The posterior carotid foramen and the foramen lacerum posterfus are separate but they are in the same relative position as in the Canidae and may have been enclosed in a common fossa. The condyloid foramen is in the same position as in Cam's, but is larger. " E USMILIS GENERAL CHARACTERS The U. S. National Museum specimens of this genus have no trace of an auditory bulla. The general aspect of the auditory region is like that of Hoplophonem, differing only in the enormous size of the mastoid process. In older individuals this process reaches the proportions of that of Smilodon, but the difference from Hoplophoneus is more than a difference in size. The mastoid is falciform with a flattened posterior surface inclined obliquely forward. The exoccipital is flat- tened against the dorsal half of this surface and makes a sutural contact with it. There is no distinct paroc- cipital process. The appearance of the hinder part of -the basicranial region resembles that of the bears, Hemicyon, the walrus, and the South American saber— 100 tooth marsupial T hylacosmz’lis, and strongly suggests that this exaggerated development of the mastoid audi— tory bulla is determined both by the size of the head and the canine teeth. In a specimen at the South Dakota School of Mines (2815), are remnants of a bulla, including the antero— lateral wall, the crista tympani and the external audi- tory meatus. The last is a short tube Whose sides are made up of the base of the postglenoid process ante- riorly, and of the mastoid posteriorly. A flattened pro- j ection of the tympanic bridges the space between these two processes and forms the floor. The very large crista tympani is projected far into the auditory cavity. A very peculiar sort of septum is formed by what ap- pears to be an extension of the base of the postglenoid process continuous with the roof of the meatus. The structures of the middle ear lie above this septum. The condition is somewhat similar to that found in Amphi— cyon, and also resembles Smilodon, where the bulla is divided into upper and lower chambers. MIDDLE A1115 INNER EAR STRUCTURE The promontorium is large and round, and situated almost in the center of the auditory cavity. The lateral and posterior surfaces are almost vertical. The fenestra cochleae lies about midway along the external face. The fenestra vestibuli is in the usual position just opposite the meatus, slightly,anterior of the anterior margin of the mastoid process. Just above this opening is the minute aperture of the facial canal. The length and position of the external part of this canal is deter— mined by the peculiar conformation of the mastoid. A deep' groove extends from the base of this process to its tip. It is parallel to the anterior margin of the process and separated from it by only a thin ridge of bone. Apparently, the facial. nerve and accompanying blood vessels leaving the apertura canalis facialis passed under the spur of bone from the base of the mastoid and from there followed along the groove to the tip of the process. This course does not differ in its position in relation to the mastoid from that of other carnivores but appears to do so because of the size and forward inclination of the mastoid process. , The carotid canal is clearly marked by a groove in the basioccipital extending anteriorly about to the midpoint of the medial margin of the promontorium. Apparently the internal carotid artery entered the cra- nium at that point. BASICRANIAL FORAMINA The basicranial foramina. are essentially the same in number and size as those of Hoplophoneus. There is an alisphenoid canal. The foramen ovale and foramen rotundum occupy a large fossa lying obliquely along SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 the ridge leading to the base of the postglenoid peduncle. There is a large postglenoid foramen. The posterior carotid foramen is large and lies very far back. It is separate from the foramen lacerum pos- terius. The condyloid foramen is also separate and very large. PLIOCENE MACHAERODONTS Two specimens from the Ash Hollow formation of Nebraska (one of which is in the Nebraska State Mu- seum and will be described in detail shortly by C. B. Schultz, the other in the Frick collection and also to be the. subject of a detailed paper some time in the future), illustrate in an interesting way the further evolution of the auditory region in the Eusmiloid group. The specimens consist of two very complete and well- preserved skulls and lower jaws with some associated skeletal material. They are clearly machairodonts but of a line divergent from the typical Smilodovn of the Rancho la Brea tar pits. The dentition is of the hop- lophonoid type with most of the characteristic features developed to a much greater degree than in Smilodon. As the writer pointed out in an earlier paper (Hough, 1950), weakness of the lower jaw in the latter seems to be a degenerate feature. These specimens not only have proportionally more alongate and recurved sabers but also strongly developed ,flanges to the lower jaw with flaring lobate margins which closely resemble those of the marsupial Thylacosmilis. The reduction of the premolars and the enlargement of the carnassial has proceeded to such an extent that P4 and M1 are the only functional cheek teeth. They extend along the entire margin of both jaws and have the back- ward inclination characteristic of the hoplophoneid and eusmiloid group. In youth the high crowns are trilobate and trenchant. Even in old age they remain efficient shearing instruments because the occlusal re— lations are such that the wear is oblique (almost a 45 degree angle, in fact), and the crowns may be worn to the gums on one margin while retaining a sharp cut- ting edge on the other. As would be expected, the mastoid processes are strongly developed, almost covering the entire auditory region. The tympanic bulla is represented by only a small swelling on the extreme medial portion of the auditory cavity. This cavity is therefore largely exca- vated in the mastoid, the hypotympanic sinus extending far into the mastoid process as in many modern muste— lines. The condition parallels that of Smilodon, to be described in detail later, but differs enough to emphasize the divergence of the lines. of descent. (In the writer’s opinion there were many lines of descent AUDITORY REGION IN FOSSIL FELIDAE from the widespread hoplophoneid population of the early Oligocene.) The smaller skull, which is also younger geologically as it comes from the middle level of the Ash Hollow formation, has a shorter upper canine with less curva- ture and a moderately developed flange to the lower jaw. Morris Skinner, who collected the specimen, rec- FIGURE 6.—Smilod0n californicus Merriam, Chicago Natural History Museum 12409 ; ventral view of auditory bulla, x 1. Anterior at top, median side at right. 101 SM I L ODON GENERAL CHARACTERS The auditory region of the well-known Pleistocene saber tooth from the Rancho la Brea Tar pits has been fully described by Merriam and Stock. The basic structure is the same as in H oplophoneus, but this sim- ilarity is masked by the enormous development of the FIGURE 7.——Smilodon call/’ornicus Merriam. Chicago Natural History Museum 12563: section through auditory region to show horizontal septum, x 1. Anterior at top, median side at right. Symbols used on figures (10 auditory ossicle fem fenestra rotundum pp paroccipital process I) bulla, remnant flm foramen lacerum medius p promontorium ce cartilaginous entotympanic flp foramen lacerum posterius rs radiating septae eam external auditory meatus fr foramen rotundum 5 major septum eb entotympanic part of bulla fs stylomastoid foramen lb tympanic bulla . e0 exoccipital gcc groove for carotid canal tm remnant of inbent margin of fc condyloid foramen gf glenoid fossa tympanic fenc fenestra cochlaeae mp mastoid process tr tympanic ring ognized its transitional nature. This is confirmed by the auditory region. The mastoid is less markedly de- veloped along the posterior margin of the basicranial region and much less extended over the auditory cavity. The tym-panic bulla is large for a machairodont and highly inflated, especially dorsoventrally. There is apparently little extension of the hypotympanic sinus into the mastoid process, although this point requires further investigation. mastoid processes, which are the most conspicuous ex— ternal features of the basicranium (figs. 6, 7). In Some specimens this overgrowth of the mastoid process is so great that it completely bridges the external audi- tory meatus and is in contact with the base of the post- glenoid process. In almost all specimens the breadth anteromedially equals that of the auditory bulla. In fact, as Merriam and Stock point out (Merriam and Stock, 1932), in many skulls the bullae appear as slight 102 swellings on the inner side of the heavy mastoid. In only one specimen described by them (University of California, no. 11256). and a few immature skulls ex— amined by the writer is the bulla larger than the' mastoid. The paroccipital forms a distinct leaflike process that projects backward much as in HopZOphoneus and not like that of E usmilis. INTERNAL STRUCTURE OF THE AUDITORY BULLA The tympanic itself is flask shaped, with a long tubu- lar meatus similar to that of Hyaena. In the majority of skulls it is highly inflated and has a steep medial wall. The auditory meatus is roofed by the squamosal, which also forms the anterior wall. The posterior wall is formed of the mastoid. In specimens in which the mastoid does not come in contact with the postglenoid process the floor is formed of a narrow wedge of the tympanic. This wedge becomes narrower but persists even if completely covered over by the mastoid. The cavity of the bulla is divided by a septum which is not, however, in the same position as that of Felis, and in the writer’s opinion is not a septum bullae. The septum in Smilodon is a horizontal sheet of bone di— viding the bulla into dorsal and ventral parts. The dorsal or upper chamber is the smaller. The hypotym— panic sinus is almost entirely dorsal of the cavum tym— pani and continues into the paroccipital. The much more extensive ventral chamber containing the acous- tic portion of the ear extends from the foramen lacerum medium to the base of the paroccipital process and extends laterally into the mastoid process, which is hollowed out and lined with the tympanic. Merriam and Stock describe essentially the same condition. They term the two divisions the outer and inner cham- ber. The ventral chamber, however, is “outer” only anteriorly, where of course it communicates with the external auditory meatus. On the other hand, the “inner” chamber of Merriam and Stock extends for- ward, beyond the ectotympanic chamber not only me- dial to, but actually above that chamber. It is topo- graphically more accurate, therefore, to term the two divisions upper and lower. The lower or tympanic chamber extends medially to cover all of the petrosal except a small portion of the promontorium just around the‘fenestra cochleae. Just below the promontorium at this point a narrow slit— like aperture provides communication with the upper chamber. From the inner roof of the latter several ridges radiate to the lateral margins. In many speci- mens one of these is strongly enough developed vir- tually to divide the chamber into an outer and inner portion. SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 THE STRUCTURE OF THE MIDDLE AND INNER EAR The external auditory meatus extends very far into the tympanic cavity. It is a narrow tube with a very thick floor formed, as stated before, of a thin wedge of the tympanic underlain by the mastoid. The external opening is very far forward. From this the meatus slants posteriorly and dorsally. The crista tympani is thus obliquely placed, the lowest part being just oppo- ' site the internal opening of the Eustachian tube. There is no extension of the hypotympanic sinus along the sides of the meatus. The dorsal chamber, hOWever, extends above the meatus for almost its entire length. The promontorium-is large and broadly oval. It slopes gradually and equally in all directions. The fenestra cochleae is also large and round, and faces ‘ posterolaterally. Because the septum lies just above and anterior to the fenestra, it opens into the ventral chamber. The fenestra vestibula faces anterolaterally. Lat- eral and anterior of it is the very large fossa for the tensor tympani. The epitympanic recess is deep, ex— tending well under the roof of the meatus. A short sulcus facialis extends from the fenestra vestibuli to the base of the ridge leading downward and somewhat laterally to the stylomastoid foramen. This foramen lies far forward because of the extreme anterior exten- sion of the mastoid process. A ridge along the anterior margin of the mastoid process is pierced by a canal that evidently formed the bony third part of the facial canal, which is thus almost vertical. BASICRANIAI. FORMINA There is no alisphenoid canal. The postglenoid foramen, which varies in size but is minute in some specimens, is entirely hidden by the coalescence of the mastoid and postglenoid processes. The condyloid foramen and the foramen lacerum posterius are some- what separate, but connected by a common groove. The degree of separation is varied. In some skulls the two foramina are about as close together as those of the lion and tiger and may be said to have a common opening. In others they are as far apart as in the dog and the groove connecting them is shallow. It is in- teresting that in the true felid, Panthera atmw con- temporary with Smilodon, the two are well separated. Merriam and Stock report that only 4 or 5 of a total of 20 specimens have a condition resembling that of Fall's. The carotid canal was not conspicuous in any of the skulls examined by the writer and Merriam and Stock do not describe it although the position is indicated in one of their illustrations (1934, pl. 15, fig. 1). The carotid artery was evidently minute in relation to the size of the size of the head in fact, possibly degenerated AUDITORY REGION beyond that of F dis The posterior carotid for amen opens into a common fossa with the foramen lacerum posterius and is also inconspicuous. SUBFAMILY NIMRAVINAE DINICTIS (OLIGOCENE SPECIES) EXTERNAL CHARACTERS Many specimens of Dinictz's, like those of Hoplo- phoneus, have no bulla. There are more, however, in which parts of the bulla are preserved, and In all cases these specimens are also more complete otherwise. In the skull of a young individual of Dim'ctis, U. S. N. M. 15889, collected from Niobrara County, VVyo., almost the entire anterior part of the bulla is intact (fig. 8). An American Museum specimen, figured by Matthew (1910) as Dinictis squalidens Cope also has a well- preserved auditory region with enough of the bulla to show clearly its shape and size. The parts of the bulla that remain do not in any way I correspond to the anterior chamber of the bulla of the recent Felidae. In the National Museum specimen, for example, the anterior portion of the bulla on the left side extends in contact with the basisphenoid about halfway along the medial margin of that bone. No flattening or difl‘erentiation distinguishes this medial portion of the bulla from that immediately surround- ing the auditory meatus. On the right side only a cir- cular rim of bone around the auditory meatus remains. The broken edge 13 irregular and there 1s no trace of a septum. Impressions on the overlying bones, and also the por- . tions which remain, show that the bulla in Dim’ctz's must have been very large and well inflated. It ex- tended from a point well beyond the base of the post— glenoid process anteriorly, almost to the edge of the skull laterally and posteriorly to the base of the paroc- cipital process. The inflation was even, giving the bulla a globular shape similar to that of the modern Canidae. The external auditory meatus faces laterally and only slightly forward differing markedly from H oplo- p/Loneus in this respect. It is oval in outline and formed almost entirely of the tympanic. The two legs are almost in contact across the roof excluding the . squamosal. The mastoid process, although more prom- inent than in the living Canidae and Felidae, is small compared to that H opZophoneus. It consists of a rugose knob of a size usual for Procyon. The paroccipital process projects backward as a flat- tened, triangular lobe very like that of Daphoneus. INTERNAL STRUCTURE OF THE BULLA AND MIDDLE EAR The auditory cavity proper is shallow, as is usual in dinictids, and in contrast to Hoplophmwus. The an- 229929—53———3 103 IN FOSSIL FELIDAE terior part is roofed by an extension of the alisphenoid that meets the basisphenoid laterally and is in contact with the promontorium by a narrow process. From" the anteromedian corner a ridge runs parallel to the raised rim of the basisphenoid. Lateral to this, aj groove marks the position of the Eustachian tube, and medially a similar groove leads into a large open space between the posterior margin of the alisphenoid and promontorium. This condition is unlike that of either the Canidae or Felidae where the alisphenoid meets the base of the promontorium and completely roofs the cavity, somewhat as in the Ursidae. The epitympanic recess is relatively shallow and does not extend far under the meatus. There is a conspic- uous fossa in the squamosal just anterior of the base of the mastoid process. This is somewhat similar to the suprameatal fossa of the Procynidae but it is deeper, and more medial and posterior in position. The promontorium is pear-shaped, much as in Daphoenus. The fenestra vestibuli is small and faces laterally. A narrow spur bridges the space between this and the mastoid. Along this a groove passes from the fenestra vestibuli to the large round foramen stylo— mastoideum primitivum. From this a wider groove deeply excavated in the knob like mastoid continues obliquely downward and slightly forward along the peduncle to its tip. This groove undoubtedly is the external part of the facial canal and marks the exit of the facial nerve from the skull. The fenestra cochlaeae faces postero—laterally and is located very far back—again a similarity to Daph’oenus. BASICRANIAL FORAMINA _ An alisphenoid canal, whose posterior opening is in a common fossa with the foramen ovale, is present. The position of this fossa is much as in H oplophoneus, that is, just medial to, and on a line with, the anterior rim of the glenoid fossa. There is a large postglenoid foramen. The carotid. canal lies in a distinct groove in the basioccipital extending from the foramen lace- rum medium to the posterior medial corner of the bulla. The medial margin of the promontorium meets a process from the basioccipital which forms a roof for this canal for a short distance. The posterior caro- tid foramen is at the extreme postero-medial corner of the bulla. Just adjacent to it but entirely separate is the foramen lacerum posterius. The condyloid fora- men is large and situated just behind and slightly medial to the depression in the rim of the auditory cav- ity, which, when the bulla was present, marked the common exit of the foramen lacerum posterius and the posterior carotid foramen. 104 { SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 O‘ :_ FIGURE 8.—l)inictis felina Leidy, I,“ S. National Museum 15889 ; a young individual, x11é. AUDITORY REGION IN FOSSIL FELIDAE 105 FIGURE 9.—Dmictis cyclops (Cope). U. S. National Museum 16558, x 1. DINICTIS CYCLOPS COPE (JOHN DAY SPECIES) The matrix has not been removed from the remnants of the large completely ossified bulla which was evi- dently present in the type specimen, American Museum of National History 6930. Further preparation, which would remove the cast of the interior of the bulla formed by the matrix, did not seem necessary as a skull in the National Museum (16558) from the same locality also has the floor of the bulla broken away but with no hard matrix, so that the overlying well-preserved structure is exposed (fig. 9). This is closely similar to that of the thite River dinictids, except in two 106 0 very significant respects. The roof is more completely ossified, with the alisphenoid meeting the base of the promontorium laterally and forming the anterior mar- gin of the large foramen lacerum medium medially. More important still, there appears to be a trace of a septum bullae. This is- actually represented by only a low broken ridge, but it is in the same position as that of Felis and the anteroexternal surface of the promon- torium is flattened and grooved in such a way as to indicate strongly the presence of a well-developed anterior chamber. If this interpretation is correct, however, the chamber was relatively large and well inflated, similar to that of Felz's rather than of Pan- tlwm. The basicranial foramina present no significant change from the condition in the Oligocene genera. There is an alisphenoid canal with a large foramen rotundum transversely placed. The postglenoid fora- men is unusually large. The condyloid foramen is also large and well separated from the foramen lacerum posterius. The posterior carotid foramen is large and, although posterior in position, is separate from the foramen la- cerum posterius. The carotid canal is represented by a deep groove extending directly forward from the pos- terior carotid foramen, along the medial margin of the promontorium, to the foramen lacerum medium. NIMRA VUS ‘The auditory region of the White River species, Nimrarus bumpy/leis does not differ in any important respect from that of Dim'ctis except that the bulla, judging from the portion which remains in the type specimen and the cast of the interior of the bulla present on one side, was smaller and less inflated. The basi- cranial foramina are the same in size, number and ar- rangement. The John Day species Nimmavus gomphodus and Nimmvus (Archaelums) debih's have remnants of a highly inflated, well rounded bulla. These remnants in Nimmvus debilis consist of a broad circle of bone around each auditory meatus. In shape and symmetry they strongly suggest an anterior chamber. There is no trace of a septum so that if a division of the bulla ex- isted in these early forms the septum must have been one . that did not reach the roof of the auditory chamber. Moreover, if an anteroexternal chamber existed, it was relatively large and highly inflated as in most species of Feh's. This is in contrast to the Pseudaelurinae. SUBFAMILY PSEUDAELURINAE ' AMERICAN GENERA The auditory region of Pseudaelums intrepédus has been admirably described by Stock (1934, pp. 1052* SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 1053). This description is summarized here, with a few notes for the sake of comparison. The bulla, which although completely ossified is small, is divided into two externally visible chambers. The anterior chamber is much the smaller and very much flattened, as in Pimthem and certain tropical species of Felis. The posterior portion is globular, very much » higher than the anterior,and has a steeply sloping me- dial wall. The auditory meatus is triangular, with no lip or tubular prolongation. The anterior wall is in contact with the base of the postglenoid process. The posterior wall meets the mastoid process. . The floor of the meatus appears to be composed only of the squa- mosal. The mastoid process is but little developed and en- tirely separate from the paroccipital process. The latter is a triangular flattened lobe that is directed backward much as in Bap/menus. Compared with the small size of the bullae, the basioc— cipital region between them appears very broad. ' The cranial foramina are transitional. There is an alisphenoid canal. The postglenoid foramen seems to have been very minute. (This part of the skull is crushed so that the size and position could not be ex- actly ascertained.) The posterior lacerate foramen is large and well removed from the condyloid foramen. The carotid canal could not be traced but the posterior carotid foramen apparently opened into the foramen _ lacerum posterius. ASIATIC AND EUROPEAN GENERA Metailums of the upper Miocene of China, as de- scribed by Teilhard de Chardin (1945) has an auditory region closely similar to that of Pseudanm-us. The bulla is two chambered, with the anterior external chamber much the smaller and flattened, and the pos— terior chamber globular much like that of Felis. Therailums from the Pliocene of France (Piviteau, 1931) also has a flattened anterior chamber to the bulla, but this is much smaller in relation to the highly inflated posterior chamber than in Metailurus. In both Metailwus and Themz'lurus, however, the basicranial foramina show a' notable advance in a feloid direction. There is no postglenoid foramen, no alis- phenoid canal and the carotid and condylar foramina are closely connected withthe foramen lacerum pos- terius.‘ SUMMARY AND CONCLUSIONS Two facts stand out clearly from the foregoing de- scriptions: 1. The auditory region in the Oligocene Felidae is distinctly canoid both in the absence of a septum bullae ' ‘ AUDITORY REGION IN FOSSIL FELIDAE and in the form, number, and position of the basicranial foramina. 2. The auditory region in the post—Oligocene Felidae (Machaerodonts as well as true felines) has the diagj nostic characters of the Feloidea. So impressed was Teilhard de Chardin with this dis- tinction that he based his classification upon it, but without any phylogenetic implications, as he expressly states. The Oligocene Felidae, the Paleofélidés of his classification, are sharply separated from the post- Oligocene Neofélidés. These two major categories are subdivided into normal and saber-tooth types. This arrangement, especially when presented in diagram- matic form, brings out forcibly the parallelism which is such an essential feature of the family, but leaves the phylogenetic relationships very much in doubt. (It also does not express the parallelism with entire correct- ness, since there are both saber-tooth and normal type canines in the Nimravinae and Pseudaelurinae.) The Asiatic‘record, with which Teilhard’s classificar tion is primarily concerned, commences with the Mio- cene. As he points out no “primitive” Oligocene cats are found in China, even in otherwise richly fossilifer- ous beds of that age. The situation in North America is quite different. The Oligocene record of the family is well documented and, although few Miocene and Plio- cene specimens are known at the present time, they pro- vide a series of transitional forms linking the early Machaerodonts with the Pleistocene Smilodon, and the Nimravinae with the Felinae. It seems reasonable tc suppose, therefore, if the currently accepted phylogeny of the ,Felidae first proposed by Matthew (1910) is cor- rect, that an evolution of the auditory bulla toward in- creasing complexity took place in both subfamilies. In the Machaerodonts, a horizontal septum was formed, sdmething like that of the Hyaenidae, dividing the cav- ity of the bulla into a lower, anterior chamber and an upper, posterior chamber. In addition, radiating raft- ers and septae complicate the walls of the posterior chamber, much as in certain modern mustelines such as the wolverine. I 1 In the Felinae, the septum was formed in the posi— tion of that of F elis but was at first an incomplete sep- tum similar to that found in certain of the Canidae. Increasing ossification in this region produced a com- plete septum that divided the bulla into the typical anterolateral and posteromedial chambers. l The basicranial foramina underwent a transforma- tion as the venous and arterial system of the head changed from a canoid to a feloid type. This evolu— tion, like that of the septum bullae, was a gradual thing that first developed to different degrees in individuals ‘and was only slowly fixed in the entire population. 107 It is possible, of course, to insist on the rigid homol- ogy of the two-chambered bulla and on this basis to exclude all of the Oligocene genera, Nimrmbus and Dim'otis as well as H oplophoneus and Eusmflz's, from the ancestry of the Felinae. Under this hypothesis such ancestry must be sought in a series entirely inde- pendent of the North American fossil forms as we know them. This view has not been without its defenders. Cope originally separated all of the fossil Felidae, including Pseudaelurus (which, of course, he did not know from complete North American specimens) from the modern family. The basis for his Nimravidae, as a later dis- cussion made clear, was the nature of the basicranial foramina. - ’ Gregory’s classification (1939) follows a similar pat- tern. His section Machaerida apparently includes both the Machaerodontinae and the Nimravinae, and the evolutionary series he erects, on the basis of the auditory bulla, consists of Paleopm’onodon ewypto- procta —>Felz's. Of course, he considered this sequence only a morphological series illustrating the postulated evolution of the auditory bulla. Nevertheless, if the auditory bullae did evolve in this way, the fossil F eli- dae are automatically excluded from the ancestry of Felis. No known fosil felid has an auditory bulla at all resembling that of Cryptoproota. Aside from the fact that phylogenies such as these do not correspond to the fossil record as we know it and ignore the transitional stages between the Nim- ravinae and Felinae, in the writer’s opinion there is little in the morphology and embryology of recent forms to warrant such a rigid application of the prin- ciple of homology. Since, in any case, a transforma- tion of the venous and arterial system of the head must have taken place (Paleopm'onodon, like all Oligocene carnivores, has a canoid type of basicranial foramina) a review of the whole question seems in order. HOMOLOGY or BASICRANIAL FEATURES or THE EELOIDEA SEPTUM BULLAE FORM AND POSITION OF THE SEPTUM IN THE FELOIDEA ' It is well known that the form and position of the septum, and consequently of the two chambers into which it divides the bulla, differ very much in the Viverridae and Felidae, and even more widely in'the other families usually included in the Feloidea. In the Viverridae the septum, which is really the posterior wall of the anterior chamber, is in contact with the basisphenoid medially for some distance so that the tympanic chamber is entirely anterior in position and 108 the entotympanic posterior. In the typical Viverridae the anterior chamber is always the smaller, and some- what flattened. The size of the posterior chamber may vary, but these relationships remain the same. In the F elidae the septum, also the posterior wall of the an— terior chamber, has no contact with the basisphenoid, but curves posteriorly and laterally from the antero- medial corner of the bulla and meets the crista tympani at a point just opposite the stylomastoid foramen. The tympanic takes no part, therefore, in the medial wall of the bulla which is formed throughout by the ento- tympanic in contact with the bones of the midline of the skull. The chambers formed are anterolateral and posteromedial. In the Felinae, as in the Viverridae, there is considerable variation in the proportions of the two chambers, but the anterior chamber (even if highly inflated, as in F elis catus) is always the smaller. In Panthem and some of the tropical species of Felis the anterior chamber is much flatter and very narrow antero—posteriorly. In Hyaena the principal septum extends latero- medially from a point just opposite the stylomastoid foramen across the fenestra cochleae to the medial coner of the bulla as in Felis but, since it is a hori- zontal sheet of bone extending posteriorly almost the whole length of the auditory cavity, it divides the bulla into a very large anterior ventral chamber, and a much smaller posterior upper one. The former. is the real bulla. The latter is not a separate chamber formed by an entotympanic, but a cavity‘in the base of the paroc- cipital process. Projecting from the horizontal sep- tum there is a ridge somewhat in the position of the septum of Cam's, but very much shorter in most speci- mens; It is the greater or lesser development of this ridge that gave rise to the various early statements, seemingly contradictory, as to the presence or absence of septae. Pocock (1916) sought to homologize the septum in Hyaena with that of the Viverridae. No doubt it does represent the posterior wall of the tympanic chamber, but in this sense it is equally homologous with the pos— terior wall of the bulla in the Canidae. It is certainly not, so far as form and position are concerned, homol— ogous with the septum in either Felis or Viverm. The structure of the bulla in Proteles is unique, and unlike that of either [lg/acne or the Felidae, but with some points of resemblance to that of the Viverridae. The anterior chamber of the bulla is flask-shaped and has a long tubular meatus resembling that of many of the Mustelidae. It appears complete in itself with a well-rounded convex posterior wall. This wall is paper-thin and composed entirely of the tympanic. The promontorium lies far forward and is completely SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 .~ .34).. FIGURE 10.—-V1‘verm‘cula indium rasse (Horsfield), U. seum 154917; young individual, x2. S. National Mu- FIGURE 11.—Felis catus Linnaeus, U. S. National Museum 188652, young individual, X2. AUDITORY REGION IN FOSSIL FELIDAE enclosed by the anterior chamber, the posterior wall of the chamber lying posterior of the fenestra cochleae. A well-marked sulcus in the periotic, with a raised bony rim, extends past the fenestra cochleae and into a bony canal between the mastoid process and the pos- terior chamber. This chamber is an entotympanic os- sification, but is not closely homologous with that of the Felidae and Viverridae. The anterior wall is ap- plied to the under surface of the anterior chamber and united to it by suture. Laterally, there is a suture be- tWeen the entotympanic and the mastoid which can be traced from the posterolateral corner of the auditory meatus downward and backward to the posterolateral corner of the posterior chamber. At this point it joins the paroccipital process—which is very large and leaf- like, and forms a deep cup which embraces the posterior Wall of the bulla. A large part of the lateral wall of the bulla is thus formed by the mastoid rather than by the entotympanic. Dorsally, the mastoid process is hollowed out into a deep rounded cavity. At the an- tero-medial corner of the posterior chamber a shelf is pressed against the posteromedial wall of the ante- rior chamber. It extends about halfway across the cavity of the bulla, swinging around posteriorly to merge with the posterior wall. A narrow strip of en- totympanic forms the lateral rim of the cavity in the mastoid process, but does not floor the cavity. In the ventral lateral wall of the posterior chamber a few septae radiate from the floor perpendicularly to the anterior wall. MODE OF DEVELOPMENT OF THE BULLA ‘ As would be expected, the differences in the form and position of the two chambers of the bulla in the adult 3“aeluroid” Carnivora are foreshadowed by the differ- jcnces in the mode of development. 1 In the Viverridae the anterior (tympanic) chamber idevelops very early and is completely ossified in adult form before there is much ossification of the posterior ‘ (entotympanic) chamber. In a very young individual ‘ Vivericula indica mase (U.S.N.M. 154917, fig. 10), . whose milk teeth were not erupted, the anterior cham- : ber is completely ossified. It is a horseshoe-shaped . demi—bulla precisely like that of the fossil forms I Daphoenus vetus and Paleop’m'onodon, and of the adult “ N andinia (a recent South American viverrid in which . the entotympanic remains cartilaginous throughout f life). Ossification of the entotympanic takes place “ first along the medial and posterior margins of the cartilaginous entotympanic, a strip between these os— sifications and the anterior chamber remaining carti— laginous until very late in development. The form of the tympanic changes very little. In the earliest stages, 109 the margins of this chamber are curved upward in such a way as to be almost in contact with the promontorium. This incurved margin forms the septum bullae of the adult. As the strip dividing the tympanic and ento— tympanic ossifies, the latter coalesces at the point of contact with the septum. A real interior wall to the posterior chamber is thus not formed, and the septum bullae is not composed strictly (as is sometimes stated) by the fusion of two sheets of bone, but of one—the tympanic—with only a slight participation of the ento- tympanic at the extreme ventral border. In a felid corresponding in age to the specimen of Viverricula mentioned above the only ossification of the bulla is the tympanic ring, a narrow rim of bone encircling the auditory region and lying parallel to and slighly above the promontorium. The space en- closed by this ring is very much greater than that en- closed by the anterior chamber in Viverricula. In a specimen of Felis catus that died at birth (fig. 11) only a very small part of the posteromedial border of the promontorium lies outside the tympanic ring. The upper margin of the ring is slightly incurved, but is not in contact with the basisphenoid or the petrosal. As ossification proceeds, the ring becomes filled in ven- , trally, leaving open the large oval external auditory meatus. Simultaneously with this ossification of the anterior chamber, ossification also commences from a tympanic center. This is at first entirely posterior, but the growing entotympanic appears to force the original tympanic ring downward and forward to an oblique position, leaving a wide space filled with cartilage be- tween the medial margin of the tympanic chamber and the basisphenoid. This is gradually filled in by bone developed, possibly, from both centers to form the medial border of the posteromedial chamber. There is no stage in Felis where the tympanic forms a com— plete chamber as in Viverricula, with the entotympanic cartilaginous. At birth the auditory region of 01mi8 is strikingly similar to that of F dis—much more than the auditory region of Felis resembles that of any viverroid studied. There is an ossified ring present in Uamis in essentially the same position as that of F elis, but it is flatter and crosses the promontorium dorsal and posterior to the ventral rim of the fenestra cochleae. In a specimen of Ganis dingo which diedat birth only the faintest rim of the posterior part of the auditory region is not en- circled by the tympanic ring (fig. 12). In Ua/m's as in Felis this ring shifts forward and downward as further ossification takes place. This shift is very much less in all cases than in F die, but varies according to the size and degree of the inflation of the fully developed bulla. The part anterior and ventral to the tympanic 110/ ring is formed by an outgrowth of ossification filling, in the space enclosed by the ring—except the auditory meatus. Posteriorly, ossification takes place from car- tilage as in the formation of the entotympanic in Feh’s (fig. 11). However, this proceeds simultaneously with the growth of the tympanic anteriorly and the two fuse indistinguishably without forming a complete sep— tum or separate chambers. Van der Klaauw (1931, p. 277) states that an ento- tympanic is developed in cartilage in Cam's, but seems to ossify out of the tympanic ring making the bulla simple and seemingly formed by the tympanic alone. FIGURE 12,—0ams dingo Mega-IthFX 5S. National Museum 8742, at On a later page, however, he warns against homolo- gizing the faint line Which crosses the bulla in meIs in very much the same position as a similar one in Felis marking the division between the tympanic and ento- tympanic. The former he says marks the position of the septum in Glands and so has nothing to do with the similar line in Felis because the septum of C'omz's is not 'homologous with the septum in Felis. This seems a very confusing statement. The fact is that the line on the bulla in Cam's does mark the division between the tympanic and entotympanic, that is, the position of the original tympanic ring, just as it does in F dis. The margins of this ring in Cam's, however, are not incurved even originally to the same degree as in Felis and fur— ther ossification in that direction does not take place so SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 no septum is formed from the tympanic. The partial septum found in some Canidae is a later development formed entirely by the inbent margin of the ento— tympanic. It is not homologous in the strict ontoge- netic sense with that of F elis, since the septum in Felis is formed from both the tympanic and entotympanic, but neither does it correspond to the septae and rafter which radiate from the crista tympani in such muste- lids as the wolverine. All of these forms, however, have this in common: The septae formed are neo— morphs ossifying from membrane relatively late in ontogeny, and probably late phylogenetically as well. In the Viverridae, on the other hand, the posterior wall of the anterior chamber ossifies very early and a com- plete anterior chamber is formed before any ossification commences in the entotympanic cartilage. As will be shown, this also agrees well with the probable phylo- genetic history of the bulla in the Viverridae. BASICRANIAL FORAMINA In all mammalian embryos, including that of man, there is a large postglenoid foramen. Intracranial blood is carried from the skull largely by the internal jugular. In some orders, notably the Artiodactyla, this is also true of the adult—the postglenoid foramen in the adult is enormous, and the external jugular the sole vein leading from the cranium. In man, an opposite development takes place; the postglenoid foramen closes shortly before birth, the external jugular atro— phies, and the lateral cranial sinus is drained by the internal jugular, which leaves the skull through the large foramen lacerum posterius. \ In all adult Carnivora there is some modification of the embryonic condition. This is relatively’slight in the Arctoidea, somewhat greater in the Canidae, and in the Felidae and Viverridae parallels the condition in man. Similarly, there are changes in the cranial arterial system from the embryo to the adult. These, however, are not inevitably linked with the venous changes, but can occur independently. In man, (Where the venous system is extensively modified in the adult) the internal carotid, which is a large and important artery in the foetus, remains so throughout life. In the Arctoid Carnivora (Ursidae, Procyonidae, Mustelidae) also, the internal carotid artery is large and conspicuous in the adult (half the diameter of the external carotid) with a strongly developed bony canal and a large con- spicuous posterior carotid foramen. Because the venous system in this group also retains much of the embryonic condition and the internal jugular is rela- tively small in size the foramen lacerum posterius is not AUDITORY REGION IN FOSSIL FELIDAE ”p70: ' p at c / \i‘ lll FIGURE 13.—Vulpes velow Frisch, U. S. National Museum 25425, young individual, x2. exceptionally large and does not conceal the condyloid jforamen. ‘ In the Felidae, both the venous and arterial systems ‘are profoundly modified in the adult. The internal ‘lcarotid. artery becomes vestigal, in the domestic cat limperforate throughout most of its length. The as— ‘cending pharyngeal (a branch of the external carotid) : takes over the intracranial portion of the circulation. 3This degeneration of the internal carotid reaches its (extreme in the domestic cat. In Panthem, however : (Davis and Story, 1943) , the internal carotid although ‘ minute in size, is perforate at least for some distance 3 beyond its origin. It passes through the middle ear . in the normal way, enters the foramen lacerum medium ‘ and anastomoses with the circle of Willis. This is in i contrast with the condition in the domestic cat where 1 the ascending pharyngeal is the dominant vessel beyond the foramen lacerum medium. w The Viverridae, although tending in the same direc- } tion as the Felidae (the reduction of the internal caro- ; tid) , achieves this in a different manner, and to different degrees in the various genera. In N andinia, accord- ing to Davis and Story (1943) the internal carotid is a relatively slender vessel, and it is described by Tandler (1906) as considerably weaker than the external caro— tid. In Herpestes on the other hand, the caliber is about the same proportionally as in the Arctoid Carnivora, but the canal is extremely short. In all of the Viverridae (except Na/ndinia, where the bulla is incbmpletely ossified), there is a well-developed bOny canal similar to that of the Mustelidae, and a. conspicu- ous posterior carotid foramen situated very anteriorly. The changes in the venous system in the Viverridae have proceeded much further. Virtually all of the genera usually included in this family even aberrant forms such as Cryptoprocta and H yam have a minute postglenoid foramen and a small concealed condyloid foramen. The Canidae have some characteristics that ally them with the Arctoidea, some with the Feloidea. The venous system is entirely “arctoid,” with a large post- glenoid foramen and conspicuous condyloid foramen. 112 The internal carotid is also well developed, but the course of the artery and the structure of the canal re- semble that of the Felidae rather than that of the Mustelidae, Procyonidae or Ursidae. There is no bony canal formed of the tympanic. Instead the artery runs forward to the foramen lacerum medium through a groove formed of the ‘periotic and the inbent margin of the tympanic. The posterior carotid foramen is con- cealed in a common fossa with the foramen lacerum posterius. SUMMARY AND CONCLUSIONS EVOLUTION OF THE INTRACRANIAL CIRCULATION As is pointed out above, all Oligocene Carnivora have a “canoid” type of cranial circulation. Even such forms as Paleopm'onodon, which have been con- sidered ancestral “feloids” because of the demi-bulla and viverroid features of the dentition, have a post- glenoid foramen and a large unconcealed condyloid foramen. A transformation of the cranial circulation. from the “canoid” to the “feloid” type must therefore have taken place—unless one is to consider the Felidae to have been created at the beginning of the Miocene. As a matter of fact, the stages in this transformation are well shown by the North American specimens of fossil Felidae. Pseudaelurus is a perfect intermediate form, in these respects, between Nimmvus and the Felinae. When the basicranial region of various other American pseudaelurines becomes known, still other stages will probably be demonstrated. It is possible, for example, that Adelphailums (now known only from _ an incomplete skull) had somewhat the same combina- tion of features as Metailurus of China, or Themz'lurus of the Pliocene of France, that is, no postglenoid fora- men and no alisphenoid canal, a large condyloid fora- men, and well-defined carotid canal with the posterior carotid foramen distinct from the foramen lacerum posterius. The machaerodonts show a similar evolution. As there is good evidence that this group was distinct from the Nimravinae as far back as the early Oligocene, these changes must have proceeded independently in the two lines. The degeneration of the carotid artery seems to have taken place at a faster rate than in the Felinae. The union of the posterior carotid foramen with the posterior lacerate foramen is more complete and more constant in Smilodon than in F elz's atrow. It is important to note that in both these genera, known from hundreds of specimens, the extreme condition, either way, exists as an individual variation. It seems probable, therefore, that all of these changes began as individual differences and that evolution to the SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 modern type consisted in the gradual fixation of such random variations. This is entirely in accord with the arrangement of the foramina as they actually occur in the living mem- bers of the Feloidea. There is not a feloid “type”. The changes in the venous and arterial system occur in different combinations and to different degrees not only ' as between the Viverridae and Felidae, but among the genera that comprise the respective families. The similarity of arrangement, therefore, is far better in- terpreted as progressive evolution taking place inde— pendently in various vertical lines of descent, rather than a phenomenon linked with phyletic branching. EVOLUTION OF THE AUDITORY BULLA The evolution of the auditory bullae in the Felidae presents a more difficult problem than that of the basi— cranial foramina, partly because of the imperfect preservation of the bulla in all OligOcene felids and partly because of the universal belief, amounting al- most to dogma, in the strict homology of the two- chambered bulla. However, it is seen from the foregoing discussion that there is no close correspondence in detail in the form and position of the septum which divides the bulla into two chambers in the Viverridae and Felidae— to say nothing of the Hyaenidae and Proteles. Fur- thermore, the mode of formation of the two chambers in the Felidae differs as much from that of the Viver- ridae as from that} of the Canidae. The similarly which exists (the formation in the adult of two complete chambers) is an end result rather than a step-by—step correspondence in detail. In fact, the early stages in the formation of the bulla in the Felidae resemble those of the Canidae more closely than those of the Canidae do these of the Viverride. The Canidae, in turn, differ from other “canoid” carnivores in having an entotympanic center of ossification. A demi-bulla of the type found in the recent Nam- dz'mla was undoubtedly “primitive” for all of the Viver— ridae. Gregory’s assumption that Vivermvus minutus‘ has such a bulla is based on an erroneous interpretation of a figure of Teilhard de Chardin (1914—1915, pl. 9, fig. 10). This figure and the description, and also an examination of the specimen of Vivermvus in the American Museum collection show that the structure in question is the promontorium. The bulla in View- mvus, as in all miacids, was unossified. Nevertheless, the general idea is apparently correct. The Viver- ridae did originate from various miacid populations (probably in different places and at slightly different times) ‘and, the writer believes, had a demi—bulla of‘ ’ AUDITORY REGION this type from the beginning. Possibly there never was a central type at any time, and such universally recognized genera as Pm'onodo’n, Herpestes, Viverm, Arjotz’ctz‘s etc. are each the result of the separate develop- of a vertical cline. There is absolutely no paleontological evidence that this kind of demi-bulla was primitive for the Felidae. Both the Machaerodontinae and the Nimravinae are as old, if not older, than the Viverridae. The earliest Oligocene representatives of both the former are highly specialized animals. Even supposing a common origin with the other Carnivora, from a miacid ancestry (which the writer considers doubtful, at least for the Machaerodontinae) , a long period of progressive evolu— tion separates H oplophoneus, Dim'ctz's, and Nimm’vus from Vieermvus or Paleopm’onodon or any form con- ceivably included in the Viverridae. ‘Incomplete though the bullae are in the known speci- mens of Oligocene felids, to anyone. who has studied the auditory region in these forms the evidence is indis- putable that the structure was simple and without a septum—certainly not a demi-bulla of the Daphoenus type. Therefore, it seems probable that the bullae evolved in the direction of increasing complexity, which improved the efficiency of hearing in both lines of descent, in various populations at various times, in various places. Since there was apparently more mi- gration and consequent interchange of genes than in the Viverridae, this evolution was more universal and produced the uniformity of type so characteristic of later members of the phyla. This is in accord with the known fossil record and with the size, structure, and habits of the animals. PROPOSED TAXONOMIC CHANGES . In accordance with the views expressed in this paper, the following modification andredefinition of the major taxonomic categories of the Carnivora are proposed. It is not supposed by the writer that this revision repre— sents the final word on the subject. Criticism and sug- gestions are invited. An attempt has been made, how- ' ever, to provide a basis for division into superfamilies that will be consistent with the morphology of the ‘forms and their geologic history, in so far as that is known. The superfamily divisions in current use are {especially objectionable because they cannot be prop~ .erly defined, and also because, having been based origi- ‘nally on modern forms, they have an archetypal sig— mificance which, when extended to extinct forms readily ‘1 lends itself to “proof” of erroneous theories of evolution. IN FOSSIL FELIDAE 113 SUMMARY OF SUPERFAMILIES AND FAMILIES Machairodontoidea Hoplophoneidae Eusmilidae Machairodontidae Diagnosis—This superfainily would include all of the genera listed by Simpson for the Machairodontinae, as well as the new forms from the Ash Hollow formation which are mentioned in this paper. The evidence sup- porting the separation of this group from the Felidae seems to the writer indisputable. Numerous features of the skull, dentition, and skeleton reveal its unity and its divergence from other carnivore groups. Of these features the most important are: . 1. The size and function of the incisors, which throughout the history of the group remain stout grasp- ing teeth. . 2. The tendency toward the reduction of the lower canine, which in its most extreme development becomes incisoriform and no longer shears against the upper canine. . , 3. The high degree of carnassialization. Even in the earliest representatives of the, group this is more ex— treme than in any of the true Felidae, and is unique among the Carnivora in'the part played by P. This tooth never'has the grasping function it has in the F elidae, but is a shearing tooth acting with the main carnassial, P4. In the Ash Hollow speCimens P4 is enormously enlarged and elongate while P3- is lost altogether. / . 4. The backward inclination and peculiar growth pat- tern of the carnassials, which causes the wear of these teeth to be oblique and maintain a cutting edge even in old rage. 5. The size, form, and function of the upper canine, which is not only always extremely long in proportion to the skull and has a broader basal diameter than in any felid, but is also more compressed and recurved. 6. The retention of primitive features, such as the small brain case and pronounced postorbital constric— tion, even in the Pleistocene members of the group. 7. The auditory region which, even in, primitive mem» bers, differs in its narrowness, depth, and the position of the tympanic bulla from that of the contemporary Dinictis. Compare, for example, figures 5 and 6, where the remnants of the tympanic bulla clearly show a large inflated structure in Din-ictz's and a compressed one in Hoplophoneus. In later forms this is fused with, and overgrown by the mastoid. In Dim'ctz's and Hoplo- phoneus, additional resonating chambers are produced, not by the development of a large inflated tympanic bulla as in the Felidae, but by excavation of the mastoid process. Septae, if formed, are radiating or horizon- 114 tal and do not truly divide the bulla into tympanic and entotympanic chambers. These characters, together with features of the skele— ton too numerous to mention here, but which have been described in an earlier paper (Hough, 1950) , seem suf- ' ficient justification for separation from the Felidae. In addition, that there is no evidence—only purely hy- pothetical considerations—that the machairodonts had a common ancestry with the Felidae, and certainly no evidence that any genera of the group entered into the composition of the modern family. In popular terms, the early machairodonts were not cats, nor did their descendants become cats in the strict sense of the word. They were throughout their history pseudo—felines, a primitive group, evidently world—wide in distribution judging from the known occurrences, which paralleled the true Felidae—but very remotely—in some features and which successfully over some 22,000,000 years filled an ecological niche similar to that now occupied by the modern cat family. _ It is the geological long range, and the ubiquity and diversity, which provide the justification for the super- family rank. H oplophoneus, E usmz'lz's, and Smilodon (to name only the typical North American genera), al- though possessing the common characters listed above, differ pronouncedly from each other in ways which make ancestral relationships difficult to trace, from the known forms at least. This diversity, which is a matter of combination of characters rather than a marked diver- gence of any one, points to apcommon ancestry either very remote or not very unified, that is, from different species or even difi'erent genera, rather than from one interbreeding population. It is also probably that the sample known is small in relation to the actual number of genera and species which at one time existed. Aeluroidea (or Herpestoidea, if strict rules of nomen- clature are followed) Daphoenidae Viverridae 2 Hyaenidae Diagnosi8.—Bulla always two-chambered with the entotympanic cartilaginous in the early forms (Da- phoenidae). Basicranial foramina canoid in Oligocene genera, postglenoid and condyloid foramina reduced in all later forms; carotid canal well-developed in all genera that have a completely ossified bulla; posterior carotid foramen large and anteriorly placed. Discussion—This is the most certain and stable of the categories. Known as early as the earliest Oligo- cene, or even perhaps latest Eocene of the Phosphorite beds of Quercy, France, the phylum has retained the same type of auditory bulla and the same trends in the evolution of the dentition throughout its history. The SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 inclusion of the Hyaenidae is questioned because of the lack of knowledge of the auditory region in I otitheréwm and in other early representatives that could be transi- tional between Hyaena and the more typical Viverridae. Cyno—feloidea Canidae Felidae N imravinae Felinae Diagnosis.—-Canidae and Felidae representlng two diverging branches, one retaining the primitive condi- tion of the undivided bulla with at most a partial, sep- tum, the other early developing a rudimentary septum which in later forms becomes complete, dividing the cav- ity of the bulla into two ch‘ambers. Basicranial foram— ina but little modified from the embryonic condition in the Canidae and early Felidae (Nimravinae); in the later Felidae becoming highly specialized with the com- plete closure before birth of the postglenoid foramen and atrophy of the internal carotid artery. ' Discussion—This is the most radical change pro- posed and will seem at first thought to be without foundation. Modern Canidae and Felidae, however, have more characters in common than usually recog— nized. Neither have any close aflinity with any other family—common opinion notwithstanding. Both families are highly specialized for their particular habits of life in all features of the dentition and skele- ton. Carnassialization in both has been brought to a high degree of perfection, in the Canidae in conjunc- tion with an equally effective crushing dentition, in the Felidae with all functions of the teeth sacrificed to that of shearing flesh. The Canidae are strictly cur- sorial; the Felidae semi-cursorial with an advanced type of foot mechanism adapted to their particular mode of attack. Traced backward, however, the char- acters of the two converge toward each other and also toward the primitive Viverridae. All writers on the subject have pointed out the viverrid characters of Psemlocynodiotis and the numerous resemblances, in all part of the anatomy, between Daphoenus and Dinictis. The Oligocene canids and felids, however, agree with one another and differ sharply from the Oligocene Viverridae (the Daphoenidae of this classi— fication) in the characters of the auditory region. Therefore, the earliest separation from closely similar contemporaries can be conceived to be on this basis. If only the Oligocene Carnivora were known, the writer believes that the major taxonomic grouping, if any were attempted, would certainly be on this basis. The Canidae and Felidae, nevertheless, must have di- verged before the Oligocene and pursued a separate evolution in dental characters. After the Oligocene 1 AUDITORY REGION IN FOSSIL FELIDAE this divergence became also marked in the basicranial region because of the more rapid evolution of the felid' branch in this respect. The result was the convergence in the Felidae of characters of the bulla and the venous and arterial system of the head toward the viverrid condition. Arctoidea Procyonidae ‘ Ursidae @Mustelidae lDz’agnosis—Bulla simple, without septae or rafters in all early forms and in most later ones. When septae and rafters do form, these are radiating ridges that do not bring about a bipartite division of the bulla. Increasing complexity of the bulla (which aids in reso- nance) takes the form of hollowing out of the mastoid, the formation of cancellous tissue in the mastoid and p‘arocciptal, and extension of the hypotympanic sinus along the sides of the meatus. Basicranial foramina p‘ersistently primitive with little modification from the einbryonic condition. Postglenoid foramen always large, the carotid canal a bony tube 1n the medial wall of the bulla, the posterior carotid foramen large and well separated from the foramen lacerum posterius. Discussion—The earliest procyonids have a very frypical auditory region indistinguishable in essential , atures from that of the modern representatives of the family. In fact, the earliest procyonids, except for the smaller braincase are almost identical with Bassam's- cus. The evolution of Procyon and N asua from these primitive forms presents no difficulty. , The relationship of the Ursidae is more obscure. However, their affinities as far as they are known seem closer to the Procyonidae than to the Canidae. - The early Mustelidae are clearly closely related to the early Procyonidae. There is a persistent tendency for the late Oligocene and Miocene carnivores with a procyonid type of bulla, such as Plesictis genetoides, ‘to develop mustelid characters in the dentition. The ‘more complex types of auditory region such as that of ‘Tawidea tamus could be easily derived from a simple jprocyonid type. ‘polyphyletic, with some addition of genera developed ‘from later Canidae, which also show mustelid features ‘in the dentition. A more exhaustive study of the fossil ‘mustelids and their relation to the modern genera is ‘needed before these affinities can be properly evaluated. 1 SELECTED REFERENCES Cope, Edwald D., 1884, The vertebrata of the Tertiary forma- tions of west. U. S. Geol. Surv. Territories. Hayden, vol. , 3, pp. 1—1009. ‘ Davis, Dwight, and Story, H. E., 1943, the carotid circulation in The family, however, is probably f O 115 the domestic cat: Z001. Ser. Field Mus. Nat. History, vol. 28, no. 1, pp. 5—46. Dobzansky, Theodore, 1941, Genetics and the origin of the spe- cies, 2d edition: Columbia University Press. Flower, W. H., 1869, On the value of the characters of the base of the cranium in the classification of the order Carnivora and the systematic position of Basso/Ms and other disputed forms: Proc. Zool. Soc. London, pp. 4—37. Gregory, W. K., 1939, On the evolution and major classification of the Civets (Viverridae) and other fossil and recent Carni- vora: a phylogenetic study of skull and dentition: Proc. Am. Phil. Soc.,‘ vol. 81, no. 3, pp. 309—342. Haas, O. A., and Simpson, G. G., 1946, Analysis of some phylo- genetic terms with an attempt at redefinition: Proc. Am. Phil. Soc., vol. 90, no. 5, pp. 319—349. Hough, M. J ., 1948, The auditory region in some members of the Procyonidae, Canidae and Ursidae: its significance in the phylogeny of the Carnivora: Bull. Am. Mus. Nat. History, vol. 92, art. 2, pp. 73—118. J epsen, Glen L., 1926, the oldest known cat, H oplophoneus char- rai: Black Hills Engineer, vol. 14, no. 2, pp. 1—6. 1933, American Eusmiloid saber tooth cats of the Oligo- cene epoch: Proc. Am. Phil. Soc, vol. 62, no. 5, pp. 355—369. Matthew, W. B., 1910, Phylogeny of. the Felidae: Bull. Am. Mus. Nat. History, v01. 28, art. 26, pp. 319—349. 1930, The phylogeny of dogs: Jour. Mammalogy, v01. 11, pp. 117—138. Merriam, John C. and Stock, Chester, 1932, Carnegie Inst. Washington: Publ. no. 422, pp. 3—231. Piviteau, Jean, 1931, Les chats des Phosphorites du Quercy: Annales de Paleontologie, vol. 20, no. 14, pp. 107—184. 1948, Un Felide du Pliocene du Roussillon: Annales de Paleontologie, vol. 34, no. 13, pp. 3—124. Pocock, R. I., 1916, The tympanic bulla in Hyaenas: Proc. Z001. Soc. London, pp. 303-307. Scott, W. B. and Jepsen, G. L., 1936, The mammalian faunas of the White River Oligocene, Part I, Insectivora and Carni- vora: Trans. Am. Phil. Soc., new ser., vol. 25, pp. 1—153. Stock, Chester, 1934. Skull and dentition of the American Mio- cene cat, Pseudaebums: Bull. Geol. Soc. America, vol. 45, pp. 1031—1038. Teilhard de Chardin, Pierre, 1914-1915, Les carnassiers de Phos- phorites du Quercy: vol. 9, pp. 103—182. 1945, Les Felides de Chine: Institute de Geobiologie, Pekin, Feb. 1945, no. 11, pp. 1—58. Turner, 1848, On the evidence of affinity afforded by the skull of carnivorous mammals: Proc. Zool. Soc. London, pp. 63—88. Van der Klaauw, C. J ., 1931, The auditory region of some fossil. mammals with a general introduction to this region of the skull: Bull. Am. Mus. Nat. History, vol. 67, pp. 1—352. Van Kampen, P. N., 1905, De tympanalgegend des Saugetier- schadels: Morphol. jahrbuch, vol. 34, pp. 321—722. Winge, Herluf, 1895, J ordfundne 0g nulevende Rovdyr (Carni— vora) fra Lagoa Santa, Minas Geraes, Brasilien: Med. Udsigt over Hovdyrenes indbyrdes Slaegstab. Carnivores fossiles et vivants de Lagoa Santa, Minas Geraes, Brésil. Avec un apercu des afiinités mutuelles des Carnassiers. E. Museo Lundii, Andet. Bind, Andet Halvbind, Kjobenhavn, pp. 1—130. Wortman, J. L. and Matthew, W. B.. 1899, The ancestry of cer- tain members of the Canidae, Viverridae and Procyonidae: Bull. Am. Mus, Nat. History, v01. 12, no. 6, pp. 109—138. Zangerl, Rainer, 1948, The methods of comparative anatomy and its contribution to the study of evolution: Evolution, vol. 2, no. 4, pp. 331—374. GICA \' 053 L {HY I Cranial Morphology of Some Oligocene Artiodactyla GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-H Cranial Morphology of Some Oligocene Artiodactyla By FRANK c. WHITMORE, JR. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY 1952, PAGES 117—160 GEOLOGICAL SURVEY PREOFESSIONAL PAPER 243-H UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1953 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. 5. Government Printing Ofiice Washington 25, D. C. - Price 35 cents (paper cover) CONTENTS . Page Cranial morphology of some Oligocene Artiodactyla—Con. Abstract ........................................... 117 Cranial morphology 0f Poebrotherium~Continued Introduction ——————————————————————————————————————— 117 Circulatory system of the skull—Continued Acknowledgments ............................... 117 Veins and venous sinuses ________________ Cranial morphology of some Oligocene Artiodactyla _____ 118 Dorsal sinus system _________________ Cranial morphology of M erycoidodon .............. 118 Basilar sinus system _________________ Bones of the skull ........................... 118 Sinus venosus ossis sphenoidalis ______ 0c0ipital ............................... 118 Nerves of the skull region .................... Basisphenoid ........................... 120 Cranial morphology of Leptomeryx ................ Alisphenoid ———————————————————————————— 123 Bones of the skull ___________________________ Presphenoid ———————————————————————————— 123 Tympanic region ___________________________ Orbitosphenoid ......................... 124 Pars petrosa of the periotic bone __________ Ethmoid and turbinals ___________________ 124 Middle ear and surrounding structures- - - - Vomer ................................ 126 External auditory meatus ________________ Preinterparietal and interparietal _________ 126 Pars mastoidea of the periotic bone _______ Parietal ............................... 126 Pneumatic sinuses __________________________ Frontal ________________________________ 126 Circulatory system of the skull _______________ Squamosal _____________________________ 127 Arteries _______________________________ Tympanic region ___________________________ 131 Veins __________________________________ Pars petrosa of the periotic bone __________ 131 Dorsal sinus system _________________ Middle ear and surrounding structures- - _ _ ’ 132 Basilar sinus system _________________ External auditory meatus ________________ 135 Sinus venosus ossis sphenoidalis- - - -‘__ Pars mastoidea of the periotic bone _______ 135 Morphological conclusions ___________________________ Pneumatic sinuses __________________________ 136 Bones 0f the skull ——————————————————————————————— Circulatory system of the skull _______________ 137 Primitive characteristics" ——.——: -------------- Arteries _______________________________ 137 Characterlstics of doubtful Slgnificance ........ Veins and venous sinuses ________________ 138 Ty mpan1c reg1on """ , ", """""""""""" Dorsal sinus system _________________ 138 anmve charactenstms- “ i"? """""""" . . Characteristics of doubtful Significance ________ Bas1lar s1nus system _________________ 139 Pneumatic sinuses ______________________________ Subsphenoid veins and sinus venosus Primitive characteristics _____________________ ossis sphenoidalis _________________ 140 Arteries _______________________________________ Nerves of the skull region .................... 141 Primitive characteristics _____________________ Cranial morphology of Poebrotherium ______________ 141 Veins and venous sinuses ________________________ Bones of the skull ___________________________ 141 Primitive characteristics ..................... Tympanic region ___________________________ 144 Anatomical peculiarities indicating habits, evolution— Pars petrosa of the periotic bone __________ 144 ary trends, relatlonshlps """"""""""""" Middle ear and surrounding structures- _ _ - 145 Phylogenetlc conclus1ons """"""""""""""" . Tylopoda ______________________________________ External auditory meatus--- ------------- 146 M ery c oi d o d onti d ae _____________________________ Pars mastmdea of the periotic bone _______ 146 Leptomerycinae ________________________________ Pneumatic sinuses -------------------------- 146 Summary of phylogenetic conclusions ------------- Circulatory system of the skull ............... 147 Selected bibliography ________________________________ Arteries _______________________________ 147 Index _____________________________________________ ILLUSTRATIONS FIGURE 14. M erycoidodon culbertsonii. Lateral view of skull ________________________________________________________ 15. M. culberlsonii. Ventral View of basis cranii ___________________________________________________________ 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. .30. 31. M. culbertsom'i. M. culbertsonii. . culbertsonii. . culbertsoniz'. . culbertsonii. . culberlsonii. . culbertsonii. . culbertsom’i. Poebrotherium wilsoni. P. wilsom’. P. wilsoni. P. wilsoni. Leptomeryx evansi. L. evansi. L. evansi. EEEEEE Internal view of basis cranii, from above _______________________________________________ Ventral View of basis cranii, with restoration of blood vessels ------------------------------ Frontal sections of the skulls of M. culbertsonii and Dicotyles labiatus ______________________________________ Thick section of skull, viewed posteriorly into cerebellar fossa ----------------------------- Thick section of skull in region of auditory bulla ________________________________________ Thick section of skull at level of post—glenoid processes ___________________________________ Thick section of skull, looking anteriorly into olfactory lobes ------------------------------ Thick section of skull, looking anteriorly through nasal cavity ----------------------------- Same as figure 1, with nasal cavity and pneumatic sinuses outlined ------------------------- Lateral view of skull- _ _ _ _ _ _ _ _ _ 1 ________________________________________________ Ventral view of basis cranii _______________________________________________________________ Thick section of skull, looking posteriorly from level of vagina processus hyoidei _________________ Thick section of skull, looking anteriorly into olfactory lobes ---------------------------------- Lateral view of skull ______________________________________________________________ Ventral view of basis cranii-___________________________________' ____________________________ Thick section of skull, looking anteriorly from region of bulla ___________________________________ III Page 147 147 147 147 147 148 148 149 149 150 150 150 150 150 150 151 151 151 151 151 151 151 151 152 152 152 152 152 152 152 153 153 153 154 154 154 155 155 155 159 Page 118 119 120 121 124 128 128 129 129 130 136 141 142 143 145 148 149 149 CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA By FRANK C. Wmmonn, J B. ABSTRACT A study of the cranial morphology of three Oligocene Artio- dactyla (Merycoidodon, Poebrothem’um, and Leptmeryw), ’based largely on serial sections, reveals many cranial charac- teristics found only in the most primitive Recent mammals. The Oligocene genera had several cranial veins which indicate that these artiodactyls were not far removed from a primitive insectivore—like ancestor. They had a well-developed internal carotid artery in contrast to the Recent Artiodactyla, very few of which retain this structure. The cranial circulation pattern of the Oligocene forms shows an evolutionary tendency in the Artiodactyla to abandon endocranial for extra-cranial paths. Other primitivecharacteristics are the lateral partitions of the pituitary fossa (representing the primitive side wall of the skull) and large temporal venous sinus in Merycoidodon, and the simple pneumatic sinus system in all three genera. The selenodont Artiodactyla exhibit an evolutionary trend toward the amastoid skull pattern now found only in bunodont families. The subarcuate fossa of the pars petrosa of the periotic bone in the Tylopoda has a peculiar shape, constant in the suborder and differing from the condition in other selenodont Artic- dactyla. This is added evidence that the Tylopoda must have separated from other artiodactyl lines of evolution no later than the middle Eocene. The simpler subarcuate fossa of Merycm‘do- don and Leptomeryw indicates their alliance with the suborder Pecora. On the basis of cranial structure, the family Hypertragulidae is divided into the subfamilies Hypertragulinae and Leptomery- cinae, both of which existed from the early Oligocene through the early Miocene. INTRODUCTION The Artiodactyla, or “even-toed ungulates”, form one of the largest and most varied of the orders of man!- mals. They are today near the acme of their develop- ment; their distribution is world-wide and they include in their numbers the pigs, peccaries, hippopotami, camels, deer, giraffes, cattle, sheep, goats, antelope and the tiny chevrotains of Asia and Africa. An examination of the Artiodactyla reveals several characteristics in common: hoofs, a more or less herbiv- orous diet, and a tendency toward a foot structure in which the weight rests mainly upon two toes of each foot. This mesaxonic type of foot, whose axis runs between the third and fourth toes, has given rise to the name of the order. Two other morphological peculiari- ties possessed by all the Artiodactyla are not externally visible but are very important. The first of these is the absence of the third trochanter of the femur, an eminence on the posterior side of the bone which serves as a muscle attachment in some mammals. \ The second and even more useful criterion is the presence upon the astragalus of a distal roller surface (for articulation with the navicular and cuboid bones) in addition to the proximal roller surface present in other mammals. Many years of study by zoologists have clarified the relationships among the many living artiodactyl groups, diverse as they are; but paleontology has re- vealed a tangle of problems in the many extinct artio- dactyl genera. The relationships of the extinct genera with each other and with modern types are often only a matter of conjecture; their ancestry is unknown. Therefore many uncertainties exist concerning the stratigraphic and paleoecologic significance of many extinct genera and species. Their morphology is,‘ of course, less well known than that of the modern Artic- dactyla. It is the purpose of this study to examine in detail the cranial anatomy of some of these extinct‘ genera, because endocranial characteristics are prob- ably nonadaptive, that is, unlikely to be influenced by the environment, and therefore useful in determining the taxonomic position of groups of animals. These studies were made with the aid of serial sections, a technique used by several workers in the study of fossil skulls (Darrah, 1936; Dunkle, 1940; Graham, 1933; Romer, 1937; Simpson, 1933, 1936; Sollas, 1916, 1920; Sollas and Sollas, 1914; Walton, 1928). The skull can be oriented in relation to the grinding surface to produce sections in any desired direction; the most common types of sections used are the sagittal (parallel to the plane of bilateral symmetry of the skull) and the frontal (at right angles to this plane). The studies presented here are based upon frontal sections. The sectioning technique used has been described in a previ- ous paper (Olsen and Whitmore, 1944). ACKNOWLEDGMENTS The author is especially indebted to Professor A. S. Romer of Harvard University, at whose suggestion this research was undertaken, for his assistance and en- couragement in every phase of the work. Many thanks are also due to the late Professor Thomas Barbour of the Museum of Comparative Zool- ogy, Harvard University; Dr. Childs Frick, Dr. G. G. 117 118 Simpson, and Dr. E. H. Colbert of the American Museum of Natural History; Dr. E. C. Olson of the University of Chicago; Dr. Glenn L. J epsen of Prince- ton University, and Mr. J. Leroy Kay of the Carnegie Museum, for the loan of specimens for comparison. Mr. F. Russell Olsen, of the Museum of Comparative Zoology, Harvard University, has by his skill made possible the construction of the apparatus used in this work. Apparatus used in preparing some of the specimens for study was purchased by a grant from the Elizabeth Thompson Science Fund of Harvard University. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA Because the serial-section method destroys the speci- mens used, it was decided to investigate genera of Which there are abundant specimens in paleontologic collections. The White River group of Oligocene age has yielded rich collections of mammals for many years, and it was found possible to obtain adequate specimens on which to base a study of the cranial anatomy of the artiodactyls, using three genera representing three dif- ferent families. The first of the genera, and that studied in greatest detail, is Merycoédodo’n, a member of the extinct family Merycoidodontidae (Oreodontidae), the “ruminating hogs” of Joseph Leidy. M erycoidodon is the most abundant mammalian genus in Tertiary deposits. The second genus studied is Poebrothem'm (of the Came- lidae) an ancestor of the modern camels; and the third is Leptomerym, of the family Hypertragulidae, which are diminutive, hornless, deerlike animals. SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 These three families comprised most of the Seleno- dont population of the Oligocene epoch of Nerth America; besides it was felt that they would reveal the stage of cranial evolution reached by the selenodont Artiodactyla in Oligocene time. CRANIAL MORPHOLOGY 0F MERYCOIDODON This study is based primarily upon serial frontal sections of a skull of M erycoz’dodon culbertsom'i (Leidy), M. C. Z. 6450, from the White River group (Oligocene) of northeastern Wyoming (figs. 14, 15). Sections were made at 2mm intervals through most of the skull. Posterior to the foramen ovale (fig. 15), an interval of 0.5mm was used because of the com- plexity of the structures in this region. In the following description, special attention is paid to those parts of the cranial bones which do not appear upon the surface of the skull, to the relations among those bones, and to the impressions left upon them by blood vessels and nerves. The external characteristics of the skull, as shown in figures 14 and 15, furnish points of reference in locating the features of the internal anatomy. The brains of Merycoz'dodon, and also those of P06- brotherz’um and Leptonwrym, have already been de- scribed in the basis of natural casts (Black, 1921; Tilney, 1931; Moodie, 1922; Bruce, 1883), and are not discussed in the present study. ' BONES OF THE SKULL OCCIPI’I‘AL The occipital bone contains, or is bounded by, sev- eral foramina for the passage of blood vessels and EF PT so PA FR NC N / FPP L LC PMX . , PM MX - fl MAE .. .1 .I o. 5-. ‘ x. PPO M ‘ V V ‘r‘ .4” A ‘5’ PAL 5 INCHES FIGURE 14.—Merycoidodon culbertsonii (Leidy). AS, alisphenoid bone. A80, anterior o ening of sinus canal. EF, ethmoidal oramen. FLA, foramen lacerum anterius. FM, mastoid foramen. FPP, postparietal foramen. FR, frontal bone. FHA, anterior subsphenoid for-amen. Lateral View, about X 1/2. IF, infraorbital foramen. L, lacrimal bone. L0, lambdoid crest. MAE, external auditory meatus. MX, maxilla. N, nasal bone. N O, nuchal crest. 00, occipital bone. Modified after W. B. Scott. Part of zygomatic arch removed. OS, orbitosphenold bone. PA, parietal bone. PAL, palatine bone. PM X, premaxilla. PPO, paroccipital process. PT, pterygoid bone. SQ, squamosal bone. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA nerves. The mastoid foramen (fig. 14, FM) is the exit of a canal which, passing posteriorly through the occi— pital bone, carries the mastoid emissary vein. This vessel is one of several draining blood from the great system of sinuses of the squamosal bone and the neigh- boring surface of the dura mater of the brain; it drains blood from the transverse venous sinus of the dura mater to the occipital vein. Another vessel draining venous blood from the cranium, in this instance from the base of the brain, 119 ran in the petro-basilar canal (figs. 15,21, PBC’) . This vessel was a large one, the inferior petrosal sinus. The venous blood flowed posteriorly into it from the cavern- ous sinus of the base of the brain. The sinus left the petro-basilar canal and extended posteriorly in a groove near the lateral edge of the basioccipital. Before leav- ing the petro-basilar canal, however, the inferior petro- sal sinus gave off a branch, the condyloid vein, which extended posteriorly in a groove on the endocranial side of the basioccipital. It left the skull through the PN . \‘ l I l PS 333 I V ‘v FSA , / l . // )y _,/ FSA Iv" / 85 i l / 1/ F0 : l ({1/ so ‘ \V , : a; .6 OTT i 3 ° \\//1/ EC 1 ’ ‘ PBC \‘J ° l PET 30 C ,0 I .V / FLP \ / OJ/ \f/ FSM PTP CF B 1 INCH FIGURE 18. —Frontal sections at the level of the first molar. of the skulls of Merycoidodon culbertsonu (Leidy) (M. C. Z. 5450) and Dicotylea labiatus (after Paulli, 1900). A, pneumatic part of nasal se tum. B, sinus in horizontal plate 0 maxilla. O, lateral nasal cavity. I ' maxillary extension of frontal sinus. S, bony nasal septum. This is typical of the living Non—Ruminantia, and is lacking in Merycoidodon. The two cavities of the nasal passage proper are found both in Merycoédodon and in Dicotyles, and are labelled A and 0 in figure 18. The cavity contained in the pneumatic part of the nasal septum(A) is in Dicotyles, in cross-section, about three times the size of that in M erg/ooz'dodon, due partly to the lateral ex- pansion of its lateral wall, partly to the fact that this CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA wall springs from a higher point on the nasal septum, or mesethmoid (S). This expansion of the pneumatic part of the septum in Dicotyles takes place at the ex- pense of the lateral nasal cavity (0), which contains the maxilloturbinals, the nasoturbinals and, posterior to the section shown in figure 18, the ethmoturbinals. The pneumatic part of the nasal septum in Mery- coz'dodon may, from its comparative simplicity, be re- garded as a primitive stage in the inflation of this septum. Anteriorly, the walls of the pneumatic portion of the nasal septum diverge and are continuous with the maxilloturbinals. Still farther anteriorly the mesethmoid is extremely heavily ossified, especially in the area midway between, the palate and the roof of the nasal cavity. In Merycoz'dodon oulbertsom'z', the mesethmoid forms a complete, strong bony nasal septum as far forward as the level of the first premolar, and continues for about 6 mm. anterior to this as a partial bony septum attached dorsally to the nasal bones. Thus it forms a vertical median septum in the nasal cavity for a dis- tance of 72 mm. in a skull whose anteroposterior length is 190 mm. Comparison with modern osteological ma- terial and a search of the literature reveal that very few mammals have a comparable degree of ossification of the mesethmoid. Such ossification was present in the extinct Rhinocerotidae, but has been greatly reduced in their living descendants. The order Pinnipedia also shows as much mesethmoid ossification (Flower, 1885). Dicotyles possesses a more completely ossified nasal septum even than Merycoz’dodon. Of 25 peccary skulls examined, all the adult specimens possessed a bony nasal septum reaching at least as far forward as the canine teeth, that is, within 25 mm. of the end of the snout. In Sus, the bony nasal septum also terminates anteriorly at the level of the canine tooth; however, the snout extends much farther in advance of the ca- nines than it does in Dicotyles. The conclusion forcibly suggested by these observa- tions is that Merycoidodon was, like Dicotyles, an an- imal of rooting habits. This theory is borne out by the fact that the strong nuchal crest of Merycoz'dodon indicates such powerful cervical musculature as is pos- sessed by Dicotg/Zes and by Sus. The vegetation of the Oligocene epoch seems also to have been such as would allow this mode of life, for it is well known that the early Tertiary flora was primarily lush, and that the increasingly dry climate of the West in Miocene and Pliocene time increased the area occupied by grasslands (Scott, 1937; Chaney and Elias, 1938). After the Miocene epoch, it is probable that the Merycoidodontidae abandoned their rooting habits, for 125 the nasals are greatly reduced in many genera, elimi— nating an important snout support. Also, the general snout structure in many laternMerycoidodontidae is much weaker than in Merycoidodon itself. The ethmoturbinal bones are extremely delicate, and it is surprising that in the Merycoidodon skull sectioned for this study they should have been preserved at all. They are attached not only to the orbital wall of the frontal bone, but also to the frontal where it forms the walls of the supraorbital extension of the nasal cavity (the anterior continuation of the frontal pneumatic sinus). This dorsal extension of the turbinals occurs in all mammals possessing large hollow supraorbital processes of the frontal bone. Examination of the serial sections reveals that Mery- coidodon has five ethmoturbinals. Their broken con- dition makes it impossible to determine whether they are ectoturbinals or endoturbinals except in one of the sections, which shows a strong scroll with a heavy base, easily identifiable as an endoturbinal. This is situated at the base of the orbital wing of the frontal bone, the farthest ventral position which can be occupied by an ethmorturbinal. The number of ethmoturbinals (five) possessed by Merycoidodon is typical of the Ruminantia (Paulli, 1900) as opposed to the Non-Ruminantia, which have six to eight. A striking difference from the modern Ruminantia is, however, the fact that in Merycoidodon the strongest ethmoturbinal is the fifth, or basal one, whereas in all modern ruminants the second ethmotur- binal is far stronger. The only modern mammals showing a strong de- velopment of the farthest ventral ethmoturbinal are the Carnivora, which, however, have only four ethmo- turbinals. The serial sections show almost no trace of the naso- turbinal bone, a scroll derived from the ethmoid cartilage and, in most mammals, fused to the frontal and nasal bones along the whole length of the roof of the nasal cavity. The only evidence of the presence of this bone is in two successive serial sections (fig. 18) , in which the roots of the nasoturbinals are seen spring- ing dorsally between the dorsal maxilloturbinals and the median nasal septum. Probably the nasoturbinal scroll itself was too delicate to be preserved. The maxilloturbinal bones are by far the best de- veloped of the turbinals in Meryooz'dodon. They are attached not only to the maxillae but also to the frontal bones, and extend from the level of the lacrimal fossa to the anterior nasal opening, a distance of 60 mm. (fig. 23). They lie anterior to the ethmoturbinals and below thenasoturbinals. The maxilloturbinals are not equally well developed throughout their extent, but 126 reach their maximum size in the region of the lacrimal fossa and at the anterior end of the nasal cavity. The maxilloturbinals may be subdivided into several parts. Beginning posteriorly, the first of these to appear are the dorsal maxilloturbinals which, at the level of the lacrimal fossa (fig. 23), spring from the nasal septum. Four millimeters farther forward the dorsal maxilloturbinals are fused to the frontal bones. Thus, for a short distance (and probably for a longer space in life, when the partitions were extended by cartilage) the nasal passage is divided into four pas- sages. Of these, the ventral one (pneumatic part of the nasal septum) was the most direct air passage. The dorsal pasage was most closely concerned with the sense of smell (an important function in Merycoidodon, which was macrosmatic; see Black, 1920). The lateral passages, one on either side, were connected through large apertures with the pneumatic sinuses of the max- illary bones, whose mucous membrane lining, together with that of the maxilloturbinals, probably played some part in warming the inhaled air. - Anterior to the region just described, at the level of the anterior part of the lacrimal fossa, appear the ventral maxilloturbinals, which are attached at their lower ends to the horizontal plate of the maxilla, di- rectly above the palatine canal. They form, on either side, a scroll that is rolled in a lateral direction and is not attached to the mesethmoid bone. Anteriorly these scrolls divide to form a small dorsal scroll in addition to the large lateral one. The bodies of the ventral maxilloturbinals are strong laminae, as much as 2 mm. thick. The scrolls, on the other hand, are delicate, and do not extend as far forward as the stronger laminae which support them. The bones which we shall term here anterior maxillo- turbinals are, in most living mammals, the only maxillo- turbinals present. They are the scroll—shaped bones visible in the dried skull as one looks into the anterior nares. The above observations on the turbinal bones make it plain that, in Meryooz'dodon, they are far more strongly ossified than in any living mammals except, perhaps, Dicotyles. This exceptional degree of ossifica- tion is undoubtedly a result of the heavy ossification of the mesethmoid cartilage which, in turn, is correlated with the probable rooting functions of the animal. VOMER The vomer is a long, slim, trough-shaped bone, which runs antero-posteriorly along the mid-line of the floor of the nasal cavity. Its concave side is dorsal, and in it rests the base of the vertical nasal septum. In the anterior portion of the nasal cavity, the nasal septum rests between two upturned flanges, one spring- SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 ing from the medial border of each of the palatine processes of the maxillae. These flanges are in contact along the floor of the nasal cavity, and diverge upward, forming a V—shaped trough like that of the vomer. This condition is not found in living Artiodetyla, but occurs in the Carnivora. PREINTERPARIETAL AND INTEBPARIETAL A preinterparietal bone is present in Meryco'édodon. It is very small and does not appear on the surface of the skull, being covered by the parietal. In the speci- men sectioned it occupies the dorsal wall of the brain- case for 6 mm. on either side of the midline, just posterior to the fronto-parietal suture. This bone is not found in adult Artiodactyla, but Wilhelm (1924) notes its presence in the young of 308, and it probably occurs in youth in many other genera. In spite of its possession of the preinterparietal, the skull of Mar-goat'- dodon examined here is an adult, as is shown by the molar teeth. The interparietal bone, which also appears in the young of modern Artiodactyla, is absent as a seperate ossification in the skull here studied. Not much importance can be attached to the presence or absence of the preinterpartietal and interparietal bones. Their independent existence is characteristic of an early ontogenetic stage in the ossification of the der- mal bones of the skull roof, and it is natural that the time of their fusion with the neighboring parietal should be subject to individual variation. PARIETAL The parietal bone (fig. 14, PA) forms most of the roof of the braincase. The parietal walls of the braincase are very thick and filled with diploé. . Toward the posterior end of the parietal, between the cerebrum and the cerebellum, the diploe reaches its maximum thickness of about 14 mm. Into this diplo'e there extends, on either side of the skull, a cavity that is the dorsal extension of the temporal venous sinus (fig. 21, SVT), a large blood vessel which is further discussed below. Within the cranial cavity, the parietal surface di- rectly below the sagittal crest is excavated by an an- tero-posterior groove that contained the sagittal venous sinus, one of the vessels draining blood posteriorily from the brain and from the face (fig. 22, SS) . FRONTAL The frontal bones (fig. 14, FR), by reason of their heavy supraorbital extensions and their postorbital processes, are strongly developed in M eryooidooflon as in most members of the family Merycoidodontidae. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA Anterior to the temporal ridges, the frontals form an almost flat surface between the orbits. On this surface, only a few millimeters on either side of the sagittal suture, are the supraorbital foramina. These are the dorsal openings of the supraorbital canals, which open into the dorsal side of the frontal pneumatic sinus. A continuation of the same canal leads from the ventral side of the supraorbital extension of the frontal sinus, through the lower wall of the supraorbital process, and into the orbit through a foramen in its roof. As in modern Artiodactyla, the supraorbital canal carried the frontal vein from the orbital plexus (or orbital venous sinus) upward through the frontal pneu- matic sinus and out through the supraorbital foramen. On the suture between the orbital wing of the frontal and the orbitosphenoid bone is situated the ethmoidal foramen (fig. 14, EF). This leads into a canal that runs posteriorly in the orbital wing as far as the cribri- form plate. It carries the ethmoidal artery, a branch of the ophthalmic artery. The ethmoidal foramen and canal are present in all modern Artiodactyla. Anterior to the postorbital constriction are the farthest posterior extensions of the frontal pneumatic sinus. In cross section, these extensions appear as two small cavities, about 3 mm in maximum diameter, one situated at either lateral limit of the diploic portion of the bone. In a section just anterior to the posterior nares, the frontal sinuses are considerably larger. Here each is incompletely divided into two parts: a medial cavity, still situated at the lateral edge of the diploé, and a lat- eral one occupying the supraorbital process. Both these cavities were separated from the olfactory lobes only by a very thin wall of bone, which in this section has been broken through. That the two were originally separated by bone was determined by cleaning the mat- rix from the inside of the braincase of the skull from which figure 1'6 was made. A cross-section of the posterior part of the nasal cavity shows the right frontal sinus, which here occu- pies the supraorbital process, widely open into the nasal cavity proper. A narrow extension of the frontal sinus reaches into the anterior processes of the frontals that thrust for- ward between the nasal and the lacrimal bones. In most sections this is a mere excavation of the frontal wall of the nasal cavity; in one section, however, it is separated from the nasal cavity by a thin wall. This suggests that the part of the frontal sinus immediately posterior to this section may also have been so separated. 127 SQUAMOSAL The squamosal bones (fig. 14, SQ) form a large por— tion of the lateral walls of the braincase; they are thick and heavy, and their relations to the neighboring skull elements are in places rather complex. The posttympanic process of the squamosal forms the entire posterior wall of the bony external auditory meatus (fig. 15, PTP). In this region the squamosal extends medially a distance equivalent to the length of the external auditory meatus (fig. 19). Its medial sur- face is the continuation of the inner squamosal surface which, farther dorsally, forms part of the braincase wall. Medial to the posttympanic process, however, this surface is in close contact with the lateral wall of the pars petrosa of the periotic bone (figs. 15, 16, PET). An anterior extension of the posttympanic process forms the medial part of the ventral wall of the external auditory meatus. The lateral end of this wall (the only part readily visible from the exterior of the skull) is formed by the tympanic portion of the meatus. In the modern Giraflidae and Cervidae, the posttym- panic process forms a part of the posterior wall of the external auditory meatus; but in no modern artiodactyl does it participate in the formation of the ventral wall, as in Merycoidodon. This participation of the squa- mosal in the ventral wall of the meatus must not be confused with the meatus auditorious spurius, present in some modern and a few fossil Artiodactyla, in which the posttympanic and postglenoid processes meet and fuse below the external auditory meatus of the tympanic bone. The meatus spurius simply covers the wall of the true auditory meatus; it is not a part of it. It is present in the Suidae and some Bovidae, and is very nearly complete in the Hippopotamidae. The serial sections show the squamosal bone to be thick and filled with diploic tissue, especially in the lower part of its cranial portion (fig. 22) and, to a lesser extent, in the zygomatic process. In the diploic bone of the cranial wall of the squa- mosal, dorso-medial to the postglenoid process, lies a cavity, 6 mm long, 6 mm wide, and 15 mm high (fig. 21, SVT). It tapers anteriorly to a blind end, and is surrounded on all but one side by the squamosal. The only other bone abutting upon it is the pars petrosa of the periotic, part of whose lateral side covers a large gap in the medial wall of the, cavity. This cavity has two openings, one into the cranium and another to the exterior of the skull. The former is a gap between the squamosal and the apex of the pars petrosa of the periotic (fig. 20, FJSP) . The latter is in the form of a canal that leaves the base of the cavity near its anterior end and extends posteroven- trally through the squamosal bone, just medial to the 128 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 xii, ‘ // Ll ”xxx/xx/x/x/x/xx/xx/xxaz-flaw‘: CV. WW” "5 l INCH FIGURE 19.——Merycoidodon culbertsonu (Leidy). x 1%. Thick section of skull constructed from section M9431, looking posteriorly into cerebellar fossa from level of auditory bulla. ,. . xi; //////xx;, .7 ,xx////xll, / ,[A‘WWWM fl fx/xn' WWW/M I// / ,4 /////////////¢ '/ vxxx I INCH FIGURE 20.——Merucoidodon culbertsonii (Leidy). x 1%. Thick section of skull from sections M33—38, in region of auditory bulla, looking anteriorly. Symbols used in figures 19—23 4450, ampulla of anterior semicircular canal. DPS, groove for dorsal petrosal sinus. FR, frontal. A0, area cochleae. DS, diploe of squamosal bone. FS, facial sulcus. ANF, area nervus faCialis. E0, ethmoidal crest. FSM, stylomastoid foramen. AS, alisphenoid. ENT, endoturbinal. FV, fenestra vestibuli. BO, basioccipltal. ET, endotympanic. HOF, hiatus canalis facialis. BS, basisnhenoid. F0, fenestra cochleae. H80, horizontal semicircular canal. OER, cerebellum. FOA, anterior carotid foramen. I ?, incus? CT, crista tympanica. FG, fissura glaseri. 1AM, internal auditory meatus. 0V, crista vestibuli. - FJSP, foramen jugulare spurium primitivum. 10A, groove for internal carotid artery; DMT, dorsal maxilloturbinal. FLA, foramen lacerum anterius. IT, incisura tympanica. DP, diploe of parietal bone. FM, foramen magnum. LCP, lateral clinoid processus. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA / . I ,‘ 11.7.33 ‘ m 4 ,, ”’/// a... ///////////////////// ////// 7% / ”/////////%//fl WW/ / A . _' m /////:V‘*' J; 7"”4? it? it l INCH FIGURE 21.——Merycoidodon culbertsonii (Leidy). X 1%. Thick section of skull from sections M42—54, at level of post- glenoid processes. Looking anteriorly. SS /’ ,//, ‘; ~‘,‘U // I" . / LCP .7 W . ,;/ , ---' 1/7/13 ch PF WMflM’) mfiVW/fl/fl?’z FLA WWW/r/‘EW ,, _ | lNCH FIGURE 22.—Merycoidodon culbertsom‘i (Leidy). x 1%. Thick section of skull from sections M57—77, looking anteriorly into olfactory lobes. Symbols used in figmes 19—23—Continued M, pars mastoidea. M2, second molar. M EJ mesethmoid. MF,‘ margo fissurae of squamosal. M 7%, margo tympanici of squamosal. MX, maxilla. NO, nasal cavity. 0, orbit. 0L, olfactory lobes. P, promontorium. PA, parietal. PAL, palatine. PBC', petrobasllar canal. BBWHH PC, pars cochlearis of pars petrosa. POP, posterior clinoid process. PET, pars petrosa. PF, pituitary fossa. PFM, nrocessus folii of malleus. PME, pneumatic part of mesetbmoid. POS, posterior root of orbitosphenoid. PVP, pars vestibularis of pars petrosa. RE, recessus epitympanicus. S0, sinus canal. SF, subarcuate fossa. SH, hypotympanic sinus. SMS, superficies meatus of squamosal. SO, squamosal. SS, sagittal sinus. S80, subsphenoid canal. SVT, sinus venosus temporalis. T, ectotympanlc. T0, temporal canal. TT, tegmen tympani. V, vomer. VOL, vena capitis lateralis. VPH, vagina processus hyoidei. V etc., groove for cranial nerves. 129 130 SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 FS FR NC 0 DMT . ME ENT // . I T .1». I /~‘*‘// /‘ -‘ it" .1 \\ _ . .‘r’x/M/W% .%\ /} «1‘ Yyl/fo‘k PME ‘-‘\‘\ Q I//’ /////’ MX "Hi-91‘ \. / / ' ‘:-:~..\ r, .,,,// %W l INCH FIGURE 23.——Merycoidodon culbertsonii (Leidy). x 1%. Thick section of skull from sections MSG—120, looking anteriorly through nasal cavity. - postglenoid process (fig. 20, T0). The external open— ing of this canal is through the foramen jugulare spu- rium (T0, fig. 15) between the tympanic bulla and the postglenoid process. The positions of the outlets of this cavity lead to the conclusion that it must play a part in the venous circulation of the skull, in close connection with the large venous sinuses of the posterior portion of the brain. The canal linking it with the exterior is, from its course and the position of its exit, the temporal canal. This canal, to some degree present in all mam- mals, carries the superior cerebral vein to its junction with the external jugular vein. The above—mentioned cavity in the squamosal is simply an enlargement of the temporal canal to form a venous sinus similar to those lining the cranial cavity, but surrounded by bone. The term sinus venosus temporalis is here applied to it. Its opening into the cranial cavity is therefore the fora- men jugulare spurium primitivum (van Kampen, 1905, p. 382). This corresponds to the foramen through which, in the embryological stages, the superior cerebral vein left the chondrocranium. The sinus venosus temporalis is found in no living mammals, to the best of the author’s knowledge: The only mention of its presence in fossil skulls is by Simp- son (1936) who reports the presence of an identical cavity in the squamosal bone of Oldfieldthomasia, a primitive notoungulate from the Eocene of Argentina. Merycoidodon and Oldfieldthomasz'a are both primi— tive mammals, with small brains relative to the size of the skulls and to the area of insertion necessary for their temporal muscles. It is therefore possible that the presence of the sinus venosus temporalis indicates that the small size of the brain and concomitant thickness of the diploic portion of the squamosal bone allowed the superior cerebral vein to attain a large size. Since the exit of the temporal canal (fig. 15, T0) is small, the sinus venosus temporalis must have served as a reser- voir for venous blood, rather than as a main drainage vessel. Blood probably flowed both into and out. of it through the diploic veins. In modern mammals, with their large brains, the dorsal cerebral vein and the temporal canal are of relatively minor importance. The lateral growth of the brain prevents any large veins from taking a dorso-ventral course around it; therefore all venous drainage of the braincase is along its roof (as the mastoid emissary vein) or along its base (as the inferior petrosal sinus). Another ramification of the cranial venous system is indicated by the presence of a canal running postero- laterally from the temporal canal, between the squa- mosal and tympanic bones. It has its exit just anterior to the external auditory meatus, through the postsqua- mosal foramen of Cope ( 1880). This foramen was not observed by Cope in Mcrycoidodon; it is very small in this genus and absent in some specimens. The postsquamosal foramen is reported by Cope to occur in the Hippopotamidae, Girafiidae, Cervidae, Antilopidae and Capridae among the Artiodoctyla. Still another canal of the cranial venous system ex- CRANIAL MORPHOLOGY OF tends backward along the suture between the parietal and squamosal bones from the frontal plane of the external auditory meatus to the plane of the condylar foramen), where it emerges upon the surface of the skull through the postparietal foramen 0f Cope (1880), (fig. 14, FPP). These foramina (there may be two or three on either side of the skull) are present in all the Merycoidodontidae but in few living Artiodactyla (the Antilocapridae, Cervidae, Antilopinae and Caprinae). Other aspects of the squamosal bone will be con- sidered in the discussion of the tympanic region. TYMPANIC REGION For purposes of discussion, this complex region will be divided into four parts: (a) the pars petrosa of the periotic bone; (b) the middle ear and surrounding structures, including the auditory bulla; (c) the ex— ternal auditory meatus; and (d) the pars mastoidea of the periotic bone. PARS PETROSA OF THE PERIOTIC BONE This bone, contained entirely within the cranial cav— ity (fig. 16, PET), is composed of two parts. The dorso-lateral portion is the pars vestibularis (fig. 20, PVP). It contains the semi-circular canals, and is situated mainly posterior, as well as dorsal to the pars cochlearis (fig. 20, POP). As has been pointed out, the pars petrosa is in con- tact laterally with the inner face of the ventral plate of the squamosal, and ventro-medially with the lateral border of the basioccipital. It reaches its greatest size posteriorly; anteriorly its dorsal surface slopes to its termination at a point lateral to the foramen lacerum medius. Just posterior to this point, the pars petrosa gives off a slim process which mounts dorso-laterally along the cranial wall of the squamosal. This is the processus perioticus superior. Its position in Mery- coidodon is nearer that of modern mammals than that of the Eocene OZdfleZdthomasia (Simpson, 1936) in which the process projects laterally along the floor of the temporal venous sinus. In Merycoidodon, this process is separated from the sinus by about 5 mm. of diploic bone. Posterior to the processus perioticus superior a groove extends backward along the dorsal crest of the pars petrosa (fig. 21, DPS). It is about 3 mm. long, and in life carried the dorsal petrosal sinus, which joined the transverse venous sinus at the foramen jugulare spurium primitivum, thus emptying blood from the midbrain region into the temporal sinus and canal. Posterior to the above-mentioned groove (figs. 16, 19, SF), is a depression, the subarcuate fossa, in the dorsal SOME OLIGOCENE ARTIODACTYLA ‘ 131 surface of the pars petrosa. In its center is a small, deep depression. The subarcuate fossa must have lodged the lobulus petrosus of the flocculus of the cerebellum, and small blood vessels probably passed ventrally from the floc- culus into the pars petrosa. Davidson Black (1920, p. 309) notes the similarity of the deep subarcuate fossa of the Merycoidodontidae to that of the Carnivora (such a fossa is also present in Rodentia and many Primates; Bolk et al., 1936, vol. 2, p. 89). Black con- trasts this condition with that of the living Arti- odactyla, in which, he says, the subarcuate fossa is shal- low or absent because of the absence of the lobulus petrosus of the cerebellum. This is true, so far as can be determined by examination of the literature and of dried skulls of recent Artiodactyla, except in the suborder Tylopoda, which have a very large lobulus petrosus. This condition will be discussed further in the section on Poebrothefium. The subarcuate fossa of Merycoidodon is smaller and much simpler than that of the living Tylopoda or of the contemporary Poebrotherium, and resembles very closely the fossa of the Carnivora. The presence of this fossa seems to indicate that Merycoidodon, like the Carnivora, Rodentia, and some Primates, possessed a motor reflex center that is present only in the Tylopoda among modern Artiodactyla. On the medial side of the parts petrosa is a large opening, the internal auditory meatus (fig. 16, MAI). Its course is directly lateral through about two-thirds the thickness of the pars petrosa. At its fundus, the internal auditory meatus divides into two parts (fig. 19). The dorsal branch is the area nervus facialis ( ANF), into which passes the seventh cranial nerve on its way to the facial canal. The more ventral of the two branches is the area cochleae (A0), through which the duct of the auditory nerve passes to the cochlea. Backward for a short distance from the internal audi- tory meatus, the facial canal lies in the pars petrosa. It then passes out of the pars petrosa, through the aper- tura tympanica canalis facialis, into the cavity of the middle ear, along whose roof it travels as the facial sulcus (fig. 19, SF). From the fundus of the internal auditory meatus extends anteriorly a very narrow canal, the hiatus canalis facialis (fig. 21, IIOF). It issues into the era- nial cavity through a foramen on the anterior slope of the pars petrosa. It carries the nervus facialis super- ficialis major, an anterior branch of the facial nerve, which extends anteriorly as the nerve of the pterygoid canal to the sphenopalatine plexus and ganglia. It is the equivalent of the palatine nerve of lower vertebrates. The facial sulcus, a groove on the ventro—lateral side 132 of the pars petrosa (fig. 19, SF), is the posterior con- tinuation of the facial canal. It extends posteriorly about 4 mm., attaining such a depth (about 3 mm.) that it might be called a recessus epitympanicus. Regard- . less of the terminology employed, however, this sulcus almost certainly carried the facial nerve, as it ends pos- teriorly directly above the stylomastoid foramen, the exit of the facial from the tympanic cavity (fig. 19, FSM). The central cavity of the pars vestibularis of the pars petrosa (fig. 20, PVP) is the vestibule (fig. 19, V). This cavity has in its ventro-lateral wall an opening, the fenestra vestibuli or fenestra ovalis, through which it communicates with the cavity of the middle ear. In the anteroventral wall of the vestibule is a small circular depression, the recessus sphericus. This, in life, contained the saccule of the inner ear. The posterior end of the vestibule is just anterior to the level of the stylomastoid foramen (fig. 15, F SM ) Ventrally, a horizontal crest projecting laterally from the body-of the pars petrosa separates the' vestibule from the fenestra cochleae, whichlies below it. This crest is the crista vestibuli (fig. 19, 0 V). Within the vestibule are several openings, leading to other parts of the cavity of the internal ear. One of these, near the posterior termination of the vestibule and on its medial side, is the opening of the aquae- ductus vestibuli, a bony canal running postero-laterally and opening upon the medial surface of the pars petrosa. This canal transmits the endolymphatic duct, which ends, in modern mammals, in a cul—de-sac be- tween the layers of the dura mater. Nothing need be said here concerning the semicir- cular canals. As is shown by the work of Turke- witsch (1933), the only differences that they exhibit within a mammalian order are those of dimensions, and such measurements must be based upon a large suite of specimens. The lateral side of the pars vestibularis of the pars petrosa is an eminence, the prominentia canalis later- alis, which is closely applied to the squamosal bone. Its lower edge forms the tegmen tympani (fig. 20, TT). The tegmen tympani, as the serial sections show, is simply a projection of the pars vestibularis over the tympanic cavity. In Merycoz'dodon this projection is far greater than in living Artiodactyla, with the result that the tegmen forms almost the entire roof of the tympanic cavity, whereas in modern artiodactyls it rarely forms more than half. When the pars petrosa of Merycoidodon is compared with that of 002's, which is typical of modern Rumi- nantia, it becomes apparent that the tegmen tympani of the former is borne relatively much lower on the SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 lateral side of the bone. This is a reflection of the fact that, in Merycm'dodon, the pars vestibularis of the pars petrosa is a more important element in the side wall of the braincase than in modern Ruminantia. The same comparison seems to hold with the Non—Ruminantia. The total antero-posterior length of the tegmen tym- pani is approximately six millimeters; it extends pos- teriorly from the level of the foramen j ugulare spurium (figs. 15, 20, T0) to that of the stylomastoid foramen (fig. 15, FSM). The tegmen tympani is absent in the anterior half of the roof of the tympanic cavity, which is formed by the squamosal (fig. 21). This is a rare condition in modern mammals, being found, according to van Kampen (1905, p. 345) only in the Marsupialia and Chiroptera. Medial to the tegmen tympani, directly anterior to the facial sulcus, and below the hiatus canalis facialis, lies a short, deep groove in the pars petrosa (fig. 20). This is the sulcus in which is inserted the tensor tym- pani muscle. From the posterior side of the fenestra cochleae (fig. 19, F0) a small canal runs posteromedially through the bone. This is the aquae—ductus cochleae which, like the aquae-ductus vestibuli, formed a path for interflow of lymph between the inner ear and the subarachnoid space between the arachnoidea and the pia mater of the brain. ' The lower part of the lateral wall of the pars petrosa, which forms most of the medial wall of the middle ear cavity, bulges somewhat into that cavity. The bulge, which is caused by the first coil of the cochlea, is known as the promontorium (fig. 20, P). The promontorium in Merycoz'dodon is conspicuous, but not so much so as in Oldfieldthomwsz'a (Simpson, 1936). No data are available as to the relative degrees of prominence of the structure in modern mammals. The cochlea, as revealed in frontal section, appears to possess 2% spiral turns, the same number as in modern ungulates. MIDDLE EAR AND SURROUNDING STRUCTURES Of the various cavities (usually termed “sinuses” and “recesses”) of the middle ear, the one underlying the auditory ossicles is the largest in Merycoz'dodon. This cavity occupies the hollow auditory bulla (fig. 15, B), and is thus surrounded on all but the dorsal side by the inflated tympanic bone. It is known as the hypotympanic sinus (fig. 20, SH). The upper bound- ary of the main part of the hypotympanic sinus lies at the level of the chain of auditory ossicles. An- teriorly, the sinus extends about 4 mm beyond the os- sicles (fig. 21, SH), and for a short distance is entirely surrounded by the tympanic bone; behind this point ' the tympanic is incomplete dorsally land the horizontal CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA part of the squamosal forms the roof of the sinus. The dorsal gap in the tympanic bulla is the “tympanicum- defekt” (Bondy, 1907). It is larger in M erycoidiodon than in modern Artiodactyla. In spite of the fact that Merycoidodon has extremely small auditory bullae, the hypotympanic sinus is rather large. This is, of course, because the bulla is entirely hollow, with no filling of cancellous bony tissue such as occurs in many Artiodactyla, including the later merycoidodonts. The sinus is shown at its maximum size in figure 21 (SH). In the Mammalia, the middle ear cavity may extend into two cavities dorsal to the auditory ossicles, known as the epitympanic recess and the epitympanic sinus. The epitympanic recess is the cavity lying im- mediately dorsal to the auditory ossicles. It is en- closed in the ventral wall of the skull (usually between the pars petrosa and squamosal) and composes the dorsal portion of the tympanic cavity proper. The epitympanic sinus, on the other hand, is an ac- cessory cavity of the tympanic cavity. Where present it lies in the squamosal or the pars mastoidea, and opens into the epitympanic recess. The epitympanic recess in Merycoidodon is a cavity about 2 mm. deep and 3 mm. long, situated dorsal to the deepest portion of the hypotympanic sinus (fig. 21, RE) . Its roof consists of three elements. The middle element is the slanting lateral surface of the pars petrosa of the periotic, and the lateral element is the facies epitympanica of the squamosal bone. This por- tion of the squamosal lies medial to the postglenoid process and forms the floor of the temporal venous sinus. The facies epitympanica is in contact with the pars petrosa; between them lies a small bone Whose identity is in doubt, but which is probably a piece broken from the tegmen tympani of the pars petrosa. This is the third element of the roof of the epitympanic recess. The living Artiodactyla in which the epitympanic recess most closely resembles that of Merycoidodon are the Cervidae and Camelidae. In both these families the recess is small, and roofed over as much by the pars petrosa as by the squamosal, but in the Suidae and Bovidae it is roofed mainly by the squamosal. The recess in the Tragulidae resembles that of Merycoz'd- odon except that the tympanic bone, in addition to the squamosal, forms its lateral boundary. This is because the “tympanicumdefekt” in the Tragulidae is smaller. The epitympanic sinus has less functional impor- tance than the recess, and is correspondingly more varied. In many mammals it is absent, but in others, i such as the Notoungulata (Simpson, 1936) it attains enormous size. 133 In Merycoidodon, the epitympanic sinus is absent, the part of the squamosal above the epitympanic recess being a solid plate containing no cavities. This is also true, so far as could be determined, of all the living Artiodactyla. In addition to the large cavities of the middle ear, there is in Merycoidodon a very small cavity, the incisura tympanica (fig. 20, IT), which lies just dorsal to the tympanic membrane. Its lateral wall is formed by the facies epitympanica of the squamosal, and its roof by an overhanging process from that bone. Ven- trally it is bounded by the tympanic bone. In the fossil it is open medially into the epitymanic recess, but in life this opening was covered by a membrane (the membrana shrapnelli or pars flaccida), a non- functional part of the tympanic membrane. Its lower border is the dorsal part of the sulcus tympanicus, the part of the tympanic ring in which the tympanic mem- brane was held and stretched taut. The position of the incisura tympanica in Mery- coz'dodon is the same as that in the Suidae. Data con- cerning its condition in the Ruminantia are incomplete, but it is known to be large in the Cervidae, and absent in the Camelidae and Tragulidae. The most striking external feature of the ear region (although smaller in Merycoz'dodon than in most mam- mals) is the auditory bulla (fig. 15, B). The most an- terior part of the bulla is, as in all other animals with small or medium-sized bullae, the styliform process. This slim anteriorly projecting extension is applied closely to the lower surface of the squamosal and, in Merycoz'dodon, branches at its anterior end into a medial and a lateral arm, each about 1 mm. long. It formed the lateral wall of the ostium tympanicum tubae (see above), and probably, as in living Artiodac- tyla, provided the origin for the levator veli muscle. In the living Cervidae and Bovidae the styliform process is present and probably performs the same functions as in Merycoz'dodon. In the living Cameli- dae the anterior wall of the bulla forms the lateral covering of the ostium tympanicum tubae, and there is only a suggestion of a styliform process. No process at all is present in Tragulus or the Suidae. Just posterior to the styliform process, the bulla of Merycoidodon is slightly notched for the reception of the eustachian tube, which passes medial to it. The bulla in Merycoz'dodon is a low inflated hemi- sphere of bone situated between the postglenoid process and the basioccipital. Its longest dimension is the antero-posterior one, and it does not project so far 7 ventrally as does the postglenoid process. Laterally it overlaps ventrally the facies epitympanica of the squa- mosal; medially it is separated from the basioccipital 134 by a broad groove that in life held the inferior petrosa] venous sinus (fig. 15, P30). Posteriorly, the bulla narrows to a ridge, which is suturally attached to the antero-lateral side of the paroccipital process of the oc— cipital bone (fig. 14). Here it forms a part of the medial wall of the articulation for the tympanohyal bone. In contrast with some modern Artiodactyla, the bulla is not fused to the pars petrosa of the periotic, and there is a gap between the two through which the internal carotid artery probably passed (fig. 21, F011). ' The bulla of Merycoidodon is smaller in proportion to skull size than that of any modern artiodactyl, although the Cervidae and Giraflidae have a small bulla. In most of the living genera there is a tend- ency to develop a large bulla, that is laterally compressed and reaches ventrally well below the post- , glenoid process. The presence of a gap between bulla and basioccipital is correlated with the size of the bulla, and occurs among modern Artiodactyla only in the Cervidae and Giraffidae. No such direct explanation can be found, however, for the presence or absence of fusion of the bulla to the pars petrosa of the periotic. The two are independent of each other, as in Merycoidodon, in the Suidae, Hippopotamidae, Camelidae, and Caprinae. In the Suidae alone of these the two bones are in con- tact. They are fused together in the Bovidae and in some Cervidae. The most obvious explanation of these various conditions in living Artiodactyla is the degree of development of the internal carotid artery. In liv- ing Artiodactyla this is present in the late embryo- logical stages but degenerates and becomes small or disappears entirely in the adult. Thus the presence of a gap between bulla and pars petrosa and its size, if present, may depend upon the ontogenetic stage at which the internal carotid disappeared or ceased to function. This is borne out by the fact that in Suidae, where a gap is present, the artery is functional, though greatly reduced. This is also true in Uamelus. One of the chief problems concerning the auditory bulla has been that of its composition. It was first thought to be formed by one bone, the tympanic (more properly ectotympanic). Later it was discovered that another bone, the entotympanic, sometimes participates in the formation of the bulla. This is a neomorp'h in mammals, and ossifies relatively late in ontogeny. As its name indicates, it forms, if present, the medial side of the bulla. More and more instances of the presence of the entotympanic in the wall of the bulla are being brought to light (van Kampen, 1905; van der Klaauw, 1931). It has been the consensus of opinion that in the Artiodactyla (with the very doubtful exception of the \ SHORTER CONTRIBUTIONS TO GENE/EAL GEOLOGY, 1952 Suidae: Parker, 1886) the bulla is composed entirely of the ectotympanic. The composition of the bulla remains largely a matter of opinion, as stated above, because any elements form- ing it are in almost every case completely fused to- gether in the adult stage. In a few, however, a suture is present in the adult, indicating the presence of both ectotympanic and entotympanic. Such a suture was found in the sectioned skull of M erycoz’dodon (fig. 20, T and fig. 21, ET) and in 1 of 12 other Merycoidodtm skulls examined. It thus seems possible that this genus is an exception to the previously accepted rule as to the composition of the bulla in the Artiodactyla. The auditory bulla is bordered by several openings in the skull. Among these is the fissura glaseri (figs. 15 and 21, F 0), through which the chorda tympani branch of the facial nerve passes from the tympanic cavity on its way to anastomose with the mandibular branch of the trigeminal nerve (see Goodrich, 1930, p. 462). Into the inner end of the fissura glaseri projected the pro- cessus folii of the malleus, a remnant of Meckel’s cartilage. , The fissura of Merycoz'dodon is completely sur- rounded by the ectotympanic bone except for a space of about 2 mm on its antero—lateral side where the squamosal participates in its wall. This surface of the squamosal (fig. 21, MF) is known as the margo fissurae. This condition differs from that in living mammals in which the entire lateral wall of the fissura glaseri is formed by the margo fissurae of the squamosal. Between the ventral crest of the external auditory nieatus and the posterior crest of the tympanic bone, which is suturally attached to the paroccipital process, lies the vagina processus hyoidei, the pit in which is lodged the cranial end of the tympanohyal bone. It lies posterior to the inflated part of the bulla, and is separated by a low ridge of the occipital bone from the stylomastoid foramen, which lies posterior and slightly lateral to it (fig. 15, SM; the vagina processus hyoidei is not labelled in this figure). The vagina is seen, in section, to be an excavation in the thick portion of the ectotympanic bone that forms a part of the external auditory meatus (fig. 19, VPH). In the modern Artiodactyla, as in Merycoidodoln, the vagina processus hyoidei is well separated from the stylomastoid foramen. In the living families their swollen bullae grow around the tympanohyal, making the vagina deeper and more conspicuous. In some families this posterior inflation of the bullae is so great that the tympanohyal springs from the side of the bulla instead of behind it (Tragulidae, Bovidae). The inflated bullae may entirely surround the tympanohyal, forming a pit. This is true of the Tragulidae, Giraf- fidae, Camelidae, and some of the Bovidae. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA The stylomastoid foramen (figs. 15 and 19, F SM ) lies just posterior to the vagina processus hyoidei. It opens ‘ into the extreme posterior end of the tympanic cavity, separated from the foramen lacerum posterius by the paroccipital process. Merycoidodon thus resembles the living Ruminantia and the early Tertiary buno- donts (presumably Non-Ruminantia) (Colbert, 1938). It differs from the living Non—Ruminantia, in which the stylomastoid foranien is confluent with the fora- men lacerum posterius. The facial nerve leaves the tympanic cavity through the inner opening of the stylomastoid canal. This is the foramen stylomastoideum primitivum. Here the chorda tympani leaves the facial nerve and goes forward into the tympanic cavity. EXTERNAL AUDITORY MEATUS This bony tube (fig. 14, MAE ; fig. 15) , which connects the middle ear with the exterior of the skull, has already been discussed in part under the consideration of the squamosal bone, which forms its dorsal, posterior and part of its ventral wall. The remainder of the meatus is formed by the ecto- tympanic bone; in other words, it is a direct lateral extension of the auditory bulla. The meatus is much more heavily ossified than the bulla. Its course from the exterior is inward and slightly downward for most of its length. At the medial border of the postglenoid process, it turns slightly anteriorly and enters the bulla. At its entrance into the bulla, the ectotympanic wall of the meatus projects about 5 min. into the tympanic cavity (fig. 20, OT). This projection is called the crista tympanica of the meatus (Bondy, 1907; Simpson, 1936). The tympanic cavity extends laterally both anterior and posterior to the crista; such an extension is known as a recessus meatus. This is also present in all living Artiodactyla. The medial termination of the external auditory meatus is an almost complete ring (it is open for a few millimeters dorsally) upon which was stretched the tympanic membrane (fig. 20, OT). This semi-ring represents the earliest point of ossification of the ecto- tympanic. The dorsal gap in the tympanic ring is filled by the margo tympanici of the squamosal, a medi- ally projecting process of the superficies meatus, which forms the dorsal wall of the external auditory meatus (fig. 20, MTS, SIMS). This is in contrast with most living genera of Ruminantia and also with Hippopota- mus (van Kampen, 1905, p. 592). In these genera, the entire external auditory meatus is formed by the tym- panic bone. To the margo tyinpanici was attached the dorsal edge of the tympanic membrane. The orientation of the external auditory meatus 135 (pointing backward and slightly upward) agrees with that of the Ruminantia and differs sharply from that of the Non-Ruminantia. PARS MASTOIDEA OF THE PERIOTIC BONE This is the posterior part of the ossification of the otic capsule, and is distinguished by its cancellous structure from the pars petrosa, which is rock-like in its density. The pars mastoidea is exposed on the occipital sur— face of the skull as a plate of bone (M, fig. 14) lateral to the occipital bone and medial to the lambdoid crest. This plate terminates ventrally between the posttym— panic and paroccipital processes as the very small mas- toid process, quite insignificant as an area of muscle attachment. Medially, this process is in contact with the paroccipital process. Sections show that the mastoid process is in contact with the posttympanic process not only posteriorly, but also medially. A small flange (M, fig. 19) projects anteriorly from the mastoid, between the posttympanic process and the pars petrosa, and forms part of the lateral wall of the stylomastoid foramen. Because the pars mastoidea is exposed at the surface of the skull, Merycoidodon is one of the “mastoid Artic— dactyla,” one of the two divisions of the order sug— gested by Helga Pearson (1927). In the other division, the “amastoid Artiodactyla,” the pars mastoidea is cov— ered by a flange of the squamosal, which overlaps upon the occipital plate. Miss Pearson limits her two groups as follows (1927, p. 458) : Choeropotamus, chochroerus, Hippopotamus, the Anthraco- theriidae, Mimtotherium, Entelodon, and the Suidae appear to belong to one group of Artiodactyla, while the Dichobunidae, Dacm/therium, the Anoplotheriidae, Tapirulus, Amphimeryw, the Cainotheriidae, together with the remaining post-Eocene fami- lies, form another. These may conveniently be termed the “amastoid” and the “mastoid" Artiodactyla respectively. In most living Ruminantia, as in Merycoidodon, the pars mastoidea is well exposed upon the occipital sur- face. However, in the Giraflidae and the Camelidae, the posttympanic process touches the paroccipital process, and covers the ventral surface of the pars mastoidea. ‘ ’ For the purpose of comparison with Merycoidodon, the mastoid regions of a series of Merycoidodontidae were examined at the American Museum of Natural History through the courtesy of Dr. C. Bertrand Schultz and Mr. Charles H. Falkenbach. This series of skulls, culminating with the genus Brachycms,,of late Miocene and Pliocene time, exhibits a progressive tendency of the external auditory meatus to migrate upward and backward between the squamosal and the 136 FS NC ,,,,,,,,—.;;;2////////////'///// /////§///77/I/////////// / %/ ‘ p I SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 ,,,,/////////,.: .. 5 INCHES FIGURE 24.—Merycoidodon culbertsonii, same as figure 14, but with nasal cavity and pneumatic sinuses outlined. X 1/2. Parallel lines slanting to right : nasal cavity. Parallel lines slanting to left : pneumatic sinuses. FS, frontal sinus. exoccipital. These two bones in Brachycms show the beginning of a tendency to grow over the auditory tube; the continuation of this trend, had the Merycoidodon- tidae survived beyond the Pliocene epoch, would have resulted in the amastoid condition typical of the non- Ruminantia. ‘ Thus we see, within one well-defined family, an al— most complete transition from one to the other of Miss Pearson’s two artiodactyl types. The possibility of such a transition is suggested by Miss Pearson in her statement ( 1927 , p. 459) that the mastoid Artiodactyla show a tendency toward reduction of the size of the pars mastoidea. These observations prove that the mastoid condi- tion is a primitive one relative to the amastoid. All Artiodactyla are evolving more or less in the direction of the amastoid condition; the Non~Ruminantia at- tained it in Eocene time, the Merycoidodontidae ap- proached it in Pliocene time. The Ruminantia, however, show at present only a slight tendency toward it. The chief difference, then, between the mastoid and amastoid Artiodactyla is in the relative speed with which the mastoid region is evolving. PNEUMATIC SINUSES These sinuses have been described individually under the discussion of the bones that contain them. Here they will be discussed as a system, and compared with the systems of other Artiodactyla. The pneumatic sinus system of Merycoz'dodo’n is shown in figure 24. It consists of three sinuses, each opening directly into the nasal cavity (1V 0 ). The sphenopalatine sinus (SP8) projects the farthest posteriorly of the three. It is a long, narrow sinus whose posterior end is contained in the presphenoid bone and whose anterior part is surrounded by the pala- MS, maxillary sinus. NC, nasal cavity. SP8, sphenopalatine sinus. tine and the orbitosphenoid. It extends posteriorly below the anterior part of the cerebrum. _ The development of the sphenopalatine sinus as seen here is typical of large mammals. In the smaller ones the development of the orbits and braincase, which are very large in proportion to their skull size, have re- stricted the growth of the presphenoid bone. Thus the sphenoid portion of the sphenopalatine sinus is reduced or absent. The frontal sinus (F8) terminates posteriorly in the frontal bone. It is the only pneumatic sinus contained in the roofing bones of the skull. The maxillary sinus is the largest of the three, and is most widely open into the nasal cavity. Its posterior termination is a blind end in the zygomatic process of the maxilla. The extent of the pneumatic sinus system is to a large degree determined by skull size. The raison d’étre of the pneumatic sinuses seems to be to efi'ect an adjust- ment between the space necessary to house the soft parts within the skull and the external area necessary for muscle attachment, lodgment of the teeth, etc. The larger the skull, the greater is likely to be the disparity between the space thus required within and outside the skull. Among the Artiodactyla, the sinus system of Mary coidodon most closely resembles that of 00138; the skulls of M. culbertsoniz‘ and of 0. am’es are about the same size. The chief difference is that Ovis lacks the spheno— palatine sinus, which is well developed in Men/coi- dodon. Also, the frontal sinus in 0m}; is larger and, unlike that of Merycoz'dodon, communicates around the orbit with the maxillary sinus. The small size of the cerebrum in Merycoidodon explains the presence and size of the sphenopalatine sinus; except for this, the sinus system of the genus f CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA is less extensive than in most modern Artiodactyla of comparable size. This is the more astonishing when one considers that the small brain is surrounded by a great thickness of parietal and squamosal bone that might be expected to be pneumatized, as it is in the Suidae which have a parietal pneumatic sinus extend- ing ventrally into the squamosal and thence into the zygomatic arch. . The Suidae also possess a well developed sinus in the horizontal plate of the maxilla (see Dictyles, fig. 18), which is absent in M erg/00601003012. Of the Ruminantia, only the Cervidae, Tragulidae, and Camelidae have a less extensive pneumatic sinus system than Merycoidodon (Aubert, 1929). The first two of these families possess only a maxillary sinus; the last, frontal and sphenopalatine sinuses but no maxillary. The sinus system of Merycoidodon is not a highly evolved one; the sinuses connect only with the nasal cavity, and have no connections with each other (com- pare the extremely complicated systems of the Giraf- fidae and of most Bovidae; Paulli, 1900). The sinus pattern of M erycoidodon most closely re- sembles that of the Camelidae among the Artiodactyla, and bears least resemblance of all to that of the living Non-Ruminantia. However, the skulls of the latter are highly specialized; and unfortunately the arrange- ment of sinuses in their fossil relatives is unknown. It is probably best to regard the sinus arrangement of Merycoidodon as primitive. It has no peculiarities to indicate the beginning of a trend to any one of the bizarre modifications of the system in late Tertiary Artiodactyla. CIRCULATORY SYSTEM OF THE SKULL In describing the bones of the skull, mention was made of all grooves, foramina, and canals that give evidence of the cranial circulation in Merycoidodon. This circulation will here be compared with that of other artiodactyls, and of various other mammals. ARTERIES The arterial system of Merycoidodo’n appears to have been in all but one respect the same as that of living Artiodactyla, both ruminant and non-ruminant (fig. 17). The difference was in the size and course of the internal carotid artery. This vessel is presentand functional, but very small, in the Suidae (Sisson and Grossman, 1938) and the Camelidae (Lesbre, 1903); in the Tragulidae (Tandler, 1899) the internal carotid is better developed than in all other living ungulates. It is generally absent as a rule in other living Artiod- ‘actyla (Hofmann, 1900), but has been reported in Camus tam/arms, and probably exists in other genera, 238435—53——4 137 as an essentially non-functional vestige (Tandler, 1899, p. 703). The course of the internal carotid artery in M ery— coidodon is very well indicated, and shows the artery to have been a large one (fig. 17, [0A). Undoubtedly it branched from the common carotid artery, as it does in living mammals, and extended dorso—laterally to the base of the skull. There the first evidence of its presence in Merycoidodon is seen. A canal that passes dorso-laterally between the pos- terior extension of the tympanic and the pars petrosa of the periotic is identified as the posterior carotid canal. Its opening to the exterior is through the fora- men lacerum posterius, and it is through this foramen that the internal carotid artery enters the skull (figsf 15—17, FLP) . After entering the foramen lacerum posterius, the internal carotid diverged from the other vessels that passed through the foramen, all of which ran medial, instead of lateral, to the pars petrosa. It then passed through the posterior carotid canal, and turned an— , teriorly into the tympanic cavity. Although the internal carotid can be definitely traced into the tympanic cavity, there is no evidence as to its course through the cavity. Further proof that it crossed this region is, however, furnished by the large antero-medial opening in the bulla, just behind the ostium tympanicum tubae (fig. 15, OTT), which is obviously the anterior carotid foramen. Here the artery left the tympanic cavity, lay for a short distance between the bulla and basisphenoid, and entered the cranium through the foramen lacerum medius (fig. 17, FLM). It lay on the floor of the cranium in a groove (fig. 16) whose size indicates that the internal carotid artery was an important vessel in Merycoidodon. It did not divide to form a rete mirabile, or network of small arteries, but extended undiminished to the chiasma ridge, where it divided into the anterior and middle cerebral arteries. Posterior to the sella turcica, the internal carotid arteries of the two sides were con- nected by the posterior intercarotid artery (fig. 16). There is no groove in the base of the braincase to indicate the presence of an anterior intercarotid artery. A comparison of the basis cranii of Merycoidodon with that of its probable ancestor, Protoreodon of the late Eocene, gives a clue as to the primitive position of the internal carotid artery in the Merycoidodontidae. In Protoreodon (M. C. Z. 5334), the posterior carotid canal opens on the base of the skull through a foramen independent of the foramen lacerum posterius, 3 mm anterior to it on the medial side of the posterior part ‘ ‘ of the bulla. This arrangement is the same as that in the living Lepus (Gregory, 1910, p. 329), the Creo— 138 donta (Matthew, 1910, p. 297), all Carnivora, and some Notoungulata (van der Klaauw, 1931). The an- terior carotid foramen, present in Merycoidodon and in Protoreodon, and situated in the antero—medial wall of the bulla, is also reminiscent of these mammals. In the few modern Artiodactyla that have an internal carotid artery, its path differs considerably from that in Meryooz'dodon, in which it traverses the tympanic cavity. The internal carotid in the non-Ruminantia describes a loop ventral to the auditory bulla, so that the first contact of the artery with the skull is at its entry into the foramen lacerum medius (Sisson and Grossman, 1938; van Kampen, 1905). In the living Camelidae, the internal carotid artery is in a completely closed bony canal whose laterial wall is formed by the medial wall of the bulla, its medial wall by the basioccipital. The internal carotid in the ,Tragulidae also lies along the medial wall of the bulla. In Tragulu‘s it is en- closed in a canal formed entirely by the tympanic bone; in the other genera it simply lies in a shallow groove (van Kampen, 1905). ‘ The above comparison of Merycoidodon with the liv— ing Artiodactyla shows that there are found, within this order, two of the three possible courses of the internal carotid through the tympanic region. The third course, with one branch of the artery passing through the bulla and another lying medial to it, is found only in'the Muridae (van der Klaauw, 1931, p. 180). Within the cranium, the groove for the internal carotid (fig. 16,10A) is evidence for the statement that this artery was much larger than in living Artiodactyla. It also differed from the latter in the absence of a rete mirabile, as has been pointed out by Black (1921) on the basis of his study of natural endocranial casts. Thus the intracranial portion of the internal carotid in Merycoz'dodon resembles that of the Carnivora (see Ellenberger and Baum, 1891, p. 373), but differs from the latter, in the absence of the anterior inter-carotid artery. vnms AND vmrous smusrs The system of vessels draining the blood from the cranium of Merycoidodon (fig. 17) was considerably more complicated than in present-day Artiodactyla, as it contained several additional vessels. As is usual in the Mammalia, an important part in the head drainage in Merycoz'dodon was played by the venous sinuses, which are enclosed by dense membranes and usually lie in bony grooves. They consist of two groups, the dorsal and basilar sinus systems, and their attendant veins. A third venous system is that of the subsphenoid canals of the basisphenoid bone, a venous SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 arrangement here observed for the first time in the Artiodactyla. DORSAL SINUS SYSTEM The vessels of this group lie on the dorsal and dorso- lateral sides of the brain. The most anterior of them is the sagittal sinus, a median vessel lying directly above the longitudinal fissure of the brain and just below the sagittal crest (fig. 22, 88'). Its length, as indicated by the groove it occupied in the roof of the braincase, was 4 mm. No impressions in the braincase indicate the anterior and posterior connections of the sagittal sinus. We may assume, from the anatomy of modern Artiodactyla, that the sagittal sinus of Merycoidodon collected venous blood from the numerous small veins of the surface of the cerebral hemispheres, and transmitted it posteriorly into the transverse sinus, between the cerebrum and cerebellum. Ventro-lateral to the sagittal sinus, on the side walls of the pyriform lobes, lies the vena collateralis cerebri, which is the only connection in Merycbz'dodon between the veins of the face and orbit and the dorsal sinus system. The presence of this vein is indicated by an antero-posterior groove in the side wall of the braincase (fig. 16, V00). The vena collateralis cerebri entered the cranium through the sinus canal (fig. 16, PSO), which carried it from its origin in the orbital venous plexus. The groove for the vena collateralis cerebri extends back- ward as far as the posterior part of the cerebrum where, presumably, it joined the transverse sinus near its entry into the temporal canal. A vein almost identical with that indicated in Mary— coz'dodon is found in many modern Insectivora. Greg- ory (1910, p. 248) reports it in Solenodon, Mio’r‘ogale, and Em'mweus; and Shindo (1915) notes its presence in Talpa europaea. In the last, however, the vena collateralis cerebri enters the cranium through the optic foramen rather than an independent canal. According to Shindo, this vein is a remnant of the anterior cerebral vein of the early embryonic stages. In some living mammals, the back part of the vena collateralis cerebri is present, but the anterior connection with the orbital plexus never develops. See Lepus (Shindo, 1915, p. 370). In the possession of this vein in its entirety, Mery- coidodon difl’ers from all but the most primitive of living mammals. The chief path by Which the venous blood of the dorsal sinus system left the cranial cavity was the temporal canal (see p. 130). The blood passed from the transverse sinus into at least three veins, the supe- CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA. rior cerebral, the vein of the postparietal canal, and the mastoid emissary. The superior cerebral vein entered the temporal canal through a foramen between the pars petrosa and the endocranial surface of the squamosal. This foramen opened into the sinus venosus temporalis (fig. 20, SVT), which lies almost entirely in the squamosal. Besides receiving blood from the superior cerebral vein, this sinus undoubtedly collected it from the tiny veins filling the thick diploé of the squamosal. From the sinus the superior cerebral vein passed ventroposte— riorly into the temporal canal (fig. 20, T0; fig. 21, FJSP), leaving it through the foramen jugulare spurium (figs. 15, 17, T0) to join the external jugular vein (fig. 17, EJV). ' The foramen jugulare spurium is very small con- sidering the size of the sinus venosus temporalis, which it drains but this disparity can be explained. Prob- ably the temporal sinus served chiefly as a reservoir, in other words, the pressure of the blood therein was low. Besides, a posterior branch of the temporal canal (see below) relieved the foramen jugulare spurium of the necessity of transmitting all the blood in the temporal sinus. Although it has not been reported in any living mammals, the sinus venosus temporalis cannot be re- garded as a primitive structure. It is, however, an expression of the small size and correspondingly primi- tive condition of the cerebrum of Mewcoz‘dodon. The temporal canal is present in the Ruminantia, but absent in the N on-Ruminantia. The posterior branch of the temporal canal begins a few millimeters above the foramen jugulare spurium. Thence it extends postero-laterally to its exit from the skull through a foramen between the external auditory meatus and the postglenoid process (fig. 17, PTO). After leaving the skull, this vein also joined the ex- ternal jugular. The vein homologous with this one is the only external orifice of the temporal canal in the modern Artiodactyla and the living Equidae and Carnivora (Dennstedt, 1903). Another vessel that drained the transverse sinus of Merycoidodon was the vein of the post-parietal canal, which extended backward beneath the parieto-squa- mosal suture. Just before its exit from the skull, this vein in some cases divided into two or more small branches. It is represented in Merycoz'dodon by the post-parietal foramina (fig. 14, FPP). This vein is present in many modern mammals, including some Artiodactyla (see above). Some distance ventral to the pvostparietal canal is the passage for another vein, the mastoid emissary. This leads from the temporal canal back to the mastoid fora- 139 men on the occipital surface of the skull. It probably drained posteriorly into the vertebral or the deep cervi- cal vein and thence to the anterior vena cava. The mastoid emissary vein is present in living Ruminantia; it is absent in the Non-Ruminantia, probably because the overlapping of the squamosal bone upon the loc- cipital surface caused a rerouting of the blood by covering the area where the mastoid foramen lay. The dorsal petrosal sinus is the last member of the dorsal sinus system of which traces are found in the skull of Mewooz'dodon. This vessel was, as in living mammals, a tributary of the superior cerebral vein, which it joined at its entrance to the sinus venosus temporalis. The dorsal petrosal sinus gathered venous blood from the lower part of the cerebral hemispheres and, before joining the superior cerebral vein, coursed posteriorly in a groove in the dorsal side of the pars petrosa. Judging from the depth of this groove, the sinus was rather small (fig. 21, DPS). BASILAR SINUS SYSTEM These vessels in Merycoz'dodon, as in modern forms, were much more closely connected with the antero- posterior drainage of the head than was the dorsal system. There is no evidence that the two systems were connected in any direct manner. The basilar sinus system, judging from the condition in living mammals, received blood from the nasal cavity and maxillary region by way of the orbital venous plexus. From this plexus a large vein extended back- ward through the foramen lacerum anterius (fig. 15, FLA). Within the cranium it entered the cavernous sinus, which lay posteriorly in a groove on the cranial floor (fig. 16, [0A). Behind the pituitary fossa (fig. 16, PF), the cavern- ous sinuses of both sides were connected by the posterior intercavernous sinus. In this respect Merycoz'dodon differs from Sus (Dennstedt, 1903) which has no poste— rior intercavernous sinus. Meryooidodon had no anterior intercavernous sinus. In this it differs from 808 but resembles the Caprinae (Dennstedt, 1903). The cavernous sinus debouched from the braincase through the foramen lacerum medius (fig. 15, FLA/I). Here it was continuous posteriorly with the inferior petrosal sinus, a large vessel that was contained in a groove formed dorsally by the pars petrosa and medi— ally by the basioccipital bone. This groove is the petro- basilar canal (figs. 14, 16, P30). The internal carotid artery of Merycoidodon passed lateral to the pars petrosa, and the inferior petrosal sinus ventro-medial to it (fig. 17). As well as could be determined from study of the skull of Camelus (for 140 the literature isivague on this point) these two vessels in that genus run side by side in the petrobasilar canal. This is also true of the living Perissodactyla (Sisson and Grossman, 1938). In the posterior third of its course (fig. 15) the petro- basilar groove in Merycoidodon lies medial to the pars petrosa, and is impressed in the basioccipital only. Be- yond this groove, the extracranial part of the inferior petrosal sinus probably emptied into the inferior cere- bral vein, and thence to the internal jugular (fig. 17). The serial sections revealed a minute canal extending posteriorly in the backward extension of the alisphenoid bone above the auditory bulla (fig. 21‘, VOL?). This canal probably carried a vestigial vein, so small as to be non-functional, which branched from the cavernous sinus at the foramen lacerum medius and passed into the dorsal side of the tympanic cavity. This course suggests that it may be a remnant of the embryonic lateral head vein: it runs medial (although posterior) to the alisphenoid bone, which is the homologue of the lamina ascendens of the embryonic ala temporalis. ,The ala temporalis, in turn, is homologised by Broom (1907) with the reptilian epipterygoid. Furthermore, the position of this small vein dorsal to the auditory ossicles is equivalent to a location dorsal to the jaw articulation of the Reptilia, where the lateral head vein lay. To return to the functional portion of the basilar sinus system, we find that the inferior petrosal sinus, slightly anterior to the beginning of its extracranial portion, emitted a branch, the condyloid vein, which continued posteriorly within the skull in a groove at the lateral side of the myelencephalic base. It found its exit from the skull through the condylar foramen (figs. 15, 16, 0F; fig. 17 0V) and joined the occipital vein, which probably transmitted the blood to the deep cervi— cal or the vertebral vein. This constituted the second of the two outlets of the basilar sinus system. SUBSPHENOID VEINS AND THE SINUS VENOSUS OSSIS SPEENOIDALIS The evidence for the presence of this most unusual set of veins, hitherto unrecorded in Artiodactyla or in most other mammalian orders, consists of the well- developed canals by means of which they passed through the basisphenoid bone of Merycoidodon (see p. 122, and fig. 17). A survey of anatomical literature proves beyond a doubt that the cavity in the basisphenoid bone (fig. 17 , SVOS) contained a venous sinus, and that the canals leading from it to the surface of the skull (fig. 17, 830) conveyed blood into it from the orbital region and out of it posteriorly. Such a venous cavity in the basisphenoid was first SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 reported by W. Krause (1868; cited by Arai, 1907), who observed it in the human foetus and in 10 percent of new-born infants studied. Arai (1907) found the same structure in the adult Lepus cum'oulus, and named it the-sinus venosus ossis sphenoidalis (this rather cum- bersome title is necessary to differentiate it from the sphenoidal pneumatic sinus). In Lepus, the upper wall of this sinus is open into the pituitary fossa, and the membranous wall of the venous sinus is in contact with the dura mater which surrounds the pituitary body. In Lepus, the venous sinus receives blood from the veins of the dura mater. In Merycoz'dodon there is no such connection between the sphenoidal venous sinus and the pituitary fossa. This venous sinus has been regarded by most anatomists (Arai, 1907; Wal- deyer, 1907 ; Bovero, 1905) as a remnant of Rathke’s pocket. Voit (1909), however, feelsthat it is too far posterior and must be a secondary structure. As the sinus is found in the embryos of many mammals that lack it in the adult stage, the first hypothesis seems the more likely. . As in Merycoidodon, Lepus has one or more canals leading into‘the sphenoidal venous sinus from the ex- terior of the basisphenoid bone. These are designated by Arai (1907 ) the foramina venosa but, since they are the openings of what he calls the subsphenoid canals, they are here given the more specific title of sub— sphenoid foramina. A functional sphenoidal venous sinus with its asso— ciated subsphenoid canals is found in the adult stage in relatively few mammals. These are the Sciuromorpha and Myomorpha (Bovero, 1905), the Marsupialia (Gregory, 1910, p. 431) and the Lagomorpha (Arai, 1907). The manner of circulation of the venous blood of the head in the above-mentioned groups indicates the part which the sphenoidal venous sinus of M erycoz'do- don played in its cranial circulation. Anteriorly the subsphenoid canal must have re- ceived, as in these groups, a branch of. the ophthalmic vein coming from the orbital plexus. Posteriorly, the vein passed out through a foramen in the anterior wall of the foramen lacerum medius (fig. 16, FSP) . Thence ' the blood undoubtedly flowed into the posterior portion of the cavernous sinus, just anterior to the confluence of the latter with the inferior petrosal sinus. It is apparent from the skulls of Merycoidodon which were dissected that the vessels of the sphenoidal sinus system were larger than the cavernous sinus and, there- fore, that the sphenoidal vessels were among the most important paths by which the blood of the facial region in Merycoz'dodon was drained posteriorly. We have no way, of course, of knowing the size in this genus of ,CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA the external maxillary vein, which is the chief pos— ' teriorly directed vein leaving the facial region of living Artiodactyla. I The facts here set forth show that, despite the size of the temporal canal, the preponderant venous outlet of the skull of Merycoidodon was the internal jugular vein rather than the external jugular as in modern Artiodactyla (Bolk, Goppert etc., 1936). This fact is proved by the large size of the sinus venosus ossis sphenoidalis and of the inferior petrosal sinus, and by the small size of the opening of the temporal canal, which led to the external jugular vein (fig. 17). The internal jugular, a remnant of the lateral head vein, is the more primitive means of drainage. In this respect, 00138 and 803 are mammals of the most ad- vanced type. In these genera, the external jugular vein drains the skull, and the last vestige of the lateral head vein is lost. In Merycoidodon, a large part of the blood from the face must have run posteriorly through the subsphenoid canals. In the more advanced Artiodactyla, the me- chanical advantages of an extracranial route appar- ently prevailed; the subsphenoid canals degenerated, and the external maxillary vein carried the blood which they had once transmitted. This change in circulation took place much earlier in evolution than the equivalent one in the arterial system. NERVES OF THE SKULL REGION The nerves supplying the cranium of Merycoz'dodon, as described above from grooves and foramina in the skull bones, do not differ in any important character- istics from those of living Artiodactyla. CRANIAL MORPHOLOGY 0F POEBROTHERIUM Poebrotheriwm is the genus which represented, in White River (Oligocene) time, the ancestral line lead- ing to the modern camels and llamas. Like the other 141 extinct camel-like mammals, it is included with the living genera in the suborder Tylopoda. For this study, serial frontal sections were made of a skull of Poebrothem'um we'lsoml Leidy, from Oligocene rocks exposed near James Creek, in the Hat Creek Basin, Sioux County, Nebraska. It was collected in 1922 by a party from the Walker Museum, University of Chicago. Study of the serial sections was aided by comparison with four other skulls. of P. wélsom', and with one of P. emimium Hay, a larger species. N0 skulls of P. labiatum Cope, the only other species of the genus, were available for study; but reference has been made to descriptions and plates of the skull of this species (Scott, 1891, 1940). The anatomy of the skull of Poebrotherium will not be described here in as great detail as was that of M ery- coidodon; it will suffice to point out some significant similarities and differences between the two, especially those made available for the first time by the use of serial sections. BONES OF THE SKULL ' As in Merycoidodon, the basioccipital, exoccipitals and supraoccipital are fused in Poebrothem'um into an occipital bone (fig. 25, 00). The paroccipital process of this bone (fig. 25, PPO) is suturally attached for its entire length to the auditory bulla. This is due chiefly to the great inflation of the latter. Another result of this inflation is that the basioccipital is in contact with the medial wall of the bulla (fig. 26), there being no gap between them as in Merycoz‘dodon. Within the braincase, the course of the condyloid vein is indicated by an antero-posterior groove near the lateral edge of the basioccipital. This is present also in Merycoz'dodon. The most striking characteristic of the basisphenoid bone (fig. 26, BS) is that, as in Mewte/coidodon, it con- tains a large sinus venosus ossis sphenoidalis, with its 2 INCHES FIGURE 25.——Poebrotherium wilsom’. FSM, stylomastold foramen. OC', occipital bone. PA parietal bone. PM, pars mastoldea of periotic bone. Lateral view of skull. Modified after w. B. scan. >< I/g. PPO, paroccipital process of exoccipltal. so, squamosal bone. TEAM, expanded external auditory meatus. TY, tympanic bone. 142 FIGURE 26.—Pocbrotherium u'ilsom‘, ventral View of basis cranii. Com- posllie, drawn from Princeton Museum no. 12692 and M. C. Z. 5998, X 2- B, auditory bulla. BO, basiocciptal bone. BS, basisphenoid bone. 0F, condylar foramen. FLM, foramen lacerum medius. ELP, fox-amen lacerum poster-ins. F0, foramen ovale. FSA, anterior subsphenoid foramen. FSM, stylomastoid foramen. G, groove separating bulla from external auditory meatus. GS, glenoid surface of squamosal bone. IM, inflated part of external auditory meatus. MAE, external auditory meatus. PPO, paroccipital process of exoccipital. tributary subsphenoid canals (fig. 28, SVOS ; cf. fig. 26, FSA). The sphenoidal venous sinus is larger than in Merycoz'dodon because of the greater dorso-ventral dimension of the basisphenoid. The sinus becomes 'narrower anteriorly, where the portions of the basi- sphenoid lateral to the sinus are filled with large—celled cancellous tissue. The sphenoidal venous sinus termi- nates anteriorly below the anterior end of the pituitary fossa; this differs from the condition in Merycoidodon, in which the anterior end of the sinus lies below the- posterior end of the fossa. Within the cranial cavity, the basisphenoid is exca- vated by the pituitary fossa, which is shallow, as in Merycoidodon and the living T ylopoda (Lesbre, 1903). The anterior end of the fossa is marked by an eminence which rises about 2 mm. above the floor of the braincase. At its posterior end are the posterior clinoid processes, whose bases are about 3 mm. apart. They are very delicate, and arch toward each other, almost touching at the midline of the skull. Along either side of the pituitary fossa lie the grooves for the cavernous sinus and internal carotid artery and, lateral to these, the grooves for cranial nerves III, IV, VI, and the first two branches of nerve V. These path— ways are separated by a very low ridge. Lateral to the groove which carries the cranial nerves is a higher, sharp ridge. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 The alisphenoid bone of Poebrothem’um differs from that of Merycoz’dodon in that it lacks a posteriorly projecting plate above the ostium tympanicum tubae. This function is taken over by the squamosal (see be- low). The posterior portion of the alisphenoid is in sutural contact with this horizontal plate of the squa- mosal, but does not reach backward as far as the ostium. Within the cranium, a few millimeters medial t0 the alisphenoid-squamosal suture, a deep groove runs ante- riorly from the region of the foramen lacerum medius to the foramen ovale (fig. 26, F 0 ,' hidden by the audi- tory bulla). Judging from its course, this must have borne the third (mandibular) branch of cranial nerve V. The alisphenoid of Poebrotherium further differs from that of Merycoid'odon in that the cavity for the sinus venosus ossis sphenoidalis extends laterally into it, as in the living Leporidae (Arai, 1907). The deep, narrow presphenoid bone is of nearly the same shape as that of Merycoidodon. It is filled with cancellous tissue of much finer texture than that present elsewhere in the Poebrothem'um skull. At its anterior end the presphenoid is no narrower than in Merycoidodon, but, in contrast to this genus, it contains no pneumatic sinus. On the external surface of the skull of Poebrother- ium, the orbitosphenoid bone is in about the same posi- tion as in Merycoz'dodon. Within the cranium it shows an interesting difference in that its posterior root proj- ects inward beneath the cerebrum as a curved, dorsally . convex plate roofing the cranial nerves (IV, V1, V2, VI), which lay in a groove lateral to the pituitary fossa. In the anterior part of their intracranial course, therefore, these nerves were surrounded on all but the medial side by bone (fig. 28, FLA). This plate of the orbitosphe— noid is probably a secondary ossification rather than a homologue of the lateral lamina of the sella turcica in Merycoz'dodon. Where it forms part of the anterolateral wall of the \ cerebrum, the orbitosphenoid reaches its maximum . thickness of 5 mm. This is the thickest part of the braincase wall, which as a Whole is distinguished from that of M eryc‘oz'dodon by its light construction. The thickened portion of the orbitosphenoid is solidly ossi- fied, in contrast to the other bones of the Poebrothem'wm skull, which tend to be filled with large—celled cancel- lous tissue. In the skull of Poebrothem'um which was serially sec- tioned, almost no trace remained of the ethmoid bone. A small fragment of the bony nasal septum appears approximately in place in one section; it is only 1 mm thick. The only evidence concerning the characteristics of CRANIAL MORPHOLOGY OF SOME OLIGOCEN'E ARTIODACTYLA the turbinals is a sharp ridge projecting ventrally into the nasal cavity from each nasal bone. These projec— tions run the entire length of the nasals, which are very long in this genus; they undoubtedly served as roots for the naso-turbinal bone or cartilage. It may be in- ferred, then, that these scrolls at least were well de- veloped in Poebrothem’um. Similar ridges are present in the living Camelws. They support a cartilaginous nasoturbinal scroll. The nasal septum and turbinal scrolls were probably much less heavily ossified in Poebrothem‘um than in Merycoz'dodon. The vomer was missing in the sectioned skull of Poebroflwm’um. There is no separate ossification of the preinterpa- rietal or interparietal in this skull. The parietal bones are very long, and form almost the entire roof of the braincase. Posteriorly, the pa- rietals conform much more closely to the shape of the brain (fig. 27) than do those of Merycoz'dodon. The vermis cerebelli of Poebrofherz'um was higher than that of Merycoidodo’n, projecting above the dorsal plane of the cerebrum, and very narrow. Its sides were nearly FM SF TC SM RE 9’ SH ,;/> - BO £7427 ’ //‘ , / FIGURE 27.—P0(’br01ht’rium wilsoni Leidy. B, bulla. BO. basioccipital. FM, foramen magnum. I00 internal carotid canal. IT, incisura tympanica, PAR, parietal. PET. pars petrosa. RE, recessus epitympauicus. 143 vertical. These observations agree with the deductions drawn by Bruce (1883) and Scott (1940) on the basis of studies of damaged natural endocranial casts. The posterior portions of the parietals are filled with diploe for about 10 mm on either side of the sagittal crest (fig. 27). The diploic layer is thin, however, and in this region the maximum thickness of the parietals is only 5 mm. Over the junction of the cerebrum and cerebellum, the parietals become thicker, and their diploic cells increase in size to an average diameter of 2 mm. Here the diploé spreads farther laterally than over the cere- bellum, extending about 18 mm ventrolaterally from the sagittal crest. At their anterior termination, the parietals are again simple bony plates, devoid of cancellous tissue. This is true also of the posterior part of the frontal bone, dorsal to the anterior part of the cerebrum, which has an average thickness of only 2 mm. The descending plate of the frontal, which forms part of the side wall of the braincase, is heavier than the dorsal plate and, in its posterior portion, consists of solid non-diploic bone like that of the orbito- PAR 7"... 52 . Thick section of skull, prepared from sections P 1~17. viewed posteriorly from level of vagina processus hyoidei. Natural size. SF, subarcuate fossa. SH, hypotympanlc sinus. SM, superficies meatus, SQ, squamosal. SVT, sinus venosus temporalis. TC, temporal canal. TH, tympanohyal. 144 sphenoid, Which adjoins it. Farther anteriorly the large diploic cells of the supraorbital process are con— tinued ventrally into the lateral wall of the olfactory bulbs. The supraorbital process of the frontal is very thick dorsoventrally, in marked contrast to the brain—case portion of the same bone. It is filled with large-celled dipolic tissue. Between these processes, and dorsal to the anterior moiety of the olfactory bulbs, the hori- zontal plate of the frontal reaches its greatest thickness (5 mm). and is entirely cancellous in structure. The olfactory lobes are somewhat larger than those of Merycoidodon, which has so often been cited as an extremely macrosmatic genus. Comparison of the olfactory lobes of Poebrothem’um with those of the living Camelus (Lesbre, 1903) indi- cates that, even considering the greater size of the neo- pallium of Camelus, the lobes of smell in Poebrotherium are nearly twice as large for the size of the brain. The squamosal bone of Poebrotherium differs from that of M erycoidodon in that it is diploic only along its base (medial to the temporal crest and, farther for- ward, to the root of the zygoma). Above this the greater portion of the squamosal plate is very thin and conforms closely' to the shape of the cerebrum (fig. 27). This bone is relatively much thicker in living Tylopoda. The horizontal ventral plate of the squamosal is even more intimately involved in the structure of the middle ear in Poebmthem‘wm, than in Men/coidodo'n. The term “horizontal plate” is not applicable here in a strict sense, for parts of this structure are at a sharp angle with the horizontal. A part of the ventral squamosal plate, the superficies meatus (fig. 27, SM) forms the roof of the external auditory meatus. It is a very thin plate of bone, lying in an almost vertical attitude due to the steep slant of the tube of the meatus. In Merycoidodon the su- perficies meatus is horizontal and about three times as thick as in Poebrotkefim. The superficies meatus extends ventromedially into the tympanic cavity, terminating 2 mm lateral to the promontorium, and dividing the front part of the tym- panic cavity into dorsal and ventral cavities. In the living Tylopoda, there is no such medially projecting plate of the superficies meatus (van Kampen, 1905). In Merycoidodon it projects medially in a hori- zontal direction and its medial end is in contact with the pars petrosa above the tympanic cavity. A more truly horizontal part of the ventral plate of the squamosal is that which projects medially above the ostium tympanicum tubae. To its ventral side, lateral to the ostium, is attached the anterior part of the auditory bulla. Over the anterior end of the SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 ostium, the squamosal plate meets the alisphenoid, and also extends behind it, where a gap between the squa- mosal and the basioccipital forms the foramen lacerum medius. The squamosal therefore plays the part in Poebro- them'um which, in Merycoz'dodon, is taken by the pos- teriorly projecting plate of the alisphenoid, which partially roofs the tympanic cavity. The temporal canal, bearing the superior cerebral vein, is not contained, as in Merycoz’dodon, entirely within the squamosal, but is bounded only dorso- laterally by it (fig. 27, T0). This canal is further discussed below. Like Merycoidodon, Poebrothem'wm possessed an anterior branch of the temporal canal; it ran entirely within the squamosal, however, and not between the squamosal and the tympanic. The vein which occupied this canal reached the surface just medial to the root of the zygoma through two foramina, the supraglenoid foramina of Cope (1880). Examination of other skulls of the genus reveals that either one or two supraglenoid foramina may be present and that the number may differ on the two sides of the same skull. The same is true of the living Tylopoda. No supraglenoid foramen is present in Merycoz'dodon. Poebrothem'wm possesses a maxillary pneumatic sinus along the medial side of the cheek-tooth row and dorsal to it, and projecting posterior to the third molar into the tuber maxillare (fig. 28). The sinus is almost square in frontal section, with a height of about 15 mm. Anteriorly it reaches as far as the fourth premolar, a distance of about 33 mm. The maxillary sinus ascends into the vertical plate of the maxilla, ventral to the lacrimal fossa. Probably the entrance of this sinus into the nasal cavity lay in the medial wall of this ex- tension; this could not be definitely determined, how- ever, because of the broken condition of the bone in this area. The ventrally projecting vertical plate of the pala- tine bone is much heavier than in Mewcoz'dodon. It is directed ventro-laterally and is in contact medially with the pterygoid bone, a slimmer plate that is oriented vertically. This union of the two bones forms a bifur- cated process such as is also typical of living Tlepoda (fig. 28, PAL, PT). TYMPANIC REGION PARS PETROSA OF THE PERIOTIC BONE An interesting feature of this bone in Poebrotherium is the extremely large subarcuate fossa that occupies its entire dorsal side. The front part of the fossa (fig. 27, SF) is a simple depression in the pars petrosa, such as was observed in Merycoz'dodon, but behind this it is a cavity whose floor is the dorsal side of the pars vestib- CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA 145 FR OL OF 80 AS SVOS MS MX FIGURE 28. —Poebratherium wilsom Leidy. Thick section of skull, prepared from sections P 37—81, viewed anteriorly into olfactory lobes. AS, alisphenoid. BS, baslsphenoid. FLA, foramen lacerum anterius. FR, frontal. Ms maxillary sinus. M , maxilla. M 3, third molar. 0F, optic foramen. ularis, and Whose side walls and roof are formed by the bony arch which housed the posterior semicircular canal (fig. 27, F). Its posterior wall is a part of the dorsal portion of the pars mastoidea of the periotic. This fossa was the receptacle of the lobulus petrosus of the cerebellum, mentioned above in the discussion of Merycoidodon; the lobulus of Poebrothem'wm must have been at least three times this size. The modern Lagomorpha have an identical fossa. Krause (1884, p. 182) described it, and designated it the fossa mastoidea. A very similar structure is reported by Elliot Smith (1903, p. 428) to exist in all Primates except Simia, Anthropopz'thecus and Homo. For comparison with modern descendants of Poe- brotherium, the writer examined the skulls of Tylopoda in the osteological collection of the Museum of Com- parative Zoology at Harvard University. The roof of the ‘braincase had been removed from only two skulls, specimens of Lama hmachus (M. C. Z. 1746, M. 0. Z. 29878); and in both skulls the fossa mastoidea was identical With that of Poebrothem'mm No mention of this fossa has been made in the literature but it seems safe to conclude that it is typical of modern Tylopoda. Skull somewhat distorted. Natural size. 0L, olfactor lobes. OS, orbitosp enoid PAL palatme. PT, pterygold. SO, sinus canal. SQ, squamosal. S50, subsphenold canal SVOS sinus venosus ossis sphenoidalis. Further examination of skulls of present-day Artic- dactyla reveals that no others possess the fossa mas— toidea. Its presence in the living Tylopoda contradicts the statement of Black (1921, p. 310) and Bolk (1906) that no modern ungulates possess the lobulus petrosus of the cerebellum. MIDDLE EAR AND SURROUNDING STRUCTURES The auditory bulla of Paebrothem'um (fig. 26, B) is typical of Tylopoda—extremely large and filled with cancellous bone. The relationships of the bulla to its surrounding structures differ from those of Merycoz'dodon largely because of its greater size, and agree correspondingly with those of the living Tylopoda. The bulla projects posteriorly along the lateral side of the paroccipital process, to which it is attached. Ven- trally, it overlaps the anterior part of the process. Dorsally, the main part of the bulla is in contact with the pars petrosa and the squamosal. It projects much farther anteriorly than in most mammals. The an- terior part of the bulla in Poebrothem’wm, is well inflated and entirely cancellous; it is laterally compressed to- 146 ward its dorsal side, and serial sections show its dorsal margin to be in contact with the suture between the alisphenoid and squamosal. ‘ As in the living Tylopoda, the bulla (of Poebroth— erz'mn is in contact medially with the pars petrosa but is not fused with it (fig. 27, PET, B). No gap exists between the two as in Mer‘ycoz'dodon. Despite the great size of the Poebrotherium bulla., the hypotympanic sinus is no larger than that of ilery- coidodon (fig. 27, SH). It is of relatively the same size and shape as that of Lam and Oa/melus (van Kampen,‘1905, p. 594). The ostium tympanicum tubae is longer than that of Merycoz'dodon, because of the greater anterior ex- tension of the bulla. It is closed below by the contact of the bulla With the basisphenoid, and above by the horizontal plate of the squamosal bone. The living Tylopoda differ from Poebrotkeréum in that the ostium tympanicum tubae is roofed by the alisphenoid (van Kampen, 1905) as in Merycoidodon. In Poebrothem'um, the tympanic bone forms almost all of the medial wall in addition to the ventral and part of the lateral wall of the tympanic cavity. The pars petrosa is thus limited almost entirely to the roof of the cavity (fig. 14). The cavity is Wider and shallower than that of Merycoz'dodon. The epitympanic recess of Poebrothemium, instead of lying directly above the tympanic cavity as in Mery- ooidodovn and Camel/us (van Kampen, 1905), extends dorsolaterally above the external auditory meatus. It is very small, and is bounded laterally by the tympanic and squamosal, and dorso-medially by the pars petrosa of the periotic (fig. 27, BE). Just behind the epitympanic recess and also dorso- medial to the external auditory meatus, lies the incisura t-ympanica (fig. 27, I T). As in other mammals, both its dorsal and ventral sides are formed by the squa- mosal bone; it is much larger than in most mammals, however. Comparison of the, diameter of the medial end of the external auditory meatus with that of the incisura, reveals that, in Poebrothem'wm, the pars tensa of the tympanic membrane was very small, and the pars flaccida very large. The incisura tympanica is absent in the living Tylopoda (van Kampen, 1905). The vagina processus hyoidei is almost completely surrounded by the auditory bulla. In the vagina, sec- tions show the tympanohyal (fig. 27, TH) which, as Scott (1940, p. 621) suggested, is not fused to the tym- panic. This fusion is present in the adult modern Tylopoda (van Kampen, 1905, p. 598), in which the bulla completely encloses the vagina to form a true pit. The stylomastoid foramen of Poebrothem'um is the lateral opening of a nearly horizontal canal leading SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 from the tympanic cavity to the posterolateral side of the bulla (fig. 26, F8111). Dorsally, this canal is bounded by the squamosal; it differs from the stylomas- toid canal in Merycoidodon in that its ventral wall is formed by the laterally swollen bulla rather than by the paroccipital process of the exoccipital. The canal in Camelus is formed in the same way. EXTERNAL AUDITORY MEATUS At first glance the porus acusticus externus of P06- brotlzerium appears to open directly out of the tympanic bulla, with no intervening tubular meatus (fig. 26, MAE), but what appears to be the lateral portion of the auditory bulla is actually the inflated meatus (fig. 13, 1M) . The external auditory meatus in Poebrothem'um is surrounded anteriorly, ventrally, and posteriorly by the inflated tympanic bone, and dorsally by the superficies meatus of the squamosal, but in living Tylopoda, the meatus roof is formed by a thin plate of the tympanic, so that the meatus is a tube formed by this one bone. In both Poebrothem'um and its living relatives the tube of the meatus slants sharply dorsolaterally from the tympanic cavity. PARS MASTOIDEA OFVTHE PERIOTIC BONE This bone is well exposed upon the lateral surface of the skull (fig. 25, PM), the exposed area being larger than in Illerycoidodon. In Poebrothem’um, the pars mastoidea is bounded anteroventrally by the tympanic portion of the auditory bulla, rather than by the squa- mosal, which in Merycoidodon overlaps its lower part (figs. 14, 25). In Camelus also (van Kampen, 1905) the squamosal covers the ventral part of the mastoid exposure. This appears to be another instance, like that cited above in the family Merycoidodontidae, of progressive covering, in the course of evolution of a group, of the pars mastoidea by neighboring elements. PNEUMATIC SINUSES The sinus system of Poebrotkerium is less extensive than that of Merycoidodon, as no sphenoidal sinus is present. The frontal sinus is much smaller than that of Merycoidodon: instead of occupying the entire su- praorbital process of the frontal bone, it is found only in the anteriormost part of this process. Its antero— posterior length is only about 4 mm, and it opens into the nasal cavity dorsal to the lacrimal fossa. The maxillary sinus (fig. 28, MS) is considerably longer, but narrower, than that of Merycoidodon. Its greater extent as a cavity independent of the nasal cav- ity is due to the greater thickness in Poebrothem‘um of the palatine plate of the maxilla. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA In Uamelus (Aubert, 1929), in contrast to Poe- brothem'um, the maxillary sinus is absent and the sphenoidal sinus is well developed. This discrepancy in a supposed descendant of Poebrotherium (Scott, 1891) is easily explained: The development of larger cheek teeth would occupy the space in the maxilla formerly filled by the sinus, and the almost threefold increase in skull size would allow room for a sinus ventral to the olfactory lobes (compare Merycoz’dodon). CIRCULATORY SYSTEM OF THE SKULL ARTERIES The internal carotid artery did not, as in Mery‘ooi- dodon, traverse the tympanic cavity; instead it lay in a bony canal formed by the tympanic bulla and the basioccipital and basisphenoid (fig. 27 , I 00 ). As Scott (1891) first pointed out, the internal carotid entered this canal through a foramen anterior to the foramen lacerum posterius. The farthest posterior ap- pearance of the carotid canal is, therefore, just anterior to this foramen and at the level of the vagina processus hyoidei. From this point the canal extends forward 4 mm. to an opening medial to the ostium tympanicum tubae. After leaving the canal, the artery entered the cranium through the foramen lacerum medius, which lies dorsal to the anterior and of the bulla (fig. 26, FLM). The carotid canal in Poebrothem’um differs from that of Camelus only in its less superficial position (because of the more swollen bulla of the former) and in the separation of its posterior foramen from the foramen lacerum posterius. In Poebrothem’um, the size of the carotid canal indicates that the carotid artery was already, as it is in Camelus, relatively unimportant in supplying cranial blood, although still functional. VEINS AND VENOUS SINUSES DORSAL SINUS SYSTEM Poebrotherz‘wm, like Mary/coidodon, differed from living Artiodactyla in the possession of a venous tribu- tary that passed from the orbital plexus through the sinus canal (fig. 15, SC) to the vena collateralis cerebri. The superior cerebral vein in this genus ran ventro- laterally in a space between the ascending plate of the subarcuate fossa (near the anterior end of the pars petrosa) and the descending plate of the squamosal (fig. 27). At the base of the latter plate it entered a small (10 mm. in diameter), subspherical sinus venosus temporalis (fig. 27 , S’VT), whose medial and ventral walls were formed by the tegmen tympani of the pars petrosa and the dorsal side of the tympanic bulla. The size of this sinus is in distinct contrast to that of the homologous sinus in Mary/coidodon. 147 The temporal venous sinus opens into the temporal canal, which, after coursing ventro—laterally, opens upon the surface of the skull in a‘foramen between the auditory bulla and the squamosal bone. This foramen is difficult to find because it is overhung by the root of the zygoma. ‘ The anterior branch of the temporal canal was men- tioned in the discussion of the squamosal bone. BASILAR SINUS SYSTEM The depth of the grooves that extend antero-pos- teriorly alongside the pituitary fossa indicates that the cavernous sinus was a relatively small vessel. So, too, was the inferior petrosal sinus, if it was present at all. The carotid canal (fig. 27, I 0 0) is so small that it could not have contained two functional blood vessels. The inferior petrosal sinus must, then, have been extra- cranial in its course, or absent. No detailed account of the venous system of C’wmelus is known to the author, and it was impossible to determine whether this sinus is present in living Tylopoda. SINUS VENOSUS OSSIS SPHENOIDALIS This venous sinus in Poebrothem’um, with its tribu- tary subsphenoid canals, differed from that of Mery— ~ coidodon only in that. it extended laterally into the root of the alisphenoid bone (fig. 28, SVOS, AS). In figure 28 the anterior subsphenoid canals (830) are seen, extending transversely in the plane of the section from their openings at the sides of the basisphenoid bone. The antero-posterior length of the sphenoidal venous sinus is about 5 mm. Lesbre’s illustration of a sagitally sectioned skull of Camelus (1903, p. 19) shows that the basisphenoid con- tains no cavities of any sort. The above observations suggest that in Poebrothe- m’um the dorsal sinus system was the main path of , drainage of blood from the cranial cavity, and the venous blood from the facial region ran posteriorly through the sphenoidal venous sinus and extracranial paths, rather than through the cranium. NERVES OF THE SKULL REGION The arrangement of the cranial nerves of Poebrothe— Mum, differs from that of Uamelus (Lesbre, 1903) only in the position of the optic nerves. These nerves lie very close together throughout their length, and the optic foramina (fig. 28, 0F) are separated only by the thin medial bony plate formed by the two orbito- sphenoids. The great size of the orbits causes these bones to be closely pressed together in the midline of the skull—a condition common in small mammals, such 148 as the Lagomorpha, Tragulidae and Hypertragulidae. Because of the larger size of the skull, the optic for- amina of the living Tylopoda are separated by the sphenoidal pneumatic sinus, which lies between the orbitosphenoid plates. - CRANIAL MORPHOLOGY OE LEPTOMERYX Leptomerym is a member of the family Hypertragu- lidae, which is well represented in the fauna from the White River group. The members of this family bear a very close resemblance to the living Tragulidae and their relationships have long been a subject of controversy. ' Serial sections of the skulls of the Hypertragulidae do not yield as much information as those of larger mammals, because their delicate bones retain fewer impressions of the endocranial soft parts. Because well-preserved Leptomeryw skulls are rare, one skull was divided sagittally, the left half serially sectioned at 0.5 mm intervals, and the right half kept intact for reference. The skull on which this study is chiefly based is one of Leptomeryw evami Leidy, M. C. Z. 6566 (figs. 29, 30). It was collected by S. W. Garman in 1880, in the Bad Lands of northeastern Wyoming, and was given to the Museum of Comparative Zoology by Alexander Agassiz. BONES OF THE SKULL The supraoccipital portion of the cotissified occipital bone is, unlike that of the Tragulidae, extended pos— teriorly into a nuchal crest, which is filled with diploe' the size of whose cells resembles those of the Camelidae more than those of Merycoidodon. FIGURE 29.—Leptomérym waned, lateral view of skull. FPP, post-parietal Ion-amen. FSA, anterior subsphenoid foramen. M, pars mastoidea of perlotic bone. )0,'occipital bone. PPO, paroccipltal process of exoccipltal bone. SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 The proportion of the occipital surface of the skull formed by the supraoccipital is less than in any other artiodactyl familyfbecause the pars mastoidea is ex- posed on the occipital rather than the lateral surface of the skull (fig. 30, M). The basisphenoid bone, like those of Merycoz'dodon and Poebrothem'um, contains a cavity for the sinus venosus ossis sphenoidalis. The sagittally sectioned skull reveals that the post- clinoid processes are very high (3.5 mm) in proportion to the size of the skull, and that the pituitary fossa, as in the Camelidae and Merycoz'dodon, is shallow. The alisphenoid bone has a posterior process that lies dorsal, not only to the Eustachian tube but also, behind this, dorsal to the tympanic cavity itself. This process thus reaches farther back than in Memoidodon, where it lies dorsal only to the ostium tympanicum tubae. In Traguhzs the alisphenoid seems, insofar as could be determined from external examination of skulls in toto, to have the same relationships as in Leptomerym. The subsphenoid canals, leading to the sinus venosus ossis sphenoidalis, lie for the most part in the alisphe- noid, and their foramina open on its surface (fig. 30, FSA). Considerable portions of the turbinal ossifications of the ethmoid bone were preserved in this specimen. In the back part of the nasal cavity are the roots of three turbinals thick enough to be tentatively termed endo- turbinals. There may well have been more than three of these scrolls in life, but the three preserved ap- parently occupied more than two-thirds of the posterior part of the nasal cavity; it is therefore improbable that I INCH l___.__| Modified after W. B. Scott. Natural size. 80, squamosal bone. To, fotamen jugulare spurlum. TY, tympanlc bone. VPH, vagina processus hyoldei. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA FLA FSA FO TC 80 PEG FSM FLP CF CG M l INCH l I FIGURE 30.——Leptomerya: evansi, ventral view of basis cranii. M. C. Z. 6566. X 2. B, auditory bulla. 0F, condylar foramina. , FLA, foramen lacerum anterlus. FLP, foramen lacerum posterius. F0, foramen ovale, FSA, anterior subsphenold foramen. FSM, stylomastold foramen. M , pars mastoldea of periotic bone. 00, occiptal bone. PBO, petrobasilar canal. SQ, squamosal bone. TO, foramen jugulare spurlum. Leptomeryw had the six endoturbinal scrolls of the modern Artiodactyla (including the Tragulidae) . Many delicate fragments of ectoturbinals can also be seen, but the number of these cannot be estimated. The nasoturbinals (a single scroll) and the maxillo- turbinals (a bifurcated scroll) are identical with those of the Tragulidae, being more heavily ossified than the ethmoturbinals. The external surface of the parietal bone closely re- flects the shape of the brain. It is cancellous only where it fills the gap between cerebrum and cerebellum; elsewhere it is little more than 1 mm thick. Like the parietal, the part of the squamosal partici- pating in the braincase wall is very thin and non- diploic. The horizontal plate of the squamosal is, relative to the size of the vertical plate, much less well developed in Leptomeryw than in most other Artiodactyla. The facies epitympanica (fig. 31, FE) is a plate only 2 mm. 149 wide, roofing the lateral portion of the tympanic cavity. There is no superficies meatus. The posterior hori- zontal process of the alisphenoid forms a larger area of the roof of the auditory bulla than in Merycoz'dodon. TYMPANIC REGION PARS PETROSA OF THE PERIOTIC BONE This bone possesses several peculiarities which are not shared by the pars petrosa of most living Artio- dactyla: unfortunately it was impossible to determine, either from the literature or from dried skulls, whether these are shared by the Tragulidae. The ascending plate forming the lateral border of the subarcuate fossa is, in Leptomerg/w, extraordinarily high. It reaches dorsally a distance of 7 mm. from the plane of the temporal ridge (almost one-half the height of the braincase), and serves as the medial wall of the proximal part of the temporal canal (fig. 31‘, APP). Ventromedially, another process of the pars petrosa projects between the basisphenoid bone and the audi- tory bulla (fig. 31, VPP). Lull reports this feature in Allomeryw planiceps (1922). In most mammals the pars cochlearis lies in or near this postion; in Lepto- meryw it lies dorsal to it, well within the braincase. PAR APP_ ,, g TC_. 80 L 1 FIGURE 31,—Lept0merym evanst Leidy. X 2. Thick section from sec- tions L 14—36, viewed anteriorly from region of bulla. APP, ascending rocess of ars etr s . AS, alisphenoid. p p p o a B, bulla. BS. basisphenoid. FE, facies epitympanica of squamosal. FS, fac1al sulcus. 100, internal carotid canal. PAR, parietal. PET, pars petrosa. PM, pars mastoidea. SF, subarcuate fossa. SQ, squamosal. TC, temporal canal. TT, tegmen tympani. VPP, ventral process of pars petrosa. 150 The subarcuate fossa of Leptomeryw (fig. 31, SF) resembles that of Merycoz'dodon and the carnivores in being a definite but shallow depression in the dorsal wall of the pars petrosa. It is divided into two sub- equal portions by a low antero-posterior ridge, which may indicate that the fossa contained two cerebellar gyri. The subarcuate fossa bears no resemblance to that of the Camelidae. The sulcus facialis of Leptomerya: lies in the extreme lateral side of the roof of the tympanic cavity (fig. 31, F8) . It is separated from the squamosal by a ventrally projecting plate of the pars petrosa, the lower end of which is inserted in the stylomastoid foramen and ex- tends to within a few millimeters of the ventral surface of the skull. MIDDLE EAR AND SURROUNDING STRUCTURES The epitympanic recess in Leptomryw is, consider- ing the size of the middle ear, a fairly long cavity (fig. 31). Its anterior part is covered chiefly by the tegmen tympani of the pars petrosa; laterally it is bounded by the squamosal and the tympanic. Farther anteriorly it is roofed entirely by the tympanic. The epitympanic recess of Tragulus (van der Klaauw, 1931) is like that of Leptomeryw. As in all Artiodactyla, no tympanio sinus is present. The auditory bulla of Leptomerym (fig. 17, B) is hollow, unlike that of most tragulid species. It is only moderately inflated, extending ventrally to the level of the basioccipital. It is in contact medially with the petrosal, a ventral process of which separates it from the basioccipital; dorsally with the posterior process of the alisphenoid (fig. 31) and laterally with the squamosal. It is fused to none of these elements. The tympanio gap (“tympanicumdefekt” of Bondy, 1907), or dorsal opening in the inflated auditory bulla, is small in Leptomeryw. The tympanio bone arches dorsal to the lateral part of the epitympanic recess, so that the tympanic gap is only half as wide as in Merg- coz‘dodon and Poebmthem’um. In Leptomeryw, the gap is closed partly by the pars petrosa, as is usual, and partly by the posterior process of the alisphenoid. The tympanio gap does not extend to the anterior part of the bulla (fig. 31). The incisura tympanica is absent in Leptomerg/w as in the Tragulidae. In the former, the position usually occupied by the incisura, dorsal to the medial end of the external auditory meatus, is covered Within the tympanic cavity by the ventro-lateral plate of the pars petrosa which serves as the lateral wall of the facial sulcus. Leptomerya: thus could not have possessed a pars flaccida of the tympanic membrane. The stylomastoid foramen of Leptomeryw is, like SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 that of the Tragulidae, situated between the paroc- cipital process, the pars mastoidea, the posttympanic process, and the tympanohyal bone (fig. 30, FSM). The tympanohyal separates the foramen from the bulla. EXTERNAL AUDITORY MEATUS The meatus is short, with a diameter almost as great as that of the bulla and twice as large as that of the Tragulidae. It slants posterodorsally. Its posterior * wall is formed by the posttympanic process of the squa- mosal; the tympanic occupies the other three walls of the tube. In the Tragulidae, however, the tympanic forms the entire meatus. PAR! MASTOIDEA OF THE P23103310 BONE As figures 29 and 30 (M) show, the pars mastoidea. is extensively exposed upon the occipital surface of the skull as in the Carnivora, rather than on its lateral surface as in all other mastoid Artiodactyla, includ- ing the Tragulidae, and Hypertmgulus. This char- acteristic of Leptomeryw is probably a primitive one; in this respect Leptomer’yw resembles the hypothetical ancestor of the amastoid Artiodactyla postulated by Helga Pearson (1927, p. 456, 457). The pars mastoidea is large, relative to that of Mery- coidodon and Poebrothem'um (fig. 31, PM). Here, in the back part of the bone, is a large cavity which, hav- ing no direct outlet, must be diploic in nature. In the front part, the mastoid cells are smaller. As in the Tragulidae (Milne-Edwards, 1864), the mastoid process is separated from the bulla by the posttympanic process of the squamosal (fig. 29). PNEUMATIC SINU SES The maxillary pneumatic sinus is the only one present in Leptomeryw. This is also true of the Tragulidae (Aubert, 1929), and seems to be typical of small mam- mals. In Leptomeryx it lies above the cheek tooth row, and extends antero-posteriorly about 5 mm. CIRCULATORY SYSTEM OF THE SKULL ARTERIES N 0 separate posterior carotid foramen is visible on the basis cranii of Leptomeryw (fig. 30), but the serial sections indicate that here, as in Poebrothem’um, Pro- toreodon and a few groups of living mammals, the internal carotid artery entered the carotid canal through an opening anterior to the foramen lacerum posterius. A cross—section of the posterior portion of the carotid canal in Leptomerg/w is seen in figure 31 (I 00 ), which shows a canal between the dorsomedial tympanio wall of the tympanic cavity and the ventral side of the CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA posterior process of the alisphenoid bone. Appar-z ently the artery lies for a short distance in the pos— terior third of the petrobasilar canal (fig. 30, P30), then enters the carotid canal near the dorsal edge of the medial wall of the bulla. The artery extends dorsal to the bulla for only about 2 mm, leaves the canal through the anterior carotid foramen, enters the cra- nium through the foramen lacerum medius, and extends anteriorly in a groove in the floor of the basis cranii. The internal carotid artery in Leptmneryw was much less superficial in position than that of the Tragulidae, in which as a rule, it lies in a simple groove in the medial wall of the bulla. VEINS DORSAL SINUS I! STEM There is no indication in the Leptomeryw skull of the details of the dorsal cranial vessels anterior to the transverse sinus, but several of the distributaries of the sinus are well marked. There was no temporal venous sinus in Leptomeryw, and the temporal canal, bearing the superior cerebral vein, was similar to that of the living Artiodactyla. The superior cerebral vein left the brain cavity high up on its lateral wall, extended ventrally in the tem- poral canal (fig. 31, T0), between the mastoid and squamosal bones, and left the skull through a foramen just behind the external auditory meatus (fig. 30, TU). As in most Artiodactyla, an anterior branch of the temporal canal passed anteriorly in the temporal crest to a foramen on its dorsal side in the region of the root of the zygoma. The transverse sinus of Leptomerym was also drained by a vein that occupied the post-parietal canal, which extends posteriorly in the parietal bone and opens upon the dorsal surface of the braincase through the post- parietal foramen (fig. 29, FPP). BASILAR SINUS SYSTEM Other than the groove in the cranial floor for the cavernous sinus, and the petrobasilar canal for the inferior petrosal sinus (fig. 30, P30), there is no evi— dence as to the condition of this system in Leptomeryw. SINUS VENOSUS OSSIS SPHENOIDALIS This sinus in Leptomerym was about 3 mm long. It differed from those of Merycoidod‘on and Poebrothe— m'um chiefly in that the associated subsphenoid canals extended laterally into the alisphenoid bone (fig. 30, FSA). MORPHOLOGICAL CONCLUSIONS The studies upon which this paper is based have yielded a number of new facts concerning the endo- cranial anatomy of Oligocene Artiodactyla. Some of 151 these observations add to the existing information con- cerning evolutionary trends in this order; others, be- cause of the lack of sufficient data for comparison, can only be recorded in hopes that further studies, bridging the gap between the Oligocene and Recent epochs, will give them significance. The characteristics observed may be divided into three categories: (a) Primitive characteristics. (b) Characteristics whose significance is doubtful, but which are noted because they have never before been observed. (0) Anatomical peculiarities indicating the habits of the genus involved, evolutionary tendencies within the artiodactyl group to which it belongs, or its relation- ships to other artiodactyl groups. The characteristics to which the first two categories may be applied are listed under the headings used above for subdividing the morphological discussions, then the diagnostic anatomical features are discussed individually. BONES OF THE SKULL PRIM ITIVE CHARACTERISTICS 1. In Merycoidodon, the pituitary body was con- tained between two thin, longitudinally oriented, bony plates. These represent the taenia interclinoidalis, the primitive lateral wall of the braincase. 2. In Merycoidodon and Poebrotherium the super- ficies meatus of the squamosal is wide and heavily ossi- fied as compared to that of Leptomerym and the living Artiodactyla. The reduction of the superficies in living genera is concomitant with the shortening and lighten- ing of the bony meatus. 3. Merycoidodon is unique among the Artiodactyla in that the posttympanic process of the squamosal parti- cipates in forming the ventral wall of the external auditory meatus. CHARACTERISTICS OF DOUBTFUL SIGNIFICANCE 1. The mesethmoid bone of Merycoédodon is very heavily ossified midway between the cribriform plate and the anterior nares. This suggests that the meseth- moid and presphenoid bones in this genus ossified sep- arately. If this were the case, this genus would be sharply differentiated from the other Artiodactyla. It is probable, however, that the thickness of the meseth- moid, is simply a part of the heavy ossification of the entire nasal region in Merycoidodon. ‘ 2. The posterior horizontal process of the alisphenoid of Leptomerym extends far enough posteriorly to close the anterior part of the tympanic gap. This is appar- ently most unusual among Artiodactyla, but compara- tive data are incomplete. 152 TYMPANIC REGION PRIMITIVE CHARACTERISTICS 1. The tympanohyal bone of Merycoidodon, Poe- brothem’um, and Leptomerg/a: was inserted loosely into the vagina processus hyoidei. This is in contrast to the living Artiodactyla, in which the tympanohyal is fused to the tympanic in the fundus of the vagina. 2. The tympanic gap of Merycoidodon is larger than that of living Artiodactyla or of Leptomeryw. This is regarded as primitive because it more closely approxi- mates the primitive ring-form of the tympanic (van der Klaauw, 1931) than does the condition in which the bulla is partly closed dorsally. The size of the tympanic gap determines the composi- tion of the roof of the epitympanic recess. If it is small, as in Leptome’rym and most living Artiodactyla, the tympanic itself forms most of the roof. If it is large, as in Merycoidodon and the Tylopoda, the pars petrosa is the important element involved. CHARACTERISTICS OF DOUBTFUL SIGNIFICANCE 1. In Mewcoidodon, the fissura glaseri is almost en- tirely surrounded by the tympanic bone. This is not the case in any living artiodactyl (van Kampen, 1905), or in Poebro‘them'um or Leptomerg/w. It may, at least until further information becomes available, be re- garded as a structure characteristic of M erycoz'dodon. 2. An entotympanic bone is present in Merycoz'dodon. BecauSe of the sparseness of knowledge concerning this bone, even in Recent Artiodactyla, speculation on this fact is useless. 3. The meaning of the presence or absence of the incisura tympanica is often difficult of interpretation. It is missing in Leptomerym and the Tragulidae, prob- ably because the relatively large size of the tympanic annulus, together with the great reduction of the hori- zontal plate of the squamosal, leaves no room for such a structure. The. lack of the incisura in these genera is due to the small size of their skulls. The condition in the Tylopoda is, however, puzzling. The incisura tympanica is missing in the living mem- bers of the suborder (van Kampen, 1905), but well developed in Poebrothem'wm. Only one explanation can at present account for this discrepancy. In the living Tylopoda a portion of the tympanic bone forms the roof of the external auditory meatus, and thus the superficies meatus of the squamosal, which performed this function in Poebrotkem'mn, is excluded from its participation in the attachment of the tympanic mem- brane. This membrane in modern Tylopoda is, there— fore, attached throughout its circumference to a ring of bone; in Poebrothem'um, due to a gap in this ring, it was possible for a dorsal portion (the pars flaccida) of SHORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 the membrane to be attached to a process of the squamo— sal below which lay the incisura tympanica. This evolutionary trend in the Tylopoda conforms with the already mentioned tendency in all mammals toward closure of the tympanic gap. 4. Leptomeryw differs from all other mammals ob- served by the writer or mentioned in the literature in the extreme height of the ascending plate of the pars petrosa, which serves as the lateral border of the sub- arcuate fossa. In this genus, this plate composes almost the entire medial wall of the temporal canal. It probably appears unusually high simply because of the small size of the skull. This supposition is borne out by the large size of the pars petrosa as a whole in proportion to the size of the Leptomeryw skull. It is a recognized fact that, in small mammals, the organs of sense occupy, comparatively, a greater space than in larger ones. 5. A characteristic which, in the present state of knowledge, distinguishes Leptomeryw from all other Artiodactyla is the great ventral extent of that plate of the pars petrosa which forms the lateral wall of the facial sulcus. No functional reason for this condition is evident, nor is it a stage in any known evolutionary trend in skull development. It is not present in the Tragulidae, so that it would not seem necessarily asso- ciated with small skull size. Itis therefore here tenta- tively suggested that this peculiarity may be a hypertragulid (or perhaps only a leptomerycid) characteristic. PNEUMATIC SINUSES PRIMITIVE CHARACTERISTICS In their small extent and number, and in the lack of any interconnections between them, the pneumatic sinuses of the three Oligocene genera here discussed are primitive. This is most strikingly apparent in Mery- ooz'doa’on, whose thick cranial bones were capable of housing a much more complicated sinus system than the animal possessed. This bears out Paulli’s state- ment (1900) that the complicated sinus system of modern type did not appear until late in the Miocene epoch. ARTERIES PRIMITIVE CHARACTERISTICS 1. In the three Oligocene genera studied, evidence was found that the internal carotid artery was func- tional, a primitive condition in the Artiodactyla. The artery was relatively much smaller in Poebrothem'um than in Merycoz’dodon or Leptomerym. 2. The absence in M erycoidodon of a rete mirabile of the intracranial part of the internal carotid artery is, in all probability, also primitive. CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODACTYLA VEINS AND VENOUS SINUSES PRIMITIVE CHARACTERISTICS 1. The sinus venosus ossis sphenoidalis and the sub- sphenoid canals, possessed by all three of the Oligocene genera studied here, were part of an archaic type of venous cranial circulation. This conclusion is based upon their absence in living Artiodactyla as opposed to their apparently widespread occurrence in Oligocene time, and also upon their presence in primitive living mammals: the Insectivora and Marsupialia, as well as the Lagomorpha and some Rodentia. The conclusion that these blood vessels are primitive in character is further borne out by their absence in the Merycoidodon- tidae after the late Oligocene. 2. The vein of the sinus canal, which was possessed by Merycoidodon and Poebrotherium, was another primitive artiodactyl characteristic. The same evi- dence contributes to this conclusion as was cited in the case of the sinus venosus ossis sphenoidalis. 3. The presence of a temporal venous sinus in Mery- coidodon, and to a far lesser extent in Poebrotherium, is due to the fact that the small size of the brain relative to skull size leaves space available for the sinus. 4. The vestigial vena capitis lateralis, observed in Merycoidodon, was probably merely a relic from the embryonic stage, various manifestations of which are often encountered in adult modern Mammalia. ANATOMICAL PECULIARITIES INDICATING HABITS, EVOLUTIONARY TRENDS, OR RELATIONSHIPS Mesethmoid ossification in Merycoidodon—As has been discussed at length above, the extremely strong bony nasal septum of this genus resembles closely that of the peccary, and indicates similar rooting habits. The thickness and extensive development of the turbi- nal bones of this genus were undoubtedly the result of the unusual degree of ossification of the septum. Tendency of Selenodontia to approach the amastoid condition—Comparison of Poebrotherium with the liv- ing Tylopoda, and especially of Merycoidodon with the later Merycoidodontidae, reveals a progressive and dis- tinct reduction in the area of the pars mastoidea exposed upon the surface of the skull. This does not diminish the value of the mastoid-amastoid distinction drawn by Pearson (1927) ; it simply points out that the mas- toid and amastoid Artiodactyla differ in this respect only in the degree of advancement of a trend that is present in both. Absence of the epitympanic sinus.—In this character- istic, the three Oligocene genera examined resemble the living Artiodactyla. In mammals as a whole, the ab- sence 6f the epitympanic sinus is also the rule rather than the exception. 153 Course of the internal carotid artery.—In Merycoid- odon, this artery courses through the auditory bulla as in the Carnivora; in this it differs from all other Artio- dactyla in which the internal carotid is known. Prob-i ably this is true of all the Merycoidodontidae. The other two Oligocene genera studied possessed a. carotid canal medial to the bulla, as in the living Tylo- poda and Tragulidae. In the study of various phylogenetic lines of the Artiodactyla there was observed a tendency to posterior migration of the posterior carotid foramen: in other words, the length of the carotid canal progressively in- creased. This backward migration culminates when the posterior carotid foramen merges with the foramen lacerum posterius. Migration of the posterior carotid foramen was com- pleted early in the evolution of the Merycoidodontidae, much later in the Camelidae. Tendency toward reduction of the internal carotid artery in the Artiodactyla—The internal carotid, ab- sent or non—functional in almost all living Artiodac- tyla, was present and well developed in some Oligocene members of the order, according to the observations recorded here. It was strong in Merycoidodon and Leptomerya; in Poebrotheriuml, oddly enough, it was relatively no larger than in the living Ua/melus. This suggests that, in the Oligocene ancesters of the Tylo- poda, the reduction in size of this artery may have progressed further than in Merycoidodon and Lep- tomeryw, which apparently represented more archaic sidelines of artiodactyl phylogeny. Internal jugular vein replaced by external jugular as dominant efl’erent cranial vessel—In Merycoidodon es- pecially, and to a less degree in Poebrotherium, most of the blood from the facial region and the braincase found its exit from the skull by way of the basilar sinus system and the sphenoidal venous sinus, and thence to the internal jugular vein. In the course of evolution to the modern artiodactyl condition, the sphe- noidal venous sinus disappeared and the ventral petro- sal sinus lost some of its tributaries. The result was that blood from the face adopted a course outside the cranium, While most of the endocranial blood was drained off through the superior Cerebral vein. Both these vessels are tributary to the external jugular vein. The lobulus petrosus of the cerebellum.—This lobule of the brain is absent in all but a few living Artiodac- tyla. In two of these, Orewmnos and Sue, it is very small. In the modern Tylopoda, on the other hand, it is well developed, and is enclosed dorsally by the arch of the posterior semicircular canal. This is also the casein the Oligocene Poebrotherium. In Leptomeryw and Merycoidodon of the Oligocene the lobulus was 154 present and very large; it resembled that of the living ‘ Carnivora in being housed in a deep fossa in the dorsal side of the pars petrosa. It was not arched over by the semicircular canal as in the Tylopoda. The strong similarity, amounting almost to identity, between the lobulus petrosus of the Tylopoda and those of the Lagomorpha and some Rodentia is difficult to explain, especially as the function of this lobule is not definitely known. The consensus of opinion seems to be that it functions in maintaining proper static and kinetic conditions in a fluid medium, since it is highly developed in the Pinnipedia. It may be that this type of lobule in the Lagomorpha serves in maintaining equilibrium in jumping, and that in the Tylopoda it is a relic of ancestral leaping habits in the Artiodactyla, such as are suggested by the double rollers possessed by the artiodactyl astragalus. PHYLOGENETIC CONCLUSIONS Study of the cranial anatomy of M erycm’dodon, Leptomeryw and Poebrothem’wm reveals that these three genera (and, presumably, most other early Oligocene Artiodactyla) possessed structures which are found today only in the Marsupialia, Insectivora, Lago- morpha, and some Rodentia. These characteristics are evidence of the fact that Oligocene artiodactyls were nearer in structure to their primitive, insectivorelike ancestors than might be judged from their superficial appearance. Investigation of the cranial anatomy of Artiodactyla from the Wasatch, Bridger, and Uinta formations is likely to give further information con- cerning the steps involved in the gradual loss of primi- tive mammalian cranial characteristics by the artiodac— tyls. It may even yield specific information concerning the stem group from which the Artiodactyla sprang, presumably in the Paleocene. The crania of the Oligocene Artiodactyla also possess some details of structure which add to the body of knowledge from which, in turn, can be derived a partial understanding of the interrelationships of the various artiodactyl families and suborders. The conclusions resulting from this evidence are discussed below. TYLOPODA Poebmflwrium was an advanced artiodactyl by early Oligocene standards, as is shown particularly by the pattern of its cranial circulation. Its relatively ad- vanced state of evolution facilitates comparison with living Tylopoda and the establishment of Poebrother- {um as one of an almost direct line leading to the mod— ern genera. One of the most striking pieces of evidence linking Poebrothem‘um with the living Tylopoda is its pecu— SI—IORTER CONTRIBUTIONS T0 GENERAL GEOLOGY, 1952 liarly constructed subarcuate fossa, which is identical in the genera of Oligocene and modern times and occurs in no other Artiodactyla, living or fossil. The great antiquity and unique character of this structure is strong evidence of the long independent existence of the suborder, which must have separated from the other artiodactyl lines in the middle Eocene at the latest. Most cranial features of PoebrotheMm, such as its inflated, cancellous bullae, carotid canal and the struc- ture of the middle ear region, bear out the opinion of previous authors that this genus was a direct ancestor of modern Tylopoda. The living Tylopoda, as is shown by their many re- semblances to their Oligocene relative, are no longer advanced members of the artiodactyl fauna. This re- flects the fact, evident in postcranial as well as in cranial structures, that tylopod evolution was rapid in the early Tertiary and proceeded at a much more leisurely rate thereafter. MERYCOIDODONTIDAE Merycoidodon has the greatest number of primitive cranial features of the Oligocene genera examined; it may therefore be regarded as an archaic member of the artiodactyl fauna of the White River group. This agrees with the degree of advancement observed in other merycoidodont genera as compared to that of their contemporaries. The structure of the subarcuate fossa in Merycoid- Odom, is also important taxonomically. Although well developed, it is smaller than that of Poebrothem’um, and is formed in an entirely different manner. This fact supports the majority of paleontologists in deny- ing Riitimeyer’s and Scott’s hypothesis that the Mery- coidodontidae are closely related to the Tylopoda. The subarcuate fossa of Merycoidodon differs only in size from that of Oreaxmmos (one of the Capridae) ; in other living Pecora this structure has disappeared. This evidence is not cited to prove Orecmmos a close relative of Merycoidodon; rather, it is cited as proof that the Pecora once possessed a subarcuate fossa of the type found in Merry/00222003071, and that this fossa has been, since the Oligocene, reduced and finally lost. It may therefore be concluded on the basis of evidence now available that the Merycoidodontidae belong near the base of the phylogenetic tree of the suborder Pecora. Before the above conclusion can be regarded as final, much further investigation will be necessary. The problem of the origin and relationships of the Mery- coidodontidae apparently will depend for its solution upon the unearthing of more details concerning the morphology of other primitive selenodonts and buno- selenodonts of the lower Tertiary. Particularly im- CRANIAL MORPHOLOGY OF SOME OLIGOCENE ARTIODAC'I‘YLA portant in this respect are the Anthracotheriidae, Caenotheriidae, Anoplotheriidae, and Homacodon- tidae. It is possible that research into the cranial anatomy of these primitive families will establish their taxonomic positions more definitely. LEPTOMERYCINAE The cranial morphology of Leptomem/w and related genera strongly supports including them in a subfamily of the Hypertragulidae, equal in status to the subfamily Hypertragulinae. The diagnostic cranial features of the Leptomerycinae are the exposure of the pars mas- toidea upon the surface of the occipital plate (a feature otherwise unknown in Selenodontia) and the presence of a ventral process of the pars petrosa separating the basioccipital bone from the auditory bulla. Both these characteristics are found in Allomem/w, of the John Day formation of early Miocene age, a fact that proves that the leptomerycine line survived as long or longer than that of the Hypertragulinae. The simple subarcuate fossa of Leptomeryw rein- ' forces other cranial evidence in suggesting Pecoran affinities. Again the theories of Rfitimeyer and Scott are contradicted, for these authors believed the Hyper- tragulidae, like the Merycoidodontidae, to have been closely related to the Tylopoda. No conclusive evidence has been adduced concerning the relationship between the Hypertragulidae and the Tragulidae. Many similarities exist between the ex- tinct family and the living one, but probably most of these are due to small skull size. SUMMARY OF PHYLOGENETIC CONCLUSIONS I. The early Oligocene Artiodactyla were not far re- moved from an ancestral group resembling the Insectivora. 2. The Tylopoda represent an evolutionary line that has been independent of all other Artiodactyla since the middle Eocene, at least. 3. The Hypertragulidae are members of the suborder Pecora; the Merycoidodontidae belong close to the base of the phylogenetic tree of this suborder. 4. The Hypertragulidae consist of two subfamilies, the Hypertragulinae and Leptomerycinae, both of which survived from early Oligocene into early Miocene time. SELECTED BIBLIOGRAPHY Arai, H., 1907, Der Inhalt des Canalis Cranio-Pharyngeus. Anatomische Hefte. Arbeiten. Band 33, p. 413. Aubert, E., 1929, Recherches anatomiques sur les sinus osseux des ruminants. Archives Anatomic Histologie Embryologie. 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INDEX Page Page Acknowledgments ____________________________________________________________ 117 Merycoides _______________________________________________________ 122 alisphenoid bone ______________________________________________________________ 123 Merycoz'dodon. _________________________________ 118-155 Allmneryz ____________________________________________________________________ 155 culbertsom‘i ____________________________________________ . . 118, 122,125,136 plam‘ceps ___________________________ 149 evolution ______________________________________________ amastoid condition, significance of tendency toward. __________________ 153 gracilis .................. Amphimeryz __________________________________________________________________ 135 Merycoidodontidae. evolution.. _ anatomical peculiarities indicating habits, evolutionary trends, or relation- mesethmoid ossification, significance- ships __________________________________________________________ 153-154 Mesoreadon ______________________________________ 122 Anihropopithecus. , . 145 Microgale ________________________________________ . 138 arm, 092's ............. 136 midd‘e ear and surrounding structures _________ 132—135, 145—146, 150 arteries of the skull _____________________________________________ 137-138, 147, 150—151 Miztotherium _________________________________________________________________ 135 morphological conclusions __________________________________________________ 151—154 basilar sinus system _________________________________________ 139—140, 147, 151 basiphenoid bone-.. ________________ 120—123 nerves of skull region ___________________________________________________ 141, 147—148 Bibliography _________________________________________________________________ 155 bones of the skull _______________________________________ 118—131, 141—144, 148-149, 151 occipital bone _______________________________________________________________ 118—120 Boo ________________________ 141 Oldfieldthomasia _________________________________________________________ 130, 131, 132 Braclwcrus _______________________________________________________________ 135, 136 orbitosphenoid bone.. 124 Oreamnas _____________ 154 Camelua ____________________________________________________ 134,139,143, 144, 146, 147 Ovis ....................................... 132, 136, 141 Cam's _________________________________________________________________________ 122 arias ______________________________________________________________________ 136 carotid artery, significance of course, reduction 153 , Cebochoerus _____________ 135 parietal bone _________________________________________________________________ 126 characteristics of doubtful Significance ______________________________________ 151, 152 pars mastoidea of periotic bone _________________________________________ 135, 146, 150 Chocropotamus ________________________________________________________________ 135 pars petrosa of periotic bone .................................... 131—132, 144, 149—150 circulatory system of skull ______________________________________ 137-141, 147, 150—151 Pearson, quoted _______________ 135 conclusions, phylogenetic- 155 preinterparietal bone .......... 126 culbertsami, Merycoidodon _______________________________________ 113, 122, 125, 126 periotic bone, pars petrosa oi. Cyclopidius ___________________________________________________________________ 122 planiceps, Allomeryz _________________________________________ ' ................. 149 Dacrythcrium __________________________________________________ 135 pneumatic sinuses.__. ...... _,_. 136-137,146—147,150 Dicoteles __________________ 124, 125, 126, 137 Poebrotherium .................. 118,131, 141—148, 150—155 dorsal sinus system _________________________________________________ 133—139, 147,151 evolution. .. ...... 154 eximium ....................................... 141 Entdodo'n _____________________________________________________________________ 135 labiatu'm ....................................... 141 epitympanic sinus, significance of absence. . . 153 wilstml .............. 141 Epareodo'n _________________________________________________ 122, 123 presphenoid bone... . _________________________________________ 123—124 Erinaccus _____________________________________________________________________ 138 primitive characteristics, artery ........................................... 152 ethmoid bone _______________________________________________________________ 124-126 bones of skull ........................ 151 mum, Leptomeryz.... 143 pneumatic sinuses ___________________ 152 azimium, Paebrotherium.. 141 tympanic region ...... 152 external auditory meatus _______________________________________________ 135,146, 150 veins and venous sinuses ........................................... 153 Promerycochoerus _____________________________________________________________ 122 frontal bone ________________________________________________________________ 126—127 Protorcodon ......................................................... 122, 137, 138, 150 aracilis, Merycoidodim _________________________________________________________ 122 male, Sue ____________________________________________________________________ 122 Hippopotamus“ 135 23:3“ bibliography...—-.-.-.--—.-...-.——-. ..................... Home """""" 145 sinus venosus ossis sphencidalis ________ hmmachua, Lama ..................................................... 145 Hypertraaulus 15o Solenodon """""""" """"""""""""""""""""""""""""""""""" squamosal bone... _._._-.. interpmem bone _____________________________________________________________ 126 subsphenoid veins ................................. Introduction... 117 SW ---------------------------------------------- scrofa ..................................................................... jugular vein, significance of changes in ........................................ 153 71111111 europaea ..................................................... 138 labiatum, Poebrotherium ....................................................... 141 Tapirulus .............. Lama ........................................................................ 146 Tragulu: ............... huanachus --------- turbinal bones._ .. ________ Mptomerycmae, 91701131011- Tylopoda, evolution _______________________ > ________ ”WWI ------------------ tympauic region ............................................ 131-135, 144—146, 149—150 mm: ....................................... evolution ..................................................... veins and venous sinuses ........................................ l:48—141,l47,151,153 Lem: ———————— 122, 137, 138, 140 vomer ________________________________________________________________________ 123 cuniculus ................................................................. 140 lobulus petrosus, significance of development ................................. 153 wilsom', Pocbrothm'um ........................................................ 141 159 i I Eocene and Oligocene Larger F oraminifera From the Panama Canal Zone and Vicinity GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 GEOLOGEC;5.L ‘3'“??"3 LIBRARY Eocene and Oligocene Larger Foraminifera From the Panama Canal Zone and Vicinity \ By W. STORRS COLE GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 Prepared under t/ze anypicey of t/ze Tec/znied/ Cooperation Administration oftne United Statey Department ofState UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1952 UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington '25, D. C. - Price $1.25 (paper) CONTENTS PM“ Description of species—Continued Abstract ___________________________________________ 1 Family Camerinidae—Continucd Page Introduction ________________________________________ 1 Genus Heterostegina- _ _ _ _ _ _ _ _ _ _ - _ _ _ _'_ ________ 11 Previous records of larger Foraminifera ................ 1 Family Amphisteginidae _________________________ 14 Distribution and correlation of faunas ................. 3 Genus Helicostegina _________________________ 14 Gatuncillo formation (middle (?) and upper Eocene)- 3 Family Cymbaloporidae _________________________ 14 Marine tongue (?) in Bollio ('3) formation, Gatun Genus Fabiania ______________________________ 14. Lake area, Canal Zone (upper Eocene or lower Family Orbitoididae _____________________________ l5 Oligocene) ___________________________________ 5 Genus Lepidocyclina _________________________ 15 Thin lenses of algal limestone in upper part of Bohio Genus Helicolepidina ________________________ 30 formation of Pacific coastal area (upper Oligocene) - 6 Family Discocyclinidae __________________________ 31 Cainiito formation (upper Oligocene part) ........... 6 Genus Asterocyclina _________________________ 31 Description of species _______________________________ 8 Genus Pseudophragmina _____________________ 35 Family Lituolidae _______________________________ 8 Family Miogypsinidae ___________________________ 35 Genus Yaberinella ___________________________ 8 Genus Miogypsina __________________________ 35 Family Camerinidae ............................ 8 References cited ____________________________________ 37 Genus Camerina ____________________________ 8 Index _____________________________________________ 39 Genus Operculinoides ________________________ 9 ILLUSTRATION S [Plates 1-28 follow index] PLATE 1. Eocene species of Operculinoides and Oligocene species of Heterostegina. 2. Eocene and Oligocene species of Operculinoides. 3. Eocene and Oligocene species of Operculinoides and Camerina. 4. Eocene and Oligocene species of Heterostegina. 5. Oligocene species of Heterostegina. 6. Eocene species of Yaberinella, Helicostegina, and Fabiam‘a, and Oligocene species of Heterostegina. 7—14. Eocene species of Lepidocyclina. 15. Eocene and Oligocene species of Lepz’docyclina. 16—19. Oligocene species of Lepidocyclina. 20. Eocene and Oligocene species of Lepidocyclina and Eocene species of IIelz'colepirlz'na. 21, 22. Oligocene species of Lepidocycli'na. 23. Eocene and Oligocene species of Lepidocyclina. 24. Eocene species of Helicolepidina and Oligocene species of Miogypsina. 25. Oligocene species of Miogypsina. 26, 27. Eocene species of Asterocyclina. 28. Eocene species of Asterocyclina and Pseudophragmina. Pag FIGURE 1. Tertiary formations of Panama Canal Zone and adjoining parts of Panama ___________________________________ 5 2. Map of Panama Canal Zone and adjoining parts of Panama showing location of samples studied for present report ___________________________________________________________________________________________ 3 XXX EOCENE AND OLIGOCENE LARGER FORAMINIFERA FROM THE PANAMA CANAL ZONE AND VICINITY By W. STORES COLE ABSTRACT Forty species and two varieties from the Eocene and Oligocene of the Panama Canal Zone and vicinity are discussed and i1- lustrated. Twenty-one species and one variety are reported from the middle (?) and upper Eocene Gatuncillo formation. Eight upper Eocene species, including two species not found in the Gatuncillo formation, occur in a marine tongue (?) in the Bohio (‘3) formation of the Gatun Lake area. Nine species, of which one, Lepidocyclina (Pliolepidina) gubernacula, is new, are recorded for the first time in the Eocene of Panama. Seventeen species and a variety are found in the upper Oligocene part of the Caimito formation and in the fossiliferous upper Oligocene part of the Bohio formation in the Pacific coastal area. Ten species and one variety were not known previously in the Oligocene of Panama. At least most of the Gatuncillo formation, by means of its fauna of larger Foraminifera, is correlated with the upper Eocene San Fernando (or Mount Moriah) formation of Trinidad and the upper Eocene Ocala limestone of Florida. It should be noted, however, that the Gatuncillo contains two species which are reported only from the middle Eocene. The parts of the Caimito formation containing larger Foraminifera and the upper part of the Bohio formation in the Pacific coastal area are cor- related with the Suwannee limestone of Florida, the Antigua formation of Antigua, and the Meson formation of Mexico, all of late Oligocene age. INTRODUCTION During the past year and a half it has been a great pleasure to study the larger Foraminifera in a series of samplesfrom the Eocene and Oligocene strata of the " Panama Canal Zone and vicinity. These samples were collected by W. P. Woodring of the U. S. Geo- logical Survey, in cooperation with T. F. Thompson, former Chief of the Geological Section of the now abol- ished Special Engineering Division of the Panama Canal. Mr. Thompson and the geologists of his staff, particularly S. M. Jones, J. R. Schultz, R. H. Stewart, and J. A. Tavelli, not only provided assistance in making the collections, but also supplied stratigraphic data. Mr. Woodring in turn freely and generously placed all of this information at my command. To all of these geologists, and especially to Mr. Woodring, I am indebted and grateful. The stratigraphic terminology recently proposed by Woodring and Thompson (1949, pp. 992—996), shown with slight modification in figure 1, is used in the present report. Jones (1950, pp. 893—922) in an article entitled “Geology of Gatun Lake and vicinity, Panama” does not entirely agree with the terminology proposed by Woodring and Thompson. It is beyond the scope of the present work, however, to attempt to reconcile these differences. Twenty-nine samples, of which 16 are referred to the Eocene and 13 to the Oligocene, were studied. The samples were selected from a group of 45 to represent different geographic areas, the greatest possible strati- graphic range, and various lithologic facies. The index map (fig. 2) shows the localities where the specimens were collected. The description. of the localities is given in the discussion under the heading “Distribution and correlation of faunas.” Although larger Forami- nifera could be collected at an almost indefinite number of localities in the Gatuncillo and Caimito formations, particularly in the limestones of the Gatuncillo and in limestones of the middle member of the Caimito in the Gatun Lake area (Woodring, oral communication), it is believed that the representative samples which were selected give an accurate reflection of the Panamanian faunas. ' Forty distinct species and two varieties are discussed and illustrated. Of these, 23 species and 1 variety are from the Eocene, and 17 species and 1 variety are from \ the Oligocene. Nine species, of which 1 is new, are recorded for the first time in the Eocene of Panama and 10 species and 1 variety not previously known in the Oligocene of Panama are placed on record. All of the Panamanian specimens are deposited in the collec- lcction of the U. S. National Museum. PREVIOUS RECORDS. OF LARGER FORAMINIFERA Lemoine and R. Douvillé (1904, pp. 14, 20, 21) described the first larger Foraminifera from Panama when they named specimens from their Haut-Chagres locality (San Juan de Pequeni, a locality in the upper Chagres Valley submerged by Madden Lake) Lepz'do- cyclina. chapert', and others from Pena Blanca (sub- merged by Gatun Lake) Lepidocyclina canellei. These species were assigned to the Aquitanian (upper Oligocene or lower Miocene). Cushman (1919a, pp. 89—102) reported on collections made by T. Wayland Vaughan and D. F. MacDonald in the Canal Zone and by MacDonald in western Panama. He recorded 10 species, all of which he placed in the Oligocene, although he questioned this assign- ment in the case of 3 species. The names used by 1 2 , EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE Age Gaillard (ézingiigozaecmc Side' Gatun Eggzta'ce:n:r§°%:ribbean Madden basin, Panama Quebrancha syncline, Panama EARLY PLIOCENE _ _ _ ? _______ ? _. __._. Chagres sandstone LATE ’l;oro limestone membe7r liilliiiiillii? ?i Lu 2 3 MIDDLE Gatun formation 9 2 7 7 _ _ .7 _______ ? _ _ T Alhajuela sandstone member EARLY — Lia—BEch'SrTnEti—mf Pedro—Wgfiel— _ agglomerate, Panama tufi‘ g Calcareous sandstone member Cucaracha formation f"; Emperador limestone member E Chilibrillo limestone member l I h 3 o - 7 7 7 Culebra formation 7 . ~ : 1; Limestone lens _ _ ______________ Upper member .2 E : Calcareous siltstone member 1;; '5 Pyroclastic clay member 8 .g LATE E o "g E Lu 0 . '36 . uzJ Middle member :1 03:12:32: 2:332:16 DE Quebrancha limestone member 0 E ? / 2 8 . _ '& L .3 g 3 Las Cascadas agglomerate $333532? mgriillfgr o g Volcanic member , . E O EARLY Bohio formation 3 . . . . . .._, Bas Obispo formation Bas Obispo Bohio .2 Gritty sandstone member —————————————— formation > formation g m LATE EOCENE Gatuncillo formation Gatuncillo formation Gatuncillo formation CRETACEOUS(?) Basement complex Basement complex Basement complex FIGURE 1.—Tortiary formations of Panama Canal Zone and adjoining parts of Panama. (After Woodring and Thompson (1949, fig. 2) with slight modification.) are assigned these , species at present. Cushman’s species that were recorded only from localities in western Panama are so specified in the table. ' ‘ Cusliman, except Orbitolites americana which does not occur in the collections described in the present report, are given in the following table with the names Which Larger Foraminifera from the Canal Zone and Panama recorded by Cushman (1919a) Name used at present L. (Lepidocyclina) canellei Lemoine and R. Douvillé. Probably L. (Lepidocyclina) waylandvaugham‘ Cole. Name used by Cushman Lepidocyclina canellei Lemoine and R. Douvillé (pl. 34, figs. 1—6) ________ Lepidocyclina chaperi Cushman [not Lemoinc and R. Douvillé] (pl. 35, figs. 1—3; pl. 36). Lepidocyclma vaughani Cushman (part: pl. 37, figs. 4, 5; pl. 38) __________ L. (Nephrolepidina) vaugham’ Cushman. chidocyclina vaugham‘ Cushman (part: pl. 37, figs. 1 ('3), 2, 3) __________ Probably L. (Lepidocyclina) waylandvaughani Cole. chidocyclina panamensis Cushman (pl. 39, figs. 1—6), western Panama.-- L. (Pliolepidina) pustulosa iobleri H. Douvillé. Lepidocyclina macdonaldi Cushman (pl. 40, figs. 1—6), western Panama___ L. (Plialepidina) macdonaldi Cushman. . . Multicyclina duplicate Cushman (pl. 41, figs. 2-4), western Panama ______ L. (Pliolepidina) pustulosa H. Douvillé, microspherie ' generation. 7 7 7 ' Orthophragmina minima Cushman (pl. 41, fig. 1), western Panama ______ Asterocyclina minima, (Cushman). , _ _ Heterosteginoides paname’nsis Cushman (part: pl. 43, figs. 3—8) _______ p--- Miogypsina (Miolepidocyclina) panamcnsis (Cushman). Heterosteginoides panamensis Cushman (part: pl. 43, figs. 1, 2) __________ Miogypsina (Miogypsina) antillea (Cushman). Nummulites panamensis Cushman (pl. 43, figs. 9, 10) ____________________ Operculinoides panamensis (Cushman). , Nummulites davidensis Cushman (pl. 43, fig. 11), western Panama ________ Probably Operculinaides ocalcmus (Cushman). Later, Cushman (192“, p. 39) in a summary entitled Vaughan (1923, p. 257) reclassified specimens in— “The American Species of Orthophragrm'na and Lepido- cyclina” correctly assigned the limestone at David (in ‘Chiriqui Province, western Panama) containing Ortho- phmgmina minima to the Eocene, but he placed L. panamensis and L. duplicate in both the Eocene and Oligocene. eluded by Cushman in Lepidocyclina vaugham' and described another new species which he. named L. miraflorensis. Later, Vaughan (1924) divided Hetero- steginoides panamensis Cushman and named the new species Miogypsina cushmaml. Vaughan (1926) recog— nized as upper Eocene the following species from San DISTRIBUTION AND CORRELATION OF FAUNAS 3 Juan de Pequeni, the type. locality of Lepidocyclina chaper'i in the Chagres Valley, now flooded by Madden Lake: Opercult'na, sp. cf. 0. ocalana. Cushman, Hetero- stegina ocalana glabra. Cushman, Asteriacities georgz'ana (Cushman), Lepidocych'na (Nephrolem’dina) chaperi Lemoine and R. Douvillé, Lepidocyclina sp., and Discocyclina. sp. Coryell and Embich (1937, p. 305) described a new species, Asterocyclinc gamboaensis, from Eocene strata in the upper Chagres Valley near the Village of Tran- quilla, also now flooded by Madden Lake. This species is illustrated by a drawing of only the exterior and, therefore, cannot be recognized definitely. It is probably a specimen of A. georgiana. (Cushman). Cole (1949, pp. 267—275) described an Eocene fauna from core hole SL—84 in the Rio Agua Salud area (Canal Zone), 3.6 miles northwest of Frijoles, and from outcrop float from the same locality. A list of the species recorded from these samples is included in the list of species recovered from the Gatuncillo formation in the samples discussed in the present paper. The only species described from Panama concerning which uncertainty must exist is Lepidoc clina (Nephro- lepidina) decorate H. Douvillé (1924), from the type 10- cality of L. chaperi. At the present time it is impossible to identify this species with any of the known Panama- nian species. There is the possibility that it was based on a form of L. chaperi with unusually large pillars. DISTRIBUTION AND CORRELATION OF FAUNAS GATFUNCILLO FORMATION (MIDDLE(P) AND UPPER EOCENE) The Gatuncillo formation is the oldest fossiliferous for- mation in the Canal Zone and nearby. The distribution of the species in the Gatuncillo is shown in the chart on page 4, which includes the species previously reported from the Rio Agua Salud area (Cole, 1949, pp. 267—275). The description of the localities follows the chart. 79°30’ 9AM M 90 // Ev“- 0‘ 180d38 \‘ _ / nvo arm Colorado 3 Island 15' away 38 iraflores 37 FM Miraflores Lake droza l l Cocoli HIGHW‘V HIGHWAy 79°30 FIGURE 2.—Map of Panama Canal Zone and adjoining parts of Panama showing location‘of samples studied for present report.- (After Woodring'and Thompson (1949, fig. 1) ’ i with slight modification.) 4: EOCENE AND OLIGOCENE LARGER FORAMINI’FERA IN THE CANAL ZONE Distribution of species from the Gatuncillo formation 10 Madden basin Quebrancha syncline £133.21 FnRjiiies (1%: 1 Fossil collecting localities 15 108 131 1312. 132 150 22a 23 124 125 140 1'45 SL—84 137 1383 YaberinellajamaicensisVaughan ______________ ”an” X X __-, -,1_____-__--_-___-____-_--- __________________ Operculinoidesfloridensis (Heilprin) ___________ __o_ X ----____-___ _----_-_ ____ ____________.____ X ____________ jacksonensis (GravellandHanna) _________ _,__ X ____-,_,- ”as---_-_____1_-_____-__----__ __________________ moodybranchensis (GravellandHanna)_-_--____ X ___-.._---_------____,_---__--___-______-_ __________________ ocalanus(Cushman) _____________________ ______- “n X X ___-_-________-_ X X ____ X ______ X vaughani(Cushman) _____________________ _________--- X ,__________--___ ____ _--_ X -___ ___________________ Camerinostriatoreticulata(L.Rutten) .......... -_-_-_1-___________,V1_____ X -_-_ X X X X X ______ HeterosteginaocalanaCushman _______________ _-____-_,-____________-- X _-______ X X ____ __________________ Fabianiacubensis (CushmanandBermfidez)---- X _-__ X X --______ X --___-______ X __-_ ____________ X HelicosteginasoldodensisGrimsdale ____________ .____-_-_____ ________ ____ X ________ -_-_________ __________________ Lepidocyclina (Lepidocyclina) montgomeriensis Cole _____________________________________ ____ X -_____--,o_-_-_______--_,--, X ______,- X , ____________ (Pliolepidina) gubernaculaCole, n. Sp ______ __-_ __-- ____ __ ____---_ X X _-----_--_____-_ ...... , ____________ macdonaldiCushman ________________ X____ X X X X___--___ X X X X X‘ ...... X pustulosaH.Douvillé ________________ X ---_ X X X X X _--_ X ____ X X X X X pustulosatobleriH.Douvillé __________ ____ X ____ X X --_-_______- X -o- ____ X X ______ X (Nephrolepidina) chaperi Lemoine and R. Douvillé _____________________________ X _-____-____-__-- X X X -___ X X --__ ______ X X HelicolepidinaspiralisTobler _________________ ____ -_---_______ X X X _____--- X ____ ____ X X ______ Asterocyclinageorgiana(Cushman) ............ ____ ____ _____-__ X ____ X ____ X X --_. X X _____________ mariannensis (Cushman) _________________ ____----____ __-- -_--________ _---____-___ X __-- __________________ minima(Cushman) ______________________ _.___ ___- _-__ _____-----__ X -_____-_-___ X 0-, X ____________ Pseudophragmina (Proporocyclina) flintensis ‘(Cushman) _______________________________ __-- _______-----________ --__-___ ____ X X ____ X ____________ Madden Basin, Panama 15. Madden Airfield, about 1,000 feet north of north end of paved runway. Algal limestone. J. R. Schultz, T. F. Thompson, and W. P. Woodring, 1947. 108. Road to Madden Airfield, 0.5 mile northeast of Calzada Larga. Marly limestone. T. F. Thompson, 1948. Also a collection made by T. F. Thompson and W. P. Woodring, 1949. 131. South side of Rio Pequeni near head of Madden Lake, 400 feet west of former Canal Zone Pequeni Police Substation. Thin-bedded limestone, 8 feet above base of Gatuncillo formation. T. F. Thompson and W. P. Woodring, 1949. 131a. Same locality. Thin-bedded nodular-weathering lime- stone, 25 feet higher stratigraphically. T. F. Thomp- son and W. P. Woodring, 1949. 132. West shore of Madden Lake at abandoned Salamanca Gaging Station. Fairly soft limestone. T. F. Thomp- son and W. P. Woodring, 1949. 150. Trail west of Madden Lake, 3 miles north of Madden Dam. Limestone. T. F. Thompson and W. P. Woodring, 1949. ' Quebrancha syncline. Panama 22a. Transisthmian Highway, 4.1 miles in direct line north- west of Rio Gatuncillo bridge. Calcareous sandstone, 0.25 to 0.5—inch thick, in silty mudstone. J. R. Schultz and W. P. Woodring, 1947. 23. Transisthmian Highway, 3.6 miles in direct line north- west of Rio Gatuncillo bridge. Calcareous mudstone. J. R. Schultz and W. P. Woodring, 1949. 124. Road to Nuevo San Juan, 0.4 mile southwest of junction with Transisthmian Highway. Fairly soft limestone. T. F. Thompson and W. P. Woodring, 1949. 125. Road to Nuevo San Juan, 1.3 miles southwest of junction with Transisthmian Highway. Fairly soft limestone. T. F. Thompson and W. P. Woodring, 1949. 140. Transisthmian Highway, 4.6 miles in direct line north- west of Rio Gatuncillo bridge. Poorly sorted, gritty sandstone. T. F. Thompson and W. P. Woodring, 1949. 145. Trail on east side of Rio Gatuncillo, 1.3 miles northeast of Transisthmian Highway bridge across Rio Gatun- cillo. Soft limestone. W. P. Woodring, 1949. Rio Agna Salud area, Canal Zone SL—84. Core hole SL—84; 1,000 feet southeast of head of Que- brada La Chinilla arm of Gatun Lake and 200 feet northeast of pipeline road. Moderately soft limestone. Drilled in 1947. Rio Frijoles Area, Canal Zone 137. Pipeline road, 4 miles northwest of west end of Gamboa bridge. Fairly soft limestone. W. P. Woodring, 1949. Gamboa Area, Canal Zone 138a. 1.2 miles north—northwest of west end of Gamboa bridge, on road to core holes SL—94 and SL-96, 50 feet south of bridge across drainage ditch. Fairly soft limestone. T. F. Thompson and W. P. Woodring, 1949. The larger Foramim'fera of the Gatuncillo formation consist overwhelmingly of species recorded elsewhere in formations of late Eocene age. Three of the species, however, evidently are found also in the middle Eocene; in fact, two (Yoberinella jamaicensis and Fabiania cubensis) up to this time have been recorded only from the middle Eocene. Two samples from the base of the Gatuncillo contain Y aberinella jamaicensis Vaughan, a species recorded only from the Yellow limestone of Jamaica, which is assigned to the middle Eocene. Moreover, several samples from widely different parts of the Gatuncillo DISTRIBUTION AND CORRELATION OF FAUNAS 5 contain Fabiania cubensis (Cushman and Bermudez). This species is reported, to date, only from the middle Eocene of Cuba and Florida. Yet in Panama these two species occur with many others which elsewhere mark the upper Eocene. The genus Yaberinella has been reported from a known upper Eocene unit in Jamaica (Vaughan, 1929, p. 374). These specimens, however, were referred to a distinct species, Y. trelawniensis. In the present study it was found that this species and Y. jamaicensis could not be discriminated. It is assumed that the range of Y. jamaicensis extends from middle to upper Eocene. Fabiania occurs in Cuba not only in deposits which contain middle Eocene species, but also in deposits which the writer and others consider to be late Eocene in age. Thus far, no satisfactory criteria have been devised from distinguishing specimens of this genus found in the middle Eocene from those which occur in the upper Eocene. Therefore, F. cubensis may range from middle to late Eocene, or the understanding of the criteria upon which difl’erentiation could be based is not developed sufliciently. There are other records which suggest that certain species of larger Foraminifera commonly thought to be restricted to the upper Eocene range from middle to upper Eocene. Vaughan (1928, pp. 281, 290) reported the occurrence of ' Lepidocyclina pustulosa with Dic- tyoconus puilboreauensis (=D. americanas) in Jamaica. Cole (1944, pp. 34, 69) recorded the occurrence of L. pastalosa in a deep well in Florida occurring strati- graphically below the D. americanas zone and in association with other middle Eocene species. It would appear from these scattered records that certain species range from middle into upper Eocene. The writer, however, does not know of any authenti- cated record of upper Eocene larger Foraminifera occurring in the lower Oligocene. Because the Gatun- cillo may include deposits of middle Eocene age, it is referred to the middle ( ?) and late Eocene. The fauna of the Gatuncillo formation is dominated by species which are characteristic of the Ocala lime- stone of Florida and the San Fernando . (or Mount Moriah) formation of Trinidad. There, is an inter- mingling of species from these areas. Certain species of the known fauna of Panama and Trinidad, as Oamerina striatoreticalata, have not been reported to date from Florida; whereas others that occur in Pan- ama and Florida, as Asterocyclina mariannensis, have not been reported from Trinidad. These omissions may be the result of insufficient collecting or of regional faunal differentiation 990815¥52 MARINE TONGUE (P) IN BOHIO (P) FORMATION, GATUN LAKE AREA, CANAL ZONE (UPPER EOCENE OR IfOWEROLIGOCENE) Two samples from Trinidad Island, in the western part of Gatun Lake, contain the species listed in the following chart: Species from Trinidad Island Localities 149 1495 Operculinoides jacksonensis (Gravell and Hanna)- X X kugleri Vaughan and Cole _________________ X X trinitatensis (N uttall) _____________________ X X Camerina striatoreticulata (L. Rutten) _ - _ _ ; _____ X Fabiania ‘cubensis (Cushman and Berml’ldez) _ _ _ _ X Lepidocyclina (Pliolepidina) macdonaldi Cush- ' man ________________________________ ‘ ______ X X pustulosa H. Douvillé ________________ X X pustulosa tobleri H. Douvillé __________ X 149. Northeast coast of Trinidad Island. Dark gray sandy siltstone, basal 10 feet of exposed section. T. F. ‘ Thompson and W. P. Woodring, 1949. ' 14%. Same locality, about 10 feet higher stratigraphically. Three-foot ledge-forming silty medium-grained cal- careous sandstone containing few small pebbles, few worn small heads of calcareous algae, and worn tips of Turritella. T. F. Thompson and W. P. Woodring, 1949. The two samples from Trinidad Island contain eight species of larger Foraminifera, all of which, with the exception of L. (P.) pustulosa and Fabiam'a cubensis, are restricted to the upper Eocene elsewhere. The assignment of these samples to the Eocene on the basis of the larger Foraminifera was made before for- mation assignment of the samples was known to the writer. Woodring (oral communication), however, doubtfully places these samples in a marine tongue in the Bohio formation. According to him, the molluscan fauna from the siltstone exposed on Trinidad Island is the same as the lowervOligocenefauna reported from Vamos Vamos and Palenquilla Point (Woodring and Thompson, 1949, pp. 230—231), and the provisional formation assignment used for those lOcalities is adopted for Trinidad Island. The Bohio formation overlies the Gatuncillo formation in the northeastern part of the Canal Zone and east of the Zone. . It should be noted that the samples from Trinidad / Island are the only ones upon which there 1s not com- plete age agreement on the basis of the larger Forami- nifera and mollusks. Because these samples contain eight species of larger Foraminifera, none of which has been reported from the lower Oligocene, it is not poSsible at the present to reconcile the conflicting evidence For the time being the siltstone at Trinidad Island is con- sidered upper Eocene or lower Oligocene. ., There is always the possibility that the, larger Foraminifera in these samples were reworked, but the 6 “ EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE evidence is against this hypothesis, as the specimens show little or no evidence of erosion. Moreover, there is not an admixture of faunas; the species are all from the Eocene, and all except two occur in the Gatuncillo formation. No discocyclinids were found at Trinidad Island, but none was found in seven samples from the Gatuncillo. If these localities represent the lower Oligocene as it is known in Florida, such species as Lepidocyclfna mantelli and Opercult'noides dias might be expected to occur instead of Eocene species. THIN LENSES 0F ALGAL LIMESTONE IN UPPER PART BOHIO FORMATION OF PACIFIC COASTAL AREA (UPPER OLIGOCENE) At two localities in the Pacific coastal area, thin lenses of algal limestone in typical massive poorly sorted or unsorted basaltic conglomerate of the Bohio forma- tion yielded the following species. Both localities represent horizons near the top of the Bohio of that area. Species from Bohz’o formation of Pacific coastal area Localities “ 88 39 Heterostegma antillea Cushman ________________ X X Lepidocyclina (Lepidocyclina) parvula Cush1nan-- _ - _ _ X waylandvaughani Cole _____________________ yumagunensis Cushman ______________ -_-_ X yumagunensis morganopsis Vaughan_--- X -' (Nephrolepidina) vaugham’ Cushman ________ X _____ (Eulepidina) favosa Cushman ______________ X X gigas Cushman __________________________ - - _ - X 38. Transisthmian Highway. 0.6 mile north-northwest of junc- tion with Panama National Highway. J. A. Tavelli and W. P. Woodring, 1947. 39. Transisthmian Highway, 5.7 miles north-northwest of junc- tion with Panama National Highway, about 200 feet north of last (proceeding northward) crossing of Con- tinental Divide. J. A. Tavelli and W. P. VVoodring, 1947. The only species found in the Bohio formation but not in the overlying Caimito formation are Lepidocyclina. (Eulepidina) facosa Cushman and L. gigas Cushman. In the Gulf Coast of the United States in a zonation proposed by Gravell and Hanna (1938, p. 987) there are four larger foraminiferal zones above the top of the Eocene in ascending order: (1) Lepidocyclt'na mantelli zone, (2) Lepidocycl’ina supera zone, (3) Lepidocycltna (Eulepidina) zone, and (4) Miogypsina-Heterostegina zone. In Panama there is a similarity in that Eulepidina appears in the Bohio formation and in one sample from the lower part of the middle member of the Caimito formation in the Gatun Lake area. Three samples from the Caimito formation, however (including two from the member just mentioned) contain Miogypsina. The two lower zones have not been found as yet in Panama. In the Gulf Coast of the United States Lepidocyclina favosa and L. undosa occur in the Suwannee limestone of Florida and in the Chickasawhay limestone of Alabama (Cole, 1945, p. 22; Gravell and Hanna, 1938, p. 987; Cooke, Gardner, Woodring, 1943, p. 1715). These formations Correlate with the Meson formation of the Tampico Embayment and the Antigua forma— tion of Antigua as well as other beds elsewhere in tropical America. BIacNeil (1944, p. 1314) placed the Chickasawhay limestone and its equivalent, the Suwannee limestone, above the Vicksburg group and below the Tampa lime- stone. This would be the equivalent of the Chattian stage, or upper Oligocene. For many years the Eulepidina zone was considered to be in the Glendon limestone on the mistaken as- sumption that this unit in Florida is the one which contains these forms (Cooke and Mossom, 1929, pp. 67—73). Recently, MacNeil (1944, p. 1351) and Cooke (1945, p. 90) have assigned the limestone containing Eulepidina in Florida to the Suwannee limestone. The Meson formation of the Tampico Embayment and the Antigua formation of Antigua are late Oligocene in age, correlating with the Suwannee limestone of Florida, rather than middle Oligocene, an age which was assigned them because of the erroneous correlation with the Glendon Limestone (Vaughan, 1933, p. 40). CAIMITO FORMATION (UPPER OLIGOCENE PART) The following chart shows the distribution of species from the Caimito formation, which overlies the Bohio formation. No fossils have so far been found in the lower member of the Caimito in the Gatun Lake area. The upper three members in Madden basin contain mollusks of early Miocene age. (See fig. 1.) Undifferentiated Caimflo Formation, Pacific Coastal Area, Panama (Upper Oligccene) 37. Transisthmian Highway, 0.25 mile north—northwest of junction with Panama National Highway. Thin lens of algal limestone in tufl and tuflaceous sandstone. J. A. T avelli and W. P. Woodring, 1947. Middle Member, Gatun Lake Area, Canal Zone (Upper Oligocene) 43. About 150 feet eastward up path from west landing at Darien. Algal limestone. One—quarter mile southwest of U.S.G.S. locality 6021 (a cut, now covered with soil and vegetation, on Panama Railroad), the type locality of chidocyclina (Nephrolepidina) vaugham', but presum- ably a little higher stratigraphically in middle member. S. M. Jones and W. P. Woodring, 1947. 45.'Peninsula north of Barbacoas Island, in field 0.8 mile northeast of Lighthouse 13. Pebbly calcareous tuf- faceons sandstone. S. M. Jones and W. P. Woodring, 1947. 53. Low garden islet 0.25 mile northeast of landing at Barro Colorado Island. Soft sandy calcareous siltstone. S. M. Jones and W. P. Woodring, 1947. 55. Panama Railroad, east side of second cut southeast Of Bohio Peninsula. Soft calcareous tuffaceous sandstone. U.S.G.S. locality 6025, the type locality of Lepidocyclina pancanalis and M iogypsina (Miolepidocyclina) pana- mensis. S. M. Jones and W. P. Woodring, 1947. Northward-flowing stream 0.25 mile east of Rio Caraba, 2.1 miles southwest of west end of (Gamboa bridge. Medium-grained poorly sorted silty tuffaceous sandstone resting on conglomerate. R. H. Stewart, 1948. Also a collection made by W. P. Woodring, 1949. 110. DISTRIBUTION AND CORRELATION OF FAUNAS Distribution of species from upper Oligocene part of Caimito formation Pacific Quebrancha coastal Gatun Lake area Madden basin syncline area area Undifler- Up r Calcarequs sand- Quebrancha entlated Middle member memplier stone-Siltstone limestone member member member Localities 37 43 45 53 55 no 54 30 121 123 112. Operculinoides panamensis (Cushman) _____________________________ ____ _-_- ____ X ____ ________ __-_ ____ ____ ________ Heterostegina antillea Cushman ___________________________ X X X -___ ____ ____ ________ ____ ____ ____ X israelskyi Gravel] and Hanna _________________________________ ___- ____ _-__ X X ________ --__ ____ ____ ________ panamensis Gravell _________________________________________ -___-_______ X ____ ________ -__-___- ____ X Lepidocyclt’na (Lepz‘docyclt’na) asterodisca Nuttall ____________________ w _ _ - _ _ - _ _ _ _ _ _ - _ _ canellei Lemoine and R. Douvillé _________________________ X _ _ _ _ X X _ __ _ paroula Cushman-____--________--______' ________ X ____ X ____ X ___- waylandoaughani Cole ___________________________________ -___ ____________ __-_ yurnagunensis Cushman _________________________________ _ _ _ _ X _ _ _ _ X _ _ _ _ yurnagunensis marganopsis Vaughan ______________ X _ _ _ _ X X _ _ _ _ _ _ _ _ (Nephrolept'dt’na) dartom' Vaughan _____________________________ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ - - tournoueri Lemoine and R. Douvillé _______________________ - _ _ _ X _ _ _ _ _ - _ _ _ _ _ _ vaugham' Cushman ______________________________ X X _ _ _ _ _ _ _ _ _ _ _ _ (Eulepidina) undosa Cushman ________________________________ _ _ _ _ X _ - _ _ _ _ _ _ _ _ _ _ Miogypsina (Miogypsina) antillea (Cushman) _______________ X _ _ _ - _ _ _ _ X - _ _ _ _ _ _ _ (Miolepidocyclina) panamensis (Cushman) _____________________ _ - _ _ - _ _ _ _ _ - _ X _ _ - _ Upper Member, Gatun Lake Area, Canal Zone (Upper Oligocene) 54. Puma Island, in front of shed near crest of island. Hard calcareous sandstone. S. M. Jones and W. P. Woodring, 1947. Calcareous Sandstone-Siltstone Member. Madden Basin, Panama (Upper Oligocene) 30. Transisthmian Highway, 2 miles in direct line north-north- west of Rio Chagres bridge. Medium-grained calcareous tuifaceous sandstone. W. P. Woodring, 1947. 121. Rio Chilibrillo, 0.4 mile in direct line above bridge on road to Madden Airfield. Coarse-grained poorly sorted calcareous somewhat tufl’aceous sandstone, about 50 feet above base of Caimito formation. W. P. Woodring, 1949. 123, Rio Chilibrillo, 0.6 mile in direct line below bridge on road to Madden Airfield. Medium-grained somewhat cal- careous and somewhat tuffaceous sandstone, about 1,000 feet above base of Caimito formation. W. P. Woodring, 1949. Ouebrsncha Limestone Member, Quebrancha Syncline, Panama (Upper Oligocene) 11a. Quarry of Panama Cement Company, 200 feet north of Transisthmian Highway and 0.9 mile in direct line northwest of highway bridge across Rio Gatuncillo. Middle part of member. J. R. Schultz and W. P. Woodring, 1947. The lithology at locality 53 suggests descriptions of the marl at the submerged locality at Pena Blanca, the type locality for Lepidocyclt'na canellet' Lemoine and R. Douvillé. Locality 43 is reasonably close to U.S.G.S. locality 6021, the type locality of Lepidocy- clina oaugha'ni Cushman. U.S.G.S. locality 6021 is not exposed at present, although it probably could be if the vegetation and mantle debris were cleared away. The Caimito formation contains Miogypsina as well as Eulepidina. Gravell and Hanna (1938, p. 987) proved that the Miogypsina-Heterostegina zone in the Gulf Coast of the United States occurs stratigraphi- cally above the Eulepidina zone. Heterostegt'na ismelskyi and a stellate lepidocycline are index fossils of the zone. Ellisor (1944, pp. 1355—1375) included the Miogypsina- Heterostegina zone of Gravell and Hanna in the Ana— huac formation, a subsurface unit which she placed between “the basal sands of the Fleming above and the subsurface Frio below.” Cole (1938, p. 19) en— countered the Miogypsina-Heterostegina zone in the Port St. Joe test well 3 stratigraphically above beds containing Eulepidina and below beds assigned to the Tampa limestone. Although these beds were referred only to the Oligocene, they should be considered to represent the Suwannee limestone. In other words, their stratigraphic position is above the Byram forma- tion with Lept'docyclina supera. and below the Tampa limestone. The Suwannee limestone is apparently divisible into two zones, the lower one, the Eulepidt'na zone, and the upper one, the Miogypsina-Heterostegtna zone. In these terms the upper part of the Bohio formation in the Pacific coastal area and at least the lower part of the middle member of the Caimito formation in the Gatun Lake area are the stratigraphic equivalents of the Eulepidina. zone of the Suwannee limestone. The remainder of the Caimito formation is the stratigraphic equivalent of the Miogypsina—Heterostegina zone of the Suwannee limestone. . Woodring and Thompson (1949, p. 234) in discuss- ing the upper member of the Caimito formation on Puma Island stated that it contains a small Lepidocy- clina which, on the basis of field identification, was recorded as “probably L. canellei.” The sample from this locality (54) contains only L. yumagunensis. The rest of their field identifications that were checked prove to be correct. EOCENE AND OLIGOCENE LARGER DESCRIPTION OF SPECIES Family LITUOLIDAE Genus YABERINELLA Vaughan, 1928 Yaberinella jamaicensis Vaughan Plate 6, figures 1—8 1928. Yaberinella jamaicensis Vaughan, Jour. Paleontology, vol. 2, pp. 7-12, pls. 4, 5. 1929. Yaberinella trelawniensis Vaughan, idem, vol. 3, pp. 374, 376, pl. 39, fig. 1. The specimens of Yabem'nella jamaicensis from Panama occur in limestone, and it is difficult to obtain specimens from which oriented sections can be prepared. These specimens appear to represent the same species as the one from Jamaica for which Vaughan gives a complete and accurate. description. Although the median section (pl. 6, fig. 6) shows normally a single embryonic chamber, one not centered oblique median section (pl. 6,, fig. 2) has a bilocular embryonic apparatus. The single—chambered em— bryonic apparatus has diameters of 640 by 680 p. The bilocular embryonic chambers are nephrolepidine in type. The initial chamber has internal diameters of 310 by 450 u and the second chamber measures 180 by 480 M. In both the median and transverse sections the initial chamber or chambers are surrounded by a ring of small, square chambers. Topotypes of Y aberinella jamaicensis also possess this feature and are illustrated (pl. 6, figs. 7, 8) for comparison. The largest specimen observed has a diameter of 26 mm. There is considerable range in size, many speci- mens having a diameter of 5 mm or less. Occurrence.——Locs. 131, 131a. Distribution else- where: Middle (as Y. jamm‘censis) and upper (as Y. trelaumiensis) Eocene of Jamaica. Remarks.—Although the diameter of the embryonic chamber is normally about 600 ,u, one specimen has an embryonic chamber with diameters of 820 by 740 ,u. This is approximately the size of the embryonic chamber of the topotype which is figured. The diameters of this chamber are 860 by 680 #- Vaughan (1929, p. 376) in the discussion of the dis- tinguishing features between Y. jamm'censis and Y. trelaumiensis wrote: FORAMINIFERA IN THE CANAL ZONE Very marked differences between the form now described and Y. jamaicensis are not obvious. The initial chamber of Y. trelawniensis seems to be smaller and because the interspaces between the skeletal elements are narrower the internal structure appears finer than that of Y. jamaicensis. Vaughan gave the diameters of the initial chamber of Y. trelaumiensis as 400 by 350 ,u. The specimens from Panama are identical with Y. jamm'censis which Vaughan reports from the middle Eocene Yellow limestone. Y. trelawniensis occurs in the upper Eocene part of the overlying White limestone. Because there seems to be no reliable criterion by which to discriminate Y. jamaicensis from Y. trelawml- ensis, these two species are combined. The stratigraphic range of the combined species is middle and upper Eocene. Family CAMERINIDAE Genus CAMERINA Bruguiére, 1792 Camerina striatoreticulata (L. Rutten) Plate 3, figures 12—20 N ummulities striatoreticulatus L. Rutten, K. Akad. Wetensch. Amsterdam, Proc., vol. 31, pp. 1068—1070, text figs. 41—50, pl., figs. F—J. Camerina sp. Vaughan, Jour. Paleontology, vol. 3, p. 377, pl. 40, fig. 1. ' Camerina petri M. G. Rutten, idem, vol. 9, pp. 530, 531, text fig. 2, pl. 59, figs. 1—5 [not Nummulz'tes petm' Mancini, 1928]. Nummulites striatoreticulatus L. Rutten. Mag, vol. 75, pp. 49—51, pl. 3, figs. 1—5. Camerina striatoreticulata (L. Rutten). Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 31, 32, pl. 8, figs. 5—7. Camerina striatoreticulata (L. Rutten). Cole, Jour. Paleontology, vol. 23, p. 269, pl. 52, figs. 11—13; pl. 55, fig. 7. 1928. 1929. 1935. 1938. Barker, Geol. 1941. 1949. Test biconvex, sloping regularly from the center to the periphery. Slightly weathered specimens have a central mass of clear shell material beyond which there are a few pustules of clear shell material arranged in an irregularly circular manner around the central mass. These pustules occur in the intersutural areas and are elongated radially. They have diameters of 100 by 200 u on the average. Larger and smaller pustules occur. The sutures appear as distinctly raised lines of clear shell material radiating from the center to the periphery. Their course is slightly wavy. llleasurements of sections of Camerina striatoreticulata from locality 140 Median Transverse Specimen . 1 2 l 3 Height ____________________________________________________________ 4.8 mm __________ , 3.6 mm __________ 4.16 mm Width ____________________________________________________________ 4.5 mm __________ , 3.6 mm __________ Thickness-___________________________________________-____-________ __________________§' __________________ 1.5 mm Diameters of initial chamber _________________________________________ 210x 260 ,u _______ l 200x 270 p _______ 260x 240 p. Diameters of second chamber ________________________________________ 100x200 #— _ _ _ __ _v, 100>< 180 ,u. _______ Number of whorls __________________________________________________ 6% _______________ l 5% _______________ Number of chambers in first volution _________________________________ 7 ________________ I ________________ Number of chambers in final volution _________________________________ 21 _______________ ,l 19 _______________ ' Surface diameter of umbonal plug ______________________________________________________ l .................. I 240—400 it FAMILY CAMERINIDAE Occurrence—Loos. 23, 125, 137, 140, 145, 149b. Distribution elsewhere: Upper Eocene of Trinidad, Curacao, Jamaica, and Cuba. Genus OPERCULINOIDES Hanzawa, 1935 Operculinoides fioridensis (Heilprinl 1885. Nummulites floridensz's Heilprin, Nat. Acad. Sci. Proc., Philadelphia, pp. 321, 322, text fig. 1949. Operculinoides floridensis (Heilprin). tology, vol. 23, p. 270, pl. 52, fig. 3. Cole, Jour. Paleon- Specimens which are identical with those reported previously from Panama occur in one sample. Occurrence—Loo 108. Distribution elsewhere: Up- per Eocene of Florida. Operculinoides jacksonensis (Gravell and Hanna) Plate 1, figures 1—9, 20, 21; plate 3, figure 8. 1935. Camem’na jacksonensis Gravell and Hanna, Jour. Paleon— tology, vol. 9, p. 331, pl. 29, figs. 1—5, 7, 8, 10—11, 13, 14. 1939. Camem'na jacksonensis Gravell and Hanna. Barker, U. S. Nat. Mus. Proc., vol. 86, no. 3052, p. 324, pl. 13, fig. 6; pl. 20, fig. 8; pl. 22, fig. 9. ‘ 1942. Camem'na jacksonensis Gravell and Hanna. Cole, Florida Geol. Survey Bull. 20, pp. 26, 27, pl. 8, figs. 3—5. 1945. Camerz’na jacksonensis Gravell and Hanna. Cole, idem, Bull. 28, pp. 101, 102, pl. 13, figs. 3—6. Operculinoides jacksonensis is similar in internal structure and type of aperture to 0. moodybrcmchensis, 9 which has been transferred in this paper from Camer- ina. However, 0. jacksonensis “ is smaller than 0. moodybranchensz's and has beads of clear shell ma— terial developed on the surface of the test, whereas 0. moodybranchensis is unornamented except for an umbonal mass of clear shell material. Operculinoides jacksonensis and 0. kugleri intergrade. Eventually the two species may be combined. How- ever, 0. jacksonensis is more inflated, the beads on the sutures are larger, and the axial plug is more distinct. Occurrence.—~Locs. 108, 149, 14%. Distribution elsewhere: Moodys Branch formation of the Jackson group or its equivalents in Texas, Louisiana, and Mississippi; the Ocala limestone of Florida; the Tan- toyuca formation of the Tampico Embayment. Operculinoides kugleri Vaughan and Cole Plate 3, figures 1—7. 9 1941. Operculinoides kugleri Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 42, 43, pl. 10, figs. 3—5, 7, 8; pl. 13, figs. 1—3. Specimens assigned to Opercuh‘noides kugleri are small, compressed, completely involute and costate, with beads on many of the costae. The outer volution near the apertural end of the test is, normally, extremely compressed, and fragile. Measurements of sections of Operculinoides jacksonensis I Median Transverse E Specimen i 1 1 1 2 2 3 ; 1 4 1 5 1 6 1 7 a 8 ' 1 Height ____________________ 1.5 mm____ 2.1 mm___- 1.32 mm-__-é 1.66 mm__ 1.96 mm__ 2.44 mm__ 2.6 mm--- 1.56 mm Width ____________________ 1.4 mm____ 2.1 mm____ 1.2 mm___-1 ________________________________________ Thickness _____________________________________________________ l 0.6 mm--- 0.82 mm_- 0.9 mm-__ 0.94 mm.. 0.74 mm Diameters of initial chamber- 90 X 80 p- _ _ 80X 70 p- _ _ 70 a _______ i ___________________ .1 ____________________ Diameters of second : chamber ________________ 90x50 1;... 80><50 a--- 80x40 11---; ________________________________________ Distance across both 140;: ______ 130,1; ______ 120p. ______ ; ________________________________________ chambers. ‘ Number of whorls __________ 4% _________ 5% _________ 3% _________ , ________________________________________ Number of chambers in ____________ 8 __________ 8 __________ j ________________________________________ first volution. F Number of chambers in 23 _________ 25 _________ 26 _________ i ________________________________________ final volution. ; Surface diameter of axial ____________________________________ v; 200 a- ___ 220 p.._ __ 260 11.... 240 as _ __ 200 M plug. 1 1 Locality 108. 2 Locality 149. / Aleas'urements of sections of Operculinoides kugleri Median Transverse ° Specimen 1 2 l 3 I 4 5 6 Height _______________________________________ 1.83 mm--- _ 1.74 mm--- 1.57 mm____l 156 mm____ 1.49 mm__ 1.35 mm Width _______________________________________ 1.74 mm___. 1.66 mm____ 1.45 mm____ 1 44 mm____ __________ Thickness ____________________________________________________________________________________ 0.45 mm__ 0.41 mm Surface diameter of axial plug __________________________________________________________________ None- _ _ _ None Diameters of initial chamber ___________________ 40x45 1:... 50x60 MUL 40x40 [1... 80><80 u--- __________ Diameters of second chamber ___________________ 25x50 ,u--- 30X65 u--- 30X50 p--- 45><80 11.--- __________ Distance across both chambers __________________ 75 a _______ 90 p. _______ 75 ,u. _______ 13 ,u. ________________ Number of whorls _____________________________ 5% _________ 5% _________ 5% ________ 4 ____________________ Number of chambers in first volution ____________ 9 __________ 8 ____________________ 9 ____________________ Number of chambers in final volution ____________ 32 _________ 24 _________ ‘ 18 _________ 24 ___________________ l 10 Occurrence—Loos. 149, 14%. where: Upper Eocene of Trinidad. Remarks—The more inflated specimens of Opercu- linoides kugleri intergrade with 0. jacksonensts (Gravell and Hanna) and 0. trinitatensts (Nuttall). However, until a detailed study can be made of a larger suite of thin sections, the three specific names are retained. Distribution else- Operculinoides moodybranchensis (Gravell and Hanna) Plate 1, figures 10—19 1935. Camerina moodybranchensis Gravell and Hanna, Jour. E Paleontology, vol. 9, pp. 332, 333, pl. 29, figs. 15, 22—24. 1939. Camerz'na moodybranchensis Gravell and Hanna. Barker, U. S. Nat. Mus. Proc., vol. 86, no. 3052, pp. 323, 324, pl. 13, fig. 5; pl. 20, fig. 2; pl. 22, fig. 2. EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN‘ THE CANAL ZONE 1941. Camem‘na moodybranchensis Gravell and Hanna. Cole, Florida Geol. Survey Bull. 19, p. 28, pl. 9, fig. 9; pl. 11, figs. 9—15. 1942. Camerina moodybranchens’is Gravell and Hanna. Cole, idem, Bull. 20, p. 27, pl. 8, figs. 6—8. 1945. Camer'ina moodybranchensis Gravell and Hanna. Cole, idem, Bull. 28, pp. 102, 103, pl. 13, figs. 2, 7—9, 12. Although Operculinoides moodybranchensts has been referred to the genus Camerina, detailed study of the well-preserved specimens from Panama demonstrate that it possesses all the characteristics of Operculinoides wilcom' (Heilprin), the genotype of Operculinoides Hanzawa, 1935. Details of the wall structure and the aperture are illustrated on plate I, figure 11. Measurements of sections of Operculinoides moodybranchensis from locality 108 Median Transverse Specimen 1 l 2 1 3 ‘ 4 l 5 l e 7 l 3 Height ................................................... 2.44 mm ..... 2.6 mm ..... 2.8 mm ...... 3.0 mm ...... 3.0 mm ...... 1 3.6 mm ...... 3.5 mm ...... 2 5+ mm Width ___________________________________________ 2.3 mm ...... ‘ 2.5 mm ..... 2.4 mm..._..1 2.7 mm ______ 2.7 mm ______ l 3.36 mm ___________________ Thickness .................................................................. ‘ ............................ i ______________ l .............. 0 9 mm ______ 0 64 mm Diameters of initial chamber .......................... 100x120 14. ._ 80 a ....................... 80x70 p ..... ; 100x90 a. _ ._ 100 u ______________________ Diameters of second chamber ......................... 120x40 a. 80x40 n. I ______________ 110X60 u--.. 100x60 u. ".1 ____________________________ Distance across both chambers ....... 150 u-......-5 120 p ....... l .............. 140 u ________ 160 u ........ “ ______________ 165 u ________ 120+ a Number of whorls ................... 5% .......... I About 5-... t .............. 5% .......... 5 ____________ ‘ About 5 ___________________ Number of chambers in first v01ution... 11 ___________ ‘ .............. ‘ ______________ 8 ____________ I 10 ___________ ‘ ______________ _ ________ Number of chambers in final volution _____ 32 ........... l 27 __________ 30 ___________ ‘ 27 ___________ l 30 ___________ 33 _________________________ Surface diameter of axial plug ............................ ‘ .............. i ........................... ‘ .............. i ____________________________ 300 p ........ 200 p 1 l Occurrence .—~Loc. 108. Distribution elsewhere : external views and thin sections are illustrated to show Moodys Branch formation of the Jackson group or its equivalents in Texas, Louisiana, and Mississippi; the Ocala limestone of Florida; the Tantoyuca formation of the Tampico Embayment. Operculinoides ocalanus (Cushman) Plate 2, figures 5—11 1921. Operculinafocalana Cushman, U. S. Geol. Survey Prof. Paper 128, p. 129, pl. 19, figs. 4, 5. 1941. Operculinoides ocalanus (Cushman).~ Cole, Florida Geol. Survey Bull. 19, pp. 31, 32, pl. 10, figs. 4—7 (references). 1944. Operculinoides ocalanus (Cushman). Cole, idem, Bull. 26, pp. 48, 49, pl. 1, figs. 5, 10; pl. 2, fig. 8; pl. 5, figs. 1, 4—6; pl. 7, figs. 18, 20. . 1949. Operculinoides ocalanus (Cushman). Cole, Jour. Paleon- tology, vol. 23, p. 270, pl. 52, figs. 1, 2. The Panamanian specimens of Operculinoides ocalanus are identical with specimens from Florida. Several the characteristics of this species. Occurrence.—~Locs. 125, 131a, 132, 138a, 140. Dis-y tribution elsewhere: Ocala limestone of Alabama, Georgia, and Florida; the Tantoyuca formation of the Tampico Embayment; the upper Eocene of Ecuador; probably from the upper Eocene of Haiti. Operculinoides panamensis (Cushman) Plate 2, figures 1—4 1919. Nnmmulttes panamensis Cushman, U. S. Nat. Mus. Bull. 103, p. 98, pl. 43, figs. 9, 10. 1941. Operculinoides panamensis (Cushman). Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 46, 47, pl. 10, figs. 13—16; pl. 11, figs. 1—4, and probably fig. 5. Vaughan and Cole redescribed this species from topo— types. The specimens in the present collection resemble the, topotypes. Measurements of sections of Operculinoides panamensis from locality 55 . Specimen 1 l 2 1 3 Height ________________________________________________________ 1 7 mm ____________ i 1 4 mm ____________ 1 74 mm Width _____________________ i ___________________________________ 1 6 mm ____________ I 1 3 mm ____________ Thickness _________________________________________________________________________ ' ____________________ 0.64 mm Diameter of initial chamber _____________________________________ 20 p. _______________ 20 ,u _______________ Diameters of second chamber ____________________________________ 20x30 ,1 ___________ 15x30 ,u. ___________ Distance across both chambers ____________________________________ 45 u _______________ 40 u _______________ Number of coils ________________________________________________ 4% ________________ 4%; ________________ Number of chambers in first volution _____________________________ 8 ______________________________________ Number of chambers in final volution _____________________________ 24 _________________ 20 _________________ Surface diameter of axial plug ________________________________________________________ 1 ____________________ 160—240 .u FAMILY CAMERINIDAE Occurrence.—Loc. 55. Distribution elsewhere: Up- per Oligocene of Trinidad. Operculinoides trinitatensis (Nuttall) Plate 2, figures 17—19; plate 3, figures 9—11 1928. Operculina trinitatensis Nuttall, Geol. Soc. London, Quart. Jour., pp. 102, 103, pl. 8, figs. 10, 11; text figs. 7—9. 1941. Operculinoides trinitatensis (Nuttall). Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 47—50, pl. 10, fig. 12; pl. 13, figs. 4—14. 11 The three specimens of Operculino'ides trinitatensis which illustrate the external appearance have the following measurements: ' Height _________________ ' 2.74 mm- 1.91 mm- 1.82 mm Width __________________ 2.41 mm- 1.71 mm_ 1.7 mm Thickness _______________ 1.16 mm- 0.96 mm- 0.83 mm Costae or septal filaments- 16 _______ 19 _______ 16 The following measurements are from the four thin sections available: Median I Transverse Height ___________________________________________ l 2.3 mm __________ 1.9 mm __________ 5 2.49 mm _________ l 1.82 mm Width____________________“...___________._____; 1.9 mm __________ 19mm __________ i __________________ Thickness _______________________________________ j ____________________________________ I 0.9 mm __________ 1.09 mm Diameter of axial plug ______________________________________________ I ___________________ 1 85 u _____________ None Diameters of initial chamber ______________________ i 50 X 50 u _________ 50X 50 ,u _________ i __________________ Diameters of second chamber-________ _ ___ _- - - - ___ -5 BOX 60 p _________ 30X 50 a ___________________________ Distance across both chambers ____________________ l 86 u _____________ 90 u _______________________________ Number of whorls ________________________________ ‘ 4% _________________________________________________ Number of chambers in first volution _______________ 7 _________________________________ l __________________ Number of chambers in final volution _________________________________ About 15 _________ l __________________ 5 The final volution has been infiltrated so badly that an accurate count of chambers is impossible. Occurrence—Loos. 149, 149b. Distribution else- where: Upper Eocene of Trinidad. Remarks.—The original description and illustrations of this species were not entirely adequate, but Vaughan and Cole studied topotype and other specimens as- signed to this species, giving an expanded description and numerous illustrations. In Trinidad this species is associated with 0. kugler'i Vaughan and Cole, an association which occurs also in Panama. As Vaughan and Cole (1941, p. 50) have noted, “ * * * the more compressed, more costate forms approach 0. kuglem'.” Operculinoides vaughani (Cushman) Plate 2, figures 12—16 1921. Operculina vaughani Cushman, U. S. Geol. Paper 128—E, p. 128, pl. 19, figs. 6, 7. 1935. Operculina vaugham’ Cushman. Gravell Jour. Paleontology, vol. 9, p. 334, pl. 29, 16—21. 1945. Operculinoides vaughani (Cushman). Cole, Florida Geol. Survey Bull. 28, pp. 104, 105, pl. 16, figs. 11—13. The external View of a microspheric and of a mega— lospheric specimen of Operculinoides vaughani are il- Survey Prof. and Hanna, figs. 6. 9, l2, lustrated to demonstrate the differences in surface ornamentation between generations. The microspheric individual has much heavier and more pronounced sutures than does the smaller megalospheric individual. The outer wall of one of the megalospheric specimens (pl. 2, fig. 15) shows canals of the type illustrated by Vaughan and Cole (1936, p. 491, pl. 36, fig. 4a) for 0. vicksburgensis. Occurrence—Loos. 131a, 140. Distribution else- where: Moodys Branch formation of the Jackson group or its equivalents in Texas, Louisiana, Mississippi, and Georgia; the Ocala limestone of Florida. Genus HETEROSTEGINA D’Orbigny, 1826 Heterostegina antillea Cushman Plate 5, figures 1—11 1919. Heterostegina antillea. Cushman, Carnegie Inst. VVashing- ton, Pub. 291, pp. 49, 50, pl. 2, fig. 1b; pl. 5, figs. 1, 2. 1941. Heterostegina antillea Cushman. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p. 54, pl. 15, figs. 10—12; pl. 16. Heterostegina antillea, is characterized by an inflated umbonal area surrounded by a relatively Wide and comparatively thin rim. The embryonic chambers are large and have relatively thick walls. JVIeasurements of typical sections of Heterostegina antillea f Locality , 38 l 39 43 l 45 ‘ Median i Transverse Median Transverse Median Transverse % Median Height ___________________________________________________ i 3.2 mm ...... 3.l6+ mm._ 3.3 mm ______ 2.5+ mm...- 3+ mm ..... 4.2 mm ...... l 3.9 mm ______ i 2.8+ mm Width ________________________ ' ___________________________ i 2.9 mm _______ 2.7+ mm... i .............. 2.1+ mm_._- ______________ 3.8 mm ______ " ______________ : 2+ mm Thickness through center ______________________________________ l _____________ l 0.72 mm.._._ ______________ 1.04 mm _____ Diameter of umbo ................................................. l ............................ 2.0 mm ______ Thickness through flange _________________ _ _______ ! .................. l ____________________________ 0.34 mm _____ Surface diameter of axial plug _____________ _ _______ E ........................... 190 u ______________________ 440—480 a. _ .., Diameters of initial chamber _____________________ 185x220 u... ‘ .............. 195x220 n _________________ 90X110 y. Diameters of second chamber .................... 100x220 14. .. ______________ 140X260 u _________________ 55X130 ,4 Distance across both chambers ________________________ 300 u ________ 325 u ........ 5 ______________ 160 [1 Number of operculine chambers ______________________ l __________________________ Number of coils .......................................... l 2% .......... 2 ............ i‘ .............. 2% 12 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE Distri— and Occurrence—Low. 11a, 37, 38, 39, 43, 45. bution elsewhere: Upper Oligocene of Antigua Trinidad. Heterostegina israelskyi Gravell and Hanna Plate 1, figure 22; plate 4, figure 1; plate 5, figures 12—14; plate 6, ’ figures 17, 18 1937. Heterostegina israelskyi Gravell and Hanna, Jour. Paleon— tology, vol. 11, pp. 524, 525, pl. 62, figs. 1—4. _ 1937. Heterostegina texana Gravell and Hanna, Jour. Paleon- tology, vol. 11, pp. 525, 526, pl. 63, figs. 1~4. 1938. Heterostegina texana Gravell and Hanna. Cole, Florida Geol. Survey Bull. 16, pp. 40, 41, pl. 5, figs. 18~21; pl. 6, figs. 1, 2. 1941. Heterostegina texana Gravell and Hanna. Cole, idem, Bull. 19, p. 33, pl. 10, figs. 8, 9; pl. 11, figs. 1, 2. 1944. Heterostegina texana Gravell and Hanna. Cole, idem, Bull. 26, p. 52, pl. 6, figs. 7—9. 1945. Heterostegina texana Gravell and Hanna. Cole, idem, Bull. 28, pp. 110, 111, pl. 15, figs. 9, 10. Test thin, fragile, with a very small, slightly elevated umbo over the embryonic chambers. Surface of the test unornamented, but slightly weathered specimens show the sutures of the chambers and [the chamberlets. The thickness through the embryonic chambers is about 0.44 mm and the flange thickness is 0.16 to 0.18 mm. In the flange the thickness of the median layer is 60 to 80 p ; each wall of the flange has a thickness of 40 p to 60 it. Average sized specimens have di- ameters of about 6 mm. The embryonic chambers are bilocular, with a thick wall on the side away from the first median chamber and a thin wall on the side adjacent to the first median chamber. Three median sections from locality 110 show the embryonic chambers. The measurements of two of these are in close agree- ment, but those of the third show a'much larger em- bryonic apparatus and a smaller operculine chamber. All of the sections have one operculine chamber following the embryonic chambers. The succeeding chamber is divided into three or more chamberlets. Inone transverse section the distance across both embryonic chambers is 260 ,u and the height of these chambers is 120 .u; in another section the distance across both chambers is 220 a and the height is 180 ,u. The chamberlets are rectangular in shape and vary considerably in size. Certain chambers have radial diameters of 80 11, whereas adjacent ones have radial diameters of 220 u. The tangential diameters of the chamberlets in both of these chambers is about 85 #- 000urrence.—Loc. 55 (rare), 110 (abundant). Dis- tribution elsewhere: Anahuac formation (Heterostegina zone) (Ellisor, 1944, pp. 1355—1375) of late Oligocene age of Texas; the Suwannee limestone of Florida; the Meson formation of the Tampico Embayment. Remarks.—The compressed, fragile test and the small umbo of these specimens are indicative of Hetero— stegz'na israelskyi, but the dimensions of the embryonic chambers are similar to those of H. texana. It is apparent that there is complete gradation between these species, and as the stratigraphic horizon of the type specimens is the same, it would appear that they should be combined. \ Measurements of median sections of Heterostegina israelskyi from locality 110 Specimen 1 2 3 Internal distance across both chambers ___________________________ 230 ,u ______________ 220 a ______________ 320 ,1; Internal diameters of initial chamber ____________________________ 140x 140 p _________ 130x 140 a _________ 180>< 240 11 Internal diameters of second chamber ____________________________ 80X 180 p. __________ 120>< 200 p Thickness of outer wall ________________________________________ _ 20 ,u _______________ 30 [1. Internal diameters of operculine chambers _______________________ 60X 220 p. __________ 60X200 ,u __________ 100x 160 ,u. \ . FAMILY ’CAMVERINIDAE Heterostegina ocalana Cushman Plate 4, figures 2-18 . 1921. Heterostegina ocalana Cushman, U. S. Geol. Survey Prof. Paper 128—E, pp. 130, 131,‘pl. 21, figs. 15—18. 1921. Heterostegina ocalana glabm Cushman, idem, p. 131, pl. 21, fig. 19. , 1941. Heterostegina ocalana Cushman. Cole, Florida Geol. Survey Bull. 19, pp. 32, 33, pl. 11, figs. 3—6. Heterostegina oculana was described by Cushman (1921, pp. 130, 131) from specimens obtained from the Cummer Lumber Company’s phosphate plant no. 6, 1% miles south of N ewberry, Alachua County, Fla. Although the internal structure of this species was not described or illustrated, the photomicrographs of the external appearance are exceptionally clear. Cole (1941, pp. 32, 33) assigned certain specimens from the United Brotherhood of Carpenter and Joiner’s of America, Power House well no. 2, located two miles north of Lakeland, Polk County, Fla, to this species. Five specimens were illustrated, two of which demon~ strated the details of the median section and two the details of the transverse section. In the Panamanian deposits certain specimens resem— ble the description and illustrations of the internal features given by Cole, but other specimens appear to have a larger number of operculine chambers. Therefore, thin sections were made of specimens from the Cummer Lumber Company’s phosphate pit no. 6, collected by Dr. H. G. Naegeli of the Florida Geological Survey, to ascertain the internal features of specimens which would be virtual topotypes of H. ocaltma. Other specimens, collected by Dr. Herman Gunter and the writer from Red Bluff, Flint River, about 7 miles above Bainbridge, Ga., were sectioned also because these specimens were identified by their external appearance as H. oculana. 'The Flofida specunens have fnnn three to seven operculine chambers following the embryonic chambers. These specimens are megalospheric, as one of the speci- mens from Red Bluff (pl. 4, fig. 16) is a microspheric one. This specimen has fifteen operculine chambers. Although most of the specimens from Panama have from 8 to 14 operculine chambers, they are so similar to typical H. ocalana that they may be referred to that species. However, it should be noted that specimens frenilocahty 140 have only two opercuhne charnbers and the embryonic chambers are much larger than any observed in typical H. ocalcma. It is extremely doubtful, however, that a new species should be proposed for these spechnens firnn locahty 140. Because typical specimens of H. ocalana show so much variation at a single locality, it is entirely logical to find marked variation in individuals from different locafitnfi, as food, depth, salnnty, and lflxe factors presumably play an important role in the individual’s development. Measurements of the specimens from Panama, Geor— gia, and Florida follow: 990815~52—3 Measurements of sections of Heterostegina ocalana 13 . B E E 85s a tags: “Sc 3 39§§ 3 N OHO V‘ .11... . 1 . . . .1111. 1 . 1 . 1 a1é111 1 1 1 1 1 1 as - 1 1 1 . E E1§aa§ 1 1 1 1 1 q1awms 1 1 : 1 : "1°~°” 1 1 1 1 1 .1111. 1 . . . 1 111111 1 1 1 1 1 IVEVEI 1 1 I I 1 m . 1 . . 1 1 . a a S1355; 1 1 1 1 1 m . a a 1 1 . s e1$w~$ 1 1 : 1 p N:o'r<'d-¢ 8 1 1 i : s 111111 1 1 1 : 1 e 1. .1. : . . 1 1 5155:; 1 1 1 = 1 1 . 1 “gangs 1 1 1 1 1 N16Adw 1 1 1 1 1 fi :,:.11 . . 1 1 . 111Eg1 i 1 1 3 1 EEEEES 1 1 : 1 1 sass 1 1 1 : 1 1 awwagg 1 1 : l ? NOOHON : : 1 l 1 11.1.1 . . 1 . 1 .11... . . . . . . 111111 1 1 1 1 1 Egg 8611 11 1 8 1 1 1 mac ES. 11: i g 1 1 1 9°31!!! o 3 8 3?: 111115 f i E 3 1 11.111 1 1 1 1 1... 1 1 1 g E21111 3 § i 1 1 : nm1111 x x s 1 1 g asgggg 8 8 H s 4 15 111111 1 1 1 1 1 1,111: 1 a 1 : . E“: 5'31::.1 1: 1 1 1 33 85111: g E i : 1 3n co:11: x x 1 e 0:! ..1111o o 8 x—« g 11:11: 1 1 1 1 1 2 111111 1 1 1 1 1 SE1111 o 8 1 1 1 861111 e g 1 : 1 om1111 1 «agggg s 3 § s § 11111? i i 1 1 1 111.1. 1:. 1 1 1 381111 1 a 1 1 1 553111 ‘ Q S 1 ‘ 1‘6} 1« sagggg § 2 E a a E ::.1.. . 1 . 1 . a 11111? i 1 1 1 1 a BE:':1 1 S 1 1 1 s 381111 1 g 1 1 1 A 5,111.. , sagggg 5 8 § s § 1.11.. 1 . . . . ....1. 1 1 . . 1 111111 ' 1 : ' 1 EE::.: l 3~ 1 l 1 881111 1 8 1 1 1 wm1111 1 x 1 1 : NN:EE; 8 3 3 S a 11111: 1 1 1 1 1 .1.... . 1 . 1 1 1.11. 1 i 1 1 . g 58:11: 1 m 1 1 1 ~ 8111: - w 1 1 1 L"1:111: 2 x 8 1 1 LVN-11:7: no 1°11 1-« co m 1.1... . . 1 1 1 11111: 1 1 1 1 1 aé1111 1 1 1 . 1 ‘38:..; :8 l ' i gm:111 ; x 1 1 : N&::E§ w 3 8 s a 1.1.1. . . . 1 . 1111:: 1 i 1 1 Ediiii S 8 ‘ E 85111: g g 1 1 1 NH 1. 1 sagggg s S 5 5 § § 11111: 1 1 1 1 1 11:11: i i 1 1 1 a ::1: 1 1 1 3311?: § § 1 i l 1 . . IOC":: "‘ Naggl: 5 3 g I § 1.... a 1 111113 e g i g 1 111:1x s o o _ 1 111.153 .1.1 o Q -—~ . 11111a = o = ' ::::.o ... w m 2 : 111°gn a u 2 w 1 11.19:,2 o o 1- 54 m‘ :11ESw o o : 111:1,“a 2 1014‘” 1.. 8 .fi . . . 1:11:05} ogggvachgu 11%hfi'c ~A-7@<—w 00"“09 '12329.°3w§19335 Esawxowsfianwfiggn “3.28.233mfie012; :E '$~~:.S:EQ-~ou—1 ".953: mgenem Q m a z z 14 Occurrence—Lees. 22a, 125, 140. .Distribution else- where: Ocala limestone of Florida and Georgia. Heterostegina panamensis Gravell Plate 5, figures 15~19 1933. Heterosteginq panamensis Gravel], Smithsonian Misc. 0011., vol. 89, no. 11, pp. 17, 18, pl. 1, figs. 10, 11. The specimens of Heterostegina panamensis from Panama are slightly thicker through the center than the type specimens from Venezuela. The type speci- mens have four operculine chambers, whereas those in the present collection have one or two. As these differences are slight, the specimens from Panama are referred to this species. Occurrence—Loos. 11a, 55. Distribution elsewhere: San Louis limestone of late Oligocene age in Venezuela. Remarks—This species is a small, more or less evenly biconvex one with a very pronounced axial plug. Family AMPHISTEGINIDAE Genus HELICOSTEGINA Barker and Grimsdale, 1936 Helicostegina soldadensis Grimsdale Plate 6, figures 9—12 1941. Helicostegtna soldadensis Grimsdale, Geol. Soc. America Spec. Paper 30, pp. 77, 86, 87, pl. 45, fig. 4; pl. 46, figs. 1—7. The specimens of Helicostegtna soldadensis from Panama are identical with the types from central Trinidad and Soldado Island. Moreover, the associa- tion of other species with it is nearly the same. EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE Occurrence—Lac. 22a. Distribution elsewhere: Up- per Eocene of Trinidad and Soldado Island. Family CYMBALOPORIDAE Genus FABIANIA A. Silvestri, 1926 Fabiania cubensis (Cushman and Bermudez) Plate 6, figures 13—16 1936. Pseudorbitolina cubensis Cushman and Bermfidez, Cush- man Lab. Foram. Research Contr., vol. 12, p. 59, pl. 10, figs. 27—30. 1944. Eodtctyoconus cubensis (Cushman and Bermfidez). Cole and Bermudez, Bull. Am. Paleontology, vol. 28, no. 113, pp. 336—340, pl. 27, fig. 1; pl. 28, figs. 1—12; pl. 29, figs. 1—5 (references). Test plano-convex with a deeply excavated umbilieus on the ventral side. An average specimen of Fabiam'a cubensis has a diameter of 1.2 mm; a height of 1.0 mm; and the umbilicus has a diameter of 0.6 mm. The dorsal surface is covered by a reticulate mesh formed by the sutures of the chambers and chamberlets. Occurrence—Low. 15, 22a, 131, 131a, 138a, 140, 1491). Distribution elsewhere: Middle Eocene of Cuba and Florida. Remarks—There does not appear to be any reliable feature on which to distinguish the Panamanian speci- mens from the type specimens from Cuba. In Cuba this species occurs with typical middle Eocene species, such as, Dictyoconus americanns (Cushman) and Gun- teriar flortdana, Cushman and Ponton. In Florida this species is found in sediments assigned to the middle Eocene (Cole, 1944, p. 36). However, in Panama it is associated with definite late Eocene species. Measurements of sections of Heterostegina panamensis Locality 11a 55 Median l Transverse Median Transverse Height _______________________________________________ 2.4 mm ________ 2.5 mm ________ 1 8 mm ________ 1.84 mm Width__-__‘ ___________________________________________ 2.1 mm ________________________ 1 7 mm ________ Thickness _____________________________________________________________ 1.06 mm _______________________ 0.92 mm Surface diameter of axial plug ___________________________________________ 580 ,u __________________________ 520 ,u. Diameters of initial chamber ____________________________ 130>< 140 ,4 _____________________ 115x 125 n _____ Diameters of second chamber ____________________________ 80X 185 p. ______ ‘ ________________ 60X 180 M ______ Distance across both chambers __________________________ 220 p __________ 215 ,u. __________ 185 p __________ 220 a Number of operculine chambers _______________________________________________________________________ Number of coils _______________________________________ 2% ____________________________________________ Measurements of sections of Helicostegina soldadensis from locality 22a 1 Median Transverse Diameter ___________________________________________________ 0.8 mm ______ 1.4 mm ______ 1.2 mm ______ 0.9 mm Thickness _____________________________________________________________________________________________ 0.46 mm Number of coils in spire ______________________________________ 3+ __________ 3% __________ 4 ____________ Number of chambers in last coil _______________________________ 22 ___________ 22 ___________ 27-"; _______ Internal diameters of initial chamber ___________________________ 75X80 a _____ 80X 70 u _____ 40><40 u _____ 80><80 u Internal diameters of second chamber __________________________ 30X80 p _____ 20X 30 u _____ 20x40 ,u _____ 30x50 [1. Internal diameter of both chambers ____________________________ 110 p ________ 100 u ________ 80 u _________ 125 in Wall thickness of initial chamber ______________________________ l 20 p. _________ 20 u _________ 20 p _________ 20 [1. Dimensions of flange chamberlets: ' _ Radial diameters _______________________________________________________ 20—40 ,u ______ 20—50 ,u ______ Tangential diameters ___________________________________________________ 50—80 M ______ 20—80 u ______ FAMILY ORBITOIDID AE I Family ORBITOIDIDAE Subfamily LEPIDOCYCLINAE Tan Genus LEPIDOCYCLINA Giimbe], 1870 Subgenus PLIOLEPIDINA H. Douvillé, 1917 Lepidocyclina (Pliolepidina) gubernacula Cole, n. sp. Plate 8, figures 9—14; plate 9, figures 1, 2; plate 12, figure 16; plate 20, figure 17 ; plate 23, figure 13 Megalospheric generation—Test of medium size from 8.5 to 10 mm in diameter, disc-shaped. The central area is very slightly inflated and is bounded by a thinner portion beyond which the test thickens into a distinctly elevated rim at the periphery of the test. The edge of the test is corrugated, the individual ridges of which are the eroded walls of the equatorial chambers. The shape of the equatorial chambers in plan View can be ascertained for a short distance inward from the ‘15 pillars over the central portion, but slightly weathered specimens have distinct, small pillars with diameters of about 100 u, evenly scattered over the central area. Neither type appears to have pillars in the depressed zone or on the inflated rim. The embryonic chambers are large, thin-walled, bilocular; the initial chamber is larger than the second chamber. Normally, there are two large periembryonic chambers, one at each end of the dividing partition between the embryonic chambers. A well-developed periembryonic chamber has internal diameters of 140 by 460 u. The equatorial chambers as viewed in equatorial section are larger near the center of the test and de— crease in size toward the periphery. The normal shape of these chambers is rhombic, but some have curved periphery, as the equatorial chambers at the margin of the test are not covered by lateral chambers. The low, slightly inflated central portion of the test is covered by a reticulate mesh formed by the walls of the lateral chambers. The development of pillars is outer walls and pointed inner ends. The equatorial layer expands regularly toward the The outer 0.5 mm of the equa— periphery of the test. torial layer is not covered by lateral chambers; therefore these chambers comprise the entire thickness of the test variable. Unweathered spe01mens have low, indlstlnct ‘ 1n thlS zone. Illeasurements of equatorial sections of Lepidocyclina (Pliolepidina) gubernacula from locality 23 Specimen 1 ; 2 3 Diameter ____________________________________________________ 7.8 mm ____________ i 5.9 mm ____________ 7.4 min Embryonic chambers: 5 Diameters of initial chamber _______________________________ 600x940 ,u _________ 1 670x940 u _________ 680><840 ,u Diameters of second chamber ______________________________ 480x 960 u _________ l 360>< 660 u _________ 340x780 ,u Distance across both chambers _____________________________ 1100 u _____________ l 1050 p. _____________ 1040 u Thickness of outer wall ____________________________________ 20—30 M. - _ _ _ _ - _ _ _ _ —i 18 u _______________ 20—30 In Equatorial chambers: . Near center: ‘ Radialdiameter"_1~____________-_______1__‘_ _________ 170p ______________ 1 140a ______________ 160p. Tangential diameter __________________________________ 160 ,u ______________ l, 160 ,u ______________ 160 pt Near periphery: ~ 1 Radial diameter ______________________________________ 120 pt ______________ 1 120 u ______________ 100 ,u Tangential diameter __________________________________ 140 [.4 ______________ 120 p. ______________ 140 p JIeasurements of vertical sections of Lepidocyclina (Pliolepidina) gubernacula from locality 23 Specimen 1 2 3 Diameter ____________________________________________________ ‘ 9.6 mm ____________ 8.6 mm ____________ 8.6 mm Thickness at center ___________________________________________ 0.92 mm ___________ 1.66 mm ___________ 1.08 mm Thickness at periphery ________________________________________ 0.6 mm ____________ 0.6 mm ____________ 0.68 mm Thickness 0.8 mm from periphery ______________________________ 0.48 mm ___________ 0.46 mm ___________ 0.54 mm Thickness 2 mm from periphery ________________________________ 0.62 mm ___________ 0.64 mm ___________ 0 7 mm Embryonic chambers: Length _______________ . ___________________________________ 600 u ______________ 900 M ______________ 800 It Height __________________________________________________ 440 u ______________ 540 u ______________ 600 a Thickness of outer wall ____________________________________ 20 u _______________ 35—40 M ____________ 25 y. Equatorial layer: Thickness at center _______________________________________ 200 a ______________ 220 u ______________ 200 [1 Thickness at periphery ____________________________________ 600 p. ______________ 600 u ______________ 680 u Thickness 0.8 mm from periphery __________________________ 310 p. ______________ 360 p ______________ 400 u Thickness 2 mm from periphery ____________________________ 240 ,u ______________ 280 p ______________ 300 p. Lateral chambers: Number on each side of the embryonic chamber ___________________________________________________ 5 ~1 Length __________________________________________________ 120—160 y. __________ 80—300 p. ___________ 160-280 M ‘ Height ___________________________________________________ 30 u _______________ 40—50 M ____________ 20—30 g Thickness of floors and roofs _______________________________ 20' u _______________ 20—30 a ____________ 15 [1. Surface diameter of pillars _____________________________________ 60 p _______________ 100-140 In __________ 60 u 16 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE The lateral chambers are not arranged in regular tiers. These chambers are relatively long, low, but with open, distinct ,cavities. The floors and roofs are rela- tively thin. The floors and roofs are either straight or slightly convex toward the outside of the test. The number of lateral chambers to a tier decreases regularly toward the periphery 'of the test, but the peripheral zone of the test is devoid of lateral chambers. Thin, cylindrical pillars occur irregularly in the cen- tral area of the test, but decrease in size and distribution toward the periphery. Microsphem'c generationw—Test large, having a di- ameter of 20 mm or more. There is a distinct central umbo which is bordered by a thinner area which in turn is surrounded by an elevated rim. The inflated central portion has distinct, slightly elevated papillae which become smaller and more scattered toward the edge of the test which is devoid of papillae. The vertical section (pl. 23, fig. 13) adequately illustrates the internal features of this type of section. A fragment from the same specimen from which the vertical section was made shows equatorial chambers of the same type as those possessed by the megalospheric individuals. These chambers have thicker walls than those of the megalospheric generation and are slightly larger in size. Holotype: U.S.N.M. 561091; paratypes: U.S.N.l\l. 561052, 561053, 561055. Occurrence—Lee. 23. Remarks—The distinctly elevated rim of the test is a characteristic feature of this species externally. No other American species from the Eocene possesses this feature. Lepidocyclina (L.) novitasensis and L. (L) meinzer'i from the Eocene of Cuba have rather large embryonic and rhombic equatorial chambers but these two species are very different in vertical sections. ‘ Specimens identified as L. (L.)rsp. aff. L. ocalcma pseudocarinata Cushman by Vaughan and Cole (1941, p. 68, pl. 31, figs. 10, 11) most certainly are L. guber- nacula. The specimens from Trinidad have rhombic— shaped equatorial chambers, whereas all the forms of L. ocalanc have arcuate to short-spatulate equatorial chambers. Moreover, the vertical section illustrated by Vaughan and Cole shows the rapid expansion of the equatorial layer in the peripheral zone which is char- acteristic of L. gubernacula. Three small specimens (pl. 8, figs. 9—11) were found at locality 22a. At first these specimens were thought to constitute a distinct species, but detailed study demon- strates that they are probably small individuals of this new species. If size is disregarded, the main difference between these specimens and the typical specimens from locality 23 appears in the shape of the equatorial chambers. Although many of the chambers in the specimens from locality 22a are rhombic, those near the periphery become spatulate. However, the fundamental pattern is the same in the specimens from both localities, as some of the rhombic chambers in the specimens from locality 23 tend toward the spatulate. Lepidocyclina (Pliolepidina) macdoualdi Cushman Plate 7, figures 1—19; plate 8, figures 1—4; plate 14, figure 11; probably plate 20, figure 16 1919. Lepidocyclina macdonaldi Cushman, U. S. NatuMus. Bull. 103, p. 94, pl. 40, figs. 1—6. 1933. Lepidocyclma (Lepidocyclina) macdonaldi Cushman. Gravell, Smithsonian Misc. Coll., vol. 89, no. 11, pp. 25, 26, pl. 5, figs. 1—3. [Probably not fig. 2 which appears to be L. pustulosa H. Douvillé.] , 1941. chidocyclina (Pliolepidina) macdonaldi Cushman. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p. 67, pl. 31, figs. 1, 2. 1945. Lepz’docyclina (Pliolepidina) macdonaldi Cushman. Cole, Florida Geol. Survey Bull. 28, pp. 117—120, pl. 19, figs. 1—13. Typical specimens of Lepidocyclina (Pliolepidina) macdonaldi were found in most of the Eocene samples examined. The vertical section shows the equatorial layer expanding regularly toward the periphery. The lateral chambers have low cavities between thick roofs and floors. Occurrenceerocs. 15, 124, 125, 131, 131a, 138a, 140, 145, 149, 149b, 150. Distribution elsewhere: Upper Eocene of Trinidad, Venezuela, the Tampico Embay- ment and the State of Chiapas, Mexico, Jamaica, and as reworked specimens in the Oligocene of Florida where it occurs with reworked middle Eocene species. Lepidocyclina (Pliolepidina) pustulosa H. Douvillé Plate 13, figures 1—20; plate 14, figures 1—10; plate 15, figures 14—16; plate 20, figures 14, 15; plate 23, figures 1—3, 10 Isolepidina pustulosa H. Douvillé, Paris Acad. Sci., C. R., vol. 161, p. 844, text figs. 1—4. Orthophragmina hayesi Cushman, U. S. Geol. Survey Prof . Paper 125, p. 43, pl. 8, figs. 8—10. 1917. 1919. 1928. Lepidocyclina subglobosa Nuttall, Geol. Soc. London, Quart. Jour., vol. 84, p. 104, pl. 7, figs. 3, 5—7. 1941. Lepidocyclina (Pliolepidz'na?) subglobosa Nuttall. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 67, 68, pl. 31, figs. 8, 9. 1941. Lepidocyclina (Pliolepz’dina) pustulosa H. Douvillé. Vaughan and Cole, idem, pp. 65, 66 (references and synonymy). 1949. Lepidocyclina (Pliolepidina) pustulosa H. Douvillé. Cole, Jour. Paleontology, vol. 23, p. 272, pl. 54, fig. 5; pl. 55, fig. 8. A great number of different specific names have been applied to individuals of Lepidocyclina (Pliolepidinc) pustulosa H. Douvillé which possess the same basic features, but differ from one another in shape, size, or other minor elements. Vaughan and Cole (1941, p. 65) have demonstrated that these names should be suppressed. The sample from locality 140 contained many in- dividuals which represent this species. A series of I seven vertical sections (pl. 13, figs. 5, 8—10, 12, 14, 16) demonstrate the extreme variability of individuals of FAMILY ORBITOIDIDAE 17 this species from one another in one sample. But, the essential features of all are the same. It is apparent from the study of many thin sections that L. subglobosa N uttall represents small specimens of L. pustulosa. The features of the equatorial and vertical sections are the same. Although Vaughan and Cole retained L. subglobosa as a distinct species in their report on the larger Foraminifera of Trinidad, the suite of thin sections available now demonstrates that L. subglobosa is L. pustulosa. Orthophragmina hayesi Cushman from the Brito formation of Nicaragua was shown by Vaughan (1924, p. 790) to be a Lepidocyclina with rhomboid equatorial chambers. The vertical sections of the Nicaraguan specimens are similar to specimens in Panama (pl. 13, fig. 19) which are referred to L. pustulosa. There is little doubt that L. hayesi is L. pustulosa. Occurrence.—Locs. 15, 22a, 124, 131, 131a, 137, 138a, 140, 149, 149b, 150. Distribution elsewhere: Upper Eocene of the Isthmus of Tehuantepec and Rio Vinazco, Chieontepec, state of Veracruz, Mexico; Jamaica; Panama; Curacao; Venezuela; Nicaragua; and from the middle Eocene of Florida. Iepidocyclina (Pliolepidina) pustulosa tobleri H. Douvillé Plate 13, figure 21; plate 14, figures 12, 13; plate 15, figures 17—21 1917. Pliolepidina tobleri H. Douvillé, Paris Acad. Sci., C. R., vol. 164, p. 844, text figs. 5, 6. Lepidocyclina panamensis Cushman, U. S. Nat. Mus. Bull. 103, pp. 94, 95, pl. 39, figs. 1—6; pl. 42. Lepidocyclina duplicate Cushman, idem, p. 96, pl. 41, figs. 2—4. Pliolepidina tobleri H. Douvillé. H. Douvillé, Soc. Géol. France Mém., n. 5., vol. 1, no. 2, pp. 43, 44, text figs 34, 35. Lepidocyclz'na (Polylepidina) zuliana H. Hodson, Bull. Am. Paleontology, vol. 12, no. 47, pp. 25, 26, pl. 7, figs. 1—3. Lepidocyclina (Polylepidina) mirandana H. Hodson, idem, pp. 26, 27, pl. 7, figs. 4—6. Lepidocyclina curasam'ca Koch, Eclogae geol. Helvetiae, vol. 21, pp. 54—56, pl. 3, figs. 1—5. Lepidocyclina (Pliolepidina) tobleri H. Douvillé. L. Rutten, K. Akad. Wetensch. Amsterdam, Proc., vol. 31, p. 1067. text figs. 19—35, pl. figs. 0, D. Lepidocyclina sp. afl’. ? Polylepidina proteiformis Vaughan. L. Rutten, idem, p. 6, pl. fig. E [not Lepidocyclina (Polylepidina) proteiformis Vaughan, 1924]. Lepidocyclina (Pliolepidina) tobleri H. Douvillé. Rutten and Vermunt, idem, vol. 35, pp. 12, 13, pl. 1, fig. 5; pl. 2, figs. 3, 7, 8. ’ Lepidacyclina curasavica Koch. Rutten and Vermunt, idem, p. 8, pl. 1, figs. 1, 2; pl. 2, fig. 5. Lepidocyclina (Pliolepidina) pustulosa forma tobleri H. Douvillé, forma teratologica. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 66, 67, pl. 24. Lepidocyclina (Pliolepidina) pustulosa forma tobleri H. Douvillé, forma teratologica. vol. 23, p. 272, pl. 52, fig. 4; pl. 54, fig. 9. Several equatorial and horizontal sections of Lepido- cyclina (Pliolepidina) pustulosd 'tobleri H. Douvillé are 1919. 191.9. 1924. 1926. 1926. 1928. 1928. 1928. 1932. 1932. 1941. 1949. Cole, J our. Paleontology, _ illustrated to show the individual differences which may occur. Vertical sections are particularly variable. The equatorial chambers have the same shape and pattern as do those of typical L. pustulosa H. Douvillé. Although this form is so closely related to L. pustulosa that specific discrimination is not possible, it can be questioned that it is a teratologic type. The so-called abnormal embryonic chambers may be a normal tendency in this particular race (Woodring, 1927). Occurrence.—L0cs. 108, 124, 131a, 132, 138a, 145, 149b. Distribution elsewhere: Upper Eocene of Cu- racao; Rio Vinazco, Canton of Chicontepec, Veracruz, Mexico; Trinidad. Remarks—Cushman (1919a, p. 90) tentatively (and incorrectly) recorded this species under the name L. panamensz's in the‘Culebra formation and the Emperador limestone. ' Subgenus LEPIDOCYCLINA Giimbel, 1870 Lepidocyclina (Lepidocyclina) asterodisca Nuttall Plate 17, figure 4 1932. Lepidocyclina (Lepidocyclina) asterodisca N uttall, Jour. Paleontology, vol. 6, pp. 34, 35, pl. 7, figs. 5, 8; pl. 9, fig. 10. Lepidocyclina (Lepidocyclina) falconensis Carter and van der Vlerk, Leidsche Geol. Meded., vol. 4, pp. 105, 106, pl. 11, figs. 4—6. 1937. Lepidocyclina (Lepidocyclina) texana Gravell and Hanna, Jour. Paleontology, vol. 11, pp. 527—529, pl. 65, figs. 1—7. Lepidocyclina (Lepidocyclina) asterodisca Nuttall. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p 73, pl 39, figs 3, 4. , Although the sample from which the specimen as- signed to Lepidocyclina, (Lepidocyclina) asterodisca contains abundant specimens of Heterostegina, only one specimen of L. (L.) asterodisca was found. A description of this specimen follows: Test stellate with five rays which radiate from a central umbo. The umbo has a diameter of about 2.1 mm. The rays are narrowest at their juncture with the umbo and widen as they approach the periphery of the test. The interray areas are flat. The diameter of the test is about 7.8 mm. The equatorial chambers are arranged in conformity with the stellate pattern of the test. These chambers are short-spatulate in shape with radial diameters of 100p. and tangential diameters of 80p. Occurrence—Loo. 110. Distribution elsewhere: As L. asterodisca from the Alazan formation of the Tampico Embayment and the upper Oligocene of Trinidad, from the Anahuac formation of Texas as L. texana, and from the Churuguara series of central Falcon, Venezuela, as L. falconensis. Remarks. —L. asterod’ésca was described from speci- mens obtained in the Alazan formation of the Tampico Embayment area. Later, Vaughan and Cole (1941, p. 73) assigned specimens from three localities in 1932. 1941. 18 Trinidad to this species. Vaughan and Cole noted that L. asterodtsca is very close to L. texana Gravell and Hanna (1937, pp. 527, 528). Gravell and Hanna separated their species from L. asterodisca by its larger size and its possession of five instead of four rays. Because there is considerable variation in such characters in other species of Lepido- cyclina, these species are combined. In Trinidad L. asterodisca is associated with Heter- ostegina antillea, Lepidocyclina (Lepidocyclina) parvula, L. (L.) yurnagunensis, L. (Nephrolepidtrta) tempanit, and L. (Eulepidina) undosa. In Texas L. asterodisca is associated with new species of Operculinoides, Heter— ostegina, and Lepidocyclina. In Panama L. asterodisca occurs with abundant specimens assigned to Heter- ostegina israelskyi, one of the species with which it occurs in Texas. Lepidocyclina (Lepidocyclina) canellei Lemoine and R. Douvillé Plate 16, figures 1—22; plate 17, figures 1—3 1904. Lepidocyclina canellei Lemoine and R. Douvillé, Soc. Geol. France Mém,. vol. 12, p. 20, pl. 1, fig. 1; pl. 3, fig. 5. 1919. Lepidocyclina canellei Lemoine and R. Douvillé. Cush— man, U. S. Nat. Mus. Bull. 103, p. 91, pl. 34, figs. 1—6. 1920. Lepidocyclina canellei Lemoine and R. Douvillé. Cush- man, U. S. Geol. Survey Prof. Paper 125, p. 75, pl. 32, figs. 1—5: 1924. Lepidocyclina (Lepidocyclina) canellei Lemoine and R. Douvillé. Vaughan, Geol. Soc. America Bull., vol. 35, pp. 797, 819, pl. 33, fig. 4. 1928. Lepidocyclina (Lepidocyclina) canellei Lemoine and R. Douvillé. Vaughan, Jour. Paleontology, vol. 1, p. 290, pl. 49, figs. 1—5, 7—9. EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE 1932. Lepidocyclina (Lepidocyclina) pancanalis Vaughan and Cole, Jour. Washington Acad. Sci., vol. 22, pp. 510— 514, figs. 1—9. , Lepidocyclina (Lepidocyclina) canellei Lemoine and R. Douvillé. Vaughan, Smithsonian Misc. Coll., vol. 89, no. 10, pp. 14, 15, pl. 6, figs. 1—5. Lepidocyclina (Lepidocyclina) canellet Lemoin'e and R. Douvillé. Gravell, idem, vol. 89, no. 11, pp. 24, 25, pl. 5, figs. 4—8. Lepidocyclina (Lepidocyclina) canellei Lemoine and R. Douvillé. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, pp. 70, 71, pl. 35, figs. 6, 7; pl. 41, figs. 4, 5. 1941. Lepidocyclina (Lepidocyclina) pancanalis Vaughan and Cole, idem, p. 71, pl. 35, figs. 8, 9, 1933. 1933. 1941. Two closely related species, Lepidocyclina (L.) canetlei Lemoine and R. Douvillé and L. (L.) pancanatis Vaughan and Cole, have been described from the Oligo- cene of Panama. Vaughan and Cole stated: L. canellei is usually larger, but the senior author has speci- mens of a dwarf variety from Arbol Grande, near Tampico, Mexico. In L. canellei the ratio of the diameter to thickness is greater, and in perfectly preserved specimens there is a distinct flange which may be peripherally thickened. L. canellei lacks the pillars and the thickened surface papillae and costulations of L. pancanalis. The equatorial chambers of L. canellei are strik- ingly regular hexagonal in shape, while those of L. pancartalis are dominantly of diamond or short-spatulate form. Certain specimens in the present collection were recognized immediately as L. canellei and others were assigned to L. pancanalis. Other specimens \ap- peared to be intermediate between the two species. An equatorial section and two vertical sections were made of topotypes of L. pancanalts. Measurements of these follow: Measurements of equatorial sections of topotype and holotype of Lepidocyclina (L.) pancanalis ! Topotype Holotype [after Vaughan and Cole, 1932] l Diameter __________________________________ i 1.5 min ____________________________ 1.5—2.0 mm Embryonic chambers: Distance across both chambers ___________ 220 u ______________________________ 185 p. Maximum width ________________________ 180 p ______________________________ 145 u Thickness of outer wall __________________ 20 u _______________________________ 25 p. Equatorial chambers: Radial diameter ________________________ 20—60 ,u ____________________________ 60 a Tangential diameter _____________________ 20—40 p. ____________________________ 50 [.4 Shape _________________________________ Rhombic, short—spatulate, hexagonal___ Rhombic, short-spatulate, hexagonal Measurements of vertical sections of topotypes and holotype of Lepidocyclina (L.) pancanalis ‘ r n ”W ”’65 ind 00125932] Diameter ____________________________________________________ 1.6 mm ____________ 1.5 mm ____________ 1.5—2.0 mm Thickness ___________________________________________________ 0.8 mm ____________ 0.7 mm ____________ 0.75—1.0 mm Embryonic chambers: Length __________________________________________________ 180 u ______________ 180 p ______________ 185 p Height ________ , __________________________________________ 160 p. ______________ 160 u ______________ Thickness of outer wall ____________________________________ 30 u _______________ 40 a _______________ 25 114 Equatorial layer: Height at center __________________________________________ 70 u _______________ 60 u _______________ Height at periphery _______________________________________ 80 p _______________ 80 p _______________ Lateral chambers: Number ___________________________________________________________________ 6 __________________ 10 Length __________________________________________________ 70—95 a ____________ 60—90 [J ____________ 60 [1. Height _____________ . ____________________________________ 35 p _______________ 40 p _______________ 40 ,1: Thickness of floors and roofs _______________________________ 8 a ________________ 7 ,u ________________ Surface diameter of pillars _____________________________________ 60 p _______________ 50—60 u ____________ Present FAMILY ORBITOIDID AE 19 Measurements of equatorial sections of specimens from locality 53 assigned without question to Lepidocyclina canellei ; Specimen 1 2 3 Diameter __________________________________________ 3 4 mm _____________ 3.1 mm _________ 2.6 mm Embryonic chambers: Distance across both chambers ___________________ 260 n ______________ 280 u __________ 200 u Maximum width _______________________________ 220 u ______________ 240 ,u __________ 160 u Thickness of outer wall _________________________ 20—40 a ____________ 20—30 u ________ 30 p. Equatorial chambers: Radial diameter ________________________________ 60-7 M _____________ 70—80 a ________ 60—80 M Tangential diameter ____________________________ 60—80 ____________ 60—80 M ________ 40—60 a Shape _________________________________________ Short-spatule _______ Hexagonal ______ Rhombic, short-spatulate, hexagonal Measurements of vertical sections of specimens from locality 53 assigned without question to Lepidocyclina canellei Specimen l 2 3 4 5 6 7 Diameter __________________________________ 3.3 mm- _ 3.1 mm 3.3 mm_ - 3.06 mm- 2.2 mm-- 2.0 mm- - 1.7 mm Thickness __________________________________ 0.92 mm- 0.96 mm- 0.76 mm- 1.0 mm- - 0.98 mm- 0.92 mm- 0.92 mm Width of flange _________________________________________________ 0.16 mm- 0.2 mm- - ____________________ Embryonic chambers: , 7 Length ________________________________ 220 u_--- 280 11---- 220 [.t-_-_ 180 u--_- 200 p-_-- 180 p.-_-- 180p. Height ________________________________ 190 n---- 240 ,u-_-_ 220 [.t__-_ 180 ,u.____ 170 p____ 180 p._-__- 120p Thickness of outer wall __________________ 40 p _____ 50 u _____ 20—40 ,u- _ 30 ,u _____ 20-30 M— _ '20 u- _ ;_- 20 ,u. Equatorial layer: Height at center ________________________ 80 u _____ 80 u _____ 80 [t _____ 80 u _____ 65 p. _____ 70 p. _____ 70 u Height at periphery _____________________ 140 ,u--_- 140 #—-—— 160 #—--— 140 n__-- 120 M--- 120 #-——— 100p Lateral chambers: Number _______________________________ 12 ________ 9 ________ 9 ________ 10 _______ 10 _______ 10---.--_- 10 Length ________________________________ 60—120 M- 60—80 u__ 60—80 p,_- 60—80 [1.-- 60—140 p 60—110 p- 40—80 a Height ________________________________ 40 u _____ 30—40 ,u._ - 20—30 p- - 30—40 11- - 30—40 [1. - 20—40 p- _ 35—40 M Thickness of floors and roofs _____________ 6 ,u ______ 8 p. ______ 6 u ______ 7 u ______ 8 .u ______ 5—8 a. _ -- 8 u Surface diameter of pillars ___________________ None- - - - None. - _ - None- - _ _ None- _ _ _ None- - - _ None- - - - None The greatest difference between the specimens of L. L. pancanalis and their apparent absence in L. canellei. pancanalis and L. canellei is the presence of pillars in In other features there is a striking similarity. Measurements of specimens of Lepidocyclina canellei from localities other than no. 53 Equatorial sections Specimen l 1 a 2 a 3 l 4 Diameter _________________________ 1 9 mm- - .. _________ 2.94 mm ______________ 2 9 mm _____________ 2.2 mm Embryonic chambers: Distance across both chambers--- 195 n -------------- 260 p ---------------- 230 u -------------- 230 [4 Maximum width --------------- 175 u -------------- 220 [1. ---------------- 200 u -------------- 185 u Thickness of outer wall --------- 20—35 [4 ------------ 20—30 It -------------- 20—30 a ------------ 30 ,u Equatorial chambers: Radial diameter ________________ 40—60 ,1; ------------ 50—70 H -------------- 80 u --------------- 80 u Tangential diameter ------------ 40—60 -- ---------- 50—60 a -------------- 60 u --------------- ,1; Shape ------------------------ Short-spatulate ------ S _h o r t - s p a t u l a t e , Short-spatulate- - --- - - Short-spatulate hexagonal 2O EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE Measurements of specimens of Lepidocyclina- cancellei from localities other than no. 53—Continued Vertical sections Specimen 1 1 2 2 2 3 a 4 a 5 Diameter _______________________________________________ 2.44 mm____ 2.6 mm _____ 2+ mm____ 2.2 mm _____ 2.8 mm Thickness _______________________________________________ 1.1 mm _____ 1.1 mm _____ 1.26 mm__,_ 1.1 mm _____ 1.04 mm Width of flange __________________________________________ 0 2 mm _____ 0.14 mm____ ____________ 0.14+ mm- Embryonic chambers: Length _____________________________________________ 160 [z ______ 220 p ______ 220 a ______ 200 p ______ 240 ,u Height _____________________________________________ 180 ,u ______ 180 n ______ 160 u ______ 180 n ______ 210 ,u. Thickness of outer wall _______________________________ 20—30 H. _ _ _ 20—40 ,u- _ _ _ 20 p. _______ 20—50 u- _ - _, 40 a Equatorial layer: % Height at center _____________________________________ 80 u _______ 60 u _______ 75 ,u. _______ 70 I.» _______ 70 u Height at periphery __________________ - ________________ 120 p ______ 110 y. ______ 100 u ______ ‘ 120 ,u ______ 140 ,u. Lateral chambers: Number ____________________________________________ 10 _________ 11 _________ 11 _________ 10 _________ 12 Length _____________________________________________ 40—100 ,u- _ _ 80—100 14- _ _ 80—100 a- _ - 80—100 a- _ _ 60440 p Height _____________________________________________ 20-40 ,u____ 30—40 u____ 30—40 14---- 30—40 11---- 20—40 M Thickness of floors and roofs __________________________ 10 u _______ 10 ,u _______ 5—8 a ______ 10 ,u _______ 10 ,u. Surface diameter of pillars ________________________________ None- _ _ ___i 100 u ______ 100 ,u ______ 60—100 11— _ _ 40 u 1 Locality 11a. 2 Locality 30. 3 Locality 43. SpeCImens from stations 11a, 30, and 43 are mter- Occurrence—Loos. 11a, 37, 39, 45, 55. Dlstrlbution mediate in character between L. pancanal’is and L. canellei. Therefore, as no reliable criterion was dis- covered by which this entire series could be broken at one definite point, these two species are combined. Occurrence—Loos. 11a, 30, 43, 53, 55. Distribution elsewhere: Upper Oligocene of Trinidad, Jamaica, Venezuela, near Tampico, Mexico, Antigua, and late Oligocene(?) part of Culebra formation, Canal Zone (Cushman, 1919a, p. 92, station 6019a, pl. 34, figs. 2, 3, identification questioned by Cushman; Woodring and Thompson, 1949, p. 238). Lepidocyclina (Lepidocyclina) montgomeriensis Cole . Plate 15, figures 11—13; plate 20, figure 7; plate 23, figure 4 1949. Lepidocyclina (Lep'tdocyclina) Montgomem'ehsis Cole, Jour. Palentology, vol. 23, pp. 270—272, pl. 53, figs. 2—11; pl. 54, fig. 8 (references and synonymy). Typical specimens of Lepidocyclina (L.) montgomer- tenets occur at two stations. Because this species has been illustrated by Panamanian specimens and dis- cussed recently, additional remarks will not be given. Occurrence—Lees. 108, 125. Distribution elsewhere: Upper Eocene of the United States and Trinidad. Lepidocyclina (Lepidocyclina) parvula Cushman Plate 15, figures 6—10 1919. Lepidocyclina parvula Cushman, Carnegie Inst. Washing— ton Publ. 291, p. 58, pl. 3, figs. 4—7. 1945. Lepidocyclina (Lepidocyclina) parvula Cushman. Cole, Florida Geol. Survey Bull. 28, pp. 30, 31, pl. 7, figs. 2—13; pl. 11, figs. 1, 2 (references and synonymy). Small specimens having thick-walled, lepidocycline sensu stricto embryonic chambers, hexagonal to short- spatulate equatorial chambers, strong pillars and thick floors and roofs for the lateral chambers are assigned to this well-known and well—described species. elsewhere: Upper Oligocene of Antigua, eastern Mexico, Jamaica, Florida, and Trinidad. Lepidocyclina (Lepidocyclina) waylandvaughani Cole , Plate 18, figures 1—10, 16, 17 1919. Lepidocyclz'na vaughani? Cushman (part), U. S. Nat. Mus. Bull. 103, p. 93, pl. 37, figs. 1, 2, 3 [not figs. 4, 5, nor pl. 38]. » Leptdocyclina miraflorensis? Vaughan, Nat. Acad. Sci. Proc., vol. 9, p. 257. Lepidocyclina (Lepidocyclina) miraflorensis? Vaughan. Vaughan, Geol. Soc. America Bull., vol. 35, p. 797. Lepidocyclina (Lepidocyclina) miraflorensis? Vaughan (part). Vaughan, ,1]. S. Nat. Mus. Proc., vol. 71, art. 8, p. 4, pl. 4, fig. 3 [not figs. 4, 5 which are L. (Nephrolepidina) vaugham' Cushman]. Lepidocycltna (Lepidocyclina) waylandvaughani Cole, Bull. Am. Paleontology, vol. 14, no. 53, pp. 21, 22, pl. 4, figs. 1—8, 10. Lepidocyclina (chidocycltna) waylandvaughani Cole. Vaughan, Smithsonian Misc. Coll., vol. 89, no. 10, pp. 13, 14, pl. 5, figs. 1—3, 5, 6. Cushman (1919a, pp. 93, 94) under the name L. vaughtmi figured specimens of two distinct species, one of which belongs to the subgenus Nephrolepidina and the other to the subgenus Lepidocyclina. Vaughan (1923, p. 257) recognized this fact, and proposed the name L. miraflorensis for these specimens that repre- sented Lepidocyclina. sensu stricto. Vaughan considered that Cushman’s (1919a) figure 5 on plate 37 demonstrates the features of the vertical section of L. mtraflorensts. This section shows that the lateral chambers are rectangular and have open cavities with very thin roofs and floors. Vaughan wrote: 1923. 1924. 1927. 1928. 1933. The margins of L. miraflorensis are somewhat swollen but are rounded, not so much thickened and abruptly truncate as in FAMILY ORBITOIDID AE L. vaugham’. There are no stout pillars in the vertical sections of L. miraflorensis, while there are such pillars in L. vaugham‘. The sample from locality 11a contained specimens that in equatorial section suggest L. miraflorensis, but in vertical section appear to be L. waylandvaughani Cole, a closely related species. Consequently, it is desirable to ascertain the characters by which several similar Oligocene species of Lepidocyclina s. s. can be distinguished one from the other. These species are L. mantell'i (Morton), L. supem (Conrad), L. forresti Vaughan, L. miraflorensis Vaughan, and L. wag/land- vaughani Cole. All of these species possess very similar features in equatorial section, but are described as differing in vertical section. The swollen edge of certain of the specimens desig— nated by Vaughan as L. miraflorensis suggests that the specimens that possess this feature may be L. vaugham’. Moreover, in preparing vertical sections of L. veugham‘ one observes that the lateral chambers beyond the center are shorter than those over the embryonic chambers, and that those areas outside the central zone are devoid of pillars. , A vertical section (pl. 18, fig. 14) was prepared from a specimen of L. vaugkani from locality 11a. At this locality L. mayhem: occurs with the Lepidocyclina which appears to be L. waylandvaughani. This vertical section which was not ground to the center has thin- walled, open, lateral chambers of the type assigned to L. miraflorensis. In the sample from locality 30 there are many well- preserved specimens of L. vaugham'. One of these (pl. 18, fig. 15) is so ground that it is a virtual dupli- cate of the section that Vaughan used as one of the cotypes of L. mimflorensis. The similarity in these off-center and oblique “ver- tical” sections, as well as oriented vertical sections, proves that Vaughan used specimens of L. vaugham} ' for the description of the vertical section of L. mim— florensis, just as Cushman included in L. vaughani specimens of the subgenus Lepidocyclina as well as the subgenus Nephrolepidina. Specimens belonging to the subgenus Lepidocyclina from locality 11a were compared with closely related species of the same subgenus illustrated on plate 18: L. waylandvaughani (figs. 1—10), L. forresti (fig. 11), L. supem (fig. 12), and L. mantelli (fig. 13). Comparison of views of enlarged vertical sections shows that L. mantelli (Morton) has long lateral cham- bers with very low chamber cavities. It is a distinct species. In L. supem (Conrad) the lateral chambers are shorter and the cavities more open than in L. mantellz'. ' represents a section of L. vaugham’. 21 But, the vertical section of L. forresti Vaughan has the same features as L. supera. Vaughan (1927, p. 2) distinguished L. forresti from L. supem by the fact that “L. supera has well-developed pillars and papillae.” This restudy of the type vertical section of L. forresti and topotypes of L. supera, demonstrates that this feature is not a valid criterion for discriminating these two species. Therefore, L. forresti Vaughan is a syn- onym of L. supem (Conrad). , The specimens from Panama under discussion have the same features in vertical section as do topotypes of L. waylandvaughani from Mexico. However, both the Mexican and the Panamanian specimens have lateral chambers with thickerxfloors and roofs and less regular alinement in tiers than does the only vertical section of L. miraflorensis Vaughan (1927, pl. 4, fig. 5). This vertical section was published by Vaughan several years after his original description of L. miraflorensis. The opinion has been expressed already in this dis- cussion that the off-center, oblique “vertical” section figured 'by Cushman (1919a, pl. 37, fig. 5) and used by Vaughan in the type description of L. miraflorensis The oriented vertical section (Vaughan, 1927) appears also to repre- sent L. wughaml for the following reasons: the lateral chambers are arranged in very regular tiers; the cavities of the lateral chambers are open, high, and rectangular; the roofs and floors of the equatorial chambers are thin; the equatorial layer expands rapidly toward the periphery of the test; and the central area of the test is dome-shaped. Oriented vertical sections of L. vaugham' have all of these features and may be observed in the specimens illustrated as figures 6—10 on plate 21. Therefore, it would appear that in the two available descriptions by Vaughan of L. miraflorensis vertical sections of L. vaugham' have been used. There is, however, in the sample from the U.S.G.S. locality 6255, half a mile south of Miraflores Station, Canal Zone, a Lepidocyclina s. s. known from the equatorial sections which Cushman and Vaughan have published. It is these equatorial sections to which the name L. mim- florensis should be applied. The oblique “horizontal” section (Cushman, 1919a, pl. 37, fig. 3) is designated the lectotype of this species. No vertical section of this species has been made. Although it is highly probable that L. mimflorensis and L. waylandvaugham' are conspecific, some doubt must exist until vertical sections of authentic L. miraflorensis are available. Therefore, the Panamanian specimens in this collection are assigned to L. way- landvaughani. Measurements and a brief description of the internal features of the specimens from locality 11a follow: 22 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE ,Measurements of vertical sections of Lepidocyclina (L.) waylandvaughani from locality 11a Specimen 1 1 2 3 4 Diameter ___________________________________________________ 3.6+ min-_-_ 4+ mm ______ 4.7+ mm-___ 4.6+ mm Thickness ___________________________________________________ 0.7 mm ______ 0.9 mm ______ 1.0 mm ______ 0.86 mm Embryonic chambers: Length ------------------------------------------------- 280 M. -------- 280 M -------- 180 M -------- 220 ,u Height -------------------------------------------------- 220 M ________ 160 M ________ 140 M ________ 220 M Thickness of outer wall ___________________________________ 30 M _________ 25 M _________ 30 M _________ '30 M Equatorial layer: Height at center ----------------------------------------- 80 M _________ 90 M --------- 80 M --------- 100 M Height at periphery ______________________________________ 140 M ________ 180 M ________ 200 M -------- 240 M Lateral chambers: Number ------------------------------------------------ 7 ____________ 8 ------------- 8 ------------ 7 Length _________ ~ ________________________________________ 80—140 M _____ 60—160 M _____ 80—160 M _____ 60—200 M Height -------------------------------------------------- 10—15 M. ------ 30—40 M ______ 20-35 M. ______ 20—40 M Thickness of floors and roofs _______________________________ 10 M _________ 20 M --------- 10—20 M ------ 20 M Surface diameter of pillars ____________________________________ 80 M _________ 100 M ________ 80 M _________ 60 M [Measurements of vertical sections of topotypes of Lepidocyclina (L.) waylandvaughani Specimen 1 2 3 4 Diameter ___________________________________________________ 6.5 mm ______ 6.6 mm ------ 4.2+ mm- __ - 4+ mm Thickness --------------------------------------------------- 0.76 min-‘- - _ _ 0.7 mm ______ 0.83 mm ----- 1.0 mm Embryonic chambers: Length _________________________________________________ 360 M ________ 380 M --------- 300 M ________ 300 M Height -------------------------------------------------- 250 M --------- 220 M --------- 250 M -------- 240 M Thickness of outer wall --------------------------------------- 40 M ---------- 20 M ---------- 40 M --------- 40 M Equatorial layer: Height at center ___________________________________________ 100 M --------- 85 M _________ 100 M ________ 80 M Height at periphery -------------------------------------- 260 M ________ 320 M -------- 220 M ________ 200 M Lateral chambers: Number ________________________________________________ 7 ____________ 7 ------------------------ 10 Length _________________________________________________ 40—180 M _____ 60—180 M _____ 80—180 M ----- 80—180 M Height -------------------------------------------------- 10—35 M ______ 20—25 M ______ 20 M _________ 20 M Thickness of floors and roofs ______________________________ 10 M _________ 10 M --------- 10 M _________ 10 M Surface diameter of pillars _____________________________________ 80 M _________ 40 M --------- 80 M _________ 60—200 M The embryonic chambers are bilocular, surrounded by a relatively thick wall whose width in equatorial sec- tions is about 40 M. The distance across both chambers is 340 M and the maximum width is 270 M in the available section. The dividing partition is thin and straight. Small periembryonic chambers with internal diameters of about 50 by 140 M occur opposite either end of the dividing partition. Several other periembryonic cham- bers border the bilocular chambers. The equatorial chambers are arcuate near the center of the test and have radial diameters of about 60 M and tangential diameters of about 60 M. The chambers near the periphery are short-spatulate, and have radial diameters of about 80 M‘and tangential diameters of about 80 M. ’ The lateral chambers are not in regular tiers. There is considerable overlapping of the lateral chambers from one tier to the adjacent one. Measurements of four vertical sections from topo— types of L. waylandvaughani are given for comparison with the specimens from Panama assigned to this species. Occurrence—Lees. 11a, 38. 'Upper Oligocene of Mexico, Antigua, and Trinidad. Distribution elsewhere: Lepidocyclina (Lepidoeyclina) yurnagunensis Cushman Plate 15, figure 3; plate 17, figures 5—18; plate 20, figures 11, 12 1919. Lepidocyclina canellei Lemoine and R. Douvillé, variety yumagunensis Cushman, Carnegie Inst. Washington Pub]. 291, p. 57, pl. 12, figs. 7, s. 1926. Lepidocyclina (Lepidocyclina) yurnagunensis Cushman. Vaughan, Geol. Soc. London, Quart. Jour., vol. 82, pp. 391—393, pl. 25, figs. 2—6 (references and synonymy). 1934. Lepidocyclt'na (Lepidocyclina) yurnagunensis Cushman. Cole, Jour, Paleontology, vol. 8, pp. 24, 25, pl. 3, figs. 4—6; pl. 4, figs. 8, 9. 1941. Lepz’docyclina (Lepidocyclina) yumagunensis Cushman. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p. 72, pl. 38, figs. 1—7. 1945. Lepidocyclina (Lepidocyclina) yurnagunensis Cushman. Cole, Florida Geol. Survey Bull. 28, p. 31, pl. 6, figs. 5, e. The widely distributed Lepidocyclina (L) 'yurvnagu- nensz's has been adequately described and illustrated. The specimens in, the present collection conform to the descriptions given from other localities. giving measurements of typical specimens follow. Two tables FAMILY ORBITOIDIDAE . 23 Measurements of equatorial sections of Lepidocyclina (L.) yurnagunensis from locality 45 / Specimen 1 l 2 3 4 Diameter _________________________________ 2.9 mm __________ 1 2.6 mm __________ 3.5 mm __________ 3.6 mm Embryonic chambers: ‘ ype _________________________________ Lepidocycline _____ . Nephrolepidine-__- Lepidocycline _____ Nephrolepidine Distance across both chambers __________ 260 u ____________ 240 n _____________ 80 n ____________ 420 u Maximum width _______________________ 220 u ____________ 240 M. ____________ 180 p ____________ 400 u 'Thickness of outer wall _________________ 20 p _____________ 20 [.4 _____________ 10 ,u _____________ 20 u Equatorial chambers: Radial diameter _______________________ 60 u _____________ 60 ,u _____________ 60 p. _____________ 80 u Tangential diameter ____________________ 40 a _____________ l 40 a ______________ 40 a _____________ 1 60 a Measurements of vertical sections of Lepidocyclina (L.) yurnagunensis from locality 45 Specimen 1 2 3 4 5 Diameter ____________________________________________ 2.4 mm____ 2.0 mm____ 2.5 mm____ 2.8 mm____ 2.9 mm Thicknessnnw. ______________________________________ 0.8 mm---_ 0.78 mm____ 0.92 mm____ 0.9 mm____ 1.0 mm Embryonic chambers: Length ___________________________________________ 330 M ______ 190 ,u ______ 210 ,u. ______ 290 ,u. ______ 230 [.1 Height ___________________________________________ 170 u ______ 120 It ______ 140 It ______ 180 It ______ 120 in Thickness of outer wall ______________________________ 25 n _______ 15 ,u. _______ 15 u _______ 20 u _______ 15 u Equatorial layer: Height near center _________________________________ 80 ,u _______ 60 p _______ 80 p. _______ 80 n _______ 80 p. Height at periphery ________________________________ 160 n ______ 90 u _______ 120 ,1 ______ 140 u ______ 130 [4 Lateral chambers: Number __________________________________________ 8 _____ . _____ 8 __________ 6 __________ 10 _________ 9 Length ___________________________________________ 100-140 M“. 120 ,u. ______ 80—300 p____ 100—240 It--- 1804220 y. Height ___________________________________________ 20-40 n____ 20-30 p____ 30—80 M--.” 20-40 in-“ 20 u Thickness of roofs and floors ________________________ 15 u _______ 10 a _______ 15 u _______ 15 n _______ 20 p. Surface diameter of pillars ______________________________ 80 ,a _______ 60 p. ....... 100 p- - ,,__ 60 ,u. _______ 50 n Occurrence—Loos. 39, 45, 54. Distribution else- where: Upper Oligocene of Cuba; Cayman Brac, Cay- man Islands; Haiti; _Antigua formation of Antigua; Moneague formation of Jamaica; Suwannee limestone of Florida; Trinidad. Lepidocyclina (Lepidocyclina) yurnagunensis morganopsis Vaughan Plate 15, figures 1, 2, 4, 5; plate 23, figures 5—7, 9 1933. Lepidocyclina yurnagunensis, var. 77zorganopsis Vaughan, Jour. \Vashington Acad. Sci, vol. 23, p. 354. 1945. Lepidocyclina (Lepidocyclina) yurnagunensis, var. mor- ganopsis Vaughan. Cole, Florida Geol. Survey Bull. tribution elsewhere: Upper Oligocene of Cuba, Florida, and Trinidad. Subgenus NEPHROLEPIDINA H. Douvillé, 1911 Lepidocyclina (Nephrolepidina) chaperi Lemoine and R. Douvillé Plate 8, figures 5—8; plate 9, figures 3—19; plate 10, figures 1—10; plate 11, figures 1—8; plate 12, figures 1—15; plate 20, figures 8~10; plate 23, figures 8, 11, 12. . 1904. Lepidocyclina chaperi Lemoine and R. Douvillé, Soc. Géol. France Mém., vol. 12, pp. 14, 15, pl. 2, fig. 5. 1919. Lepidocyclina subraulinii Cushman, Carnegie Inst. Wash- ington Pub. 291, pp. 62, 63, pl. 11, figs. 6, 7 [probably not pl. 12, figs. 5, 6]. 28, pp. 31, 32, pl. 6, figs. 1—4, 7,, 8 (references). 1919. Lepidocyclina perundosa Cushman, idem, p. 63, pl. 11, M al 8 heric individuals of Le idoc Olin L. fig- 8- Lg 0 P . . tlf) y 1:1, ( )f 1920. Lepidocyclina fragilis Cushman, U. S. Geol. Survey Prof. yurnaguuensts morganopsis pOSSGSS 0 same ype 0 Paper 125, pp. 63, 64, pl. 22, figs. 1, 2 embryonlc and equatorlal chambers as does L. (13-) 1928. Lepidocyclina (Nephrolepidina) haddingtonensis Vaughan, yurnagunenSis. The varlety, however, has very heavy Jour. Paleontology, vol. 1, pp. 292—294, pl. 50, figs. 1, 2. pillars Whicll appear in vertical sections! and large 1933. Lepidocyclina (Nephrol-epidma) SGTnMCSi Vaughan and papillae which show in external VieWS. Cole. Vaughan, Smlthsonlan Misc. Coll., vol. 89, no. . . . . 10, pp. 29, 30, pl. 15, figs. 3—5; pl. 30, fig. 1; pl. 31, figs. The microspheric spoolmens are relatively large and, 1 la‘ pl 32 figs 2 3 .\ o I u n 7 ’ ‘ I ' ’ ‘ therefore, In a. sample 0f Indurated rogk that 15 belng 1933. Lepidocyclina (Nephrolepidina) semmesi var. granosa broken for spe01mens for oriented sections, the micro- Vaughan and Cole, idem, p. 30, pl. 30, fig. 2. Spheric forms are more easily obtained than the Smaller, 1933. Lepidocyclina (Nephrolepidina) tantoyucensis Vaughan more fragile megalospheric specimens. This may ”id 0013’ Idem! pp“ 30’ .3?! pl‘ 15’ figs: 1' 2' account for the apparent abundance of microspheric 1937. Lepidocyclma.(Nephrolepidma) fragilis Cushman, var. . . . . . cubenSis ’lhladens, Jour. Paleontology, vol. 11, p. 104, 1nd1v1duals which were obtalned from the present , 11 . pl. 17, fig. 6, pl. 18, fig. 7. CO ectlon. 1937. Lepidocyclina (Lepidocyclina) tschoppi Thiadens, idem, Occurrence.—Microspheric specimens, locs. 11a, 37, 38, 39, 45, 53; megalospheric specimens, 100. 53. Dis— pp. 103, 104, pl. 17, figs. 1, 3; pl. 18, fig. 6; pl. 19,,fig. 1; text fig. 3H. 24 1941. Lepidocyclina (Nephrolepidina) sanfernandensis Vaughan ' and Cole, Geol. Soc. America Spec. Paper 30, pp. 73, 74, pl. 42, figs. 1—6; pl. 43, figs. 1—3; pl. 44, fig. 1. 1945. Lepidocyelina (Nephrolepidina) sanfemandensis Vaughan and Cole, var. tallahasseensis Cole, Florida Geol. Survey Bull. 28, pp. 34—39, pl. 1, figs, 16, 17; pl. 2, figs. 5—7; pl. 3, figs. 1—6. Lemoine and R. Douvillé (1904, pp. 14, 15) described Lepidocyclina chaperi as a new species from Haut-Chagres, Panama. The original description is so brief that it is impossible to recognize the species from the details given. The species is illustrated by one external view. - Fortunately, H. Douvillé (1924, pp. 44, 45) later gave a fuller description of this species and illustrated it by two detailed photomicrographs of the surface of the species and several drawings of the embryonic apparatus, equatorial chambers, and the distribution of the pillars. Woodring supplied topotypes collected by E. R. Lloyd in 1918. Although these specimens are partly silicified, satisfactory equatorial and vertical thin sections were made. Therefore, it is possible to assign certain specimens from locality 23 to Lepidocyclina chaperi with absolute certainty. These specimens possess every feature mentioned or illustrated by Douvillé and are identical EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE with the topotypes. A description of the specimens from locality 23, follows: Mcgalospheric generation—Test of moderate size, having diameters from 6 to 11 mm; disc-shaped, with a thin outer edge. The central area is slightly inflated, and the test slopes more or less regularly from this area to the periphery. Most of the specimens are very slightly selliform, but a few are strongly so. The central area has small, indistinct low papillae evenly scattered over it. The peripheral zone of the test is Without papillae and usually the outlines of the equa- torial chambers can be seen in this peripheral area. The embryonic chambers are nephrolepidine, large, and have outer walls that may be either thin or thick. Several elongate periembryonic chambers occur with the two larger ones opposite the ends of the dividing partition between the embryonic chambers. Some specimens have initial and second embryonic chambers of almost the same size (pl. 11, fig. 5). In this type the second chamber barely embraces the initial chamber. Specimens with this type of embryonic apparatus do not difl’er in any other respect from those with the strongly embracing second chamber. The equatorial chambers have several shapes; some are short-hexagonal, others are arcuate, and a few are Measurements of equatorial sections of Lepidocyclina (N .) chaperi from locality 23 Specimen 2 3 4 Diameter _______________ , ......................... 8.3 1nm,- - _. ,.___._.. 11.0 mm _________ 12.0 mm _________ 8.0 mm Embryonic chambers: Diameters of initial chamber __________________ 520x860 a ,,,,,,, 520x820 u _______ 480‘X 750 p _______ 500x 760 u Diameters of second chamber __________________ 300>< 1040 u ,,,,,,, 460x 1160 p. ______ 520X 1180 y ______ 300>< 830 u Distance across both chambers ________________ 840 u ____________ 1010 ,u ........... 1010 M ___________ 820 ,u. Thickness of outer wall _______________________ 80 u _____________ 30 u _____________ 30 ,u _____________ 60 u Equatorial chambers: Near center: Radial diameter: _ _ - _ _ , _ _ 1 _ .‘ _____________ 60—100 a _________ 140 u ____________ 120 p ____________ 100 u Tangential diameter ______________________ 100—140 pt ________ 140 ,u ____________ 100—160 a ________ 100 in Near periphery: Radial diameter _________________________ 40—60 p. __________ 80 p _____________ 60—80 ,u __________ 70 ,u Tangential diameter ______________________ 80—100 In _________ 80—90 ,u __________ 100—120 M ________ 90 p. Measurements of vertical sections of Lepidocyclina (N.) chaperi from locality 93 Specimen 1 2 3 4 5 6 Diameter ________________________________ 6.7 mm____ 8.1 mm____ 8.4 mm__-- 9.2 mm____ 10.8 mm_-_- 9.8+ mm Thickness ________________________________ 1.62 mm____ 1.72 mm_-_- 1.54 mm-___ 1.44 mm__-_ 1.5 mm__ _ - 1.6 mm Embryonic chambers: / Length ______________________________ 840 a ______ 700 u ______ 750 p ______ 840 u ______ 860 ,u ______ 780 11 Height _______________________________ 640 ,u ______ 460 u ______ 560 c ______ 600 pt ______ 540 a ______ 340 in Thickness of outer wall ________________ 60 a _______ 60 ,u _______ 60 u _______ 40 [1 _______ 60 ,u _______ 60 p. Equatorial layer: Height at center ______________________ 140 c ______ 140 u ______ 150 p ______ 150 u ______ 180 u ______ 140 in Height at periphery ___________________ 200 ,a ______ 260 p- - - -1- 220 ,u ______ 300 ,u ______ 300 p ______ 340 u Lateral chambers: Number on each side of embryonic 8 __________ 12 _________ 12 _________ 10 _________ 12 _________ 11 chamber. - Length ______________________________ 80—140 u- _ _ 100—160 ,u_- 110—220 ,u._ - 100—220 a. _ 120—160 M— - 120—240u Height _______________________________ 20 u _______ 20 u _______ 10—20 ,u- _ _ _ 20 p. _______ 10 p. _______ 10—15 M. Thickness of roofs and floors ____________ 20—40 [.t- _ _ - 15—30 M_ _ __ 10—20 #— - - - 10 u. _______ 20 u _______ 20—30 p. Surface diameter of pillars __________________ 60—80 u__ _ _ 100—160 [.t- _ 80—140 [4. _ _ 100 p. ______ 100 u ______ 100—120 u FAMILY ORBITOIDIDAE Measurements of equatorial sections of topotypes of Lepidocyclina (N.) fragilis Cushman 25, Specimen 1 2 3 4 Diameter _____________________________________ 4.7 mm ___________ 4.6 mm ___________ 7 4 mm ___________ 8.5 min Embryonic chambers: Diameters of initial chamber ________________ 620x880 ,u _______ 840x 1140 u ________________________ 530x 780 ,u. Diameters of second chamber ________________ 480x 940 u _______ 540x 1280 p. ________________________ 440x960 [1. Distance across both chambers ______________ 1120 n ___________ 1420 p. ___________ 1180 p: ___________ 990 ,1 Thickness of outer wall _____________________ 60 u _____________ 40 a _____________ 60 u _____________ 40 p Equatorial chambers: Near center: - Radial diameter ________________________ 140 u ____________ 120 u ____________ 140 u ____________ 140 p Tangential diameter ____________________ 120 u _______ ' _____ 110 p ____________ 140 p ____________ 130 u Near periphery: , Radial diameter _______________________ 120 ,4 ____________ 140 p. ____________ 100 ,u ____________ 120 p. Tangential diameter ____________________ 120 u ____________ 90 p _____________ « 100 H ____________ 140 It Measurements of vertical sections of topotypes of Lepidocyclina (N.) fragilis Cushman Specimen 1 2 3 4 Diameter _____________________________________ 5.8 mm __________ 6.5+ mm ________ 7.8+ mm ________ 8.1+ mm Thickness _____________________________________ 1.42 mm- - _ _ l l - - - 0.96 mm _________ 1.44 mm _________ 1.42 mm Embryonic chambers: Length ____________________________________ 1060 u _________ ,- Height ____________________________________ - Thickness of outer wall _____________________ 45 u _____________ Equatorial layer: Height at center ___________________________ 160 u ____________ Height at periphery ________________________ 160 [t ____________ Lateral chambers: Number __________________________________ 9 ________________ Length ___________________________________ 140-240 a ________ Height ____________________________________ 20 u _____________ Thickness of floors and roofs ________________ 20—30 M __________ Surface diameter of pillars ______________________ 100 u ____________ rhombic. The largest equatorial chambers occur near the center of the testand they become progressively smaller toward the periphery. The lateral chambers may be arranged in rather regular tiers (pl. 9, fig. 9) or they may overlap from one tier into the adjacent one (pl. 9, fig. 11). The chamber cavities are long, low. In some specimens the chamber cavities are more appressed than in others. In the specimens with the most appressed chamber cavities the roof and floors of the chambers are very thick. In both types the floors and roofs of the lateral chambers are thicker in the chambers adjacent to the equatorial plane and thinner in the chambers near the surface. Moreover, there is complete gradation between the types with thin roofs and floors and those with thick ones. Small wedge-shaped pillars are irregularly distributed in the central area. The details of L. chaperi suggest features similar to those noted previously in the preparation of a suite of thin sections of topotypes of L. fragilis Cushman. As the sections of the Panamanian specimens as- signed to L. chaperi and those of topotypes of L. fragilis are studied, it becomes more and more apparent that it is impossible to distinguish the two species, and, therefore L. fragilis is a synonym of L. chaperi. Topotypes of L. sanfernandensis tallahasseensis Cole from a well in Florida were available for study. These ’ specimens were separated into two lots, one containing inflated specimens, the other lenticular specimens. The inflated type is illustrated by a vertical section (pl. 9, fig. 19) and two equatorial sections (pl. 11, figs. 1, 2). The lenticular type is illustrated by a vertical section (pl. 9, fig. 18) and a horizontal section (pl. 11, fig. 3). These illustrations prove that there are no essential differences between certain specimens named L.,fragilis and others called L. sanfernandensis tal- lahasseensis (compare fig. 17 with 18, pl. 9, and fig. 3, pl. 11 with figs. 1, 2, pl. 10). Because there is complete gradation between speci- mens of the lenticular and the inflated type named L. sanfernandensis tallahasseensis, all of these must be assigned to L. fragilis and therefore, to L. chaperi. It is, moreover, clear that the specimens from Trinidad named L. sanfernandensis Vaughan and Cole fall within this series. Other specimens in the Panamanian collection had been identified as L. (Nephrolepidina) semmesi Vaughan and Cole, a species from the Mexican upper Eocene. 26 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE These specimens occur principally at localities 125 and 140. A brief description of the specimens from locality 125 follows: The normal embryonic chambers are nephrolepidine, but there is considerable variation in both shape and size. In some specimens the embryonic chambers are nearly lepidocycline-sensu stricto, whereas others have gigantic nephrolepidine embryonic chambers. Illeasurements of equatorial sections of Lepidocyclina (N.) chaperi from locality 125 Specimen 1 2 3 4 5 6 7 8 Diameter ____________________________ 3.8 mm ________ 4.5 mm ________ 4.2 mm ________ 5.2 mm ________ 6.0 mm ________ 6.8 mm ________ 7.4 mm ________ 8.0 mm Embryonic chambers: Diameters at initial chamber _________ ‘4‘70X680 p _____ 600x870 :4 _____ 470x680 11. . ... 880x1020 p. _ __ 330x480 [l ..... 340x570 y ..... 300x 480 n Diameters of second chamber ________ 310x720 11— _ .-, 420x1050 a. _ __ . 450x760 u _____ 440x1480 u- i _ _ 3100me u _____ 280><660 p _____ 320 X620 u Distance across both chambers. _ 810 M _____ 1040 p _________ 940 p ..... _ 1340 u _________ 640 u. _ N. ‘ 640,1 Thickness of outer wall .............. '40 u ___________ 20 p ___________ 35 a ___________ 35 [.t ___________ 50 It ........... 40 u Equatorial chambers: Near center: Radial diameter _________________ 120 ,4 __________ 120 u .......... 110 a __________ 110 n .......... 90 u ........... 100 p. Tangential diameter ............. 120 u __________ 120 ,1 __________ 130 u __________ 110 u .......... 80 u ___________ 110 ,1: Near periphery: , Radial diameter _____ 100 u __________ 100 u Tangential diameter _____________ 110 ........... 140 n .......... 140 u The equatorial chambers are commonly short-spatulate, but some are hexagonal and others are arcuate. All three types may occur in the same equatorial section. Measurements of vertical sections of Lepidocyclina (N.) chaperi from locality 125 Specimen 1 2 3 4 5 (i 7 8 9 Diameter _________________________________ 2.6 mm ______ 4.2+ mm.._- 4.4 min ______ 6.3+ mm.._- 5.3 mm ...... 6+ mm _____ 8+ mm _____ 6.6 mm ______ 7.1+ mm Thickness _________________________________ 0.78 mm _____ 1.06 mm _____ 1.22 _________ 1.5 mm ______ 1.24 mm _____ 1.6 mm ...... 1.7 mm ______ 1.8 mm ______ 2.2 mm Embryonic chambers: . Length ________________________________ 640 H ________ 700 u Height ................... 460 ,4 Thickness of outer wall ________________ 60 p. Equatorial layer: Thickness at center ___________________ 150 1‘ Thickness at periphery ________________ 210 ,1. Lateral chambers: Number ______________________________ 18 Length"; ..... _ _ _ 120—140 A. . __ 160—240 is. . -- 100-300 [1 Height ................................ 10 p ......... 10 p. _________ 10—20 M ______ 20 u _________ 20 u _________ 20 u Thickness of roofs and floors ........... 30-40 a ______ 20—40 a ...... 20-30 M ______ 20 [.4 ......... 20 u _________ 20 u Surface diameter of pillars _________________ 80—100 u _____ 60—140 u _____ 100—160 u. . . _ 80—140 ,4 ..... 120—200 [4. _ ._ 120 u ........ 80—100 A ..... 60-260 1.: _____ 160—200 M The lateral chambers are not arranged in regular tiers. There is overlapping from one tier to the adjacent one. The cavities of the lateral chambers adjacent to the equatorial layer are low and slitlike between very thick roofs and floors, but those near the periphery are more open and their floors and roofs have a thickness about equal to the height of the cavities. The thinner speci— mens do not possess this outer zone of open lateral chambers. Although these specimens at first glance appear to be different from those assigned to L. chapcri, detailed study shows that there are no valid characters upon which a separation can be based. Vaughan and Cole (1933, p. 31) wrote: Lepidocyclina semmesi and L. tantoyucensis both belong to the subgenus N ephrolepidina and are so closely related to L. (N ephro- lepidina) fragilis Cushman that the senior author has vacillated between referring them to that species and assigning new names to them. ' If Vaughan and Cole had had available the present collections, they would have assigned the Mexican forms to L. fragilis Without question. Associated with the larger specimens already de- scribed are certain small, strongly umbonate specimens. A description follows: Small specimens with a strong umbo and a narrow rim occur infrequently in the sample from locality 125. Measurements of an equatorial and a vertical section follow: Diameter, 2.26 mm; thickness through center, 1.0 mm ; diameter of umbo, 1.2 mm; width of rim, 0.5 mm; thickness of rim, 0.24 mm. The distance across both embryonic chambers is 780 ,u and the height of the embryonic chambers is 640 u. The equatorial chambers are short-spatulate. Those near the periphery have radial diameters of 130 u and tangential diameters of 80 ,u. FAMILY ORBITOID IDAE There are two or three layers of lateral chambers over the embryonic chambers. The cavities of these chambers are low and slitlikc between thick floors and roofs. These specimens were identified as Lepidocyclina (Lepidocyclina) tschoppi Thiadens (1937, pp. 103, 104) but study demonstrated that they represent immature specimens of L. (Nephrolepidina) chaperi. The large thick-walled embryonic apparatus, the short-spatulate equatorial chambers, and the low, slitlikc cavities of the lateral chambers are features which characterize L. (Nephrolepidina) chapem‘. The Cuban specimens were not referred to the correct subgenus. The embryonic apparatus of L. (Nephro- lepidina) chaperi varies from nearly lepidocycline sensu stricto t0 nephrolepidine. L. tschoppi occurs in Cuba in beds which Thiadens referred to “transitional beds between the upper Eocene and Oligocene.” These same beds contain L. (Nephrolepidina) fragilis cubensis Thiadens. This new variety of L. fragilis represents one of the adult stages of L. (Nephrolepidina) chapem'. Microsphem’c generation—A vertical section of a microspheric individual with a diameter of 12 mm and a thickness through the center of 2.8 mm has an umbonate portion with a diameter of 5 mm surrounded by a rim 4 mm wide. The equatorial layer has a height at the center of the test of 120 ,u and at the periphery 300 ,u; these measure— ments include the thickness of the roofs and floors. There are 22 lateral chambers to a tier on each side of the equatorial layer at the center of the test. The lateral chambers are arranged in tiers, but there is overlapping from one tier to the adjacent one. The cavities of the lateral chambers are low and slitlikc between thick roofs and floors in a zone adjacent to the equatorial layer. In the peripheral zone the cavities of the lateral chambers become more open and the roofs and floors are thinner. The cavities of the lateral chambers in this outer zone have a height of 30 to 40 ,u and a length of 160 to 360 ,u.. The thickness of the roofs and floors of these chambers is from 20 to 40 p. The inflated portion of the test has long, slender pillars. Average pillars have a surface diameter of 200 M. . A specimen with a thickness through the center of 3.8 mm has 25 lateral chambers to a tier on each side of the equatorial layer. The other details of this specimen are similar to the details of the other available thin section. These microspheric specimens from locality 125 agree in every detail with L. (Lepidocyclina) submulim'i Cushman as illustrated by Vaughan (1933, pl. 2, figs. 1—3). The vertical section (Vaughan, 1933, pl. 3, 27 fig. 1) of a megalospheric specimen assigned by Vaughan probably to L. subraulinii shows many of the features of the inflated type of specimen from Florida called L. sanfemandensis tallahasseensis. Occurrence.~Locs. 15, 23, 125, 137, 138a, 140, 150. Distribution elsewhere: Upper Eocene of Florida (as L. fragilis and L. sanfernandensis tallahasseensis), Cuba (as L. peru'ndosa and L. submulinii), Mexico (as L. semmesi and L. tantoyucensis), Trinidad (as L. san- fernandensis) and Jamaica (as L. haddingtonensis). Remarks.—From beds assigned to the uppermost Eocene 2 in America seven species and three varieties of Nephrolepidina have been described: Lepidocyclina (Nephrolepidina) chaperi Lemoine and R. Douvillé (1904) Panama; perimdosa Cushman (1919) Cuba; fragilis Cushman (1920) Florida; fragilis cubensis Thiadens (1937) Cuba; haddingtonensis Vaughan (1928) Jamaica; semmesi Vaughan and Cole (1933) Mexico; semmesi granosa Vaughan and Cole (1933) Mexico; tantoyucensis Vaughan and Cole (1933) Mexico; sanfemandensis Vaughan and Cole (1941) Trinidad; sanfernandensis tallahasseensis Cole (1943) Florida. To this list should be added probably L. persimilis H. Douvillé (1924) from beds reported by him to be Oligocene in age at Erin Point, Trinidad. This species is inadequately described and is illustrated only by drawings of the embryonic and equatorial chambers and distribution of pillars. These features suggest that L. persimilis is in reality L. chaperi, but a positive statement should not be made until topotypes can be examined. All of these species possess large nephrolepidine embryonic chambers, short-spatulate to arcuate equa- torial chambers, low cavities in the lateral chambers with floors and roofs about equal in thickness to the height of the cavities, and usually small pillars. The characters of individuals from one locality vary, and the predominant types of individuals vary from locality to locality, but the essential characters are similar in all of these specimens. Thus, the author believes them to be of only one species. Lepidocyclina (Nephrolepidina) dartoni Vaughan Plate 19, figures 1—8 1933. Lepidocyclina (Nephrolepidina) dartom' Vaughan, Smith— sonian Misc. 0011., vol. 89, no. 10, pp. 36, 37, pl. 25, figs. l, 2; pl. 26, figs. 1—3. Test with a central, evenly inflated umbonate area which is surrounded by an undulating rim. Several rays on the rim give the test a stellate margin. These rays are faint in some specimens and strong in others. The rays do not extend into the umbonal area in either 2 Recently, MaeNeil (1944, pp. 1324—1328) placed the L. fragilis zone in Florida in the lower Oligocene. New evidence from Florida (Wayne Moore, personal com- munication) indicates that this assignment is incorrect. Moore places the L. fragilis zone in the uppermost Eocene because of the presence of Helicolepidinc spiralis Tobler. 28 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE type. Slightly weathered specimens have relatively Measurements of equatorial scallionlstoflliepidocyclina (N.) dartoni / . ram 000 ’L a large polygonal pits on the surface of the umbo. These y pits are a reflection of the large, open lateral chambers. spec‘men A specimen with a diameter of more than 4.3 mm has 1 2 an umbo with a diameter of about 2.6 mm. A strong ray projects 0.6 mm beyond the periphery of the test. Diameter _____________________ 4.44 mm____ 3.54 mm The measurable diameter of the lar est s ecimen is 4 8 Embryonic Chambew , . g P ‘_ Diameters of initial chamber- 160x 240 u- _ _ 140>< 180 ,4 mm, but a part of the rim has been destroyed. Thls Dismeters of second cham- 180x350 n--- 100x260 n e n 1 er. specimen has an umbo With a diameter of. 2:8 mm. Distance across both cham— 360 I, ________ 260 I, The embryonic chambers are nephrolepldine. There bers. are four principal periembryonic chambers, one. of them Equitglitngfiigtgl‘slfr wall """ 25 " """"" 25 ” lying at each end of the curved diViding partition be- Near Rcegteiréi 60 60 - a is. iameter _______ u _________ p tween the embryonic chambers. The other two are Tangential diameter--__ 60 M _________ 40 u Situated so that one is on each Slde of the larger, reniform Near Rpegiplhgry: t 60—120 60410 - a la lame er _______ M _____ M embryomc Chamber- , , Tangential diameter__-_ 60 n _________ 50—60 M Measurements of equatorial sections follow: Measurements of vertical sections of Lepidocyclina (N.) dartoni from locality 11a Specimens 1 2 3 Total diameter _______________________________________________ 4.0+ mm ___________ 2.5+ 1nm_____- _ _ _ - - 3.4+ mm Diameter of umbo ____________________________________________ 2.2 mm _____________ 1.3 mm _____________ 2.6 mm Width of rim _________________________________________________ 0.6 mm _________________________________ 0.5+ mm Thickness ___________________________________________________ 1.52 mm ____________ 1 0 mm _____________ 1.2 mm Embryonic chambers: Length __________________________________________________ 260 u ______________ 250 u ______________ 360 p. Height __________________________________________________ 160 u ______________ 180 p ______________ 220 ,u Thickness of outer wall ____________________________________ 20 p. _______________ 20 u _______________ 30 n Equatorial layer: .. Height at center __________________________________________ 80 p _______________ 80 u _______________ 60 u Height at periphery _______________________________________ 120 u ______________ 140 p ______________ 110 n Lateral chambers: Number _________________________________________________ 10 _________________ 9 __________________ Length __________________________________________________ 240 u ______________ 180—220 [.1 __________ 120-300 1.: Height __________________________________________________ 40 n _______________ 40 n _______________ 40 n Thickness of floors and roofs _______________________________ 20 u _______________ 20 ,u- _ _; ___________ 20 u Surface diameter of pillars _____________________________________ l 100}; __________________________________ 95 ,u. The equatorial chambers are rhombic near the center of the test, but toward the periphery they become spatulate t0 elongate-hexagonal, with radial diameters greater than the tangential. The radiate character of the test is expressed by the arrangement of the equa- torial chambers. The lateral chambers are arranged in regular tiers. They have large, open rectangular cavities between rather strong roofs and floors. Slender pillars may or may not be present in the umbonal area. Occurrence—Loo. 11a. Distribution elsewhere: Only at type locality in Cuba in Oligocene beds. Remarks.—The thin sections on which the type description of this species is based are random ones cut from the matrix material in which the specimens were found. Although the specimens from Panama are smaller and have considerably smaller embryonic chambers than the type specimens, the other similar- ities of the internal features of the Cuban and Pan- amanian specimens are proof that the specimens in the present collection should be referred to the Cuban species. Lepidocyclina (Nephrolepidina) tournoueri Lemoine and R. Douvillé Plate 19, figures 9—12 Lepidocyclina tournoueri Lemoine and R. Douvillé, Soc. Géol. France Mém. 32, p. 19, pl. 1, fig. 5; pl. 2, figs. 2, 14; pl. 3, fig. 1. Lepidocyclina tournoueri Lemoine and R. Douvillé. H. Douvillé, Soc. Géol. France Mém., n. s., vol. 2, no. 2, p. 78, pl. 6, figs. 8—12, text figs. 62-68. Leptdocyclina tournoueri Lemoine and R. Douvillé. Vaughan, Geol. Soc. America Bu11., vol. 35, p. 798, pl. 33, figs. 6, 7. Lepidocyclina (Nephrolepidina) tournoueri Lemoine and R. Douvillé. Vaughan, Smithsonian Misc. Coll., vol. 89, no. 10, pp. 25, 26, pl. 13, figs. 1, 2. Lepidocyclina (Nephrolepidina) tempanii Vaughan and Cole. Vaughan, idem, pp. 26, 27, pl. 13, figs. 3—6. Lepidocyclina (Nephrolepidina) tempam'i Vaughan and Cole. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p. 75, pl. 39, figs. 5—9. Lepidocyclina (Nephrolepz'dina) tournoueri Lemoine and R. Douvillé. Cole, Florida Geol. Survey Bull. 28, p. 34, pl. 5, figs. 18, 19. 1904. 1924. 1924. 1933. 1933. 1941. 1945. The two species, Lepidocycltna tournoueri and L. tempanli, are distinguished by the fact that L. tempan'li FAMILY 0R has much more elongate equatorial chambers than L. tournouem'. The maximum radial diameter of periph- eral equatorial chambers of L. tournoneri is given by Vaughan (1933, p. .26) as 67 ,u whereas equatorial chambers of L. tempam't have a maximum radial diameter. of about 110 p. The writer prepared several additional equatorial sections of 'L. tournouer'i from Arbol Grande, near Tampico, Tamaulipas, Mexico, for comparison. These sections have peripheral equatorial chambers which have radial diameters from 65 to 120 a. It would appear from this that it is impossible to distinguish between these two species. L. (Nephrolepidina) lehner'i van de Geyn and van der Vlerk (1935, p. 251, figs. 14, 15), an inadequately described and illustrated species from the Oligocene, is probably a' synonym of L. tournoueri. Measurements of equatorial sections of BITOIDIDAE 29 Occurrence—L00. 45. Distribution elsewhere: Re-_ ported from Antigua and Trinidad as L. tempanii, and from near Tampico, Tamaulipas, Mexico. Lepidocyclina‘(Nephrolepidina) vaughani Cushman Plate 18, figures 14, ‘15,; plate 20, figures 1—6; plate 21, figures 1—15 1919. Lepidocyclina vaugham} Cushman, U. S. Nat. Mus. Bull. 103, p. 93, pl. 37, figs. 4, 5 [not figs. 1, 2, 3]; pl. 38. 1933. Lepidocyclina (Nephrolepidina) vaughani Cushman. Vaughan, Smithsonian Misc. 0011., vol. 89, no. 10, pp. 32, 33, pl. 16, figs. 1—5 (references). Externally this species is characterized by a small umbo bordered by a wide rim, the outer edge of which is thickened so that a raised flange borders the outer periphery of the test. Vaughan has discussed this. species rather fully. Measurements of equatorial and vertical sections which demonstrate the variation among individuals follow. Lepidocyclina (Nephrolepidina) vaughani Locality 30 38 43 l Specimen 1 2 3 4 i 5 : Diameter ___________________________________ 8.6 mm _____ ’.- 7+ mm ______ Broken _______ Broken ______ 5.7+ mm Embryonic chambers :' Diameters of initial chamber ______________ 260 X 340 u- _ _ 290x 340 p- _ _ 420x 460 a- _ - 440x 550 u- _ _ 590>< 900 ,u Diameters of second chamber _____________ 160 X 620 a- _ - 340x 660 u- _ _ 360x 720 a- - _ 300x 860 a- _ _ 395 X 1340 ,u — Distance across both chambers ____________ 460 n ________ 650 p. ________ 800 a ________ 760 ,u ________ 1000 u Thickness of outer wall ___________________ 20-30 a _ _ _ _ _ _ 20 u _________ 20 u _________ 20 a _________ 20 ,u. Equatorial chambers: '~ Near center: Radial diameter _____________________ 60 u _________ 120 M ________ 120 ,u ________ 1 10 p ________ 100—160 ,u Tangential diameter _________________ 60 u _________ 80 a _________ 90 p. _________ 100 p. ________ 90—100 ,u Near periphery: Radial diameter _____________________ 60—80 a ______ 100—150 a _ _ _ _ Broken _______ Broken _______ 120 ,u Tangential diameter _________________ 60-80 ,1 ______ 100 [1. _____________ do ____________ do _______ 80 n Measurements of vertical sections of Lepidocyclina (Nephrolepidina) vaughani Locality 11a 30 38 43 123 Specimen 1 2 3 4 5 6 7 8 Diameter .............................................. 9.4 mm ______ 8.0 mm ______ 7.2+ mm _ Broken ...... Broken ______ Broken ...... Broken ______ 7.9+ mm Thickness _____________________________________________ 1.54 mm _____ 1.7 mm ______ 1 44 mm _____ 1.4 mm ______ 1.2 mm,_._.. 1.7 mm ______ 1.42 mm _____ 1.3 mm Diameter of umbonal area ...................... _-_ 3.0 mm ...... 3.0 mm ______ 2 4 mm ______ 2.4 mm ______ 2.6 mm ...... 3.4 mm ______ 3.4 mm _____ , 2.0 mm Thickness of flange at its center ................. ___ 0.44 mm ..... 0.56 mm ..... 0 4 mm ______ Broken ______ Broken ______ 0.56 mm _____ Broken ______ 0.4 mm Thickness of expanded edge of flange ................... 0.66 mm ..... 0.7 mm ...... 0 44+ mm... _____ do ____________ do _______ Broken ........... do _______ 0.52 mm Embryonic chambers: Length ............................................ 500p ________ 540u_.____._ 360;: ________ 1100M _______ 780p ........ 960M ........ 600}: ........ 600}: Height ...................................... 240 u ________ 320 u ........ 200 u ........ 320 p ________ 330 M ________ 340 u ________ 380 p. ________ 290 It Thickness of outer wall ............................ 20 u ......... 30—40 u ______ 20 p _________ 20 p _________ 20 p. ......... 20 a ......... 20 p ......... 20—30 :4 Equatorial layer: Height at center ___________________________________ 120 p ________ 120 u ________ 100 u ........ 120}: ________ 120 [a ........ 130 u ........ 120 n ________ 110 [A Height at periphery ................................ 660 u ________ 720 p ________ 440+ u ______ Broken ______ Broken ...... Broken ______ Broken ______ 500 u Lateral chambers: ‘ Number ........................................... 8 ............ 9 ____________ 10 ........... 8 ____________ 7 ____________ 10 ___________ 9 ............ 7 Length ............................................ 140—240u.. _ 1W280p..._ l40—280p.... 200—280;:..._ 140—260 51.... 120—280n._._ 140—340 IL“— 140-280;; Height ............................................. 20-80 ,1: ...... 50-70 M. ...... 20—60 u ______ 40~80 M ...... 40-60 M. ...... 50-80 It ______ 30-60 in ...... 30-60 u Thickness of roofs and floors ........................ 20 y _________ 20 p _________ 20 p _________ 20 u _________ 20 u ......... 20 u _________ 20 ,r _________ 20 ,u. Surface diameter of pillars ............................. 60-80 u ...... 80 p. ......... 100 p ________ 80 u ......... 60 It _________ 100 [l ........ 60-80 H ...... 100 u 5 990815—52 30 Occurrence.-—Locs. 11a, 30, 37, 38, 43, 53, 121, 123. Distribution elsewhere: Upper Oligocene of Antigua. Remarks—Lepidocyclina (Nephrolepidina) verbeeki Barker (1932, pp. 278, 279, pl. 16, figs. 2, 3, 5, not figs. , 1, 4), [not Newton and Holland, 1875], from the Oli- gocene of San Pedro, Peru, is without question L. vaughani. In Peru this species occurs with Miogypsina (Miolepidocycl’ina) panamensis (Cushman). Subgenus EULEPIDINA H. Douvillé, 1911 Lepidocyclina (Eulepidina) favosa Cushman 1 Plate 22, figures 1—5 1919. Lepidocyclina favosa Cushman, Carnegie Inst. Washington Pub. 291, p. 66, pl. 3, figs. 1b, 2; pl. 15, fig. 4. 1945. Lepidocyclina (Eulepidina) favosa Cushman. Cole, Flor- ida Geol. Survey Bull. 28, pp. 41—43, pl. 4, figs. 3, 4, 7, 11; pl. 8, figs. 1, 2; pl. 9, figs. 1—7; pl. 10, figs. 1-9; pl. 11, fig. 9 (references and synonymy). Lepidocyclz'na (E) favosahas been discussed in deta'1 ‘by Vaughan (1933), pp. 37—41) and later by Cole (1945, pp. 41—43). An equatorial and a vertical section of megalospheric individuals are figured, also several sections of micro- . spheric individuals. In the material available the microspheric generation appears to be the common one, but this may be due to the manner in which the speci— mens were selected. Occurrence—Loos. 38, 39. The same as that of L. undosa. Distribution elsewhere: Lepidocyclina (Eulepidina) undosa Cushman Plate 22, figures 6—8 1919. Lepidocyclina undosa Cushman, Carnegie Inst. Washing- ton Pub. 291, p. 65, pl. 2, fig. 1a. 1945. Lepidocyclina (Eulepidina) undosa Cushman. Cole, Flor- ida Geol. Survey Bull. 28, pp. 43, 44, pl. 1, figs. 14, 15; pl. 2, fig. 8; pl. 8, fig. 7; pl. 11, fig. 8. (references and synonymy). The equatorial sections of Lepidocyclina favosa and L. undosa are similar. The differences occur in the vertical sections. At most localities these two species occur together. It is extremely probable that only one highly variable species is represented, and that L. gigas Cushman is the microspheric form of the combined species. Although L. undosa is found only at locality 45 in Panama, it may occur at localities 38 and 39 at which L. favosa is found. Few specimens were recovered from these localities and these with some difiiculty be— cause of the indurated nature of the matrix material. Occurrence—Loo. 45. Distribution elsewhere: Up- per Oligocene in the Antigua formation of Antigua; Moneague formation of Jamaica; limestone of Cayman Brac, Cayman Islands; Meson formation of Mexico; Chickaswhay limestone of Alabama; Suwanee limestone of Florida; San Luis series of Venezuela; and in Trinidad. EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE Lepidocyclina gigas Cushman Plate 22, figure 9 1919. Lepidocyclina gigas Cushman, Carnegie Inst. Washington Pub. 291, p. 64, pl. 1, figs. 3—5; pl. 5, fig. 4. 1945. Lepidocyclina gigas Cushman. Cole, Florida Geol. Sur— vey Bull. 28, pp. 44, 45, pl. 8, figs. 5, 6 (references and synonymy). Vaughan (1924, p. 799) as early as 1924 expressed the opinion that Lepidocyclina gigas is the microspheric generation of L. undosa. As L. undosa and L. favosa occur together, L. gigas could be the microspheric gen- eration of one or the other. However, if L. undosa and L. favosa are combined, L. gigas is the microspheric generation of the combined species. Although this is undoubtedly the correct relationship, the name L. gigas is used in this report because of the tentative retention of the specific names, L. undosa and L. favosa. Occurrence.——Loc. 39. Distribution elsewhere: The same as that of L. undosa. Subfamily HELICOLEPIDINAE Tan Genus HELICOLEPIDINA Tobler, 1922 Helicolepidina spiralis Tobler Plate 24, figures 1—16; plate 20, figure 13 Helicolepidina spiralis Tobler, Eclogae geol. Helvetiae, vol. 17, pp. 380-384, text figs. 1—3. Helicolepidina spiralis Tobler. Barker, Jour. Paleontol- ogy, vol. 8, pp. 345, 346, pl. 47, figs. 1—4; text figs. 1a, 0 (references and synonymy). Helicolepidina spiralis Tobler. Barker and Grimsdale, idem, vol. 10, p. 243, pl. 33, fig. 7. Helicolepidina spiralis Tobler. Vaughan, idem, vol. 10, p. 251, pl. 39, fig. 5; pl. 40, figs. 6—8. Helicolepidina nortom' Vaughan, idem, vol. 10, pp. 248—251, pl. 39, figs. 1—4; pl. 40, figs. 1—5. Helicolepidina spiralis Tobler. Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p. 76, pl. 45, fig. 1. Helicolepidina spiralis Tobler. Cole, Jour. Paleontology, vol. 23, p. 272, pl. 52, figs. 9, 10. 1922. 1934. 1936. 1936. 1936. 1941. 1949. Three topotypes of Helicolepidina nortoml Vaughan from Louisiana are illustrated for comparison with the Panamanian specimens identified as H. spiralis Tobler. Vaughan (1936, p. 251) wrote, “The principal difference, however, seems to be in the spiral chambers of H. nortom' not extending so clearly to the embryonic chambers as in H. spiralis.” In preparing equatorial sections of several specimens of H. spiralis, one finds that the extent of the spiral chambers in the plane of the equatorial section depends on the accuracy with which the section is ground. This relationship is shown by figures 7—10 on plate 24. Occurrence.—Locs. 22a, 124, 125, 132, 145. Distribu- tion elsewhere: Upper Eocene in Trinidad, the Seroe di Cueba limestone of Curacao; northwest Peru; Vene- zuela; the Tampico Embayment, Mexico; Louisiana (as H. nortom') and in the L. chapem' zone (= L. fragilis) of Florida (Wayne Moore, personal communication). FAMILY DISCOCYCLINIDAE 31 Family DISCOCYCLINIDAE Genus ASTEROCYCLINA Gumbel, 1870 Asterocyclina georgiana (Cushman) Plate 27, figures 6—12 1917. Orthophragmina georgiana Cushman, U. S. Geol. Survey Prof. Paper 108—G, pp. 117, pl. 41, figs. 2, 3; pl. 42, fig. 3; pl. 43, figs. 2, 3. 1949. Asterocyclina georgiana (Cushman). Cole, J our. Paleontol- ogy, vol. 23, pp. 273, 274, pl. 52, figs. 7, 8; pl. 53, fig. 1; pl. 55, figs. 1—5. Some typical specimens of Asterocyclina georgiana, have 4 rays projecting from a central area, and others have in addition to these an extension of the equatorial layer between the rays. Such specimens have a quadrangular outline. ' Occurrence—Loos. 22a, 124, 125, 137, 145. Distri- bution elsewhere: Upper Eocene of Florida, Cuba, Jamaica, Venezuela, and Nicaragua. Asterocyclina mariannensis (Cushman) Plate 27, figures 1—-5; plate 28, figures 1—3 1917. Orthophmgmina mariannensis Cushman, U. S. Geol. Sur— vey Prof. Paper 108—G, pp. 116, 117, pl. 40, fig. 5; pl. 42, fig. 2. 1917. Orthophragmina mariannensis Cushman, var. papillata Cushman, idem, p. 117, pl. 43, fig. 1; pl. 44. 1920. Orthophragmina mariannensis Cushman. Cushman, U. S. Geol. Survey Prof. Paper 125, p. 46, pl. 11, fig. 1. 1920. Orthophragmina mariannensis Cushman, var. papillata Cushman. Cushman, idem, p. 47, pl. 11, fig. 2. 1945. Discocyclina, (Asterocyclina) mariannens'is (Cushman). Vaughan, Geol. Soc. America Mem. 9, pp. 80—82, pl. 28; pl. 29. Test stellate, composed of a small, pronounced central umbo from which radiate 5 or 6 raised rays between which there are more or less flat interray areas. Some specimens have large, raised papillae in the umbonal area and papillae of similar size and shape on the raised portions of the rays. Other specimens have small, indistinct papillae on the umbonal area and rays. In both types the interray areas are either devoid of papillae, or the papillae are very small and widely scattered. A polygonal mesh of ridges occurs among the papillae and on the interray areas. The largest specimen available has a diameter of 6 mm, but com- plete specimens would have a much greater size; every specimen recovered has chipped outer edges. Four equatorial sections were studied, one of which represents a microspheric individual. One of the sec- tions of a megalospheric individual is moderately satisfactory, another does not quite penetrate to the equatorial plane at the embryonic chambers, and the third is entirely unsatisfactory. The least satisfactory section of the embryonic chambers shows large bilocular embryonic chambers. The initial chamber has diameters of about 240 by 340 ,u. The second chamber has diameters of 260 by 420 #- The distance across both chambers is 520 M- The outer wall of the chambers is only about 10 u thick. The periembryonic chambers are too indistinct to describe. The other section shows large bilocular embryonic chambers. The initial chamber has diameters of 310 by 440 ,u and the second chamber has diameters of 340 by 520 u. The distance across both chambers is 660 u. The outer wall is about 10 u thick and is composed of an outer and inner layer between which there is a very fine canal (pl. 28, fig. 3). There are several periem- bryonic chambers. At one end of the partition between the embryonic chambers is a very large periembryonic chamber having diameters of 50 by 340 p. The peri- embryonic chamber at the other end is much smaller, 70 by 140 ,u. On the outer periphery of the larger embryonic chamber are 4 periembryonic chambers, 2 on one side and 2 on the other. Between these two sets of chambers there are 4 small square chambers. The periembryonic chambers on the outer margin of the initial chamber are too indistinct to be described. The equatorial chambers are arranged so that the stellate pattern of the test is repeated in the arrange- ment of the equatorial chambers. One of the equatorial sections shows 5 rays and the other 6 rays. The equatorial chambers in the rays have radial diameters as long as 100 u and tangential diameters of 10 to 20 ,u. Equatorial chambers in the interray posi- tion have radial diameters of 40 ,u and tangential diam- eters of 20 u. ' The three vertical sections available are made from specimens broken in removal from the matrix material and now incomplete. The cavities of the lateral chambers are long and low, with moderately thick roofs and floors. In two of the sections the lateral chambers are arranged in very regular tiers, but in the third section the lateral cham- bers are arranged in regular tiers for about three- quarters of the distance from the embryonic chambers to the periphery and then they overlap from one tier to the adjacent one. Two of the vertical sections have heavy pillars ir- regularly distributed in the umbonal area and extending from the embryonic chambers to the surface of the test. The third section also has heavy pillars, but these do not extend beyond the beginning of the outer zone of overlapping lateral chambers. Actually the pillars may extend to the surface and are not visible because the section may be slightly oblique; smaller pillars extending from the embryonic chambers to the surface would seem to bear this out. Occurrence—L00. 140. Distribution elsewhere: Up- per Eocene of Florida and Cuba. Remarks—The specimens from Panama are similar in all respects to those from the vicinity of Nuevitas, Cuba, assigned by Vaughan (1945, pp. 80—82) to Asterocyclinc mariannensis (Cushman). As Vaughan has noted, there is a difference in the shape and arrange- 32 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE Measurements of vertical sections of Asterocyclina mariannensis from locality 140 l l Specimen 1 2 ‘5 Actual diameter ______________________________________________ 3.4 mm _____________ 5.0 mm _____________ 4.8 mm Diameter of the umbo _________________________________________ 1.2 mm _____________ 2.0 mm _____________ 2.0 mm Thickness through center ______________________________________ 1.1 mm _____________ 1.8 mm _____________ 1.8 mm Flange thickness at juncture with umbo _________________________ 0.66 mm ____________ 0.72 mm ____________ 0.9 mm Flange thickness at outer edge _____________________________________________________ 0.24 mm ____________ Embryonic chambers: Length __________________________________________________ 440 u ______________ 540 u ______________ 420 ,u Height __________________________________________________ 220 y. ______________ 160 y. ______________ 280 [1. Thickness of outer wall ____________________________________ 10 ,u _______________ 10 u _______________ 10 u Equatorial layer: Height at center __________________________________________ 40 ,u _______________ 60 u _______________ 55 u Height at periphery ___________________________________________________________ 60 u _______________ Lateral chambers: 'Number _________________________________________________ 16 _________________ 25 _________________ 29 Length __________________________________________________ 40—80 It ____________ 140—200 a __________ 60—100 u Height __________________________________________________ 10—15 M ____________ 5—15 ,u _____________ 5—15 ,1 Thickness of floors and roofs _______________________________ 10 a _______________ 10—20 M ____________ 10—20 ,1 Surface diameter of pillars in umbo _____________________________ 80—160 9 ___________ 100—180 a __________ 80 a Surface diameter of pillars in flange _____________________________ 100 p ______________ None; _____________ 60 u ment of the embryonic chambers between the typical ‘ specimens from the Ocala limestone of Florida and those from Cuba. The specimens from Panama have embryonic cham- bers which resemble those found in the Cuban speci- mens, but none of the specimens from Panama has nmbryonic chambers similar to specimens from Florida. Asterdcyclina minima (Cushman) Plate 26, figures 1—20; plate 28, figures 4—6 1919. Orthophragmina minima Cushman, U. S. Nat. Mus. Bull. 103,pp.97,98,pl.41,fig.1. Orthophmgmtna sculpturata Cushman, Carnegie Inst. Washington Pub. 291, pp. 54, 55, pl. 9, figs. 8, 9. Orthophragmina minima Cushman. Cushman, U. S. Geol. Survey Prof. Paper'125, p. 41, pl. 7, fig. 3. Orthophmgmina sculpturata Cushman. Cushman, idem, p. 43, pl. 8, figs. 3—7. Discocyclina minima (Cushman). America Bull., vol. 35, p. 792. Discocylina sculpturata (Cushman). p. 793. Asterodiscocyclina stewarti Berry, Eclogae geol. Helvetiae, vol. 21, pp. 405—407, pl. 33. , Discocyclina (Asterocyclina) kugleri Gravell, Smithsonian Misc. Coll., vol. 89, no. 11, pp. 23, 24, pl. 3, figs. 1—5. Discocyclina (Asterocyclina) kugleri Gravell. Rutten, Jour. Paleontology, vol. 9, p. 542, pl. 62, fig. 1. Discocyclina (Asterocyclina) vermunti Rutten, idem, p. 542, pl. 61, figs. 4, 5; pl. 62, fig. 7. Discocyclina (Asterocyclina) sp. Rutten, idem, p. 542, pl. 62, fig. 6. Discocyclina (Discocyclina) minima (Cushman). Vaughan, Geol. Soc. America Mem. 9, p. 76, pl. 25, figs. 4—7. Discocyclina (Discocyclina) sp. cf. D. (D.) minima (Cush- man). Vaughan, idem, p. 77, pl. 25, fig. 8. 1919. 1920. 1920. 1924. Vaughan, Geol. Soc. 1924. Vaughan, idenn 1928. 1933. 1935. 1935. 1935. 1945. 1945. 1945. Discocyclina (Asterocyclina) ruttem’ Vaughan, idem, pp. 82, 83, pl. 30, figs. 1—5. 1945. Discocyclina (Asterocyclina) sculpturata (Cushman). Vaughan, idem, pp. 83—85, pl. 30, fig. 6; pl. 31. Disco’cyclina (Discocyclina) minima (Cushman). Cole, Jour. Paleontology, vol. 23, p. 273, pl. 52, fig. 14; pl. 54, figs. 6,7; pl. 55, fig. 6. 1949. In 1919 Cushman (1919b, p. 54) described Orthophrag- mine sculpturata from Nuevitas, Cuba. Two illustra— tions are given of this new species, one an oblique “vertical” section, and the other an oblique “equato- rial” section. The oblique “vertical” section has a diameter of about 4 mm. The inflated central portion has a diameter of 1.5 mm and a thickness through the center of about 1 mm. Three rays are shown. The best developed ray has a length of about 1.8 mm and a thickness of about 0.2 mm. The central, umbonal portion has heavy pillars, and relatively long lateral chambers are arranged in regular tiers between the pillars. The oblique “equatorial” section has a maximum diameter of about 2.5 mm. Heavy pillars Occur in the umbonal area. ' Later, Cushman (1920, p. 43) republished the descrip- tion and the original illustrations of 0. sculpturata. To these he added three more illustrations, one of an external View of a specimen from the type locality at Nuevitas and the others of two vertical .sections of specimens from the Gloria mine, Oriente Province, Cuba. Neither the type illustrations nor the supple- mental ones present an adequate picture of this species. Willard Berry (1928, p. 406) described a new genus, Asterodiscocyclina, for a new species from a locality near Calita Sal, Department of Piura, Peru. This new species, A. stewartl, is not compared to any pre- viously described species. Gravell (1933, p. 23) in the description of a new species of Asterocyclina, A. kugleri from the upper Eocene of Venezuela, compared it to A. stewam’ (Berry) in the following sentence: “It (A. kuglem') has distinct Asterocyclina arms, although they are small and often broken off, and its test is thicker than that of D[isco- cyclina] (Asterodiscocyclina) stewarti Berry.” FAMILY DISCOCYCLINIDAE 33 Cole and Ponton (1934, p. 141) reported a new species of Asterocyclina, A. monticellensis, from the Southern States Oil Corporation well in Jefferson ' County, Fla. Later, Cole (1944, p. 76; 1945, p. 122) recorded the presence of this species in two other Floridian wells. In all of these wells this species is assumed to occur in strata assigned to the middle Eocene. Rutten (1935, p. 542) identified A. kugleri Gravell from upper Eocene strata of Cuba. From the same locality he described a new species, Discocycl’ina (Asterocyclina) vermunti and illustrated another prob- able species of Asterocyclina, without giving it a name. Recently, Vaughan (1945, pp. 80, 82) reexamined and described species of Asterocyclina from Cuba. From a locality “4.5 kilometers west of Guanajay on the road to Mariel (Palmer 1102)” Vaughan reported A. sculpturata and a new species, A. ruttem’. As the late Mrs. Dorothy Palmer had sent me material from this station, it was possible to study specimens similar to those described by Vaughan. All of these species are characterized in vertical sec— ‘tion by the presence of many open lateral chambers having thin floors and roofs and arranged in regular tiers. Certain of the species have heavy pillars, whereas others are described as not possessing pillars. Although all of the species have the equatorial cham— bers arranged so that equatorial sections show rays, arms are developed externally only in the peripheral area. In certain species the external rays are so weakly developed that they are either not apparent or appear as very slight undulations. A rim may or may not be present. Vaughan (1945, p. 83) distinguished A. ruttem' from A. stewarti and A. kugleri by the presence of large papillae and pillars in the first species. Although Vaughan does not specifically compare A. rutteni with A. sculpturata except in shape of the pillars, A. ruttem’ has few and large papillae, whereas the papillae of A. sculpturata are smaller and are arranged in a different pattern. Moreover, A. scupturata has better developed rays and these extend higher on the umbo. Although it is entirely possible to distinguish cer- tain specimens of A. ruttem' (pl. 26, fig. 1), from others which may be assigned to A. sculpturata (pl. 26, fig. 4) by external appearance, the differences on which this identification is made disappear when thin sections alone are studied. For example, Vaughan (1945, pp. 83, 85) wrote of A. ruttem', “The section cuts two nodules longitudinally, the larger is 0.29 mm thick at the surface; and there are some smaller pillars.” Of the pillars of A. sculpturarta he recorded, “Pillars are well developed, some of them are large, as much as 28011 thic .” It would seem, therefore, that the surface diameter of the pillars in the two species is virtually the same. However, Vaughan (1945, p. 85) stated concerning A. sculpturata: ' As seen in longitudinal section the pillars have pointed inner ends and soon attain their maximum diameter which is main- tained with only slight change to the surface. This differs from the longitudinal sections of the nodules of D [iscacyclina] (A.) ruttem' It should be noted that Vaughan had only one vertical section of each of these species. Moreover, neither of these sections passes through the center. If Vaughan had had several accurately oriented vertical sections, he would have been able to observe that thelpillars in these two species are the same. V V Also, in the Cuban sample there are many specimens which externally appear to be intermediate between A. rutteni and A. sculpturata. In every character examined, these species appear to be alike. There remains, however, the question whether such species as A. kuglem', which is desc1ibed as not possessing pillars, should be included in A. sculpturatd. Rutten (1935, p. 528) recorded A. kugleri as a rare species occurring at the same locality as A. vermunti, a species which Vaughan correctly considered to be A. sculpturata. It is entirely possible for a species which has pillars not to show these externally because the surface of the test may be worn. Also, it is not unusual for a test to be sectioned in a way that does not reveal the pillars, as the writer has observed on many occasions. Micro— paleontologists should themselves make their thin sections so that they can study the internal features as the section is being ground. The presence or absence of pillars 1s not a firm cri- terion on which to base a species. It has been proven _ with too many species that there is individual variation from very weak pillars to exceptionally strong ones. Inasmuch as A. kugleri and A. sculpturata occur in the same samples and inasmuch as they are identical in all internal structures except that of pillars, these species should be combined. The description and illustrations of A. stewarti are not good, but it would seem that A. stewarti is another synonym of A. sculpturata. Finally, Orthophmgmina minima Cushman (1919a, p. 41) from the upper Eocene of Panama should be discussed. The holotype of this species isa single, not centered, vertical section. New illustrations of this specimen are given on plate 26, figures 14, 15. Figure 14 is a photomicrograph taken by ordinary transmitted light and figure 15 is the same specimen. photographed by dark field illumination. These excellent photographs were made by Mr. Lloyd Henbest of the U. S. Geologi- cal Survey. Vaughan (1924, p. 792) assigned 0. minima. to the genus Discocyclina s. s. Recently, Vaughan (1945, pp. 76, 77) briefly discussed this species, refigured the holotype, and gave illustrations of three additional specimens from the type locality of this species. In 34 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE addition, he illustrated a single vertical section of a specimen from Jamaica which he compared with D. (D.) minimal. Cole (1949, p. 273) figured 4 not centered, vertical sections of Specimens from the upper Eocene of Panama which he considered should be referred to' D. (D.) minima. . With the exception of the single highly oblique “equatorial”~ section illustrated by Vaughan, all the other sections are vertical ones. It became apparent when the holotype was photographed by dark field illumination that it displayed all the internal features of A. sculpturata. Reexamination of other specimens with this point in mind demonstrates the uniform similarity between the specimens referred to D. minima and those assigned to A. scalpturata. It appears, therefore, that the species called D. minima is the same as A. sculpturata. Inasmuch as the specific name, A. minima, has priority over all the other names, the entire group must be called A. minima. Although Asterocyclina monticellensis from the as- sumed middle Eocene strata of Florida is related closely to A. minima, it would appear that the two species can be distinguished. A. monticellensis is smaller, it has fewer lateral chambers to a tier, and more important, the floors and roofs of these lateral chambers are slightly curved, Whereas those of A. minima are straight. Measurements of equatorial sections of Asterocyclina minima . Locality 140 22a Specimen 1 2 3 4 Diameter _____________________________________ 3.5 mm __________ 2.34 mm _________ 2.9 mm __________ 2.82 mm Embryonic chambers: , Diameters of initial chamber ________________ 120x 120 u _______ 110x 160 p _______ 100>< 140 M _______ 100x 125 :1 Diameters of second chamber ________________ 100>< 180 a _______ 120x 220 M _______ 130x230 u _______ 110x 220 a Distance across both chambers ______________ 220 p ____________ 250 u ____________ 240 p- _ _ _ _ _ _ _ _ _ _> _ 220 a Thickness of outer wall _____________________ 10 p. _____________ 10 p___________1_ 5 p ______________ 5 u Equatorial chambers: Chambers in rays: Radial diameter _____ ' __________________ 80 ,u _____________ 60 M _____________ 80 a _____________ 60 u Tangential diameter ____________________ 15 u- -’ ___________ 20 p _____________ 20 a _____________ 20 a Chambers in interray areas: Radial diameter _______________________ 40 ,u _____________ 40 p ,,,,,,,,,,,,, 40 a _____________ 80 ,u Tangential diameter ____________________ 10 ,u _____________ 15 a _____________ 20 a _____________ 20 u Measurements of vertical sections of Asterocyclina minima Locality 140 229. Specimen 1 2 3 4 5 Diameter _____________________________________ 2.0 mm ______ 3 3 mm ______ 4 6 mm ______ 2.26 mm _____ 1.56 mm Diameter of umbo _____________________________ 1.7 mm ______ 2 1 mm ______ 3.2 mm ______ 1.92 mm _____ 1.4 mm Thickness through center _______________________ 1.14 mm _____ 1.5 mm ______ 2.36 mm _____ 1.21 mm _____ 0.9 mm Thickness of rim ______________________________ 0.1 mm ______ 0.32 mm _____ 0.26 mm _____ 0 2 mm ______ 0.1 mm Embryonic chambers: Length ___________________________________ 180 p. ________ 200 ,u ________ 170 u ______________________ 100 [1. Height ___________________________________ 120 u ________ 120 ,u ________ 120 u ______________________ 80 in Thickness of outer wall _____________________ 10 ,u _________ 5 a __________ 5 a ________________________ 5 a Equatorial layer: Height at center ___________________________ 30 ,u _________ 40 a _________ 20 p ......... 25 p. _________ 25 p. Height at periphery ________________________ 40 a _________ 65 p _________ 40 ,u _________ 60 a _________ 40 u Lateral chambers: Number __________________________________ 16 ___________ 24 ___________ 35 ___________ 18 ___________ 15 Height ___________________________________ 20 ,u. _________ 10—20 ,a ______ 10—20 ,u ______ 20—30 M ______ 20 1:. Length ___________________________________ 40—60 a ______ 60—100 a _____ 60—140 ,u _____ 80—100 a _____ 80 a Surface diameter of pillars ______________________ 100—200 a- _ _ _ 60—200 [1. _____ 140—320 14- _ _ _ 100—160 a- _ _ _ 80—180 It FAMILY MIOGYPSIN IDAE Vertical sections of Cuban specimens (pl. 26, figs. 8—13) of A. sculpturata and A. rutteni are illustrated to demonstrate how these two species intergrade and for comparison with similar Panamanian specimens. Occurrence.~Locs. 22a, 140. Distribution elsewhere: Upper Eocene of Cuba (as A. sculpturata, A. eermunti and A. rutteni), Venezuela (as A. kuglem'), Jamaica (as D. minima), and Peru (as A. stewarti). Genus PSEUDOPHRAGMTNA H. Douvillé, 1923 Subgenus PROPOROCYCLINA Vaughan and Cole, 1940 Pseudophragmina (Proporocyclina) flintensis (Cushman) Plate 28, figures 7—16 1917. Orthophragmina fi'i'ntensis Cushman, U. S. Geol. Survey Prof. Paper 108—G, p. 115, pl. 11, figs. 1, 2. 1945. Pseudophragmina (Proporocyclina) fiintensis (Cushman). Vaughan, Geol. Soc. America Mem. 9, pp. 89—92, pl. 36; pl. 37, fig. 1. 1949. Pseudophragmina (Proporocyclina) fiintensis (Cushman). Cole, Jour. Paleontology, vol. 23, p. 274, pl. 54, figs. 1—4. The description which follows is based on specimens of Pseudophragmina (P.) fiintensis from locality 140. Test thin, fragile, compressed, with a small umbonal area which is surrounded by a thinner rim. Surface ornamentation consists of concentric circles of small, sharp papillae which are the same from the central area to the periphery of the test. The embryonic chambers are bilocular. The initial chamber is circular with an internal diameter of about 40 p. The second chamber has internal diameters of 55 by 80 p. and very slightly embraces the initial chamber. The distance across both chambers is 95 p. The embryonic chambers are completely surrounded by a ring having 11 periembryonic chambers. The equatorial chambers near the center of the test are square, but they become radially elongated toward the periphery. Chambers near the periphery have radial diameters of about 100 p and tangential diameters Measurements of vertical sections of Pseudophragmina flintensis Specimen 1 2 Diameter _____________________ 3.8 mm ______ 3.4 mm Diameter of umbo _____________ 0.7 mm ______ 0.96 mm Thickness at center ____________ 0.52 mm _____ 0.46 mm Thickness of flange near umbo--- 0.4 mm ______ 0.32 mm Thickness of flange at periphery- 0.2 mm ______ 0.18 mm Embryonic chambers: Length ___________________ 65 u _________ 60 u Height ___________________ 35 ,u. _________ 40 1; Thickness of outer wall _____ 4 ,u __________ 5 p Equatorial layer: Height at center ___________ 40 u _________ 30 u .. Height at periphery ________ 40 u _________ 55 1!: Lateral chambers: Number __________________ 10 ___________ 8 Length ___________________ 30—40 a ______ Height ___________________ 5 u __________ 5 u Thickness of roofs and floors- 10 u _________ 5—10 )1 Surface diameter of pillars ______ 30 u _________ 20 u 35 of about 40 p. The radial chamber walls are complete and in alinement. The annular stolon is at the distal end of the radial chamber walls. The cavities of the lateral chambers are slitlike be- tween thick roofs and floors. The lateral chambers are not in definite tiers. Occurrence—Low. 124, 140. Distribution elsewhere: Occurrence of specimens which probably represent this species are given under the discussion. Remarks—«As Vaughan (1945, pp. 88) clearly stated, there are five upper Eocene species of Pseudophmgmina, (Proporocyclina) which are closely related. These are P. (P.) flintensis (Cushman) from Florida, Cuba, and Panama; P. (P.) citrensis (Vaughan) (1928, .p. 159) from Florida; P. (P.) mirandana, (Hodson) (1926, p. 8) from Trinidad and Venezuela; P. (P.) tobleri Vaughan and Cole (1941, p. 62) from Trinidad; and P. (P.) blumenthali (Gorter and van der Vlerk) (1932, p. 111) from Venezuela. Vaughan discussed these species in detail and gave a diagnostic key for their identification. The differences among the species are slight. Although there were not enough specimens from Panama to make a large suite of oriented thin sections, there is a suggestion that these species should be com- bined, with the possible exception of P. (P.) tobleri. Vaughan (1945, p. 89) indicated this idea also when he wrote, “It seems probable that P. (P.) citrensis is a small, perhaps immature, varietal form of P. flintmsis, representing the umbonal part of the test of that species. P. (P.) mirandana is similar except that it is nonumbonate.” It is extremely doubtful that devel- opment of the umbo or lack of an umbo is a reliable character for distinguishing species. Family MIOGYPSINIDAE Genus MIOGYPSI-NA Sacco, 1893 Subgenus MIOGYPSINA Sacco, 1893 Miogypsina (Miogypsina) antillea (Cushman) Plate 24, figure 17; plate 25, figures 13—15 1919. Heterosteginoides panamensis Cushman, U. S. Nat. Mus. Bull. 103, p.‘ 97, pl. 43, figs. 1, 2 [not figs. 3—8]. Heterosteginoides antillea Cushman, Carnegie Inst. Wash- ington Pub. 291, p. 5, pl. 5, figs. 5, 6. M iogypsina cushmam' Vaughan, Geol. Soc. America Bull., vol. 35, p. 813, pl. 36, figs. 4—6. Miogypsina bramlettez’ Gravell, Smithsonian Misc. COIL, vol. 89, no. 11, pp. 32—34, pl. 6, figs. 5—10. M iogypsina antillea (Cushman). Vaughan and Cole, Geol.‘Soc. America Spec. Paper 30, pp. 78, 79, pl. 45, figs. 5—7. M iogypsina cushmam’ Vaughan. Cole, Florida Geol. Survey Bull. 19, pp. 47, 48, pl. 17, figs. 3—5. 1919. 1924. 1933. 1941. 1941. Test small, with a length of 1.6 to 1.8 mm and a width of 1.3 to 1.5 mm. Its maximum thickness is from 0.7 to 0.8 mm. Its surface is covered with small, slightly raised papillae. The embryonic chambers are bilocular, the initial chamber is circular to subcircular, with internal di- \ 36 ameters of 100 by 110 M in one specimen and 120 by 140 M in another specimen. The second chamber is slightly reniform, with internal diameters of 100 by 140 M in one specimen and 95 by 160 M in the other. There is a partial coil of- rudely subquadrate periem— bryonic chambers which surrounds the embryonic chambers on the distal side. Six of these chambers appear in one specimenzand 8 in the other. The equatorial chambers are diamond shaped. Those near the distal margin have radial diameters of 60 to 140 M and tangential diameters of 50 to 100 M. A well-oriented vertical section has embryonic chambers 200 M long and 100 M high. The equatorial layer has a height of 65 M near the embryonic chambers and a height of 100 M at the distal margin of the test; these measurements include the thickness of the floors and roofs. The lateral chambers occur in regular tiers between the pillars, but where pillars are not developed, the chambers overlap. In the thickest portion of the test there are about 8 lateral chambers to a tier on each side of the equatorial layer. The lateral chambers have open cavities with a height of about 18 M and the .floors and roofs have thicknesses of about 10 M. Fine pillars with a surface diameter of about 60 M are present. Occurrence.—Locs. 37, 53. Distribution elsewhere: Upper Oligocene in Anguilla, Venezuela, and the Marathon well on Key Vaca, Florida. Remarks—Vaughan and Cole (1941, pl. 45, figs. 5—7) EOCENEV AND OLIGOCENE LARGERTFORAMINIFERA IN THE CANAL ZONE figured three topotypes of this species. The vertical section which they illustrate is not centered and is comparable to the one of a Panamanian specimen given as figure 13, plate 25. These sections are almost iden- tical. Also, the equatorial sections of the specimens from Anguilla and Panama are identical. N 0 criteria are known for distinguishing, this species from those from Venezuela which were named M. bramlettei by Gravell. Also, it is entirely probable that M. hawkinsi Hodson (1926, p. 28) should be combined With M. antillea. However, this 'problem’ requires more study than can be given at the present time. Subgenus MIOLEPIDOCYCLINA A. Silvestri, 1907 Miogypsina (Miolepidocyclina) panamensis (Cushman) Plate 25, figures 1—8 1919. Heterosteginoides panamensis Cushman, U. S. Nat. Mus. Bull. 103, p. 97, pl. 43, figs. 3—8 [not figs. 1, 2]. M iogypsina panamensis (Cushman). Vaughan, Geol. Soc. America Bull., vol. 35, pp. 802, 803, 813, pl. 36, fig. 7. Miogypsina afl". panamensis (Cushman). Mag., vol. 69, pp. 280, 281, pl. 16, fig. 7. M iolepidocyclina ecuadorensis Tan, De Ing. in Ned.- Indié, 4. Mijnb. en Geol., 3 Jaarg., p. 58. M iogypsina (M iolepidocyclina) panamensis (Cushman). Vaughan and Cole, Geol. Soc. America Spec. Paper 30, p. 78. . 1947. Heterosteginoides panamensis Cushman. Hanzawa, Jour. Paleontology, vol. 21, pp. 260—263, pl. 41, figs. 1—13. 1924. 1932. Barker, Geol. 1936. 1941. The following tables give measurements of the inter- nal features of Miogypsina (M.) panamensis. Measurements of equatorial sections of Miogypsina (Miolepidocyclina) panamensis from locality 55 Length __________________________________ 1.8 mm__-_ 1.64 mm_-- 1.3 mm-_-_ 1.6 mm__-- 1.7 mm-___ 1.84 mm Width ___________________________________ 1.6 mm____ 1.5 mm---_ 1.2 mm-_-- 1.4 mm____ 2.0 mm___- 2.0mm Embryonic chambers: Diameters of initial chamber ___________ 100 M ______ 105 M ______ 80X 100 M- _ 80X 90 M- _ - 105>< 120 M_- 80 M Diameters of second chamber _____________ 70X 120 M___ 65X 100 M--- 70X 100 M--_ 40X 90 M--- - 55X 100 M--- 60X 60 M Distance across both chambers-"1 ______ 180 M ______ 185 M ______ 160 M ______ 140 M ______ 170 M ______ 165 M Distance from periphery of test to edge 0.28 mm_-_- 0.34 mm---_ 0.3 mm- - - _ 0.4 mm_ _ _ _ 0.4 mm__ _ _ 0.3 mm of initial chamber. Number of coils made by periembryonic 1%; __________ 1%--_ _ - _ - - _ 11/2 __________ 1% _________ 1% _________ 1% chambers. Number of periembryonic chambers _____ 11 _________ 16 _________ 16 _________ 15 _________ 17 _________ 15 Equatorial chambers: Radial diameter _______________________ 100 M ______ 70 M _______ . 90 M _______ 120 M ______ 105 M ______ 100 M Tangential diameter ___________________ 70 M _______ 50—80 M- _ _ - 70 M _______ 80 M _______ 90 M _______ 70 M Measurements of vertical. sections of . Miogypsina (Miolepidocy— clina) panamensis from locality 55 Length _________________________ 1.3 mm_ _ _ _ 1.6 mm Thickness _______________________ 0.7 mm_ _ _ _ 0.54 mm Embryonic chambers: Length _____________________ 220 M ______ 180 M Height_____---_--_-- ....... 105M ______ 140M Distance from proximal edge 0.36 mm___ 0.4 mm to edge of initial embryonic chamber. Equatorial layer: Height at proximal edge ______ 120 M ______ Height at distal edge _________ 140 M ______ 120 M Lateral chambers: Number ____________________ 5 __________ 4 Length _____________________ 60—100 M- - - 40—60 M Height- - _ _ - _ _ f _____________ 20—60 M- - - _ 20—30 M Thickness of floors and roofs- - 20—40 M- _ - - 20 M Surface diameter of pillars -------- 60 M _______ 40—60 M Occurrence—Loo. 55. Distribution elsewhere: Oli- gocene of Ecuador. RemarksL—Two species referred to the subgenus Miolepidocyclina have been described from America, the species under discussion and M. (M.) mexicana Nuttall (1933, p. 175) from the Alazan formation of Mexico.- Several thin sections of the Mexican form are illustrated (pl. 25, figs. 9—12) for comparison with the Panamanian form. It should be noted that the vertical sections of the 1 two species are very similar (compare fig.. 10 with fig. 1, pl. 25). However, the Mexican species normally has larger embryonic chambers and the coil of periembry- onic chambers is somewhat different from the one developed in M. (M.) panamensis. FAMILY MIOGYPSINIDAE . ,7 The embryonic apparatus: of M. (M.) mem'cana is Lisimilar ,to the one developed by. the type species M. (M.) burdigalensis (Gumbel). Bronnimann (1940, pl. 7, fig. 4) illustrated a specimen of the latter species Whose embryonic apparatus is entirely comparable to the Mexican species. Hanzawa (1947) has recently reinstated the generic name Heterosteginoides. Although the embryonic chambers lie in a subcentral position in both Miolepi- docyclina and Heterosteginoides, Hanzawa distinguished the two types by the development of the coil of peri- embryonic chambers. In Miolepidocyclina this coil is incomplete, whereas in Heterosteginoides the coil is complete. As there seems to be complete gradation between the two types, the necessity for two separate genera is questioned. It would appear that the degree of the development of the periembryonic coil is a specific, if not, an individual characteristic. Although M. (M .) panamensis and M. (M.) mericcma are related closely, for the present the two specific names are retained because it appears possible to dis- tinguish the two species by the features of the embry- onic apparatus. However, certain specimens (see pl. 25, fig. 12) do not differ markedly in this feature from M. (M.) panamensis. More thin sections of M. (M.) mext'cana are needed. REFERENCES CITED BARKER, R. W., minifera from S. W. Ecuador: pp. 277—281, pl. 16, 1 text fig. BERRY, W., Asterodiscocyclina, a new subgenus of Orth- ophmgmina: Ecologae geol. Helvetiae, vol. 21, pp. 405— 407, pl. 33. BR6NNIMANN, P., Uber die tertiaren Orbitoididen und die Miogypsiniden von Nordwest-Marokko: Schweizer. palaeont. Gesell. Abh., vol. 63, pp. 1—107, pls. 1—7, 37 text figs. COLE, W. 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Survey Bull. 29, pp. 1—339, 1 pl., 47 figs. COOKE, C. W., and Moss0M, S., Geology of Florida: Florida Geol. Survey 20th Ann. Rept., pp. 29—228, pls. 1—29. 1945. 1929. 37' 1943. COOKE, C. W., GARDNER, J., and WOODRING, W. P., Correlation of the Cenozoic, formations of the Atlantic and Gulf Coastal plain and the Caribbean region: Geol. Soc. America Bull. ., vol. 55, pp. 1713-1723, 1 chart. . 1937. CORYELL, H. N. and EMBICH, J. R. The Tranquilla shale (upper Eocene) of Panamaand its foraminiferal fauna: Jour. Paleontology, v01. 11, pp. 289—305, pls. 41-43, 1 text fig. 1919a. CUSHMAN, J. A., The larger fossil Foraminifera of the Panama Canal Zone: U. S. Nat. Mus. Bull. 19.}, pp. 89‘102, pls. 34—45. Fossil Foraminifera from the West Indies. Car- negie Inst. Washington Pub. 291, pp. 21— 7—1, pls. 1— 15, 8 text figs. The American species of Orthophragmina and Lepidocyclina. U. S. Geol. Survey Prof. Paper 125—D, pp 39—108, pls. 7—35, 3 text figs. DOUVILLE, H. Revision des Lépidocyclines: Soc. Geol. France Mém. 2, n. s., vol. 1, pp. 1- ~49, pls. 5, 6, 47 text figs. ELLISOR, A. C., Anahuac formation: Am. Assoc. Petroleum Geologists Bu11., vol. 28, pp. 1355—1375, 7 pls., 2 figs. GORTER, N. E., and VAN DER VLERK, I. M., Larger Foram- _ inifera from central Falcon, Venezuela: Leidsche Geol. Meded., vol. 4, pp. 94-122, pls. 11—17, 2 tables. GRAVELL, D. W., Tertiary larger Foraminifera of Vene- zuela: Smithsonian Misc. Coll., vol. 89, no. 11, pp. 1—44, pls. 1—6. GRAVELL, D. W., and HANNA, M. A., The Lepidocyclina texana horizon in the Heterostegina zone, upper Oligo~ cene of Texas Iand Louisiana: Jour. Paleontology, vol. 11, pp. 517—529, pls. 60—65, 1 fig. Subsurface Tertiary zones of correlation through Mississippi, Alabama and Florida: Am. Assoc. Petro- leum Geologists Bu11., vol. 22, pp. 984—1013, 7 pls., 5 figs. HANZAWA, S., Reinstatement of the genus Heterostegin- oides and the classification of the Miogypsinidae: Jour. Paleontology, vol. 21, pp. 260—263, pl. 41. HODSON, H., Foraminifera from Venezuela and Trinidad: Bull. Am. Paleontology, vol. 12, no. 47, pp. 1—46, pls. 1—8. JONES, S. M., Geology of Gatun Lake and vicinity, Panama: Geol. Soc. America Bu11., v01. 61, pp. 893— 922, 2 figs., 2 pls. LEMOINE, P., and DOUVILLfi, R., Sur 1e genre Lepidocyclina Gumbel: Soc. Géol. France Mém. 32, vol. 12, pp. 1—42, pls. 1—3. MACNEIL, F. S., Oligocene stratigraphy of southeastern United States: Am. Assoc. Petroleum Geologists Bu11., vol. 28, pp. 1313-1354, 1 fig. NUTTALL, W. L. F., Two species of Miogypsina from the ’ Oligocene of Mexico: Jour. Paleontology, vol. 7, pp. 175—177, pl. 24. RUTTEN, M. G., Larger Foraminifera of northern Santa Clara Province, Cuba: Jour. Paleontology, vol. 9,-pp. 527—545, pls. 59—62, 4 figs. THIADENS, A. A., Cretaceous and Tertiary Foraminifera from southern Santa Clara Province, Cuba: Jour. Paleontology, vol. 11, pp. 91—109, pls. 15—19, 3 text figs. VAN DE GEYN, W. A. E., and VAN DER VLERK, I. M., A monograph on the Orbitoididae occurring in the Ter- tiary of America: Leidsche Geol. Meded., vol. 7, pp. 221—272, 9 pls. 1919b. 1920. 1924. 1944. 1932. 1933. 1937. 1938. 1947. 1926. 1950. 1904. 1944. 1933. 1935. 1937. 1935. 38 EOCENE AND OLIGOCENE LARGER FORAMINIFERA IN THE CANAL ZONE 1923. VAUGHAN, T. W., Studies of the larger Tertiary Foram- inifera from tropical and subtropical America: Nat. Acad. Sci. Proc., vol. 9, pp. 253—257. American and European Tertiary larger Fora,- minifera: Geol. Soc. America Bull., vol. 35, pp. 785-822, pls. 30-36, 6 text figs. — The stratigraphic horizon of the beds containing Lepidocyclina chaperi on Haut Chagres, Panama: Nat. Acad. Sci. Proc., vol. 12, pp. 519—522. Larger Foraminifera of the genus Lepidocyclina related to Lepz‘docyclina mantelli: U. S. Nat. Mus. Proc., vol. 71, no. 2680, pp. 1~5, pls. 1—~4. New species of Operculina and Discocyclina from the Ocala limestone: Florida Geol. Survey 19th Ann. Rept., pp. 155—165, pls. 1, 2. Additional new species of Tertiary larger Foram- inifera from Jamaica: Jour. Paleontology, vol. 3, pp. 373—382, pls. 40, 41. ‘ Studies of American species of Foraminifera of the genus Lepz‘docyclina: Smithsonian Misc. Coll., vol. 89, no. 10, pp. 1—53, pls. 1—32. 1924. 1926. 1927. 1928. 1929. 1933. 1941. 1936. VAUGHAN, T. W., Helicolepidina nortom’, a new species of Foraminifera from a deep well in St. Landry Parish, Louisiana: Jour. Paleonotology; vol. 10, pp. 248—252, pls. 39, 40. ' American Paleocene and Eocene larger Foramini— fera: Geol. Soc. America Mom. 9, pp. 1-175, pls. 1—46, 11 figs. 1936. VAUGHAN, T. W., and COLE, W. S., New Tertiary Foram- inifera of genera Operattlina and Opercul'inoides from North America and the West Indies: U. S. Nat. Mus. Proc., vol. 83, no. 2996, pp. 487—496, pls. 35—38. Preliminary report on the Cretaceous and Ter- tiary larger Foraminifera of Trinidad, British West Indies: Geol. Soc. America Spec. Paper 30, pp. 1-137, pls. 1~46, 2 figs. 1927. WOODRING, W. P., Marine Eocene deposits on the east slope of the Venezuelan Andes: Am. Assoc. Petroleum Geologists Bull., vol. 11, pp. 992—996. 1949. WOODRING, W. P., and THOMPSON, T. F., Tertiary forma- tions of Panama Canal Zone and adjoining parts of Panama: Am. Assoc. Petroleum Geologists Bull., vol. 33, pp. 223—247, 2 figs. 1945. INDEX [Italic numbers indicate descriptions] A Acknowledgments ............................................................ 1 americana, Orbitolites ...................................... 2 americamua, Dtctyoconus ...................................................... 5,14 Amphisteginidae ............................................................. 14 antitlca. Heterosteaina, 6, 7,11, 18, pl. 5 Heterostcainoidea .......................................................... 35 Mioaypsma (Mfoaypsina) ...................................... 2, 7, 35, pls. 24, 25 Aunocudina ...................... 31, 32, 33 yamboamsis ............................................... 3 'aeorm‘cma ................................................ 31, pl. 27 kualeri ............. 32, 33, 35 Marianne/1.91.9 ........................................ 4, 5, 31, pls. 27, 28 minima .............................................. 2, 4, 32, pls. 26, 28 monticellensis. .......... 32, 34 rutteni ............................................. _ 33,35, pl. 26 aculpturata...--._..-.__‘ ........................... 33,34, 35,pl. 26 stewartl'... ...... 35 vermumi .................................................... 35 Asterocuclina), Discocudina .................................... 32 kuglcri, Discocycliua .................... 32 mariannmsis, Discocyctina __________________________ 31 rutteni, Discocyclina ________________________________ 32 sculpturata, Discocyclina 32 vermunti, Diacocycliua ............................ 1. 32,33 Asteriacitiea aeorgiana ................................. 3, 4 atterodiaca, Lepidocydina (Lepidocyclina) . . 17, pl. 17 Asterodiscocydma ............................... 32 stewam‘ ................................... 32 (Asterodiscocyclina) stewarti, Discocyclina ..................................... 32 B blumenthali, Pseudophravmlna (Proporocuclina) . _ . 35 Bohio formation, Foraminifera from ........ 6 bramletfei,Miogypsina ................ 1. 35,36 burdigale’nsis, Miawpsfna (Miolepidocyclina) .................................. 37 C Camerma .................................................................... 8,9,10 jacksonmcis ................................... 9 moodybranchemis .......................... 10 pom ................ 8 atriatoreticulata ...................... 5 8, pl. 3 Camerinldae ........................... 8 Caimito formation, Foraminifera from ..... 7 Calmito formation, fossil collecting localities. _ . ........... 6—7 canellei, Lepidocuclina (Lepidocwclina) ....... 1. 1, 2, 7, 18, pls. 16,17 uumayunmsis, lepidocudma .................................. 22 chaperi. Lepidocyclfina (N ephrolepidlna)...- 1, 2, 3, 4, 23, 24, 30, pls. 8—12, 20, 23 citrcmis, Paeudaphragmiua (Croporocyclina) 35, pl. 28 cubemn‘s, Eodictyocc'nus ......................... 14 Fabianfa ................ . 4, 5, 14,11]. 6 Lepidocyclina (N ephrolepidina) fragilis. . .. 27 Pseudorbftoli'na ..................... 14 curucm'ca, Lepidocydina. _ cuahmanl, Miowpsina. . Cymbaloporidae ........................ dartomi, Lepidocyclfna (N ephrolcpidina) A. davidemis, Nummulites __________________ 2 decorum, Lepidocyclina (N cphrolepidina) _ 3 Dicty/oconus americanus. 5, 14 puilboreauemia.... 5 Discocyclina ________ 3, 33 (Aaferocuclina) ___________ 32 kuglerl ................. 32 mariannensia. . 31 111mm... ................. 32 sculpturata.. ................. 32 ve’rmunti .......... _ 32,33 (Asterodiacocyclina) stewartz. 32 (Diacocyclina) ............ 32 minima .................. 32, 33, 34 (Diacocucli'nu) minima, Diacocvdma" .......................... 32, 33, 34 Discooyclinidae .............................................. 31 dim, Operculinoides. 6 duplicuta, LepidocI/clma. ..................................... 2, 17 Multfcyclina .............................................................. 2 E ecuadormm, Miolepidocuclina ............................... 36 Eodidyoconua cubmsio .................................. 14 Eulepfdina .............................. _.. 6, 7, 30 (Eulcpidina) favoaa, Itpidocuclina ..... 6, 30. pl. 22 Lepidocyclina ......................... 6 undosa, Lepidocyclina ............................................. 7, 18, 30, pl. 22 F Fubiania __________________________________ 5, 14 cubemis ............................... 4, 5,14, pl. 6 falconenais, Leptdocudina (Lepidocwcliua).. ...... 17 favosa, Lepidocyclma (Eulepfdma).. 6.30, pl. 22 flintmsis, Orthophraamina ................... 35 Pseudophraamina (Proparocyclina)_, 4 35. pl. 28 fion‘damz, Gunteria... ............. 14 flaridensia, Nummuliteo. 9 Opercidinoides ...................... 4, 9 Foraminifera, from Bohio formation .................. 6 from Caimito formation __________________________ 7 from Gatuncillo formation .................... 4 from Trinidad Island _______________ 5 formrti, Lepidocyclina (Lepidocyclina) ________ 21 pl. 18 Fossil collecting localities, Bohio formation. 6 Caimito formation ............................ 6-7 Gatuncillo formation ......................... 4 Trinidad Island ................................ 5 mail“ cubensis, Lepidacyclina (Nephrolepfdina). ._ _._ 23,27 Lepidocyclma (Nephroleptdma) ............................ 23 25 27 30 pls 9 23 G vamboaemis, Asterocuclma .................................................... 3 Gatuncillo formation, Foraminifera from___. 4 Gatuncillo formation, fossil collecting localities“ 4 georuiana, Asteriacities .................................. 3, 4 Aalerocuclina ...... t. 3, 4, 31, pl 27 Orthophraquna. ________ 3i aigaa, Lepidocyclina ....... 6, 30, pl. 22 glabra, Heterostegina oculana ................................ 3,13 pranosa, Lepidocuclina (Nephrolepidina) semmm ..... , .......... 23, 27 guber'nacula, Lepidocyclfna (Pliolepidina) ...... 4, 15, pls. 8, 9, 12, 20,23 Gunteria flaridana _______________________ 14 E haddinalonensis, Lepidoc-yclina (Nephrolepidma) ............................... 23, 27 hawkinsl, Miogypsina _______________________ hayesi, Orthophragmma .............. Helicolepidina _________ nortonf..__ apiralic... Helicolepidinae. .......................................................... 30 Helicosteaina .......................... 14 aoldadensia ............................................................ 4, 14, pl. 6 Heterosteama_._._.....1,...,...,................__._...‘ ................ 6,7,11,17,18 antillea... 6,7,11,18,pl.5 israelskyt. . ................................................ 7,12,18, pls. 1, 4-6 ocalana ................................................................ 4, 13,111. 4 ocalana glabra ....................... panamemia .......... , ................................................. 7, 14,111 5 texana ............................................ 12 Heteromginaides ...................... . 37 antillea ........................................... 35 panamemis .......................................... ,. .................. 2, 35, 36’ 1—1 Isolepidina pustulosa ......................................................... 16 israelskyi, Heterosteaina ........................................... 7, 12,18,pls. 1,4-6 jacksommis, Camerina ........................................................ 9 Operculinoidea ....... 4, 5, 9, pls. 1,3 jamaicmaia, Yabermcllu .................................................. 4, 5, 8, p1.6 K kuolerf, Asterocyclma ....................................................... 32, 33, 35 Diacocyclina (Asterocyclina) ........................... 32 Operculinoides ...................................................... 5, 9, 11, pl. 3 39 4O INDEX L M lehneri, Lepidocyclina (Nephrolepidina) ________________________________________ 29 macdonala‘i, Lezn'docyclina (Lepidocyclma) ..................................... 16 Lepidacyclina ....................... 2, 3, 15, 17, 18, 21 (Plialepidina) ........................................ 2, 4, 5, 16, pls. 7, 8, 14, 20 canellei yurnagunensis ..................................................... 22 mantelli, Lepz‘docyclina (Lepidocz/clma) ................................... 6,21, pl. 18 curasavica ,,,,,,,,,,,,,,,,,,,,,,, mariannenais, Asterocyclina ........................................ 4, 5, 31, pls. 27, 28 duplicala.. Discocyclina (Asterocyclinu). 31 Orthophragmina ______________________________________________ 31 papillata, Orthophragmina ................................................. 31 meinzm‘, Lepidocyclina (Lepidocyclina).. _____________ 16 mexicana, Miogypsina (Miolepidocyclina),. _______________ 36, 37 minima, Asterocyclina ......................... 2, 4, 32, pls. 26, 28 Discocyclina (Discocyclina) ............................................. 32, 33, 34 falclmemis ............................................................ 17 Orthophnzgmz’na _________________________________________________________ 2, 32,33 161M. . _. 21, pl. 18 Miogypsind ______ - 6, 7 . V@da‘oMldi.‘___._,__.........,.1._.' __________________________________ 2,16 bramlettei.. .. 35,36 mantelli _________________________________________________________ 6, 21, p]. 18 cushmani 2, 35 , memzeri .............................................................. 16 hawkinsi .................................................................. 36 mirafloremis ................................................. 2, 20, 21, pl. 18 (Miogypsma) ............................. 35 mgmtgomeriensis. 4, 20, pls. 15, 20, 23 antillea. . . . 2, 7, 36, pls. 24, 25 novitase'nsis ___________________________________________________________ 16 (Miolepidocyclina) _____________________________________________________ 36, 37 pancanalis ......................................................... 18, 19, 20 burdigalensis ......................................................... 37 parvula . n ._ 6, 7, 18, 20, pl. 15 mezicama ..................................................... ___. 36,37 submulim’i ______ 23, 27, pl. 23 panammsis _______________________________________________ 2, 6, 7, 30, 56‘, pl. 25 supea..._ . 6, 7, 21, pl. 18 (Miogz/psina) antillea, Miogypsinm _, 2, 7,'35,pls. 24, 25 191mm. _ ............................................................ 17 M iogypsinid 30 ............................................................... 35 tschoppi...._._1.-...-.___.__.-._..............,._.,_._._.________ 23, 27, 1.718 Miolepidocyclinaecuadorensis......______...._.__.....................-.. 36 wayltmdmughani ________ 2, 6, 7, 20, pl. 18 (MiolEpidoci/clina) burdiaale’nsis, Aliagypsina. , yumagunensis... __ .. 6, 7, 18, 22, pls. 15, 17, 20 mezicanu, Aliogypsina. .......... yumagunensis moraanopsis. ................ 6, 7, 23, pls. 15, 23 Miogypsz’na ____________________ (Nephroleptdina) chapzri ..................... 1, 2, 3, 4, 23, 24, 30, pls. 8-12, 20, 23 panamensz‘s, Mioaypsina ..................................... 2, 6, 7, 30, 36, pl. 25 dartom' ___________________________________________________ _.._ 7, 27', pl. 19 miraflorensis, Lepidocyclina (Lepidocyclina) ............................ 2, 20, 21, pl. 18 decorum. 3 mirandana, Lepidowclina (Polylepidina) . _ ........ ____ 17 frugilia ........................................... 23, 25, 27, 30, 1315.9, 23 Pseudaphragmz'na (Proporocyclina) ............. __ 35, pl. 28 [moms cubmsis ........ A ................................ 23, 27 montgomeriensis, Lepidocyclina (Lepidocyclina) ______________ 4, 20, pls. 15, 20, 23 haddingtamnsis ........................................................ 23,27 moadybranchensis, Camerma ___________________________________________________ 10 lehmri ................................................................ 29 Operculinoidea ..................................................... 4, 9, 10, pl. 1 sanfemandensis ............. .___ 24, 25,27 montz’cellenais, Asterocyclinm”. ............. 32, 34 sanfernandemis tullahasscensis ........................... 24, 25, 27, pls. 9, 10 morganopsis, Lepidocyclma (Lepz'dacyclina) yumagumnsis _________ 6, 7, 23, pls. 15, 23 3271111168! ................................................. 23, 25, 26, 27, pl. 12 A/[ulticl/clina dwmlicuta ......................................................... 2 semmesi granosa. ................. 23,27 _ tantoyucemis ______________ 23, 26, 27 1‘“ tempanlL" . 18' 28’ 29, p]_ 19 Nephrolepidina -------------------------------------------------------- 201 211 231 27 mummy,- ______________________________________________________ 7, 28, pl. 19 ( Nephrolepidi'na) chaperi, Lepidocyclina. .. . 1, 2, 3, 4, 23, 24, 30, pls. 8—12, 20, 23 “Wham ____________________________________________ 2, 6, 7, 99, p15, 18, 20, 21 dartoni,Lepid061/clina ---------------------------------------------- — 7,137,111. 19 decorum, Lepidocyclina ____________________________________________________ 3 mm” pseudocari’natu ________________________ fragilia, Lepidocyclina ......... pancanalis ........................ 23, 25, 27,30, pls. 9, 23 macdonaldi ____________ . 2, 4, 5, 16, pls. 7, 8, 14, 20 pustulosa ___________ 2, 4, 5, 16‘, pls. 13-15, 20, 23 pustulosa tobleri ........................................ 2, 4, 5, 17, pls. 13-15 subglobosu ...................................................... tobleri ........ 17 (Polylepidina) mimnda-na _________________________________________________ 17 proteifarmis __________________ 17 17 submulinii _________________________________________________________ 23, 27, pl. 23 undosa ................................................................... 6, 30 vaughani ......................................................... 2. 7, 20, 21 (Lepidocyclina) asterodisca. Lepidocydina ________________________________ 7, 17, pl. 17 falconensis, Lepidocydina ____________________________________ 17 forresti, Lepidocyclina" ....................... 21, pl. 18 mantelli, Lepidocyclina__ . 6,21 pl. 18 meinzeri, Lepz‘docyclina ____________________________________________________ 16 miraflorensis, Lepidocyclina ______________________________________ 2, 20, 21, pl. 18 montgomeriensis, Lepidocyclinau 4, 20, pls. 15, 20, 23 macdzmaldi, Lepidocyclina _________________________ ,_ 16 novitaaensis, Lepia'ocyclina _________________________ 16 pancanalia, Lepidocyclina _____________ parvula, Lepidocyclina __________________________________________ 6, 7, 18, 20 pl. 15 subraulinli, Lepidocyclina ...... 27 supera, Lepidocyclina .............................................. 6, 7, 21, pl. 18 tezana, Lepidocyclina _____________________________________________________ 17 tschoppi, Lepidocz/clina ____________ 23,27, p].8 waylandvaugha’ni, Lepidocyclina. _ ........ 2, 6, 7, 20, pl. 18 yumagunensia, Lepidacyclina __________ _ 2 6, 7, 18, 22, pls. 15, 17,20 yumagunmsia moraanopsis, Lepidocyclz‘na ...................... 6, 7,23, pls. 15,23 Lepidocyclinae ............................................................... 16 Lituolidae ____________________________________________________________________ 8 haddingtanernsis, Lepidocz/clina. _ 23, 27 lehnen’, Lepidocuclina ......... __,. 29 sanfemundensis, Lepidocyclina ......................................... 24, 25, 27 tallahasseensis, Lepidocyclina ____________________________ 24, 25, 27, pls. 9, 10 semmeai, Lepidocyclz'na ________ . 23, 25, 26, 27, pl. 12 granosa, Lepidocyclina ................................................ 23, 27 tantayucensis Lepidocyclina ............................................ 23, 26, 27 tempanii, Lepidocyclina ......................................... 18, 28, 29, pl. 19 tournauen‘, Lepidocyclina ............................................ 7, 28, pl. 19 vaughani, Lepidocyclinm. . - 2, 6, 7, 29, pls. 18, 20, 21 verbeelcz', Lepidocyclina ..................................................... 30 nortam‘, Helicolepz’dina .................................................... 30, pl. 24 nom'tasensis, Lepidocyclina (Lepz'docyclina). _ 16 Nummulites panamensis. ______________ .. 2, 10 daoidensis _______________ - 2 floridensis ................................................................ 9 striutoreticulatus ........................................................... 8 O oculana glabra, Heterostegina _____________________________________ Heterostegz'na ________ Operculz‘na _______ pseudocarinata Lepidocyclina ............................................. 16 ocalanus, Operculinoides _______________ 2, 4, 10, pl. 2 Operculina .................................... oculana _________________________________ trinitatensis _______________________________________________________________ vaughani ................................................................. .. 11 Operculinoides. . 9, 10, 18 dius ...................................................................... 6 flaridensz’s ................................................................. 4, 9 jacksonensis. 4, 5, 9, pls. 1, 3 kugleri ............................. 5, 9, 11, pl. 3 moodybranchensis" ________________ 4, 9, 10, pl. 1 oculanus ........................................................... 2, 4, 10, pl. 2 panamnsis ....................................................... 2, 7, 10, pl. 2 trinitatmxis" 5, 11, pls 2, 3 vauqham'... ________ . 4,11, pl. 2 vicksbumenszs.._._._.....-..............__ .7 _____________________________ 11 ' I 41 INDEX Opercullnoides—Continued aculpturata, Asterocyclina .......................................... 33, 34, 35, pl. 26 wileati... 10 Discocyclina (Asterocyclina) __________ 32 0rbltoididae... 15 Orthophmgmina ___________________________________________________________ 32 Orbitolites americana .......................................................... 2 semmcsi aranosa, Lepidocuclina (Nephrolepidina) __________________________ 23, 27 Orthophraamina ............................................................... 2 . Lepidocyclina (Nephrolepidina) ............................... 23, 25, 26, 27, pl. 12 flimemis... 35 soldademis, Helicosteaina ______________ georgitma- . 31 spiralis, Helicolepidina ____________________________________________ 4, 27, 30, pls. 20, 24 hayesi ___________________________________________________________ , ......... 16, 17 atewarti, Asterocyclina ___________________________________________ mariannensis ................ Asterodiscocyclina ___________________ papillata __________________ Discocyclina (Asterodiscocuclina) minima ______ P pancanalis, Lepidocyclina .......................................... 6, pls. 16, 17 (Lepidocyclina) ..................... 18, 19, 20 panamensis, Heterostegina ............... . 7, 14, pl. 5 Heterosteginoides ....................................................... 2, 35, 36 Lepidocyclina ............................................................. 2, 17 Miogypsina (Miolepidocz/clina)._ . 2, 6, 7, 30, 36', pl. 25 Nummulites .............................................................. 2, 10 Operculinaides ...................................................... 2, 7,10, pl. 2 papillata, 071haphragmina marianwemis. 31 parvula, Lepidocyclina (Lepidocyclina) _ _ ________________ "6, 7, 18, 20,131. 15 persimilis, Lepidocyclma .................. 27 perundosa, Lepidocyclina ...................................................... 23, 27 petri, Camerina ............................................................... 8 pustulosa toblen‘, Lepidocyclinu (Pliolepidina) _ 2, 4, 5,17,p1s. 13~15 Pliolepidina. ................. 15 tobleri ............................ ...- ________ 17 (Pliolepidina) gubernacula, Lepidocyclina ...................... 4, 15, pls. 8, 9, 12, 20, 23 macdonaldi, Lepidocyclina ________________________________ 2, 4, 5, 16, pls. 7, 8, 14, 20 pustulosa, Lepidocyclina ............ __ 2, 4, 5, 16, pls. 13—15, 20, 23 tobleri, Lepidocyclina _____________________________________ 2, 4, 5, 17, pls. 13—15 aubglobosa, Lepidocz/clina _________________________________________ 16 tobleri, Lepidocyclma ................ 17 (Polylepidina) miranduna, Lepidocycliua. _ 17 proteiformis, Lapidocyclina .......... 17 zuliana, Lepidocyclina __________________ 17 (Proporocyclina) blumenthali, Pseudophrag mind ______________________________ _ 35 citrensis, Pseudophragmina ............... _ 35, pl. 28 flintemis, Pseudophragmina __________ 4, 35, pl. 28 mirandana, Pseudophragminaun 35, pl. 28 Pseudophragmina. _______________________________________________________ 35 tobleri, Pseudophragmina __________________________________________________ 35 proteiformis, Lepidacyctina (Polylepidina) _ 17 pseudocarz'nata, Lepidocyclma ocalana _________________________________________ 16 Pseudophragmina _____________________________________________________________ 35 (Proporocyclina) _________________________________________________________ 35 blumenthali .......................................................... 35 citre’hais. - . 35, pl. 28 flintmsis ........................................................ 4. 85, pl. 28 , mimndana ________________________________________________________ 35, pl. 28 loblen‘. _ _ ____ 35 Pseudorbitmma cube'nsis ..................... 14 puilboreauensis, Dictyoconus ________________ 5 pustulosa, Isolepidina ________________________________________________________ 16 Lepidocyclina (Plioepidina) ........................... 2, 4, 5, 16', pls. 13—15, 20, 32 R S sanfernandensis, Lepidocyclina (Nephrolepidina) ____________________________ 24, 25, 27 lallahasseemz‘s, Lepidocyclz‘na (Nephrolepidinu) ________________ 24, 25, 27, pls. 9, 10 striatoreticulata, Camerina. . . _ _ _ ._ Nummulitics .................................................. subalobosa, Lepidocyclina (Pliolepidina) ............................ ‘ subraulmil, Lepidocyclina ............. 23,27, pl. 23 Leptdacyclinu (Lepidocz/clina) ________________________________ 27 supera, Lepidocyclina (Lepidocyclina) _ _________________________________ 6, 7, 21, pl, 18 ' g/ x‘” '4” , fl 5*“ «w - «’ 4M Ell-35!!!! QEIEIIEEIIL‘MHII! 1!!!!“ I 1 l I! E! E tallahusseensia, Lepidocyclina (Nephrolepidinu) sunfernandehsis. . _. 24, 25, 27, pls. 9,10 tantoyucensis, Lepidocyclina (Nephrolepidina) ............................... 23, 26, 27 tempam'i, Lepidocyclma (Nephrolepidina) _____________________________ 18, 28, 29, pl. 19 Tertiary formations of area (chart) ............................................ 2 lemma, Heterostegina _______________________________________ 12 Lepidocyclina (Lepidocycli'mz) _ 17 tobleri, Lepidocyclina (Plialepidina) .......................................... ~ .. 17 Lepidocycling (Pliolepidina) pustulosa ________________________ 2, 4, 5, 17, pls. 13—15 Pliolepidina ________________________ Pseudophraumina (Proporocyclinu) __ loumauen, Lepidocyclina (Nephrolepidina) trelawniensis, Yaberinella ..................................................... trinitatemls, Operculina ....................................................... 11 Operculinoides ________________ 5, 11, pls. 2, 3 Trinidad Island, Foraminifera from ___________________________________________ 5 fossil collecting localities __________________________________________________ 5 tschoppi, Lepidocyclina (Lepidocyclina) .................................. 23, 27, pl. 8 U undosa, Lepidocyclina _________________________________________________________ 6, 30 Lepidocyclina (Eulepidina) _ _ .. . _ 7, 18, 30, pl. 22 V Vaughan, T. W., quoted ................................................ 8, 20, 30, 33 and Cole, W. 8., quoted _______________________________________________ 11, 18,26 vaugham', Lepidocycliml .................. 2, 7, 20, 21 Lepidocyclinu (Nephrolepidma)__ -._ 2, 6, 7, £9, pls. 18, 20, 21 Operculina ______________________ 11 Operculinoides ______________________________________________________ 4, 11, pl. 2 verbeeki, Lepidacyclina (Nephrolepidina) ....................................... 30 vermumi, Asterocyclina ................. 35 Discocyclina (Aslerocyclina) _______________________________________________ 32, 33 vicksburgmsis, Operculiuoides _________________________________________________ 11 W waylundvaughani, Lepidocycli'na (Lepidocyclina) ..................... 2, 6, 7, 20, pl. 18 wilcozi, Operculinoides .......................................................... 10 Y Yaberinella ................................................................... 5, 7 jamaicemis ......................................................... 4, 5, 8, pl. 6 trelawmensis“__..______:' _________________________________________________ 5, 8 yur'nagunmsis. Lepz'docyclina canelli. . _-. 22 Lepidocyclina (Lepidocyclina) __________________________ 6, 7, 18, 22, pls. 15, 17, 20 morganopsis, Lepidocyclina (Lepidocyclina) ___________________ 6, 7, 23, pls. 15, 23 zuliana, Lepz'docyclina (Palylepidina) __________________________________________ l7 PLATES 1—28 FIGURES 1—9, 20—21. 1— 4. . Median sections, X 20, of 2 specimens; locality 108. U.S.N.M. 560931. . External views, X 15, of 6 specimens illustrating the surface ornamentation; locality 108. U.S.N.M. 560932. . Transverse section, X 20, showing the axial plugs and the surface beading; locality 149. U.S.N.M. 560937. . Median section, X 20; locality 149. U..S N. M. 560938. . Operculinoides moodybranchensis (Gravell and Hanna) (p. 10). . External view, X 15; locality 108. U.S.N.M. 560933. . Part of the transverse section, figure 13, X 40, illustrating marginal cord and apertures; locality 108. . PLATE 1 Operculinoides jacksonensis (Gravell and Hanna), (p. 9). Transverse sections, X 20, of 4 specimens; locality 108. U.S.N.M. 560930. U.S.N.M. 560934. . Transverse section, X 20; locality 108. U.S.N.M. ‘560935. . Transverse section, X 12.5; locality 108. U.S.N.M. 560934. ' . Median sections, X 12.5, showing individual differences; locality 108. U.S.N.M. 560936. . Heterostegina israelskyi Gravell and Hanna (p. 12). Part of an equatorial section, X 40, showing the embryonic chambers and the single operculine chamber; locality 110. U.S.N.M. 560939. GEOLOGICAL SURVEY - PROFESSIONAL PAPER 244 PLATE 1 9a EOCENE OPERCULINOIDES AND OLIGOCENE HETEROSTEGINA FIGURES 1—4. la—ld. PLATE 2 Operculinoides panamensis (Cushman) (p. 10). External view, X 15, of 4 specimens; locality 55. U.S.N.M. 560940. 2. Transverse section, X 20, showing the large umbonal plug and nearly parallel sides of the test; locality 55. U.S.N.M. 560941. 3, 4. Median sections, X 20; locality 55. U.S.N.M. 560942. 5-11. Operculinoides ocalanus (Cushman) (p. 10). 5. Median section, X 20; locality 125. U.S.N.M. 560943. 6. Median section, X 12.5; station 131a. U.S.N.M. 560944. 7. Transverse section, X 20, of a specimen with a large umbo; locality 125. U.S.N.M. 560945. 8. Transverse section, X 20, of a specimen with a low umbo; locality 131a. U.S.N.M. 560946. 9. External view, X 10, of a specimen with a low umbo and strongly raised sutures; locality 125. U.S.N.M. 560947. 10. External view, X 10, of a specimen with a small, strong umbo and slightly raised sutures; locality 132. U.S.N.M. 560948. 11. External view, X 10, of a specimen with raised sutures and supplemental beading along the sutures; locality 140. U.S.N.M. 560949. ' 12—16. Operculinoides vaugham' (Cushman) (p. 11). 12. External view, X 10, of a megalospheric individual; locality 140. U.S.N.M. 560950. 13. External View, X 10, of a microspheric individual; locality 140. U.S.N.M. 560951. 14. Transverse section, X 12.5, of a microspheric individual; locality 140. U.S.N.M. 560952. 15, 16. Median sections, X 12.5; locality 1.40. U.S.N.M. 560953. 17—19. Operculinoides trinitatensis (Nuttall) (p. 11). 17. Median section, X 20, showing the heavy revolving wall; locality 149b, U.S.N.M. 560954. 18, 19. External views, X 15, showing surface ornamentation; locality 149b. U.S.N.M. 560955. GEOLOGICAL SURVEY { PROFESSIONAL PAPER 244 PLATE 2 EOCENE AND OLIGOCENE OPERCULINOIDES FIGURES 1—7. 1—4. 5a—5d. 6—7. . Median section, X 12.5, of a specimen similar to the one illustrated as figure 16; locality 140. U.S.N.M. PLATE 3 Operculinoides kuglem' Vaughan and Cole (p. 9). Median sections, X 20; locality 149b. U.S.N.M. 560956. External View, X 15, of 4 specimens illustrating surface ornamentation; locality 149b. U.S.N.M. Transverse sections, X 40; locality 149b. U.S.N.M. 560958. Operculinoides jacksonensis (Gravel! and Hanna) (p. 9). 560957. Transverse section, X 40, showing the contrast between this species and 0. kugleri; locality 149b. U.S.N.M. 560959. . Operculinoides trinitatensis (Nuttall) (p. 11). . Transverse sections, X 20; locality 149b. U.S.N.M. 560960. . Median section, X 20, showing thick revolving wall and oblique chamber walls; locality 149b. U.S.N.M. 560961. . Camerina striatoreliculata (L. Rutten) (p. 8). ' - . Transverse section, X 12.5; locality 140. U.S.N.M. 560962. . Transverse section, X 20, of a small individual; locality 149b. U.S.N.M. 560963. . Transverse section, X 12.5, of a normal sized specimen; locality 149b. U.S.N.M. 560964. . External View, X 5, of an eroded specimen which does not show surface ornamentation; locality 125. U.S.N.M. 560965. . External view, X 5, of two slightly eroded specimens with the ornamentation largely preserved; locality 140. U.S.N.M. 560966. 560967. Median section, X 12.5, of a specimen similar to the one illustrated as figure 17; locality 140. U.S.N.M. 560968. . Median section, X 12.5; locality 149b. U.S.N.M. 560969. PROFESSIONAL PAPER 244- PLATE 3 GEOLOGICAL SURVEY EOCENE AND OLIGOCENE OPERCULINOIDES AND CAMERINA. FIGURE 1. 2—18. 2. con 535.114; co PLATE 4 Heterostegina ismelskyi Gravell and Hanna (p. 12.) External View, X 10, of the only specimen of this species recovered from this sample; locality 55. U.S.N.M. 560970. Heterostegina ocalana Cushman (p. 13). External View, X 10, of a virtual tOpotype; from Ocala limestone, Cummer Lumber Company Phosphate Pit no. 6,1 mile south of Newberry, Alachua County Fla. U. S. N. M. 560971. . External view, X 10, of two specimens from Panama showing their similarity to the Floridian specimen; locality 140. U.SN.M . 560972. . Transverse section, X 20; locality 22a. U.S.N.M. 560973. Median section, X 20; locality 22a. U. S. N M. 560974. Part of a median section, X 20, which has 3 operculine chambers following the embryonic chambers; from Ocala limestone, same locality as fig. 2. U. S. N. M. 560975. . Median section, X 20; locality 140 U S. N.M . 560976. . Median section, X 20, of a specimen which has 7 operculine chambers following the embryonic chambers; from Ocala limestone, Red Bluff, Ga. U. S. N. M 560977. . Median section, X 20, with 10 operculine chambers; locality 125. U S. N. M. 560978. . Part of a median section, X 20, with 6 operculine chambers, from Ocala limestone, same locality as fig. 2. U.S.N.M. 11. 12. 13. 14. 15. 16. 17. 18. 560979. Median section, X 20; locality 125. U.S.N.M. 560980. Median section, X 20, with 2 operculine chambers; locality 140. U.S.N.M. 560981. Transverse section, X 20; locality 125. U. S. N. M. 560982. ' Median section, X 20, with 7 operculine chambers; from Ocala limestone, Red Bluff, Ga. U.S.N.M. 560983. Transverse section, X 20; from Ocala limestone, Red Bluff, Ga. U. S. N. M. 560984. Median section, X 20, of a microspheric specimen “ith 15 operculine chambers; from Ocala limestone Red Blufl“, Ga. U. S. N. M. 560985. Median section, X 20, of a megalospheric specimen with 8 operculine chambers, locality 22a. U.S.N.M. 560986. Transverse section, X 20; locality 140. U. S. N. M. 560987. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 4 EOCENE AND OLIGOCENE HETEROSTEGINA FIGURES 1—11. PLATE 5 Heterostegina antillea Cushman (p. 11). Median section, X 12.5; locality 43. U.S.N.M. 560988. . Median section, X 20; locality 38. U.S.N.M. 560989. Transverse section, X 20; locality 38. U.S.N.M. 560990. Transverse section, X 20, not centered; locality 39. U.S.N.M. 560991. Transverse section, X 20, of a well—developed individual with heavy axial plugs; locality 43. U.S.N.M. 560992. Transverse section, X 20; locality 37. U.S.N.M. 560993. Median section, X 20, not absolutely in the median plane; locality 45. U.S.N.M. 560994. . Median section, X 20; locality 39. U.S.N.M. 560995. . Median section, X 20; locality 37. U.S.N.M. 560996. Median section, X 20, showing the large, relatively thick-walled embryonic chambers and the single, large operculine chamber; locality 45. U.S.N.M. 560997. . Median section, X 20; locality 38. U.S.N.M. 560998. . Heterostegina israelskyi Gravell and Hanna (p. 12). . Median section, X 12.5, of a probable microspheric specimen; locality 110. U.S.N.M. 560999. Portion of a median section, X 20, showing the embryonic chambers; locality 110. U.S.N.M. 561000. . Transverse section, X 20, of a megalospheric individual; locality 110. U.S.N.M. 561001. . Heterostegina panamensis Gravell (p. 15). Median section, X 20; locality 11a. U.S.N.M. 561002. Transverse section, X 20; locality 11a. U.S.N.M. 561003. . Median section, X 20; locality 55. U.S.N.M. 561004. . Transverse section, X 20; locality 55. U.S.N.M. 561005. . External view, X 15; locality 55. U.S.N.M. 561006. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 5 {wilhza ”WNW, ,- 1;"? gaum3 a f 2%: , ' K, .j, , ’e \. .. , OLIGOCENE HETEROSTEGINA FIGURES 1—8. . Transverse section, X 20; locality 131. 1 2 3. Several random transverse sections, X 20; locality 131. 4, 5. 6. Part of a median section, X 20; locality 131. 7. Median section, X 12.5, of a topotype specimen introduced for comparison with the Panamanian specimens; from . External View, X 15, of the dorsal aspect; locality 140. . Part of an axial section, X 40; locality 22a. . Heterostegina ismelskyi Gravell and Hanna (p. 12). 7. Median section, X 20; locality 110. U.S.N.M. PLATE 6 Yabem'nella jamaicensis Vaughan (p. 8). U.S.N.M. 561007. . Transverse section, X 20, showing in the embryonic chamber a curved partition which may indicate that the embryonic U.S.N.M. 561008. U.S.N.M. U.S.N.M. 561010. U.S.N.M. 561011. apparatus is bilocular; locality 131. 561009. Transverse sections, X 20; locality 131. yellow limestone, locality J505M., Phantillands parochial road, 1.8 miles from the main road, Jamaica. U.S.N.M. 561012. Transverse section, X 12.5, of a topotype specimen introduced for comparison with the Panamian specimens;from same locality as fig. 7. U.S.N.M. 561013. . Helicostegina soldadensis Grimsdale (p. 14). . Median sections, X 40; locality 22a. U.S.N.M. U.S.N.M. 561014. 561015. 561016. External View, X 15, of the ventral region; locality 149b. U.S.N.M. U.S.N.M. 561019. Transverse section, X 40; locality 22a. . Fabiam’a cubensis (Cushman and Bermudez) (p. 14). L Axial section, X 20; locality 140. U.S.N.M. 561017. 561018. U.S.N.M. 561020. 1 Several random transverse sections, X 12.5; locality 110. U.S.N.M. 561021. GEOLOGICAL SURVEY PROFESSIONAL PAPER 24-4 PLATE 6 EOCENE YABERINELIA, HELICOSTEGINA, AND FABIANIA, AND OLIGOCENE HETEROSTEGINA FIGURES 1—19. 1. 2—16. PLATE 7 Lepidocyclina (Pliolepidina) macdonaldi Cushman (p. 16). Vertical section, X 12.5, of a microspheric individual; locality 149b, U.S.N.M. 561022. Vertical sections of megalospheric individuals, showing variation. 20; locality 132. U.S.N.M. 561023. 20; locality 15. U.S.N.M. 561024. 20; locality 125. U.S.N.M. 561025. 20; locality 125. U.S.N.M. 561026. 20; locality 131. U.S.N.M. 561027. 20; locality 140. U.S.N.M. 561028. 12.5; locality 125. U.S.N.M. 561029. 12.5; locality 140. U.S.N.M. 561030. 12.5; locality 150. U.S.N.M. 561031. 20; locality 140. U.S.N.M. 561032. 20; locality 140. U.S.N.M. 561033. 20; locality 149b. U.S.N.M. 561034. 12.5; locality 125. U.S.N.M. 561035. 12.5; locality 149b. U.S.N.M. 561036. 20; locality 125. U.S.N.M. 561037. External view, X 10, of a megalospheric specimen, showing raised pustules; locality 125. U.S.N.M. 561038. Equatorial section, X 12.5, of a megalospheric individual; locality 132. U.S.N.M. 561039. XXXXXXXXXXXXXXX . Equatorial section, X 12.5, of a megalospheric individual; locality 149b. ‘U.S.N.M. 561040. PROFESSIONAL PAPI'ER 24-4 PLATE 7 GEOLOGICAL SURVEY m M. ‘5 I . r n. l | I. . A. I I l 9. .2. .u‘ hi. I f.) :42. v we) a! Q.- «.4: II EOCENE LEPI DOC YCLI NA FIGURus 1—4. » 9—14. 9. 10. 11. 12, 13. 14. PLATE 8 Lepidocyclina (Pliolepidina) macdonaldi (Iushman (p. 16’). Equatorial section, >< 12.5;locality 125. U.S.N.M. 561041. 1 2. Equatorial section, X 20; locality 132. U.S.N.M. 561042. 3. 4. 5—8. 5. Vertical section, X 20; locality 125. U.S.N.M. 561045. 6. Vertical section, X 40; locality 22a. U.S.N.M. 561046. 7. 8. Equatorial section, X 20; locality 22a. This type of specimen has been named by Thiadens (1937, p. 103) L. (L.) Equatorial section, X 20; locality 125. U.S.N.M. 561043. Equatorial section, X 12.5; locality 140. U.S.N.M. 561044. Lepidocyclina (Nephrolepidina) chaperi Lemoine and R. Douvillé (p. 23). Vertical section, X 20; locality 22a. Il.S.N.M. 561047. tschoppi. U.S.N.M. 561048. Lepidocyclina (Pliolepidina) gubernacula Cole, n. sp. (p. 15). Vertical section, X 20; locality 22a. U.S.N.M. 561049. Vertical section, X 20, of a small specimen; locality 22a. U.S.l\'.M. 561050. Equatorial section, X 20, of a small specimen showing in the peripheral zone radially elongate equatorial chambers; locality 22a. U.S.N.M. 561051. Equatorial sections, X 12.5, of two paratypes showing embryonic chambers and the rhombic equatorial chambers; locality 23. U.S.N.M. 561052. Vertical section, X 12.5, of a paratype showing the great expansion of the equatorial layer at the periphery of the test and the open lateral chambers with thin floors and roofs; locality 23. U.S.N.M. 561053. PROFESSIONAL PAPER 24-4- PLATE 8 GEOLOGICAL SiURV EY , . IS. or 5. re. a A 1354‘ 3.1.». .u. 005‘ “3(‘5 / d . .fimmm 514.3,»?! w \ EOCENE LEPIDOCYCLINA FIGURES 1, 2. PLATE 9 Lepidocyclz‘na (Pliolepidina) gubernacula Cole,.n. sp. (p. 15). 1. Vertical section, X 12.5, of a compressed specimen; locality 23. U.S.N.M. 561054. 2. 3—19. 3. @UHA q 14—17. 18. 19. Vertical section, X 12.5, of an inflated paratype; locality 23. U.S.N.M. 561055. Lepidocyclina (Nephrolepidina) chaperi Lemoine and R. Douvillé (p. 23). Vertical section, X 12.5, showing the slitlike cavities of the lateral chambers between thick roofs and floors; locality 125. U.S.N.M. 561056. . Vertical section, X 20, of a specimen with few lateral chambers; locality 125. U.S.N.M. 561057. . Vertical section, X 12.5, of a large well-developed specimen; locality 125. U.S.N.M. 561058. . Vertical section, X 12.5, of a specimen intermediate in development between the one illustrated as figure 4 and the one shown by figure 3; locality 125. U.S.N.M. 561059. . Vertical section, X 12.5, of a small specimen; locality 125. U.S.N.M. 561060. . Vertical sections, X 12.5, of typical specimens; locality 23. U.S.N.M. 561061. Vertical sections, X 12.5, of topotypes of Cushman’s “L. fragilis” from Ocala limestone at a cave, 200 yards below the former wagon bridge over the Chipola River near Marianna, Fla. U.S.N.M. 561062. Vertical section, X 12.5, of a compressed specimen of Cole’s “L. sanfernandensis tallahasseensis” showing the similarity among it, ”L. fragilis,” and L. chaperi; from Ocala limestone, City of Tallahassee water well no. 6 at a depth of 406 feet. U.S.N.M. 561063. Vertical section, X 12.5, of an inflated specimen of “L. sanfemandensis tallahasseensis” from same locality as figure 18. U.S.N.M. 561064. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244- PLATE 9 EOCENE LEPI DOC YCLI NA FIGURES 1—1 )—I 0. 1. 9? saw a e.w w PLATE 10 Lepidocyclina (Nephrolepz'dina) chaperi Lemoine and R. Douvillé (p. 23). , Equatorial section, X 12.5, of a topotype of Cushman’s “L. fragilis” with extremely large embryonic chambers in which the initial chamber is almost as large as the embracing second chamber; from Ocala limestone at a cave, 200 yards below old wagon bridge over the Chipola River near Marianna, Fla. U.S.N.M. 561065. . Equatorial section, X 12.5, of a topotype with smaller embryonic chambers than those possessed by the specimen illustrated as figure 1; from same locality as figure 1. U.S.N.M. 561066. Equatorial section, X 12.5, of a specimen having large embryonic chambers with the second chamber only slightly embracing the initial chamber; locality 125. U.S.N.M. 561067. . Equatorial section, X 12.5, of a specimen with embryonic chambers which are virtually lepidocycline s. s.; locality 125. U.S.N.M. 561068. Equatorial section, X 12.5, of a specimen with moderately nephrolepidine embryonic chambers; locality 125. U.S.N.M. 561069. . Equatorial section, X 20, of a specimen with rather small embryonic chambers; locality 125. U.S.N.M. 561070. Equatorial section, X 12.5, of a specimen with small embryonic chambers; locality 125. U.S.N.M. 561071. Equatorial section, X 12.5, of a specimen with embryonic chambers similar to those illustrated by H. Douvillé (1924, p. 45, fig. 37b); locality 23. U.S.N.M. 561072. Equatorial section, X 12.5; locality 125. U.S.N.M. 561073. Equatorial section, X 12.5, of a specimen whose second chamber strongly embraces the initial chamber; locality 23. U.S.N.M. 561074. ‘ GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 10 ., 9",!“ ‘ Evt.c‘fl‘:u_ ,0. . EOCENE LEPIDOC YCLINA PLATE 11 FIGURES 1—8. Lepidocyclina (Nephrolepidina) chaperi Lemoine and R. Douvillé (p. 23). 1, 2. Equatorial sections, X 12.5, of inflated specimens of Cole’s “L. sanfemandensis tallahasseensz's”; from Ocala limestone, City of Tallahassee water well no. 6 at a depth of 406 feet. U.S.N.M. 561075. 3. Equatorial section, X 12.5, of a thin specimen illustrating the individual variation in the size of the embryonic cham- bers; from same locality as figure 1. U.S.N.M. 561076. ’ 4—8. Equatorial sections, X 12.5, of Panamanian specimens to illustrate the variation which may occur in the size of the embryonic chambers. 4. Locality 125. U.S.N.M. 561077. 5. Locality 23. U.S.N.M. 561078. 6. Locality 140. U.S.N.M. 561079. 7, 8. Locality 125. U.S.N.M. 561080. GEOLOGICAL SURVEY , PROFESSIONAL PAPER 24-4 PLATE ll EOCEN E LEPI DOC YCLI NA FIGURES 1—15. 2. External views, X 5, of 2 topotypes of Cushman’ s “L. fragilis”; from Ocala limestone at a cave, 200 yards below the 1 3. 4—6. 10. 11. 12, 13. 14, 15. 16. PLATE l2 Lepidocyclina (Nephrolepidina) chaperi Lemoine and. R Douvillé (p. 23) former wagon bridge over the Chipola River near Marianna, Fla. U. S. N. M. 561081 Vertical section, X 12. 5, of a specimen at first identified as L. semmesi Vaughan and Cole; locality 125. U.S.N.M. 561082. Vertical sections, X 12.5, of specimens 'from the same sample showing individual variation; locality 125. U.S.N.M. 561083 Vertical section, X 12.5, of a microspheric specimen; locality 125. U.S.N.M. 561084. Part of an equatorial section, X 40, of a microspheric specimen showing the shape of the equatorial chambers; locality 125. U.S.N.M. 561085. . Vertical section, X 12.5; locality 140. U.S.N.M. 561086. Vertical section, X 12.5; locality 137. U.S.N.M. 561087. External View, X 5, of a megalospheric specimen; locality 23. U.S.N.M. 561088. External views, X 2, of tWO strongly selliform microspheric specimens; locality 23. External views, X 2, of two strongly papillate microspheriSc) specimens; locality 23. Lepzdocyclina (Pliolepidina) gubernacula Cole, n. sp. (p External gileleX 5, of the holotype showing the inflated, elevated margin characteristic of this species; locality 23. U. 561091. U.S.N.M. U. S. N M. 561089. 561090. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244- PLATE 12 EOCENE LEPIDOC YCLINA PLATE 13 FIGURES 1—-20. Lepidocyclina (Pliolepidina) pustulasa H. Douvillé (p. 16). 1—19. Vertical sections of megalospheric individuals showing the great variation which may occur in this species. 20; locality 149b. U.S.N.M. 561092. 12.5; locality 137. U.S.N.M. 561093. 20; locality 150. U.S.N.M. 561094. 20; locality 15. U.S.N.M. 561097. 20; locality 140. U.S.N.M. 561095. 20; locality 131a. U.S.N.M. 561096. 12.5; locality 137. U.S.N.M. 561098. 20; locality 140. U.S.N.M. 561099. 20; locality 140. U.S.N.M. 561100. 20; locality 140. U.S.N.M. 561101. 20; locality 149b. U.S.N.M. 561102. 20; locality 140. U.S.N.M. 561103. 20; locality 15. U.S.N.M. 561104. 20; locality 140. U.S.N.M. 561105. 40; locality 22a. U.S.N.M. 561106. 20; locality 140. U.S.N.M. 561107. 20; locality 149b. U.S.N.M. 561108. 20; locality 15. U.S.N.M. 561109. 40; locality 22a. U.S.N.M. 561110. 20. Vertical section, X 20, of a microspheric individual showing the strong pillars which end in large s‘urface pustules; locality 140. U.S.N.M. 561111. 21. Lepidocyclina (Pliolepidina) pustulosa tobleri H. Douvillé (p. 17). Vertical section, X 12.5, of a large, inflated specimen with the general configuration of typical L. pustulosa except for the embryonic chambers; introduced for comparison with L. pustulosa; locality 124. U.S.N.M. 561112. ._. o XXXXXXXXXXXXXXXXXXX PROFESSIONAL PAPER 244 PLATE 13 G EOLOGIC AL SURVEY EOCEN E LEPI DOC YCLI NA PLATE 14 FIGURES 1—10. Lepidocyclina (Pliolepidina) pustulosa H. Douvillé (p. 16). Equatorial section, X 20; locality 22a. U.S.N.M. 561113. Equatorial section, X 20; locality 22a. U.S.N.M. 561114. Equatorial section, X 20; locality 15. U.S.N.M. 561115. Equatorial section, X 20; locality 149b. U.S.N.M. 561116. Equatorial section, X 12.5; locality 140. U.S.N.M. 561117. Equatorial section, X 12.5; locality 140. U.S.N.M. 561118. Equatorial section, X 20; locality 15. U.S.N.M. 561119. . Equatorial section, X 20; locality 140. U.S.N.M. 561120. Equatorial section, X 20; locality 140. U.S.N.M. 561121. 10a—10d. External View, X 10, of 4 specimens showing individual differences; locality 140. U.S.N.M. 561122. 11. Lepidocyclina (Pliolepidina) macdonaldi Cushman (p. 16) Equatorial section, X 12.5, showing the difference in shape of the equatorial chambers between this species and L. pustulosa; locality 149b. U.S.N.M. 561123. 12, 13. Lepidocyclina (Pliolepidina) pustulosa tobleri H. Douvillé (p. 17). Equatorial sections, X 20; locality 132. U.S.N.M. 561124. Pmflewewpr PROFESSXONAL PAPER 244 PLATE 14 G EOLOGICAL SURV EY a: 5...“) l7¢‘(, . 5 In :6 I 8 H A. EOCENE LEPIDOC YCLINA FIGURES 1, 2, 4, 5. 1 PLATE 15 Lepidocyclina (Lepidocyclina) yurnagunensis morganopsis Vaughan (p. 23). , 2. Vertical sections, X 20, of megalospheric specimens showing the heavy pillars; locality 53. U.S.N.M. 561125. 4, 5. 3. Vertical sections, X 20, 0f microspheric individuals showing the heavy pillars; locality 45. U.S.N.M. 561127. Lepidocyclina (Lepidocyclina) yumagunensis Cushman (p. 22). Vertical section X 12.5, showing the lateral chambers in regular tiers and the absence of pillars; locality 45. U.S.N.M. 561126. . Lepidocyclina (Lepidocyclina) parvula Cushman (p. 20) Vertical section, X 20, of a megalospheric individual with heavy pillars; locality 11a. U.S.N.M. 561128. : Vertical section, X 20, of a microspheric individual with heavy pillars and thin floors and roofs to the lateral chambers;locality11a. U.S.N.M. 561129. . Vertical section, X 20, of a microspheric specimen with low irregular lateral chambers between thick roofs and floors; locality 39. U.S.N.M. 561130. . Equatorial section, X 20, of a microspheric individual; locality 39. U.S.N.M. 561131. . Equatorial section, X 20, of a megalospheric individual; locality 11a. U.S.N.M. 561132. . Lepidocyclina (Lepidocyclina) montgomeriensis Cole (p 20). . Equatorial section, X 12. 5; locality 125. U. S. N. M. 561139. . Vertical section, X 20, of a specimen with large embryonic chambers and very few lateral chambers; locality 125. U. S. N. M. 56.1140 . Vertical section, X 20; locality 125. U. S. N. M. 561141. . Lepidocyclina (Pliolepidma) pustulosa H. Douvillé (p. 16). . Equatorial section, X 20, of a specimen of the type called L. subglobosa Nuttall; locality 131a. U. S. N. M. 561133. . Vertical sections, X 20, of specimens of the type called L. subglobosa Nuttall; locality 131a. U. S. N. M. 561134. . Lepidocyclina (Pliolepidina) pustulosa tobleri H. Douvillé (p. 17). . Vertical section, X 12 5, of an inflated specimen; locality 124. U. S. N. M. 561135. . Vertical section, X 20, of a small lenticular specimen, locality 1491). U. S. N. M. 561136. . Vertical sections, X 20; locality 132. US. NM . M561137. . Equatorial section, X 20; locality 149b. U. -.S NM . 561138. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 15 EOCENE AND OLIGOCENE LEPIDOCYCLINA FIGURES 1—22 PLATE 16 . Lepidocyclina (Lepidocyclina) canellei Lemoine and R. Douvillé (p. 18.) . Vertical section, X 20; locality 53. U.S.N.M. 561142. . Vertical section, X 20; locality 11a. U.S.N.M. 561143. Vertical sections, X 20; locality 53. U.S.N.M. 561144. Vertical sections, X 20; locality 30. U.S.N.M. 561145. Vertical section, X 20; locality 43. U.S.N.M. 561146. Vertical sections, X 20; figure 9 is nearly an exact duplicate of the type vertical section given by Lemoine and R. Douvillé; locality 53. U.S.N.M. 561147. Vertical section, X 20; locality 43. U.S.N.M. 561148. . Vertical sections, X 20; station 53. U.S.N.M. 561149. . Vertical segtions, X 40, of topotypes of L. pancanalis Vaughan and Cole; U.S.G.S. locality 6025, Panama. U.S.N.M. 56115 . . Equatorial section, X 20; locality 43. U.S.N.M. 561151. Equatorialsection, X 20; locality 53. U.S.N.M. 561152. Equatorial section, X 20; locality 11a. U.S.N.M. 561153. . Equatorial section, X 40, of a topotype of L. pancanalis Vaughan and Cole; U.S.G.S. locality 6025, Panama. U.S.N.M. 561154. . Equatorial section, X 20; locality 43. U.S.N.M. 561155. . Equatorial section, X 20; locality 30. U.S.N.M. 561156. . Equatorial section, X 20, of the same. specimen illustrated as figure 18; U.S.G.S. locality 6025, Panama. U.S.N.M. 561157. . Equatorial section, X 20; locality 55. U.S.N.M. 561158. PROFESSIONAL PAPER 244- PLATE 16 GEOLOGICAL SURVEY §.. .u an é u u‘a. k. A‘ $31: LIGOCEN E LEPI DOC YCLI NA 0 FIGURES 1—3. la—lb. 2a—2d. . Equatorial section, X 20, which is similar to the type section figured by Lemoine and R. Douvillé (1904, p]. 3, fig. 5); PLATE 1 7 Lepidocyclina (Lem'docyclina) canellei Lemoine and R. Douvillé (p. 18). External view, X 10, of 2 large specimens; locality 53. U.S.N.M. 561159. External view, X 10, of 4 small specimens of the type called L. pancanalis Vaughan and Cole; locality 43. U.S.N.M. 561160. locality 53. U.s.N.M. 561161. . Lepidocyclina (Lepidocyclina) asterodisca Nuttall (p. 17). External view, X 5, of the only available specimen show— ing the radiate character of the test; locality 110. U.S.N.M. 561162. . Lepidocyclina (Lepidocyclina) yurnagunensis Cushman (p. 22). . Vertical sections, X 20; locality 45. U.S.N.M. 561163. . Vertical section, X 20, of a very compressed specimen; locality 54. U.S.N.M. 561164. . Vertical section, X 20, of a strongly inflated specimen; locality 45. U.S.N.M. 561165. . Vertical sections, X 20; locality 54. U.S.N.M. 561166. . Vertical sections, X 20; localitv 45. U.S.N.M. 561167. . Equatorial section, X 20; locality 39. U.S.l\'.M. 561168. . Equatorial section, X 20; locality 54. U.S.N.M. 561169. . Equatorial section, X 20; locality 45. U.S.N.M. 561170. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 1'] OLIGOCENE LEPI DOC YC LI NA FIGURES 1—10, 16, 17. 1. Vertical section, X 20; locality 38. U.S.N.M. 561171. 2-4. 5—7. 10. 16. 17. 11. 12. 13. 14, 15. 14. Part of a vertical section, X 20, not centered, to show the open, rectangular lateral chambers with thin roofs 15. PLATE 18 Lepidocyclina (Lepidocyclina) waylandvaughani Cole (p. 20). Vertical sections, X 20; locality 11a. U.S.N.M. 561172. Vertical sections of topotypes introduced for comparison with the Panamanian specimens; 5, 6, X 12.5; 7, X 20; collected by W. S. Cole, on the Huasteca Petroleum Company’s golf course, Tampico, Mexico, from the Meson formation. U.S.N.M. 561173. Vertical section, X 20, of a Panamanian specimen which has features identical to those shown by the Mexi- can specimen, fig. 7; locality 11a. U.S.N.M. 561174. Part of a vertical section, X 40, of a Panamanian specimen showing the open, rectangular cavities of the lateral chambers; locality 11a. U.S.N.M. 561175. Part of a vertical section, X 40, of the topotype illustrated as figure 6, introduced for comparison with the Panamanian specimen, figure 9; collected by W. S. Cole, on the Huasteca Petroleum Company’s golf course, Tampico, Mexico, from the Meson formation. U.S.N.M. 561173. Part of an equatorial section, X 12.5, of a topotype introduced for comparison; collected by W. S. Cole, on the Iguasteca Petroleum Company’s golf course, Tampico, Mexico, from the Meson formation. U.S.N.M. 5611 3. Part of an equatorial section, X 20, showing the thick-walled, bilocular embryonic chambers and the short- spatulate to hexagonal equatorial chambers; locality 11a. U.S.N.M. 561176. Lepidocyclina (Lepidocyclina) forresti Vaughan (p. 21). Part of a vertical section, X 40, of a cotype which has lateral chambers similar to those found in L. supera (Conrad); photograph by Lloyd Henbest; specimen originally illustrated by Vaughan (1927, pl. 2, fig. 1); from the Antigua formation, east of Willo'ughby Bay, Antigua. U.S.N.M. 561177. Lepidocyclina (Lepidocyclina) supem (Conrad) (p. 21). Part of a vertical section, X 40, introduced to illustrate the differences in vertical section between it and L. ' waylandvaugham‘ and the similarities between it and L. forresti; from the Byram formation, Vicksburg, Miss. U.S.N.M. 561178. Lepidocyclina (Lepidocyclina) mantelli (Morton) (p. 21). Part of a vertical section, X 40, to show the features of the vertical section; collected by W. S. Cole from the Marianna limestone on the Chipola River one-half mile east of Marianna, Fla. U.S.N.M. 561179. Lepidocyclina (Nephrolepz'dina) vaughani Cushman (p. 21). and floors; locality 11a. U.S.N.M. 561180. Part of an oblique ”vertical” section, X 20, not centered, made to resemble Cushman’s (1919a) illustration figure 5, plate 37, which Vaughan (1923) used as a cotype for L. mirafiorensis; locality 30. U.S.N.M. 561181. \ \ GEOLOGICAL SURVEY PROi‘ESSIONAL PAPER 244 PLATE 18 \3-«1‘ .75v-o... OLIGOCENE LEPI DOC YCLINA ‘ FIGURES 1—8. 1, 2. 3—5. PLATE 19 Lepidocycli'na (Nephrolepidina) dartom‘ Vaughan (p. 27). External view, X 10, of 2 specimens showing the surface appearance and the radiate character of the test; locality 11a. U.S.N.M. 561182. ' Vertical sections, X 20, showing the large, rectangular lateral chambers arranged in rather regular tiers; locality 11a. U.S.N.M. 561183. . Equatorial section, X 20, showing the equatorial chambers arranged in a stellate pattern; locality 11a. U. S. N. M. 561184. . Equatorial section, X 20, of a specimen whose radiate pattern is less distinct than that of figure 6 in which the shape of the equatorial chambers varies from diamond to elongate hexagonal; locality 11a. U.S.N.M. 561185. . Equatorial section, X 20, of a specimen with very small embryonic chambers; locality 11a. U.S.N.M. 561186. . Lepidocyclina (Nephrolepidina) tournoueri Lemoine and R. Douvillé (p. 28). . Equatorial section, X 20, which has elongate hexagonal equatorial chambers to the right of the embryonic chambers of the type assumed to characterize L. tempam'z' Vaughan and Cole, and which has equatorial chambers of the type associated with typical L. tournoueri to the left of the embryonic chambers; locality 45. U.S.N.M. 561187. . Equatorial section, X 20; locality 45. U.S.N.M. 561188. . Vertical sections, X 20; locality 45. U.S.N.M. 561189. 0 PROFESSIONAL PAPER 24-4 PLATE l9 GEOLOGICAL SURVEY . I 17.. ’ 0‘- 9 to OLIGOCENE LEPIDOC YCLINA FIGURES 1—6. . Vertical section, X 20; locality 38. U.S.N.M. 561190. . Vertical section, X 20; locality 43. U.S.N.M. 561191. . Vertical section, X 20; locality 37. U.S.N.M. 561192. . Vertical section, X 12.5; locality 121. U.S.M.N. 561193. 8—10. . Equatorial section, X 12.5, of a strongly selliform individual; locality 23. U.S.N.M. 561197. . Equatorial section, X 12.5, of a specimen with embryonic chambers in which the second chamber does not embrace 10. 11, 12. . 11. Equatorial section, X 20, in which the embryonic chambers tend toward the nephrolepidine type; locality 54. 12. 13. 14, 15. 14. 15. 16. 17. PLATE 20 Lepidocyclina (Nephrolepidina) vaughani Cushman (p. 29). Equatorial section, X 12.5; locality 121. U.S.N.M. 561194. Part of an equatorial section, X 20; locality 30. U.S.N.M. 561195. . Lepidocyclina (Lepidocyclina) montgomen’ensis Cole (p. 20). Vertical section, X 12.5, of a specimen with more open cavities to the lateral chambers than is usual for this species; locality 125. U.S.N.M. 561196. Lepidocyclina (Nephrolepidina) chaperi Lemoine and R. Douvillé (p. 23). the initial chamber; locality 150. U.S.N.M. 561198. Part of an equatorial section, X 20, in which the embryonic chambers are lepidocycline; locality 140. U.S.N.M. 561199. Lepidocyclina (Lepidocyclina) yumagunensis Cushman (p. 22). U.S.N.M. 561200. Vertical section, X 20; locality 45. U.S.N.M. 561201. Helicolepz'dina spiralis Tobler (p. 30). Vertical section, X 40, of a small individual resembling certain small specimens of L. pustulosa except for its equa- torial spire which is shown by an enlarged chamber at the place where it cuts the equatorial layer; locality 22a. U.S.N.M. 561202. Lepidocyclina (Pliolepidina) pustulosa H. Douvillé (p. 17). Vertical section, X 40, of a small individual with thin roofs and floors to the lateral chambers; locality 22a. U.S.N.M. 561203. Equatorial section, X 40, showing the equatorial and embryonic chambers; locality 22a. U.S.N.M. 561204. Lepidocyclina (Pliolepidina) macdonaldi Cushman (p. 16). Vertical2sgsction, X 12.5, of a specimen which probably should be assigned to this species; locality 132. U.S.N.M. 561 . Lepidocyclina (Pliolepidina) gubernacula Cole, n. sp. (p. 15). Part of an equatorial section, X 12.5, showing the shape of the equatorial chambers; locality 23. U.S.N.M. 561206. PROFESSIONAL PAPER 244 PLATE 20 GEOLOGICAL SURVEY ‘0, P . z. w .3 ’ ’1 K . 5“ 9:0 AND EOCENE HELICOLEPIq) NA EOCENE AND OLIGOCENE LEPIDOCYCLINA FIGURES 1—15. PLATE 2 1 Lepidocyclina (Nephrolepidina) vaugham' Cushman (p. 29). 1. Part of an equatorial section, X 12.5, showing an abnormal development of the embryonic chambers; locality 123. 2, 11. 12. 14. 15. U.S.N.M. 561207. . Parts of equatorial sections, X 20; figure 2 shows the stoloniferous opening between the initial and the second em- bryonic chamber; locality 38. U.S.N.M. 561208. Parts of an equatorial section, X 12.5, showing well-developed embryonic and equatorial chambers; locality 30. U.S.N.M. 561209. Equatorial chambers, X 40, from the upper right part of the specimen illustrated as figure 4, showing details of their shape; locality 30. U.S.N.M. 561210. . Vertical section, X 12.5, showing the greatly increased height of the equatorial chambers in the inflated margin of the test; locality 30. U.S.N.M. 561211. Vertical section, X 20, of the central part of an incomplete specimen; locality 11a. U.S.N.M. 561212. : Vertical section, X 12.5; locality 30. U.S.N.M. 561213. . Vertical section, X 12.5, of a specimen with few lateral chambers on each side of the embryonic chambers; locality 123. U.S.N.M. 561214. . Vertical section, X 12.5; locality 11a. U.S.N.M. 561216. Vertical section, X 20, of the central, inflated part of an incomplete and broken specimen; locality 38. U.S.N.M. 561215. Vertical section X 12.5; locality 43. U.S.N.M. 561217. . Part of an equatorial section, X 20; locality 37. U.S.N.M. 561218. Part of an equatorial section, X 12.5, of a specimen with very large embryonic chambers; locality 43. U.S.N.M. 561219. External view, X 5, showing the small but pronounced central umbo and the elevated edge of the test; localit‘y~30. U.S.N.M. 561220. GEOLOGICAL SURVEY PROFESSIONAL PAPER 24-4 PLATE 21 OLIGOCEN E LEPI DOC YC LI NA FIGURES 1-—5. 1—3. PLATE 22 Lepidocyclina (Eulepidina) favosa Cushman (p. 30). Vertical sections, X 12.5, of microspheric individuals; locality 38. U.S.N.M. 561221. 4. Vertical section, X 12.5, of a megalospheric individual; locality 39. U.S.N.M. 561222. 5. 6—8. 6 7. 8. 9. Part of an equatorial section, X 12.5, of a megalospheric specimen; locality 39. U.S.N.M. 561223. Lepidocyclina (Eulepidina) undosa Cushman (p. 30). Part of an equatorial section, X 12.5, of a megalospheric specimen; locality 45. U.S.N.M. 561224. Vertical section, X 20, of a megalospheric specimen whose surface is so eroded that the lateral chambers are largely missing; locality 45. U.S.N.M. 561225. ‘ Verticalzsection, X 20, not centered, showing the equatorial layer and lateral chambers; locality 45. U.S.N.M. 561 26. Lepidocyclina gigas Cushman (p. 30). Vertical section, X 12.5, virtually centered; locality 39. U.S.N.M. 561227. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 22 OLIGOCENE LEPI DOC YCLI NA FIGURES 1—3, 10. 1. External view, X 10, of a microspheric specimen with well-developed, raised, 2. 3. 10. 5—7, 9. 5 6 7 9 8,11,12 8 11 12 13 PLATE 23 Le idoc clina (Pliole idina) ustulosa H. Douvillé ( . 16). . P y P P p umbonal pustules; locality 140. U.S.N.M. 561228. Equatorial section, X 20, of a microspheric specimen; locality 131a. U.S.N.M. 561229. . Detail of figure 2, X 40, showing the initial spire and the shape of the equatorialchambers; locality 131a. U.S.N.M. 561229. Vertical section, X 12.5, of a microspheric specimen; locality 137. U.S.N.M. 561238. Lepidocyclina (Lepidocyclina) montgomeriensis Cole (p. 20). Detail, X 40, of equatorial chambers from part of the specimen illustrated on plate 15, figure 13; locality 125. U.S.N.M. 561230. Lepidocyclina (Lepidocyclina) yurnagunensis morganopsis Vaughan (p. 23). . Vertical section, X 12.5, of a microspheric specimen with very strong pillars; locality 39. U.S.N.M. 561231. . Vertical section, X 12.5, of a microspheric specimen with moderate pillars; locality 45. U.S.N.M. 561232. . Vertical section, X 12.5, of a specimen with few pillars near the center; locality 11a. U.S.N.M. 561233. . Vertical section, X 12.5, locality 45. U.S.N.M. 561235. . Lepidocyclina (Nephrolepidina) chapen' Lemoine and R. Douvillé (p. 23). . . Vertical section, X 12.5, of a microspheric specimen of the type called L. subraulinii; locality 125. U.S.N.M. 561234. . Part of an equatorial section, X 20, of a microspheric topotype of Cushman’s “L. fragilis” showing the shape of the equatorial chambers; from Ocala limestone at a cave 200 yards below old wagon bridge over the Chipola River near Marianna, Fla. U.S.N.M. 561236. . Part of an equatorial section, X 12.5, of a microspheric specimen from Panama showing the shape of the equatorial chambers; locality 23. U.S.N.M. 561237. . Lepidocyclina (Pliolepidina) gubernacula Cole, n. sp. (p. 15). Vertical section, X 12.5, showing well-developed pillars in the umbonal area; locality 23. U.S.N.M. 561239. PROFESSIONAL PAPER 244 PLATE 23 GEOLOGICAL SURVEY EOCENE AND OLIGOCENE LEPIDOCYCLINA FIGURES 1—16. D—‘b-‘D—lp-A w s mna 16. l7a—l7d. rowwssaew we PLATE 24 Helicolepidina spiralis Tobler (p. 30). External view, X 10, of a slightly eroded specimen; locality 125. U.S.N.M. 561240. External View, X 5, of a large specimen with a sharply inflated umbo and a distinct rim; locality 125. U.S.N.M. 561241. External view, X 5, of a. small specimen; locality 125. U.S.N.M. 561242. Vertical section, X 12.5, of a typical large specimen; locality 125. U.S.N.M. 561243. Vertical section, X 20, of a well-developed specimen; locality 150. U.S.N.M. 561244. Vertical section, X 20, of a small specimen similar to Vaughan’s “H. nortom’”; locality 125. U.S.N.M. 561245. Equatorial section, X 12.5; locality 125. U.S.N.M. 561246. Equatorial section, X 20, which shows the spiral chambers clearly; locality 125. U.S.N.M. 561247. . Equatorial section, X 12.5; locality 125. U.S.N.M. 561248. . Equatorial section, X 20; locality 125. U.S.N.M. 561249. Equatorial section, X 20, of a specimen which does not show the spire clearly; the indistinct spire is supposed to be a characteristic of Vaughan’s “H. nortoni”; locality 22a. U.S.N.M. 561250. Vertical section, X 40, of a specimen similar to “H. nortom’” and also small H. spiralis; locality 22a. U.S.N.M. 561251. Vertical section, X 20, of a specimen which is similar to the topotype of “H. nortom'” illustrated as figure 14; locality 22a. U.S.N.M. 561252. Vertical sections, X 20, of topotypes of “H. nortom‘” introduced for comparison; from Jackson formation in well sample ata depth of 3611—3612 feet in sec. 20, T. 68., R. 5E., St. Landry Parish, La. U.S.N.M. 561253. Equatorial section, X 20, of a topotype of “II. nortoni;” same locality as above. U.S.N.M. 561254. Miogypsina (Illiogypsina) antillea (Cushman) (p. 35). External View, X 15, of 4 specimens showing the shape and external sculpture; locality 53. U.S.N.M. 561255. GEOLOGICAL SURVEY PROFESSIONAL PAPER 24-1 PLATE 24 . § . ‘ - ' “fl!” ~‘1 uh n uh 3.1.... ”44‘ ”Z ’ 134",- m- '3...» _ ¢ 1 ‘ n. I Z EOCENE HELICOLEPIDINA AND OLIGOCENE MIOCYPSINA FIGURES 1— . PLATE 25 Miogypsz‘na (Miolepidocyclina) panamensis (Cushman) (p. 36). . Vertical section, X 40, of the inflated type; locality 55. U.S.N.M. 561256. . Equatorial section, X 40, showing embryonic, periembryonic, and equatorial chambers; locality 55. U.S.N.M. 561257. 8 1 2 3. Equatorial section, X 40, of an inflated specimen; locality 55. U.S.N.M. 561258.- 4. 5 6 7 Equatorial section, X 40; locality 55. U.S.N.M. 561259. . Equatorial section, X 40, of an inflated specimen; locality 55. U.S.N.M. 561260. . Transverse section, X 40, of a compressed specimen; locality 55. U.S.N.M. 561261. . Equatorial section, X 20, of a compressed specimen; locality 55. U.S.N.M. 561262. . thernal view, X 15, of 4 individuals showing varying degrees of inflation and the surface ornamentation; locality 55. U.S.N.M. 561263. . Miogypsina (Miolepidocyclina) mexicana Nuttall (p. 36). Equatorial section, X 40, introduced for comparison with M. panamensis; from lower Oligocene, northeast of Finca de los Tremari, Veracruz, Mexico. U.S.N.M. 561264. . Vertical section, X 40, introduced for comparison with M. panamensis. U.S.N.M. 561265. . Equatorial sections, X 20, introduced for comparison With M. panamensis. U.S.N.M. 561266. . Miogypsz'na (Miogypsina) antillea (Cushman) (p. 35). ‘ . Vertical section, X 20, not centered; locality 53. U.S.N.M. 561267. . Vertical section, X 40; locality 53. U.S.N.M. 561268. 1 . Equatorial section, X 40; locality 53. U.S.N.M. 561269. GEOLOGICAL SURVEY . PROFESSIONAL PAPER 244 PLATE 25 OLIGOCENE MIOG YPSINA FIGURES 1—20. 1. External view, X 10, of a Cuban specimen of Vaughan’s ”A. ruttem'” with a few raised large, umbonal pustules; 2 3 4 5 6. 7 8 9 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. PLATE 26 Asterocyclina minima (Cushman) (p. 32). from the upper Eocene at Palmer’s locality 1102, 4.5 km west of Guanajay on the road to Mariel, Pinar del Rio Province, Cuba. U.S.N.M. 561270. . External View, X 10, of a Panamanian specimen with a few large umbonal pillar-heads which are flush with the surface of the test; locality 140. U.S.N.M. 561271. . External View, X 15, of a Panamanian specimen with projecting rays, a few large raised umbonal pustules, and many smaller pustules; locality 22a. U.S.N.M. 561272. . External view, X 10, of a Cuban specimen with many short rays and small pustules evenly distributed over the umbo; from upper Eocene, at same locality as figure 1. U.S.N.M. 561273. . External View, X 10, of a Panamanian specimen with a few large ,slightly raised umbonal pustules; locality 140. U.S.N.M. 561274. Enlarged detail, X 40, of figure 7 showing the embryonic and equatorial chambers; locality 22a. U.S.N.M. 561275. . Equatorial section, X 20, of a specimen similar to the one illustrated as figure 3; locality 22a. U.S.N.M. 561275. . Vertical section, X 20, of a Cuban specimen similar to the one illustrated as figure 1; from upper Eocene, same locality as figure 1. U.S.N.M. 561276. . . Vertical section, X 20, of a Cuban specimen similar to the one illustrated as figure 1 except the umbonal surface is devoid of pustules; from upper Eocene, same locality as figure 1. U.S.N.M. 561277. Vertical section, X 20, of a Cuban specimen which is similar to the one called A. sculpturata (Cushman by Vaughan (1945, pl. 31, fig. 2, the first specimen on the left); from upper Eocene, same locality as figure . U.S.N.M. 561278. Vertical section, X 20, of a Cuban specimen similar in external appearance to the one illustrated as figure 4; upper Eocene, same locality as figure 1. U.S.N.M. 561279. Vertical section, X 20, of a Cuban specimen similar in external appearance to the one illustrated as figure 1; from upper Eocene, same locality as figure 1. U.S.N.M. 561280. Vertical section, X 20, of a Cuban specimen similar in external appearance to the one illustrated by Vaughan (1945, pl. 31, fig. 2, the third specimen from the left) under the name A. sculpturala (Cushman); from upper Eocene, same locality as figure 1. U.S.N.M. 561281. Vertical section, X 20, of the holotype of A. minima (Cushman) photographed by transmitted light by Lloyd Henbest; U.S.G.S. locality 6512, David, Panama. U.S.N.M. 324745. Vertical section, X 20, of the holotype of A. minima (Cushman) taken by dark field illumination by Lloyd Henbest to show the well-developed pillars, the thin roofs and floors of the lateral chambers, and the open, rectangular cavities of these chambers; U.S.G.S. locality 6512, David, Panama. U.S.N.M. 324745. Vertical section, X 20, of a Panamanian specimen which was identified at first as A. sculpturaw (Cushman); locality 22a. U.S.N.M. 561282. Vertical section, X 20, of a Panamanian specimen which was identified as A. minima (Cushman); locality 140. U.S.N.M. 561283. Vertical section, X 20, of a Panamanian specimen which was identified from external view as A. mttem' Vaughan; locality 140. U.S.N.M. 561284. Vertical section, X 20; locality 22a. U.S.N.M. 561285. Vertical section, X 20, of a Panamanian specimen which was identified by external characters as A. sculpturata (Cushman); locality 140. U.S.N.M. 561286. "CE“ 1,; WW 9:? GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 26 a" h. in .. g“ EOCENE ASTEROCYCLINA FIGURES 1—5. 1. 2. 3. External view, X 10, of a Cuban specimen introduced for comparison; from upper Eocene, at Palmer’s locality 1102. 4, 5. 6—12. . Detail of figure 7, X 40, showing the embryonic chambers and the elongate equatorial chambers of the rays; locality 6 7. , 9. 10. ll. 12a—12b. 8 PLATE 27 Asterocyclina mariannensis (Cushman) (p. 31). Vertical section, X 20, of a large specimen; locality 140. U.S.N.M. 561287. Vertical section, X 20, of a small specimen; locality 140. U.S.N.M. 561288. 4.5 km west of Guanajay on the road to Mariel, Pinar del Rio Province, Cuba. U.S.N.M. 561289. External views, X 10, of Panamanian specimens showing individual differences; locality 140. U.S.N.M. 561290. Asterocyclina georgiana (Cushman) (p. 31). 125. U.S.N.M. 561291. Equatorial section, X 12.5; locality 125. U.S.N.M. 561291. Vertical sections, X 20, showing individual differences; locality 125. U.S.N.M. 561292. External view, X 10, showing well-developed rays and only slight interray areas; locality 124. U.S.N.M. 561293. External view, X 10, showing well-developed interray areas; locality 145. U.S.N.M. 561294. Extergal2views, X 10, of 2 specimens, the lower one of which has heavy pillars along the rays; locality 125. U.S.N.M. 5 1 95. . GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 27 EOCENE ASTEROCYCLINA FIGURES 1-4. 1. S" 9????“99.” PLATE 28 Asterocyclina mariannensis (Cushman) (p 31). Vertical section X 20, showing long, low lateral chambers in regular tiers and heavy umbonal pillars; locality 140. U. S. N.M . 561296. Equatorial section, X 20; locality 140. U.S.N.M. 561297. Equatorial section, X 12.5; locality 140. U.S.N.M. 561298. Equatorial section, X 20; locality 140. U.S.N.M. 561299. Asterocyclina minima (Cushman) (p. 32). Equatorial section, X 20; locality 140 U S. N M 561300. Part of an equatorial section, X 40, showinMg embryonic chambers and the arrangement of the equatorial chambers to produce rays; locality 140. U. S. NM . 561301. Pseudophragmina (Proporocyclma) flimensis (Cushman) (p. 35). Vertical section, X 20, showing a lenticular test of the type of P. citrensis (Vaughan); locality 125. U.S.N.M. 561302. Vertical section, X 20, showing a nonumbonate test of the type of P. mirandana (Hodson); locality 140. U.S.N.M 561303. Vertical section, X 20, showing a lenticular test with a strong umbo; locality 125. U. S. N M. 561304. VertichalS section, X 20, showing a compressed umbonate test of the type of P. flintensm (Cushman); locality 140. N M 561305 . Vertical section, X 20, not centered; locality 140. U.S.N.M. 561306. . Part of an equatorial section, X 40, showing the embryonic and periembryonic chambers; locality 140. U.S.N.M. 13, 14. 16. 561307. Parts of equatorial sections, X 40, showing the embryonic and equatorial chambers, locality 125. U.S.N.M. 561308. External view, X 10; locality 125. U. S. N. M. 561309. External v1ew X 10; locality 140. U.S.N.M. 561310. GEOLOGICAL SURVEY PROFESSIONAL PAPER 244 PLATE 23 EOCENE ASTEROCYCLINA AND PSEUDOPHRAGMINA ,3 ta; » five”, “I "vagw‘ ‘3‘”). k . 511.1; 1.2+!er