Cornell Mniwersity Hibrary N20 BB eee is\er jz 1357 | aes om MARYLAND GEOLOGICAL SURVEY LOWER CRETACEOUS MARYLAND GEOLOGICAL SURVEY LOWER CRETACEOUS BALTIMORE THE JOHNS HOPKINS PRESS 1911 A 4 n The Bord Baltimore Press BALTIMORE, MD., U. 8. A. COMMISSION AUSTIN L. CROTHERS, 5 3 ‘5 . ‘ PRESIDENT. GOVERNOR OF MARYLAND. CHARLES H. STANLEY, COMPTROLLER OF MARYLAND. TRA REMSEN, ‘ : : ‘ « EXEOUTIVE OFFICER. PRESIDENT OF JOHNS HOPKINS UNIVERSITY. R.W.SILVESTER, . . . . . . SrORBTARY. PRESIDENT OF MARYLAND AGRICULTURAL COLLEGE. SCIENTIFIC STAFF WM. BULLOCK CLARK, : 5 : ‘ STATE GEOLOGIST. SUPERINTENDENT OF THE SURVEY. EDWARD B. MATHEWS, ; . AsgsisTANT STATE GEOLOGIST. CHARLES K. SWARTZ, : ‘ ‘ j ‘ GEOLOGIST. EDWARD W. BERRY, ; ; : : ; '‘ GEOLOGIST. B. L. MILLER, ‘ : : : ‘ ‘ x GEOLOGIST. A. B. BIBBINS, i ‘ : : ‘ : GEOLOGIST. LETTER OF TRANSMITTAL To His Excellency Austin L. CrotTuers, Governor of Maryland and President of the Geological Survey Com- mission, Sir:—I have the honor to present herewith the fourth volume of a series of reports dealing with the systematic geology and paleontology of Maryland. The preceding volumes have dealt with the Tertiary and Quaternary deposits and the remains of animal and plant life which they contain. The present volume treats of the Lower Cretaceous deposits and their contained life, a knowledge of which is very important from an educational and scientific standpoint. JI am, Very respectfully, WM. BULLOCK CLARK, State Geologist. Joans Hopkins UNIVERSITY, Batrrmore, September, 1911. CONTENTS PAGE PREEACED sissies ca aiecie 40 aye -auayitoe oa eons vk Guha vous: sw iuaaa ane QNeMIp a Aue gacabanie as apesk Sah 17 THE LOWER CRETACEOUS DEPOSITS OF MARYLAND. By Wm. BULLOcK CLARK, ARTHUR B. BIBBINS, AND Epwarp W. BERRY...... 23 TN TRODUCTION:: «$55 scsio.d.sacaceponienansl ogy bvdsavoden.e-e auasd ead ae Od Fa Sears aaa 23 THE PH YSIOGRAPEY® 44 6 ss. soi spe sos ee aw ane Oe hea S eae tes Waa Wacdieee sls & 23 THE GRHOLOGY® jis 5 aie es Gash ad RE Oa ares BERT SEARS URE TS canes Bele y 4 26 CL CLWCEOUS osciisse Silasasdikavoen = &muauans ow Avann 398 Roane oa Gpvgnnh dee aon Deane aL ds 28 LOWE? CrEtAGGOUS: eis. cceeieere cea tanta meng Meneame 28 Upper Cretaceous) 0% .nid vices ceeds ecedes eee ca eases 29 Tertiary ........ PesAivense yt veegia tole Lessa aon opener Whleud comedian aussereonsi seer uate 30 HOGENE. sada ni Ss bon ek Sede ee eee eran eS 30 MiQCene? “wiid < wiagisc age eeabin eax Gel catia’: Dawe ovGertee ahaa 31 Pliocene 2c sasees .sae a ahs sea hed Oca Seed penne 23% 32 QUAL OTN OTY & fics x Geass eases Suiudn eave 0,06 apeilave 4 Upne-@ ek el enana ea Bayh oa ive 32 PIGIBLOCENE® 2.80.5 gov cdee taihnd dus wise eG MES BERENS 32 Recent. scxcanaciciwe ves gee ee te vis ee ee eSer Twente eee ss 33 HISTORIC AT: REVI W. foo ett: 22e.sis se Gubhe, Bes: akae) Was. Soden a Seanad ea Gkdye S-Se gee Reeael doar 34 BIBLIOGRAPHY ............. sist dah thbsip ds dada yg Seaoe (Sp ayBeavnlava Case esa kas Brads Speers Re 47 ‘STRATIGRAPHIC AND PALEONTOLOGIC CHARACTERISTICS. ..-..00 sees eevee 56 THE POTOMAC GROUP si cch tite vee eee eewhe ea she ce eee Esa RESO 57 The Patuxent Formation. .... 0... cece cece cece e ence nnaee «(58 Name and SynonyMy...........ccse cece ceceeeeeee 58 Areal Distribution. sicissc0ccce sk cvee cess eeaaees 58 Lithologic Character ............ccseeeeeeceeeeeee 58 Strike, Dip, and Thickness............. aisha separa oa 60 Stratigraphic and Structural Relations............. 61 Organic: Remains asc so sevece oss ciesatsuce diese 8c dover cea dune eee 63 The Arundel FOrmation..... 2c. c ccc cece cece ee eee nee enas 64 Name and Symonymy.............. eee ee eee erences 64 Areal Distribution ....... 0.0... cece cece cence eee 64 Lithologic Character .............. Pd Santa pu cade a toe 64 Strike, Dip, and Thickness.................... sani 65 Stratigraphic and Structural Relations............. 66 Organic Remains ..........c cece eee e rere eset tees 66 The Patapsco Formation....... pishenk oy ame Gea eats gaa clea ecratints 67 Name and SymonyMy.......... cece eee e cee eee eee 67 Areal Distribution ........... ce cece cece ee eee eee 68 Lithologic Character ....... 2... cc esc ce even eeeraee 68 Strike, Dip, and Thickness...............0eeeeeeee 69 Stratigraphic and Structural Relations............. 70 Orfanic: RémMains: siaccsoncca wait ens eensee ewan oes TW LOcal Sections ss aes wavs eee as age es R0G os wee ca ee os Be RE OK 72 14 CONTENTS PAGE INTERPRETATION OF THE POTOMAC: DEPOSITS.........seceececceeeecret? 80 Surface Configuration of Crystalline Floor and Its Rela- tion to Potomac Basin of Deposition........+-- 86 Surface Configuration of Potomac Deposits and Its Pos- sible Interpretation ..........cceeeeeeeeeeneee 87 DISTRIBUTION OF THE FAUNA AND FLORA.........00cceeeeeeeeeeeeeete 89 THE GEOLOGIC PROVINCE........0cccc cece eee e cent ence eee een eeneee 96 THE LOWER CRETACEOUS FLORAS OF THE WORLD. By EDWARD W. BERRY s2dccuceniineressaawrs nade news TK RE SAREE OSG Sains 99 THE NEOCOMIAN STAGE... . ccc cece cece ence ete e eee e eee e ee eet 101 THE BARREMIAN STAGE..... sees Lene daa) ages ghadise hea acconesepo’ ioheaduas won REE 127 THE; APTIAN STAGE ednagin ia sigue aware hae ateeneanioe nas eae te 135 THE ALBIAN STAGE y wssccciswes ciaaas See beams ey Meee ae eet ON 141 GENERAL CHARACTER AND DISTRIBUTION. ...... ee ceeeeeceeeereeeeee 146 CORRELATION OF THE POTOMAC FORMATIONS. By Epwarp W. BERRY cis aspen ia vinta an deen naatnmnia nine iam shah ne anaeasilataneerhndancienecEA 153 THE EUROPEAN FLORAS....... ccc cece cece e cece erence eee eeeennes 159 THE TRINITY FLORA OF TEXAS. 1... 0c cece eee c eee eee eee eeeeee 161 THE LAKOTA FLORA OF THE BLACK HILLS. ....... 0000 c cee eee eeeeee 162 THE FUSON FLORA OF THE BLACK HILLS. ....... 00 c eee e eee eer eens 162 THE KOOTANIE FLORA 2 55442400280 900 Sees Na eee RRR EARS en Sagres 162 THE UPPER KNOXVILLE FLORA.... 1... cece eee ene eee tee enees 164 THE HORSETOWN FLORA... ... 0 eee ee cee ee cence cece en enen renee 164 GENERAL CONSIDERATIONS ..... oneal ain PRU et aistotenatsl al maaranes eee ee 165 THE REPTILIA OF THE ARUNDEL FORMATION. By RicHarp SWANN TSU caisiae case Ainuma aston alates ~ A SDNGi aa SeeVa Dv al a a ERI BER 173 SYSTEMATIC PALEONTOLOGY, LOWER CRETACEOUS.............. 181 VERTEBRATA. RICHARD SwANN LULL............06 0% iatiolepumin’ 4 183 MoLLuscA. WM. BULLOCK CLARK. ......0.ccec cece eee nee eeeenaeees 211 PTERIDOPHYTA. EDWARD WILBER BERRY........... i Migiteaaniabernedes tatoldaenesdans 214 CycapopHyT#, EDWARD WILBER BERRY..............ceceeeeeeaveees 313 GYMNOSPERM@. EDWARD WILBER BERRBY..........0 2 ccc een cence ees 370 MonocotyLepon&. Epwarp WILBER’ BERRY..... eens cant enieaaseaiie 452 ‘DicoryLepoNa. EDWARD WILBER BERRY............-.00eeeeeeeececs 457 GENERAL INDEX, sie cider iceegin wldaines Gite angen nenannar sees Heese 597 PALEONTOLOGICAL INDEX ............ Reig COE DIRS ERR a. Manda oatmmens aie 605 PLATE II. IIT. IV. VI. VII. VIII. IX. ILLUSTRATIONS FACING PAGE Map showing Distribution of Potomac Deposits in Maryland...... Fig. 1—View showing basal conglomerate of the Patuxent over- lying the Piedmont Crystallines at Roland Park, Baltimore City Fig. 2.—View showing Patuxent arkosic sands and gravel in B. & O. R. R. cut at Savage, Anne Arundel County................. Fig. 1—View showing coarse, highly inclined and cross-bedded Patuxent sands near Homestead, Baltimore City.............. Fig. 2—View showing kaolin in the Patuxent formation in cut on P. B. & W. R. R. near Perryville, Cecil County................. Fig. 1—View showing eroded upper surface of the Patuxent over- lain by Sunderland deposits, Belt Line cut near Charles Street, Baltimore: Clty oad iacinscdawescaes tees toes tee eee ees Fig. 2.—View showing Patuxent-Arundel contact south shore of Spring Gardens, the probable locality where Tyson collected the historic Johns Hopkins cycad stump, Baltimore County.... Fig. 1—View showing indurated ledges in the Patuxent formation, W Street near 12th Street, Washington, D. C................. Fig. 2—View showing flooded iron mine in the Arundel formation near Muirkirk, Prince George’s County...............cseeeee Fig. 1—View showing the Patuxent-Arundel contact in Belt Line cut near the eastern boundary of Baltimore City.............. Fig. 2.—View showing erosion of old iron mine in the Arundel formation, Schoolhouse Hill, Baltimore County............... Fig. 1—View showing erosion of Arundel clays, Hartke Iron Mine near Hanover, Howard County.........c.c cece eee en rece neeee Fig. 2—View showing Reynolds Iron Mine in the Arundel forma- tion 1 mile south of Hanover, Anne Arundel County........... Near view of layers of carbonate of iron nodules in the Arundel clays, Reynolds Iron Mine, 1 mile south of Hanover, Anne Arundel County «icccaxivs oi oes cds pees see Leone ee Hem ees Fig. 1.—View showing Patapsco sands overlying Arundel clays, Cedar Hill Mine, Timberneck, 1 mile southwest of Hanover.... Fig. 2.—View showing ledges of indurated sand in the Patapsco formation which is overlain by greensands of the Aquia Eocene in cut of R. F. & P. R. R. near Aquia Creek, Virginia........... Fig. 1—View showing massive variegated clay of the Patapsco formation, near Hawkins Point, Anne Arundel County........ Fig. 2.—View showing Patapsco sands and clays overlain by Pleis- tocene sands, B. & O. R. R. cut, Rosedale Hill, Baltimore County 23 32 32 40 40 60 60 64 64 68 68 72 80 84 84 88 88 16 ILLUSTRATIONS PLATE FACING PAGE XI-XIX. Dinosauria .......... 0... cece eee eee eee ieshea lenles Risniae to nteuens atau 510-518 XX. Dinosauria-Crocodilia ......... ccc ccc cece eee ene en eeneeeeee 519 XXL: (MoMUsca) 06 cia savleu tie baler sien erated tacks sme es dae gets ee wees 520 XXIT-XLE, Pteridophyta. s..i656 sas .ccee seared o4 dae bane eee Se Os TEE OS 521-540 XLIT-LVIIL. Cycadophyte ........ ccc ccc cece cent ence eeeneeee 541-557 LIX-LXXVIII. Gymmnosperme ........... ccc cece eee cence reece 558-577 LXXIX, LXXX. Monocotyledone ........ ccc cece ccc cece e ee eeeee 578, 579 LXXXI-XCVII. Dicotyledone ...:............ faa ala alate eceseseuege Sead oe 580-596 FIGURE PAGE 1. Sketch map of the world showing the approximate location of out- crops containing Lower Cretaceous plants...........cceeeeeeereee 150 2. Restoration of a frond of Schizeopsis americana Berry, about four- fifths natural. ‘S126. 6.23 sesso wes vs eye et eaieed bead a ven eb anes eae 218 3. Sketch map of the world showing the Mesozoic and existing distri- bution of the family Matoniaces............. ccc ccc wee a eee ee eaee 234 4. Restoration of Sagenopteris elliptica, about natural size............ 288 5. Transverse section of a partly emergent but still folded frond of Cycadeoidea ingens deeply embedded in ramentum, X 4........... 314 6. Sketch map of the world showing the approximate distribution of the . OXistinge Cy Cads! snA.cvoeas asiieacinegdin ss aie een wea sea aad e e Aeiwe ose 315 7. Restoration of an unexpanded bisporangiate strobilus of Cycadeoidea with some of the bracts removed, about one-fourth natural size.... 317 8. A. Radial longitudinal section of an ovulate strobilus of Cycadeoidea, somewhat reduced: iis scene cece s iaaeees Mens caieevese es eoeeses 318 B. Semi-diagrammatic longitudinal section of a bisporangiate stro- bilus of Cycadeoidea, about one-half natural size:................. 318 9. Two views of the type of Williamsonia virginiensis, one-half natural size Cafter Fontaine) 25.034 s0s is eee eoee ed wane ss ieee dees ck 319 10. Cuticle of Dioonites Buchianus viewed from within, X 385.......... 334 11. Cross-sections of fronds of Nilsonia densinerve. A, showing method of fossilization of specimen shown on Plate lvii, Fig. 1, natural size. B, diagrammatic cross-section of specimen shown on Plate lviii, Fig. My. AVQCUTAL SLO isc: '5 5 veige SE“. sytcee aes ausshisries Garten Sse estbauave sa Sue wnva a WOW « GraNATES 363 12. Sketch map of the world showing the approximate distribution of theexistinge Taxacem: as« sees dee 008 ahead aati ea wale 8k weeds Bie ea dear, 376 13. View showing the whole midrib and the cuticle of one-half the lamina of Cephalotaxopsis magnifolia, K110....... ccc cece w eee eens 378 14. View of a preparation of the epidermis of Frenelopsis ramosissima.. 423 15. Sketch map of the world showing the segregation of the existing Actinostrobine and the Mesozoic occurrences of Brendlopsta and WIdGTINGLONNES: oeccacn Stems cu stesso kde eBid aire Were 5 EE ee we 427 PREFACE The present volume is the fourth of a series of reports dealing with the systematic geology and paleontology of Maryland, the Eocene, Mio- cene, and Plio-Pleistocene deposits having already been fully described. The Lower Cretaceous deposits which form the subject-matter of the present volume are more fully developed in the Maryland-Virginia area than anywhere else in eastern North America and the Maryland section is the type for the whole Atlantic coastal plain. Similarly the faunas and floras of the Lower Cretaceous are much more fully represented than elsewhere in this general region, the flora in particular being the richest known flora of this age. The vertebrate fauna of the Arundel formation collected by Mr. John B. Hatcher and studied by the late Professor O. C. Marsh of Yale Uni- versity is of interest, since it is the only Lower Cretaceous vertebrate fauna known east of the Mississippi River, and it was upon these materials that Professor Marsh based his opinion that the Potomac was of late Jurassic age. This fauna has been thoroughly revised and elaborated in the light of additional collections by Professor R. 8. Lull of the same institution. His results are in agreement with the evidence of the fossil plants that these deposits are of Lower Cretaceous age. The invertebrate faunas, while meagre and poorly preserved, are of great interest, since they constitute the only known representation in eastern North America of the estuarine and fluviatile invertebrate life of the Lower Cretaceous. This fauna has been described by Professor W. B. Clark of the Johns Hopkins University. The fossil floras have been restudied by Mr. EH. W. Berry of the Johns Hopkins University. The difficulties in the way of an adequate study of the Potomac flora are very great. The material, with the exception of silicified wood, lignite, and the silicified trunks of Cycadeoidea, is all 18 PREFACE in the form of impressions, and these, while abundant and diverse, are with some notable exceptions poorly preserved as well as fragmentary, much more so than the diagrammatic figures built up from various frag- ments by previous students would lead one to suspect. The silicified wood and lignite, while abundant, has for the most part undergone so much decay before fossilization that the bulk of it is worthless. In addition to the sections made by Dr. F. H. Knowlton and forming the basis of his paper on the Fossil Wood and Lignite of the Potomac, a large number of sections have been studied by Mr. Berry, most of which proved unidentifiable, because of the extreme stage of decay before fossilization. The most perfectly preserved show only the comparatively unimportant features of the secondary wood. The petrified Cycadeoidea trunks were also found to be poorly preserved, constituting in this respect a remarkable contrast with those from the Black Hills area and elsewhere. The necessity of some sort of systematic treatment of the maze of described forms in the literature of the Potomac which would enable the geologist or the botanist to obtain some idea of the flora has long been felt. The pre-existing multiplicity of species has made it necessary to retain a number of extremely doubtful forms. Many have, however, disappeared by reduction to synonymy, and some basis for the correlation of a number of genera with their living representatives has become apparent during the progress of the work. Certain important forms known only from the continuation of the Maryland deposits in the Virginia area have been included, while others *upon which no new light could be shed have been omitted. These latter will be discussed on a subsequent occasion in a work devoted to the Virginia area and in course of preparation for the Geological Survey of that state. Mr. Berry is indebted to various friends and colleagues both at home and abroad for assistance during the progress of the work. He is under especial obligations to the U. 8. National Museum and Dr. F. H. Knowlton for facilities in the study of the large Lower Cretaceous collections of that institution as well as for many other courtesies. The British Museum through Dr. A. Smith Woodward rendered invaluable PREFACE 19 assistance in contributing a large number of English Wealden plants for comparison, and Professor Yokoyama of Tokio kindly forwarded Japanese material of Onychiopsis. Dr. Albert Mann of the Department of Agriculture and Doctors F. H. Blodgett and W. Ralph Jones have con- tributed photo-micrographs or camera lucida drawings. The U. S. Geological Survey has cooperated in furnishing a large number of the illustrations and in various other ways. Finally any student of Lower Cretaceous floras must acknowledge his great indebtedness to previous workers who have contributed to our knowledge of these floras, more especially to Professor Seward in England, the late Marquis Saporta in Portugal, the late Professor Os- wald Heer in the Arctic regions, and Professors Ward and Fontaine in this country. THE LOWER CRETACEOUS DEPOSITS OF MARYLAND BY WILLIAM BULLOCK CLARK ARTHUR B. BIBBINS * AND EDWARD W. BERRY MARYLAND GEOLOGICAL SURVE'r. MAP SHOWING THE DISTRIBUTION OF THE LOWER CRETACEOUS FORMATIONS MARYLAND MARYLAND GEOLOGICAL SURVEY WM. BULLOCK CLARK, Strate Geotoscist SCALE One inch equals five miles 1: 812,500 1911 LEGEND Patapseo Formation POTOMAG aa Arundel Formation GROUP 5 ml : ie | Patuxent Formation x Fossil Localities I-xxml Location of Sections NOTE,—When locations selected for sections contain fossils l.-} =. ‘i =a “Aaa the asterisk is not added to the Roman numerals \ fe a } \ ) Se ) tS Ae WN ZN Se if B= of ‘ \Sa =~ a Le y PR te iis es YI sete SSK hg mall ~ Nuriiias ’ 2! : | 7, Ai LOWER CRETACEOUS, PLATE I. Stewartetown JTION OF THE TACEOUS IONS Re Shaweville T-— ‘f Blackhiors AND Fone tump Os Ph bUNeck \ , J f Town Pre _—~ Point SOnKM Mi Le \ ICAL SURVEY State GEoLoacist . FISHING BATTERY LN Rocky ft VN Spey i > Ti 7e miles Howell Pt Cent | Be tterton ~ sg <5 BA ‘ 2 J a a aa Pretoria fe \ a ID (CHEST. (\RR Lambson Blacks f i ~ é ey a ae ys V Rickert PE — Robins Pt lation © ETON Kennedy / and Nqtlepbron,_WA: Lower Island Pr- Menton le \ (Srnidhy? POTOMAC Tres © River ae re Mandys Pt a ay oe PE | 2 fs bate. \ i os | Pootes Lutleriown_ 8" | } ation 4. RIE Aes pie a se freatensie | GROUP Y u Rriorton l Balliston Pt | ~ SX \ y = " f, = nation ae / Telit a Z / / | b es 7 orca | i nae ‘ y | \ -fieor fet’ Comers ‘arners proud aly Yah | / iUIchp sac Beciedy pun . turk Me | A \ ections f Rs : ; RANOE LION opr HOWARD y Peters Copners) ‘North Pr if = S, Duhamel tions contain fossils SeonT sMatewooo \ 1 numerals Sevenroor Nou LW SwanPt sha ‘Mind Pr Ri eH SA 1 a bu) y Spanan \ ‘ wri Cee {? Aa = + 4 a Os . \ ( e Grays inn Pi oy ~ i 8 ae £ 7 Folton A lo. on PPS tn Lata Dy, fovea £2 | Clark Cornery | yA . Pe SrdonFr oo a / _tantgyille p e wf JF q At Wn, - L Le e DL \erowgavitle las WHE! ¥ / 4 7 { Me Vibes p eee ( \ Jadgksony, ( in Seen Ss ~ a ac < G penter | to} NOTE.—When locations selected for sections contain fossils the asterisk is not added to the Roman numerals \ Meadows: | UP x y . | Oxonhiy [i te | yr ee = Caanp Springs ( | } re fe Raf) aN An Ly i 2 Wopdyard\ / a ~_— | iJ [ \ Seg M RN! es \ wreeramo iw, aS ee K > a 7 sr Yo hex x y? X far lhorg ie \ prose \ Drury a mnsvlvarta June) XS 3 \ PSEevri \ __~ (Lalve ESA | \Croom Station 2 /ACKSO Loo Greenoel | Bristol Purn \ ( \ HKeyldree \Elvaton Got” ga PRB ape a at ge Us = oy Greenbury Pt Oo \ J on Wer |: ER olly Pr j \ So E W7,6 i £ o rn HITNEY NX : \, SEVENFOor KNOLL LH \Bedtoat West x cn Srilvlaoe “HackettPt Bas Fodge | SHARPS 1.1. (izhere® | 2 ) VRS CNES SS ee f\ oe Sonnsonfille D North Pt 2 C v) ) 8 o\ Athol Sh ont y /\ ~- ay NS a4 es scted for sections contain fossils 3 X% oN SMELL K j a ae ENG] aeoeragutinons to the Roman numerals EAGT Na VT co PG 1, Sevenroornvouen Lf | oN q zi ) S A f - i 4 > x y 5 \ of “7 Th 2G é Li OL : Bey Ay Ae HalpR(~ Y LF = a i if PL a ra he 5 rdpitGion SY eee Z i] x © \ Woodhie Ne i < : Cockey!. 3 Bo, oe e, et ny DY MWh ona er | \ ~ \3/ YC Ly) a ms st —4 : ; “ aa OY / TeX L? e \8 g Dae Sis N CR : “ap ) ; Re ilg hk } op bi ah i Lar ae Me : 5 likin) ‘ Brights S \ ty . eh ue oe . a AB AY on the Bay { ) agu \ \/ : d x } 77) < } s eI LA thomas Pt ¥ \ Hardles| J \ ‘ ras i ee it Ls - = ; 4 Dodd Birdev Nr \ SS eee aR Gallownys. 1p Shaul = Sane at Be eee A eee AS NY ftion ) | o : aA st = ae SS ee ee ee ee ee « : i aN t ‘ } , RS | ‘ . = Meadors UPPER aS) on ‘ \ ir L 1 Wise \ + Sukew i ee Giibse \Prucy | 5, A " ; wad 4 \ ~~ > ‘all PY / . ensvlvudtye June) A WracbAda. ~ hide % Brestyl = Parm ( aaell AN q \ \ i Le } a D : Oxonhil [\* I one Kr LH : A fo — dWopdyard’ Greenoc = . SA Gap springs ( : be 2 , Ly Yh \ 5 Ae ee Y 6 ; Hrs: MiLalve HE SARE Ay, \ edrteS | . bee Jigs fovom Station Wey gehts rn vi . To ew : | AcKsone4 . f \ ilbvede >> | Fi ae Cinton ) 4 {- cr 9 Act Valtian Lows Lg med _ as Jewell Pa h I = fA osaryville rites “<\ \ Ao Ry ( 4 Tesi Pippett Pi Re NS a Ss peyona ce i} Coe “3 : ENA fp ; fy oa ct SID : <{ pe ) Reform Schoot ~Kiranonaced A, ai Staso Xe, len \ = Be \ 4 : SATalbert 3) = 2 i eS \ id P+. nly oe CS ESO Reales J | 7 Li . ‘ % ernon ‘ j wy : ae ‘ 2 Tghman t ‘ Mei cena “ar > § i ie ) ay tania oh siarmony, vata) 1 } : oro . 4 es N \ehyneyvites? Cha ‘ \ Vcore Le f ms ye \ P_ Beas \ peer 8 // Ss 1 ey, 7 Band 7e\ Busha < ( LBirbyink é > aN G xe f yo ~ Ps : ¥ v % a N , C af. | 2 i. fd : Bhs \ Blade } harpervitle , \ Ve ee wilire Lawore : eo) Sunderla Poplags \ Se ae a aheokg t ay ‘oynsh = SS —— = a2 AS Se Be | nate $@e.ont ay x . / ; ; r \ Bleckialnut = oy! gl Sears iter Riewenpor. ise a A es se ‘ TO} \ ee Utawo ( lorsehbau a fon i . _ \ an ‘y y I ™ gs ay bie ial ; i ee CS pain oe N i { x * Lee 276 Y z \ SHARPS 10.1.6. oO 4 = An ! > Untinglow!, \ Island \4 \ | ‘qokPt 2 Ghiore Pts, C ee ee Se os | tae “) A ee 3, en é ye ~ a ee A : Sate § pO PCR, S\N cine / ee | NS, at (3) tere Ne Tenant) Lf ao 1M SN py PRE | | Sama neon w | ELE Necemtte Nn sensei PS 7to8 E < TIN \ J Gallant f | whan f tf Res loyds cere Be x as P “\ et 7 tins ~ : % i o > \ NY : = ‘ : bi ~ ~~ } ( } * ; . : Ey wy ~~ i SS jatdpit | ~7~ ie ia | f x - ys / io Malcolm ~s \. sey : (\iisce* | eel] o, r 5 b OVS} [s \ ~ i ~ J | ” \ t { / | % Hh : r cv ! y INP ez \ Bo 4 h , lanes, C! A 4 S et ~K " “Hf ial VA H tee ( / e \ x Se agen JK ol ¢ § woot Seen » Seated 2 | f s ar Se a \< \ bes G fo ay -* ps vp H : BY : / Hills Pt. i 4 at é fc “SRA A ( \ ie sey ChlkistaRuck // ; q Mee | | | * pasa Da James, 4 ie ry oo \\ fe cs a | Ne a REEY ured creek “When Cotith Baltimore. Ml. THE LOWER CRETACEOUS DEPOSITS OF MARYLAND BY WM. BULLOCK CLARK, ARTHUR B. BIBBINS, AND EDWARD W. BERRY INTRODUCTION A knowledge of the Lower Cretaceous deposits of Maryland can only be secured through an understanding of the physiography and geology of the broad province of which the State of Maryland forms a part. The physical features which characterize this area may be traced for varying distances into adjoining regions, some being recognized as far as the New England coast on the north, and others as far as the Gulf Region on the south. THE PHYSIOGRAPHY The region here considered forms a portion of the Atlantic slope, which stretches from the crest of the Alleghanies to the sea, and which is divided into three more or less sharply defined regions known as the Coastal Plain, the Piedmont Plateau, and the Appalachian Region. These three districts follow the Atlantic border of the United States in three belts of varying width from New England southward to: the Gulf. Maryland is, therefore, closely related in its physiographic fea- tures to the States which lie to the north and south of it, while its central location on the Atlantic border renders it perhaps the most char- acteristic in this broad tract. In crossing the three districts from the ocean border the country rises at first gradually, and then more rapidly, until it culminates in the highlands of the western portion of the State. 24 THE Lowzr Cretaczous Dzpostrs or MARYLAND The Coastal Plain is the name applied to the low and partially sub- merged surface of varying width extending from Cape Cod southward through Florida, and confined between the Piedmont Plateau on the west and the margin of the continental shelf on the east. The line of demarkation between the Coastal Plain and the Piedmont Plateau is sinuous and ill-defined, for the one passes over into the other oftentimes with insensible topographic gradations, although the origin of the two districts is quite different. A convenient, although somewhat arbitrary boundary between the two ‘regions in the Maryland area is furnished by the Baltimore and Ohio Railroad in its extension from Wilmington southwestward through Baltimore to Washington. The eastern limit of the Coastal Plain is at the edge of the continental shelf. This is located about 100 miles off shore at a depth of 100 fathoms beneath the surface of the Atlantic Ocean. It is in reality the submerged border of the North American continent, which extends seaward with a gently sloping surface to the 100-fathom line. At this point there is a rapid descent to a depth of 3000 fathoms, where the continental rise gives place to the oceanic abyss. The Coastal Plain, therefore, falls naturally into two divisions, a sub- merged or submarine division and an emerged or subaérial division. The seashore is the boundary line which separates them. This line of de- markation, although apparently fixed, is in reality very changeable, for during the past geologic ages it has migrated back and forth across the Coastal Plain, at one time occupying a position well over on the Pied- mont Plateau, and at another far out at sea. At the present time there is reason to believe that the sea is encroaching on the, land by the slow subsidence of the latter, but a few generations of men is too short a period in which to measure this change. The subaérial division is itself separable in Maryland into the Eastern Shore and the Western Shore. These terms, although first introduced to designate the land masses on either side of Chesapeake Bay, are in reality expressive of a fundamental contrast in the topography of the Coastal Plain. ‘This difference gives rise to an Hastern Shore and a Western Shore type of topography. Chesapeake Bay and Elk River sepa- MarYLAND GEOLOGICAL SURVEY 25 rate the two. Areas showing the Eastern Shore type are found along the margin of the Western Shore at intervals as far south as Herring Bay, and again from Point Lookout northwestward along the margin of the Potomac River. On the other hand, an outlier of the Western Shore type of topography is found at Grays Hill, in Cecil County,’ at the northern margin of the Hastern Shore. The Eastern Shore type of topography consists of flat, low, and almost featureless plains, while the Western Shore is a rolling upland, attaining four times the elevation of the former, and resembling the topography of the Piedmont Plateau much more than. that of the typical Eastern Shore. It will be seen later that these two topographic types, which at once strike the eye of the physiographer as being distinctive features, are in reality not as simple as they first appear, but are built up of a complex system of terraces dissected by drainage lines. The Coastal Plain of Maryland, with which most of the State of Delaware is naturally included, is separated from that of New Jersey by the Delaware River and Delaware Bay, and from that of Virginia by the Potomac River, but these drainage ways afford no barriers to the Coastal Plain topography, for the same types with their systems of ter- races exist in New Jersey and Virginia as well as in Maryland. The Chesapeake Bay, which runs the length of the Coastal Plain, drains both shores. From the Western Shore it receives a number of large tributaries which are in the process of developing a dendritic type of drainage, and which have cut far deeper channels than have the rivers of the Eastern Shore. If attention is now turned to the character of the shore-line, it will be seen that along Chesapeake Bay it is extremely broken and sinuous. A straight shore-line is the exception, and in only one place, from Herring Bay southward to Drum Point, does it become a prominent feature. These two classes of shore correspond to two types of coast. Where the shore is sinuous and broken, it is found that the coast is low or marshy, but where the shore-line is straight, as from ‘Herring Bay southward to Drum Point, the coast is high and rugged, as in the famous Calvert Cliffs which rise to a height of 100 feet or more above the Bay. The shore of the Atlantic Ocean is composed of a 26 Tue Lower Creraceous Deposits or MARYLAND long line of barrier. beaches which have been thrown up by the waves and enclose behind them lagoons flushed by streams which drain the seaward slope of the Hastern Shore. It was stated in the early part of this chapter that the topography of the Coastal Plain is in reality more complex than at first appears, and that this complexity is due to a system of terraces out of which the region is constructed. The subaérial division of the Coastal Plain con- tains four distinct terraces and part of another, while the submarine contains one only. This makes for the Coastal Plain, as a whole, a group of five terraces. These terraces, beginning with the highest, are known by the names of Lafayette, Sunderland, Wicomico, Talbot, and Recent. All five of the subaérial terraces are found on the Western Shore, while only three of them occur on the Eastern Shore. These terraces wrap about each other in concentric arrangement, and are de- veloped one above another in order of their age, the oldest standing topographically highest. THE GEOLOGY The area of low land and shallow sea floor which borders the Piedmont Plateau on the east and passes with constantly decreasing elevation east- ward to the margin of the continental shelf has been described under the name of the Coastal Plain. It is made up of geological formations of late Mesozoic and Cenozoic age. These later formations stand in marked contrast to the older strata to the westward, in that they have been but slightly changed since they were deposited. Laid down one above another upon the eastern flank of the Piedmont Plateau, when the sea occupied the present area of the Coastal Plain, these later beds form a series of thin sheets that are inclined at low angles seaward, so that successively later formations are encountered in passing from the inland border of the region toward the coast. Oscillation of the sea floor, with some variation both in the angle and direction of tilting, went on, however, during the period of Coastal Plain deposition. As a result the stratigraphic relations of these formations, which have gen- MARYLAND GEOLOGICAL SURVEY 27 erally been held to be of the simplest character, possess in reality much complexity along their western margins, and it is not uncommon to find that intermediate members of the series are lacking, as the result of transgression, so that the discrimination of the different horizons, in the absence of fossils, often requires the utmost care. The Coastal Plain sediments were laid down after a long break in time following the deposition of the red sandstones and shales (Newark formation) of late Triassic age, which overlie the crystalline rocks of the western division of the Piedmont Plateau, and complete the sequence of geological formations found represented in Maryland and Delaware. From the. time deposition opened in the coastal region during early Cretaceous time to the present, constant sedimentation has apparently been going on, notwithstanding the fact that frequent unconformities appear along the landward margins of the different formations. The formations consist of the following: ForRMATIONS OF THE COASTAL PLAIN. Cenozoic. Quaternary. Recent. Pleistocene.............- TAD Ob s¢ 4 scence: Some Wicomico.......... : = Columbia Group. Sunderland......... Tertiary. Pliocene (?) ..........4. Lafayette. Mi0Cene wiu.6 «aise se eee es eee St. Mary’s.......... Choptank...........$ == Chesapeake Group. Calvert..........048 $ BOONE: vse cc eee sities a eee sie Nanjemoy Sisiacoiieteledss \ = Pamunkey Group: AQUIAE siae scored awe Mesozoic. Cretaceous. Upper Cretaceous........ Rancocas. : Monmouth. Matawan. Magothy. Raritan. Lower Cretaceous........ Patapsco........... Arundel...........- == Potomac Group. Patuxent........... 28 Tr Lower Cretaceous Deposits or MARYLAND CRETACEOUS Lower Cretaceous The Lower Cretaceous is represented by the Potomac Group, which consists of the Patuxent, Arundel, and Patapsco formations, deposits laid down under estuarine and fluviatile conditions. The three forma- tions have only been recognized in their full development in Maryland, the lowermost Patuxent formation not being found to the north of Maryland but extending southward as the basal division of the Coastal Plain series through the south Atlantic States to eastern Alabama, while the uppermost Patapsco formation extends northward into Pennsylvania and disappears southward in central Virginia. The Arundel formation has been recognized in Maryland alone. The three formations are unconformable to each other and the under- lying and overlying formations. They consist chiefly of sands and clays, the former frequently arkosic, while gravel beds are found at certain points where the shoreward accumulations are still preserved. The deposits of the Patuxent formation consist mainly of sand, often arkosic, and at times argillaceous, while clay beds at times appear. The Arundel formation consists largely of clays, frequently dark colored, and affording in places large amounts of nodular carbonate of iron. At times the deposits are very carbonaceous. The Patapsco materials consist largely of highly colored and variegated clays which grade over into lighter colored sandy clays and also at times into sands. The organic remains consist largely of fossil plants although the Arundel formation has afforded representatives of several orders of Reptilia together with a few invertebrate fossils. The fossil plants in the Patuxent and Arundel formations consist chiefly of ferns, cycads, and conifers, while the Patapsco formation contains a considerable rep- resentation of dicotyledonous types. Messrs. Berry and Lull, who have studied the plant and animal remains regard them as characteristic of the Lower Cretaceous. The fossil plants of the Patuxent and Arundel are strongly Neocomian-Barremian in character, while those of the Patapsco are distinctly Albian. . MARYLAND GEOLOGICAL SURVEY 29 The total average thickness of the Lower Cretaceous formations in Maryland is between 600 and 700 feet, and they show an average dip of about 40 feet in the mile to the southeast. Upper Cretaceous The deposits referred to the Upper Cretaceous comprise the Raritan, Magothy, Matawan, Monmouth, and Rancocas formations. The two lower formations are estuarine and fluviatile in origin, while the over- lying formations are distinctly marine. All of these formations can be traced to the northward into Delaware and New Jersey, where they attain an even larger development than in Maryland. To the southward they are gradually overlapped, one after the other, by the Tertiary formations and are unknown in Virginia. Similar deposits are found in North Carolina and the States which lie to the south of it but are known under other formational names. The four upper formations form an apparently conformable series testing unconformably upon the Raritan formation, which in turn over- lies the Patapsco formation unconformably. A slight unconformity may perhaps exist between the Magothy and the Matawan, although a fuller study of the relation of these formations indicates that they are prob- ably conformable over the greater portion of the area of outcrop. The deposits consist chiefly of sands and clays, with some gravels in the two lower formations, while the three higher formations consist more par- ticularly of clays and sands, the latter often somewhat glauconitic, although much less so than Similar deposits in New Jersey. The Rari- tan formation consists chiefly of thick-bedded and light-colored sands with some gravels. Clays generally light in color occur in the lower portion of the formation. The Magothy formation is made up of sands and clays that change rapidly both horizontally and vertically, finely laminated clays with sand layers and more or less carbonaceous often appearing. The Matawan formation is composed of micaceous, sandy clays somewhat more sandy at times in the upper portion and more argillaceous in the lower portion of the formation. The Monmouth formation consists of reddish and pinkish sands more or less glauconitic 30 Tue Lower Cretaceous Deposits oF MARYLAND in character. The Rancocas formation, which outcrops in Delaware near the Maryland line, consists of greensand marls which are fre- quently highly calcareous. The organic remains consist chiefly of fossil plants in the Raritan and Magothy formations, and of fossil invertebrates in the Matawan, Monmouth, and Rancocas formations. The flora consists largely of dico- tyledonous types those forms found in the Raritan formation being dis- tinctly Cenomanian in character while those of the Magothy are ap- parently Turonian in age, which is apparently also the age of the Matawan invertebrates. The Monmouth fauna, corresponding to the Ripley fauna of the Gulf, is universally regarded as of Senonian age, while the overlying Rancocas fauna has been referred to the Danian. The total average thickness of the Upper Cretaceous formations of Maryland is about 400 feet. They show a dip of from 20 to 35 feet in the mile to the southeast. TERTIARY Eocene The Eocene is represented by the Pamunkey Group, which consists of the Aquia and Nanjemoy formations. The deposits are of marine origin and comprise part of a geologic province embracing Virginia, Maryland, and Delaware. The two formations constitute a conformable series which overlies the Upper Cretaceous deposits in Maryland unconformably while in Virginia it has transgressed the latter and is found overlying the Lower OCre- taceous strata unconformably. The deposits consist chiefly of green- sands which are often calcareous in the Aquia formation and argillaceous in the Nanjemoy formation. The fossils consist mainly of animal remains and comprise an ex- tensive fauna, embracing particularly the group of Mollusca and Anthozoa, which shows a faunal relationship with the Wileox and probably with the lower Claiborne beds of the Gulf. The total thickness of the Eocene deposits in Maryland is about 225 MarYLAND GEOLOGICAL SURVEY 31 feet, and they show an average dip of 124 feet in the mile to the southeast. Miocene The Miocene deposits of Maryland are represented by the Chesapeake . Group, which is made up of the Calvert, Choptank, and St. Mary’s formations.t These formations are of marine origin. They attain a very extensive development in the drainage basin of Chesapeake Bay, both in Maryland and Virginia, from which area they can be traced southward into North Carolina and northward into Delaware and New Jersey. To the south of the Hatteras axis the conditions change materially, and other formations presenting faunal affinities more or less close are found. The several formations comprising the Miocene are apparently slightly unconformable to each other, although this unconformity is oftentimes not apparent, the Choptank in some areas being apparently conformable to the Calvert, while the St. Mary’s seemingly presents the same rela- tions to the Choptank. The deposits of the Chesapeake Group consist largely of sands, clays, and marls. The Calvert is in part sandy and in part clayey, with extensive deposits of diatomaceous earth in the lower or Fairhaven member, and numerous marl beds packed with mol- luscan shell remains in the upper or Plum Point member. The Chop- tank formation is essentially sandy, although clays and marls also occur. The St. Mary’s formation is decidedly clayey with sands or sandy clays, the latter typically greenish-blue in color and often containing large quantities of fossils. The organic remains consist largely of fossil invertebrates, by far the most common group being the mollusca. Diatoms are very common, and remains of land plants are not rare in the basal strata, while corals, bryozoans, and echinoderms are not infrequent. Many cetacean forms have been found at some localities. The thickness of the Miocene deposits is between 450 and 500 feet, and the strata have an average dip of 10 feet in the mile to the southeast. + Another formation, the Yorktown, occurs at the summit of the Chesapeake Group in Virginia and North Carolina. 3 32 Tuer Lower Cretaceous Deposits or MarYLAND Pliocene (?) The supposed Pliocene is represented by the Lafayette formation which has been considered as extending from the Gulf along the Atlantic border region as far northward as Pennsylvania, where the last remnants are found. The Lafayette formation is chiefly developed as a terrace _ lying irregularly and unconformably on whatever older formation chances : to be beneath it whether along the margin of the Piedmont Plateau or the Coastal Plain. Few fossils have been found in the Lafayette, and those not sufficiently distinctive to determine its age. We simply know that it is younger than the latest Miocene on which it rests and older than the oldest Pleistocene beds found in its immediate vicinity. It may be either Ter- tiary or early Quaternary in age, although most authors hitherto have regarded it as probably Pliocene in age. Doubtless materials of very different ages have been referred by various students to the Lafayette. The type section in Lafayette County, Mississippi, has recently been shown to be of Hocene age. The materials comprising the Lafayette formation consist of clay, loam, sand, and gravel which are often highly ferruginous, the iron being often present in the deposits in sufficient amount to act as a cement. These materials are generally very imperfectly sorted. The deposits rarely exceed 50 feet in thickness, while the southeasterly dip is only a few feet in the mile. QUATERNARY Pleistocene The Pleistocene deposits consist of a series of surficial materials known under the name of the Columbia Group, which has been divided in Maryland and adjacent States into the Sunderland, Wicomico, and Talbot formations. They consist mainly of a series of terraces which wrap about the Lafayette and the lower portions of the older formations, and hence extend as fluviatile deposits up the stream courses. 1 Berry, Journ. Geol., vol. xix, 1911, pp. 249-256. MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE I! Fic. I.—VIEW SHOWING BASAL CONGLOMERATE OF THE PATUXENT OVERLYING THE PIEDMONT CRYSTALLINES AT ROLAND PARK, BALTIMORE CITY. Fic, 2,—VIEW SHOWING PATUXENT ARKOSIC SANDS AND GRAVEL IN B. & O, R. R. CUT AT SAVAGE, ANNE ARUNDEL COUNTY. MARYLAND GEOLOGICAL SURVEY 33 Fossils have been found particularly in the latest, or Talbot forma- tion, where extensive shell beds of estuarine and marine origin are known. Fossil plants have been found in all the formations. Their general similarity has made it impossible to establish distinctive floras as a basis for the correlation of the several formations, which has been based mainly on physiographic grounds. The materials consist of clay, loam, sand; gravel, peat, and ice-borne boulders. These do not as a rule occur in very definite beds, but grade into each other both vertically and horizontally. The coarser materials are often cross-bedded, and are for the most part distinctive over the lower portion of each of the formations, while the finer materials, par- ticularly the loam, are commonly found in the upper part of the forma- tions, although these conditions are by no means universal. Each of the formations rarely exceeds 25 or 30 feet in thickness, although under exceptional conditions a thickness of two or three times that amount occurs. Recent The Recent deposits embrace chiefly those being laid down to-day over the submarine portion of the Coastal Plain, and along the various estu- aries and streams. To these must also be added such terrestrial deposits as talus, wind-blown sand, and humus. In short, all deposits which are being formed under water or on the land by natural agencies belong to this division of geological time. The Recent terrace now in process of formation along the ocean shore-line and in the bays and estuaries is the most significant of these deposits, and is the latest of the series of terrace formations which began with the Lafayette, the remnants of which to-day occupy the highest levels of the Coastal Plain, and which has been followed in turn by the Sunderland, Wicomico, and Talbot. - A deposit of almost universal distribution in this climate is the humus or vegetable mold, which being mixed with the weathered surface of the underlying rocks forms our agricultural soils. The intimate relation- ship therefore of the soils and underlying geological formations is evi- dent. « 34 Tue Lower Cretaceous Drerosirs or MARYLAND Other accumulations in water and on land are going on about us all the time, and with those already described represent the formations of Recent time. HISTORICAL REVIEW The more detailed and specific discussions of the Potomac Group and its contained fossils, as is usually the case, were preceded by a long period during which the geological and lithological relations chiefly at- tracted attention, and this in turn was preceded by a still longer period during which the subjects were still more general, and only passing reference was made to the series of strata since designated the Potomac Group. The earliest definite reference to rocks of this age is contained in two papers by B. H. Latrobe, the first of which dates back to 1799 and refers to the use of “ Rappahannoc freestone ” in the construction of the lighthouse at Cape Henry. The second paper, published in 1809, de- scribes this rock and its uses, and mentions the presence of the contained wood and lignite from the vicinity of Fredericksburg, Virginia. The paper by John Finch, read before the Philadelphia Academy in 1823, and so often cited in historical discussions of Coastal Plain geology, mentions the organic remains in the clay underlying the diluvial gravel at Washington, and although not altogether unequivocal probably refers to Potomac strata. Morton’s paper of 1829, which was based on the notes of Vanuxem, describes the lignite and charred wood of these rocks, which they include in their “ Secondary formation.” The first intimation of the wide extent of the Potomac formations is contained in an early report of Edward Hitchcock, published in 1833, in which he mentions the probable distribution of deposits of this age from Cape Cod to the Gulf of Mexico. In a paper published by Thomas G. Clemson in 1835 there is a good description of the Potomac material near Fredericksburg with its fossil wood and lignites, and with the first reference to impressions of plants which he says are finely preserved in blue argillaceous fissile beds from six inches to a foot in thickness. MarYLAND GEOLOGICAL SURVEY 35 Richard C. Taylor, in a paper immediately following that of Mr. Clemson devotes six pages and a folded plate to the description and illustration of these plants, which he identified as Lycopodiolithes ? sp., Lepidodendron sp., Sphenopteris sp., Pecopteris ? sp., and Thuites ? sp., and which are the remains of Frenelopsis, Sphenolepis, Cladophlebis, etc. These he saw bore no relation to the plants from the Richmond coal field, which were attracting considerable attention at that time and he infers that the containing rocks are of Secondary age, perhaps co-eval with the oolites. The year 1835 also marks the beginning of the important series of reports on the geology of Virginia by William B. Rogers, State Geologist of that State, the first describing the Potomac sandstones along the “ Fall-line ” and mentioning the presence of silicified wood, lignite, and plant impressions. In his report for 1839 the same author traces his “ Sandstone formation ” as far south as Bollings Bridge on the Nottaway River in southern Virginia. In his next report, that for 1840, he desig- nates this formation the “Upper Secondary,” and traces its extent northward from Petersburg to the Potomac River. Later reports also frequently refer to these rocks, which he regarded as Upper Oolite in age. Richard C. Taylor returns to this subject in his work on the Statistics of Coal, published in 1848, and compares the organic remains to those from the Portland of southern England. With the appointment of Philip T. Tyson to be State Agricultural Chemist of Maryland, the latter State enters the literature. The map accompanying his first report enumerates twenty-four formations, of which the Cretaceous includes two, the first “a thick group of sands and clays of various colors.” “In some localities it abounds in lignite derived from coniferous plants.” “The bluish-gray varieties derive their color from the carbonaceous remains of plants”; the second, or Iron-ore clays, “a series of beds of fine gray and lead-colored clays containing several courses of carbonate of iron in flattened masses and nodules.” “ The color of these clays is due to carbonaceous matter.” Tyson early discovered a saurian tooth in the latter beds, which was described under the generic name Astrodon by Christopher Johnston in 36 Tue Lower Cretaczous Deposirs oF MaryLAND 1859, and more fully described by Professor Joseph Leidy in 1865. From the same bed which yielded the tooth Tyson records “a new genus of - Cycas of large dimensions,” “ silicified coniferous wood,” and “ lignites (coniferous).” In his next report, published in 1862, Tyson discusses these iron-ore clays and says he is disposed to place them as low as the oolitic, which view is concurred in by Agassiz, to whom he had showed a photograph of the cycad trunk. Tyson found a number of these cycad trunks and sent pictures of them to various geologists. They are men- tioned by Professor Dana in the first edition of his Manual, with the comment that P. T. Tyson observes that they may be Upper Jurassic. One trunk was presented to Professor Dawson and is still at Montreal, another was presented to Professor Marsh and is now in the Yale College collection, while a third turned up recently at the South Carolina Col- lege at Columbia, probably a gift by Tyson to Professor Le Conte, who at that time was located at Columbia. The others were for a long time in the possession of the Maryland Academy of Sciences, which institution eventually turned them over to the Johns Hopkins University where they are at the present time. Professor Dawson sent one of Tyson’s photo- graphs to Carruthers, who refers to it in a postscript to his memoir “On Fossil Cycadean Stems from the Secondary Rocks of Britain,” pub- lished in 1870. Professor Cope in a paper read before the Philadelphia Academy in 1868, sketches the geology of the Cretaceous as developed from New Jersey to Virginia, mentioning the cycadaceous plants of Tyson, and also teferring to the clays along the Rappahannock from which Professor Uhler has obtained the “remains of some six species of plants, in beau- tiful preservation, of the order Cycadacee ?, Gnetacee, and Filices.” This was probably the Fredericksburg plant locality which afterward re- warded Professor Fontaine’s efforts with such a great variety of speci- mens. Professor Cope states that it is extremely probable that these Virginia beds are the continuation of those of Maryland and Alexandria, and he proceeds to sketch the conditions of deposition comparing them to the conditions which prevailed to the westward in Triassic times. He says further: “The age is therefore probably truly Wealden or Neo- comian.” MARYLAND GEOLOGICAL SURVEY 37 Among other “Geological Notes” presented to the Boston Society of Natural History in 1875 by W. B. Rogers is a paper “ On the Gravel and Cobblestone Deposits of Virginia and the Middle States,” in which he clearly distinguishes the surficial gravels of the Lafayette and Colum- bia from those of the older Potomac. “In the belt partially occupied by the surface deposit here referred to there is exposed another ‘group of strata with which, at first view, the sandy and argillaceous layers of this formation might readily be confounded. These are the silicious, argillaceous, and pebbly beds, which, underlying the Tertiary in Virginia, and the well-marked Cretaceous formation farther north, have, in the latter region, been regarded as belonging to the base of the Cretaceous series of the Atlantic States. In Virginia the formation consists typically of a rather coarse and sometimes pebbly sandstone, in which the grains of quartz and feldspar are feebly cemented by kaolin, derived from the decomposition of the latter, and of argillaceous and silicious clays vari- ously colored and more or less charged with vegetable remains, either silicified or in the condition of lignite. These constitute the group of beds designated in the Virginia geological reports as the Upper Second- ary sandstone, and referred by me long since (1842) to the upper part of the Jurassic series, corresponding probably to the Purbeck beds of British geologists. From the Potomac northward this group of deposits, as exposed in the deep railroad cuts between Washington and Baltimore and on to Wilmington, is made up of variegated, soft, argillaceous, and silicious beds, which, from the preponderance of ferruginous coloring toward the Delaware, has been called by Professor Booth the red clay formation. At a few points only toward the bottom of the deposit it brings to view a bed of the felspathic sand, or crumbling sandstone, above referred to. Traced transversely, it is seen to dip beneath the Cretaceous greensand at various points in New Jersey, Delaware, and Maryland, but in Virginia disappears in its eastward dip beneath the Eocene Ter- tiary. “How far we may consider this group of sediments in Maryland, Delaware, and New Jersey as merely a continuation of the Virginia for- mation above described can be determined only by further investigation. 38 Tue Lower Cretaczous Deposits or MaryLAND But the discovery in them at Baltimore, by Professor Tyson, of stumps of cycads would seem to bring them into near relation with the formation at Fredericksburg containing similar remains, and to favor their being referred, at least in part, to the horizon of the upper Jurassic rocks. Possibly we may find here a passage group analogous to the Wealden of British geology. Whatever may be the result of further discovery, it would seem to be premature at this time to assume the whole of these deposits from the Potomac northward as belonging to the Cretaceous series. “Where the Tertiary or Cretaceous rocks are present in this belt there is, of course, no danger of confounding the superficial gravel and cobble- stone deposit with the formation just described, but in their absence, which is usual in the river valleys, this deposit rests immediately on the broken and denuded surface of the Secondary, and by the inter- mixture of materials makes it more difficult to discriminate between them. . “ Excellent opportunities for observing the contact of the superficial deposit with the denuded and much older formation below are presented in the neighborhood of Washington, among which may be specially men- tioned the vertical cut at the extremity of Sixteenth street, at the base of the hill occupied by Columbian College, and also the continuation of Fourteenth street, ascending the same hill. At the former locality the crumbling felspathic sandstone, or slightly adhering sand, is exposed to a height of about 35 feet, with a very gentle eastern dip, and having the color, composition, and diagonal bedding characteristic of the Fredericks- burg and Aquia Creek sandstone. The gravel and cobblestone deposit lying upon it descends with the slope of the hill to the general plain below, resting at a somewhat steep angle against the denuded edges of the underlying beds. From this and other localities it becomes obvious that the latter formation has been deeply and extensively denuded before and during the deposition of the surface strata, which form the chief subject of this communication.” Professor Fontaine commenced his work on the Potomac at about this time, publishing during 1879 a series of three articles in the American ° MARYLAND GEOLOGICAL SURVEY. 39 Journal of Science entitled Notes on the Mesozoic of Virginia, and in- cluding the Triassic in his discussion. The flora received considerable attention and the materials were grouped into the “ Fredericksburg belt ” and the “ Petersburg belt,” the one corresponding with what he after- ward called the Fredericksburg beds and the other answering to the James River beds, both in large part referable to the Patuxent forma- tion. It was in the part published in the February number of the Ameri- can Journal of Science that the “ archaic dicotyledons” of the Potomac were first mentioned in the following language: “ With the plants above named, I find certain netted veined leaves, which by their nervation can- not be distinguished from Angiosperms. Had they been found with Cretaceous or Tertiary plants I think no one would hesitate to consider them as such. As, however, they occur with a well-marked upper Juras- sic flora, I hesitate to pronounce them to be Angiospermous plants with- out a more careful study and extended comparison than I have as yet been able to make. They are certainly not ‘Dictyophyllum,’ which is the genus of fossil ferns that stands nearest to them. But when we find such a development of undoubted Angiosperms in the lowest Cretaceous beds of New Jersey and of the west, we should expect to find at least their ancestors in the Jurassic flora.” Further along he speaks of the evidence as to the age of the iron-ore clays as. pointing strongly to the conclusion that they were Wealden. In a lecture by Professor Uhler, an abstract of which was published in 1883, considerable space was given to what is now regarded as part of the Potomac Group, and which he calls Upper Jurassic or Wealden, giving it a thickness of 500 feet in the Baltimore region. In the spring of 1884 Professor Ward prepared a short paper on Mesozoic Dicotyledons, in which he mentions Fontaine’s archaic dicotyle- dons, which he states are from the Upper Jurassic of Virginia, and ex- presses the hope that the problem of the origin of this group is at last approaching solution. About this time Professor Fontaine joined the staff of the U. S. Geological Survey, his first administrative report ap- pearing in 1885 in the Sixth Annual Report. In 1886 the name Potomac formation first appeared in print in a paper 40 Tur Lower Cretacrous Deposits oF MaryLAND contributed by W J McGee to the Report of the Health Officer of the District of Columbia for 1885. In 1887 Professor Fontaine submitted a paper embodying his results to the American Association for the Ad- vancement of Science, a brief abstract of which was published in 1888, from which the following is quoted: “The name Potomac formation has been applied to a series of newer Mesozoic sands, gravels, and clays, sometimes cemented into sandstones and conglomerates, which appear along the inner margin of the Coastal Plain, forming the basal member of the undisturbed Mesozoic and Cenozoic formations of the eastern United States, in Virginia, Maryland, Delaware, and perhaps other States. It comprises two members—an upper, consisting generally of variegated clays which are well exposed about Baltimore, and a lower, consisting predominantly of sands and gravels, well exposed in the bluffs of the Potomac River below Washington. The upper member is known only north of Fredericksburg, and the lower is best developed from Washington to Richmond. “The age of the formation, as indicated by its flora, appears to coin- cide approximately with that of the Lower and Middle Neocomian [mis- printed Neuronian] of Greenland and Europe.” It was in December, 1887, that Mr. J. B. Hatcher, under instructions from Professor O. C. Marsh, collected a considerable number of verte- brate bones from an iron mine near Muirkirk, Md. He also found in the same beds some small cones representing the genus Sequoia, and much silicified wood and lignite. The bones were described by Professor Marsh and the results published at once. As to the geological signifi- cance of these forms, Professor Marsh says: “ The fossils here described, and others from the same horizon, seem to prove conclusively that the Potomac formation in its typical localities in Maryland is of Jurassic age, and lacustrine origin. There is evidence that some of the supposed northern extensions of this formation, even if of the same age, are of marine or estuary origin.” The next year Professor Uhler read a paper before the American Philosophical Society in which the name Baltimorean was proposed for the lower beds and Albirupean for the upper, which, however, included MARYLAND GEOLOGICAL SURVEY. ° LOWER CRETACEOUS, PLATE Ill Fic. I.—VIEW SHOWING COARSE, HIGHLY INCLINED AND CROSS-BEDDED PATUXENT SANDS NEAR HOMESTEAD, BALTIMORE CITY. Fic, 2.—VIEW SHOWING KAOLIN IN THE PATUXENT FORMATION IN CUT ON P. B. & W. RR. NEAR PERRYVILLE, CECIL COUNTY. MARYLAND GEOLOGICAL SuRVEY 41 strata younger than the Potomac. He enumerated the various types of plant remains which he had collected from the different horizons. The same year McGee published his paper entitled “ Three Formations of the Middle Atlantic Slope,” devoting much of his space to the Po- tomac formation, erroneously referring the Bryn Mawr gravels, the “yellow rocks,” above Trenton, New Jersey, and the “sand hills” east of Princeton, New Jersey, to the Older Potomac. At the meeting of the National Academy of Sciences held in the spring of 1888 Professor Ward prepared a paper on the “ Evidence of the fossil plants as to the age of the Potomac formation,” which was published in the August number of the American Journal of Science, from which the following may be quoted: “ On numerous occasions, dating as far back as 1878, I have expressed the opinion that the dicotyledons could not have had their origin later than the middle Jura, and it will not surprise me if the final verdict of science shall place the Potomac formation, at least the lower member in which the plants occur, within that geologic system. While the re- maining types point strongly in this direction, I do not regard the dicotyledons as at all negativing, but even more strongly suggesting, - this view. “Still, it may be admitted that, according to the ordinary modes of arguing from similar statistics, the sum of all the facts here presented would make the Potomac, considered from the view of the flora alone,. homotaxially equivalent to the Wealden of England and north Germany, now usually included in the Cretaceous systerh. If the vertebrate re- mains are Jurassic and the flora Cretaceous we only have here another confirmation of a law exemplified in so many other American deposits, that, taking European faunas and their correlated floras as the standard of comparison, the plant life of this country is in advance of the animal life. This law has been chiefly observed in our Laramie and Tertiary deposits, but is now known to apply even to Carboniferous and De- vonian floras. It is therefore to expected that we shall find it to prevail during the Mesozoic era. If, therefore, it be really settled that the fauna of the Potomac series is homotaxially Jurassic, and we take our 42 Tue Lower Cretaceous Depostrs oF MARYLAND starting point from the Old World geology, there will be no more ob- jection to regarding the Potomac flora as Jurassic than there is now in contemplating the Laramie flora as Cretaceous. In fact, so far as the character of the flora is concerned, there is much less difficulty in the case of the Potomac than in that of the Laramie, since, as I have shown, the Potomac flora, viewed in all its bearings, cannot be said positively to negative the reference of the formation to the Jurassic upon the evi- dence of the plants alone. “T do not, however, desire to be understood as arguing for the Juras- sic age of the Potomac formation. The most that it is intended to claim is that, if the stratigraphical relations and the animal remains shall finally require its reference to the Jurassic, the plants do not present any serious obstacles to such reference.” European paleobotanists having manifested much interest in the Potomac flora, a statement was prepared by Professor Fontaine for Feist- mantel, the celebrated Bohemian savant who made it the subject of a paper which appeared in the proceedings of the Royal Bohemian Society in 1889. This same year saw the appearance of Dr. Knowlton’s long- delayed work on the fossil wood and lignites of the Potomac formation, a summary of which he had already contributed to the 1888 meeting of the American Association for the Advancement of Science, an abstract also appearing in the American Geologist. Professor Uhler also pub- lished two additional papers at this time announcing the finding of his Albirupean formation at Ft. Foote and on Piscataway Creek. In 1890 Professor Fortaine’s Monograph was issued. In it are de- scribed and illustrated 365 species, so called, of fossil plants, including 75 more or less nominal species of dicotyledons. The age is assumed to be Neocomian, under which term are included the Wealden, Urgonian, and Aptian groups of European geologists. In Professor Clark’s account of the “Third Annual Geological Expe- dition into Southern Maryland and Virginia,” published in 1890, the Albirupean is recognized as distinct from the underlying Potomac. The same year N. H. Darton discussed the Potomac in a paper read before the Geological Society of America, and the literature to date was passed MARYLAND GEOLOGICAL SURVEY 43 in review by Dr. C. A. White in his Correlation Paper on the Cretaceous, published in 1891. Nearly twenty years after Tyson’s discovery of cycad trunks in the iron-ore beds of Maryland, Mr. Arthur B. Bibbins took up the quest, and during the next few years succeeded in obtaining from the inhabitants of the region a very large number of trunks and fragments. These were submitted for critical study to Professor Ward, who in 1894 published a revision of the genus Cycadeoidea, to which all of the Maryland forms belonged. Mr. Bibbins continued to collect more material, and in 1897 Professor Ward published descriptions of seven species from Maryland. In a paper entitled “ Albirupean Studies,” and published in 1892, Professor Uhler makes further contributions to the knowledge of the Potomac, but his stratigraphic conclusions are, according to Professor Ward, set forth in a rather ambiguous manner. In a paper in Science, published in 1894, Professor Ward makes an interesting comparison between the Potomac flora and that from the Mesozoic of Portugal made known by the Marquis Saporta. He suggests the following long-range correlations: James River beds=Infra Valan- ginian, Fredericksburg beds= Valanginian, Mount Vernon beds=Ur- gonian, Brooke beds= Aptian, and Raritan beds=Albian. In the same number of Science appeared a note by F. A. Lucas on the Vertebrate re- mains from the Maryland Potomac, Allosaurus, Pleuroccelus, Priconodon and Astrodon being the forms enumerated. The same year Mr. Bibbins published a summary of his Potomac studies, and the Fredericksburg folio of the U. 8. Geological Survey by N. H. Darton was issued. It included a large area of the Virginia Potomac, which was described and mapped as a single unit, however. A number of important papers appeared during 1896. Among these are Professor Ward’s elaborate discussion entitled: “The Potomac For- mation,” in which he subdivides it into The James River Series, The Rappahannock Series, The Mount Vernon Series, The Aquia Creek Series, The Iron Ore Series, The Albirupean Series, and the Island Series. The flora of each is discussed and considerable space is devoted to the newly discovered flora of the clays on the Mt. Vernon estate. 44 Tur Lowsr Creracrous Deposits oF MARYLAND This was followed by Professor Marsh’s memoir on “The Dinosaurs of North America,” which contained the descriptions and figures of the Maryland material collected from the iron-ore clays by J. B. Hatcher. At the same time appeared Professor Ward’s paper on “ Some Analogies in the Lower Cretaceous of Europe and America,” in which the Potomac was compared with the Wealden of England, the “ Scaly Clays” of Italy, and the Mesozoic of Portugal. Toward the close of the year Professor Fontaine’s long-delayed geological paper on the Potomac appeared as a Bulletin of the U. 8. Geological Survey. It contained admirable de- scriptions of local sections and the first geological map of the deposits, covering the country between Baltimore and Petersburg. No attempt was made, however, to show the areal extent of the subdivisions of the Potomac, and the Virginia deposits are regarded as Lower and those in Maryland as Upper Potomac. Professor Newberry’s monograph on the Amboy clay flora appeared at this time as a posthumous publication un- der the editorship of Arthur Hollick. About this time Professor Marsh published two brief papers asserting the Jurassic age of the Potomac as well as of the Cretaceous beds on Long Island and to the eastward. This called forth a discussion in the col- umns of Science which was participated in by Arthur Hollick, L. F. Ward, G. K. Gilbert, R. T. Hill, and Jules Marcou. In the fall of 1897 Clark and Bibbins published a full summary of the tesults arrived at in their study of the Potomac of Maryland, dividing it into four formations—the Patuxent, Arundel, Patapsco, and Raritan. The two former formations were provisionally referred to the Jurassic and the two latter to the Lower Cretaceous. In 1898 Professor Marsh replied to his critics and reasserted the Juras- sic age of the Potomac beds. In 1902 Clark and Bibbins published a second paper on the Potomac of Maryland, in which the conclusions are essentially the same as in their earlier paper. This paper was well illustrated and contained an admirable map showing the areal extent of the different members of the Potomac Group as developed in Maryland, the first of its kind ever published. This same year the Cecil County report of the Maryland MARYLAND GEOLOGICAL SURVEY 45 Geological Survey appeared. The Coastal Plain geology was contributed by G. B. Shattuck, that for the Potomac largely from Mr. Bibbins’ notes. The three, Potomac formations present in that region, the Patuxent, Patapsco, and Raritan, are delineated upon the large scale county map. In 1906 the Dover folio of the U. S. Geological Survey prepared by Dr. B. L. Miller was published. This included a considerable area in Delaware and northeastern Maryland, in which the Patapsco and Raritan formations were described and mapped. Although it bears the date 1905 it was in 1906 that Ward’s second paper on the Status of the Mesozoic Floras of the United States was issued. Over two hundred and fifty pages are devoted to the Potomac flora of Maryland and Virginia, two additional species of Maryland eycad trunks are described, and the large amount of material collected by Mr. Bibbins for the Maryland Geological Survey and Goucher College is discussed in the systematic part prepared by Professor Fontaine. The correlations and stratigraphy are by Ward, who accepts the Maryland Survey formational names for that State, uniting, however, the Patuxent and Arundel formations. For Virginia the James River and Rappahan- nock are united and made the equivalent of the Patuxent and Arundel, and the Mount Vernon and Brooke beds are correlated with the Patapsco formation and an excellent map prepared by Mr. Bibbins shows the distri- bution of the four formations of the Potomac Group in Maryland. Pro- fessor Ward’s final conclusion was that the whole Potomac Group is of Cretaceous age, the older Potomac forming a part of the European Wealden, which he regards as Cretaceous. ‘The report on the Physical Features of Maryland by Clark and Mathews, published this same year, contained a new geological map of the State on which the different Potomac members are shown, and the text contained a full description and characterization of them. ’ In 1907 the Patuxent Folio of the U. 8. Geological Survey was pub- lished by Shattuck, Miller and Bibbins. All the members of the Potomac Group are fully described and mapped. , ' Jn 1910 Berry published a short article in the Journal of Geology showing that the Raritan formation was of Upper Cretaceous age. This Tue Lower Cretacrous Deposits or MARYLAND 46 “IOATY SoUBe se ‘Solas JOATY some ‘1aquoul pus yoouusyeddyy quoxnqed | 9TOISpUBS IO 1aMO'T ‘goT10s yoouusqeddey 4 ‘ ‘ UONBVULIO Isseinge “solias UOUI9A “JW ‘OIOZOSAW YAONNOA TOUISA “IA Tapunly 10 aeMojog 10 ‘so]108 YOIIO Binby OVNOLOd ‘ayoorg ‘oosdyeg ‘$0118 910 TOIT staquiet Avro 10 teddy “9061 "L681 “9681 “G68T “6881 ‘pleM “AT ‘sUIggIg pus HIBIO ‘asIeW ‘0 ‘O ‘PIeM “AT ‘ours}aOd “WM *19qulom aU0spUBs 10 1aMO'T ‘(sABlo pus spuss) 2}1100 19M0'T ‘uve10 MBq OVWOLOd ‘kero wopywom, *sn0908}019 aa “19qulew “(Bo 910 UOJI) feo 10 raddy 9111900 asddq. "8881 *S88T “IS8T “698T “TPST “12100 “Hd ‘eeDoW £ M ‘ISH “H “WO ‘s1ad0y “dM ‘uoshL, Ld ‘sreSoy “dM ‘ETIVL OINONOXVL FAILVUVAWOO MarYLAND GEOLOGICAL SURVEY 47 same year Clark published a paper describing the progress of the work on the Geology of the Middle and Northern Atlantic Coastal Plain, in which the various formations were briefly discussed and the Lower Cre- taceous age of the Patuxent and Arundel formations affirmed. The ' Raritan was referred to the Upper Cretaceous and the Potomac Group was limited to the Lower Cretaceous. Berry also published a brief paper discussing the southward extension of the Patuxent formation into North Carolina, and showing that the Arundel formation is absent in Virginia, and that the Patapsco formation is transgressed and disappears in cen- tral Virginia beneath Tertiary deposits. The latter author also pub- lished several systematic papers upon some of the more important genera of Potomac plants. The accompanying table shows the varying nomenclature of the more important students of the Potomac deposits, commencing with that of W. B. Rogers in 1841. BIBLIOGRAPHY 1799 Latrose, B. Henry. Memoir on the sand hills of Cape Henry in Virginia. Trans. Amer, Philos. Soc., vol. iv, 1799, pp. 439-443, Philadelphia. 1809 Larrosg, B. H. An account of the freestone quarries on the Potomac and Rappahannoc rivers. Trans. Amer. Philos. Soc., vol. vi, part ii, 1809, pp. 283-293. 1824 Fincu, JoHn. Geological Essay on the Tertiary Formations in Amer- ica. (Read Acad. Nat. Sci. Phila., July 15, 1823.) Amer. Jour. Sci., vol. vii, 1824, pp. 31-43. 1829 Vanuxem, L., and Morton, 8. G. Geological Observations on Sec- ondary, Tertiary, and Alluvial formations of the Atlantic coast of the United States arranged from the notes of Lardner Vanuxem. Jour. Acad, Nat. Sci., Phila., vol. vi, 1829, pp. 59-71. 4 48 Tue Lower Cretaceous Deposits or MARYLAND 1833 Hircucocx, Epwarp. Report on the Geology, Mineralogy, Botany, and Zodlogy of Massachusetts. Amherst, 1833, pp. 201-202. 1835 Cremson, THomas G. Notice of a geological examination of the country between Fredericksburg and Winchester, in Virginia, including the gold region. Trans. Geol. Soc. Pa., vol. i, pt. 2, Phila., 1835, pp. 298-313, pl. xvii. TayLor, Ricuarp ©. Review of geological phenomena, and the de- ductions derivable therefrom, in two hundred and fifty miles of sections in parts of Virginia and Maryland; also notice of certain fossil acotyledo- nous plants in the Secondary strata of Fredericksburg. Trans. Geol. Soc. Pa., vol. i, pt. 2, Phila., 1835, pp. 314-325, pls. xviii-xix. 1836 Rogers, Witt1am B. Report of the Geological Reconnaissance of the State of Virginia, made under the appointment of the board of public works. Phila., 1836, p. 61. 1840 Rogers, Witt1am B. Report of the Progress of the Geological Survey of the State of Virginia for the year 1839. Richmond, 1840. 1841 Rogers, Witt14m B. Report of the Progress of the Geological Survey of the State of Virginia for the year 1840. Richmond, 1841. 1844 Rocrrs, H. D. Address delivered at the Meeting of the Association of American Geologists and Naturalists. Amer. Jour. Sci., vol. xlvii, 1844, pp. 187-160, 247-278. 1855 TayLor, RicHarp C. Statistics of Coal, 2d Ed. Phila., 1855, p. 299. MaryYLanp GEoLocicaL Survey: 49 1859 JOHNSTON, CHRISTOPHER. Am. Journ. Dental Science, N. S., vol. ix, Phila., 1859, p. 341 1860 Tyson, P. T. First Report of Philip T. Tyson, State Agricultural chemist, to the House of Delegates of Maryland, Jan., 1860. 8vo. 145 pp. Annapolis, 1860. Maps. Md. Sen. Doc. [E]. Md. House Doe. [C]. 1865 Lripy, JOSEPH. Smith. Cont. to Knowledge, No. 192, vol. xiv, article vi, 1865, p. 102, pl. xiii, figs. 20-23; pl. xx, fig. 10. 1868 Corz, E. D. On the discovery of the fresh-water origin of certain deposits of sand and clay in west New Jersey. Proc. Acad. Nat. Sci., Phila., vol. xx, 1868, pp. 157-158. Mavcry, M. F. Physical survey of Virginia. Richmond, i, 1868, 8°, 90 pp.; ii, 1878, 8°, 142 pp. 1875 Rogers, W. B. On the Gravel and Cobblestone Deposits of Virginia and the Middle States. Proc. Boston Soc. Nat. Hist., vol. xviii, 1875, pp. 101-106. 1876 Horcnxiss, Jep. Virginia: a geographical and political summary, embracing a description of the State, its geology, soils, minerals, climate, etc. Richmond, 1876, 8vo, pp. iv, 319, and 4 maps. 1878 Hetnricu, 0. J. The Mesozoic formation in Virginia. Trans. Am. Inst Min. Engs., vol. vi, 1878, pp. 227-274. 1879 Fontaine, Wu. M. Notes on the Mesozoic of Virginia. Am. Journ. Sci., 3d. ser., vol. xvii, 1879, pp. 25-39, 151-157, 229-239. 50 Tue Lower Cretacrous Deposits oF MARYLAND / 1881 Newserry, J. S. American Cretaceous Flora. Nature, vol. xxiv, 1881, pp. 191, 192. 1883 Unter, P. R. Geology of the Surface Features of the Baltimore Area. Johns Hopkins Univ. Circ., vol. ii, Feby., 1883, pp. 52-53. (Abst.) Science, vol. i, 1883, pp. 75-76, 277. 1884 - Rogers, Wintiam Barton. A Reprint of Annual Reports and other Papers, on the Geology of the Virginias, by the late William Barton Rogers. New York, 1884. Warp, Lester F. On Mesozoic Dicotyledons. Am. Journ. Sci., 3d ser., vol. xxvii, 1884, pp. 292-303. 1885 McGzr, W J. Geological Formations underlying Washington and Vicinity. Rept. Health Officer of the District of Columbia for the year ending June 30, 1885, by Dr. S. Townsend, pp. 19-21, 23-35. (Abst.) by author in Am. Journ. Sci., 3d ser., vol. xxxi, 1886, pp. 473-474. 1886 Newserry, J.S. On the Cretaceous Flora of North America. Proc. Am. Assn. Adv. Sci., vol. xxxv, 1886, p. 216. 1887 Fontaine, W. M. The Flora of the Potomac Formation in Virginia. Proc. Am. Assn. Adv. Sci., 36th meeting, New York, 1887, Salem, 1888, pp. 275-276. 1888 McGezsz, W. J. Three formations of the Middle Atlantic Slope. Am. Journ. Sci., 8d ser., vol. xxxv, 1888, pp. 120-148, 328-380, 367-388, 448- 466, pls. 2 and 6. Marcov, Jutes. American Geological Classification and Nomencla- ture. 75 pp., Cambridge, Mass., 1888. MarYLAND GEoLoGicAL SURVEY 51 MarsnH, 0. C. Notice of a new genus of Sauropoda and other dino- saurs from the Potomac formation. Am. Journ. Sci., 3d ser., vol. xxxv, 1888, pp. 89-94, 9 text figs. Untizr, P. R. Sketch of the history of the Maryland Academy of Sciences. Trans. Md. Acad. Sci., vol. i, 1888, pp. 7-8. Warp, Lester F. Evidence of the fossil plants as to the age of the Potomac formations. Am. Journ. Sci., 3d ser., vol. xxxvi, 1888, pp. 119-131. 1889 FEISTMANTEL, OrToKarR. Ueber die bis jetzt altesten dikotyledonen Pflanzen der Potomac-Formation in N. America, mit brieflichen Mit- theilungen von Prof. Wm. M. Fontaine. Sitzb. k. béhm. Ges. d. Wiss., Jahrg., 1889, vol. i, pp. 257-268. Ueber die bis jetzt geologisch altesten Dikotyledonen. Zeitsch. deutsch. geol. Ges., Berlin, vol. xli, 1889, pp. 27-34. Knowlton, Frank Hatt. Fossil wood and lignite of the Potomac formation. Bull. U. S. Geol. Surv. No. 56, 1889, 72 pp., 7 pl. (Abstract) Amer. Assn. Adv. Sci., Cleveland, 1888, Salem, 1889, pp. 207-208. Am. Geol., vol. iii, 1889, pp. 99-106. 1890 Fonrainz, Witt1Am Morris. The Potomac or Younger Mesozoic Flora. Mon. U. S. Geol. Surv., vol. xv, 1889, text, xiv, x, 377 pp.; atlas, 180 pls. Reviewed, Am. Journ. Sci. (iii), vol. x1, 1890, pp. 168, 169. Unter, P.R. Additions to observations on the Cretaceous and EKocene formations of Maryland. Trans. Md. Acad. Sci., vol. i, 1889-1890, pp. 45-72 . Notes and illustrations to “ Observations on the Cretaceous and Eocene formations of Maryland.” Trans. Md. Acad. Sci. vol. i, 1890, pp. 97-104. Warp, Lester F. The Potomac or Younger Mesozoic Flora by Wm. Fontaine. (Review.)- Am. Journ. Sci. (iii), vol. xxxix, 1890, p. 50. 52 Tun Lower Cretacrous Deposits of MaRYLAND 1891 Darton, N. H. Mesozoic and Cenozoic formations of eastern Vir- ginia and Maryland. Bull. Geol. Soc. Am., vol. ii, 1891, pp. 431-450, pl. xvi. (Abst.) Am. Geol., vol. viii,-1891, p. 185; Am. Nat., vol. xxv, 1891, p. 658. Wurtz, Cuartes A. Correlation Papers, Cretaceous. Bull. U. 8. Geol. Surv., No. 82, 1891, pp. 88-92. WittaMs, Go. H. (Editor.) Geological Map of Baltimore and Vicinity. Published by the Johns Hopkins University on the topographic base of the U. S. Geological Survey. 234 x 24, contour 20 feet, 18 colors, Scale 1/62,500. (J. H. U.) , and CrarxK, Wm. B. Report on short excursions made by the Geological Department of the University during the autumn of 1891. Johns Hopkins Univ. Cir. No. 95, vol. xi, 1892, pp. 37-39. Guide to Baltimore, with an account of the Geology of its environs and three maps. 1892 Unter, P. R. Albirupean studies. Trans. Md. Acad. Sci., vol. i, 1892, pp. 185-201. 1893 McGzz, W J. With the collaboration of G. H. Williams, Bailey Willis, and N. H. Darton. Compte-Rendu de la 5me sess. Congrés Géol. Inter, Washington, 1891; Washington, 1893, pp. 219-251. 1894 Ciark, Wm. Buttock. The Climatology and Physical Features of Maryland. 1st Biennial Rept. Md. State Weather Service, 1894. Darton, N. H. Artesian Well Prospects in Eastern Virginia, Mary- land, and Delaware. Trans. Amer. Inst. Min. Eng., vol. xxiv, 1894, pp. 372-397, pls. 1 and 2. Fredericksburg Folio. Explanatory sheets. U. S. Geol. Surv. Geol. Atlas, folio No. 13, Washington, 1894. MarRYLAND GEOLOGICAL SURVEY 53 Warp, Luster F. Fossil cycadean trunks of North America, with a revision of the genus Cycadeoidea Buckland. Proc. Biol. Soc. Wash., vol. ix, 1894, pp. 75-88. Recent discoveries of cycadean trunks in the Potomac forma- tion of Maryland. Bull. Torrey Club, vol. xxi, 1894, pp. 291-299. 1895 Bipsins, ArtHUR. Notes on the paleontology of the Potomac forma- tion. i Johns Hopkins Univ. Circ., vol. xv, No. 121, 1895, pp. 17-20, 1 pl. Kwow.tton, F. H. The oldest dicotyledons. Popular Science News, vol. xxix, 1895, pp. 49-51, 66-68, 20 text figs. Liman, Bengamin SmitH. Report on the New Red of Bucks and Montgomery Counties. Pa. State Geol. Summ. Final Rept., vol. iii, pt. 2, 1895, pp. 2634-2635. Warp, Lester F. The Mesozoic flora of Portugal compared with that of the United States. Science, N. S., vol. i, 1895, pp. 337-346. The Potomac Formation. Fifteenth Ann. Rep. U. S. Geol. Surv., 1895, pp. 307-397, pls. ii-iv. 1896 Darton, N. H. Artesian Well Prospects in the Atlantic Coastal Plain Region. Bull. U. S. Geol. Surv. No. 138, 1896, 228 pp., 19 pl. House Misc. Doc., 54th Cong., 2d sess., vol. —, No. 28. FonrTaIne, WILLIAM Morris. The Potomac formation in Virginia. Bull. U. S. Geol. Surv., No. 145, 1896, 149 pp., map. GitBERT, G. K. Age of the Potomac formation. Science, N. S., vol. iv, 1896, pp. 875-877. Hitz, Ropert T. A question of classification. Science, N. S., vol. iv, 1896, pp. 918-920. Marsu, O. C. The dinosaurs of North America. Sixteenth Ann. Rept. U. S. Geol. Surv., pt. i, 1896, pp. 183-414, pls. ii-Ixxxv. The geology of Block Island. Am, Journ. Sci., 4th ser., vol. ii, 1896, pp. 295-298, 375-377. 54 Tur Lower Cretaceous Deposits oF MARYLAND The Jurassic formation on the Atlantic coast. Am. Journ. Sci., 4th ser., vol. ii, 1896, pp. 483-447. Warp, Lester F. Some analogies in the Lower Cretaceous of Europe and America. Sixteenth Ann. Rept. U. S. Geol. Surv., pt. 2, 1896, pp. 463-542, pls. xevii-cvii. 1897 Ciarx, WILLIAM Butuocg, and Brspins, ARTHUR. The stratigraphy of the Potomac group in Maryland. Journ. Geol., vol. v, 1897, pp. 479-506. Warp, Luster F. Descriptions of the species of Cycadeoidea or fossil cycadean trunks, thus far discovered in the iron-ore belt, Potomac forma- tion, of Maryland. Proc. Biol. Soc. Wash., vol. xi, 1897, pp. 1-17. Professor Fontaine and Doctor Newberry on the age of the Potomac formation. Science, N. S., vol. v, 1897, pp. 411-423. 1898 Kwowiton, Frank Hatt. A Catalogue of the Cretaceous and Ter- tiary plants of North America. U. S. Geological Survey, Bulletin 152, 8°, 247 pp., 1898. 1900 MoGzz, W J. [The Sixteenth Street Section at Washington, D. C.] Science, N. S., vol. xii, 1900, pp. 990-991. 1902 Berry, Epwarp W. Notes on Sassafras. Bot. Gaz., vol. xxxiv, 1902, pp. 426-450. Bonsteet, J. A. Soil Survey of Prince George’s county, Md. Field Oper. Bureau Soils, 1901, U. S. Dept. Agri., Third Rept. Bureau Soils, 1902, pp. 173-210, pls. xxi-xxv, with map. Dorsey, C. W., and Bonstrst, J. A. The Soils of Cecil county. Md. Geol. Surv., Cecil County, 1902, pp. 227-248, pls. xx-xxii, with map. Ciark, W. B., and Brspins, A. Geology of the Potomac group in the middle Atlantic slope. Bull. Geol. Soc. Am., vol. xiii, 1902, pp. 187-214, pls. xxii-xxviil. MARYLAND GEOLOGICAL SURVEY 55 Riss, H. Report on the Clays of Maryland. Md. Geol. Surv., vol. iv, 1902, pp. 205-505, pls. xix-lxix. SHartuck, G. B. The Geology of the Coastal Plain Formations. Md. Geol. Surv. Cecil County, 1902, with geological map, pp. 149-194, figs. 8-11, pls. xii-xvi. 1903 Berry, Epwarp W. Aralia in American Paleobotany. Bot. Gaz., vol. xxxvi, 1903, pp. 421-428. The American Species referred to Thinnfeldia. Bull. Torrey Bot. Club, vol. xxx, 1903, pp. 438-445. 1905 Bissins, ArtHur. Stratigraphical position and General Nature of the Maryland Cycads. In. Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 411-415. 1906 CiarK, Wm. Buttock, and Maturws, Epwarp B. Report on the Physical Features of Maryland (with map). Maryland Geol. Survey, Special Publication, vol. vi, pt. i, Baltimore, 1906. Miter, Benzamin LeRoy. Dover Folio. Explanatory Sheets. U. S. Geol. Survey, Geol. Atlas, folio No. 137, Washington, 1906. Warp, Lester F. Status of the Mesozoic floras of the United States. Second paper, by Lester F. Ward, with the collaboration of Wm. M. Fontaine, Arthur Bibbins, and G. R. Wieland. Washington, Gov’t print. off. (1905), 1906. 2v. exix pl. (incl. maps) 304% x 23 cm. (U.S. Geological Survey, Mono- graphs, vol. xlviii). Contents.—pt. i. Text.—pt. ii. Plates. 1907 Brpsins, ARTHUR BARNEVELT. Additional Evidence of Tropical Cli- mate on the Middle Atlantic Coast during the Lower Cretaceous. (Abstract) Science (N. 8.), vol. xxv, 1907, pp. 297, 298. SHattuck, Grorce BurBanx; MILuer, BengzamMin LeRoy, and Brs- Bins, ARTHUR. Patuxent Folio. Explanatory Sheets. U. S. Geol. Survey, Geol. Atlas, folio No. 152, Washington, 1907. 56 Tan Lower Creracrous Deposits oF MARYLAND 1910 Berry, Epwarp W. A Revision of the Fossil Plants of the genera Acrostichopteris, Tzeniopteris, Nilsonia, and Sapindopsis from the Po- tomac Group. Proc. U. S. Natl. Mus., vol. xxxviii, 1910, pp. 625-644, A Revision of the Fossil Plants of the genus Nageiopsis of Fontaine. Proc. U. §. Natl. Mus., vol. xxxviii, 1910, pp. 185-195, tf. 1, 2. The epidermal characters of Frenelopsis ramosissima. Bot. Gazette, vol. 1, 1910, pp. 305-309, tf. 1, 2. Geologic relations of the Cretaceous Floras of Virginia and North Carolina. Bull. Geol. Soc. Amer., vol. xx, 1910, pp. 655-659. CuarK, Wm. Buniock. Results of a recent investigation of the coastal plain formations in the area between Massachusetts and North Carolina. Bull. Geol. Soc. Amer., vol. xx, 1908, pp. 646-654. 1911 Berry, Epwarp W. A Lower Cretaceous species of Schizeacee from eastern North America. Annals of Botany, vol. xxv, 1911, pp. 193-198, tf. 1, pl. xii. A revision of several genera of gymnospermous plants from the Potomac Group in Maryland and Virginia. Proc. U. S. Natl. Mus., vol. x1, 1911, pp. 289-318. A revision of the fossil ferns from the Potomac Group which have been referred to the genera Cladophlebis and Thyrsopteris. Proce. U. 8. Natl. Mus., vol. xli, 1911, pp. 307-332. STRATIGRAPHIC AND PALEONTOLOGIC CHARACTERISTICS The Lower Cretaceous deposits of Maryland and adjacent areas have long been studied by many independent workers who have approached the problem from nearly as many different points of view. This fact, together with the proverbially complicated stratigraphy, has given rise to a highly varied taxonomy which is set forth in the previous chapter and the accompanying comparative taxonomic table. x MARYLAND GEOLOGICAL SURVEY 5% The Lower Cretaceous deposits are more highly differentiated in Mary- land than elsewhere along the Atlantic border, as is seen in both their lithologie and paleontologic diversity. The several formations present certain common features which need to be taken into considera- tion in any discussion of the strata. The deposits, which are largely sands and clays of varying strati- graphic and lithologic characteristics, are, for the most part, uncon- solidated, although certain marked exceptions to this are to be seen in the locally developed sandstone beds in the lower part of the series. The deposits in general dip at progressively lower angles in passing , upward in the series, although the Arundel formation affords some striking exceptions to this general rule. Again, the deposits thicken down the dip within the limits of the area of outcrop, although they apparently thin farther to the seaward, as shown by the well borings in which Lower Cretaceous strata are encountered. The stratigraphic re- lations show that after the deposition of the Patuxent and Arundel for- mations they were gradually transgressed toward the northward by the Patapsco formation before the close of Lower Cretaceous time. A study of the organic remains reveals a gradual progress in the types of plant life from the Patuxent through the Arundel and Patapsco, especially in the gradual advent of dicotyledonous types of plant life. These various features will be fully discussed in the descriptions of the several for- mations. Tur Potomac Group The Potomac Group, originally named by McGee for the deposits thus characterized in this report, was divided by Clark and Bibbins into the Patuxent, Arundel, and Patapsco formations, although they and others included within the Potomac certain higher deposits of somewhat sim- ilar character (Raritan formation) which are now recognized as of Upper Cretaceous age. A sufficient lithologic and paleontologic differ- ence occurs in these higher deposits to warrant the restriction of the term Potomac to those formations characteristic of the Potomac River region where they were first described by McGee under the name of the “ Potomac formation.” 58 Tue Lower Cretaceous Deposits or MARYLAND THE PATUXENT FORMATION Name anp Synonymy.—The Patuxent formation was so designated from the Patuxent River in Maryland, in the drainage basin of which its deposits were first recognized as an independent formation and named by Clark and Bibbins.* It is in part the “feldspathic sandstone” of Rogers, the “lower oolite” .of Tyson, and the “ Fredericksburg” or “lower sandstone member” of Fontaine and McGee. It includes most of the “ James River” and a part of the “ Rappahannock” and “ Aquia Creek series” of Ward, and also a part of the “ Baltimorean ” of Uhler. AREAL DistripuTion.—The Patuxent formation extends across the State in an irregular and at times interrupted belt, some 5 or 6 miles in average width, from the Delaware line through Elkton, Baltimore, and Laurel to the city of Washington. It forms generally the landward border of the Coastal Plain, although its outcrop is in places buried be- neath later deposits while seaward its surface continuity is interrupted by the principal water-ways, such as the Susquehanna, Gunpowder, Pa- tapsco, and Potomac rivers. Outliers are found on the crystalline rocks to the west of the main body of the deposits, the two most conspicuous being the outliers at Catonsville and Lutherville. The former occupies one of the highest levels containing Coastal Plain deposits while the latter is found in a limestone valley a hundred feet lower than similar beds not far to the southeastward. The Patuxent deposits in the Fall-line zone afford a very broken relief in the vicinity of the stream channels. The exposed hillocks of Patuxent materials with their slight cover of vegetation often suggest a bad land topography. Patuxent deposits have been observed in Maryland from over 400 feet in elevation near Catonsville to below 400 feet in a well at Indian Head. LirHoLocic CHaracter.—The materials constituting the Patuxent formation are on the whole arenaceous, although argillaceous elements ' likewise appear. The sands, which are predominantly cross-bedded, are 1 Jour. Geol., vol. v, p. 481, 1897. MarYLAND GEOLOGICAL SURVEY 59 sharp and the gravel mostly subangular, and not as well rounded as that of the overlying Pleistocene. The sand and gravel often contain a con- siderable admixture of kaolinized feldspar, producing what is known as arkose. To the indurated derivative Rogers gave the name “ feldspathic sandstone.” Extensive deposits of rather fine and even-grained sandy gravel occur near the base of the formation, notably in the valley of Herring Run, at Roland Park, and near Cub Hill in Baltimore County, where the materials have been employed to a greater or less extent as road metal and for concrete. The basal gravels are often coarse and cobbly, and adjacent to the crystalline floor are often indurated by hydrous iron oxide to a resistant ferruginous conglomerate. Toward the northward, in the vicinity of Perry Hall, Baltimore County, and in the Broad Creek valley in Cecil County, the basal conglomerate is of light color and is filled with angular fragments of quartz. Buff-colored sands of fine-grained texture with some admixture of brownish loam are common in the vicinity of Baltimore City, where they have been exten- sively employed as building sands. White glass sands somewhat arkosic have been worked to some extent at Westport in Baltimore County. The Patuxent sands are often indurated by hydrous oxide of iron and take on very irregular and fantastic shapes, including hollow cylinders, in- tricately corrugated plates and spherical and ellipsoidal gourds having the local names of “ sand bullets,” “sand clams,” ete. These indurated phases are well developed at the Homestead sand pits near the old Pat- terson mansion in Baltimore City. A ferruginous oolite is occasionally found, especially in the vicinity of Washington, this phase recalling Tyson’s term “ Lower Oolite” for the deposit. The Patuxent sands are very varied in color, the most distinctive being purple, which is perhaps due to slight traces of manganese in the deposits. The clays of the Patuxent formation are much less important than the sands, with which they occur either as pellets or larger masses in the arkosic materials or in interbedded streaks and lenses which at times are of considerable extent. They commonly consist of kaolinized material of greater or less purity, and locally known as “ Fuller’s earth.” The clays are prevailingly white, but are at times of various delicate 60 Tue Lower Cretacrous Deposits oF MARYLAND shades of red, yellow, brown, maroon, and lavender, in piebald tints and patterns of great beauty. ‘The purple coloring is very characteristic. Extensive lenses of these brilliantly colored clays occur in the eastern part of the city of Baltimore, where they constitute an important re- source for the brick industry. They were penetrated to a depth of 40 feet in the excavations for the new outfall sewer for Baltimore City without reaching their base, and were so resistant as to require the almost constant use of the mattox. At Bayview these same clays were so resistant as to require blasting. The clays are at times drab or black in color, from the admixture of carbonaceous matter. Very definite beds of lignite occur at some points, notably near Jessups and at Clifton Park, at both of which points the lignite has been employed to some extent as a fuel, although the beds are rarely more than a foot in thickness and are of small horizontal extent. Lignitized twigs, limbs, and trunks always strongly compressed as well as fossil leaves are not uncommon in these deposits. Lignitized stumps have occasionally been found in erect positions. The comminuted carbonaceous matter is at times so abundant in the clays as to produce an earthy lignite of dead- black color. A deposit of this character filled with lignitized stems occurs in the valley of Broad Creek, Cecil County overlying the basal conglomerate before mentioned. Occasionally the drab or lignitized clays carry carbonate of iron as at Gaither’s Dam in Stony Run, Anne Arundel County, but the deposits are of small economic importance. Deposits of red and yellow hydrous oxide of iron are at times found in sufficient extent to possess economic value as pigments. Such deposits frequently occur at the top of sand beds which are overlaid by drab clays, as at the base of the terra cotta clays at Federal Hill. Strike, Dip, anp THicKnEss.—The strike of the Patuxent formation in Maryland is in a general northeast-southwest direction, becoming . more nearly north and south as the valley of the Potomac is reached, to the south of which, in Virginia, the strike is north and south. The dip of the beds is to the southeast but is variable in amount, espe- cially in proximity to the Fall-line, where in places it largely exceeds the dip of the main body of the deposits farther eastward. The dip to the MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE IV Fic. I.—VIEW SHOWING ERODED UPPER SURFACE OF THE PATUXENT OVERLAIN BY SUNDERLAND DEPOSITS, BELT LINE CUT NEAR CHARLES STREET, BALTIMORE CITY. Fic, 2.—VIEW SHOWING PATUXENT-ARUNDEL CONTACT, SOUTH SHORE OF SPRING GARDENS, THE PROBABLE LOCALITY WHERE TYSON COLLECTED THE HISTORIC JOHNS HOPKINS CYCAD STUMP, BALTIMORE COUNTY. MaryYLAND GEOLOGICAL SURVEY 61 east of the Fall-line varies from 50 to 90 feet in the mile, the average being about 60 feet in the mile. The rate of dips in feet per mile at various points is: FEET FEET FEET Burtonsville ....... 75 Perry Hall ........ 66 Battle Swamp ..... 13 Laurel 4 sessscieiceus 65 Loreley ............ 100 Throdors .......... 100 Ilchester Hill ..... 68 North of Joppa...60-80 Bay View ......... 90 Relay” .cacscencasss 200 Abingdon ......... 100 Egg Hill .......... 80 Catonsville ........ 114 Harford Furnace... 70 Cherry Hill........ 60 House of Refuge.... 75 Carsins ........... 100 Barksdale ......... 45 Baltimore ........ 80-90 Aberdeen ......... 109 Grays Hill ........ 50 Towson ........... 66 Aldino ............ 100 Iron Hill .......... 50 -Cub Hill .......... 58 Webster ........... 100 Chestnut Hill, Del.. 50 The altitude of the Patuxent beds in the Lutherville area previously mentioned is anomalous, for besides lying at.a lower level than the de- posits farther to the seaward the dip is slightly to the northwestward. From the above facts it is apparent that the deposits near the Fall- line have been subjected to greater deformation than the beds farther eastward, still in no instance is there any certain evidence of actual faulting along this line, although the high angle of dip at Relay, the elevated position of the beds at Catonsville, and the abnormal altitude of the strata at Lutherville, all point to unusual structural conditions that may find their explanation in the faulting of the strata. The maximum thickness of the Patuxent formation in Maryland is not less than 350 feet and may considerably exceed that amount. In the well boring at Indian Head it has been penetrated for a thickness of 353 feet without reaching the crystalline floor. In northern Virginia, at Alexandria, the brewery well shows 380 feet of Patuxent materials. Toward the landward margin of the Patuxent formation less thicknesses are found, the deposits frequently not exceeding 150 to 200 feet. A similar thinning of the formation occurs seaward, as shown by the deeper well borings in eastern Maryland and Virginia. STRATIGRAPHIC AND StRucTURAL ReLations.—The Patuxent forma- tion, as the basal formation of the Coastal Plain, rests directly on the crystalline rocks of the tilted and submerged margin of the Piedmont Plateau. This surface more or less eroded and trenched before the 62 THE Lower Cretaceous Deposits or MARYLAND deposition of Patuxent sediments has been elsewhere described as the Weverton peneplain. Monadnocks rise from its surface, as at Grays Hill, now surrounded by Potomac deposits. These underlying rocks in Maryland consist, as far as known, only of crystalline rocks of early Paleozoic and pre-Paleozoic age, although both farther north and south the Newark formation of Triassic age here and there reaches to the Coastal Plain border. The slope of this ancient surface which has been regarded as of late Jurassic or early Cretaceous age, is quite uniformly about 75 feet in the mile towards the southeast, although local differences occur due to the irregularities of the surface previously described. The Patuxent formation is sometimes irregularly overlain uncon- formably in Maryland by the Arundel formation, which apparently occu- pies post-Patuxent drainage lines that had been warped before the deposition of the Arundel sediments. Covering both formations un- conformably, and in the absence of the Arundel resting directly on the Patuxent formation, is the Patapsco formation, which in Virginia, where the Arundel formation is absent everywhere, comes in contact with the Patuxent formation. In the absence of both of these formations of the Potomac Group later formations of Upper Cretaceous, Tertiary and Qua- ternary age are found overlying the Patuxent deposits unconformably. The internal structure and stratigraphy of the Patuxent formation is at times very complex, more so than that of any of the other Coastal Plain formations. Contemporaneous erosion planes, very coarse and steeply inclined cross-bedding and alternations of extremely dissimilar and sharply demarked beds and lenses in irregular attitudes, although not the rule, are not at all uncommon. At times small folds occur in the beds in contact with the crystalline rocks which are apparently due to local expansions in the latter, as the result of their hydration. An interesting fold of this character is seen in the pits of the Maryland Clay Company at Northeast, Cecil County, as the result of the kaolinization of the feldspathic rocks. To what extent the beds have been subjected to larger structural changes cannot be readily determined. The abnormalities in dip in the vicinity of the Fall-line have been already referred to, and the possibility MaryLanp GroLocicaL SuRVEY 63 of faulting suggested, although no definite evidence on that point exists. It is evident, however, that a warping of the beds occurs whether with or without dislocation of the strata. The main body of the deposits may well have been subjected to deformation in the many differential move- ments which are known to have taken place in the Coastal Plain in post- Patuxent time. Furthermore, some of the marked changes in dip in the later formations, as notably in the Magothy formation along the line of the Chesapeake and Delaware Canal, suggest the possibility of actual folding of the underlying formations. Orcanic Remains.—Although the Patuxent deposits are in general unfossiliferous because of their coarse character, nevertheless a consider- able flora has been collected from clay balls and lenses and the more argillaceous sands, especially from beds of this age in the Rappahannock and James river valleys in Virginia. This flora includes a large element made up of survivors from the older Mesozoic, and is rich in species and individuals referred to the fern genera Cladophlebis and Onychiopsis. Other genera of ferns, such as Acrostichopteris, Schizeopsis, Scleropteris, Teniopteris, Ruffordia, etc., are less common. A variety of cycad remains testifies to the abundance of this type of plant, represented for the most part in the Maryland area by the silicified trunks of Cycadeoidea, of which several different species are known. Cycad fronds, less common in Maryland, are abundant in the more argillaceous deposits of this age in Virginia, and include a variety of genera such as Nilsonia, Podozamites, Zamites, Williamsonia, Ctenopteris, Qtenopsis, Ctenis, etc. Perhaps the most striking of these remains are the large forms of Nilsonia and the splendid fronds of Dioonites. Among the gymnosperms are species of Sphenolepsis, Batera, Brachy- phyllum, Frenelopsis, Nageiopsis, Arthrotaxopsis, Sequoia, and Cephalo- tazopsis. These are for the most part genera that range from the late Triassic to the Upper Cretaceous. They are abundant in the Patuxent and represent families which in the modern flora are largely natives of other continents. 5 64 THE Lower Creracrous Deposits oF MARYLAND Supposed, but altogether doubtful, angiosperms, the most ancient known, are represented by the genera Rogersia, Protewphyllum, and Ficophyllum, which perhaps should be considered the remains of foliage of the gymnospermous order Gnetales. The known fauna of the Patuxent is represented by a single fish found in the James River area, but it is extremely probable that the rich dinosaurian fauna of the overlying and closely related Arundel forma- tion flourished during Patuxent time, since in the west the representa- tives of this fauna occur in the Morrison formation conformably below the Kootanie formation, which carries the representatives of the Patux- ent flora. THE ARUNDEL FORMATION NamE and Synonymy.—The Arundel formation was named from Anne Arundel County, Maryland, where the deposits of this formation were first recognized as a distinct unit by Clark and Bibbins.’ It is the lower portion of the “ upper oolite,”’ or “ Iron-Ore Clays” of Tyson, a part of the “ Variegated Clays” of Fontaine, and McGee, and of the “ Baltimorean ” of Uhler, and is the equivalent of the “ Iron-Ore series ” of Ward. AREAL DistriputTion.—The Arundel formation outcrops in an irreg- ular and partially interrupted belt that extends from the head of Bush River, in Harford County, to Washington, D. C. This belt adjoins that of the Patuxent formation to the west, and reaches its maximum width of 7 miles in the northern portion of Prince George’s County, its usual width being from 3 to 5 miles. Where the formation is not overlain by later deposits it generally forms broad dome-shaped hills. The observed vertical range of the Arundel deposits is from 300 feet above tide to the landward to 368 feet below to the seaward. LirHotocic Cuaracrers.—The Arundel formation consists typically of drab, more or less lignitic clays, carrying nodules, geodes, flakes, and ledges of earthy iron carbonate or siderite. The nodules or geodes are 1 Loc. cit., p. 485. MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE V. Fic, I.—VIEW SHOWING INDURATED LEDGES IN THE PATUXENT FORMATION, W STREET NEAR I2TH STREET, WASHINGTON, D. C. Fic. 2.—VIEW SHOWING FLOODED IRON MINE IN THE ARUNDEL FORMATION NEAR MUIRKIRK. MaryYLanp GEoLogicaL SuRVEY 65 often septarian, and their cavities are commonly lined by brown velvety masses of siderite crystals, which change to brown hematite on exposure to the air. The materials of the Arundel formation are so strikingly homogeneous, as compared with those of the underlying Patuxent and overlying Patapsco, that its deposits have served as a datum plane for Potomac stratigraphy in Maryland, and the iron produced is prized for its high tensile strength. The clays are commonly free from grit, but are at times sandy, and to the landward the sand may predominate, as in the vicinity of Washing- ton. The clays are not infrequently pyritous and gypseous, both minerals commonly occurring in druses. The gypsum druses frequently line the septarian nodules but also occur free in the clays, as at Spring Gardens. The clays are in general unctuous or “ fat,” and are an important resource for brick, terra cotta, and pottery manufacture. They have been worked for these purposes at several points, but will undoubtedly be much more extensively employed in the future. The siderite deposits known locally as “ oolite ore” are changed com- monly at the surface, and in the clays poor in carbon to greater depths into hydrous oxide of iron or limonite,; known locally as “brown ore.” These ores have been mined since early Colonial days, one furnace at Muirkirk being still in operation. The lignitic element in the deposits, which gives to the clays their characteristic drab color, at times becomes so pronounced as to form well-defined lignite beds, which have been locally used as fuel, as at Soper Hall Hill, Anne Arundel County. The lignite is at times finely scattered through the clays, at other times trunks, limbs, twigs, and leaves are found well preserved, the stumps in some instances being found in erect position with their roots intact as they grew. At times the woody fibre may be partly replaced by siderite or by pyrite, as at Reynolds’ iron mine at Hanover. Strike, Dip aND TuickNess.—The strike of the Arundel formation is essentially parallel to that of the Patuxent toward the north, being about northeast to southwest and gradually becoming more nearly north and south as southern Maryland is reached. 66 Tue Lower Cretaceous Drposits oF MARYLAND The dip of the beds is to the southeast, arid is in general at the rate of about 50 feet in the mile. It is greater in the Fall-line zone, as shown in the Putty Hill, Carney, and Camp Chapel areas, and is less to the eastward. The observed thickness of the Arundel formation varies from a few feet to about 100 feet or perhaps 125 feet in the middle of the belt in central Maryland. It apparently thins seaward, as shown by the well boring at Sparrows Point. STRATIGRAPHIC AND STRucTURAL ReLations.—The Arundel forma- tion overlies the Patuxent formation unconformably, occupying what appear to be old drainage lines therein, but extending beyond these to the seaward where it spreads into a more or less continuous sheet. ‘The formation rarely comes in contact with the crystalline rocks, but a few instances are known, as at one locality north of Relay and in the Camp Chapel area. The deposits are unconformably overlain by the Patapsco formation, or in the absence of the latter by the later Tertiary and Quaternary formations. The internal stratigraphic and structural features are relatively simple, the strata consisting for the most part of widely extended beds or lenses of clay with included beds of lignite and iron ore. Some cross-bedding is found in the basal beds landward but it is unusual. The strata give evidence of deformation similar to the Patuxent beds in the Fall-line zone, and are likewise affected by the general warping of the underlying Patuxent previously described. Oreanic Remains.—Both animal and plant remains occur in the Arundel, its manner of deposition favoring the preservation of both. The Arundel fauna represents, so far as known, three orders: Dino- sauria, Crocodilia, and Testudinata. The dinosaurs represent all of the sub-orders, including two of the heavier, megalosaurian carnivores, Allosaurus and Creosaurus, and one of the lighter, compsognathus type, Celurus. The quadrupedal Sau- ropoda are represented by at least one genus, possibly two, Pleurocelus and Astrodon, including two or three species in all, while. of the Orthop- MARYLAND GEOLOGICAL SURVEY 67 oda there are two, one the unarmored Dryosaurus, the other, Priconodon, evidently belonging to the armored group or Stegosauria. The dinosaurs show none of the remarkable over-specialization of the later types, but, on the contrary, represent the order at the crest of the evolutionary wave, before the signs of decadence set in. Unfortunately, owing to an almost utter dearth of terrestrial Jurassic deposits, nothing is known of dinosaurian evolution in America from Newark time until we come to the horizon under consideration. In Europe the record, though still meagre, is more complete; but it represents in every instance more primitive types than those of the Potomac and the Morrison. The flora is of the same type as that of the Patuxent, most of the genera and a large number of the species of the latter having been found in the Arundel and where unknown the presumption is strong that they still existed in nearby areas, since the known Arundel flora contains no new or younger elements than does the Patuxent, and indi- cates that the marked change in the flora of the Potomac occurred during the time interval represented by the unconformity between the Arundel and the overlying Patapsco formation. The Arundel formation also contains poorly preserved representatives of fresh-water molluscs. THE PATAPSCO FORMATION Name anp Synonymy.—-The Patapsco formation was named by Clark and Bibbins* from the Patapsco River in Maryland, in the drain- age basin of which stream the deposits are well exposed and were first studied as an independent formation. It was included by Rogers in his “Upper Secondary ” or “ Jurasso-Cretaceous ”; by Tyson together with the preceding formation in his “ Upper odlite.” It was with the Arundel included by McGee in his upper or “ varicolored” clay member. The formation was not differentiated either by Marsh, Fontaine, Ward, or Darton in their Potomac. It corresponds in part to what Fontaine termed the Baltimore beds, and includes Ward’s Mt. Vernon series and 1 Loc. cit., p. 489. 68 Tur Lower Cretaceous Deposits or MARYLAND part of his Aquia Creek series as well as what he also called the Brooke beds. AREAL Distripution.—The Patapsco formation outcrops in Maryland in a belt of varying width extending from the Delaware line southwest- ward to the District of Columbia to the east of the preceding formation. To the south of Washington it is found along the valley of the Potomac to below Mattawoman Creek. From the Delaware line to the District the belt has a width of about 5 miles, south of which it narrows appre- ciably until it finally disappears in Charles County, although continued on the west bank of the Potomac in Virginia. It is a much more con- tinuous belt than the preceding Arundel formation. Outliers are found resting on the Patuxent formation. The surface is rolling, resistant caps frequently occurring as the result of the fer- truginous crusts which are often developed. The Patapsco deposits have been found all the way from hills 300 feet and more in elevation to a depth of about the same amount in well borings. Lirnotocic CHaracrers.—The Patapsco formation consists of sands and clays which differ, however, from those of the Patuxent formation in the predominance of the argillaceous elements, especially the varie- gated clays. The arkosic sands and gravels are much less common than in the Patuxent formation. They are more common toward the southern part of the area, where they at times become indurated, forming a part of the well-known “ Virginia freestone” of the Aquia Creek area. A band of pebbles frequently marks the base of the formation, as in the Hanover region. A bed of broken and redeposited ironstone crusts may take the place of the pebbles, as near Hawkins Point on the Patapsco River. The most characteristic materials are the highly colored and varie- gated clays with their red, drab, and chocolate colors. The clays often grade into or are interbedded with sandy clays, sands, and gravelly sands. They are at times lignitic, a typical illustration being the lignitic sandy clay at Fort Foote. Pellets of fossil resin at times occur with the MARYLAND GEOLOGICAL SURVEY. & he LOWER CRETACEOUS, PLATE VI. Fic. I.—VIEW SHOWING THE PATUXENT-ARUNDEL CONTACT 1N BELT LINE CUT NEAR THE EASTERN BOUNDARY OF BALTIMORE CITY. Fic. 2.—VIEW SHOWING EROSION OF OLD IRON MINE IN THE ARUNDEL FORMATION, SCHOOLHOUSE HILL, BALTIMORE COUNTY. Marytanp GEOLOGICAL SuRVEY 69 lignites. Small deposits of pyrite are also found in the same beds. The variegated clays which commonly exhibit a great variety of exception- ally rich and delicate tints in irregular patterns often grade hori- zontally into massive drab and black clays, which are often lignitic and occasionally iron- or leaf-bearing. The sand sometimes contains pellets or balls of white clay. They are frequently cross-bedded, although not as strongly so as the sands in the Patuxent formation. Red ochre, known as “paint rock” or “paint stone,” occurs near the base and summit, and sometimes within the formation, while flakes of sandy and ocherous limonite with botryoidal inferior surfaces are not uncommon at certain horizons. The variegated clays often contain small pieces of flattened limonite quite uniform in size. The drab and chocolate-colored clays have been worked at some points for iron carbonate in the Middle River region, but the amount of ironstone is small compared with that in the Arundel formation. Strike, Dip, anp Tuickness.—The strike of the Patapsco formation is essentially the same as that of the two preceding formations. The direction changes slightly due to the structural features involved in the central portion of the area by which the Patapsco formation gradually transgresses the earlier formations, both toward the north and toward the south, which slightly affects the direction of the strike in the same areas. The dip is to the eastward at the rate of about 40 feet in the mile, although it is somewhat increased within the Fall-line zone. The thick- ness of the Patapsco formation is somewhat in excess of 200 feet, the maximum thickness being observed in a’ well boring at Bowie, near the Raritan-Patapsco contact, where a thickness of 260 feet was found. The wells at Sparrows Point show a thickness of 204 feet, but it is pos- sible that the upper beds had been eroded before the Pleistocene deposits were laid down. At Red Hill, Cecil County, a thickness of 130 feet has been observed, while at Grays Hill, in the same county, it reaches 100 feet. 70 Tue Lower Cretaceous Derosits oF MaryLAND STRATIGRAPHIC AND STRUCTURAL RELATIONS.—The Patapsco forma- tion rests unconformably on the underlying formations and at the 340- foot hill at Relay transgresses them and rests on the crystalline rocks. Toward the north the Patapsco deposits gradually transgress the underlying formation, and in Delaware and Pennsylvania rest di- rectly on the crystalline rocks at a number of points. Monadnocks of crystalline rock penetrate the Potomac formations at several points in northeastern Maryland and the adjoining portion of Delaware. The Patapsco formation was much eroded prior to the deposition of the Raritan, so that marked irregularities are found in the line of con- tact which represent rather pronounced inequalities in the upper surface of the Patapsco. In general the line was well defined, and at some points is marked by a line of broken and redeposited iron crusts. In the ab- sence of the Raritan, which gradually thins out towards the south, the Patapsco formation is overlain unconformably by later Cretaceous or Eocene deposits, while in the absence of both later Cretaceous and Ter- tiary deposits, the Patapsco formation is often overlain unconformably by Pleistocene deposits. The internal stratigraphy and structure of the Patapsco formation is somewhat complex, on account of the great difference in the character of the materials, ranging, as they do, from very plastic and highly variegated clays to coarse sands, the latter occurring in lenses and beds which at times considerably complicate the stratigraphy, although they are not sufficiently continuous to make it possible to subdivide the Patapsco into members of more than local importance. Such local lithologic terms have been employed by others, but the very circumscribed limits of these beds render their use very problematical. Some warping of the beds evidently occurs along the Fall-line, as shown by the differences in dip, and it is quite possible that actual faults occur, although on account of this continuity of the strata and their frequent cover of later deposits it is impossible to determine this point definitely. As already pointed out, the marked changes in dip MarRYLAND GEOLOGICAL SURVEY "1 seen in some of the later formations, and particularly the Magothy for- mation along the line of the Chesapeake and Delaware Canal, suggest the possibility of actual folding in the Patapsco and earlier formations. Organic Remains.—The Patapsco deposits have yielded a few speci- mens of poorly preserved unios and an extensive flora, including repre- sentatives of the Pteridophyta, Cycadophyte, Gymnosperme, and Angiosperme. The ferns, cycads,. and conifers represent for the most part the dwindling remnants of the Patuxent-Arundel flora, some species being common to all three formations and the genera being largely identical. The fern genera Scleropteris, Schizeopsis and Ten- opterits have disappeared, but Ruffordia, Cladophlebis, and Onychiopsis are still common. Petrified remains of a species of Tempskya and im- pressions of fronds of a peculiar new genus of ferns, Knowltonella, are highly characteristic of this formation. Among the cycads Podozamites and Zamites are represented, but the genera Nilsonia, Dioonites, Ctenis, Ctenopteris, and Ctenopsis have disappeared. Silicified trunks of Cyca- deoidea have been found in the Patapsco, but it is questionable if they have not been reworked from the older formations. Among the gymnosperms Laricopsis, Baiera, Cephalotacopsis, and Arthrotaxopsis are no longer represented.” Species of Widdringtonites and Pinus are new and characteristic, while the genera Sequoia, Spheno- lepis, Brachyphyllum, and Nageiopsis are still present. The marked distinctness and more modern aspect of the Patapsco flora is due, however, to the abundance of Dicotyledone, which fore- shadow and were undoubtedly for the most part ancestral to the Dicotyled- one of the Upper Cretaceous Raritan formation. The more characteristic of these are the various species of Aralia- ephyllum, Sterculia, Cissites, Celastrophyllum, Populophyllum, etc. The compound leaves of Sapindopsis are one of the most striking dicotyledo- nous elements present. Three species are known and all are strictly confined to this horizon. ! 72 Tre Lower Cretaceous Deposits oF MARYLAND LOCAL SECTIONS I. Section at “ Red Hill,” along the west slope of Gray’s Hill, Cecil County, beginning at 200 feet above tide. Feet. Cretaceous. Coarse reddish sand and evenly-bedded dark brown Raritan ... sandstone ledge .......... cece cece eee cnet eee e reese 10 Yellow and buff sand and corrugated iron stone....... 10 Tough white clay reddish in places..... amie pa aie eesti qT Patapsco ....Massive variegated red and drab clay, the latter slightly lignitic and containing obscure leaf im- pressions. Lenses of white, water-bearing sand near DASE: iv sreaiace acaua. Srecn dedi aareia-s ewer ds sed FeO ETM at ee 130 Patuxent ...Sand, not exposed at surface, to tide level............. 43 TOtal nd ca deaeaaiakiaee hide Ga eae see aac sews 4 200 II. Shannon Hill near Northeast, Cecil County. ! Pleistocene or Feet. Recent ....... Loam and’ red Clays so: ccc acct esses sidad os eae ares ee eee 5-10 Cretaceous. Raritan ....Dense plastic chocolate colored clay with flakes of iron carbonate carrying leaf impressions. to bidet Laval guajsaveScusiew Light colored sand..................4. te ee et 8 Sandy chocolate colored clay.............cceeeeeeeeee 10 Drab and light colored clay and sand grading into West MCMbE? 40.5 -ssac ge eas yes eee seen SESE ae DERE Patapsco ..4 Chocolate clay, slightly lignitic..............c.ccceeee 7 Variegated clay: s6iss00 .cisawetiawe csaawes ea eeee bas ae 18 TWEE Gp SQM co soas snesis ane apne a, ooberis Dates nveyenclateee hum Se ayeiia. ous aug 1 VariGZated ClAY™ issn ecckcate 8 soatdeatace@daswerd Wome Mew a ace 35 Yellow and purple sand and ferruginous sandstone. . 5 Total: 422 +s0s64nee0s0Ge tase yeas ee Reese Se SRO 112 Ill. Section of Baltimore and Ohio Railway cutting at Foy’s Hill, Cecil County, beginning 270 feet above tide. Feet. Recent .........Gravelly loam-“ wash” ........... ccc cece ee ceeces - 6 Cretaceous. HinG: white. sand 2ais.c4036 450s yeh sas ws Bees w 11 Brown loamy sand, more or less gravelly and arkosic toward DAC: sess cscs dé gies Fo Sine ee ieee ene s wesc ae 12 Raritan ..~ White chinaware clay, more or less iron tinted, and varicolored, at times grading horizontally and ver- tically into micaceous sand and becoming gravelly and arkosic toward the base.......... eee cece e es 10-20 Patapsco .... Very dense, richly variegated clay, to and below the track: (Evel! cscs asus gases eawe ened ia sew MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE VII. Fic. I.—VIEW SHOWING'EROSION OF ARUNDEL CLAYS, HARTKE IRON MINE NEAR HANOVER, HOWARD COUNTY. Fic. 2.—VIEW SHOWING REYNOLDS IRON MINE IN THE ARUNDEL FORMATION, I MILE SOUTH OF HANOVER, ANNE ARUNDEL COUNTY. MaryYLANp GEoLoGicaL SuRVEY "3 IV. Well Section at Sparrows Point, Baltimore County, Well No. 4, beginning 10 feet above tide. Feet. Inches. Recent ......... Artificial, fH) sje esd ecnca seats s e886 has shed 10 Pleistocene. Medium coarse buff sand..............02 sees 12 Talbot .... 2 Coarse light drab sand.................2 sense 53 Drab calcareous clay, with remains of marine INLVOLCEDPATES: —sousss-crecsstewaleiacdon os eneeeny oe eon 5 20 Cretaceous. (Light colored plastic clay..................6- 22 Very coarse gravel.......... cece eee ee ere eee 23 "WHite BANG: oss w,ceiaced databace ed panaleve seein ere 5 HYUM@ SAVED assis oi ve aiae ban te “a joes eo sig 8S cvteee oceehs 5 Hard brown Clay ais. sissies nes oe see oa ae 15 Fine buff sand =. :. ccc scscacsaecvessecs neee vss 13 Fine white water-bearing sand................ 32 Very coarse gravel......... cece eee ee cee eee 8 Hard sticky fine red clay............-......65 32 Patapsco ..~ Coarse water-bearing sand...............000+ 12 Data from the neighboring coke oven well earries the section beyond this point. Begin- ning at 220 feet from surface, near base of the foregoing member. ROG: Clay iiasiediie cies tian assed st eke 62 White sand ........ 2. cece cee eee eee eneneee 9 Red clay ...... Naciiiehs teeter a olattint ar afinestins: a anaua elds 4 ard San dh +56 5s son duet seduces ea antes cea eg: aerate 5 Tough. red. Clays siacsnensd ase esied case ee cows 4 Arundel (?), “ Flint rock” (probably iron carbonate)...... 0 3% | Soft blue clay, iron nodules at one level...... 23 85% Gray Sand: s:.66. cs dere satdah sos Wamng.es Nee es 21 Patuxent - J) Red clay ......... ccc ccc e eee e ence eee enenee 6 6 Unknow, osc agencies cee vse eases oes saewe ss we 71 Crystalline rocks.Granite at ........... 2c cece cece e eee eees 495 V. Section of Baltimore and Ohio Railway cutting east of Bay View Station, Baltimore County, beginning at 130 feet above tide. e Cretaceous. ; . Feet. Patapsco (?).Buff, ferruginous sands, often indurated and capping Ph Se NICO De eeisa Ssaeas eevenesd + Arcee Vise Seatco aka AS 10-20 Arundel ....Drab stratified leaf-bearing clays, occupying a depres- sion in the surface of the Patuxent’............... 0-15 White and varicolored, more or less indurated, cross Patuxent . bedded sands and gravels, somewhat argillaceous and with lenses of sandy clay to the level of the railway MDAC ~ hse cc crates egtvin AG wre bis waneie ed wade iw. Scudl ia, auton ws dealers "| Total se ea yates a ee save a ge OR Oe Re S 53 1See list of species in Tables of Distribution. 4 Tur Lower Cretaceous Deposits or MARYLAND VI. Section of Belt Line cut near Eastern boundary, Baltimore City, beginning 180 feet above tide. Pleistocene, : Feet. Sunderland .Brown more or less gravelly loam, at times with re- worked iron crusts. Occasional loose ferruginous sandstone masses at base........... cece ere ee eeeeee 20 Cretaceous. Patapsco ...Hard, irregularly bedded, buff sand with thin corru- gated plates of iron sandstone toward the eastward.. 0-15 Arundel ....Mostly massive dark red, yellow or mottled clay some- what sandy, locally wanting................00e eee 0-20 White and varicolored, often micaceous and cross pedded sand and sandy clay, with crusts and ledges Patuxent ..J of sandy mammalary limonite near the top.......... Coarse white sandy micaceous gravel, locally indurated toward summit by hydrous iron oxide, exposed... .10-20 Total. saciscatcianatand. stent ees ae meee es 95 VII. Well section at “ Smith’s Distillery,” Baltimore. Tyson published in 1860 a record of strata penetrated by this well on North- west harbor, which presents a typical Patuxent section. The well began at 10 feet above tide. Feet Recent ......... RAVER MG sec aha ieisvcisteus aes ads nesses nance ance acaivaew aunenaen @ mcuayaeenatn 52 Cretaceous. Sand, gravel and boulders............... 000. c cee eeeee 6 ard, DIME) CLAY i sscssets witesecs, wis Sage area alge tae ee see senegtow saath 9 ROG CLAY cicoacacns eiegtbeniveara we anos pute aoe Hane SATE RUE Nie 6 Patuxent ..,1Red OCher .sincsenceaseasiws wrens vee saver ns seer sawn 5 White: sand) s 95 scssseeus nies cacnes deals sewed nase eae 4 WHICH] OY: scaicasia. sist ausis aieckpewe: chave Spmeadsdtuerseand studecuae Sl aunsne 32 White sand and gravel, water-bearing................. 8 White sand, gravel and boulders, water-bearing....... 7 Crystallities”.c2. (Gnei8S scene sarsa cea ve ater k ou hoes ane amtacseo ais 7 Total: cicwocers come neges sea exec see eae eres 129 VHI. Well section at Torsch Packing Company, Chesapeake Wharf, Baltimore, beginning 10 feet above. tide. Sisti Feet. O1IS: ‘iiakins-vkeunicira dle aaa areaes umount aha euch etalant eine Recent ........ {awa cis fos aaah alana Shae as ser iet Seal eed taina uence RNAS A ioanacneee 6 . Mud with shells and gravél............ 0... ccc cee caeee 7 Cretaceous. FROG: CRY cassie ew at arattarncia pesca aya Aaseceesasnovghayd seas eaeacdh caravaee 8 Whe Clay® sieges: scar pisieco oie See i secen casa oe ies vine dua -dv'u Wheaaeee lees 15 Sandy white clay........... 0c... ccc cece ec eeceeceues 15 Patuxent . {Sand rock .........ccc cece ceceecececeteceeecec ee. 5 Impervious white clay............ccccesccuccactecces 15 Water-bearing white sand...............ccccaeceecaee 22 Estimated to bed rock............ ccc cece cee canees 48 MARYLAND GEOLOGICAL SURVEY: 5 IX. Section at Federal Hill, Baltimore, at Baltimore Terra Cotta Works, Covington and Ostend Streets and beginning about 70 feet above tide. Feet. Inches. Cretaceous. (Sandy clay, sand and ferruginous sandstone, with silicified wood and red clay laminae... 5 10 Carbonaceous clay with flakes of white and Drown iron OF€...... cece cece eee eeee 1 4 “Alum clay,” “yellow horse clay,’ yellow ochre, and variegated clay, at times sandy and containing iron crusts and tubes........ 34 6 Bluish clay and potters clay with semi-erect Patapsco ...} stumps and horizontal logs of lignite, im- pregnated with pyrite. Occasional fern im- PPOSSIONS? cology ds ames atoms ea ciee eee £8 OS 7 6 Darker blue slaty clay, without fossils........ 3 Gray slaty clay, with profusion of plant re- TAINS) i525 cease og cuss 2G dykeks ae Be tiasies Geese RW eee ae 2 DANCY CLAY” rac sce nsnd a ds al ercsvaag a arene geeteing Bases 2 | Indurated ferruginous layers................6 y% Commercial red ochre.............0 eee ee eaee (Iron sandstone ............c cece eee ceeeeees % White Sand. sisi goed Bates Ge et ae a Hele eo nine, 7 Fine white sand with white clay balls........ 4 Building sand and indurated gravel, near tide. 4 The well at the Torsch packing house carries Patuxent ..Jthis section downward (allowing for dip) as follows: WHITC ClAY. sisecs Sotienere candela sate aitue wea wee 15 Arenaceous white clay...................000. 15 Sand TOK sii ceviwa cwruere aw ais stn a wee ere ew whe 5 White impervious clay.................00000e 15 White water-bearing sand.................... 22 TOtalL ADOUL ssi. cc sein iwid ae Shae ated aes 145 X. Section at “ Lower Smith’s Banks,” 1 mile south of Hawkins Point, Anne Arundel County. Feet. Pleistocene. Talbot ...... Brown massive and stratified loam with a few well- rounded pebbles toward base............eceeeeeceee 6 Cretaceous. Variegated argillaceous sand and sandy clay, iron crusts toward and at base where there is a local UNCONTOPIUICY: saecece Gsverdrt Goede, wok MURS S aha Vaio Ries Rahs Bese 4-8 Extremely dense, massive and tough, richly variegated Patapsco ..| CIAYS ©... eee eects eee eee e nent rece ne neee ren eeees 20 Continued downward by an artesian well at Ft. Armi- stead, Hawkins Point, as follows: Pink: Sani. Clay so atzes cicinss arensin 3 yah. d Suais oye cneual avg menses aca caunts 40 Fine: Duff sans. sissies ecco ac eae Saisie Deere ae gps cies 20 White and buff mottled clay.............. eee ee eens 16 Total sced 2 sti eaowe £4 she Seae Rae wa S eRe YS SS eit 110 1See list of species in Tables of Distribution. 76 Tur Lower Cretaceous Deposits of MARYLAND Xl. Section at “ Deep Ditch,” Schoolhouse Hill, Baltimore County, beginning 2380 feet above tide. Cretaceous. Feet. Patapsco ...Argillaceous sand, more or less iron-stained, with variegated clay and ferruginous crusts; ash-colored, lignitic and somewhat indurated toward the base.... 10 Slightly indurated, ferruginous ledge, with leaf im- pressions and casts of ComeS.............ee.eeeeees 1 Arundel ...j Drab-colored clays, with beds of lignite and white and brown iron ore, containing occasional fern impres- sions; teeth and bones of dinosauria; basal ferru- | ginous ledge. Extensively mined for iron.......... 50 (Compact yellowish, reddish and variegated sand, lo- cally carbonaceous; brown clay containing flakes of iron ore (hydrous oxide); lead-colored clay with indeterminate fragments of plants; ferruginous sand- stone ledge with “ pipe ore” (corrugated iron stone), silicified trunks of Cycadeoidea marylandica (Font.) Patuxent ..4 Ward 2in. Sltts oes ease aeons eee tee eR Ea 30 Dense jointed clay of great variety and delicacy of tint, red, liver-colored, and white predominating; “ paint rock” (red ochre) and lenses of coarse hard sandy arkosic gravel with balls of white clay and silicified W000 4 i ee c ace craw be ree es La Sees ee Fea 20 Cross-bedded sand slightly carbonaceous.............. 10 “UNKNOWN, ADOUWE i sic cease eaeie sieltincn do iene oe sacks two Oe ae 30 Crystallines ....Gneiss, exposed near Arbutus................00cecaee otal tue c-sucancnaamnsiecsiaa-y sovsamartaes 34 ua etiatnts ee 151 XII. Section of ‘‘ Red Stone” Baltimore and Ohio Railway cutting near Lans- downe, Baltimore County, 140 feet above tide. Cretaceous. Feet. Arundel ....Drab clays, iron-bearing in the immediate vicinity.... 10 Patuxent ...Buff, white and richly iron-tinted sand and clay (the sands at times indurated by iron) white “ pipe clay ” ANG: red! OCHLE:. o.ccsa 5 wie des sass ee idee ace ce bs ave ale ems bad 30 Ota inf ei caneea vamkas cave abet cat eae ees 40 XIII. Section at Reynolds’ Iron Mine, Piney Run, 1 mile south of Hanover, Anne Arundel County, beginning 100 feet above tide. Feet. Inches. Cretaceous. White and light brown sand and gravel with iron stone crustS..............cccee cee euee 10 Patapsco ... White and variegated argillaceous sand, clay and red paint clay, more or less indurated AU DESC se es teiquvas stamens ramea ea ansie oe ees) Scehde 10 Ferruginous ledge more or less conglomeritic. . 3 Arundel ...... Dense drab laminated clay, at times lignitic and with occasional undeterminable fern impressions. Nodules, flakes and ledges of carbonate of iron in many courses (partly determined by boring)..................005 70 Total. asec xevesae tu gpoubvace wile aca eeia a weae = 90 oo MarYLAND GroLoGicaAL SURVEY 7 XIV. Section at “ Timberneck Iron Mine” on Licking Run, 1 mile southwest of Hanover, Howard County, 200 feet above tide. Feet. Cretaceous. Reddish sand somewhat gravelly with corrugated iron Patapsco : SANdStONe seeccsvscsiasevs see vs seecs ws eae gue mokins 12 Variegated argillaceous sand and compact sandy clay { with clay pelletS........... cece eect eee eee is Sah 20 Arundel ...... Drab lignitic and at times pyritous clay, very dense, and carrying pellets, nodules, flakes and ledges of iron carbonate to bed of Licking Run............... 100 Patuxent .... White clay, exposed in bed of Licking Run............. 5 Total. cade saaiene eran aap bawatae eee besoin SES 137 XV. Section at Baltimore and Ohio Railway cutting, between Jessup’s and Montevideo Stations, beginning 290 feet above tide. Pleistocene. Feet. Sunderland .Loam, gravelly loam and ferruginous conglomerate grading into sand and gravel at the base.......... 0-15 Cretaceous. Brownish drab clay with fragmental masses of hema- titie ochre carrying leaf and cone impressions... 2-6 Patapsco ..J Light colored clay, grading over into red and varie- Pate) CLAY ks sas eee euihe- es eas Vee eiene: wipe lies Vlg Bewiie ialaieners 6 6+ Boe? Iron OTs «saree skews wakes ee ase gene ee eae s 1 Gravel .iccciacssandina ded ea wees eee eye asa ed ares ees 3 Lignitic clay, carrying iron carbonate and dinosaur- Arundel ... TAM DONES: asa gsceceeecc suse ceeseed a nano Sone tena ee ees 60 Light drab clay with “ white ore” containing occa- sional casts of mollusca.............. cece ee eens 10 Patuxent ...Generally loosely-bedded, white and vari-colored sand, argillaceous gravelly and arkosic sand and sandy clay, with much interbedded lignite to and below level of railway tracks.............0c eee eee eee 60 XVI. Section at “Old Blue Bank” iron mine, near Muirkirk, Prince George’s County, 230 feet above tide. Feet ReCeiits + ss02s nee Surface wash consisting of sandy gravel............ 4 Cretaceous. - Patapsco ...Mottled gravelly loam with silicified wood........... 12 Massive drab clay with septarian nodules of earthy Arundel ...2 siderite; bones of dinosauria near the base........ Highly lignitic lense with white charcoal ore...... ss 68 (Tough blue clay with white ore.................0.5 15 Patuxent ...White sand, exposed by boring................0e00- 10+- Total tHiCkiess, -sassccss.aphteck scayecsiese dere Gone e ares Bary 63+ 78 THE Lower Cretaceous Deposits oF MARYLAND XVII. Section at Florida Avenue and Sixteenth Street, Washington, D. C., beginning at 180 feet above tide. Feet Pliocene (?). Red loam, gravelly loam and gravel with cobbles and boulders toward base............cc eee ee ee eee eens 8 Lafayette Reddish brown stratified loam, vari-colored loam and c clay interlaminated with brown sand............... 10 Ferruginous gravel with boulders of crystalline and Newark: -TOCKS siisscsnaiasearwraa tied a duwnaa Gein aceaiew 10 Cretaceous. Arkosic cross-bedded pebbly sand with clay pellets, Patuxent slightly carbonaceous in places................0000: 15 Light greenish drab sandy clay...............ceceeeee 6 Total, «see004 ccaow sad nce eee at aie Roe ye dae aE 49 XVIII. Weill section at Pumping Station at Soldier’s Home, Washington, D. C., beginning 200 feet above tide. Feet. Cretaceous. pRed Clay es2ccsesesevemareoeed Benes nee aesaaNEts 2 Red ieravel) 7 lees sandy clay, with greenish-drab, chloritic, sandy Clay at tide... . cc. cece cece cece cece rene ener teens 55 Total - cigeucavens Santer Siam eines canoe isdn ds SEAM 97 XXIII. Section on Stump Neck, Charles County. Pleistocene. Feet. Talbot ...... Brown gravelly loam........... cece eee cece eee erene 3 Sand, gravel and cobbles............eeceeee rar encees 12 Cretaceous. tase eee compact sand slightly arkosic........... 8 Patapsco Massive green chloritic clay to tide, with lenses of drab clay carrying leaf impressions?..............-..-008 4 TOCA cocoetscave yest a ze pes Sears cae Go rad Se eee oe 27 INTERPRETATION OF THE POTOMAC DEPOSITS Potomac deposition was probably preceded by extensive base-leveling of the eastern side of the continent, with accompanying widespread rock disintegration. Stimulated by elevation and seaward tilting, the re- vived streams transported these materials to their present position. The fact that these deposits consist very largely of redeposited Piedmont crystallines, and to a less extent of Appalachian strata, is what might be expected, but the circumstance that no clearly defined trace of re- deposited Newark materials has been found in the Potomac deposits of Maryland is somewhat surprising. From this we must infer either that the Newark was not to any great extent exposed to Potomac erosion, or that its materials wére not sufficiently consolidated to permit of trans- portation, except in so finely divided a condition as to be unrecognizable. It is quite certain that during maximum Potomac subsidence a large body of Newark materials, especially beyond the limits of Maryland, was beneath tide level, and therefore not exposed to subaérial influences. Inasmuch as the Potomac beds themselves, particularly the basal ones, have since that date undergone considerable induration, often without 1See list of species in Tables of Distribution. MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE VIII. NEAR VIEW OF LAYERS OF CARBONATE OF IRON NODULES IN THE ARUNDEL CLAYS, REYNOLDS IRON MINE, I MILE SOUTH OF HANOVER, ANNE ARUNDEL COUNTY. MARYLAND GEOLOGICAL SURVEY 81 the agency of iron oxide, we may suppose that the subaérial Newark . sandstones of that date, if consolidated at all, were considerably less resistant than, for example, during the early Pleistocene, in the deposits of which the Newark materials are abundantly represented. The basal deposits of the Potomac Group, produced by the initial warp- ing of the continental border and described as the Patuxent formation indicate in their arkosic character their proximity to the source of supply, which was the extensively disintegrated Piedmont crystallines. It is assumed that the Weverton peneplain, upon which the oldest known Coastal Plain sediments were deposited, extended as a land surface to the eastward of the present coast line. The epeirogenic movement, which stimulated erosion and inaugurated the Potomac cycle of deposition was undoubtedly a differential warping, with the focus near the present Fall-line. This may have resulted in the formation of a broad, shallow basin near or below sea level, from which the waters of the Atlantic Ocean were largely excluded. McGee has compared the Potomac deposi- tion with that of the present Gulf of California, although the lack of any evidence of an invertebrate fauna in the Patuxent formation renders such an interpretation unlikely. A gradual tilting of the coastal border of the Weverton peneplain would seem more nearly to explain the facts, since it is well known that sea coasts with an almost imperceptible gradient like that of the present west coast of the Floridian peninsula, show characters identical with those coasts which are separated from the open ocean by barriers in the form of reefs or sand bars. It seems probable that the inner marginal Patuxent beds, which alone are avail- able for study, were largely continental deposits made up of an ever- varying and complex combination of fluviatile, eolian, and lacustrine sediments which merged in passing to the eastward with estuarine or littoral sediments. The well-rounded and rarely flattened pebbles are characteristic of fluviatile action, as is the presence of cobbles, often of large size, which are so prominent in some of the Virginia outcrops. The cross-bedding of so much of the arenaceous materials which pass horizontally into clay lenses and which contain rolled clay balls is also especially characteristic of fluviatile forces, and wolian forces may like- 82 Tue Lowrr Cretaceous Deposits oF MaryYLAND wise be called upon to explain cross-bedding, although it would seem that the latter class of deposits are practically negligible when the materials are considered as a whole. The quickened streams at the inauguration of the Patuxent built out alluvial fans with comparative rapidity and af- forded little opportunity for the preservation of terrestrial vegetation or of the aquatic life of the Patuxent rivers or lakes. The fossil plants which are so sparingly distributed in the Patuxent represent for the most part fragments of coniferous stems or coriaceous bits of foliage which successfully resisted the trituration of the coarse sediments. Only one Patuxent exposure, that at Fredericksburg, Virginia, has furnished an extensive flora, and this was contained in a single somewhat more argil- laceous lens of very limited extent. Elsewhere a considerable flora has been found in redeposited masses or balls of purer clay, which were evidently transported from their original place of deposition in the quiet waters of some Weverton oxbow or lake, and therefore antedate in their origin and their contained flora that which was contemporaneous with their final deposition in the Patuxent sands. That the contained flora is not appreciably different from that of the balance of the Patuxent flora indicates that this time interval, while long according to human standards, was short when measured in terms of genlogical processes. Such meagre fragments of the aquatic life of the Arundel and Patapsco epochs as are preserved, a few almost undeterminable fresh-water gastro- pods, tiny pelecypods and unios, indicate that conditions similar to those outlined above persisted until the close of the Potomac. The Patuxent deposits, like those of the succeeding Arundel and Patapsco formations, reflect in a large measure the: character of the Piedmont materials which lie immediately to the westward. Where these materials were highly feldspathic the sediments are strongly arkosic. This is a very characteristic feature of the Patuxent deposits, and one which continues unchanged as far as eastern Alabama, a distance of several hundred miles. Where gabbros or other rocks rich in the iron minerals are found near the eastern margin of the Piedmont, as in the vicinity of Baltimore, the derived sediments are ferruginous, and this is especially noticeable in the concentration of the iron in the Arundel MARYLAND GEOLOGICAL SURVEY 83 formation, and to a less extent in the Patapsco. Where the chloritic schists of the Piedmont are developed near its eastern margin, as in the northern Virginia area, the Patuxent clay lenses tend to be greenish in color. The close of the Patuxent epoch was probably marked by a slight elevation of its deposits and a trenching of the surface by streams; or perhaps the process was merely one of differential warping. This was followed by a subsidence or tilting, which was emphasized to the land- ward by the occupation of the ancient valleys by swamp deposits. The tough clays of the Arundel formation, charged with lignitic accumula- tions, in which tree trunks are at times found erect with their roots in- tact, find their most satisfactory explanation on this basis. It was in these ancient swamps and estuary marshes that the iron, derived to a considerable extent from the adjacent areas of basic eruptives, was de- posited, first, no doubt, as bog ore, which by contact with the excess of carbonaceous materials was later altered to the carbonate and redeposited in its present nodular form. It was in these swamps that the remains of dinosauria became entombed. On this hypothesis the lenses of Arun- del clays represent crudely the ancient drainage lines of the eroded sur- face of the Patuxent terrane. The widening of the areas seaward may possibly be interpreted on the basis of lagoon deposits into which the Arundel estuaries merged. The Pleistocene “ buried-forest ” deposits of the Chesapeake shores may furnish some clue to the origin of the Arundel iron-ore clays, as well as similar beds in the Patuxent and Patapsco formations. The Pleistocene deposits of this character appear to have originated by the impounding of the estuaries by sand spits—a process which may be ob- served at many points within the Chesapeake and elsewhere at the present day. The closed estuary then speedily silted up and was con- verted into a peaty cypress swamp in which bog iron ore was -deposited. Meanwhile the bay shore adjoining the mouth of the swampy estuary was gradually receding by virtue of wave action until the swamp mate- rials themselves were invaded and more or less cut away. This process was followed, or perchance attended, by gradual subsidence, which re- 84 Tue Lower Creracsous Deposits or MARYLAND sulted in the deposition on the newly wave-cut surface of a new and later member. Emergence followed, and the waves of the Recent period are now actively cutting away both the more recently deposited beds and the basal remnant of the older ones, with their beheaded cypress trunks and knees, imbedded in peat. In the basal clays of this Pleistocene swamp deposit, penetrated by the roots of the trees, one finds an occasional, im- perfectly formed nodule of iron carbonate, so characteristic of the Arun- del. When exposed to the air it rapidly changes to a bright vermilion ochre. There is little question that some such process as this has figured to a considerable extent in the genesis of certain of the lesser lenses of drab, lignitic, iron-bearing clay occurring at various horizons throughout the Potomac Group; but the large scale—both vertical and horizontal— on which the Arundel formation, or “iron-ore clays” proper, is de- veloped cannot well be explained entirely by this simple theory. Land- ward tilting must be retained as the chief explanation for the Arundel clays until a more satisfactory interpretation can be brought forward. The well-marked unconformity occurring at many points between the Arundel and Patapsco formations, notably in the West Hanover district, indicates emergence and a distinct erosion interval prior to Patapsco deposition, and the marked changes in the floras would seem to indicate that this interval was a long one, during which the Arundel sediments, if originally continuous, were removed by erosion from large areas. The ‘highly colored and variegated clays of the Patapsco formation, like the iron-bearing Arundel clays, evidently bear some relation to the great basic eruptive masses, plentifully iron-bearing, which lie to the north and west of them. This phase of the sedimentation is somewhat more prominent in central Maryland, where the rocks of this character are not only well developed, but nearest the eastern margin of the Pied- mont belt. It is also probable that these ferruginous Patapsco clays were also in part redeposited from the more richly iron-bearing clays of the subjacent Arundel. The Patapsco sands were doubtless derived to a considerable extent from those of the Patuxent terrane. That the seaward tilting was not continuous or persistent in the same MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE !X. Fic. 1.—VIEW SHOWING PATAPSCO SANDS OVERLYING ARUNDEL CLAYS, CEDAR HILL MINE, TIMBERNECK, I MILE SOUTHWEST OF HANOVER. Fic. 2,-VIEW SHOWING LEDGES OF INDURATED SAND IN THE PATAPSCO FORMATION WHICH IS OVERLAIN BY GREENSANDS OF THE AQUIA EOCENE IN CUT OF R. F. & P. RR, NEAR AQUIA CREEK, VIRGINIA, MarRYLAND GEOLOGICAL SURVEY 85 direction is evidenced by the varying character of the deposits and the statigraphic relations which the several formations sustain to each other. Jn the succeeding chapters the surface configuration, both of the crystalline floor and of the Potomac Group is discussed, and some pos- sible interpretations advanced. The greater thickness of the formations of the Potomac Group along a belt somewhat to the eastward of the Fall-line may have emphasized the downward movements in this portion of the Coastal Plain during Potomac time. On the other hand, the gradual removal of the weight over the Piedmont region by the removal of its residuals has possibly occasioned an upward movement of that area as well as of immediately adjacent Coastal Plain regions. The accumulating results of these ten- dencies, particularly the first mentioned, from the beginning of Potomac time until the present, have been the weakening of the crystalline floor near the landward border of the Coastal Plain, accompanied by monoclinal folding and even faulting on a limited scale. The studies of McGee in the upper Chesapeake area, and of others to the northward and south- ward, fully convinced him that displacement had actually occurred, al- though no very definite evidence was adduced in demonstration of the same. Other writers, including Fontaine, however, believe that we have to do merely with sedimentation across a pre-Potomac escarpment. In the opinion of the authors of this paper, the Fall-line phenomena in Maryland, and elsewhere, afford considerable evidence of actual dis- placements. A number of carefully constructed vertical sections on a large scale have been made across the Fall-line zone, and these show in nearly every instance evidence of this. Evidence of the actual displacement in the Potomac beds is very clearly defined in the vicinity of Relay, Maryland, and this is further strengthened by the fact that the Miocene beds at Catonsville, near by, lie considerably higher than the normal dip of the main body of: the Miocene deposits calls for. At the openings of the Maryland Clay Company, at Northeast, Mary- land, there occurs a well-defined example of an anticline in the Patuxent beds which is believed by Ries to have been produced by the hydration 86 Tur Lower Creraceous Deposits or MARYLAND of the subjacent feldspathic rock in the process of its decomposition into the residual kaolin mined at this point. ‘Though the scale on which the folding occurs is small, the phenomena afford a suggestion as to the possible causes of some of the lesser irregularities in the Patuxent beds which lie near the crystalline floor. Surface Configuration of Crystalline Floor and its relation to Potomac Basin of Deposition The basal beds of the Potomac Group rest on a more or less uneven surface of crystalline rocks, in which certain of the more important drainage lines of the present day were already established, as is shown both at the marginal contact and by the well borings near the landward border of the formations. The great increase in the dip of the Patuxent and succeeding forma- tions along the Fall-line has already been alluded to, as well as the evidence that it represents in part at least a fault scarp. It is significant, however, that there is a marked though less pro- nounced decline in the dip of the strata eastward of the Fall-line all the way to the seaward margin of the Coastal Plain. The evidence for this is furnished by the deep-well borings in-Delaware, Maryland, and Virginia, the number of which is not as great as could be desired, al- though they al] show, without exception, a progressively lessened dip of the beds as the distance from the landward margin increases. The following wells of the middle Atlantic slope reach the crystalline rocks and show the following rates of descent of the crystalline floor: Distance from point where crys- Depthofcrys- pate of " ; talline rock Location of well. talline rock surface below descent se oes tide level. per mile. Miles. Feet. Feet. Ice works, South Wolf Street, Baltimore ............-206- a 151 200 Baltimore Copper Works, Balti- MOLE: is gaa eehaes caggea nes 2 187 93.5 Farnhurst, Delaware ........... 2 111 55+ Middletown, Delaware ......... 12 452 37.7 Sandy Point, Virginia........... 2 270 185 Quantico, Virginia ............. 2 210 105 North End Point, Virginia...... 72 1,162 15.7 MarRYLAND GEOLOGICAL SURVEY 87 These records indicate a rapid slope near the Fall-line with a lessen- ing seaward, although actual elevation is suggested in the crystalline floor in the Middletown, Delaware, area, which may represent an exten- sion of an axis from Iron, Chestnut, and Grays hills to the southeastward. They also show an actual thinning of the Potomac deposits to the sea- ward, as shown by the well at North End Point, where the thickness of the Potomac beds is only one-half the normal thickness at the outcrop. The record of the well borings becomes of the highest significance when it is remembered that this crystalline surface has been receiving along its seaward margin progressively greater and greater loading through de- position since Potomac time. The conclusion is readily reached that subsidence took place gradually, and that any barriers which existed along the eastern margin of the Potomac basin were depressed below sea level. Marsh and McGee, as well as most other writers, have expressed their belief in such a barrier, although not adducing any further concrete evi- dence of the same than the non-marine character of the Potomac sedi- ments. McGee has suggested, as above stated, that a Potomac barrier may have been comparable in character and extent to the existing penin- sula of Lower California. Another possible, although perhaps less plausible, interpretation of these phenomena is found in the hypothesis of incipient folding in Potomac time. Such interpretations as have been suggested in the foregoing discussion may be understood as but an imperfect and more or less speculative at- tempt to reduce to language a long-continued series of events which in the actual complexities of the interacting factors involved baffles de- scription. Surface Configuration of Potomac Deposits and its Possible Interpretation The records of deep artesian well borings to the eastward of the Po- tomac belt indicate some clearly defined irregularities in the rate of decline of the Potomac surface. It will be seen from the following table that only a single record shows a greater decline than 25 feet, while 88 Tue Lower Cretaceous Deposits oF MARYLAND most of them show a descent much less than this amount, in one in- stance (Crisfield) even less than the observed average landward dip (124 feet) of the Eocene deposits which immediately overlie the Potomac beds to the southward. Distance from Rate of int whe Depth of : Location of well. maton’ © surface below Aeon surface reaches tide level. mile sea level. ° Miles, Feet. Feet. Rock Hall, Maryland............ q 240 34 Claiborne, Maryland ............ 19 440 23 Tunis Mills, Maryland......... 24 430 18 Tilghman’s Island, Maryland.... 27 400 15 Gloucester Court-House, Virginia 38 600 16 Williamsburg, Virginia ......... 38 550+ 14.5 North End Point, Virginia...... 62 920 15 Crisfield, Maryland ............ 91 964 10.6 According to these records, there is a marked lessening in the decline of the Potomac surface far to the seaward. When the surface of the Raritan formation is likewise considered there seems to be an actual rise in this surface in the Eastern Shore of Maryland and Delaware, between the Chester and Choptank rivers, although it again declines east- ward a little farther seaward, as shown by the boring at Gloucester Court House, Virginia. Whether we have to do with an erosional irregularity in the Potomac surface or with incipient deformation, the facts at hand do not permit us to determine. If the irregularity is due to the latter cause, the axis of the anticline would: not seem to be coincident with that of the peninsula of Delaware, but would cross the latter in a northeast- southwest direction. A depressed barrier, such as has above been indi- cated, may well have served as the seaward buttress in such deformation. Whether there may be more than one of these axial prominences in the Potomac surface is a question of much interest, but which cannot be answered with the data at hand. The lessening in the descent of the Potomac surface far to the seaward, as indicated by borings at North End Point and Crisfield, is in general in harmony with the relations of the subjacent crystalline floor above described. MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE X. Fic. I.—VIEW SHOWING MASSIVE VARIEGATED CLAY OF THE PATAPSCO FORMATION, NEAR HAWKINS POINT, ANNE ARUNDEL COUNTY. Fic. 2,—VIEW SHOWING PATAPSCO SANDS AND CLAYS OVERLAIN BY PLEISTOCENE SANDS, B, & O. R. R. CUT, ROSEDALE HILL, BALTIMORE COUNTY. MaryYLaNp GEoLocicaL SURVEY DISTRIBUTION OF THE FAUNA AND FLORA. The following tables show the geological and geographical distribution of the animal and plant remains which have been collected in the deposits of the Potomac Group both in the State of Maryland and in the contig- uous areas of the District of Columbia and Virginia. The species recorded in these tables will be fully described in subsequent chapters. 89 TABLE SHOWING THE DISTRIBUTION OF THE ANIMAL REMAINS. Patapsco. District of Columbia. Virginia. Near Muirkirk, Washington. White Rouse Bluff, DINOSAURIA. Allosaurus medius Creosaurus POteNns.....- +0000 Calurus Gracilis ....... crease Pleurocelus nanus........+-- Pleurocalus Altus...ccereee Astrodon Johnstont ...+.+ +66. Dryosaurus grandis...... 0.65 Priconodon crassus .......++ CROCODILIA. Goniopholis Affinis oo... sees GASTROPODA. Bythinia arundelensis......- Viviparus marylandicus .... Viviparus arlingtonensis .... PELECYPODA. Cyrena marylandica Unio potapscoensia........++- Arundel. Maryland. eae ow | O¢ ee oH a= ag ee ate | fee a a qe a eines snnienes we Iseestase: ’ aries o ate Vea gwen - bn aaa * venbeies| soeguass * aeaw ween |i9 t4 wees si ana The fossil plants which are much more abundant than the animal re- mains, are recorded in the tables which occupy the following six pages. All those occurring in the District of Columbia are listed as well as certain forms from the Potomac deposits of Virginia, although not all of the forms which have been found in the latter state are included. \A ~ Tempskya Whitei* Acrostichopteris expansa ..... Knowltonella Maxont ......... Dicksontopsis vernonensis Cladophlebis Cladophlebis Cladophlebis Cladophlebis Cladophlebis Cladophlebis Cladophlebis Cladophlebis Dryopterites Dryopterites Dryopterites Dryopterites Dryopterites dentata ..... Dryopterites virginica ...... Aspleniopteris rinnatifida Asplenionteris adiantifolia Onychiopsis latiloba Onychiopsis psilotoides ..... Onychiopsis brevifolia .. Onychiopsis Goeppertt Onychiopsis nervosa ..... Sagenopteris latifolia .... Sagenopteris elliptica ...... Sagenopteris virginiensis 90 Tur Lower Cretaceous Deposits oF MaryLaNnp PATUXENT DISTRICT MARYLAND OF VIRGINIA COLUMBIA e ms 3 eI ° : : 3 a : g 8 3\2 i + “4 a! S| 0] » Mie Bla|_|3| 2 e).(2/2/8/ 8] | ol5| | o| Ze) g/#)/3|8/3 S/S lelaie/%| |e gis] a) 8d BIOlS|~|S8l ple! Si/B/ely e| 21 /35| SlolSle ° SlalClFlsalalal Bl ale/s|/e Blais 3 Bitialsias|/oO]38 | o| Bl | 2] s] 9 al\fiz2 s/ele/6|./8|e/a|Slei3]s| 3) 3/3) 8/3] 8/3 ao | = o a ae Blala@lSjalel/sl2e|Sisisisjaaelelsalalar FILICALES Schizacopsis amertcand 2... ccveccvevceedevee ay |inival esas | desi ewe Ruffordia acrodentata ..cccevesscvcevceve jevee erica beesal| sl aha Ruffordia Goepperts wi cccccecvvcavcccvns feeteieres ie [eee g |e le Acrostichopteris cyclopteroides .......0.0 0 deoeefeeee sare ftovall ge | ois Acrostichopteris adtantifolid .. 11.0 cee ceca deresleees ig lasfoneleea Acrostichopteris parvifolia 1... 0 ccc cere ee deeweleeee « eale@ ls Acrostichopteris pluriparta oo. cc cece cne [eereleces Sa ssuoht met | ie Acrostichopteris longipennis . Psgecal lca Ovesal| wate Browniana . constricta virginiensis PATVA «sees Albertsii Ungeri .... Gistans ....eeseene macrocarpa .. Pinnatifida ...cesseeee cystopteroides elliptica . Taentopteris auriculata .. Taentopteris nervosa ...... Scleropteris elliptica ... Thinnfeldia Fontaine’ .........40.+ Thinnfeldia granulata ........ Thinnfeldia rotundiloba Thinnfeldia marylandica LYCOPODIALES Selaginella marylandica EQUISETALES Bquisetum Lyell .......4.. Equisetum Burchardti CYCADOPHYTAB Oycadeoidea marylandica? ........ Cycadeoidea Tysoniana .........00. TOtUNGATA woe eeceeueeee Peewee emcee ltteelenes a ne 1 Found eroded out of Patapsco formation along Dee ? This species occurs in situ in the Patuxent formation near Arbutus. Run and Stony Run and on Patuxent Neck. Localities for other species of 91 MARYLAND GEOLOGICAL SURVEY PATAPSCO VIRGINIA woj0og deeq 480d STTA-SL ayoorg yovlp Binby 18} BMOIPIM Sulpuey sayiyung AOTIOH ujdeyaIGO x1I0H IPH BuIA esnoy e1GM mouIeA “JN uUUl Yoop1aa9 Hoon duinyg quouls[y IBeN MARYLAND (BNA SIaysoy) 93007 WO ITH aeseuta ToSUyyseM “hd SUIBUTIOM (a1OMNTTBE) ITH (e1epad yoolp Appr quod 3aeidog IH 84819 ARUNDEL Viana HO LOIULSIG TOD peoy jedeqo susend> | uopsuey a[epszaaly HaPUIOT 9a}009 aUMOPSUBT m0SULIV JoAouUsH MARYLAND doL dha a1BIsy UMOIG PrBAoH aU Sploudsey aul suButses suUIW sqqoH areyeq AaTMog seleoel. 1leH sedog MoA Seq aouy} ed Cycadeoidea are not tabulated, since none have been found which have not been reworked into younger deposits. 92 Tue Lower Cretaceous Deposits oF MARYLAND PATUXENT DISTRICT MARYLAND oF VIRGINIA CoLUMBIA co | 5 a g i) —_ a) x 3 =. - 2 n 4 = LS © a B a 8 g 3/8 + a pe} 8 | to] 2] g bo alt bo} wy = ° ei 2ials 3 3o| o alg a | 8 Pl @ | s oO) 2 a] Si alala Ble jela| ole bola | 1 2) SG Bl = 2 Qo Ay o| x] 2] 3 + al|—|o o/@2@]/Higi= el ale|s| Slale Sel SlalClBl ae] 2|2| 8 als] 31 8/8] Z/=15) 2/2 Blsialsial/o;s qa! o|& 4173/3] q|4) 4) 2 Sim ]/Piag a a |'o/PISM] Ol gl] o/s Li) ala O;ei Hil ale Bi; S/S) el ole o| o| o| es Bb) al) alate S| 2 ° S/°o|8 Hl =| Ble] o Blal@/SlAlelslz/Ss|s[ojaisje/a| r 7 F Ee Ee — — Lg 1 Od 2 4 alr ! Om ~~ 1 THE REPTILIA OF THE ARUNDEL FORMATION BY RICHARD SWANN LULL The fossil reptiles of the Potomac, while not so abundant in numbers or kinds as in the Morrison of our Western States, nevertheless compare very closely with the latter, as nearly all of the Potomac genera and, in some instances, very closely allied if not identical species are found in the West. A striking similarity also prevails between the Potomac on the one hand and the Wealden of Europe on the other, while one important Maryland genus is reported from a lower horizon than the Wealden and none from a higher level. The Potomac fauna is largely dinosaurian, all of the sub-orders being represented, in addition to which there is a crocodile, together with at least one turtle and a ganoid fish. The Dinosaurs The carnivorous dinosaurs are represented by at least three species. One, the common Allosaurus, the European representative of which is Megalosaurus, may be recognized by feet and limb bones, vertebre, and teeth. This species, which has been named Allosaurus medius by Pro- fessor O. C. Marsh, was a creature of large size, comparing very favorably with Allosaurus fragilis of the West, the estimated length of which is 34 feet. It walked entirely on the hind feet after the manner of its kind, using the hands for grasping, and never for locomotion. The teeth are sharp pointed, like recurved daggers, with finely serrated edges, and often show a considerable degree of blunting’ through wear. 174 THE RepPritra oF THE ARUNDEL FoRMATION Another, much larger form, seems to have been present, though leaving the most meagre record of its existence in the shape of a single verte- bra—evidently that of a Creosaurus, to which the name of potens, the powerful, is given. This animal must have resembled Allosaurus very closely. Beside the huge carnivores, there were lesser ones of the most delicate build, with bones lightened by the development of interior spaces, doubt- less filled with air, as in the birds, until an almost paper-like thinness of the bone resulted. The Maryland animal, known only from the teeth and a single claw, resembled in tooth and claw its western allies. The latter Professor Marsh called Celurus, hollow tail, in allusion to the pneumatic bones, and to the Arundel species he gave the name of Celurus gracilis. This animal must have been extremely active, preying upon feebler reptiles and possibly upon the primitive mammals and birds of that day. Of the plant-feeding dinosaurs, the sub-order of great quadrupeds, the Sauropoda are represented by at least one genus Pleurocelus, possibly by others; but this is not certain. Pleurocelus is a long-legged type, apparently of small size, though most of the individuals represented were immature at the time of their death, though, strangely enough, of fairly constant size, which seems to imply either a wholesale slaughter of the young or that they really had reached the average stature, though not full maturity. Of these, two species are represented, one Pleurocelus nanus, the restoration of which is shown on pl. xi, was but 12 feet or so in length by 4 feet in height; a pigmy compared with the colossal bulk of Brontosaurus of the West with its length of over 60 feet. Pleurocelus nanus is by far the best known of the Potomac dinosaurs for more than half of all the material collected may be attributed to it. It was lightly built, though, in common with its allies, this lightness was largely confined to the skull and backbone, while the limb bones were much more solid in texture. Pleurocelus resembles most closely the form known as Morosaurus, a genus of wide distribution, from which it differed mainly in the greater relative length of the fore limbs and of MARYLAND GEOLOGICAL SURVEY 175 the centra of the vertebra. The teeth, which are slender, slightly flat- tened cylinders, sometimes nearly straight, again spoon-shaped, with blunt cutting edges, imply a very soft vegetable food, probably in the form of an aquatic plant, which grew in sufficient profusion to enable these creatures to satisfy their needs. ‘Phe Sauropoda were apparently of wading habits though, with such small types as this, land locomotion was doubtless not only possible but probable. Pleurocelus nanus has allies.so near akin as to be nearly indistinguishable, both in the Morrison beds of the West and the Upper Jurassic (? Kimmeridgian) near Havre, France, while somewhat more remotely related types are reported from the Kimmeridgian of Sussex and of the Isle of Wight. Another species of Pleurocelus, to which Professor Marsh gave the name of altus in allusion to its greater size, is also found in Maryland, though its known remains are very few compared with those of its ally. In size it exceeded that of Pleurocelus nanus by about two and a half times, giving it an estimated length of at least 30 feet. Its limb bones were much slenderer than those of a Morosaurus of equivalent length, indicating an animal of greater activity. Another genus, Astrodon, described years ago by Dr. Leidy from one or two teeth, is a near ally, if not identical with Pleurocelus alius. Judgment is suspended, how- ever, until further light is forthcoming in the way of more material, for the teeth of Astrodon are extremely rare. To the orthopod or predentate dinosaurs may be referred two genera of Potomac forms, one a lightly built, agile, plant-feeding type, differing from Pleurocelus in many respects, of which two are perhaps the most striking. One is the character of the mouth armament, for, while in Pleurocelus the teeth were fragile structures situated along the jaws, but especially in the front of the mouth, in the form under considera- tion, Dryosaurus, the anterior portion of the mouth was toothless, and doubtless sheathed with horn like that of a turtle, while the teeth were contained in magazines in the cheek portion of the jaws, a relatively simple mechanism, however, when compared with the later Cretaceous types. The other distinctive feature is the bipedal gait, shown by the great difference in size of the fore and hind limbs. Doubtless, however, 12 176 Tue REPTILIA OF THE ARUNDEL FoRMATION Dryosaurus could rest upon all fours while feeding, using the bird-like hind limbs alone when in motion. Dryosaurus, a close ally of Laosaurus, the restoration of which is shown on pl. xiii, is found in the Morri- son beds of the West in the form of a nearly related species, Dryosaurus altus. To the Potomac form, because of~its greater size, among other distinctive features, the name of Dryosaurus grandis is given. The nearest European ally to the present species is Hypsilophodon foau from the English Wealden beds, smaller and in some respects more primitive than the American types and representing a collateral line of descent. The larger, more heavily built predentates of the Morrison and of Europe have not as yet been discovered in the Arundel deposits. This, however, is not surprising, for their habits of life differed so essentially from those of the Sauropoda that their remains are rarely found asso- ciated in the rocks Another locality for Potomac dinosaurs might readily disclose these larger terrestrial types. There is another predentate type, known from a number of similar teeth, to which the name of Priconodon crassus has been given by Marsh. These teeth indicate a relationship with the armored dinosaurs or Stegosauria, forms which, because of the increasing weight of their protective mail, came down on all fours, not only for resting but for actual locomotion, as the increasing power of the fore limbs gives evi- dence. Judging from the teeth alone the nearest ally of Priconodon is Paleoscincus costatus described by Leidy from the Judith River beds of Montana, which are of Upper Cretaceous age. The teeth of the known contemporary (Stegosaurus) are much smaller and of a more specialized character. Stegosaurus, however, is known to be a remarkably specialized side line, probably the terminal member of its race, as its remains are unknown above the Morrison formation. There were, however, more conservative armored types which persisted until the close of the age of reptiles, and to this race Priconodon seems to have belonged. One vertebral centrum has been found in the Arundel beds very similar to that of Stegosaurus, except that it is smaller, but, as it represents an immature animal, that distinction has but little weight. It has been MaryLanp GEOLOGICAL SURVEY " 177 provisionally referred to Priconodon crassus, but may possibly represent a genuine stegosaur, otherwise unknown. Other Reptiles The fauna includes a crocodile, Goniopholis, found in the Wealden and Purbeck beds of Europe and in the Morrison of Colorado and Wyoming. The teeth are so similar to those from the western quarries that the name Goniopholis affinis, the nearly related, is given to the Potomac type. These are crocodiles of moderate size, 6 feet or more in length, and may have resembled the modern genus Crocodilus, with its narrow snout, quite closely in general appearance. In addition to the crocodile there are occasional fragments of bone which give evidence of the presence of a turtle as yet unidentified. SUMMARY The Arundel fauna represents, so far as known, three orders: Dino- sauria, Crocodilia, and Testudinata. The presence of a ganoid fish is also indicated. The dinosaurs represent all of the sub-orders, including two of the heavier, megalosaurian carnivores, Allosawrus and Creosawrus, and one of the lighter, Compsognathoid type, Celurus. The quadrupedal Sauro- poda are represented by at least one genus, possibly two, Pleurocelus and Astrodon, including two or three species in all, while of the Ortho- poda there are two, one the unarmored Dryosaurus, the other, Pricono- don, evidently belonging to the armored group or Stegosauria. The dinosaurs show none of the remarkable over-specialization, of the later Cretaceous types, but, on the contrary, represent the order at the crest of the evolutionary wave, before signs of decadence set in. Un- fortunately, owing to an almost utter dearth of terrestrial Jurassic de- posits, nothing is known of dinosaurian evolution in America from Newark time until we come to the horizon under consideration. In Europe the record, though still meagre, is more complete; but it repre- sents in every instance more primitive types than those of the Arundel and the Morrison. 178 * Tur REPTILIA OF THE ARUNDEL ForRMATION The character of these dinosaurs, and of the crocodile as well, cor- relates the beds wherein they are found absolutely with the Morrison (Como) of the West. An accurate comparison with European forma- tions is more difficult, as the faunas have fewer forms in common. Pleurocelus is reported from the Kimmeridgian as well as from the Wealden, but that from the former horizon may readily have been an- cestral to the Arundel type, although the European material is too frag- mentary to admit of a just comparison. Of the other dinosaurs, the affinities seem to be entirely with Wealden forms, Celurus being found therein, while Allosaurus compares in point of size and dentition with the Wealden Megalosaurus. Dryosaurus has its nearest European ally in Hypsilophodon, again a Wealden type, and the crocodile, Goniopholis, is reported from the Wealden and its marine equivalent the Purbeckian, not from the older Jurassic levels. The weight of this evidence would seem to place this fauna beyond the Jurassic into the beginning of Cretaceous times. SYSTEMATIC PALEONTOLOGY OF THE LOWER CRETACEOUS DEPOSITS OF MARYLAND BY RICHARD SWANN LULL, WILLIAM BULLOCK CLARK, AND EDWARD WILBER BERRY SYSTEMATIC PALEONTOLOGY LOWER CRETACEOUS VERTEBRATA ss sseieaecraceniese seater RicHarp Swann Lott. MOUMDUS CAS cisco eteme dine smcenem ite waters WILLIAM BULLOCK CLARK. PTERIDOPHYTA, 2 g:s0 cages greene cemee esa Epwarp WILBER Berry. OY CADOPHY LAD saccwigsspectiondsiewewens EpwarpD WILBER BERRY. GYMNOSPERMZ ....... oon Epwarp WILBER BERRY. MONOCOTYLEDONA ..............048. Epwarp WILBER BEgry. DICODPYLEDON AD aavcaas wes ocnresaioeeaaene EpwarpD WILBER BERRY. VERTEBRATA Cass REPTILIA Order DINOSAU RIA Suborder THEROPODA Family MEGALOSAURIDAE Genus ALLOSAURUS Marsh ALLOSAURUS MEDIUS Marsh Plate XIV, Figs. 1-3 Allosaurus medius Marsh, 1888, Amer. Jour. Sci., ser. iii; vol. xxxv, p. 93. Allosaurus Bibbins, 1895, Johns Hopkins Univ. Circulars, vol. xv, fig. G. Antrodemus medius Hay, 1902, Bull. U. S. Geol. Survey, No. 179, p. 489. Allosaurus medius Hay, 1908, Proc. U. S. Natl. Museum, vol. xxxv, p. 353. Description —tThe type (No. 4972, U. 8S. National Museum) consists of a single tooth, the other material mentioned by Marsh in his original description being removed to the genus Dryosaurus (vide infra, p. 204). Marsh’s description of the type is as follows: “The teeth are remark- ably flat and trenchant, with the edges finely serrated, and the surface very smooth. ... One tooth has the crown 30 mm. in height; its antero- posterior diameter at base 15 mm.; and its transverse diameter 7 mm.” There are several larger, better preserved teeth among the material, one of which (No. 5685, Goucher College) shows decided wear. The most perfect is one in the possession of the Hon. Charles E. Coffin,” Muirkirk, Maryland (pl. xiv, figs. 1,2). Itis about 3 inches (76 mm.) in length and 14 inches (28.7 mm.) in the antero-posterior diameter. The crenulations of the margin cease about midway toward the root on the anterior convex border, but extend the length of the crown on the posterior edge. There is a slight variation in the size of the crenulations, as they are somewhat coarser in the larger teeth. Or No. 3121, Goucher College. 184 SystTEMATIC PALEONTOLOGY The two vertebrae which are here referred to this species indicate an animal of the same approximate size as the teeth and phalanges. One (No. 2534, G. C.), which seems to be a posterior presacral, has a form quite similar to the type of Allosaurus fragilis, but relatively somewhat less constricted in the middle. It agrees in having the same somewhat flattened inferior surface. Anteriorly, the centrum has a shallow concavity, while posteriorly it is nearly plane. The pedicels of the neural arch are stout and the neural canal seems to be broader than in the type of A. fragilis, possibly owing to the fact that the vertebra is a more posterior one. The two agree in the depression on either side, which, however, is somewhat less marked in the present species. DIMENSIONS WSN StH said days aries Sieh s.ce aeneus a alow ea wees 90.0 mm. Least diameter of centrum............. ccc cece eee 68.5 mm. Diameter of anterior face as preserved............ 105.0 mm. Diameter of posterior face as preserved.......... 95.5 mm. Mere ht. Of Centrum y iic.v.ccleeies sae wreaiiarens Sauii-e cients 85.0 mm. The anterior caudal vertebra (No. 2614 a, G. C.) is that of a young individual, as the neural arch had not codssified with the centrum. Internally it seems to have been composed of rather coarse, cancellous tissue with no trace of an internal cavity, as in the type of Antrodemus, as figured by Leidy.* The anterior face is slightly concave, the posterior one nearly plane; and while the centrum is constricted decidedly in the middle there is no trace of the lateral depressions seen in the presacrals. DIMENSIONS GONBtD siciicnws sea ewan ans Mae 4 tayo eee ee aterecaspneris 107 mm. Least, QiaiMieten® Dunker, Mon. Norddeutsch. Wealdenbildung, 1846, p. 12, pl. v, fig. 3. 220 SYSTEMATIC PALEONTOLOGY ‘Genus ACROSTICHOPTERIS Fontaine [Mon. U. 8S. Geol. Survey, vol. xv, 1890, p. 106] This genus is characterized as follows by its describer: “ Fronds prob- ably creeping, with very long, often flexuous rachises, which seem to to have been more or less succulent; pinne going off obliquely, long and apparently slender; ultimate pinne or pinnules subopposite to alternate, comparatively short, and cut down nearly to the rachis into more or less cuneate-flabellate pinnules or primary segments. These are divided gen- erally into cuneate-flabellate segments, which in turn are separated into oblong segments, ending in oblong, or ovate-obtuse, or acute teeth; pin- nules decurrent and forming a wing; nerves slender but distinct, flabel- lately diverging, forking dichotomously, and ending in the teeth; fructi- fication occurring on the basal segments of the pinnules, in the upper portions of the frond on the upper one alone, in the lower portions on the upper and lower ones, the fructified segments close appressed to the prin- cipal rachis. The fructified segments are so modified as to take the form of leathery, rounded, or elliptical segments, which on the lower side are covered by the naked sori, and seen from the upper side, espe- cially when compressed on the clay, look. like pods.” The fructification characters should be modified to include those of Acrostichopteris pluri- partita, which appear to represent entire pinnules reduced to fertile seg- ments and not merely basal lobes of otherwise sterile pinnules thus transformed, as appears to be the case in Acrostichopteris longipennis. With all the collected material at hand it is difficult to see any con- clusive evidence that the species included in this genus were creeping in habit or had succulent rachises or that the the fertile segments were covered with naked sori. There is some evidence as to fructification char- acters, but this is most indefinite as regards details, and it may be noted that what are called nut-like seeds when applied to fragments referred by this author to his genus Baieropsis are described as above for frag- ments which he referred to the present genus, although neither the fertile nor the vegetative parts are distinguishable with certainty in these two supposed genera. MARYLAND GEOLOGICAL SURVEY 221 Most of the supposed species of Baieropsis are referred in the present work to Acrostichopteris, with which they are obviously allied in in- stances where they are not actually identical. They present no characters which are clearly those of the order Ginkgoales, except their subdivided fronds, which are suggestive of Baiera or Jeanpaulia, but might equally suggest various living Polypodiacee, e. g., Actinopteris and Rhipidopteris, or the family Schizeacee. Among fossil species they are very similar to forms referred to Sphenopteris, Palmatopteris, etc. Considerations which point away from Baiera in the direction of the ferns are the fine inequilateral outline of the leaves (pinnules), their decurrence, and their arrangement in a pinnate manner in a single plane. As has already been shown the species Baieropsis macrophylla Fontaine and part of Baieropsis expansa Fontaine have furnished fructifications which ally them with the family Schizeaces. With regard to the botanical position of Acrostichopteris little is known. According to Fontaine: “The genus in the naked sori is like Polypodium, but in most features stands nearest to Acrostichum, much resembling the section Rhipidopteris. In this latter, however, the fructi- fication is borne on separate pinnules. If we place the fructified pinnules of Rhipidopteris as basal segments on the sterile ones, we have a form strikingly like Acrostichopteris. This genus has also some resemblance to Marsilea.” Seward,’ on the strength of Fontaine’s conclusions, as quoted above, places the genus in the Polypodiacer. Potonié* places it as a synonym of his Palmatopteris in the artificial group of Sphenopterides. There is considerable collateral evidence for the reference of these forms to the family Schizeacee, or to what answered to this family in a general way in Mesozoic times. This evidence consists of a relationship of this sort shown by fertile specimens of Baieropsis expansa Fontaine and Baieropsis macrophylla Fontaine, which the writer has united’ to 1Seward, Wealden FI, pt. i, 1894, p. 60. 2 Potonié in Engler and Prantl, 1902, p. 490. ® Berry, Annals of Botany, vol. xxv, 1911, pp. 193-198. 222 SYSTEMATIC PALEONTOLOGY form the species Schizwopsis americana, and which differ but slightly in frond characters from the members of the present genus. Further- more, there is the close resemblance between the sterile fronds of this genus and those of Ruffordia, which, upon fairly satisfactory grounds, has been referred by Seward (loc. cit.) to the Schizeacex. Acrostichopteris may be compared with the modern Actinopteris, a monotypic genus of the Indoafrican steppes, with the neotropical genus Ehipidopteris, or with Schizea dichotoma Sw. and Schizea elegans Sw. of the family Schizeacee. It is not closely related to Acrostichophyllum Velenovsky (1889), of the Cenomanian of Bohemia. As here delimited it embraces six species in the Maryland-Virginia region. Of these, three species are confined to the basal beds or Patuxent formation, two species range through the whole Lower Cretaceous of this region, and are present as well in both the Lakota and Fuson formations of the Black Hills re- gion, and one species is confined to the Patapsco formation and is wide- spread in its occurrence. One additional species, suggestive of Acrosti- chopteris parvifolia of the Patuxent formation, and likewise close to the only remaining species, Acrostichopteris Rujffordi Seward* of the English Wealden, has recently been described by Knowlton* from the Kootanie of Montana. Considering for a moment the Portuguese homo- taxial deposits we find a considerable number of remarkably similar forms described by Saporta,’ all of which are referred to the form-genus Sphenopteris. Thus from the Upper Jurassic there is Sphenopteris. tenellisecta Sap., from the Urgonian S. cuneifida Sap., from the Aptian S. flabellisecta Sap., S. tenuifissa Sap., and S§. debilior Sap. These forms are certainly congeneric with Acrostichopteris, and with more representative material doubtless some species would be found to be common to both sides of the Atlantic. Some are more nearly like the forms segregated by Fontaine to form his genus Baieropsis, while others are of the type which this author referred to Acrostichopteris. 1 Seward, Wealden F'1., pt. i, 1894, p. 61, pl. vi, fig. 3. * Knowlton, Smith. Misc. Coll., vol. 1, 1907, p. 110, pl. xi, figs. 3, 3a. * Saporta, Fl. Foss. Portugal, 1894, pp. 25, 69, 127, 160, 161. MaryYLAND GEOLOGICAL SURVEY 223 ACROSTICHOPTERIS LONGIPENNIS Fontaine Plate XXIII, Figs. 1, 2; Plate XXIV, Fig. 7 Acrostichopteris longipennis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, p. 107, pl. clxx, fig. 10; pl. clxxi, figs. 1, 5, 7. Acrostichopteris densifolia Fontaine, 1890, Ibid. (pars), pl. clxx, fig. 11; pl. clxxi, figs. 2, 6; pl. clxxii, fig. 18 (non pl. xciv, fig. 4 which is referable to A. parvifolia Font.). Baieropsis foliosa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 209, pl. xciii, figs. 4-6. Baieropsis denticulata angustifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 210, pl. exii, fig. 7. Baieropsis denticulata angustifolia Fontaine, 1906, in Ward, Mon. U. Ss. Geol. Surv., vol. xlviii, 1905, p. 491. Acrostichopteris longipennis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 567. Acrostichopteris parvifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 558, pl. cxvi, fig. 5. Baieropsis foliosa Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 481, 482, 489, 504, 508, pl. cx, fig. 9. Acrostichopteris longipennis Berry, 1910, Proc. U. S. Natl. Mus., vol. XxXxviii, p. 627. Description—Fronds with relatively long pinne, decompound proxi- mad and becoming simpler distad, the ultimate pinnules subopposite to alternate, rather close set. Pinnules inequilateral and slightly decurrent, cut into several narrow sublinear divisions and terminated by two or more subacute teeth. The lower pinnules are wider and more laciniate, and more decidedly alternate on the stout rachis. Venation fine, but distinct, flabellate and dichotomous, ultimate divisions terminating in the apical teeth. The sterile and smaller specimens tend to much greater density than those of larger size or those showing traces of fructifications. The fructifications, which are illy defined in the coarse matrix, are borne on the proximal or distal or both basal segments of the pinnules; the segment or segments involved becomes wider and shorter and ellip- tical in outline. No details can be made out. This species is exceedingly common in the Patapsco formation, to which it is confined, being especially common in the beds of this age at Federal Hill. In Virginia it occurs at a large number of localities within this formation. 15 224 SysTeMATIC PALEONTOLOGY It is difficult to see what evidence, unless it be the supposed relation- ship with the modern Rhipidopteris, led Fontaine to claim a creeping habit for these forms. The rachis is sometimes more or less flexuous, but not markedly so, and the length is relatively great. Proximally, however, the rachis becomes stouter with decompound pinnez as broad or broader than they are long. It seems probable that this form was not a ground dweller with creeping rachis or rhizome, nor did it adhere to tree trunks, but reclined or clambered over the abundant erect Lower Cretaceous vegetation, as does the modern Lygodium. It appears to be closely related to Sphenopteris debilior Sap.’ of the Albian of Portugal. Occurrence.—Parapsco Formation. Near Wellhams, Federal Hill (Baltimore), Maryland. Near Brooke, 72d milepost, Hell Hole, Mouth of Hell Hole (?), White House Bluff, Dumfries Landing, Aquia Creek Cut, and Mt. Vernon, Virginia. Collections —U. S. National Museum, Johns Hopkins University, Goucher College. ACROSTICHOPTERIS ADIANTIFOLIA (Fontaine) Berry Plate XXIV, Figs. 2, 3 Baieropsis adiantifolia Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 211, pl. xcii, figs. 8, 9; pl. xciii, figs. 1-3; pl. xciv, figs. 2, 3. Baieropsis adiantifolia Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 684, pl. clxviii, fig. 8. Baieropsis adiantifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, pp. 510, 528, 538. Acrostichopteris adiantifolia Berry, 1910, Proc. U. S. Natl. Mus., vol. Xxxviii, p. 629. ' Description.—“ Stems moderately strong; leaves subopposite to oppo- site, closely placed, often imbricated, subquadrilateral to flabellate fan shaped, narrowed to a wedge-shaped base, and attached by a short pedicel which springs from the lower corner of the leaf, so that the inner margin of the leaves runs close to the main stem, parallel with it, and often overlapping it, while the lower margin of the leaves stands nearly at 1Saporta, Fl. Foss., Portugal, 1894, p. 161, pl. xxviii, figs. 5, 5a. MARYLAND GEOLOGICAL SURVEY 225 right angles with the main stem; leaves cut down to near the base into two principal laciniw, and those higher cut into two or more minor laciniz ; ultimate lacinise very shallow and strap shaped, ending in acute very short teeth, or rarely in narrowly elliptical and subacute ones; all the lacinie turned outwards or upwards, the lower margins of the leaves being entire or having sometimes an acute tooth; leaves in ascending towards the tips of the leafy branches have their lower margins directed more and more upwards, become smaller, assume more of an elliptical or a wedge shape, have the lacinie only on the upper margin, and, finally, coalesce to form a terminal leaflet, which at base shows three segments, but whose terminal portions are not seen; nerves fine but distinct, branching at base from a mother nerve, and then dividing repeatedly in a dichotomous manner so as to fill the lamine, and have the branches ending in the teeth. “The plant is most frequent at Fredericksburg, but is not abundant there, and is usually in a very fragmentary state. If we look to the shape of the leaves alone this curious plant is much like a fern of the type of Adiantum, but the gradations through different forms connect the specimens so closely with the flabellate leaves of Baieropsis that they cannot be separated by any good distinctions. The principal difference from the more common and typical forms of Bateropsis is found in the greater proportional width of the leaves and the smaller depth of the subdivision.” Fontaine, 1890. This species is based upon very fragmentary specimens, and it is very doubtful if the material identified from the Patapsco and Arundel forma- tions is the same as that from the Patuxent, the presence of this species from Chinkapin Hollow, Virginia, and Arlington and Fort Foote, Mary- land, being each based on a single, very poor specimen. Occurrence.—-PATUXENT ForMATION. Fredericksburg, Lorton (Tele- graph station), Potomac Run, Virginia. ArunprL Formation. Ar- lington, Maryland. Parapsco Formation. Fort Foote, Maryland (?); Chinkapin Hollow, Virginia (?). Collection.—U. 8. National Museum. 226 SYSTEMATIC PALEONTOLOGY ACROSTICHOPTERIS CYCLOPTEROIDES Fontaine Plate XXIV, Fig. 1 Acrostichopteris cyclopteroides Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 109, pl. xciv, fig. 8. Baieropsis denticulata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 210, pl. xciii, fig. 7. Acrostichopteris cyclopteroides Berry, 1910, Proc. U. 8. Natl. Mus., vol. Xxxvili, p. 630. ’ Description.—Pinnules rounded, fan shaped, cyclopteroid, divided into two or three principal segments, which are split wp into six or more sub- ‘ordinate linear oblong divisions terminated by subacute teeth. Rachis stout. Venation flabellate, the single vein which enters the base re- peatedly forking dichotomously, the ultimate divisions entering the teeth. This species is poorly characterized and is based upon infrequent and very fragmentary material from the single locality cited. It may well represent a slightly variable form of pinnule of one of the other more abundant Patuxent species, e. g., Acrostichopteris parvifolia Fontaine. In the foreign Cretaceous it is rather remotely suggestive of Sphenopteris flabellina Sap.’ from the Albian of Portugal. Occurrenee—PATUXENT ForMATION. Dutch Gap, Virginia. Collection—U. S. National Museum. ACROSTICHOPTERIS PARVIFOLIA Fontaine Plate XXIV, Figs. 4, 5 Acrostichopteris parvifolia Fontaine, 1890 (pars), Mon. U. S. Geol. Survey, vol. xv, 1889, p. 108, pl. xciv, figs. 5, 9, 10, 12; pl. clxxi, figs. 3, 4; pl. elxxii, fig. 4 (non Font., in Ward, 1906). Acrostichopteris densifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, pl. xciv, fig. 4 (non balance of citation). Baieropsis adiantifolia minor Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 212, pl. xciv, fig. 1. Acrostichopteris parcelobata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, ° 1889, p. 108, pl. xciv, figs. 6, 7, 11, 14. Acrostichopteris parvifolia Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 630. + Saporta, Fl. Foss., Portugal, 1894, p. 160, pl. xxviii, figs. 3, 6. MaryYLAND GEOLOGICAL SURVEY 227 Description——Pinnules small and generally remote, the distal ones short, all divided into three principal lobes which are variously dissected and terminated with two or more short, stout teeth. Venation as usual in this genus. This species is thus far confined to the Patuxent formation of Vir- ginia, the specimens from Maryland so identified by Fontaine proving to belong to Acrostichopteris longipennis, which is somewhat similar in appearance but usually much more dense in habit. The remains are rare and fragmentary at all of the recorded localities except Dutch Gap Canal, where they are not infrequent. They show no traces of fructifications. This species is very closely related to Acrosti- chopteris fimbriata Knowlton* of the Kootanie formation of Montana, and likewise to Acrostichopteris Ruffordi Seward* of the English Wealden. On the continent it is represented by the nearly allied and strictly congeneric species Sphenopteris tenellisecta Sap.” from the Upper Jurassic, and Sphenopteris flabellisecta Sap." from the Aptian of Portugal. Occurrence—PaTuxENT Formation. Dutch Gap, Fredericksburg, Trents Reach, Potomac Run, Virginia (not Federal Hill; Md.). Collection.—U. 8. National Museum. ACROSTICHOPTERIS PLURIPARTITA (Fontaine) Berry Plate XXIV, Fig. 6 Baieropsis pluripartita Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 208, pl. Ixxxix, fig. 4; pl. xc, figs. 2-5; pl. xci, figs. 1, 3, 4, 7; pl. xcii, figs. 1, 2, 6. Baieropsis pluripartita minor Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 208, pl. xci, fig. 5; pl. xcii, fig. 3, 4. Baieropsis longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 210, pl. xci, fig. 6. : Baieropsis pluripartita ? Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 685, pl. clxviii, figs. 9-12. 1Knowlton, Smith. Misc. Coll., vol. 1, 1907, p. 110, pl. xi, figs. 3, 3a. 2 Seward, Wealden FL, pt. i, 1894, p. 61, pl. vi, fig. 3. ® Saporta, Fl. Foss. Portugal, 1904, p. 25, pl. xiii, fig. 1. * Saporta, Ibid., p. 69, pl. xv, figs. 14, 15. 228 SysTEMATIC PALEONTOLOGY Baieropsis pluripartita Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, pp. 479, 481, 482, 505, pl. evii, fig. 1. Baieropsis longifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xviii, 1905, pp. 505, 517, pl. cxi, fig. 3. Acrostichopteris pluripartita Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 631. Description—Pinnules large in size, inequilateral, fan shaped, sub- opposite, at an acute angle of divergence, narrowly divided almost to the base into three principal and a varying number of narrow linear sub- ordinate segments. Venation of the usual character in this genus, slen- der but distinct. The apices are usually, if not always broken off so that their character cannot be made out. Rachis comparatively slender. This species includes certain indefinite fertile specimens upon which Fontaine based the characters of the supposed fruits in his genus Baterop- sis. This fructification is clearly to be correlated with Acrostichopteris pluripartita, since one specimen shows a characteristic pinnule of this species. The preservation is poor and the most that can be made out are oval bodies apparently representing reduced or transformed seg- ments of pinnules, all the segments of which are fertile in this case, and not merely the basal ones as is shown in so many specimens of Acrostichopteris longipennis. Fertile specimens of the present species are, on the other hand, very rare and fragmentary. This species is present in both the. Patuxent and Patapsco formations of Maryland and Virginia. It is also recorded somewhat doubtfully from both the Lakota and Fuson formations in the Black Hills rim of Wyoming. In Portugal Saporta describes several very similar forms. These include Sphenopteris cuneifida of the Urgonian-Aptian, Sphen- opteris dissectiformis* of the Aptian (?), Sphenopteris tenuifissa* of the Albian, and Sphenopteris flabellina, also of the Albian. From the Neocomian sandstone near Quedlinburg in Saxony, Richter * +Saporta, Fl. Foss. Portugal, 1894, pp. 69, 127, pl. xvi, fig. 11, pl. xxiii, fig. 5. 2 Tbid., p. 68, pl. xv, fig. 18; pl. xvi, figs. 12, 18. 3 Tbid., p. 161, pl. xxviii, fig. 4. 4Tbid., p. 160, pl. xxix, fig. 16. 5 Richter, Zeits. deutsch. geol. Gesell., Band li, 1899, Verhandlungen, p. 40. MaryLANp GEOLOGICAL SURVEY 229 has mentioned fossils which he states are very close to Baicropsis pluri- partita Fontaine. Occurrence.—PaTUXENT ForMATION. Fredericksburg, Telegraph Sta- tion (Lorton), Trents Reach, Dutch Gap, Virginia; New Reservoir, District of Columbia. Patapsco Formation. Hell Hole, 72d milepost, near Brooke, Virginia; Overlook Inn, Maryland. Collection—U. 8S. National Museum. ACROSTICHOPTERIS EXPANSA (Fontaine) Baieropsis expansa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 207, pl. lxxxix, fig. 3; pl. xe, fig. 1; pl. xci, fig. 2; pl. xcii, fig. 5 (non pl. lxxxix, fig. 1 which is made the type of the genus Schizwopsis). Description.—“ Leaves very large, having probably the width of 12 cm. and the length of over 15 cm., attached by slender pedicels, and appar- ently distributed as given in the generic description, i. e., pinnately on leafy twigs, which themselves are arranged pinnately on a principal stem, the main stem and branches-ending in leaves of the normal kind; leaves divided to near their bases into several principal lacinis, which in turn are subdivided at varying heights into subordinate lamine, and these into ultimate ones that are long and narrow, ribbon-like, with the ends not seen; all subdivide dichotomously and diverge so as to give the leaf a fan shape; the ultimate laciniw, 1.5mm. wide and under; the nerves distinct, although slender. They fork at the base in the primary lacinie, and then repeatedly subdivide dichotomously in the lacinize at varying intervals, the branches being more or less parallel.”—Fontaine, 1890. In its vegetative characters the present species is not very different from Schizeopsis americana Berry, being, however, somewhat smaller, with as yet unknown fructification characters and the veins with double vascular strands. Occurrence.—PatuxENtT Formation. Fredericksburg, Dutch Gap, Trents Reach, Virginia. Collection —U. 8. National Museum. 230 SYSTEMATIC PALEONTOLOGY Genus RUFFORDIA Seward [Wealden FI., pt. i, 1894, p. 75] This genus was proposed by Seward for certain ferns previously re- ferred to the frond genus Sphenopteris, the fertile pinne of which, found in the English Wealden, suggest a relationship with the modern species of Aneimia, a relationship fully borne out by the appearance of the sterile pinne. Fronds tri-quadripinnate, triangular in outline, rachis frequently flexuous. Pinne alternate, broadly triangular to ovate-lanceolate. Pin- nules delicate, decurrent, somewhat variable, with linear acuminate ovate cuneate ultimate divisions, dentate, or denticulate. Veins flabel- late, repeatedly forked. Fertile pinne considerably reduced with scat- tered sporangia. A number of extremely rare and fragmentary Potomac ferns have been described by Professor Fontaine as various species of Sphenopteris. Five of these are here united to form the two following species of Ruffordia. It is true that no fertile pinne have been found in asso- ciation with the sterile pinne in this country, as is the case in the English Wealden, but as nearly as can be made out from such imperfect material as we possess the form and habit of the sterile pinne is so close that the identity of the remains from both sides of the Atlantic is reasonably certain. Attention should be called to the resemblance between the pinne in Ruffordia and in Acrostichopteris, interesting in connection with the fact that there are some grounds for supposing that the latter genus is related to the Schizeacex. ‘ In any event the American material does not show the specific differ- entiation assigned by Professor Fontaine, nor is it desirable to perpetuate the use of the generic term Sphenopteris for forms younger than the Paleozoic. RUFFORDIA ACRODENTATA (Fontaine) Berry Plate XXIII, Figs. 5, 6 Sphenopteris acrodentata Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 90, pl. xxxiv, fig. 4. Ruffordia Gepperti var. latifolia Seward, 1894, Wealden FL, pt. i, p. 85, pl. vi, figs. 1, la. MARYLAND GEOLOGICAL SURVEY 231 Description Apparently tripinnatifid, more open and with the ulti- mate segments shorter and broader than in the following species. Lower pinnules divided almost to the rachis becoming reduced through lobed to simple pinnules distad; summits obtusely rounded, minutely toothed. Venation flabellate. Veins repeatedly forked, the ultimate branches end- ing in the marginal teeth. This species is very close to the following, of which it is made a va- tiety by Professor Seward, who states that the English material shows many intermediate forms, although the extremes are different enough. As the scanty American material lacks intermediate forms it has seemed best to treat it as belonging to a distinct species at the same time recog- nizing its resemblance to the following and the possibility that more representative material might demonstrate their identity. Occurrence.—PaTUXENT Formation. Dutch Gap, Virginia. Patapsco Formation. Federal Hill (Baltimore), Maryland. Collection.—U. S. National Museum. Rurrorpia Ga@rrrrtr (Dunker) Seward Plate XXIII, Figs. 3, 4 Cheilanthites Gepperti Dunker, 1844, Norddeutsch, Walderthon, Programm der héheren Gewerbschule in Cassel, 1843-1844, p. 6. Sphenopteris Gepperti Dunker, 1846, Mongr. d. Norddeutsch. Wealdenbild- ung, p. 4, pl. i, fig. 6; pl. ix, figs. 1-3. Sphenopteris Gepperti Bronn, 1848, Index pal., vol. 2, p. 1168. Sphenopteris Gepperti Brongniart, 1849, Tableau, p. 107. Sphenopteris Gepperti Unger, 1850, Gen. et Sp., p. 109. Sphenopteris Hartlebeni Dunker, op. cit., p. 4, pl. ix, fig. 9. Sphenopteris Hartlebeni Bronn, loc. cit. Sphenopteris longifolia Dunker (non Phillips nec. Feistm.) op. cit., p. 4, pl. viii, fig. 6. ‘ Sphenopteris adiantifrons Ettingshausen, 1851, Jahrb. d. k. k. Geol. Reichs- anst., Jabrg. II, p. 157. Sphenopteris Jugleri Ettingshausen, 1852, Beitr. z. Fl. d. Wealdenperiode, p. 15, pl. iv, fig. 5. Sphenopteris Hartlebeni Schimper, 1869, Pal. Végét., tome i, p. 394, pl. xxx, figs. 2, 3. Sphenopteris longifolia Schimper, Ibid. Sphenopteris Jugleri Schimper, Ibid. Sphenopteris Auerbachi Trautschold, 1870, Der Klin’sche Sandstein, Nouv. Mém. Moscou, vol. xiii, p. 207 [19], pl. xviii, fig. 5. 232 SYSTEMATIC PALEONTOLOGY Sphenopteris Gepperti Schenk, 1871 (pars) Paleont., vol. xix, p. 7 (209), pl. iv, figs. 4, 5; pl. ix, fig. 2 (non pl. iv, figs. 2, 3). Sphenopteris Gepperti Dupont, 1878, Bull. Ac. R. Belg., ser. ii, vol. xlvi, p. 396. Sphenopteris valdensis Heer, 1881 [pars], Fl. Foss. du Portugal, p. 14, pl. xv, fig. 11. (?) Sphenopteris sp. Yokoyama, 1889, Jour. Coll. Sci., Imp. Univ. Japan, vol. iii, pt. i, p. 34, pl. xiv, figs. 13, 13a. Sphenopteris cf. Gepperti Nathorst, 1890, Denks. k. Akad. Wiss., Wein, Band Ivii, p. 51, pl. vi, figs. 2, 3. Cladophicbis sphenopteroides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 79, pl. xxi, fig. 4. Thyrsopteris heteromorpha Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 186, pl. lii, fig. 1. eve Sphenopteris thyrsopteroides Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 89, pl. xxv, fig. 3; pl. lviii, fig. 5. Sphenopteris spatulata Fontaine, Ibid., p. 93, pl. 1, fig. 4. Sphenopteris pachyphylia Fontaine, Ibid., fig. 5. Sphenopteris valdensis Fontaine, 1893, Proc. U. S. Nat. Mus., vol. xvi, p. 263, pl. xxxvi, fig. 2. Sphenopteris valdensis Saporta, 1894, Fl. Foss. Portugal, p. 126, pl. xxiii, fig. 9; pl. xxiv, figs. 2, 3. Ruffordia Gepperti Seward, 1894, Wealden Flora, pt. i, pp. 76, 77, pl. iv, pl. v; pl. x, figs. 1, 2. Sphenopteris tenuicula Yokoyama, 1895, Journ. Coll. Sci., Imp. Univ., vol. vii, p. 217, pl. xx, fig. 11; pl. xxi, figs. 2, 3; pl. xxviii, fig. 6. Ruffordia Gepperti Seward, 1900, Fl. Wealdienne de Bernissart, Mém. Musée d’Hist. nat. Belgique, Année 1900, p. 18, pl. iii, fig. 33. (?) Cladophlebis sphenopteroides Penhallow, 1905, Summary, Geol. Surv., Canada, 1904, p. 9. Cladophlebis sphenopteroides Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 519. Description——“ Sphenopteris fronde tripinnata, apicem cersus bipin- nata, pinnis alternis distantibus vel plus minus approximatis, pinnulis alternis clavatis petiolatis apice laciniatis vel subemarginatis, laciniis obovatis, cuneatis, nervis obsoletis, rhacibus tenerrimis canaliculatis.”— Dunker, 1846. Abundant material from the English Wealden has enabled Professor Seward (loc. cit.) to considerably amplify our knowledge of this plant by his description of the fertile pinne, which are considerably reduced and bear scattered sporangia, the structure of which could not be made out. MaryLanp GroLogicaL Survey 233 The American material which is very limited and poor consists of frag- ments of pinne all from localities in Virginia, and very badly figured by Professor Fontaine, who shows an enormously winged rachis in the speci- men he calls Sphenopteris thyrsopteroides. Specifically identical frag- ments are made the basis for two additional species of Sphenopteris, i. e., 8S. pachyphylla and S. spatulata. This species is wide ranging and long lived, having been recorded from strata of Neocomian, Wealden, Barremian, or Albian age in England, Germany, Belgium, Russia, Portugal, Austria, and Japan. Although not recorded from the Arctic regions there are a number of forms de- scribed by Heer from the Kome beds as species of Sphenopteris, Jean- paulia, and Asplenium that are at least very close to this species. Extremely fragmentary remains from the Trinity division at Glen- rose, Texas, which are identified with Sphenopteris valdensis Heer by Professor Fontaine are probably referable to this species. Occurrence—PatTUxENT Formation. Fredericksburg, Dutch Gap, and Trents Reach, Virginia y Ivy City (?), District of Columbia. Collection —U. 8. National Museum. Family MATONIACEAE (?) Genus KNOWLTONELLA gen. nov. Fronds of medium or large size, pseudo-dichotomous in habit, at least in part. Rachis stout. Pinnules linear-lanceolate, acuminate, attached by their entire base (occasional specimens slightly constricted), obliquely placed and usually more or less decurrent. This obliquity increases proximad until finally the rachis may be bordered by long and narrow gradually decreasing wings, which in some specimens appear to be con- tinued downward beyond a fork. Occasionally pinnules higher up will (abnormally) show this alate character. Distad the pinnules become reduced in size and more or less confluent, forming a lamina with ser- rate marginal teeth of greater or less incision. Texture very coriaceous. Venation immersed. The midvein is prominent below and continues to 234 Systematic PALEONTOLOGY the apex of the pinnule, although much diminished in calibre. The later- als branch at a wide angle and fork somewhat like those of Laccopteris; anastomosis has not been observed, however. The presence of dormant buds at the ends of the primary axes has not been observed. Fructifi- cation characters unknown. This genus, of which the following species is the only one known, is clearly a member of the important Mesozoic fern alliance usually segre- Le oon Fic. 3.—Sketch map of the world showing the Mesozoic and existing dis- tribution of the family Matoniacese. Circles Upper Triassic, multiplication sign = Jurassic, plus sign == Lower Cretaceous, stars—= Upper Cretaceous, en- closed dots show present occurrences. gated to form the families Gleicheniacese and Matoniaceex, although the exact line of cleavage between the two, granting that there is such a line, has not been determined with precision for the existing, much less the fossil forms. The pseudo-dichotomy, which is such a characteristic 1Christ groups these two families in a separate class which he calls Oligangia. Die Farnkrauter der Erde, Jena, 1897, p. 335. MARYLAND GEOLOGICAL SURVEY 235 feature of most of these ferns is rare in the other fern-families, and when present is usually a variable and not a characteristic habit.’ The genus, which is obviously unlike any previously known, is named in honor of Dr. F. H. Knowlton, as a slight appreciation of the value of his contributions to our knowledge of fossil plants. As Knowltonia has already been used by Salisbury for a member of the Ranunculacex, the present genus may be known as Knowltonella. The Matoniacee, of which but two existing species are known, from a very restricted area in the East Indies, are of considerable importance in the Mesozoic and enjoyed a wide range. The occurrence of the existing species is shown on the accompanying sketch map, as well as the known occurrences of fossil representatives. These have been obtained by plotting the recorded oc- currences of Laccopteris Presl, Matomdiwm Schenk, Phlebopteris Bron- gniart, Microdictyon Saporta, Gutbiera Presl, Carolopteris Debey and Ettinghausen, and Marzaria Zigno, and may in some instances represent incorrect identifications. It will be seen that this family, while ap- parently present in the Arctic region and in North America, was a prom- inent element in European Mesozoic floras from the Upper Triassic through the Jurassic and Lower Cretaceous, and continued to be repre- sented well into the Upper Cretaceous. Some of the Huropean material is very satisfactory, and has been the basis for a considerable body of literature. KNOWLTONELLA MaxonlI sp. nov. Plates XXV, XXVI, XXVII Description—Fronds as described for the genus (supra). Pinnules of normal form varying in size from 0.6 cm. in length by 1.5mm. to 1¥For a discussion of the living Gleicheniaceez see Underwood, A prelimin- ary review of the North American Gleicheniacee, Bull. Torrey Bot. Club, vol. xxxiv, 1907, pp. 243-262. : For a comparison of the living and fossil Mationiacee see Seward, On the structure and affinities of Matonia pectinata R. Br., with notes on the geo- logical history of the Matoninez, Phil. Trans. Roy. Soc., Lond., vol. exci, 1899, pp. 171-209, pls. xvii-xx. 236 SYSTEMATIC PALEONTOLOGY 6mm. in width, averaging 1.3cm. in length by 2.5mm. in width. Distad the pinnules are united for more than half their length, proximad they are more or less decurrent. There are great irregularities in the latter feature. One secondary limb may be alate for almost half its length, while the other may be pectinate entirely to the base. If it be granted that these forms are comparable with the modern species of Gleichenia or Dicranopteris, then they show similar irregularities in the suppression and development of the primary axes. Soral characters unknown. This species is exceedingly abundant at certain localities within the Patapsco formation of the Potomac valley, to which it is thus far con- fined. Specimens of any size are perfectly characteristic, but small fragments may be readily mistaken for Cladophlebis, Laccopteris, and other genera. The varying appearance assumed by this species is well shown on the accompanying plates. From the abundance of the remains at certain outcrops this species must have been gregarious after the manner of the modern Matonia pectinata, Dicranopteris fulva, or the various other species of the latter genus, as well as those of the allied genus Gileichenia. The alate rachises suggest somewhat the modern Matonia sarmentosa Baker. (Phanerosorus Copeland, Philip. Journ. Sci., vol. iii, 1908, p. 344.) The writer has seen a specimen of the common Dicranopteris fulva (Desv.) Underwood, collected by Mr. W. R. Maxon in Jamaica, which departs widely from the usual form in the direction of Matonia sarmentosa Baker, and also in the direction of Gleichenia (sens stricto, i. e., with short, rounded segments), which also serves to accentuate the relationship between these various forms, since it is con- ceivable that the alate rachises of Knowltonella Mazoni are near the orig- inal type (or are morphologically short pinnules which have become fused), and the normal pinnules are acquired just as the form of Dicranopteris fulva may be considered as of phlogenetic significance and the normal form the acquired form. Similarly the form of Matonia sarmentosa, while due to the specialized habitat of the species, and in that sense acquired, harks back to the ancestral forms whose pinnule characters antedated those of Matonia pectinata. MARYLAND GEOLOGICAL SURVEY 237 Knowltonella Maxoni is remotely suggestive of the three species of Phiebomerts described by Saporta from the Albian of Portugal. It is named in honor of Mr. Wm. R. Maxon, of the National Herbarium, in appreciation of his helpful interest in fossil fern-remains. Occurrence.-—Patapsco Formation. Stump Neck, near Glymont, Maryland; near Widewater, Virginia. Collections—Johns Hopkins University, Maryland Academy of Science. Family CYATHEACEAE Genus DICKSONIOPSIS gen. nov. The genus Dicksoniopsis is proposed as a convenient form-genus for fern fronds which show an undoubted relationship with the modern ferns of the tribe Dicksoniex, but which it is impossible to correlate positively with any of the existing genera of this subfamily. The term Dicksonites would be preferable but it is preoccupied, having been used by Sterzel to designate certain Carboniferous and Permian fern-like remains which are not even remotely related to the form under discussion. Probably most ‘of the older Mesozoic species of Dicksonia, of which there are a considerable number, should be referred to the present genus, however, only the single Potomac species is discussed in the present connection. DICKSONIOPSIS VERNONENSIS (Ward) Plate XXVIII, Figs. 3, 4 Scleropteris vernonensis Ward, 1895, 15th Ann. Rept. U. S. Geol. Surv., p. 349; pl. ii, figs. 1-3. Dryopteris virginica Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 491 (non Fontaine, 1890). Scleropteris vernonensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 501, pl. evii, fig. 10. Dryopteris parvifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 541, pl. cxiv, fig. 7 (non other citations of this species). Description.—Frond finely divided, bipinnate or bipinnatifid. Pinne alternate, lanceolate in outline, passing distad into inequilaterally lobed pinnules. ~ Pinnules alternate, ascending; the basal pair usually about 238 SYSTEMATIC PALEONTOLOGY 50 per cent larger than their fellows and more lobate. The usual type of pinnule is united to the rather slender rachis by a somewhat con- stricted base. The proximal margin is usually entire, the apex rounded and the distal margin has usually a single rounded lobe, separated from the rounded apical lobe by a shallow sinus. The venation is fine and sparse, and consists essentially of a single forked vein, one limb of which runs to the apex of the pinnule and the other runs to the distal lobe. The fertile pinne are slightly reduced in size and more open than the sterile, and bear an elliptical sorus at the apex of the vein which runs to the distal lobe of the pinnule. No details of structure can be made ‘out. This species was described by Ward in 1895 as a species of Scleropteris and compared with Scleropteris tenuisecta Saporta from the French Kimmeridge. It resembles this species somewhat in general appearance, and this is especially marked in the case of some of the more open speci- mens with trilobate pinnules figured by Ward from Mt. Vernon. The fertile specimens show conclusively, however, that this species is closely allied to the modern forms of the tribe Dicksoniew of the family Cy- atheaceze. Professor Fontaine has described Dicksonia pachyphylla from the Shasta of California and Dicksonia montanensis from the Kootanie of Montana, both of which have the lamina almost entirely reduced in the fertile pinne. The most nearly related fossil species is Dicksonia bellidula Heer * from the Kome beds of Western Greenland. Curiously enough this was originally described by Professor Heer as a species of Scleropteris,’ just as Professor Ward made the same mistake in his identification of the Potomac species. The Arctic species has shorter, broader, and more rounded pinnules or pinnatifid lobes of the pinnae. It resembles the Potomac species in having a single elliptical sorus at the apex of a vein on the distal margin of each pinnule or pinnatifid lobe of a pinna. 1 Heer, Fl. Foss. Arct., Band vi, Abth. ii, 1882, p. 1. ? Heer, Fl. Foss. Arct., Band iii, Abth. ii, 1874, p. 35, pl. ii, figs. 17c, d, 18; pl. xi, fig. 8. Maryann GEoLogicaL SURVEY 239 Occurrence.—ARUNDEL Formation. Arlington, Maryland. Parapsco Formation. Mt. Vernon, White House Bluff, Virginia. Collection. U. 8. National Museum. Family POLYPODIACEAE Genus. CLADOPHLEBIS Brongniart [Tableau, 1849, p. 25] This genus is essentially a form-genus which is restricted at the present time to include only certain fern remains of Mesozoic age, although this type of frond is practically identical with those of some Paleozoic genera, as, for example, Pecopteris, and it can also be closely matched by a va- riety of Tertiary and living ferns. Cladophlebis was proposed by Brongniart in 1849 for those species which formed the section Pecopteris neuropteroides in his “ Histoire des végétaux fossiles,” which he regarded as transitional between Pecopteris and Neuropteris. Certain of their characters were mentioned but no formal diagnosis was attempted. Saporta, who was perhaps the first to define the genus with precision gives the following characterization : “Frons pinnatim divisa, pinnule ab alterutra discrete vel vix inter se coherentes rachi tota basi adnate aut plus minusve contracte subque auriculate integre rariusve dentate; nervuli e nervo medio orti apicem versus attenuati vel evanidi primum obliqui, dein curvati furcatoque divisi.” * Schimper, in 1874, gives a somewhat amplified diagnosis as follows: “ Frondes bipinnatim divise, pinnis patentibus, lobis seu pinnulis tota basi insidentibus, interdum confluentibus, raro breviter auriculatis, acuminatis vel obtusis, hic illic, preecipue apice, denticulatis, haud raro sursum subfalcatis ; nervo medio sat valido, nervis secundariis sub angulis acutis vel patentioribus orientibus, paulum supra basin dichotomis et repetito-dichotomis, tenuibus et tenuissimis.” * Later this author * abandons Cladophlebis in the belief that the fertile 1Saporta, Pal. France, ser. ii, Végétaux, Pl. Jurass., t. i, 1873, pp. 298, 299. -» Schimper, Pal. Végét. t. iii, 1874, p. 503. 5’ Schimper in Zittel’s Handbuch der Paleontologie, Abth. ii, 1890, pp. 99, 100. 16 240 SYSTEMATIC PALEONTOLOGY specimens described by Heer justify the reference of these forms to the modern genus Asplenium. The most recent diagnosis is that by Seward, which may appropriately be quoted for the American Cretaceous forms: “Fronds pinnately divided, pinne spreading, lobes or pinnules at- tached by the entire base or slightly auriculate, acuminate, or obtuse, occasionally dentate, especially at the apex, not rarely subfalcately curved upwards, midrib strong at base, and towards the summit dissolving into branches, secondary veins given off at a more or less acute angle, dichotomous a little above the base, and repeatedly dichotomous.” Much difference of opinion has prevailed regarding the unity and the systematic position of the genus, Saporta* having long ago pointed out that Brongniart’s Paleozoic species had nothing in common with those of the Mesozoic, and that the Liassic and Oolitic forms, those which the former author was discussing, give evidence of common characters. At the present time there is still lacking evidence from such fructified remains as have been discovered of close relationship between all of the various species of Cladophlebis. Thus Heer discovered in the Siberian Jurassic fragments of the Cladophlebis whitbyensis type with soral char- acters which he compared with those of the subgenus Diplazium of Asplenium,’ and Schenk has figured fertile pinnules of the same type in the case of the allied Asplenites resserti.. Certain specimens of the Jurassic species Cladophlebis lobifolia show that the sporangia in this species were apparently borne in semi-circular pocket-like depressions on the edges of the fertile segments,’ while the fructifications of Clado- phlebis denticulata are in the form of narrow, oblong sori parallel with the secondary veins, and are compared by Seward* with the modern forms Asplenium lugubre and Phegopteris decussata. In his latest utter- -ance on this subject he asserts that “there are fairly good grounds for 1Seward, Wealden Fl., pt. i, 1894, p. 88. 2 Saporta, Pal. France, ser. ii, Végétaux, Pl. Jurass., t. iv, 1888, p. 357. Heer, Fl. Foss. Arct., Band iv, 1877, p. 38, pl. xxi, figs. 3, 4. ‘Schenk, Fl. Foss. Grenz. Keup. Lias., 1867, p. 51, pl. vii, figs. 7, 7a. >’ Seward, Jurassic Fl. pt. i, 1900, tf. 23. ® Seward, loc. cit., p. 141. MaryYLAND GEOLOGICAL SURVEY 241 the assertion that some at least of the fronds described under this name are those of Osmundacew.”* Zeiller* has recently described a species from the Wealden of Peru, which he considers identical with or very close to Cladophlebis Browniana, in which the sporangia are biseriate, oval, and annulate as in the Schizmacem. These are said to be very like those of the Jurassic genus Klukia of Raciborski. In the Potomac flora we find that fourteen so-called species of Aspidium Swartz (Dry- opteris Adanson), mostly fertile fronds, were described by Fontaine in 1890. These showed mostly large elliptical or reniform sori in rows on each side of the midvein, and located generally on the distal branch of a furcate vein, usually wanting in the apical part of the pinnule. These were compared by this author with modern species of Aspidium, Cys- topteris, Polystichum, and Didymochiena. The preservation is not of the best, the matrix being coarse, and Fontaine’s figures are largely idealized. It has seemed remarkable that the fronds of Dryopteris in the Potomac beds were almost always fertile, while those of Cladophlebis in intimate association with them were invariably sterile. By careful comparison it has been possible to correlate the fertile specimens described as Dryopteris with the sterile Cladophlebis fronds of the same species in five of the types which are represented in the Potomac flora by sterile and fertile fronds, and the presumption is strong, although unverified, that the remaining Dryopteris forms repre- sent fertile fronds of Cladophlebis, although they are set apart in the present publication in the genus Dryopterites. While the foregoing facts are not in unison in regard to the systematic position of Cladophlebis they all point to the inclusion of the following American species in the family Polypodiaces, or what answered to this family in Lower Cre- taceous times, and cast some doubt upon Raciborski’s suggestion that Cladophlebis denticulata and other species of the same genus were the sterile fronds of Osmundaceous ferns. It is quite possible that ferns of more than one subfamily of the Polypodiacex, or, indeed, of other families, are included among the various described species of Cladophle- 1 Seward, Fossil Plants, vol. ii, 1910, p. 345. 2 Zeiller, Comptes rendus, tome cl, 1910, p. 1488. 242 SYSTEMATIC PALEONTOLOGY bis. It need but be remembered how many unrelated modern ferns have fronds of the Cladophlebis type, as, for example, certain species of Al- sophila, Asplenium, Cyathea, Dryopteris, Gleichenia, Onoclea, Osmunda, Polypodium, Pteris, etc., to cast doubt upon the botanical affinity of Cladophlebis species unless these are attested by a considerable body of evidence. It is believed, however, that the Potomac species are all to be included in the subfamily Dryopteridex, and because of this and also because their actual identity with the modern genus Dryopteris, or, in fact, with any of the modern genera in this subfamily is extremely ques- tionable, it has seemed wiser to use the more general name Cladophilebis instead of using Dryopteris, where the sterile and fertile fronds have been correlated. Possibly in the end a new generic name, such as Aspidiopteris, will prove to be the most satisfactory solution of the question. A large number of species of Cladophiebis have been described, two species, according to Arber, occurring in the Permo-Carboniferous of India. The genus appears in force in the Keuper and Rheetic, with more than a dozen recorded species. Over a score are recorded during the Jurassic, certain types, such as Cladophlebis denticulata, apparently be- coming world wide in their distribution. For the Lower Cretaceous Sa- porta has founded a large number of species based upon Portuguese material, and Fontaine has instituted a still larger number of American species. From the Potomac beds of Maryland and Virginia the latter author recorded 23 different species, besides several varieties of Clado- phlebis, altogether losing sight of variations and changes due to age, posi- tion of the fossils with regard to the frond as a whole, and changes due to the direct action of the environment. These were often based upon such insufficient material that it becomes almost impossible to deal with them with any degree of assurance. In considering all of the more representative material and including with it all of the forms recorded from Maryland, we have a total of eight species, and these eight species include remains which were the basis for twenty-three of Fontaine’s species and varieties of Cladophlebis, six of his species of Dryopteris, and nine of his species of Pecopteris. MARYLAND GEOLOGICAL SURVEY 243 CLADOPHLEBIS Browni1ana (Dunker) Seward Plate XXIX,. Figs. 1, 2 Pecopteris Browniana Dunker, 1846, Mon. Norddeutsch. Wealdenbildung, p. 5, pl. viii, fig. 7. Pecopteris Browniana Bronn, 1848, Index Pal., vol. ii, p. 914. Pecopteris Browniana Brongniart, 1849, Tableau, p. 107. Pecopteris Browniana Unger, 1850, Gen. et Sp., p. 176. Alethopteris Reichiana Ettingshausen, 1852, Abh. k. k. geol. Reichs., Band i, Abth. iii, p. 17. Alethopteris Reichiana Schimper, 1869, Pal. Végét., tome i, p. 569. Pecopteris Browniana Schenk, 1871, Paleont., Band xix, p. 215, pl. xxvi, fig. 2. ; Alethopteris ? Browniana Schimper, 1874, Pal. Végét., tome iii, p. 502. Pecopteris cf. Browniana Nathorst, 1890, Denks. K. Akad. Wiss., Wien, Band Ivii, p. 53, pl. v, fig. 5. Cladophlebis inequiloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 80, pl. xxv, fig. 8. Cladophlebis petiolata Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 80, pl. xxii, fig. 8. Cladophlebis oblongifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p: 74 (pars), pl. vii, fig. 5 (mon figs. 3, 4 which are referred to Cladophlebis virginiensis Font.) Cladophlebis crenata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 75, pl. ix, figs. 7-9; pl. x, figs. 1, 2; pl. xiii, figs.-1-3; pl. xix, fig. 7; pl. xx, fig. 6. Cladophlebis alata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 77, pl. xix, fig. 5. Cladophlebis sp., Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 78, pl. xix, fig. 2. Pecopteris strictinervis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 84, pl. xiii, figs. 6-8; pl. xix, fig. 9; pl. xx, fig. 3; pl. xxii, fig. 13; pl. clxx, figs. 5, 6. Pecopteris ovatodentata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 85, pl. xv, fig. 8; pl. xxii, fig. 12; pl. xxiii, fig. 1. 5 Pecopteris microdonta Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 85, pl. xix, fig. 8; pl. xx, figs. 5, 11. Pecopteris Browniana Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 88, pl. xxii, figs. 10, 11; pl. xxiii, figs. 2-7; pl. xxvi, figs. 3, 13. Pecopteris virginiensis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 82, pl. viii, figs. 1-7; pl. ix, figs. 1-6; pl. xxiv, fig. 2; pl. clxix, fig. 3. Pecopteris constricta Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 86, pl. xx, figs. 1, 2, 4. Pecopteris socialis Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 87, pl. xxi, fig. 7 (non Heer, 1882). 244 Systematic PALEONTOLOGY Pecopteris angustipennis Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 87, pl. xxi, fig. 10. Pecopteris Browniana Fontaine, 1892, Proc. U. S. Natl. Mus., vol. xv, p. 492. Pecopteris Browniana Dawson, 1893, Trans. Roy. Soc. Can., vol. x, sec. iv, p. 84, fig. 3. Pecopteris Browniana Saporta, 1894, Fl. Foss. Portugal, pp. 35, 78, pl. iv, figs. 11-13; pl. x, fig. 19; pl. xi, figs. 9, 10; pl. xii, figs. 2, 3; pl. xv, figs. 19, 29; pl. xvi, figs. 12, 16, 17, 19. Cladophlebis Browniana Seward, 1894, Wealden FI., pt. i, p. 99, pl. vii, fig. 4. Cladophlebis inclinata Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc. Am., vol. v, p. 450. Pecopteris Browniana Yokoyama, 1895, Journ. Coll. Sci., Imp. Univ., vol. vii, p. 218, pl. xxiv, figs. 2, 3; pl. xxvii, figs. 1-4, 5c, d. Pecopteris cf. virginiensis Yokoyama, 1895, Journ. Coll. Sci., Imp. Univ., vol. vii, p. 220, pl. xxiv, fig. 1. Cladophlebis Browniana Seward, 1908, Ann, S. Afr. Mus., vol. iv, p. 10, pl. ii, figs. 1-4, 6. Cladophiebis Browniana Fontaine, 1906, in Ward, Mon: U. S. Geol. Surv., vol. xlviii, 1905, pp. 272, 510, 517, 538, 544, 547, 557, 572. Cladophlebis crenata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xviii, 1905, p. 547. Cladophlebis alata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 229, 480, 510, 540, 544, 557, pl. xv, figs. 17-21. Cladophlebis inequiloba Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 510. Pecopteris virginiensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 480, 538, 552, pl. cxvi, figs. 3, 4. Pecopteris constricta Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 519. Cladophlebis Browniana Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, p. 108, pl. xi, fig. 1. Cladophlebis Browniana Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. xix, 1908, p. 386. Cladophlebis Browniana Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 312. Description——Dunker, the original describer of this species, defines it as follows: * Pecopteris fronde pinnata (bipinnata ?) pinnis lanceolatis, pinnulis linearibus apice obtusis adnatis, opposites et alternis, venis tenerrimis obliquis instructis ; rachi tenui.”—-Dunker, 1846. The American material which the writer refers to this species is much more abundant than that from abroad, and the foregoing diagnosis may be amplified in the following terms: . MARYLAND GEOLOGICAL SURVEY 245 Frond bipinnate or tripinnate. Pinne elongate, linear in outline.’ Pinnules approximate, variable in outline, usually obtuse and becoming united distad to form a pinnatifid pinna, which is then constricted and slightly decurrent at the base. Venation of the Cladophlebis type, not well seen in the smaller pinnules because of their coriaceous texture. This is another cosmopolitan species of Cladophlebis which may be composite in nature, and which, as commonly preserved in fragmentary specimens, is distinguishable with difficulty from its congeners. It is especially. close to Cladophlebis Albertsti and Cladophlebis Ungeri. It is recorded from the uppermost Jurassic and lowermost Cretaceous in Portugal, from the Neocomian of Japan and from the Wealden of Eng- land, Germany, and Austria. From the late Jurassic or early Cretaceous of Spitzbergen Nathorst describes a very similar form as Cladophlebis sp. B? ‘In America it has been reported from the Shasta through the Horsetown and in the base of the Chico formation on the Pacific Coast, and from the Kootanie formation of Montana and British Columbia. It is well scattered and abundant in the Potomac Group occurring in all three of the formations but represented for the most part by incom- plete specimens showing slight variations which were made the basis for many species by Professor Fontaine. Material from the Patapsco formation of Maryland shows indistinct oval sori in a single row on either side of the midvein. These are of the type found associated with a number of other American species of Cladophlebis. Professor Zeiller* has recently reported fertile fronds of Pecopteris Browniana, or of a very similar species from the Wealden of Peru. These are not figured but are described as having biseriate, oval, annulate sporangia, as in the modern family Schizeacew, and very like those of the Jurassic genus Klukia of Raciborski, thus apparently somewhat dif- ferent from those of the American representatives of the present species. 1The single form which Fontaine identified with this species has pinne which shorten rapidly giving the frond a deltoid form, and may be properly referable to the allied species Cladophlebis Ungeri. 2Nathorst, Kgl. Svenska Vetens.-Akad., Handl., Band xxx, No. 1, 1897, p. 50, pl. ii, fig. 10. 3 Zeiller, Comptes rendus, tome cl, 1910, p. 1488. 246 SYSTEMATIC PALEONTOLOGY Fragments from the Neocomian of Japan, showing oval sori, are referred to this species by Yokoyama (loc. cit.). Occurrence—PatuxENT Formation. Fredericksburg, Dutch Gap, Alum Rock, Telegraph Station (Lorton), Potomac Run, Virginia; New Reservoir, Ivy City, District of Columbia; Broad Creek (?), Maryland. ARUNDEL Formation. Arlington, Hanover, Howard Brown Estate, Maryland. Parapsco Formation. Brooke and vicinity, Chinkapin Hollow, Virginia; Federal Hill (Baltimore), Vinegar Hill, Maryland. Collecttons—U. 8. National Museum, Johns Hopkins University, Goucher College. CLADOPHLEBIS CONSTRICTA Fontaine Plate XXIX, Fig. 3 Cladophlebis ‘constricta Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 68, pl. ii, fig. 11; pl. iii, fig. 2; pl. vi, figs. 5, 6, 8-14; pl. xxi, figs. 9, 13; pl. clxix, fig. 2. Cladophlebis latifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 69, pl. iii, fig. 1; pl. vi, fig. 4. Cladophlebis. constricta Penhallow, 1905, Summ. Geol. Surv., Can., 1904, p. 9. Cladophlebis virginiensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 512, pl. exi, fig. 7. Cladophlebis constricta Fontaine, 1906, in Ward, Jbid., vol. xlviii, 1905, pp. 280, 297, 504, 528, 547, pl. Ixxi, fig. 26. Cladophiebis constricta Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, p. 109. Cladophlebis constricta Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 314. Description.—Frond large, bipinnate or tripinnate. Principal rachis rather slender. Pinne remote, shortening rapidly distad. Proximad they are pinnatifid, changing first into pinnules with undulate margins and then into those with entire -margins in passing toward the apex of the frond. Pinnules elliptical in outline, constricted at the base, which is rounded or subauriculate. Venation of the usual Cladophlebis type. This species has been identified at a number of localities in Maryland and Virginia, but it is not common at any of these. Outside this area it has been reported from the Kootanie of Montana, and very similar forms occur in the Kome beds of Greenland, as, for example, those which MaryYLaNnp GEoLoGgicaL SURVEY 247 Heer described as Pecopteris arctica; Pecopteris Andersoniana,’ and Pecopteris hyperborea.’ Abroad the species described by Schenk* from the German Wealden as Alethopteris cycadina is very close to the Ameri- can species, as Fontaine has already pointed out. Cladophlebis constricta exhibits considerable variation in the degree of remoteness and outline of the pinnules, and may possibly include more than one species, the fact that certain of these aberrant forms come from the low horizon at Fredericksburg, while all of the other occurrences are from Patapsco outcrops lends some credence to this suggestion. The species has been reported by Penhallow from the Kootanie in Canada, but this determination cannot be accepted with certainty. Occurrence.—PatuxENT Formation. Fredericksburg, Virginia. Pa- Tarsco Formation. Hell Hole (?), Brooke, Deep Bottom, Virginia; Federal Hill (Baltimore), Vinegar Hill, Ft. Foote (?), Maryland. Collection —U. S. National Museum. CLADOPHLEBIS ROTUNDATA Fontaine Cladophlebis rotundata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 78, pl. xx, figs. 9, 10. Cladophlebis brevipennis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 81, pl. xxxvi, fig. 1. ? Cladophlebis rotundata Penhallow, 1905, Summary, Geol. Surv. Canada, for 1904, p. 9. Cladophlebis rotundata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 491, 510. Cladophiebis rotundata Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 317. -Description.—*‘ Frond bipinnate or tripinnate, arborescent (?) ; prin- cipal rachis stout, rounded, and prominent; pinne short, with a strong rigid rachis; ultimate pinne, from the lower part of the frond, with al- ternate, short, broadly ovate, very obtuse, round-lobed pinnules, those of the upper part of the frond having the lowest pinnules distinct and more or less round-lobed, and towards the summit with pinnules passing through such forms as rotundate, subrhombic, and decurrent to entire +Heer, Fl. Foss. Arct., Band i, 1868, p. 80, pl. i, fig. 13; pl. xliii, fig. 5. 2 Heer, Ibid., Band iii, Abth. ii, 1874, p. 41, pl. iii, fig. 7, b. ® Heer, Ibid., Band i, 1868, p. 81, pl. xliv, fig. 4. 4Schenk, Paleont., Band xix, 1871, p. 218, pl. xxxi, fig. 2. 248 Systematic PALEONTOLOGY and rounded, the latter having the tips round-lobed and very obtuse; nerves varying according to the position and shape of the pinnules, those of the round-lobed pinnules and of the pinne reduced to pinnules flabel- lately diverging in each lobe, the branches being either forked or simple. The nerves of the subrhombic pinnules have a midnerve, which sends off alternately on each side forked or simple branches. All the nerves are very strongly marked and stout. The leaf-substance is thick and leathery.”—Fontaine, 1890. The foregoing description was written for Cladophlebis rotundata, but it requires no alteration to include the rare fragments which were named Cladophlebis brevipennis, as the material on which the two were founded is identical, in fact, the description of the latter was practically a para- phrase of the former. This species, while founded upon rather scant remains, is characterized by the strong venation and the breadth of the short ovate pinnules. It may possibly represent Cladophlebis constricta Fontaine, closely re- sembling the form of this latter species which Professor Fontaine named Cladophlebis latifolia. It has been recorded by Penhallow from Yukon Territory in Canada, but the identification is queried as being very doubtful. Occurrence—PatuxENT Formation. Fredericksburg, Dutch Gap, Virginia. Patapsco Formation. Mt. Vernon, Chinkapin Hollow, Virginia. Collection —U. 8. National Museum. CLADOPHLEBIS VIRGINIENSIS Fontaine Plate XXIX, Figs. 4-6 Asplenium distans Dawson, 1886, Trans. Roy. Soc. Can., vol. iii, sec. iv, 1885, p. 5, pl. iii, fig. 7 (non Heer). = Cladophiebis virginiensis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 70, pl. iii, figs. 3-8; pl. iv, figs. 1, 3-6 (non Fontaine, 1906). Cladophlebis falcata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 72, pl. iv, fig. 8; pl. v, figs. 1-6; pl. vi, fig. 7; pl. vii, figs..1, 2. Cladophiebis acuta Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 74, pl. v, fig. 7; pl. vii, fig. 6; pl. x, figs. 6, 7; pl. xj, figs. 7, 8; pl. elxvi, fig. 5. MARYLAND GEOLOGICAL SURVEY 249 Cladophlebis oblongifolia Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 74 (pars), pl. vii, figs. 3, 4 (non fig. 5 which is referred to C. Browniana). Thinnfeldia variabilis Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc. Am., vol. v, p. 450. Thinnfeldia variabilis Fontaine, 1896, in Stanton, Bull. U. S. Geol. Surv., No. 133, p. 15. ; Thinnfeldia montanensis Fontaine, 1898, in Weed and Pirsson, 18th Ann. Rept. U. S. Geol. Surv., 1896-97, pt. iii, p. 481. Cladophlebis acuta angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xIviii, 1905, p. 539, pl. exiv, fig. 5. Cladophlebis falcata montanensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 291, pl. lxxi, figs. 14-20. Cladophlebis falcata Fontaine, 1906, in Ward, Ibid., vol. xlviii, 1905, pp. 227, 280, 511, 548, pl. Ixv, figs. 12-14; pl. cxi, fig. 6. Cladophiebis acuta Fontaine, 1906, in Ward, Ibid., vol. xlviii, 1905, p. 538, pl. exiv, figs. 3, 4. Cladophlebis falcata Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. xix, p. 386:- -- Cladophlebis virginiensis Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 320. Description —F rond large, bi- or tripinnate. Rachis stout and rigid. Ultimate pinne long, rather remote, alternate to subopposite. Pinnules ovate to lanceolate and subfalcate in outline, sometimes obtusely pointed, mostly separate to the base, attached by their whole base which is more ‘or less widened. Venation of the type usual in this genus. Margins usually entire, sometimes crenulate to subdentate, becoming entire distad. Texture coriaceous. The degree of separateness of the pinnules, as well as their relative length and breadth and their more or less falcate form, are characters dependent upon the age of the frond or the position of the pinnules on the frond, long, narrow, almost straight proximal pin- nules passing gradually into more or less short, broad, and falcate distal pinnules. This species is-not very different from the widespread type of Clado- phlebis, commonly referred to the species Albertstt of Brongniart. It ex- hibits considerable variation from specimen to specimen, but these varia- tions show so many gradations aud are so readily explained when the position of the various fossil fragments upon the frond is taken into consideration that any segregation of them is entirely unwarranted. In general, the pinnules are larger and relatively much wider than in Cladophlebis Albertsi. 250 SYSTEMATIC PALEONTOLOGY The present species is very common at certain localities, both in the Patuxent and Arundel formations, and although it apparently survives during the deposition of the Patapsco formation it is less common. Out- side of the Maryland-Virginia area remains of this species have been re- ported from the Shasta beds of California, and from the Kootanie of Montana and British Columbia. Seward (Fossil Plants, vol. ii, 1910, p. 340) refers the bulk of Fontaine’s figures of Cladophlebis virgimensis Font. to Todites Williamsoni (Brongniart), a widespread older Jurassic species, but this reference has no justification. Cladophlebis Nathorsti Yokoyama, from the Neocomian of Japan, is very close to the Potomac species. Occurrence—PatuxENt Formation. Fredericksburg, Dutch Gap, Potomac Run, Virginia. ArunpEL Formation. Arlington, Maryland. Parapsco Formation. Vinegar Hill, Maryland; Chinkapin Hollow, Virginia. Collections.—U. 8S. National Museum, Goucher College. CLADOPHLEBIS PARVA Fontaine Plate XXVIII, Figs. 1, 2; Plate XXX; Plate XX XT Cladophlebis parva Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 73, pl. iv, fig. 7; pl. vi, figs. 1-3. Cladophlebis sp., Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 81, pl. xxvi, fig. 15. Aspidium heterophyllum Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv. 1889, p. 96, pl. xiv, figs. 1-5; pl. xv, figs. 1-5. Cladophlebis inclinata Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc. Am., vol. v, p. 450. Cladophlebis inclinata Fontaine, 1896, in Stanton, Bull. U. S. Geol. Surv., No. 133, p. 15. Aspidium heterophyllum Fontaine, in Diller and Stanton, loc. cit. Aspidium heterophyllum Fontaine, in Stanton, loc. cit. Dryopteris heterophylla Knowlton, 1898, Bull.. U. S. Geol. Surv., No. 152, p. 92. Cladophiebis parva Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 657, pl. clx, fig. 18. A Dryopteris heterophylla Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 483, 550, pl. exv, figs. 7, 8. *Yokoyama, Journ. Coll. Sci., Imp. Univ., vol. vii, 1895, p. 220, pl. xxviii, figs. 3, 4, 10, 11. MaryLanp GEOLOGICAL SuRVEY 251 Cladophlebis parva Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 225, 280, 510, 538, pl. lxv, figs. 5-8. Cladophlebis parva Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. xix, p. 386. Cladophlebis parva Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 316. Description—Fronds large, bipinnate or tripinnate. Rachis very stout. Pinne linear-lanceolate, becoming somewhat falcate in outline distad, and passing from alternate to subopposite. Pinnules relatively wide, falcate, acuminate in the sterile forms, but obtuse in the fertile, variable in size, according to their position, the distal pinnules which represent the reduced pinne lower down on the frond are larger and relatively more slender than the pinnules of the lateral pinne, which are almost as wide as they are long, and falcate. Between the two orders there is every gradation on each frond through pinnatifid pinne to simple pinnule-like forms. Margins entire or slightly crenate, especially in the fertile pinnules, which are wider than the sterile. Sori large, reniform in outline, in three or four pairs on either side of the midvein at the end of a distal branch of a furcate vein. The structure or arrangement of the sporangia cannot be made out, but the spores are preserved in abundance. They are small, ranging from .083 mm. to .05mm. in diameter, with very thick walls, the outer surface covered with fine granulations not visible with magnifications of 200 diameters or less. The tetrad scars are very distinct. In form as well as size these spores are variable, the smaller possibly immature spores are trigonal in out- line while the larger are more nearly spherical. Their varying appear- ance is well shown in those which are figured. Lateral veins usually but once forked, sometimes simple. Texture coriaceous. This is a large and handsome species and is represented in the col- lections by very fair material of both the sterile and fertile fronds. It ranges from the bottom to the top of the Potomac deposits and outside the Maryland-Virginia area is recorded from the Shasta beds of the Pacific Coast, the Kootanie of Montana and the Lakota formation of the Black Hills. There are a number of European Wealden species which are similar to Cladophlebis parva, but it is believed to be quite distinct from its contemporaries, although small fragments of almost any of the species of Cladophlebis are likely to be confused. 252 Systematic PALEONTOLOGY Occurrence—-PaTUXENT ForMATION. Fredericksburg, Cockpit Point, Potomac Run, Virginia. ARUNDEL Formation. Arlington (?), Mary- land. Pararsco Formation. Vinegar Hill, Maryland. Collections.—U. 8. National Museum, Goucher College. CLADOPHLEBIS ALBERTSII (Dunker) Brongniart Plate XXXII, Figs. 3, 4 Neuropteris Albertsiti Dunker, 1846, Mon. Norddeutsch. Wealdenbildung, p. 8, pl. vii, figs. 6, 6a. Cladophlebis Albertsii Brongniart, 1849, Tableau, p. 107. Neuropteris Albertsii Unger, 1850, Gen. et Sp., p. 83. Neuropteris Albertsii Ettingshausen, 1852, Abh. k. k. geol. Reichs., Band i, Abth. iii, p. 12. Alethopteris Albertsii Schimper, 1869, Pal. Végét., tome i, p. 570. Pecopteris Whitbiensis Trautschold, 1870, Nouv. Mém. Soc. Nat. Moscou, vol. xiii, p. 27, pl. xix, fig. 2. Alethopteris Albertsii Schenk, 1871, Paleont., Band xix, p. 218, pl. xxvii, fig. 4. Pteris ? Albertsii Heer, 1882, FJ. Foss. Arct., Band vi, Abth. ii, p. 29, pl. xvi, figs. 5, 6; pl. xxviii, figs. 1-3; pl. xlvi, figs. 22-24. Pteris Albertini Velenovsky, 1888, Abh. k. bohm. Ges. Wiss., Band ii, p. 15, pl. iv, figs. 6-10 (mon fig. 5). Cladophlebis inclinata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 76, pl. x, figs. 3, 4; pl. xx, fig. 8. Cladophlebis denticulata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 71, pl. iv, fig. 2; pl. vii, fig. 7 (non Nathorst). Cladophlebis sp., Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 77, pl. x, figs. 5, 8; pl. xx, fig. 7. Cladophlebis pachyphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 80, pl. xxv, fig. 9. Cladophlebis sp., Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 77, pl. xv, fig. 6; pl. xix, fig. 3. : Aspidium Oerstedi ? Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 99, pl. xix, fig. 4 (non Heer). Aspidium angustipinnatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 98, pl. xvi, figs. 1, 3, 8; pl. xvii, fig. 1; pl. xix, fig. 10. Cladophlebis Albertsii Seward, 1894, Wealden F1., pt. i, p. 91, pl. viii. Dryopteris angustipinnata Knowlton, 1898, Bull. U. S. Geol. Surv., No. 152, p. 91. Dryopteris Oerstedi ? Knowlton, 1898, Bull. U. S. Geol. Surv., No. 152, p. 92. Dryopteris angustipinnata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 540, 544, 548, pl. exiv, fig. 6. Cladophlebis Albertsti Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 310. MARYLAND GEOLOGICAL SURVEY 253 Description“ Neuropteris fronde pinnata (bipinnata ?) pinnulis tenuibus oppositis distantibus, sessilibus, oblongis, basi rotundatis vel subcordatis, apice attenuatis, subobtusis ; nervo medio crassiusculo, venis cereberrimis tenuissimis obliquis furcatis ; rhachi gracili tereti.”—Dunker, 1846. A large amount of material has been referred to this species since Dunker’s day, so that his diagnosis may be considerably amplified. In general these forms show the following characters: Fronds large bipinnate or tripinnate. Rachis stout. Pinne linear- lanceolate, alternate to subopposite, becoming pinnatifid distad. Pin- nules usually attached by their whole base, which is slightly expanded, contiguous but usually separated to the base, lanceolate, slightly falcate, acuminate. Margin usually entire, more rarely somewhat dentate in the apical portion. Venation of the usual Cladophlebis type. Fertile fronds have the rachis more slender than in the sterile fronds. The sori are borne on a distal branch of a furcate vein as in other Potomac species of Cladephlebis, and form a row on either side of the midvein of the pinnules, which are otherwise indistinguishable from the sterile pin- nules, though inclined: to be straighter. This species has been made to include a large amount of material from various horizons and localities, which in the first instance was described as various species of Neuropteris, Alethopteris, Pecopteris, Pteris, ete. It is not at all certain that the result may not be a com- posite species made up of several distinct species with indistinguishable vegetative characters, and it would not be difficult to select still other forms from various parts of the world which could scarcely be separated from the foregoing. Cladophlebis Albertsii was not recognized as such in Professor Fon- taine’s Potomac studies, but it is obvious that the forms described as Cladophlebis inclinata and Cladophlebis denticulata (this was described as a new species and is decidedly different from Brongniart’s species of the same name which Nathorst has referred to Cladophlebis), and as Aspidium angustipinnatum are identical with each other and with those ferns in the European Wealden which are referred to Cladophlebis Al- 254 SysTEMATIC PALEONTOLOGY bertsiz. The additional fragments of Potomac ferns which are referred to this species are not common and are equally unimportant botanically and stratigraphically. The two Cladophlebis sp., Fontaine, are clearly enough referable to this species. Cladophlebis pachyphylla is considered as an anomalous pinna with thicker more remote pinnules, which are contracted at the base. It was founded on a single fragment from Fred- ericksburg, Virginia, and if not an example of this species is simply a distal aberrant pinna of one of the other described species from that locality. The specimen which was the basis for the presence of Aspidium erstedi Heer in this flora is the merest fragment without significance in any way. The fertile pinne of Cladophlebis Albertsii agree with those of Cla- dophlebis parva and other Potomac species in the general character, form, and arrangement of the sori, the nature of the material precluding any more detailed information on this point. The sori appear to be confined to the basal part of the proximal pinnules. The present species is closely related to the contemporaneous form Cladophlebis virginiensis Fontaine. It is common in the Wealden of England and Germany, and probably in homotaxial or somewhat younger beds in Austria and Russia: It has been recorded from the Cenomanian’ of Bohemia and from the Atane beds of Greenland, but both of these determinations may be considered as very doubtful. Nathorst has described a similar form from Spitz- bergen as Cladophlebis sp. A. In this country it is definitely known only from the Potomac Group. It has been recorded from the Patapsco for- mation at Vinegar Hill, Maryland, but the single specimen is referred by the writer to Cladophlebis virginiensis, which is abundant at this locality. Occurrence—PaTUXENT ForMAtIon. Potomac Run, Telegraph Sta- tion (Lorton), Dutch Gap, Trents Reach, Fredericksburg, Virginia. ARUNDEL Formation. Arlington, Hanover, Bay View, Maryland. Collections—U. 8. National Museum, Goucher College. 1 Nathorst, Kgl. Svenska Vetens.-Akad. Handl., Band xxx, No. 1, 1897, p. 49, pl. ii, figs. 9, 11-13. MaryLAND GEOLOGICAL SURVEY 255 CLADOPHLEBIS UNGert (Dunker) Ward Plate XXXII, Figs. 1, 2 Pecopteris Ungeri Dunker, 1846, Mon. Norddeutsch. Wealdenbildung, p. 6, pl. ix, fig. 10. Pecopteris polymorpha Dunker, 1846, Mon. Norddeutsch. Wealdenbildung, p. 6, pl. vii, fig. 5 (non Brongniart). Pecopteris Ungeri Brongniart, 1849, Tableau, p. 107. Pecopteris Ungeri Unger, 1850, Gen. et Sp., p. 177. Pecopteris polymorpha Unger, 1850, Gen. et Sp., p. 177 (non Brongniart). Pecopteris Dunkeri Schimp., 1869, Pal. Végét., tome i, p. 539. Pecopteris Dunkeri Schenk, 1871, Paleont., Band xix, p. 214, pl. xxvi, fig. 1; pl. xxxi, fig. 1. Pecopteris exiliformis Geyler, 1877, Paleont., Band xxiv, p. 226, pl. xxx, fiz. 1, Pecopteris polymorpha Dupont, 1878, Bull. Ac. Roy. Belg., sér. ii, vol. xlvi, p. 387 (non Brongniart). Pecopteris exilis Yokoyama, 1890, Journ. Coll. Sci., Japan, vol. iii, p. 35, pl. i, figs. 8-10. Aspidium parvifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 100, pl. xxi, fig. 6; pl. xxiv, fig. 8; pl. xxv, fig. 10; pl. xxvi, figs. 1, 14, 16, 17. Pecopteris Geyleriana Nathorst, 1890, Denks. k. Akad. Wiss., Wien, Band lvii, p. 48, pl. iv, figs. 2-6. Pecopteris sp., Nathorst, Ibid., pl. vi, fig. 4. Pecopteris brevipennis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 86, pl. xxi, figs. 1-3. Pecopteris pachyphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 88, pl. xxvi, figs. 4, 5. Aspidium Dunkeri Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 101, pl. xxii, figs. 9, 9a, 9b; pl. xxv, figs. 11, 12; pl. xxvi, figs. 2, 8, 9, 18; pl. liv, figs. 3, 9. Aspidium Dunkeri Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc. Am., vol. v, p. 450. Pecopteris Dunkeri Saporta, 1894, Fl. Foss. Portugal, pp. 106, 169, pl. xix, figs. 10, 11; pl. xxviii, figs. 15, 16. Cladophlebis Dunkeri Seward, 1894, Wealden F1., pt. i, p. 100, pl. vii, fig. 3. Pecopteris Geyleriana Yokoyama, 1895, Journ. Coll. Sci. Imp. Univ., vol. vii, p. 219, pl. xxi, fig. 12; pl. xxiii, figs. 1, la; pl. xxxviii, fig. 5. Aspidium Dunkeri Fontaine, 1896, in Stanton, Bull. U. S. Geol. Surv., No. 138, p. 15. Dryopteris parvifolia Knowlton, 1898, Bull. U. S. Geol. Surv., No. 152, p. 92. ? Pecopteris Geyleriana Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 654, pl. elx, figs. 9-13. Cladophlebis Dunkeri ? Seward, 1900, Fl. Wealdienne de Bernissart, Mém. Musée d’hist. nat. Belgique, Année 1900, p. 24, pl. iii, figs. 35-40, 43-46, 51, 52. 17 256 SYSTEMATIC PALEONTOLOGY Cladophiebis Dunkeri Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xviii, 1905, pp. 510, 538. Dryopteris parvifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 486 (non p. 541, pl. cxiv, fig. 7). Cladophlebis Ungeri Ward, 1906, in Font., in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 228, 510, 538, pl. Ixv, figs. 15, 16. Pecopteris brevipennis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 510. Cladophiebis Ungeri Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. xix, p. 386. Cladophiebis Ungeri Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 318. Description.—“ Pecopteris fronde gracili bipinnata, pinnis petiolatis linearibus alternis, pinnulis adnatis opposite ovato-oblongis obtusis re- motiusculis, nervo obsoleto venisque obliteratis; rhachi tenui tereti.”— Dunker, 1846. A more extended and satisfactory diagnosis is that written by Profes- sor Fontaine for his Aspidium Dunkeri, which will answer not only for that material but for all of the other supposed species founded by Fon- taine upon various fragments of Cladophlebis Ungeri. It is as follows: “Frond bipinnate or tripinnate, arborescent; principal rachis stout and rigid; ultimate pinne alternate, short, linear-lanceolate; pinnules alternate or subopposite, short, closely placed, narrowed at the base, cut more or less deeply into lobes or teeth which are ovate or oblong, obtuse or subacute, very small, those of the fertile portions of the frond stand- ing nearly perpendicular to the rachis and having in each lobe or pinnule a simple lateral nerve which bears a sorus on its summit, those of the sterile and more common portions more obliquely placed, mostly sub- acute, with nerves in each lobe that fork simply in the upper ones, and in the lower ones are composed of a midnerve with alternate simple branches; leaf-substance thick; sori very minute, club-shaped or ellip- tical, visible distinctly only with the help of a lens, and present only in the pinnules of the lower part of the pinn&, and mostly found on the lobes towards the base of these.” This species was described by Dunker in 1846 from the Wealden of northern Germany as Pecopteris Ungert and Pecopteris polymorpha. Schimper in 1869 renamed the latter Pecopteris Dunkeri as the specific MarYLAND GEOLOGICAL SURVEY 257 name polymorpha had been used by Brongniart in 1828. Schenk two years later, with Dunker’s original specimens before him, announced that Dunker’s Ungeri and polymorpha were synonyms. He did not, however, restore Dunker’s name nor has Seward done so in his discussion (1894) of this species in the Wealden flora. In accordance with the prevailing system of nomenclature Dunker’s original name must be used for this species, and this proposal was made by Ward in 1906. Seward in 1894 referred the species to the genus Cladophlebis, and while the American material available in the present treatment of this species is not as com- plete as might be desired it furnishes some evidence regarding the fertile fronds of still another species of Cladophlebis. The character of the fertile material is rather vague, and while it is clearly congeneric with a number of other of Fontaine’s species of Aspidiwm, it is hardly sufficient evidence of their relationship with that modern genus. The present species is close to Cladophlebis Browniana, and is apparently a cosmopol- itan Lower Cretaceous type, since indistinguishable material occurs not only in the English and Continental Wealden deposits (Belgium, Ger- many, Austria), but in the Neocomian of Portugal and Japan, and in the Uitenhage series of South Africa. Material from Japan shows ob- scure fruiting fragments in which the pinne are narrowed, and there is apparently a single sorus to each pinnule (Nathorst, loc. cit., pl. iv, figs. 3-5, of these fig. 3 is referred to Weichselia Mantelli by Seward, 1894). The species is also reported from the Albian of Portugal by Saporta. In America it is not rare in the Potomac beds, and rather doubtful remains are referred to this species from the Shasta beds of California and from the Fuson formation of the Black Hills area. It is probably represented in the Kootanie formation of Montana by Dry- opteris montanense (Font.) Knowlton.’ Prof. Seward in a recent paper (1903, op. cit.) expresses his belief that this species is identical with Cladophlebis Browniana, such differences as are observable being merely individual and not specific. This may well be the case, the two are certainly closely allied. There is, however, a serious danger involved 1Fontaine, Proc. U. S. Natl. Museum, vol. xv, 1892, p. 490, pl. Ixxxii, figs. 1-8; pl. Ixxxiii, figs. 2-8a. 258 SYSTEMATIC PALEONTOLOGY in uniting under a single specific name fern fronds from all quarters of the globe which closely resemble each other, and probably future study will show that even the present treatment is faulty in this particular. Occurrence.—PatuxENt ForMATION. Woodbridge, Fredericksburg, Dutch Gap, Telegraph Station (Lorton), Virginia. Patapsco Forma- tion. Chinkapin Hollow, Virginia. Collection.—U. S. National Museum. CLADOPHLEBIS DISTANS Fontaine , Plate XXXII, Figs. 5, 6 Cladophlebis distans Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 77, pl. xiii, figs. 4, 5. Aspidium fredericksburgense Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 94, pl. xi, figs. 1-6; pl. xii, figs. 1-6; pl. xvi, fig. 9; pl. xix, figs. 6, 7. % Dryopteris fredericksburgensis Knowlton, 1898, Bull. U. 8S. Geol. Surv., No. 152, p. 92. Cladophlebis distans Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 280, 572. Dryopteris fredericksburgensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 280, 512, 538, 548, pl. exii, fig. 2. Aspidium fredericksburgense Penhallow, 1908, Trans. Roy. Soc., Can. (iii), vol. i, sec. iv, p. 307. Cladophlebis distans Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 315. Description.—Frond large and coarse, bipinnate or tripinnate. Ra- chis very stout and rigid. Pinne of the ultimate order mostly alternate, rarely opposite or subopposite, with rigid and proportionally rather slen- der rachises, very long, linear. Pinnules alternate, oblong or ovate, ob- tuse, slightly faleate, and usually with a somewhat rounded and slightly constricted base, separate, more or less remote, in some specimens those of the lower pinne with crenate margins, those of the upper ones entire, passing in the middle part of the frond through pinnules with undulate margins. Leaf-substance thick and leathery. Midvein of the usual Cladophlebis type, that is, strong at base and dissolving into branches ‘at the summit; lateral veins of the crenate and undulate pinnules in groups in each tooth, composed of a midvein which sends off alternate simple branches, or else of forked veins with one of the branches forking again; those of the pinnules with entire margins ‘usually once forked, all quite distinct; fertile specimens rare. Sori very large, elliptical or MaryLAND GEOLOGICAL SURVEY 259 reniform in shape, and distributed in two rows, one on each side of the midvein, attached to the summit of the upper branch of a furcate vein. This species is quite generally distributed throughout the Potomac formations, although there is but one recorded occurrence from the Arundel formation. It is abundant in the Patuxent formation at Fred- ericksburg, and outside the Maryland-Virginia area it has been recorded from the Kootanie formation of Montana and British Columbia and the Shasta of the Pacific coast province. The sterile and fertile pinne are closely similar in outline and vena- tion, the former being much more abundantly represented than the latter. They are both very similar to those of Cladophlebis parva Fon- taine, and may be compared with a number of European and Kome species of Cladophlebis, Alethopteris, Pecopteris, etc. Occurrence-—PatuxENt Formation. Fredericksburg, Dutch Gap, Telegraph Station (Lorton), Virginia; Broad Creek, Maryland. Arun- DEL Formation. Arlington, Maryland. Pararsco Formation. Chink- apin Hollow, Virginia. Collection—U. S. National Museum. - Genus DRYOPTERITES gen. nov. The desirability of an additional form-genus for the reception of the fossil remains of ferns which resemble those of the recent genus Dry- opteris of Adanson,' but fail to furnish conclusive diagnostic characters, is obvious. The probability of a large and dominant modern genus like Dryopteris preserving its generic integrity when traced back to a time as remote as the Lower Cretaceous is altogether unlikely and the number of other modern genera with species whose foliar characters are similar to some of the many modern species of Dryopteris is another reason for abandoning the modern name for the Lower Cretaceous forms, and a third reason might be furnished by the action of the last International. Botanical Congress which decided.to “ conserve” the name Aspidium of Swartz,’ although Adanson’s name for these modern forms preceded it. by more than the span of a generation. 1 Adanson, Fam. PI., vol. ii, 1763, p. 20. ; 2? Swartz. Schrad, Jour. Bot., vol. ii, 1800, p. 4. 260 SYSTEMATIC PALEONTOLOGY The genus Dryopterites may be defined as follows: Fronds large,bi- or tripinnate or pinnatifid, pinnules dentate, crenate, lobate, or entire, attached by their whole base or slightly constricted basally. Venation of the Cladophlebis type, the single midrib becoming attenuated distad by the branching off of numerous simple or forked lateral veins. Sori not elongated, but elliptical, circular or reniform in outline, borne in a single row on either side of the midvein toward the end of a lateral vein or on a distal branch of a lateral vein. Minute structure not discernible. The genus Dryopteris has upwards of four hundred existing species of wide geographical distribution and consequent difference in size, form, and habit. Of these about 25 occur in North America. The fossil species which have been referred to Dryopteris number upwards of fifty forms and include about 18 from the Lower Cretaceous, six from the Upper Cretaceous, and about twenty from the various Tertiary horizons. Schimper,’ in 1869, in treating the then known fossil species, referred to Aspidium, as Dryopteris was then called, refers all but two from the relatively recent Upper Miocene (Tortonian) to the form genus Pecop- ters. The eighteen species just mentioned from the Lower Cretaceous in- clude fourteen from the Potomac Group, which Professor Fontaine so identified. These have been found in a number of instances to be iden- tical with remains referred to Cladophlebis, with which they have been united whenever the evidence warranted such a course. After this proc- ess of elimination there remained the following six, more or less illy defined, types which are here referred to Dryopterites, as indicative of their resemblance both in form and soral characters, as far as these are decipherable, to Dryopteris. The writer is strongly of the opinion that the following forms are closely allied to some of those which are discussed under Cladophlebis, and perhaps several are identical with such forms. The materials are; however, so scanty, poorly preserved, and inconclusive that a conserva- tive course demands that they be kept separate. 1Schimper, Pal. Végét., tome i, 1869. MARYLAND GEOLOGICAL SURVEY 261 Regarding the botanical relations of the following forms, there is little doubt of their being included with propriety in the Polypodiacez, or in that assemblage of ferns which represented this family in Lower Cretaceous time. DRYOPTERITES MACROCARPA (Fontaine) Aspidium macrocarpum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 103, pl. xvii, fig. 2. Dryopteris macrocarpa Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 92. Description-— Sterile frond not seen; fertile frond showing only a skeleton imprint; principal rachis stout and rigid; plant most prob- ably arborescent; rachis of the ultimate pinne stout and rigid; shape and dimensions of the pinnules not disclosed ; apparently large, elongate- oblong, attached by the entire base, alternate; midnerve rather slender, straight; lateral nerves simple, and bearing at their summits the sori arranged in a row on each side of the midrib. The sori are very large, reniform in shape, and seem to have been situated near the margin of the pinnules. Under a good lens the sporangia may be seen arranged often in a band near the matgin of the sori.”—Fontaine, 1890. No new material identical with this type has been subsequently col- lected. The fern seems to have been a large one and the type material is too poorly preserved to justify the description of the shape of the sorus or the arrangement of the sporangia. It is very probable that ‘this form is identical with one or the other of the fertile forms referred by the writer to Cladophlebis distans Fontaine, Cladophlebis parva Fontaine, and Cladophlebis Alberisit (Dunker) Brongniart, the latter being an especially probable affinity. Occurrence.—PaTUXxENT Formation. Dutch Gap, Virginia. Collection.—U. S. National Museum. DRYOPTERITES PINNATIFIDA (Fontaine) Aspidium pinnatifidum Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 101, pl. xxi, fig. 15. Dryopteris pinnatifida Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 92. 262 SYSTEMATIC PALEONTOLOGY ‘Description.—< Frond unknown; probably bipinnatifid; reduced pin- ne or pinnulés, linear, cut pinnately nearly to the rachis into ovate-falcate obtuse lobes or pinnules; leaf-substance thick and leathery; sori in a row on each side of the midrib, elliptical in shape and small, placed on the simple lateral nerves within the margin of the lobes.”—Fontaine, 1890. This so-called species is based on very rare and fragmentary material and is undoubtedly identical with other material referred to this genus or-to Cladophiebis. Professor Fontaine compared it with Didymochlena, but it is absolutely worthless for either stratigraphic or botanical pur- poses. ‘Occurrence.—Patarsco Formation. Bank near Brooke, Virginia. Collection —U. 8. National Museum. DRYOPTERITES CYSTOPTEROIDES (Fontaine) Aspidium cystopteroides Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 99, pl. xvi, fig. 2. Dryopteris cystopteroides Knowlton, 1898, Bull. U. S. Geol. Survey, No. % 152, p. 91. _ Description.— Sterile fronds not seen; rachis of ultimate pinne slender; pinnules alternate, attached by the middle portion of the base, crenately toothed, obtuse; sori rather large, in two rows, one on each side of the midrib, placed near the margin, on the summit. of the upper- most branch of the nerves; subglobose in shape, similar to those of Cystopterts, with an inflated indusium at base; nerves branching palm- ately in each tooth.”—-Fontaine, 1890. No new material is available for study. It is probably identical with what is here called Dryopterites virginica. Occurrence.—PaTUXENT FORMATION. Fredericksburg, Virginia. Collection—U. 8. National Museum. DRYOPTERITES ELLIPTICA (Fontaine) - Aspidium ellipticum Fontaine, 1890, Mon. U. 8S. Geol. Survey, vol. xv, 1889, p. 95, pl. xiii, figs. 9, 10. ‘ : . Dryopteris elliptica Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 92. Description.— Frond bipinnate or tripinnate, arborescent; rachis of the principal pinna stout and rigid; ultimate pinne alternate, short, MarybLanp GEoLogicaL SURVEY 263 oblong-lanceolate, terminating in an elliptical obtuse pinnule or lobe, which is similar to the pinnules lower down on the pinna; lower pin- nules distant, elliptical in shape, obtuse, attached by the middle of the much narrowed base, or by the midnerve alone; upper pinnules attached by the entire widened base; uppermost ones united towards the tip of the pinne ; all very thick and leathery in texture; lateral nerves not dis- tinct, but apparently simple, and bearing the sori on their summits; sori pear-shaped or truncate-elliptical, in two rows, one on each side of the midnerve; sterile forms not seen.”—Fontaine, 1890. No new material is available for study and the type material is very poor. While it is probable that this does not represent a distinct species no definite conclusion is possible without more abundant and better pre- served material. Occurrence.—PaTUXxENT Formation. Near Potomac Run, Virginia. Patapsco Formation. Near Brooke, Virginia. Collectton.—U. 8. National Museum. DRYOPTERITES DENTATA (Fontaine) Aspidium dentatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 102, pl. xxv, figs. 6, 7, 14, 15. Aspidium microcarpum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 103, pl. lix, figs. 2, 12; pl. lx, figs. 6, 7. Dryopteris dentata Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 91. Dryopteris microcarpa Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 92. Description—* Frond. tripinnate; principal rachis comparatively ‘stout and rigid; ultimate pinne alternate, very short, linear-lanceolate ; pinnules membranaceous, alternate, lower ones separate to the base, upper ones united and reduced to lobes; lower pinnules broadly ovate, acute, narrowed to the base, and subpetiolate, cut nearly to the midnerve into ovate, acute teeth, reduced in the upper part of the compound pinne to ovate, obtuse lobes and teeth; sori very small, subreniform or globose, placed within the margin on the summit of the alternate simple lateral nerves; nerves in each of the pinnules and lobes, composed of a mid- nerve, with simple alternate lateral ones on each side; in the uppermost 264 SYSTEMATIC PALEONTOLOGY lobes the nerves become one or more times forked, without a midnerve.”— ‘Fontaine, 1890. The foregoing description is that of Aspidium dentatum, but it applies equally well to Aspidiwm microcarpum. It is curious that these two supposed species, both present in the same outcrop and identical except for the fact that in the one case they were sterile and in the other showed traces of sori, should have been made the basis of two distinct species. The reference of the Dutch Gap specimens here is not above question. Occurrence.—PAtuUXENT Formation. Dutch Gap, near Potomac Run, Telegraph Station (Lorton), Virginia. Collection.—U. 8S. National Museum. DRYOPTERITES VIRGINICA (Fontaine) Aspidium virginicum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 97, pl. xv, fig. 14. Aspidium oblongifolium Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 100, pl. xxi, fig. 5. Dryopteris virginica Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 93 (non Fontaine, 1906). Dryopteris oblongifolia Knowlton, 1898, Bull. U. S. Geol. Survey, No. 152, p. 92. Description“ Frond bipinnate or tripinnate; arborescent ?; rachis of the principal pinna stout and rigid; pinne of ultimate order reduced to pinnules in the terminal portions of the penultimate pinne, alternate, linear-lanceolate, passing through pinnately lobed pinne into pinnules with entire margins; leaf-substance thick and leathery; nerves slender, immersed in the leaf-substance, and seen with difficulty; pinnules of the lower pinne opposite, separate to the base; attached by the entire base, elongate oblong, subacute, with denticulate margins; sterile form of the frond not seen; sori comparatively small, reniform, in two rows, one on each side of the midnerve of the pinnules, and placed at the sum- mit of the upper branch of a forking nerve.”—Fontaine, 1890. The description quoted is that of Aspidium virginicum, but it fits the species as emended here, the form previously described as Aspidium oblongifolium being entirely inadequate for framing a description. The two are clearly identical. The occurrence of this species at the locality near Brooke, which is within the Patapsco formation, is queried, since i MaryLANpD GroLocicaL SuRVEY 265 the material is indecisive and the forms identified by Professor Fontaine (1906) as this species from the Mt. Vernon beds, which are of Patapsco age, prove to be identical with what Professor Ward named Scleropteris vernonensis, which in turn‘is not a Scleropteris, but by the character of _ its fertile fronds is related to Dicksonia. Occurrence-—PATUXENT ForMaATIoN. Near Potomac Run, Virginia. Patapsco Formation. Near Brooke (?), Virginia. Collection—U. 8. National Museum. Genus ASPLENIOPTERIS Fontaine [Mon. U. S. Geol. Surv., vol. xv, 1890, p. 117] This genus was characterized in the following terms by its describer: “Frond bipinnate or tripinnatifid; pinnules linear-lanceolate, or ob- long, acute to obtuse, lobed or toothed, sori proportionally very large, elongate to narrowly elliptical, in a row on each side of the midrib, one in each lobe or tooth, inserted on thick supports or segments, which represent the transformed segments or lobes, placed on the anterior mar- gin of these, and running down nearly their entire length.” The foregoing diagnosis unduly emphasizes the thickening of the fer- tile lobes, which are but little, if any, thickened. Professor Fontaine compares the genus with Dicksonia clavipes Heer, but there is little in’ common between the two. The Potomac forms are very poorly preserved, and in some respects they suggest the fertile parts of Onychiopsis. How- ever, after a thorough canvas of the Filicales, the writer has decided to retain the genus in the tribe Asplenies. No additional soral characters could be made out and no traces of spores were found. ASPLENIOPTERIS PINNATIFIDA Fontaine Plate XXVIII, Figs. 5, 6 Aspleniopteris pinnatifida Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 118, pl. xxii, figs. 1-3, 6, 7 (non Fontaine 1894, 1896). Description —“ Frond tripinnatifid; rachis of the primary pinna or of the frond very stout, rigid, and straight; pinne: or pinnules alternate, varying much in length according to position, with strong, rigid rachises ; 266 Systematic PALEONTOLOGY sterile pinnules linear-lanceolate, subacute, lower ones very long, much diminished in length in ascending, cut more or less deeply into crenate and rounded teeth and lobes; lateral nerves in each lobe flabellate diverg- ing, with the branches forked or simple, nerves very strong and distinct; fertile pinne or pinnules very long, with strong, rigid rachises, linear, subacute; lobes or teeth reduced to thick leathery supports, which bear the narrowly elliptical sori on the anterior face; the sori very long, al- most as long as the lobes, standing one in each lobe, apparently included between the two branches of a nerve that forks at the insertion.”—Fon- taine, 1890. The foregoing description should be modified by eliminating ‘the fan- cied thick soral peduncles which do not exist. As Professor Fontaine has pointed out there is no adequate proof that the sterile and fertile specimens belong to the same species. The species is an insignificant element in the oldest Potomac, and none other than the type material has been collected. The accompanying plate is from a photograph of the specimen which formed the basis for Fontaine’s idealized fig. 6 on pl. xxii of the Potomac flora (loc. cit.). The specimen is poor, the matrix being coarse, and the fern is represented by a brownish impres- sion showing merely the outlines. No minute characters or spores could consequently be made out. In some respects the fertile pinne suggest those of Onychiopsis, the pinnules are less reduced, however, and the sori appear to be single. The sori are thick and about 3mm. in length by a trifle under 1mm. in width. This species was doubtfully listed from the Shasta by Diller and Stanton in 1894,’ and by Stanton * in 1896, on the authority of Profes- sor Fontaine, who afterward described the material as a new species of Dicksonia.’ Occurrence.—PaTUXENT Formation. Fredericksburg, Virginia. Collection—U. 8. National Museum. ‘Diller and Stanton, Bull. Geol. Soc. Am., vol. v, 1894, p. 450. ? Stanton, Bull. U. S. Geol. Surv., No. 1338, 1896, p. 15. * Fontaine in Ward, Mon. U. 8S. Geol. Surv., vol. xlviii, 1906, p. 224, pl. lxv, fig. 1. BS r MaryYLanp GEoLogicaL SuRVEY 267 ASPLENIOPTERIS ADIANTIFOLIA Fontaine Aspleniopteris adiantifolia Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 118, pl. xvi, fig. 6. Description.—* Sterile frond not seen; fertile frond bipinnate or bi- pinnatifid; pinnules or lobes reduced to leathery thick pedicels or sup- ports, which bear on their anterior or upper margin narrowly elliptical or oblong sori; sori proportionally very large.”—Fontaine, 1890. This species was based upon the single specimen figured by Fontaine, which is so poorly preserved that it has not been refigured. It was -found in association with the preceding species, and it seems very prob- able that it represents merely a poorly preserved and perhaps abortive or pathological fertile pinna of the former. Occurrence—PaTUXENT ForMaTIoN. Fredericksburg, Virginia. Collection —U. S. National Museum. Genus ONYCHIOPSIS Yokoyama [Jour. Coll. Sci., Japan, vol. iii, 1890, p. 26] Yokoyama characterized this genus as follows: “ Fertile segments different from the sterile. Sori terminal, linear, on each side of the midrib, parallel with the margin, involucrate; the involucrum of each side confluent over the midrib.” It was based on a Japanese Jurassic species originally described by Geyler as Thyrsopteris elongata and founded upon sterile pinnules. The discovery of fertile pinnules by Yokoyama led to the erection of the present genus, which is very close to the modern genus Onychium Kaulfuss, which is made a subgenus of Cryptogramme R. Brown by Diels in Engler and Prantl’s Natiirlichen Pflanzenfamilien (1899), although there seems to be but slight warrant for Diel’s treatment. Seward, in working over the abundant Wealden material in the British Museum, found that the widespread species which usually went by the name of Sphenopteris Mantelli Brongniart was congeneric with Yoko- : yama’s species mentioned above, and he therefore redegcribed Bron- gniart’s species as Onychiopsis Muntelli, redefining the genus in the fol- lowing terms*: “ Frond tripinnate, main rachis slender, may be winged, 1 Seward, Wealden F1., pt. i, 1894, p. 40. 268 Systematic PALEONTOLOGY pinne alternate, approximate, lanceolate. Pinnules narrow, lanceolate, acute, alternate, the larger ones serrate, and gradually passing into pin- nules with narrow ultimate segments. Fertile pinne with alternate elliptical pinnules which differ in shape from the sterile pinnules and have the sporangia on the lower surface, giving them the appearance of raised elliptical bodies.” The most abundant and characteristic ferns of the Potomac Group » were referred by Professor Fontaine to Thyrsopteris Kuntze, an existing monotypic genus of the family Cyatheacee inhabiting the island of Juan Fernandez. Of these some forty species, so called, were described. They were all based on sterile fronds or parts of fronds, often extremely small and inadequate fragments. Professor Fontaine, after quoting Heer’s diagnosis of Thyrsopteris, writes: “his description, given by Heer for the genus Thyrsopteris, so far as the portion pertaining to the sterile frond is concerned, agrees well with a large number of species in the Potomac flora. These I place provisionally in the genus Thyrsopteris, on account of the great re- semblance that the shape of the pinnules, the lobing, and the nervation show to the sterile forms of various species determined to be Thyrsopteris by their fructification. As, however, no fructification is found in the Potomac’ species, the placing of these plants in the genus must be re- garded as provisional. It is quite possible that some of them belong to Aspidium and Dicksonia. The genus Thyrsopteris seems to be eminently a Jurassic type of fern. However, it may prove to be with the fructifi- cation of the various species assigned in this memoir to this genus, it is probable that they are at least distinct and true species. The great va- riety and comparative abundance of these forms show that this type was developed in the Potomac flora to an unusual degree. They surpass all other types, even that of Cladophlebis, and give a decided Jurassic facies to the assemblage of ferns found in this flora. Even if we cannot by fruc- tification determine the affinities of fossils with living plants, the large development of sterile forms of well-marked types is of importance in fixing the character of a flora. It should be noted that a number of *Heer, Fl. Foss. Arct., Band iv, Abth. ii, 1877, p. 28. MARYLAND GEOLOGICAL SURVEY 269 the species of Thyrsopteris described in the following pages show a good many features similar to those of Sphenopteris Mantelli, as described by Schenk and Heer” (p. 120). Professor Fontaine does identify Sphenopteris Mantelli from one lo- cality in the Potomac belt, that at Federal Hill, Baltimore, and in dis- cussing its bearing upon the age of the deposits he says: : “Now in the Potomac flora not only is S. Mantelli present in beds which show plants of the most recent facies existing in the formation, but there is a very important group of ferns which, although placed in the genus Thyrsopteris, have nearly the nervation and foliage typified in S. Mantelli. The great development in the Potomac of ferns of the general type of S: Mantelli gives strong evidence of Wealden or some- what later age. A somewhat later age than Wealden is indicated, per- haps, as most of the species are somewhat modified, so as to depart more or less from the typical 8. Mantelli, and to assume the facies of Thyrsop- teris. The other species of Sphenopteris give little help in fixing the age of the Potomac strata” (p. 338). Thus while the most prominent fern element in the Potomac Group belongs to a different genus and different family, its resemblance to the Sphenopteris Mantelli type is so pronounced that it furnishes an argu- ment for the nearly homotaxial age of the containing deposits, surely a curious logic. In his latest work this author identifies a species of Onychiopsis from three localities in Virginia and Maryland (Hell Hole, 3 sp.; New Reservoir, 1 sp., and Fort Foote, 2 sp.). Again, in discussing Thyrsopteris at the end of his Potomac flora (1890), he writes: “It is true that, as no fructification has been found on these ferns, they may be incorrectly placed in the genus Thyrsopteris. Still, the very great development in the Potomac flora of ferns with a foliage and nervation so characteristic of the later Jurassic and Lower Cretaceous cannot be without significance. This type of fern is much the most common in the Potomac strata. The species, most of them well characterized, number forty. They are distributed over the whole of the Potomac area, and a number of them are among-the most common ferns at the localities yielding them. This group, more than any other, 270 Systematic PALEONTOLOGY tends to give a Mesozoic facies to the Potomac flora. They have almost or quite passed away in the interval between the time of the deposition of the lower Potomac and that of the oldest Cretaceous of New Jersey. Their absence in the flora of the latter group greatly adds to the com- paratively recent aspect of this latter. A number of these Thyrsopterids have the same type of foliage as the Wealden ferns, Sphenopteris Man- telli Brongn.; S. Gepperti Dunker; 8. cordai Schenk; 8. plurinervia Heer; and S. Goinesiana Heer, as, well as the Urgonian plants Asple- nium Dicksonianum Heer; A. Nauckhofianwm Heer, and various Dick- sonias, such as D. Johnstrupi Heer. It is a significant fact that this type of foliage, so common towards the close of the Jurassic and in the oldest Cretaceous, is the most abundant single type in the Potomac strata also. Such a general prevalence of a type is more significant of geological relationship than the identification of a few species common to two formations. It is not worth while to examine in detail the affin- ities of the different species. Most of them are new and unique. One or two have some resemblance to Oolitic species, while a greater number may be grouped as belonging to the two Wealden types 8. Mantelli and S. Gepperti.” It will be seen from these lengthy quotations how uncertain the author of these forty species of Thyrsopteris was of their real botanical affinity, and when the student turns from the text and figures to the actual speci- mens, the strictures of Professor Seward (Wealden FIl., pt. i, 1894. p. 56 et seg.) are abyndantly justified.. There are twenty-six species de- seribed from a single clay lens at Fredericksburg, Virginia. If the reader will pause to ask himself where in the history of the earth or in the living flora twenty-six species of a single genus of ferns can be found © in a single circumscribed clay lens or growing in a single circumscribed area, grave doubt as to their validity at once arises, and even if we predi- cate their having been gathered together by a river system it must needs have been a remarkable river system to have gathered together all of these ferns along with over fifty other species of ferns and fifty species of gymnosperms, in all one hundred and sixty different species, and de- posited them in one quiet pool where clay was forming, a pool not over _ MarYLAND GEOLOGICAL SURVEY 271 15 feet in diameter as preserved and only 4 feet thick, the recognizable remains practically all coming from the basal 3 to.5 inches. With the large amount, of material at his disposal the writer finds 2 altogether impossible to differentiate the forty species described by Pro- fessor Fontaine from the Potomac Group. There are two main types, the narrow pinnule type, that identified in some of the Baltimore specimens as Sphenopteris Mantelli by Fontaine, and including some of the forms described as new species of Thyrsopteris, and the broader type exemplified ‘by the foreign Sphenopteris Gepperti. It is to the latter that a large number of the Potomac forms belong. Three additional species, which include the balance of the Thyrsopteris forms, are characterized. In perusing the synonymy of the species which follow, the question is likely to rise in the mind of the reader whether or not the process of ignoring minor differences has not been carried too far, so that it is needful to point out the reasons which have led to the present treatment. The main reason is, of course, that it was found impossible to fix upon any char- acters of specific value that would hold good for material other than the individual specimen upon which they were based. That the author of these species could not tell them one from the other is quite obvious in looking over the material which passed through his hands, specimens identical in all particulars at one time receiving one name and:on a subsequent occasion another, even counterparts of the same specimen being, in at least one instance, identified as distinct species. These ferns were of large size with tripinnate fronds, so that it is easy to see how one or two species with slight individual variations in form could, when broken up into fragments and fossilized in a matrix for the most part of very arenaceous clay, form the basis for numerous species. The pinne from the base of the frond will differ more or less from those higher up and the basal. pinnules of the individual pinne will differ decidedly from the distal ones.. It is possible in the more complete Potomac specimens to trace these variations and so get a num- ber of Fontaine’s types on a single specimen. It therefore seems wiser to consider the bulk of the forms as exemplifying slight variations, due largely to position, rather than to allow them specific or even varietal 18 272 SYSTEMATIC PALEONTOLOGY rank. The published drawings of these forms, especially the enlarged pinnules showing detail, are for the most part inaccurate and idealized to such an extent, or are composites so that even the experts in the National Museum often find it impossible to decide which specimens represent Fontaine’s drawings. With regard to our taking up the genus Onychiopsis of the Polypodi- acee rather than Thyrsopteris of the Cyatheacee it may be said that while Thyrsopteris, as a strictly form-genus, may not be open to any great degree to criticism, it implies a relationship with the existing species which the evidence does not substantiate, so that the best modern usage refers the older types of this sort to the genus Coniopteris Bron- gniart, and the later ones to this genus Onychtopsis. It is quite possible that the modern genus Thyrsopteris was a prominent Jurassic and older Cretaceous type, there being many parallel cases, as, for example, the gymnospermous genus Ginkgo. Some of the evidence is at least suffi- cient to prove that forms named Thyrsopteris are referable to the family Cyatheace, so that in considering the Potomac forms we have to decide whether the fact that the Jurassic forms like Thyrsopteris Maakiana and Thyrsopteris Murrayana of Heer are members of the Cyatheacee shall be given greater or less weight than the fact that the same type of sterile frond very abundant in the Lower Cretaceous from England to Japan has fertile pinnules like those of the genus Onychium of the Polypo- diacee. It is true that only sterile pinnules are known from the Potomac deposits, but the fertile parts have been found associated, and in organic connection with these identical sterile pinnules in California, Japan, England, Belgium (?), Bohemia, and Portugal. The writer prefers to believe that the latter evidence is entitled to the greater weight. The modern genus Onychiwm has several widely distributed, chiefly tropical, species of Japan, China, India, Persia, Abyssinia, and the East and West Indies. In this connection attention should be called to the- fertile specimens from Fredericksburg described as Aspleniopteris pin- nattfida, since this type which is referred to the Aspleniex is very similar to the fertile pinne of a specimen of Onychiopsis Gepperti from Japan, kindly communicated by Professor Yokoyama. MaryYLaND GEOLOGICAL SURVEY 273 ONYCHIOPSIS LATILOB} (Fontaine) Plate XXXIII, Figs. 1, 2 Sphenopteris latiloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 90, pl. xxxv, figs. 3-5; pl. xxxvi, figs. 4-9; pl. xxxvii, fig. 1. Thyrsopteris brevipennis Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 124, pl. xxxiv, fig. 3; pl. xxxvi, fig. 2; pl. xxxvii, figs. 3, 9; pl. xxxviii, fig. 1; pl. xli, fig. 4. Thyrsopteris divaricata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 125; pl. xxxvii, figs. 5-8; pl. clxx, fig. 1. Thyrsopteris crenata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 127, pl. xxxix, figs. 1, 2. Thyrsopteris brevipennis Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 662, pl. clxii, fig. 1a. Sphenopteris latiloba Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 281, 479, 491, 511, 534, 557. Thyrsopteris divaricata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 504, 511, 517, 521. Onychiopsis latiloba Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 332. Description—Frond large tripinnate; principal rachis very stout, sometimes winged. Leaf-substance thin but coriaceous. Primary pinne opposite or subopposite with a stout, rigid rachis, which is often some- what flexuous; ultimate pinne remotely placed, very short, decurrent, passing towards the summit of the principal pinna or of the frond through lobed pinnules into entire ones. Pinnules somewhat remotely placed, cuneate at base, those in the lower part of the frond cut more or less deeply into oblong acute to obtuse lobes, passing towards the tips of the ultimate pinne into lobed pinnules like those of the upper part of the frond, and at the tips into ovate or oblong lobes and teeth. In the upper part of the frond they are elliptical, three lobed, or entire.. All the pinnules and segments are broad. The ultimate pinne and the pinnules of the lower part of the frond usually terminate in three lobed segments or in broad, elliptical pinnules. The veins are copiously branched, diverging flabellately into the lobes and teeth, and are very distinct and strong, although not coarse. This is a fine, large species, probably arborescent, and quite distinct from the other species of Onychiopsis. It is common throughout the Potomac but rather less abundant in the Patapsco formation than in the older beds. It has been recorded from the Lakota formation in the 274 SYSTEMATIC PALEONTOLOGY - Black Hills area and from the Kootanie formation in both Montana and British Columbia. There is some variation exhibited by the various forms referred by the writer to this species, and some of the smaller ultimate pinne.are readily confused with other species of Onychiopsis. The specimen figured is characteristic, and well shows the distinctness of this type when represented by reasonably complete material. Occurrence-—Patuxent Formation. Fredericksburg, Dutch Gap, Telegraph Station (Lorton), Virginia; New Reservoir (?), District of Columbia. ArcnpEL Formation. Bewley Estate (?), Bay View (com- mon), Maryland; Langdon, District of Columbia. Patapsco Forma- TION. Deep Bottom, Mt. Vernon, Hell Hole (?), Chinkapin Hollow (?), Virginia; Federal Hill (Baltimore), Maryland. Collections. —U. S. National Museum, Johns Hopkins University. Goucher College. ONYCHIOPSIS PSILoTOIDES (Stokes and Webb) Ward Plate XXXV; Plate XXXVI, Figs. 7-9 Hymenopteris psilotoides Stokes and Webb, 1824, Trans. Geol. Soc., Lon- don, 2d ser., vol. i, p. 424, pl. xlvi, fig. 7; pl. xlvii, fig. 2. Hymenopteris psilotoides Sternberg, 1825, Fl. Vorwelt, Tentamen, p. xxii. Sphenopteris Mantelli Brongniart, 1827, in Mantell, Illus. of the Geol. of Sussex [revised ed.], p. 55, pl. i, figs. 8a, b; pl. iii, figs. 6, 7; pl. iii*, fig. 2. Sphenopteris Mantelli Brongniart, 1828, Prodrome, p. 50; Hist. végét. foss., 1828, p. 170, pl. xlv, figs. 3-7. Sphenopteris Mantelli Mantell, 1833, Geol. S. E. England, p. 241.. Sphenopteris Mantelli Sternberg, 1833, Fl. Vorwelt, vol. ii, pts. v, vi, p. 56. Cheilanthites Mantelli Goeppert, 1836, Syst. Fil. Foss., p. 231. Cheilanthites denticulatus F. A. Roemer, 1839 [non (Brongn.) Gépp.], Verst. d. Norddeutsch. Oolithen-Gebirges,; Nachtrag, p. 9, pl. xvii, fig. la. Confervites fissus Dunker, 1844, Program d. héheren Gewerbschule in Cassel, 1843-1844, p. 5. Sphenopteris Mantelli Unger, 1845, Syn. Plant. Foss., p. 59. Confervites fissus Dunker, 1846, Monogr. d. Norddeutsch. Wealdenbildung, p. 1, pl. i, fig. 1. Sphenopteris Rémeri Dunker, Ibid., p. 8, pl. i, figs. 3, 4, 4a, 5. Sphenopteris tenera Dunker, Ibdid., p. 3. pl. viii, fig. 5. Sphenopteris Mantelli Dunker, 1846, Monogr. d. Norddeutsch. Wealdenbild- ung, p. 2, pl. i, fig. 4a. Sphenopteris Mantelli Bronn, 1848, Index Pal., p. 1169. MaryLanp GEOLOGICAL SURVEY 275 Sphenopteris Mantelli Unger, 1850, Gen. et Sp., 1850, p. 108. Sphenopteris Mantelli Bronn, 1852, Leth. geogn., vol. ii, 1851-52, p. 49, pl. xxviii, figs. 4a, b. Sphenopteris Mantelli, Ettingshausen, 1852, Abh. k. k. geol. Reichs, p. 14, pl. iv, figs. 3, 4. Microlepia Mantelli Ettingshausen, 1865, Farnkrauter der Jetztwelt, p. 216. Sphenopteris antipodum Tate, 1867, Quart. Jour. Geol. Soc., London, vol. xxiii, p. 146, pl. vi, fig. 3. Sphenopteris Mantelli Schimper, 1869, Pal. Végét., tome i, p. 393; Ibid., vol. iii, 1874, p. 469. : Sphenopteris Mantelli Schenk, 1871, Paleontographica, Band xix, p. 6 (208), pl. ii, figs. 1-8; pl. iv, fig. 6 (?); Ibid., vol. xxiii, 1875, p. 158, pl. xxviii, fig. 12. Sphenopteris Gepperti Schenk, 1871 (pars), Paleont., Band xix, p. 7, (209), pl. iv, fig. 3 (non figs. 2, 4, 5 or pl. ix, fig. 2). Sphenopteris Mantelli Heer, 1881, Cont. Fl. Foss. Port., p. 12, pl. xi, figs. 1-5; pl. xii, figs. 2b, 2bb. Aspidium Oerstedi Lesquereux, 1888, Proc. U. S. Nat. Mus., vol. xi, p. 32 in part, quoad Cat. U. S. Nat. Mus., No. 2434, Lesquereux’s Nos. 913- 915a. Sphenopteris Mantelli Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 91, pl. i, figs. 1, 2. Sphenopteris Mantelli Nathorst, 1890, Denks. k. Akad. Wiss., Wien, Band Ivii, p. 55. Thyrsopteris insignis Fontaine, 1890, Monogr. U. S. Geol. Survey, vol. xv, 1889, p. 127, pl. xxxix, fig. 4; pl. xl, fig. 1; pl. xli, fig. 6; pl. xlii, figs. 1, 2, 4; pl. xliii, figs. 1, 3. Thyrsopteris insignis angustipennis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 128, pl. xlii, fig. 3; pl. xliii, fig. 2. Thyrsopteris angustifolia Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 181, pl. xliv, fig. 4; pl. xlv, fig. 3; pl. xlviii, fig. 2; pl. xlix, figs. 3, 4; pl. lv, fig. 2; pl. lviii, fig. 8. Thyrsopteris microphylla Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 131, pl. xlv, figs. 1, 2, 4, 5. Thyrsopteris rarinervis Fontaine, 1890, Mongr. U. S. Geol. Survey, vol. xv, 1889, p. 123, pl. xxvi, figs. 6, 7; pl. xliii, figs. 4-6; pl. xliv, figs. 1, 2, 5; pl. xlix, fig. 2; pl. clxix, figs. 6, 7. Sphenopteris Mantelli Engelhardt, 1891, Kreidepflanzen von Niederschéna, Abh. Isis Dresden, p. 79. Sphenopteris Mantelli Saporta, 1891, Compt. rendus, tome cxiii, p. 250. Sphenopteris Mantelli Saporta, 1894, Fl. Foss. Portugal, pp. 72, 124, 157, pl. xv, figs. 8-12; pl. xviii, fig. 5; pl. xxiii, figs. 1, 2, 8; pl. xxviii, fig. 2; pl. xxix, fig. 1; pl. xxx, figs. 9, 10; pl. xxxi, figs. 1, 2. Onychiopsis Manteili Seward, 1894, Wealden Flora, pt. i, p. 41, figs. 4, 5 on p. 50, fig. 6 on p. 52, pl, ii, fig. 1, pl. ili, figs. 1-4.. Thursopteris dentifolia Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 660, pl. clxi, figs. 6-9. 276 SYSTEMATIC PALEONTOLOGY Onychiopsis Mantelli Seward, 1900, Fl. Wealdienne de Bernissart, mém. Musée Roy. d@’hist. nat. de Belgique, Année 1900, p. 15, pl. i, figs. 17-19; pl. ii, figs. 20, 21. Onychiopsis Mantelli Seward, 1903, Ann. S. Afr. Mus., vol. iv, p. 5, pl. i; pl. v, fig. 1. Thyrsopteris insignis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xviii, 1905, p. 521. Thyrsopteris angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 516. Thyrsopteris rarinervis Fontaine, 1906, in Ward, Mongr. U. S. Geol. Survey, vol. xlviii, pp. 225, 484, 491, 514, 517, 518, 519, 521, 528, 548, 558, pl. Ixv, figs. 2-4; pl. exiii, figs. 2, 3. Onychiopsis psilotoides Ward, 1906, in Fontaine, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 155 (name only). Onychiopsis psilotoides Fontaine, 1906, Ibid., pp. 506, 518, 528, pl. exi, fig. 4; pl. exiii, fig. 1. Onychiopsis Mantelli Richter, 1906, Beitr. z. Fl. der unteren Kreide Qued- linburgs, Teil. 1, p. 6. Onychiopsis psilotoides Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. xix, 1908, p. 380. Onychiopsis psilotoides Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 330. Description —* 8. foliis bipinnatifidis, pinnis approximatis virgatis fastigiatis, pinnulis obliquis, omnibus integris uninerviis, angustis, cune- atis, apice oblique truncatis et subemarginatis; parte exteriori longius producta.”—Brongniart, 1828. “Frond tripinnate, ovate lanceolate, rachis winged and prominent; pinne lanceolate, alternate, approximate, given off from the main rachis at an acute angle. Pinnules alternate, narrow, lanceolate acuminate, uninerved, of nervation type- Cceopteridis (Luerssen, in Rabenhorst’s Krypt. FL, vol. iii, p. 11) ; the larger ones serrate and gradually passing into pinne with narrow ultimate segment. Fructification in the form of sessile or shortly stalked linear ovate segments with rugose surfaces, and terminating usually in a very short awn-like apical prolongation.” — Seward, 189+. The foregoing are respectively the first and last diagnoses of this species and will suffice for the Maryland forms, with the exception that fertile specimens are altogether unknown thus far in this region. This species is not nearly so common in the Potomac as is Onychiopsis Geppertt, although it appears to have a wider range and to be more common abroad. It occurs at all horizons in the Potomac, however, a vertical range which is paralleled by its range from the Valanginian MARYLAND GEOLOGICAL SURVEY QU7 through the Barremian into the Albian of Portugal. Elsewhere in Europe it has been found in the Wealden of England, Belgium, and Germany, the Neocomian near Quedlinburg, Saxony, and in the Barremian of Austria. Forms which are identical, according to Seward (Joc. cit.) are found in the Uintenhage series of South Africa, while Nathorst has de- scribed similar remains from the Jurassic-Cretaceous boundary in Spitz- bergen as Sphenopteris sp. A.’ In this country outside of the Potomac it is found in the Kootanie at Great Falls, Montana; in the Shasta beds of California, and in the Lakota formation of the Black Hills. The forms identified as this species from the supposed Jurassic near Cape Lisburne, Alaska, have been shown by Knowlton to be forms of Dicksonia. Saporta, in his treatment of the Portuguese forms, leaves them‘in the genus Sphenopteris, but thinks that they are more closely related to certain modern species of Davallia than to Onychium. His’ figures, however, do not bring this out with any degree of certainty. Professor Seward, in discussing specimens from South Africa (ioc. cit.), unites with this species the Japanese Jurassic and Cretaceous forms des- ignated as Thyrsopteris elongata Geyler and Onychiopsis elongata Yoko- yama. The reason for the proposed change is the discovery in the Eng- lish Wealden of more extensive material which showed the psilotoides type of pinnule distad and the elongata type of pinnule proximad. It is quite possible that the remains from the English Wealden are all of one species, but it certainly does not follow that the synonymy follows such a disposition. The American remains identified with the elongata type show that the forms with broader segments are not portions of fronds with the distal basal characters of psilotoides, although there is in most ferns more or less diminution in size upward. Through the kindness of Prof. Yokoyama the writer has received specimens of elongata from the Jurassic of Kaga, Japan, aud these are certainly specifically distinct, especially in the fertile pinne, from the English forms of psilotoides. They are therefore included in the present 1Nathorst, Kgl. Svenska Vetens.-Akad., Handl., Band xxx, No. 1, 1897, p. 49, pl. ii, fig. 14. 278 ’ SysteMATIC PALEONTOLOGY | discussion odes Ongena Geppertt, which’ is relaed as & distinet species. Occurrence —Paruxent Formation. Fredericksburg, Dutch Gap; Trents Reach, near Potomac Run, Virginia ; New Reservoir, 16th Street, District of Columbia. ARUNDEL FoRMATION. Langdon, District of Col- umbia ; Bay ‘View, Maryland. Patapsco Formation. Federal Hill (Baltimore), Stump Neck, near Wellhams, Maryland; near Brooke, Widewater, Hell Hole, Virginia. Collection —U. 8. National Museum. ONYCHIOPSIS BREVIFOLIA (Fontaine) Berry Plate XXXIV, Figs. 1, 2 Thyrsopteris brevifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 121, pl. xxiv, figs. 5, 10. Thyrsopteris dentata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 121, pl. xxiv, figs. 4, 6, 7, 9; pl. xxv, figs. 1, 2. Thyrsopteris pachyphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 185, pl. 1, fig. 3. Thyrsopteris nana Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 141, pl. Ivi, figs. 4, 8. Thyrsopteris heterophylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 142, pl. lviii, fig. 3. Thyrsopteris sphenopteroides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 148, pl. lviii, fig. 6. Thyrsopteris squarrosa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 148, pl. lix, fig. 3. Thyrsopteris retusa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 144, pl. lix, fig. 10. Tayrsopteris brevifolia Fontaine, 1899, in. Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 660, pl. clxi, figs. 10-15. ‘Onychiopsis brevifolia Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 329. Description.—Frond small, bipinnate or tripinnate. Rachises rather slender, often winged. Pinne alternate to subopposite, relatively long and narrow, divided below, pinnatifid distad. Pinnules much narrowed at the base, decurrent, obliquely toothed or divided, the extent depending upon their position on the frond, triangular ovate to lanceolate in out- line. Veins somewhat flabellate, once or twice forked or simple. Tex- ture coriaceous. This species is not common in the Potomac and is confined to the basal beds in the Virginia area, although it has also been reported from MaryYLanpb ‘GroLocgicaL SuRVEY 279 the Lakota formation in the Black Hills region and from the’ Kootanie formation of Montana. It is represented in the Virginia area by quite a large number of mostly fragmentary specimens showing ‘slight varia- tions in the character of the pinnule-lobes or teeth which were made the basis for distinguishing eight species by Professor Fontaine. It is pos- sible that more than one type is included ‘in the species as defined by the writer, the nature of the material rendering certainty out of the question, but if the test of the validity of a species be the possibility of its being recognized a second time by either the original author or other students, it must be admitted that, these eight so-called species are not ‘good species. Onychiopsis brevifolia differs from Onychiopsis Gepperti and psilo- toides principally in the smaller fronds, less robust pinnules, which are also less ascending, and in the much less elongate character of the pinnz and especially the pinnules. It is a much smaller and less robust form than Onychiopsis latiloba, from which it is readily distinguished, but approaches somewhat close to Onychiopsis nervosa. The latter species is on the whole a larger form with less elongate and more tri- angular pinne, and the pinnules have more entire margins, the lobes or teeth being rounded and not angular. The veins are also more numerous. Occurrence-—Patuxenr ForMArIon. Fredericksburg, Dutch Gap, Potomac Run, Telegraph Station (Lorton), Virginia. Collection —U. 8. National Museum. ONYCHIOPSIS NERVOSA (Fontaine) Berry Plate XXXVI, Figs. 1-6 Thyrsopteris nervosa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 122, pl. xxv, figs. 4, 5, 16; pl. xxxvii, figs. 2, 4; pl. xxxix, fig. 5; pl. xl, fig. 6. Thyrsopteris Meekiana Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 125, pl. Xxxviii, figs. 2-4, 8; pl. 1, figs. 7, 8; pl. li, fig. 3. Thyrsopteris crassinervis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 130, pl. xli, figs. 1-3. Thyrsopteris pecopteroides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 135, pl. li, fig. 1. Thyrsopteris heteroloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p.-139, pl. liii, fig. 4. 2 280 SYSTEMATIC PALEONTOLOGY Thyrsopteris obtusiloba Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 143, pl. lviii, figs. 7, 10. Thyrsopteris crassinervis Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 658, pl. clxi, figs. 3, 4. Thyrsoptleris pecopteroides Fontaine, 1899, Ibid., p. 661, pl. clxi, figs. 16- 19. Adiantites parvifolius Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 558, pl. cxvii, fig. 4. Thyrsopteris nervosa Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 511, 517, 519, 521, 528, 548, 571. Thyrsopteris Meekiana Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 519, 565; pl. cxix, fig. 1. Thyrsopteris crassinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 513, 528, pl. cxii, figs. 5, 6. Onychiopsis nervosa Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 327. Description.—Frond bipinnate or tripinnate. Principal rachis medi- umly stout, somewhat flexuous, sometimes winged in the upper part. Pinne alternate or subopposite, ovate to ovate-lanceolate in outline, be- coming entire apically, the pinnules passing into dentate teeth while the ultimate pinnae become dentate pinnules. This character renders distal fragments quite different in appearance from the normal form of this species, and quite like Cladophlebis. In some individuals the pinne lower down on the frond assume this form, constituting the supposed species Thyrsopteris crassinervis of Professor Fontaine and well shown in the specimens figured from Chinkapin Hollow and near Glymont. Every gradation is shown, however, between this type and the usual type of pinne made up of alternate, very oblique, decurrent pinnules, usually rather deeply cut into subrhombic basal lobes which become ovate or elliptical lobes, and finally teeth in passing distad. Base contracted, subpetiolate. Veins numerous and slender, but very distinct, branching obliquely, flabellate, repeatedly forked, subparallel. Texture coriaceous. While the fragments of the fronds of this species are all small the plant which bore them must have been of quite considerable dimensions. Representative material is readily distinguished from the other species of Onychiopsis recognized, but small fragments are liable to confusion with Onychiopsis brevifolia, in fact Professor Fontaine founded no less than six nominal species upon such fragments, all of which are believed by the writer to represent slight variations of a single species. MarRYLAND GEOLOGICAL SURVEY 281 It is widely distributed throughout the Potomac Group, but not com- mon at any outcrop. Outside this area it has been reported from the Lakota formation of the Black Hills. Practically identical remains from the Lower Cretaceous of Portugal are described by Saporta as various species of Sphenopteris. Occurrence—PaTuxENT FoRMATION. Fredericksburg, Dutch Gap, Potomac Run, Virginia; New Reservoir, Ivy City, District of Columbia; Springfield, Maryland. ArunprL Formation. Langdon (frequent), District of Columbia. Patarsco Formation. Chinkapin Hollow, Vir- ginia; Ft. Foote, near Glymont, Vinegar Hill (?), Federal Hill (Balti- more), Maryland. Collections—U. S. National Museum, Maryland Academy of Science, Goucher College. ONYCHIOPSIS G@PPERTI (Schenk) Berry Plate XXXIV, Tigs. 3, 4 Sphenopteris Gepperti Schenk, 1871 (pars), Paleontographica, Band xix, 1871, p. 7 (209), pl. iv, fig. 2 (mon figs. 3-5 or pl. ix, fig. 2). Thyrsopteris elongata Geyler, 1877, Paleontographica, Band xxiv, p. 221. Thyrsopteris elongata Schenk, 1883, in Richthofen’s China, Band iv, p. 263, pl. liv, fig. 1. Dicksonia elongata Yokoyama, 1886, Bull. Geol. Soc., Japan, vol. i, No. 1, p. 5. Onychiopsis elongata Yokoyama, 1890, Jour. Coll. Sci., Japan, vol. iii, p. 27, pl. ii, figs. 1-3; pl. iii, fig. 6d; pl. xii, figs. 9, 10. Onychiopsis elongata Nathorst, 1890, Denks, k. Akad. Wiss., Wien, Band lvii, pp. 44, 48, 50, 51, 52, 58, 54, pl. v, fig. 8; pl. vi, fig. 5. Thyrsopteris alata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 124, pl. xxxvi, fig. 3. J Thyrsopteris Meekiana angustiloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 126, pl. xxxviii, figs. 5-7, 9; pl. xliii, fig. 8; pl. xliv, fig. 3; pl. xlvii, fig. 4; pl. xlviii, fig. 1; pl. liv, figs. 2, 11; pl. Iv, fig. 1; pl. lvi, figs. 1, 3. Thyrsopteris angustiloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 134, pl. xlviii, figs. 3-5; pl. lv, fig. 3. Thyrsopteris densifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 129, pl. xxxix, fig. 3; pl. xl, figs. 2-5; pl. li, fig. 5. Thyrsopteris decurrens Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 130, pl. xliii, fig. 7; pl. xlvi, figs. 2, 4; pl. xlix, figs. 5-7. Thyrsopteris virginica Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 120, pl. xxiv, fig. 1. 282 SYSTEMATIC PALEONTOLOGY Thyrsopteris pachyrachis Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol.. xv, 1889, p. 132, pl. xlvi, figs. 3,.5; pl. xlvii, figs. 1, 2; pl. xlix, fig. 1. Thyrsopteris elliptica Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 138, pl. xxiv, fig. 3; pl. xlvi, fig. 1; pl. 1, figs. 6, 9; pl. li, figs. 4, 6, 7; pl. liv, fig. 6; pl. lv, fig. 4; pl. lvi, figs. 6, 7; pl. lvii, fig. 6; pl. lviii, fig. 2. Thyrsopteris distans Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 134, pl. xlvii, fig. 3; pl. liv, fig. 8. Thyrsopteris pinnatifida Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 186, pl. li, fig. 2; pl. liv, figs. 4, 5, 7; pl. Ivii, fig. 7. Thyrsopteris varians Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 137, pl. lii, figs. 2-4; pl. liii, figs. 1-3; pl. liv, fig. 10; pl. Ivii, fig. 2. Thyrsopteris rhombifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 188, pl. lii, fig. 5; pl. liv, fig..1. Thyrsopteris bella Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 139, pl. liii, fig. 5; pl. lv, figs. 6, 7; pl. lvi, figs. 2, 5; pl. lvii, figs. 1, 5; pl. Iviii, fig. 4. Thyrsopteris microloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 140, pl. Ivii, fig. 4. : Thyrsopteris microloba alata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 140, pl. lv, fig. 5; pl. lviii, fig. 1. Thyrsopteris inequipinnata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 142, pl. lvii, figs. 3, 8. Thyrsopteris rhombiloba Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 144, pl. lix, fig. 7; pl. Ix, fig. 8. Sphenopteris Gepperti Saporta, 1894, Fl. Foss. Portugal, pp. 71, 123, 159, pl. xviii, fig. 6; pl. xxiii, fig. 8; pl. xxix, fig. 6. (?) Onychiopsis elongata Seward, 1894, Wealden F1.,, pt. i, p. 55, pl. ii, fig. 2. Thyrsopteris elliptica Fontaine, 1898, in Ward, 18th Ann. Rept. U. S. Geol. Survey, pt. iii, p. 482. Thyrsopteris elliptica Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 659, pl. clxi, fig. 5.° Thyrsopteris pinnatifida Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 658, pl. clxi, figs. 1, 2. Thyrsopteris Meekiana angustiloba Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 557. Thyrsopteris densifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 484, 511, 517. Thyrsopteris decurrens Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 484, 491, 511, 525, pl. exi, fig. 11. Thyrsopteris pachyrachis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 487, 538, 557. Thyrsopteris elliptica Fontaine, 1906, in Ward, Mongr. U. 8S. Geol. Survey, vol. xlviii, 1905, pp. 290, 484, 514, 517, 528, 557, pl. lxxi, figs. 12, 13. Thyrsopteris pinnatifida Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 511. Thyrsopteris bella Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 491, 511. MaryYLAND GEOLOGICAL SURVEY 283 Thyrsopteris microloba alata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 281. Thyrsopteris elliptica Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, . 110. : Gore Goepperti Berry, 1911, Proc. a S. Natl. Mus., vol. xli, p. 325. Description —* Frond slender, bi-tripinnated; sterile pinne alternate or rarely opposite, elongated, their length rapidly increasing towards the lower part of the frond; pinnules alternate, acutely directed forward, lanceolate or linearly-lanceolate, entire or lobed, or even pinnately parted; lobes or partitions acute at apex and acutely directed forward just like the pinnules themselves. Venation obsolete, secondary veins simple, each going into a lobe. Fertile pinnules elongated, with a linear terminal sorus on both sides of the midrib.”—Yokoyama, 1890. A very large number of Fontaine’s species of Thyrsopteris fall within the limits of this species. There is, to be sure, some variation in the relative length and breadth of the pinnules, but the material shows every gradation of form, it being possible to select individual pinnules from a single frond fragment which exemplify several of the supposed types. On the whole, the pinnules are somewhat more robust than in the foreign material, and the rachis is inclined to be stouter and may or may not be winged. This is an exceedingly common form in the Potomac from the oldest to the youngest. stratum, and it has also been recorded from the Kootanie of Montana at Great Falls, Geyser, etc., and possibly some of Dawson’s identifications of Asplenium Dicksonianum Heer from the Canadian Kootanie should also be referred to this species. It also occurs in the Lakota formation of the Black Hills. Abroad it is rather rare in the English and German Wealden, but its geological distribution in the Lower Cretaceous of Portugal rivals. that of eastern America, since. it comprises considerable material from the Valanginian, Barremian, and Albian terranes. With regard to its occurrence in the Neocomian of eastern Asia, Yokoyama writes (loc. cit.) that it is the “chief and char- acteristic fossil of the Japanese flora, being found in all of the fossil localities.” That this species or Onychiopsis psilotoides, or, both, occur in the Kome beds of western Greenland seems probable, and several of Heer’s 284 SYSTEMATIC PALEONTOLOGY species of Asplenium, notably Asplenium Dicksonianum Heer,’ suggest themselves for comparison. While the writer has not ventured to include any of them in the synonymy of this species, they certainly are very close to this type in appearance. The English forms are questioned in the synonymy, since Prof. Seward * considers the Wealden material iden- tical with that of Onychiopsis psilotoides. This may be true of the English material, but it cannot apply to that from America and Asia, as the writer has shown under the discussion of Onychiopsis psilotoides. Occurrence.—PaTuxEntT Formation. Fredericksburg, Trents Reach, Cockpit Point, Dutch Gap, near Potomac Run, Colchester Road (Pohick Creek ?), Virginia; New Reservoir, Ivy City, District of Columbia. ARUNDEL ForMation., Langdon, District of Columbia; Arlington, Mary- land. Patapsco Formation. Federal Hill (Baltimore), Ft. Foote, Overlook Inn, Vinegar Hill, Maryland; near Brooke, White House Bluff, Mt. Vernon, Chinkapin Hollow, Virginia. Collections.—U. 8. National Museum, Goucher College. Family HYDROPTERACEAE Genus SAGENOPTERIS Presl [In Sternberg, Fl. Vorwelt, Bd. ii, 1838, p. 164] This genus was founded by Presl in 1838 upon material from the Rhetic beds of Strahlendorf, near Bamberg, which he named Sagenop- teris rhoifolia, although admitting that it was identical with that de- : scribed two years earlier by Sternberg as Acrostichites inequilateralis. As it is now generally admitted that the Filicites Nilsoniana of Bron- gniart, described in 1825 from the Rheetic beds of Schonen, is the same species, the proper specific name of the type becomes Sagenopteris Nil- soniana, as pointed out by Ward in 1906. Presl characterized the genus as follows: “ Frons pinnata, pinnis ternatim rarius binatim compositis. Vene tenuissime, ramosissime, ‘Heer, Fl. Foss. Arct., Band iii, Ab. 2, 1874, p. 31, pl. i, figs. 1-5; ibid., Band vi, Ab. 2,'1882, pp. 3, 33, pl. ii, fig. 2; pl. xxxii, figs. 1:8. ? Seward, Ann. S. Afr. Mus., vol. iv, 1903, p. 7. MARYLAND GEOLOGICAL SURVEY 285 eequales, in maculas irregulariter hexagonoideas elongatas confluentes. Coste crass usque ad apicem pinnularum excurrentes.” Schimper redescribed the genus in 1869,* adding the following epider- mal characters: “ Epidermide superiore inequaliter rectangula, inferiore polygono-areolata stomatibusque pertusa.” "He concluded from the latter fact that Sagenopteris was without representatives in the modern flora, and that it could not be related to the modern Marsilea, which it re- sembled, and which was thought to Jack stomata on the lower surface of the pinne. Nathorst, one of the strongest supporters of this latter rela- tionship, points out that stomata do occur in this position in Marsilea, and that the abundant fruits which occur in the Rhetic beds near Palsjo, - associated with Sagenopteris undulata Nathorst, and which cannot be referred to the conifers or cycads, are, in the absence of angiosperms, the sporocarps of Sagenopteris, a conclusion independently arrived at by Heer. Similar sporocarps, if they are sporocarps, are described by Zigno from the Oolite of Italy. Although Solms-Laubach is inclined to doubt the validity of Nathorst’s argument, and Seward recently * reiterates his belief that Sagenopteris is a true fern and not a Rhizocarp, most authors* place the genus among the Hydropteracee, a view to which Schimper subscribes in Zittel’s Handbuch. Attention should be called in this connection to a specimen figured by Fontaine from near Potomac Run, Virginia, purporting to show the remains of fructification characters in the form of a series of dots which, according to this author, would place the specimen “in the Dictyopteris group of Polypodium.” The characters indicated are not visible on this particular specimen at the present time and no importance is attached to them by the writer.* 1 Schimper, Pal. Végét., tome i, 1869, p. 640. 2 Jurassic FL, pt. ii, 1904, p. 938. Since this was written vol. ii of Seward’s Fossil Plants has been received. In this work the probable relationship between Sagenopteris and Marsilea is admitted. 2 Nathorst, Heer, Schimper, Schenk, Saporta, Potonié, Zeiller, etc. 4Salfeld, in a recent discussion of the Jurassic plants of northern Germany (Paleont., Band ivi, 1909, p. 17), states that he found fructifications on the pinnules of Sagenopteris Nilsoniana Brongniart, but he brings forward no evidence to support his statement. ‘ 286 _ Systematic PALEONTOLOGY Sagenopteris may be defined in the light of our present knowledge as follows: Stipe long and rather stout, bearing apically palmately ar- ranged pinne which are usually four in number. Pinne variable in out- line, even on the same stipe, asymmetrical, linear-lanceolate to ovate. Venation reticulate, the. meshes more or less elongate. Basally, a stout midrib is present which rapidly becomes attenuated and disappears through the anastomosing branches which it gives off. Fructification in the form of oval or spherical bodies resembling sporocarps (?). Remains which have been referred to Sagenopteris are described by Feistmantel from the late Paleozoic, but these are now regarded as be- longing to Glossopteris. Undoubted specimens of Sagenopteris appear in the Keuper, and the genus is prominent in Rhetic and Liassic floras, continuing without perceptible abatement through the balance of the Jurassic. There are seven or eight species in the Lower Cretaceous, mostly American, although Sagenopteris Mantelli is also rather wide- spread in Europe. There are three species in the Potomac Group, one of which also occurs in the Shasta of California and the Lower Cre- taceous of the Queen Charlotte Islands. In the Upper Cretaceous a single species is recorded from the Cenomanian of Bohemia, and this reappears according to Hollick, in the Cretaceous of Chappaquidick Island, Massachusetts. A true Marsilea also occurs at this horizon, and from an earlier horizon Schenk* describes Marsilidium ‘speciosum. SAGENOPTERIS LATIFOLTA Fontaine Sagenopteris latifolia Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 148, pl. xxvii, fig. 10. Description“ Frond unknown; pinnules apparently subquadrilat- eral, narrowed gradually to the base and rapidly to the summit; mid- nerve in the lower part of the pinnule strong, in the upper part dis- solving into’ branches ; lateral nerves going off very obliquely, branching near the midrib, turning outward, and then by repeated branching and > Hollick, Bull. N. Y. Bot. Gard., vol. iii, 1904, p. 409, pl. Ixxi, figs. 1-3. ? Schenk, Paleont., Band xix, 1871, p. 225 (23), pl. xxvi (v), figs. 3, 3a. MarYLAND GEOLOGICAL SURVEY 287 anastomosis forming long, rather regular, elliptical to rhombic meshes, which fill the lamina.”—Fontaine, 1890. This species was based upon two very fragmentary specimens, of which the more complete was figured. It does not differ appreciably from a number of the broader Jurassic species, nor does it offer any very con- elusive differences from the Wealden species Sagenopteris Mantelli (Dunker) Schenk which Fontaine records from the Shasta beds of the west coast, and with which the Potomac species may be identical. Occurrence.—-PATUXENT Formation. Near Telegraph Station (Lor- ton), Virginia. Collection.—U. S. National Museum. SAGENOPTERIS ELLIPTICA Fontaine Sagenopteris elliptica Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 149, pl. xxvii, figs. 9, 11-17. Chiropteris spatulata Newberry, 1891, Amer. Jour. Sci. (iii), vol. xli, p. 199. pl. xiv, figs. 1, 2. Sagenopteris sp., Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc. Amer., vol. v, p. 450. Sagenopteris sp., Fontaine, 1896, in Stanton, Bull, U. S. Geol. Survey, No. 183, p. 15. . Sagenopteris elliptica Penhallow, 1902, Trans. Roy. Soc. Can. (ii), vol. iv, sec. iv, p. 41. Sagenopteris elliptica Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 236, pl. Ixv, figs. 39, 40. Sagenopteris sp., Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 238, pl. lxv, fig. 46. Chiropteris spatulata Knowlton, 1907, Smith. Misc. Coll., vol. 1, pt. i, p. 114. Description.—Stipe stout, apparently crowned with five palmately ar- ranged pinne. No pinne have been found attached, but one specimen - shows five lying disposed around the summit of the stipe. If these really were attached as described by Fontaine they may represent simply a variation and not even constitute a specific character, although no five- parted Sagenopteris has been heretofore described. Pinne variable in size, inequilateral, lanceolate to ovate, obtusely pointed above, gradually narrowed below, 3.5em. to 10cm. in length by 0.7 cm. to 3.6cm. in greatest width, the upper or terminal ones being the largest. Midrib 19 288 SYSTEMATIC PALEONTOLOGY broad at the base, disappearing before reaching the apex. Lateral veins branching at a variable acute angle, anastomosing to form irregular meshes which are subrhombic in some specimens and very much elongated Fie. 4.—Restoration of Sagenopteris elliptica about natural size. with few anastomoses in others. Fontaine describes minute elevations between the veins on the lower surface which he thinks indicate polypo- diaceous fructifications. These are said to be distinctly seen only with ‘the aid of a lens, and’ yet they are 0.5 mm. long in the specimen figured MaryLanp GEOLOGICAL SURVEY 289 natural size. The present writer has failed to find any trace of these supposed fructifications. This species is not common in the later Potomac, and the specimens from Federal Hill, Maryland, are not perfect enough to determine with certainty their identity with those from near Potomac Run, Virginia. Penhallow has recorded this same form from the Queen Charlotte Isl- ands, and it is frequent in the Shasta of California. The Kootanie occurrence is based on forms described by Newberry as a species of Chiropteris and differentiated from Sagenopteris, primarily because of the infrequency of anastomosis of the veins and the consequent elonga- tion of the meshes. This is a feature which is also emphasized in some of the eastern specimens, and also in some of those from California, and it seems quite probable that the Kootanie plant is identical with these others. Seward thinks that the American plant may be identical with the European Jurassic species Sagenopteris pauctfolia (Phillips) Ward. Its similarity to Sagenopteris Mantelli (Dunker) Schenk may also be pointed out, the latter usually having the midrib a much less prominent feature than it isin the American plant. In connection with the supposed five pinnules of the present species it is interesting to recall that in Mar- silidium speciosum, a possibly related form, described by Schenk (ep. cit.) from the Wealden of Osterwald, the pinnules are considered to be six in number. Occurrence.—PATUXENT Formation. Near Potomac Run and Kan- keys, Virginia. Patapsco Formation. Federal Hill (Baltimore), Maryland. Collection—U. 8. National Museum. SAGENOPTERIS VIRGINIENSIS Fontaine Sagenopteris virginiensis Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 150, pl. cxxxviii, fig. 13; pl. cxxxix, fig. 1. Description.—“ Frond unknown ; shape of pinnules not seen, probably broadly elliptical or oval; stipe or petiole of pinnules apparently long; midnerve toward the base very strong, dissolving in branches toward the apex; areolation very distinct, formed by lateral nerves which go off 290 SYSTEMATIC PALEONTOLOGY obliquely and curve outwards to meet the margin, forking repeatedly, and anastomosing to form meshes that are irregular in size and shape, being mostly elongate, oblong, or subrhombic.”—Fontaine, 1890. No additional material referable to this species having been discovered, its claim to validity rests upon the foregoing meagre description and the rare fragments figured by Fontaine which might equally well be refer- able to either of the other Potomac species. In fact such a disposition would probably do no violence to the facts. Occurrence-—PatuxENT Formation. Fredericksburg, Virginia. Collection.—U. 8. National Museum. Family MARATTIACEAE (?) Genus TAENIOPTERIS Brongniart [Prodrome, 1828, p. 61] Brongniart gives the following diagnosis of Teniopteris in his Prodrome*: Fronde simple, entiére, étroite, 4 bords paralléles, transversée par une nervure moyenne, forte, é6paisse, qui s’étend jusqu’éa l’extrémete; nervures secondaires presque simples ou bifurquées 4 la base, presque perpendiculaires sur la nervure moyenne. The type was the Jurassic species Teniopteris vittata; which was compared with the existing genera Danea and Angiopteris of the Marat- tiacese. This diagnosis is repeated in Latin without material change in the Histoire.’ In a later’ work the same author institutes various com- parisons with modern ferns, and points out that the genus probably includes forms of diverse botanical affinities. Three groups are recog- nized: (1) Those with simple fronds like Teniopteris vittata, which suggest modern forms of Acrostichum; (2) those with pinnate or bi- pinnate fronds with articulated pinne like 7. Miinsteri, which Brongni- art is positive is a member of the Marattiacese, and (3) those with non- articulate pinnate fronds like T. Bertrandi. 1Prodrome, 1828, p. 61. ? Brongniart Hist. végét. foss., 1831, p. 262. > Brongniart, Tableau, 1849, p., 21. MaryYLanp GroLogicaL SuRVEY 291 The genus has been ably discussed in its Mesozoic aspects by Saporta, Zigno, Schenk, Schimper, Seward, and other authors, the former espe- cially, while following Brongniart’s original characterization of fronds usually simple, considerably extends his diagnosis." Saporta’s diagnosis is quoted in a recent work by Seward” and need not be repeated. The latter author uses the genus in a wide sense following Nathorst in in- cluding under it such other genera as Oleandridium, Angiopteridium, Marattiopsis, Daneopsis, etc., in which the evidence of relationship seems insufficient for the use of names implying affinity with the respective modern genera. His characterization may be quoted with profit: “Frond simple or pinnate, usually lanceolate or linear-lanceolate, apex acute or occasionally obtusely terminated ; a well-marked midrib from which lateral veins are given off either at right angles or more or less obliquely ; these may be unbranched or acutely forked as they pass toward ”* The relation of the simple species to those with pinnate fronds is uncertain, although they may possibly all belong to the same stock. It proves to be an almost impossible task in the absence of any but the best preserved material to distinguish between Teeniopteris-like forms and the remains of such a cycadaceous genus as Nilsonia. The lateral attachment of the lamina in the former and its superior attachment in the latter are characters which are very often obscured in the process of fossilization and the usual segmentation of the leaf margin. the Nilsonia fronds is also a character which is not constant. The genus is abundant in the late Paleozoic, the Paleozoic forms hav- ing been discussed by Zeiller, White, and others, the latter author point- ing out* their probable filiation with the Megalopteris stock, which ex- tends back to the Middle Devonian. Species of Teniopteris are abundant during the Mesozoic, and occasional occurrences are recorded during the Cenozoic. It may be seriously questioned, however, whether the Paleo- zoie and post-Paleozoic Tzeniopterids belong to the same stock. In the Potomac Group several species have been described under the 1Saporta, Pl. Jurass., tome i, 1873, p. 430. 2 Seward, Wealden Flora, pt. i, 1894, p. 122. 3 Seward, Wealden Flora, pt. i, 1894, p. 124. 4 White, Bull. Geol. Soc. Amer., vol. iv, 1893, pp. 119-132. 292 SyYsTEMATIC PALEONTOLOGY genus Angiopteridium, which it has seemed best to refer to Teniopteris in the absence of all traces of fructification and the consequent lack of certainty regarding their taxonomic position. Species also occur in the Shasta beds of California, and probably in the Kootanie of Montana and British Columbia. It is also a common type.in the European Wealden. Regarding the botanical affinity of the various forms of Teniopteris, it seems very probable that the bulk of them are closely related to the Marattiacee, a family with which they are allied by nearly all of the authors mentioned. In fact most authors ally them directly with living genera; thus Schimper’ positively refers the Rhetic species Teniopteris Miinsteri to the modern genus Marattia, a conclusion which it is difficult to dispute after seeing the magnificent fruiting specimens figured by this author. Schenk,’ on the other hand, thinks this species is closest to Angtopteris, while Raciborski, from the study of fruiting specimens from Poland, which he identifies with this same species, is equally sure of the correctness of Schimper’s conclusions. To mention one or two other in- stances, Schenk* is sure that Danwopsis marantacea (Presl) Heer from the Keuper is a true Danea, and it would be equally difficult to point out the differences between the modern species and the forms of Danwa which Zigno describes from the Jurassic of northern Italy.* Zeiller has suggested that Teniopterits fronds grew in tufts from a creeping rhizome as does the modern Scolopendrium. In a measure confirming this suggestion Chapman” has recently furnished grounds for identifying Ehizomopteris Etheridgei Seward from the Jurassic of Australia as the rhizome of one of the abundantly associated species of Teniopteris. Organic connection cannot be made out but these two fos- sils greatly exceed all other plant remains in the deposits, and certain specimens show the basal parts of T@niopteris fronds crushed in various positions along the rhizomes. * Schimper in Zittel’s. Handbuch, 1890, p. 85. 7Schenk, Die foss. Pflanzenreste, 1888, p. 30. >Tdem, p. 35. *Flora fossilis formationis Oolithice, Padova, 1856-1885. 5 Chapman, Records Geol. Surv., Victoria, vol. iii, pt. i, 1909, p. 105. MARYLAND GEOLOGICAL SURVEY 293 T-ANIOPTERIS AURICULATA (Fontaine) Berry Angiopteridium auriculatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 113, pl. vii, figs. 8-11; pl. xxvili, fig. 1. Teniopteris auriculatum Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 634. Description—* Frond pinnate; pinnules thick and leathery, long linear, subacute, remotely placed, free to the base, auriculate at base, attached by the midrib alone; auricles of the bases of the pinnules over- lapping the upper surface more or less; midrib of pinnules rather stout and rigid; lateral nerves often obscurely shown, fasciculate or bifurcate, and towards the tips simply forked. “The plant is rare at each locality, but is most common at Fredericks- burg. It is something like Pteris longipennis Heer,’ but there is no reason to think that it is a Pteris. It also resembles Pecopteris salici- folia® Oldham and Morris. The forms figured in figs. 8, 9, 11 occur at Fredericksburg ; fig. 10 occurs at the locality near Potomac Run. This is different from the others in the great length of the pinnules and in the fasciculate nerves, which are bifurcate, with the branches again forking near their tips. The nerves are obscure on the upper surface of the pinnules. The main rachis is stout and keeled on the under surface, as is shown in fig. 9. On the upper surface the auricles at the base of the pinnules overlap more or less the surface of the main rachis.”—Fontaine, 1890. No new material referable to this species has been collected. Occurrence.—PaTUxXENT Formation. Fredericksburg and Potomac Run, Virginia. Collection —U. S. National Museum. TZ NIOPTERIS NERVOSA (Fontaine) Berry Plate LXXVII, Fig. 1 Angiopteridium nervosum Fontaine, 1890, Mon. U. S. Geological Survey, vol. xv, 1889, p. 114, pl. xxix, fig. 2. Angiopteridium densinerve Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 115, pl. xxix, fig. 4. 1Heer, Foss. Fl. Arct., Band vi, Abth. ii, pl. x, figs. 5-13. 2 Foss. Flora of the Rajmahal series, pl. xxvii, fig. 2. 294 SYSTEMATIC PALEONTOLOGY Angiopteridium pachyphyllum Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 115, pl. xxix, fig. 5. Angiopteridium strictinerve Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 116, pl. xxix, figs. 8, 9 (non Font., in Ward, 1906). Angiopteridium strictinerve latifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 116, pl. xxx, figs. 1, 5. Anomozamites angustifolius Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 167, pl. xxx, fig. 3 (non. fig. 2). Anomozamites virginicus Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 168, pl. xxx, fig. 4; pl. xxxi, fig. 3. Angiopteridium strictinerve latifolium Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 241, pl. lxvi, figs. 8-10. Teniopteris nervosum Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 634. DescriptionHabit unknown, indications in one or two specimens that the frond was pinnate in character. Pinne (or frond) linear-lan- ceolate to elongate-lanceolate. Length unknown, apparently ranging from 10cm. to 30cm. Maximum width 1.2cm. to 5em. Texture cori- aceous. Midrib rather stout and prominent. Lateral veins thin but dis- tinct, especially on the lower surface, more or less closely placed, parallel, curving backward from the midrib, and then straight or slightly curved upward to the margin. Angle of divergence wide, 45° to 90°. Veins either simple or forked, the forking usually near the base, both kinds often shown on a single specimen. This species is based entirely upon very fragmentary material, which served Fontaine for the differentiation of five species of Angiopteridium and two species of Anomozamites. There is absolutely no ground for the reference of any of the material to the genus Anomozamites, and it is all obviously identical. There is some slight variation from specimen to specimen, for example the midrib is somewhat less stout in Angiopteri- dium nervosum and densinerve, as delimited by Fontaine, and the angle of divergence is somewhat more acute in the latter, but these are not char- acters of specific value. If similar recent fronds, such as those of Oleandra, Angiopteris, or Marattia be examined, the size of the midrib, the remoteness or closeness of the lateral veins and their angle of di- vergence will be found to vary through much wider limits, a single frond often exhibiting the extremes in this respect. MARYLAND GEOLOGICAL SURVEY 295 A single specimen from Fredericksburg figured by Fontaine (1890, pl. xxix, fig. 9), and showing apparently the basal portion of three pinnz lying in the same plane and direction, and two of them attached to stout bits of rachis, is the only evidence that the fronds were pinnate and not simple. These may represent aérial stalks, or they may equally well be interpreted as fragments of a rhizome or a rootstock. This species is not common in the Potomac Group, and is confined to the Patuxent formation. Similar remains are described from both the Knoxville and Horsetown beds of the Pacific Coast, and similar frag- mentary specimens are described by Saporta* from the Valanginian of Portugal and referred to Schimper’s genus Oleandridium. In the Euro- pean Wealden there is Oleandridium Beyrichit Schenk’® from Germany and England which Seward refers to Twniopteris, and two other forms of questionable distinctness which the latter author describes from the English beds. Oleandra arctica Heer * from the Kome beds of Green- land may be compared with the Potomac Teniopterids. Newberry ° identifies this species in the Kootanie of Montana, the latter forms at least being probably identical with the Virginia species. Occurrence.—PaTUXENT Formation. Fredericksburg, near Potomac Run; near Telegraph Station (Lorton), Virginia. Collection.—U. 8. National Museum. Genus TEMPSKYA Corda (Beitr. z. Fl. der Vorwelt, 1845, p. 81] This peculiar genus was founded by Corda in 1845, who diagnosed it in the following terms: “Truncus .... Rhachis rotundata, plicata vel alata; cortice crassiuscula, fasciculis vasorum ternatis, majori clauso vel lunulata et supra incurvo, minoribus oppositis lunulatis. Radices minute numerosissime; fasciculo vasorum centrali unico.” +Saporta, Fl. Foss. Portugal, 1894, p. 85, pl. xv, fig. 3; pl, xvi, fig. 18. 2 Schenk, Paleontographica, Bd. xix, 1871, p. 221, pl. xxix, figs. 6, 7. ® Seward, Wealden F1., pt. i, 1894, pp. 127, 128. *Heer, Fl. Foss. Arct., Bd. iii, Ab. ii, 1874, p. 38, pl. xii, figs. 3-11. Newberry, Amer. Jour. Sci. (iii), vol. xli, 1891, p. 201, pl. xiv, fig. 9. 296 SysTteEMATIC PALEONTOLOGY Four species were recognized thus early, of which the exact occurrences were not certainly known except in the case of Tempskya Schimpert, which came from the Wealden of England and Germany and which was described by Stokes and Webb? in 1824 as Endogenites erosa. This was referred to Sternberg’s genus Protopteris by Unger? in 1845. Similar remains had’ previously been referred to Porosus by Cotta (1832) and also to the genus Palmacites of Brongniart by Corda (1845-1846). Schenk * in 1871 with material from the Lower Cretaceous showed that Corda’s view which had been based on fragments, that Tempskya repre- sented the peripheral part of fern trunks with leaf bases and adventive roots, was not entirely accurate. From his more perfect material he concluded that there were several steles of various sizes, the whole im- bedded in parenchyma and probably enclosed in a cortex. According to Schenk the smaller and more numerous steles consist of an axial bundle of scalariform elements surrounded by a sheath of sclerenchyma, while the larger show the fibrovascular elements arranged in a horseshoe- like curve surrounding delicate parenchymatous elements. Subsequently. Hosius and von der Marck* described a species from the lower Senonian of Westphalia and Velenovsky’ lumped a large number of occurrences of Wealden, Cenomanian, and Senonian forms under the new name LTempskya varians. Schenk’s smaller steles are now known to be adventitious roots of the normal fern type, the central radial bundle being diarc according to Seward but hexare according to Solms-Laubach. ‘lhe larger or trne steles are also typically filicinean and were compared by Schenk with those of the Marattiacex. *Stokes and Webb, Trans. Geol. Soc. Lond., 2d series, vol. i, 1824, p. 423, pl. xivi, figs. 1, 2; pl. xlvii, figs. 5a, b. ? Unger, Synopsis Plantarum Fossilium, 1845, p. 107: *Schenk, Paleontographica, Band xix, 1871, p. 259, pl. xlii, fig. 4; pl. xliii (separate p. 57, pl. xxi, fig. 4; pl. xxii). *Hosius and v. d. Marck, Paleont., Band xxvi, 1880, p. 192, pl. xxxix, figs. 161-163. 5 Velenovsky, Farne béhm. Kreidef., 1888, p. 23, pl. v, fig. 5; pl. vi, figs. 1-7. MaryYLAND GrOLOGIOAL SURVEY 297 t They owe this comparison with the latter to a considerable extent to the presence of adventitious roots as in Angiopleris where these roots originate near the top of the stem and grow downward through. the cortical tissue. Again in the late Paleozoic Psaronius stems there are a mass of closely packed roots separated from the true vascular region by a zone of sclerenchyma, the whole enclosed in a true cortex. In the latter some of the steles are cauline and some are common while in Y'empskya they are apparently all common, and Tempskya differs from all other known forms in the singular interlacing course of the steles. ‘heir course has, however, not as yet been made out with certainty. The Potomac material while abundant is poorly preserved and is in- teresting chiefly as the first record of this singular type of fern from North America. Seward * discussed the genus at length in 1894 and followed Feist- mantel (1872) and Solms-Laubach (1891) in regarding Tempskya as a condition of preservation of fern stems rather than as a precise term for a distinct type. There can be no doubt but that the Maryland forms are a distinct type or that they are not generically different from the Wealden forms. They are not portions of fern stems above the stem apex, as Corda suggests, nor basal parts of stems as Stenzel suggests, neither have they lost their vascular cylinder during fossilization, nor are they rhizomes creeping among the felted roots of a Protopteris stem. The Maryland material is abundant and the stems are all nearly circular in cross-sec- tion. While the ‘preservation is too poor for. histological detail it is good enough to show that there never was a distinct central vascular cylinder, despite the fact that both Feistmantel and Velenovsky consider certain specimens of Tempskya as having such a cylinder of the Protopteris type. Unfortunately all of the Maryland material, and the European also according to Seward, is porous and imperfectly preserved. Tempskya is common in Maryland and in the Wealden, and Velen- ovsky speaks of examining over 100 specimens from the Quader of Bohemia. 1Seward, Wealden F1., pt. i, 1894, pp. 148-159. 298 SYSTEMATIC PALEONTOLOGY TEMPSKYA WHITEI sp. nov. Plates XXXVII, XXXVIII Description.—Polystelic filicinean stems of large size. The steles numerous and small, anastomosing and giving rise to numerous petiolar strands. Entirely invested with a great mass of branching adventitious roots. The latter are of various sizes and show a central axial vascular strand surrounded by a decayed zone representing phloem and this in turn surrounded by a sclerenchymatous zone. These roots are poorly pre- served and it has been impossible to decide whether they are diarch as Seward has described them for Tempskya Schimperi from the English Wealden, or pentarch or hexarch as was asserted by Solms-Laubach. One of the best-preserved roots is shown in the exact center of the micro- photograph, reproduced on pl. xxxvili, fig. 1, which shows portions of 2 steles, the lower of which is in the act of forking, while the periphery of a larger stele is shown at the left side above. Pl. xxxvii, fig. 2, shows a transverse section entirely across a small specimen and fig. 1 on the same plate shows a longitudinal section which. cuts across several steles. It has not been possible to secure sections and properly study these singular fossils in time to include the results in the present publication ; further characterization and- histological description, together with a discussion of their botanical affinity, are reserved for a special contribu- tion. For the purposes of the present work they are included with a query in the order Marattiales, using that term in a broad sense so as to in- elude the Paleozoic Psaroniex. As they appear to be specifically distinct from the numerous described European forms they have been named as a slight token of esteem in honor of Mr. David White of the U. 8. Geological Survey. These remains bear a superficial resemblance to palm wood, in fact they were, in the case of the English species, originally referred to Palmacites and to Endogenites, both properly appellative of fossil palm wood. In the Potomac area fragments of these trunks are often of con- MARYLAND GEOLOGICAL SURVEY 299 siderable size, one being 39 cm. in length by 17 cm. in diameter. They are not uncommon and are considered by many as petrified palms, while others look upon them as fragments of bones of huge dinosaurs. Occurrence.—Patapsco ForMaTIoN. Valleys of Stony Run and Deep Run near Severn, Anne Arundel County, Patuxent Neck, Prince George’s ,County, Maryland. Collecttons—Johns Hopkins University, Goucher College. INCERTAE SEDIS Genus SCLEROPTERIS Saporta [Pal. Franc., tome i, 1873, p. 364] This genus was established by Saporta for the reception of certain forms of supposed ferns of Jurassic age previously referred to Lozop- teris Pomel, Sphenopteris Brongn., Dichopteris Zigno, and Pachypteris Brongn., but without completely absorbing any of these genera. He characterized it as follows: “ Frons rigide coriacea bi-tripinnata, pinnis pinnatipartitis, pinnulis basi plus minusve constrictis in rachin angus- tissime alatam latere inferiori decurrentibus integris vel antice incisis lobulatisque; nervatio immersa, sepius imperspicua, ut manifesta fit, e nervulis paucioribus a basi ramosis latere dorsali pinnularum oblique prodeuntibus constans.” It seems probable that Scleropteris, as at present constituted, is a composite genus, certain species of which may be ferns while others, such as those formerly referred to Pachypteris Brongn., may well be cycadaceous.” As developed in the Potomac beds it is represented by bi- or tripinnate coriaceous fronds with pinnatifid pinne more or less constricted and decurrent at the base, entire or incised on the anterior margin, with a flabellate venation immersed in the leaf substance. The genus is well developed, in the middle and the Upper Jurassic, both in this country and Eurasia, and has several Lower Cretaceous representatives. These include, in addition to the following Potomac form, two species from the Lakota formation of eastern Wyoming, and a third from the Neo- \ 1See Krasser, Jahrb. k. k. geol. Reichs., Bd. xlv, 1895, pp. 39-49. 300 SYSTEMATIC PALEONTOLOGY comian of Portugal. Heer described a species from the Kome beds of Greenland in 1874, but afterward transferred it to the genus Dicksoma. ScLEROPTERIS ELLIPTICA Fontaine Plate XX XIX, Figs. 1, 2 Scleropteris elliptica Fontaine, 1890, Mon. U. S. Geol. Survey, Vol. xv, 1889, p. 151, pl. xxviii, figs. 2, 4, 6; pl. xxix, fig. 1. Scleropteris elliptica var. longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 152, pl. xxviii, fig. 7. Scleropteris virginica Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 152, pl. xxviii, figs. 3, 5. Ctenopteris integrifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 158, pl. Ixii, fig. 2; pl. lxv, fig. 3 (non Font., 1906). Scleropteris elliptica Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 511. Scleropteris virginica Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xviii, 1905, p. 484. Description.—Frond bipinnate or -tripinnate, probably arborescent. Main rachis stout, its branches rather slender and straight. Pinne alternate or subopposite, broadly linear in general outline. Pinnules or segments lanceolate, becoming much reduced distad, directed upward ; with an acute apex and a narrowed decurrent base which produces a winged rachis. Usually a single vein enters each pinnule, soon diverging in a flabellate manner into several which are simple or fork once or twice before their termination in the margin. In one specimen there appear to be several veins entering a pinnule, suggesting the forms constituting the genus Ctenopteris. The veins are all immersed and difficult to make out with certainty. Texture coriaceous. The pinnules vary greatly in size, reflecting the individual variation in the species and that due to position on a single plant. Thus their dimensions range from 0.5 cm. to 3.4 em. in length, and from 1 mm. to 4 mm. in greatest width. Where the pinnules are more or less elongated and slender the veins approximate a parallel course. This species, which is seen to contain three supposed species described by Prof. Fontaine, is not uncommon in the older Potomac, to which it is confined, not occurring in the Arundel formation or outside the Mary- land-Virginia area. MaryYbLanp GEOLOGICAL SURVEY 301 Occurrence.—PatUxENT Formation. Fredericksburg, near Potomac Run, Dutch Gap, Kankeys, Chinkapin Hollow, near Telegraph Station (Lorton), and Cockpit Point (?), Virginia. Collection.—U. S. National Museum. Genus THINNFELDIA Ettingshausen [Abh. k. k. geol. Reichsanstalt, Band i, Abth. iii, No. 3, 1852, p. 2] The genus Thinnfeldia was proposed by Ettingshausen in 1852 with Thinnfeldia rhomboidalis as the type, for remains from the Lias of Steierdorf in Hungary. He characterized the genus in the following terms: “ Rami teretes vel subalati. Folia disticha, alterna oppositaye, rhom- — boidea, ovalia vel lanceolata vel linearia, flabellatim vel pinnatim venosa.”” After comparing his species, three in number, with Odontopteris, Pachypteris, Albertia, Dammara, Ginkgo, and Phyllocladus, Ettings- hausen was induced to place Thinnfeldia with the conifers, from its resemblance to the existing Phyllocladus. In 186% Schenk, on the basis of material from the Rhetic of Franconia, which showed epidermal and stomatal characters, referred Thinnfeldia to the cycads,! while Schimper, Saporta, Seward, and others refer it to the Filicales. Raciborski*® has furnished good evidence for the belief that some at least of the material from the European Jurassic is filicinean, as seems also to be the nature of the Potomac material, while the writer has shown * that the later American species which have been referred to this genus are in all probability gymnospermous. Various authors have called attention to the difficulty of distinguishing Thinnfeldia from such genera as Pachypteris Brongniart Dichopteris Zigno, Cycadopteris Zigno, Lomatopteris Schimper, and while the con- 1Schenk, Die fossile Flora der Grenzschichten der Keupers und Lias Frankens, 1867, p. 105, pl. xxvii. 2 Raciborski, Fl. Kopalna ogn. Glinek Krakowskich, 1894, see pl. xx, figs. 1, 2. ® Berry, Bull. Torrey Club, vol. xxx, 1903, pp. 438-445. 802 SYSTEMATIC PALEONTOLOGY sensus of opinion considers these forms as ferns, such a reference, al- though probable, cannot be said to be founded upon well-authenticated evidence, in fact Kerner in a recent discussion considers them cycadace- ous,' and Seward? makes the unwarranted suggestion of pteridospermic affinities. Thinnfeldia may be defined as follows: Frond pinnate, bipinnate, or tripinnate. Pinnules varying much in size and shape, mostly oblong, ovate-lanceolate, or oblong-obovate, decurrent and mostly confluent at base, coriaceous. Rachis broad and occasionally forked dichotomously. Midvein of the pinnules dissolved before attaining the apex into many simple or dichotomous laterals, which go off at a very acute angle, diverging in ascending, usually several times dichotomous. Fruiting forms unknown. The genus may be represented in the late Paleozoic, certainly there are Paleozoic forms which resemble it very closely. It is, however, espe- cially characteristic of the older Mesozoic. The Potomac species are four in number, and are for the most part poorly defined fragments of rare occurrence, Thinnfeldia Fontainet Berry being of most frequent occurrence as well as the best preserved form. THINNFELDIA FoNTAINEI Berry Plate XL, Figs. 4-7 Thinnfeldia variabilis Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 110, pl. xvii, figs. 3-7; pl. xviii, figs. 1-5 (non fig. 6 or Velenovsky, 1885. Fig. 6 is a Cladophlebis fragment of undeterminable specific affinity). Thinnfeldia Fontainei Berry, 1903, Bull. Torrey Bot. Club, vol. xxx, p. 448 Thinnfeldia variabilis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. -502, 528, pl. cx, figs. 7, 8 (non Fontaine 1894, 1896, which are referred to Cladophlebis virginiensis). Description.—* Frond bipinnate or tripinnate; rachises of the pinne stout, arborescent; pinnules lobed or toothed, with mostly ovate-obtuse lobes or teeth, short, varying much in size and nature according to posi- *Kerner, Jahrb. k. k. geol. Reichs., Band xlv, 1896, p. 39. * Seward, Fossil Plants, vol. ii, 1910, p. 538. MARYLAND GroLogicaL SURVEY 303 tion on the frond, passing in ascending, in the upper part.of the pinna», through toothed and undulate pinnules into entire ones; lower pinnules attached by the rachis alone, and deeply cut into broadly ovate-obtuse lobes; up higher in the pinnew, and on the frond they have ovate teeth and are attached by the middle of the much-narrowed base, and are slightly decurrent; towards the top the ultimate pinne pass into cre- nately lobed segments, and these into lobed and: toothed pinnules, like those lower down; all are acute; leaf-substance thick and leathery; mid- nerve neuropteris-like, and vanishing before attaining the apex of the pinnules; lateral nerves occur in the lower portions of the pinnules mostly in nerve groups; all go off very obliquely and fork usually several times, very fine and closely placed, but distinct.”—Fontaine, 1890. This species is the only one of this genus in the Potomac flora which is reasonably well characterized. It has been recorded from the Patuxent formation near’ Potomac Run, Virginia, and from the Shasta beds of California, but in both cases the identifications were erroneous, and it ‘appears to be confined to the Patapsco horizon where it is not common. ‘Tt resembles considerably in its general facies the older Mesozoic species of Thinnfeldia from Europe. Occwrrence.—PaTapsco Formation. Near Brooke (common), White House Bluff (rare), Virginia; Ft. Foote (rare), Maryland. Collection—U. S. National Museum. THINNFELDIA GRANULATA Fontaine Plate XL, Figs. 1, 2 Thinnfeldia granulata Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 111, pl. xxvi, figs. 10-12; pl. xxvii, figs. 1-5, 8; pl. clxix, fig. 1. Acaciephyllum longifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 279, pl. cxxxvii, fig. 6; pl. exxxviii, figs. 1-3. Acaciephyllum spatulatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 280, pl. cxxxviii, figs. 4, 6-9. Acaciephyllum microphyllum Fontaine, 1890, Mon. U. 8. Geel. Surv., vol. xv, 1889, p. 280, pl. cxxxviii, fig. 5. (?) Acaciephyllum variabile Fontaine, 1890; Mon. U. S. Geol. Surv., vol. xv, 1889, p. 281, pl. clxx, fig. 7. 20 304 SYSTEMATIC PALEONTOLOGY Celastrophyllum proteoides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 304, pl. cxivi, fig. 5. Acaciephyllum microphyllum Fontaine, 1906, in Ward, Mon. U. 8. Geol. Surv., vol. xlviii, 1905, p. 486. Description —* Frond bipinnate or tripinnate; rachises comparatively. stout; leaf-substance thick; pinnules varying in size and shape with their position on the pinne and frond; in shape they are ovate-elliptical to subrhombic, the lower ones irregularly cut into oblong to elliptical lobes; the lower surface of the pinnules has a very fine granulation be- tween the nerves, which can be seen distinctly only by the help of a lens; nerves closely placed, very fine but distinct on the under surface of the pinnules, repeatedly branching and diverging flabellately.”—-Fontaine, 1890. This species is rare at all the localities where it has been collected and is very poorly preserved. It includes the forms from the older Potomac which Professor Fontaine considered of a dicotyledonous nature under the name of Acaciaphyllum, but which are obviously identical with the type material of this species. A comparison of this author’s pl. cxxxviii, fig. 5, of Acaciephyllum with pl. elxix, fig. 1, of Thinnfeldia, will clearly show this. The present writer has carefully compared all of the available material, and there is not the slightest doubt but that the forms included in the foregoing synonymy are all fragments of the same species. The two specimens from the later Potomac at Federal Hill are retained and included with the earlier forms of Acaciephyllum referred to this species, although they probably represent one of the Celastrophyllum species so common at this locality. Their preservation is such that nothing definite can be made out, and they are, therefore, queried as being doubtfully determined. Forms from the Neocomian of Japan which resemble the present species in a general way are described by Professor Yokoyama as Glossozamites parvifolius and Adiantites lanceus, and similar forms have been frequently referred to Adiantites. Occurrence-—PaTUXENT Formation. Dutch Gap, near Dutch Gap, near Potomac Run, Telegraph Station (Lorton), Virginia. Paraprsco Formation. Federal Hill (?) (Baltimore), Maryland. Collection —U. 8. National Museum. Marytanp GEoLogicaL SuRVEY 805 THINNFELDIA ROTUNDILOBA Fontaine Plate XL, Fig. 3 Thinnfeldia rotundiloba Fontaine, 1890, Mon. U. 8. Geol. Surv., Vol. xv, 1889, p. 111, pl. xxvii, figs. 6, 7. Description.—< Frond bipinnate or tripinnate; principal rachis rather stout; pinnules with thick texture, alternate, broadly ovate in outline, obtuse, cut more or less deeply into subrhombic or broadly elliptical and rounded lobes; nerves numerous, closely placed, slender but distinct, repeatedly branching in the lower lobes, and diverging flabellately ; mid- nerve in the terminal lobe dissolving in branches some distance below the summit, and in its lower portion sending off very obliquely nerve bundles or branches which fork one or more times.”—-Fontaine, 1890. This fragmentary species is of little specific or other value. It repre- sents a form of rare occurrence and is very probably not specifically distinct from Thinnfeldia granulata. Occurrence-—PatTuxENT Formation. Fredericksburg, near Potomac Run, Virginia. Collection —U. S. National Museum. THINNFELDIA MARYLANDICA Fontaine Plate XL, Figs. 8, 9 Thinnfeldia marylandica Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 541, pl. cxiv, figs. 8, 9. Description At the Arlington localities, and nowhere else, a num- ber of fragments of a fern were found that seems to be a new species. While the portions of the pinne of this plant are not very rare, 16 in all, they are so fragmentary that it is difficult to make out its character. On the whole, it agrees best with the genus Thinnfeldia, so far as can be determined from the imprints. Still, it is quite possible that better specimens would show that it belongs to some other genus. The most complete specimen, Goucher College, No. 5450, shows no more than a portion of a detached ultimate pinna, or a lobed pinnule. This is repre- sented in fig. 8. Fig. 9 gives two such fragments not so complete as that given in fig. 8. These two, however, are so placed as to indicate that 306 SYSTEMATIC PALEONTOLOGY they were once attached to a common rachis, not now preserved. The pinnz or lobed pinnules partly overlap. The parts that are preserved appear to be the terminal ones of the pinna or pinnules, and they are not sufficiently well preserved to give their dimensions and shape. The nature of the incisions of the lamina, which represent either lobes or pinnules, can be made out and the nervation is remarkably distinct. This specimen is without number or locality label, but the Arlington material is so distinctive that there can be no doubt that it is from that locality. “The lobes or pinnules are very obliquely incised and are oblong in form, with the free ends obtuse lancet shaped. The incisions visible are not cut down to the midrib, but indicate that lower down on the portions shown they may be so, constituting pinnules. The midnerve or tachis of the pinna is distinct and somewhat flexuous. On each side of this midnerve parent nerves depart at a very small angle to enter the pinne or lobes. The parent nerve forks at long intervals, the principal branch of each fork keeping near the middle of the pinna or lobe, while the other branch forks some distance up. These minor nerves are quite remote from one another and sharply defined, though not very strong. “While this fern cannot be fully made out, it is clearly different from any previously found in the Potomac beds. It is confined to the Arling- ton localities.”—Fontaine, 1906. Any further discussion of such incomplete remains can serve no useful purpose. Occurrence.—ARUNDEL Formation. Arlington, Maryland. Collection—-Goucher College. Order LYCOPODIALES Family SELAGINELLACEAE Genus SELAGINELLA Beauvois [Prodr. Aetheog., 1805, p. 101] The Paleozoic representatives of the order Lycopodiales (Lepidoden- dron, Sigillaria, ete.), as is well known, were dominant members of that MARYLAND GEOLOGICAL SURVEY 307 flora with a large number of species and individuals. They were in gen- eral of a lofty arborescent habit, with a high structural organization. Mesozoic remains are extremely rare and ill defined, although several Cretaceous species have been described under the generic name Selag- mella. None, however, come from as low a horizon as does the Mary- land specimen.t The modern species are small in size and of wide geo- graphical distribution, especially within the tropics, where they are larger and show greater specific differentiation than elsewhere. About five hun- dred existing species have been described. They are heterosporous and possess a ligule, as do their Paleozoic allies, and like Lepidocarpon* and Miadesmia,’ among the latter, they are sometimes quasi-seedbearing.” The modern forms have doubtless been derived from Paleozoic forms which have always been herbaceous rather than from the complex arbo- recent types by reduction, one of the few herbaceous Paleozoic plants known, Miadesmia membranacea,’ suggesting what such an ancestral type .may have been like. SELAGINELLA MARYLANDICA Fontaine Plate XLI, Figs. 1, 2 Selaginella marylandica Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 553, pl. exv, figs. 9, 10. Description.—F ragmentary remains of dichotomously branching stems of sympodial habit with two laterally attached rows of minute leaves 1 and 1.5mm. in length. Leaf substance firm, with a thick midrib. Leaves somewhat falcate, widest near the base, which is slightly cordate. Possibly the leaves were four-ranked, the other rows being obscured or present on the counterpart of the impression which was not collected. 1See Halle, Hinige krautartige Lycopodiaceen Paléozoischen und Meso- zoischen Alters, Arkv. fiir Botanik, Stockholm, 1907, Band vii, No. 5. 2 Scott, Ann. of Botany, vol. xiv, 1900, pp. 713-717. 3 Benson, Rept. Brit. Assn. Adv. Sci., Belfast, 1902, p. 808. 4+Lyon, Bot. Gaz., vol. xxxii, 1901, p. 170. ° Bertrand, Ass. fr. Ad. Sc., 23e sess., Cen, 1895, ii, p. 588. Benson, Phil. Trans. Roy. Soc. Lond., vol. 199B, 1908, pp. 409-425, pls. xxxiii- XXXVii. 308 Systematic PALEONTOLOGY While the reference of this form to Selaginella is not conclusive it is certainly very suggestive of that genus in its superficial appearance, and no better disposition of it has suggested itself. Possibly future collections will fortunately disclose fruiting specimens which will conclusively settle the question. WHeer* has described a doubtful species from the Ceno- manian (Atane beds) of Greenland, and Velenovsky * another which is very similar to the Maryland form from the Perucer schichten of Bohemia. Occurrence—Parapsco Formation. Vinegar Hill, Maryland. Collection——Johns Hopkins University. order EQUISETALES Family EQUISETACEAE Genus EQUISETUM Linné [Sp. Pl., 1753, p. 106] Perennial rush-like plants with jointed stems, which are generally ridged and grooved, the ridges alternating at the joints. Much branched’ in the Potomac forms, the recent species often simple. Root stocks sub- terranean, often tuber-bearing. Leaves reduced to sheaths at the joints, the sheaths toothed. Spores (as far as known) all of one size and shape (isosporous). Sporangia borne on modified sporophylls (sporangio- phores) which are aggregated to form a definite cone (strobilus). These plants, which in the allied order Calamariales forms so dom- inant and imposing a group in the Paleozoic is almost entirely repre- sented in Cretaceous formations by forms referable to the family Equisetacee. A number of Carboniferous species of small size, which are based upon impressions of cones or stems with leaf sheaths like those of the modern forms, have been referred to the genus Hquisetum (or * Selaginella arctica Heer, Fl. Foss. Arct., Band vi, Ab. ii, 1882, p. 39, pl. xiii, fig. 5. * Selaginella dichotoma Velen., Farne béhm. Kreidef., 1888, p. 29, pl. ii, figs. 8-11. MaryLanp GEoLogioaL SURVEY 309 Equisetites). Their internal structure is unknown, and as some of the Calamariacee had leaves united in sheaths the remains of foliage from the older rocks is not unequivocal. The cone impressions, however, are not so easily disposed of, and it seems quite possible that the later species form.a continuous line of descent from some similar herbaceous Paleozoic stock which was plastic enough to adapt itself to varying sub- sequent conditions. With the opening of the Mesozoic age forms clearly allied to the re- cent genus are common fossils. These are largely stem or pith casts (de- tached diaphragms and tubers are also fossilized) and are often of large size, i. e., from 12 to 15cm. in' diameter and 8 to 10m. tall, quite as tall as the largest living species and not nearly so slender. It seems quite possible that some of these Triassic and Jurassic forms may have increased in diameter by the formation of secondary wood, as did so many of their Paleozoic allies. The later Mesozoic species of Hquisetum are much smaller than their Triassic and Jurassic ancestors, and are scarcely distinguishable from existing forms. These latter, commonly known as “ horse tail,” “ mare’s tail,” or “scouring rushes,” form a compact group of from twenty-five to thirty rather monotonously uniform species, growing usually in low and wet habitats and present on all the continents except Australia, although they are found as fossils in that region. They are present in tropical and arctic as well as in the temperate zones, and the majority are of small size, although one species, Hquisetum gigantewm Linné, which ranges from Cuba to Chile, is said to attain a height of about 8m., but remains very slender and not over 2 or 3 cm. in diameter. The Potomac forms are not important elements in the flora, although they are present in considerable abundance at some localities, nor are they at all well preserved. There are no apparent grounds for maintain- ing them as distinct from the rather widespread European forms of this -age, and they are therefore identified with the latter, whose geographical ranges are quite comparable to that. of such ubiquitous existing forms as Equisetum arvense Linné. 316 SysTEMATIC PALEONTOLOGY Equisetum BurcHarpti (Dunker) Brongniart Plate XLI, Figs. 3-6 Equisetites Burchardti Dunker, 1846, Monog. norddeutsch. Wealdenbild., p. 2, pl. v, fig. 7. Carpolithus cordatus Dunker, 1846, loc. cit., p. 22, pl. ii, figs. 7, 10. Carpolithus Huttoni Dunker, 1846, loc. cit., p. 22, pl. ii, fig. 8. Carpolithus Lindleyanus Dunker, 1846, loc. cit., p. 22, pl. ii, fig. 7. Equisetum Burchardti Brongniart, 1849, Tableau, p. 107. Equisetites Burchardti Unger, 1850, Gen. et Sp., p. 59. Equisetites Burchardti Ettings., 1851, Haidinger Abh., vol. iv, Abth. 1, p. 65. Equisetites Burchardti Wttings., 1852, Abh. k. geol. Reichs., Band i, Abth. iii, 1852, p. 10, pl. i, figs. 3, 4. Equisetum Burchardti Schimper, 1869, Traité Pal. Végét, tome, i, p. 264; tome iii, 1874, p. 453. Cycadinocarpus ? cordatus Schimper, 1870, Traité Pal. Végét., tome ii, p. 211. Cycadinocarpus ? Huttoni Schimper, 1870, loc. cit., p. 210. Cycadinocarpus Lindleyanus Schimper, 1870, loc. cit., p. 210. Equisetum Burchardti Schenk, 1871, Paleont., Band xix, p. 205 (3), pl xxii (i), figs. 1-5. Equisetites Burchardti Renault, 1882, Cours bot. foss., tome ii, p. 151. Equisetites Burchardti Saporta, 1890, Compt. Rend., tome cxi, p. 250. Equisetum virginicum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 63, pl. i, figs. 1-6, 8; pl. ii, figs. 1-3, 6, 7, 9. Equisetum marylandicum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 65, pl. ii, fig. 10. Rhizome of Equisetum sp. ? Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 66, pl. clxx, fig. 8. Equisetites Burchardti, Seward, 1894, Wealden Fl. pt. i, p. 27, pl. i, figs. 5, 6. ; Equisetum Burchardti Saporta, 1897, Fl. Foss. Port., p. 66, pl. xv, fig. 7. Equisetum virginicum Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 650 pl. clx, fig. 1. Equisetum virginicum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 483, 486, 519. Equisetum marylandicum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 517, 557, pl. cix, fig. 10. Description.—“ Equisetites caule tenni multiarticulato striato, striis subacutis, vili-x, eque distantibus, vaginis tumidis lanceolato-dentatis.”— Dunker, 1846. Stems branching freely, the branches slender or approaching the stems in size, ranging from 1:5 mm. to 8 mm. in diameter. Internodes -8 cm. to 2.2 cm. in length. Sheaths slightly swollen, 2 mm. to 10 mm. MaryLanp GEOLOGICAL SURVEY 311 in length, with ovate or lanceolate teeth with short, acute tips which may be somewhat obtuse in some specimens. Tubers abundant, two or more in number at the nodes, in shape oval, somewhat constricted at points of attachment, as preserved about 7 mm. by 8 mm. in diameter. The preservation of all of the Potomac specimens is poor, and the great majority are partially or wholly decorticated and otherwise much macerated, indicating prolonged submergence before fossilization. In neither of the specific forms established by Fontaine are there any con- stant characters which serve to distinglish them from the widespread Equisetum Burchardti of Europe, with which they are here identified. This species was described by Dunker from the Wealden of Hanover, along with its tubers in various stages of preservation. These he failed to recognize as such, describing them as various species of Carpolithus. Schenk in 1871 gave a much better diagnosis of this species and also pointed out the true nature of Dunker’s various species of Carpolithus. The species is common in the Wealden of England and has been re- corded from the Barremian of Austria, the Valanginian or Lower Neo- comian of Portugal, and the Lakota formation in the Hay Creek coal field of Wyoming. Hquisetum ushimarense Yokoyama* from Japan is a closely allied if not identical form. Occurrence.—PaTUXENT ForMATION. Terra Cotta (obscure rhizome) and New Reservoir (common), District of Columbia; Dutch Gap, Cock- pit Point, Telegraph Station (Lorton), Virginia. Parapsco Forma- tion. Federal Hill (Baltimore), Maryland. Collection —U. 8S. National Museum. Equisetum LyEtur Mantell Plate XLI, Figs, 7, 8 Equisetum Lyelli Mantell, 1833, Geol. S. E. England, p. 217, fig. 52, 1-3 on p. 245. Equisetites Lyelli Bronn, 1848, Index Pal., p. 464. Equisetum Lyelli Brongniart, 1849, Tableau, p. 107. Equisetum Lyelli Géppert, 1849, in Bronn, Geschichte der Natur, Band iii, p. 13. Equisetites Lyelli Unger, 1850, Gen. et Sp., p. 60. Equisetites Lyelli Morris, 1854, Brit. Foss., p. 8. 1Journ. Imp. Univ. Tokyo, vol. iii, 1890, p. 39, pl. xi, figs. 1-3. 312 SYSTEMATIC PALEONTOLOGY Equisetum Lyelli Schimper, 1869, Traité Pal. Végét., tome i, p. 265; tome, ili, 1874, p. 453. Equisetum Lyelli Schenk, 1871, Paleont., Band xix, 1871, p. 5 (207), pl. i, figs. 10-13. Equisetites Lyelli Renault, 1882, Cours bot. foss., tome ii, p. 150. Equisetum Lyelli Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 65, pl. i, fig. 7; pl. ii, figs. 4, 5. Rhizome of Equisetum sp. ? Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 65, pl. ii, fig. 8. Equisetum Lyelli Dawson, 1892, Trans. Roy. Soc. Can., vol. x, sec. iv, p. 83, fig. 1. Equisetites Lyelli Seward, 1894, Wealden F1., pt. i, p. 24, pl. i, fig. 4. Equisetum Lyelli Fontaine, 1898, in Weed and Pirsson, 18th Ann. Rept. U. S. Geol. Surv., pt. iii, p. 481. Equisetum Lyelli Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 301, 417, 514, pl. Ixxii, figs. 12-14. Equisetites Lyelli Neumann, 1907, Neues Jahrb. Beilage, Band xxiv, p. 77, pl. i, fig. 2. Description.“ Caulis epigezus cylindricus articulatus ramosus, inter- nodia 2 centim. longa, 10-13 millim. in diametro, rami 5 millim. in diametro, folia sterilia vaginata, vaginee 1 centim. longe, dentes lineares acuminati persistentes.”—Schenk, 1871. A somewhat larger species than the preceding, with stems .6 cm. to 1.5 cm. in diameter. Internodes 2 cm. to 2.5 cm. in length. Single branches are of frequent occurrence at the nodes in the foreign material, and it is probable that the smaller Potomac specimens represent detached branches. The sheaths are about a centimetre in length, with numerous linear acuminate teeth. Internodes finely striated. The American remains are usually fragments of stems, and like those of the preceding species are generally very poorly preserved. Described originally from the Wealden of Pounceford, England, this species has been recognized at Fredericksburg, Dutch Gap, and Chinkapin Hol- low (?) by Fontaine. Dawson found it in the Kootanie of Canada and Fontaine reports it from the same formation at Geyser, Montana. It has also been recorded recently from the Neocomian of Peru.* Occurrence.—PaTUXENT Formation. Springfield (?), Maryland; Fredericksburg, Chinkapin Hollow (?), Dutch Gap, Virginia. Collection—U. S. National Museum. 1Neumann, loc. cit. MaryLanp GroLocicaL SuRVEY ; 313 Phyum SPERMATOPHYTA cuss CYCADOPHYTAE Order BENNETTITALES Family CYCADEOIDEACEAE Genus CYCADEOIDEA Buckland [Proc. Geol. Soc. Lond., vol. i, No. 8, 1827, pp. 80, 81] Trunks usually low and more or less conical or ovoid in shape; gen- erally simple; covered with a thick armor formed by the appendicular and reproductive organs, the former consisting of the persistent bases of the leaf-stalks surrounded by a dense mat of ramentum; trunk crowned with a large terminal vegetative bud often poorly preserved or obliterated by decay before fossilization; ramentum made up of very fern-like, multicellular hairs or scales, and extensively developed. Its resistant nature led to its ready’ petrifaction so that normally the fossil trunks show the ramental areas as prominent partitions separating the subrhombic angular cavities left by the leaf-stalks which decayed or were shed before fossilization. These leaf-scars are arranged in a more or less exact quincunx order, and usually in two sets of spirals, one dex- tral and the other sinistral, the one generally more emphasized than the other. The generic separation and nomenclature of the fossil cycad trunks (so called) based on their external form and surface features is one beset with many difficulties, and a great variety of names have been pro- posed for their reception." Following Professor Ward, the Maryland forms are all referred to Buckland’s genus Cycadeoidea, which has pri- ority among the names proposed for tuberous armored types of cycad 1 Such as Clathraria Schimper 1872, Yatesia Carruthers 1870, Fittonia Carr. 1870, Platylepis Sap. 1875, Bucklandia Presl 1825, Mantellia Brongn. 1828, Tysonia Font. 1889, Bolbopodium Sap. 1875, Cylindropodium Sap. 1875, Pala- tylepis Sap. 1875, Clathropodium Sap. 1875, Cycadeomyelon Sap. 1875, Rau- meria Carr. 1870, Williamsonia Carr. 1870, Orossozamia Carr. 1870, ete., many of course being synonyms. 314 SYSTEMATIC PALEONTOLOGY trunks. An alternative course largely followed abroad would be to consider them referable to the genus Bennettites of Carruthers. This is the view advocated by Seward* and adopted by Potonié in Engler and Prantls’ Naturlichen Pflanzenfamilien. Solms-Laubach * has already referred many of the species of Bennett- ites to Cycadeoidea restricting the former name to specimens showing lateral axillary fructifications. Seward* would use Cycadeoidea in a somewhat different sense, for all cycadean trunks, whether short and thick or tall and slender, which are covered with persistent leaf-bases, Fic. 5.—Transverse section of a partly emergent but still folded frond of Cycadeoidea ingens deeply embedded in ramentum, X 4 (after Wieland). and which show no trace of lateral reproductive shoots such as character- ize Bennettites gibsonianus Carruthers and allied forms, and which there is no reason for including in the family Cycadacee. It has been shown by Wieland * that fruition was the culminant event in the life of most, if not all, the trunks which he investigated, fruits not being produced Seward, Jurassic Flora, 1904, pt. ii, p. 44. 2 Capellini and Solms-Laubach, 1891, Mém. R. Accad. Sci. Inst. Bologna (5), vol. ii, p. 161. 3 Seward, loc cit. 4Wieland, American Fossil Cycads, 1906. MARYLAND GEOLOGICAL SURVEY 815 until vegetative maturity. It would follow, if the method just men- tioned were pursued, that a Bennettites which was not mature enough to show indications of flowering would be a Cycadeoidea, or an accident of preservation might equally determine the question, an altogether un- desirable state of affairs.’ It is very doubtful if specific determinations based upon external form and surface features have any real value aside from their practical utility, and it seems quite probable, as various writers have pointed out, NY ea Be KRSER a Wier a NAOT hee eg Encephalartos wS : 0 Meactpzama Lo" Stanasrie RE P Le AB Fic. 6.—Sketch map of the world showing the approximate distribution of the existing cycads. oe Wa and as is fully admitted by Prof. Ward, that his determinations based on megascopic characters cannot be looked upon as having real specific value, but simply as the most expedient method of handling the immense amount of material which passed through his hands, the specific names affording convenient pegs on which to hang the morphological and structural details which will result from a study of their histological features. Nine species have been recognized by Prof. Ward in the 1See Wieland, Amer. Journ. Sci., vol. xxv, 1908, p. 97. 316 Systematic PAaLronToLoGy Maryland area, and these are here retained unaltered, although it is very probable, as already stated, that this is too large a number. In view of the constantly increasing evidence of the abundance and extent of variation in the cycad-like plants during the Mesozoic, it has seemed proper to adopt the suggestion of Professor Nathorst+ and con- sider them as representing a distinct class, the Cycadophyte. Concern- ing their segregation within the class we know as yet too little to estab- lish natural lines of cleavage. The genus Cycadeoidea is here retained in the larger group denominated the Bennettitales in contradistinction to the Cycadales, which term is reserved for forms resembling the modern types, as a matter of convenience and not as representing an altogether natural grouping. The most interesting features of the Mesozoic cycadophytes are their fructifications and fruiting habits, for a knowledge of which we are in- debted to Carruthers,’ Solms-Laubach,* Lignier,‘ Nathorst,” and Wieland.° Among all of the five score or more species of existing cycads the dis- tribution of which is shown on the accompanying sketch map (fig. 6) the fructifications are of a simple and rather uniform type. The staminate or pollen-producing organs have the form of a cone, the pollen sacs being attached in groups to the lower surfaces of the cone scales (sporophylls). In all but one of the nine existing genera into which these species are grouped the ovulate or seed-bearing fructification is also a cone, each scale (sporophyll) of which bears two seeds. In the genus Cycas, how- ever, a far more primitive condition exists, the ovules being borne along the edges of carpellary leaves (sporophylls) which spring from the main axis exactly as do the foliage leaves, which they greatly resemble. This ‘is by far the most archaic and fern-like method known among modern +Nathorst, Beitr. z. Kennt. einiger Mesozoischen Cycadophyten, Kgl. Svenska Vetens.-Akad. Handl., Band xxxvi, No. 4, 1902. ? Carruthers, Trans. Linn. Soc. Lond., 1870, vol. xxvi, pp. 675-708, pl. liv-Lxiii. 2 Solms-Laubach, Ann. of Botany, 1891, vol. v, pp. 419-454, pls. xxv, xxvi. *Lignier, Végét. Foss. de Normandie, Cen, 1894. 5 Nathorst, Kgl. Svenska Vetens-Akad. Handl., Band xlv, No. 4, 1909, Ibid., Band xlvi, No. 4, 1911. ® Wieland, loc. cit. MaryLanp GEOLOGICAL SURVEY 317 seed plants, and the cycads still further emphasize this resemblance to ferns in their mode of fertilization, i. e., by means of ciliated motile sperms. When we come to consider the method and organs of fructification of the Mesozoic Bennettitales (so called), instead of finding them of a simpler type, as we might expect, we find a much greater complexity, while on the other hand the vegetative structures are simpler than is the case in the existing cycads. The fructifications in the former as exemplified in the genus Cycadeoidea are long axillary bodies inserted \ Fic. 7.—Restoration of an unexpanded bisporangiate strobilus with some of bracts removed, about one-half natural size. (After Wieland.) in large numbers among the crowded leaf bases (see Cycadeoidea mary- landica). About half their length is taken up by the peduncle or stalk on which spirally arranged bracts are borne, and these completely invest the essential organs (see fig. 7). Distad, this peduncle expands into a receptacle from the rim of which springs a whorl of staminate, com- pound, fern-like sporophylls on which the pollen is produced, not in simple anthers, but in compound pollen-sacs comparable with the synangia of the marattiaceous ferns. These Cycadeoidea “ stamens ” in their habit suggest a comparison with the ovulate fructification named by Renault e 818 SYSTEMATIC PALEONTOLOGY Cycadospadiz milleryensis from the Permian of Autun, France.” The seed-bearing sporophylls of Renault’s interpretation would then be morphologically the fertile leaflets, of a single compound sporophyll. Within the whorl of “stamens” of the Cycadeoidea “ flower,” which were wilted or shed quite early, an ovoid or conical, ovulate cone was borne. The orthotropous ovules were situated at the ends of long slender pedi- cels, and the interstices were packed with sterile appendages (inter- seminal scales) which, with their expanded tips formed a protective envelope for the developing seeds, suggesting an angiospermous pericarp Fic. 8.—A. Radial longitudinal section of an ovulate strobilus of Cyca- deoidea, somewhat reduced. (After Wieland.) B. Semi-diagrammatic longitudinal section of a bisporangiate strobilus of Cycadeoidea, about one-fourth natural size. (After Wieland.) as shown in fig. 8 in actual section at A, and semi-diagrammatically at B. The gigantic “stamens,” if they may be called stamens, which is a term of very doubtful propriety, have not been found unfolded, but as the American material is immature Wieland rightly supposes that they eventually opened out as shown in part in fig. 8, B. 2Renault, Bassin Houill, d’Autun, 1896, fase. 4, pt. 2, p. 329, pl. 73, figs. 1-7. MARYLAND GEOLOGICAL SURVEY 319 Since these fructifications are obviously reduced lateral branches, the bracts at least, if not the staminate and ovulate appendages as well, repre- senting leaves, it follows that the ancestral cycadophytes were more or less slender, unarmed, branching forms somewhat similar to the Triassic Anomozamites so admirably restored by Nathorst,’ possibly with terminal instead of axillary fructifications, a not very essential difference, if, in- deed, the fructifications are axillary in Anomozamites. Detached and more or less imperfect cycadean fructifications of the same general character as those we have just been considering, and pre- served as impressions, are common fossils in Mesozoic deposits the world over, and are usually referred to the genus Williamsonia. Although their true affinity was long ago suggested by the late Prof. Williamson,” Fie. 9.—Two views of the type of Williamsonia virginiensis, one-half natural size. (After Fontaine.) their real nature has been the occasion of a great deal of argument. Williamsonias have been described by Ward" from the Maryland Po- tomac, but the specimens appear to be nothing but poorly preserved and distorted cone fragments of the coniferous genus Abictites, so that a figure of a true Williamsonia from the Virginia Potomac is introduced for comparison with Wieland’s restorations. In habit the Williamsonias were probably borne on much longer peduncles, so that in those forms where they were axillary they projected considerably beyond the armor, 1Nathorst, loc. cit., p. 13. ? Williamson, Trans. Geol. Soc. Lond., 1837, ser. 2, vol. v, pp. 223-242. * Ward, Mon. U. S. Geol. Surv., No. xlviii, 1906, p. 554, pl. exv, fig. 11. 21 320 SYSTEMATIC PALEONTOLOGY others, like Williamsonia gigas, are known, in which the fructification appears to be terminal. The discovery of the bi-sporangiate nature of Cycadeoidea inaugurated a renewed interest in the cycadophytes. Professor Nathorst has recently described Williamsonias which were unisexual,’ and Wieland, Arber and Parkin, and others,” have advanced the theory that these Lower Cre- taceous forms were not very different from the ancestors of the higher plants (Angiosperme) represented in the existing flora by the order Ranales, entirely overlooking the wide difference in structure throughout the vegetative body, where the characters are much more conservative and furnish a much safer clue to filiation than do the reproductive parts, especially when of the indicated plasticity of those of the cycadophytes. We may now proceed to the enumeration of species, brief descriptions of which are adapted from Prof. Ward’s more voluminous treatment (loc. cit.). CYCADEOIDEA MARYLANDICA (Fontaine) Capellini and Solms-Laubach Plate XLIT Cycas sp., Tyson, 1860, First Report State Agric. Chem., Maryland, p. 42. Bennettites sp., Carruthers, 1870, Trans. Linn. Soc., London, vol. xxvi, p. 708. Cycadeoidea sp., Fontaine, 1879, Am. Journ. Sci., 3d ser., vol. xvii, p. 157. Tysonia Marylandica Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 193, pl. clxxiv-clxxx. Cycadeoidea Marylandica Capellini and Solms, 1892, Mém. Real. Accad. Sci. Inst., Bologna, ser. v, vol. ii, pp. 179, 180, 186. Cycadeoidea Marylandica Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, p. 9. *Nathorst, A. G., Ueber Williamsonia, Wielandia, Cycadocephalus und Weltrichia, Kg]. Svenska Vetens.-Akad. Handl., Band xlv, No. 4, 1909. *Arber, E. A. N., and Parkin, J., On the Origin of Angiosperms, Journ. Linn. Soc. Lond., vol. xxxviii, 1907; The Relationship of the Angiosperms to the Gnetales, Annals of Botany, vol. xxii, 1908, pp. 489-515. Scott, D. H., The Flowering Plants of the Mesozoic Age, in the Light of Recent Discoveries, Journ. Roy. Mier. Soc., 1907, pp. 129-141. Wieland, G. R., The Williamsonias of the Mixteca Alta, Bot. Gazette, vol. xlviii, 1909, pp. 427-441. MaryLANnp GroLocioaL SURVEY 821 Oycadeoidea Marylandica, Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 416, pls. lxxxi, Ixxxii, lxxxiii, figs. 1, 2, 4; pl. lxxxiv, figs. 1, 2; pl. lxxxvii, figs. ii, 3, 5, 6, 7; iii, 1, 4; iv, 4, 5, 12-14; v, 2, 3, 5-7, 17; pl. Ixxxviii, pl. Ixxxix, figs. ii, 3, 4, 7; iti, 2, 5, 8; 90, 91, 92. Cycadeoidea Marylandica Wieland, 1906, American Fossil Cycads, fig. 1. Description —Trunks of medium or rather large size, almost always more or less laterally compressed so as to be elliptical in cross-section, conical in shape or slightly narrowed near the base, with a terminal bud set in a slight depression at the summit, simple, or in one specimen, apparently having one branch ; mineral constitution very variable accord- ing to mode of preservation, but usually not hard, flinty, nor heavy and compact; 25 to 45cm. high, 24 to 40cm. in longer, and 12 to 26cm. in shorter diameter, with a girth of from 70cm. to 1 m.; organs con- stituting the armor proceeding at a right angle to the axis except above, where they are ascending, and near the base, where they are sometimes slightly descending; leaf scars arranged in two series of spiral rows crossing each other usually at a different angle to the axis of the trunk, the angle varying from 30° to 75°; scars usually subrhombic, i. e., with the lateral angles nearly equal and the vertical ones unequal, the lower more acute than the upper, the latter often reduced to a mere groove, or wanting entirely, and the two upper sides together forming an arch, or an irregular horizontal line; 15 to 25 mm. in breadth by 6 to 15 mm. in height; remains of the petioles usually present in the scars at different distances from the summit, often bearing evidence of having been dis- articulated at a natural joint, sometimes indicating the existence of two such joints at different depths in the scars; vascular bundles rarely vis- ible under an ordinary lens, but occasionally seen in the form of a row near the outer margin all round the leaf base with a few near the centre; ramentum walls usually with a more or less distinct line marking the junction of the parts belonging to adjacent petioles, sometimes with a distinct layer of less compact tissue between these, occasionally, but rarely, affected with pits or small bract scars, especially in the angles; reproductive organs usually abundant, often solid and protuding, gener- ally more or less distinctly marked in the centre by the remains of the essential organs and surrounded by bract scars in several concentric 822 SYSTEMATIC PALEONTOLOGY rows, but often decayed in various degrees, leaving corresponding funnel- shaped cavities, commonly elliptical in cross-section, wider than high, very variable in size, the major axis 15 to 40 mm. and the minor 10 to 30 mm.; armor thin, 2 to 5 cm., usually joined to the internal parts by a clear line, but without measurable thickness, but sometimes very irregularly so joined, and occasionally showing a thin libro-cambium layer; woody zone 3 to 10 cm. thick, usually with two or three more or less distinct rings, the outer or parenchymatous zone thicker and firmer than the inner or fibrovascular zone; medulla usually homogeneous in structure, elliptical, the major axis 8 to 17 cm., the minor 3 to 9 cm. This is historically the most important species of Maryland Potomac eycads, most of the original types found by Tyson belonging to it. It is also the most abundant species, and was the first species of cycad trunk from America to receive scientific mention. The plate is from an original daguerrotype sent to Sir Wm. Dawson, and by him to Carruthers, who mentioned it in a note to his paper On the Cycads from the Second- ary Rocks of Great Britain (loc. cit.) This was discovered by Tyson (loc. cit.) about: 1860 between Balti- more and Washington, who collected in all perhaps 10 or 12 of these trunks. These excited much interest at the time, but did not receive scientific description for over 20 years, although Tyson sent pictures of them to various geologists, both in this country and abroad, and pre- sented specimens to Professors Dawson and Marsh, and perhaps others. The exact geological horizon in the Potomac Group has not been es- tablished with certainty for any except this one trunk, and for this reason the localities will not be given for the other species, since, as the specimens do not occur in situ, the point where they eroded out or were plowed up has little significance, since they have all come from the same circumscribed belt. It is quite possible that they are all of Pa- tuxent age, and may have been reworked in later, even Pleistocene, de- posits. The exact age of the trunks is of little biologic significance, since the frond impressions are present throughout the various forma- tions of the Potomac Group, the absence of ee trunks being due entirely to physical conditions of deposition. MaryLanp GroLogioaL SURVEY 323 Occurrence.—PatTuxENT Formation. Link Gulch, near Arbutus, Baltimore County. Collections.—Johns Hopkins University, Yale University, U. 8. Na- tional Museum, Maryland Academy of Sciences, Goucher College of Baltimore, McGill University, and South Carolina College. CYCADEOIDEA TysoNIANA Ward Plate XLITI Cycadeoidea Tysoniana Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, p. 11. Cycadeoidea Tysoniana Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 432, pl. Ixxxvii, figs. 1, 5; v, 4; pl. xciii. Description—Trunk medium sized or large, more or less compressed laterally ; leaves slightly ascending; leaf scars arranged in spiral rows, 9mm. high, 22mm. wide, subrhombic, empty to some depth, petioles persistent at base, the vascular bundles arranged in one row near the exterior and a group near the centre, often persisting after the decay of the remaining substance; ramentum walls thin, often with a layer of spongy substance in the middle, wrinkled on the edges; reproductive organs few and small; armor 5 cm. thick; libro-cambium zone sometimes distinct, 3mm. thick; woody zone 6 cm. to 8cm. thick; consisting of a broad, parenchymatous layer 4 to 6cm. thick, and a narrow inner vas- cular zone 1em. thick, the latter usually between open tissue without and within, its inner wall strongly marked with longitudinal grooves ; medulla distinct and homogeneous, light and porous. This species differs from Cycadeoidea marylandica in the larger leaf scars, thinner walls, thicker armor, and the great paucity of reproduc- tive organs, and from Cycadeoidea McGeeana in the normal shape of the trunk and its greater size. ? * CycapDEoIpDEA McGzrana Ward Plate XLIV Cycadeoidea McGeeana Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, p. 12. : Cycadeoidea McGeeana Ward, 1906, Mon. U. S. Geol. Surv., xlviii, 1905, p. 434, pl. Ixxxvii, figs. ifi, 3, 10; iv, 15; v, 8, 9, 19, 20; pl. Ixxxix, figs. ii, 1, 8; iii, 4, 9, 10; pl. xciv. 824 SYSTEMATIC PALEONTOLOGY Description.—Trunks low and flat, with ample diameter, sometimes three times as thick as high, yellowish, brown, or nearly black, more or less porous and spongy, and of low specific gravity; leaves and repro- ductive branches set nearly at right angles to the axis; leaf scars ar- ranged somewhat definitely in quincunx order and disposed in spiral rows around the trunk, small and uniform in shape, subrhombic with the vertical angles obtuse, the lateral ones acute, narrow-elongate, 6 cm. to 10 cm. in vertical by 16 mm. to 20 mm. in lateral dimensions, aver- aging 8 mm. by 20 mm., usually empty, by the disappearance of the leaf bases, at least to a considerable depth; ramentum walls thin, often less than 1mm., with or without evident commissure, and with occasional punctuations; axes of inflorescence few and scattering, sometimes pro- jecting, sometimes cavitous from the decay of the essential organs, sur- rounded by obtusely triangular or somewhat crescent-shaped bract scars ; armor 4cem. to 5em. thick; liber and cambium sometimes distinguish- able; woody zone usually divided into two or three rings; medulla large, porous. A very distinct species of low and squat trunks, some of them having almost the form of a car wheel, only a very small part of which can be due to vertical compression. The external organs, however, closely re- semble those of Cycadeoidea Tysoniana. CYCADEOIDEA FONTAINEANA Ward Plate XLV Cycadeoidea Fontaineana Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, p. 13. Cycadeoidea Fontaineana Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 439, pl. Ixxxvi; pl. Ixxxvii, figs. i, 1; iii, 2, 6, 8; iv, 1, 7, 9: v, 1, 10, 11, 13, 14, 16, 18, 21; pl. Ixxxix, figs. i, 1; iii, 1, 3, 6, 7, 11; pl. xcev; pl. xevi; pl. xcvii; pl. xeviii. Description.—Trunks small and low, usually much compressed or flattened vertically, light brown to whitish in color, often spongy or porous, and of low specific gravity; leaves and fruiting branches set nearly at right angles to the axis; leaf scars not obviously arranged in spiral rows, variable and irregular in shape, usually with four angles and MaryLanp GEoLoGioaL SURVEY 325 four curved sides, often in the form of a cross, rarely subrhombic, small, 8mm. to 12 mm. in vertical and 14mm. to 25 mm. in lateral measure- ment, averaging 10 mm. by 19 mm.; ramentum walls thick, 4 mm. to 10 mm., usually without commissure or punctations; leaf bases rarely present; when so, spongy or porous, without visible bundles; terminal bud 6 cm. high, 65 mm. broad at the downwardly convex base, definitely bounded below, symmetrically conical above, consisting of a mass of densely matted bracts imbricated along a central axis; reproductive or- gans few and imperfectly defined, usually cavitous in the centre and sometimes surrounded by irregular-shaped bract scars; armor rather thin, 2 cm. to 4.cm.; liber and cambium obscure; woody axis divided into several rings, sometimes consisting of a loose, open structure separated by thin, firm plates, the inner face next the medulla definitely marked by the remains of vessels and medullary rays; medulla large, marked on the external surface by thin longitudinal ridges or lamelle varying from 1 cm. to 3 cm. in length, the ends overlapping adjacent ones (Cycadeo- myelon Saporta), internal parts coarse and porous or somewhat cham- bered. This species resembles Cycadeoidea McGeeana in the general form of the trunks, but the external organs are very different, the most striking distinction being the very thick walls. CYCADEOIDEA GOUCHERIANA Ward Plate XLVI Cycadeoidea Goucheriana Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, p. 14. Cycadeoidea Goucheriana Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 451, pl. Ixxxvii, fig. i, 3; pl. Ixxxix, fig. i, 3; pl. xcix. Description—Trunks large, cylindrico-conical with elliptical cross section, 30 cm. to 50 cm. high, 25 em. to 50 cm. in diameter, light colored and of low specific gravity, somewhat chalky and friable; lower leaves somewhat deflexed, upper ones ascending the line between the two definite and encircling the trunk near the middle; leaf scars arranged in two sets of spiral rows, both having nearly the same angle to the axis, 45° or 326 SYSTEMATIC PALEONTOLOGY greater; scars variable in size and shape, chiefly subrhombic to nearly triangular, with curved or fluted sides, inner wall of the tubes marked by a raised line around it; scars averaging 11 mm. in vertical and 23 mm. in lateral measurement; leaf bases usually absent or only adhering to the bottom of the scars; ramentum walls thick, more or less divided into irregular lamine or scales with fissures between them, their outer edges ragged; reproductive organs numerous, well marked, irregularly scat- tered over the surface, most abundant at the narrower sides, usually cavitous in the centre, sometimes solid and protuding, surrounded by concentrically arranged, crescent-shaped bract scars, sometimes well ex- posed and clearly distinguishable; armor 3 cm. to 5 cm. thick, separated from the wood by a definite line; woody zone 4m. thick, consisting of an outer parenchymatous ring 3cm. thick, a thin ring of loose, open structure, and two thin plates separated by another ring of coarse cells divided by radial partitions, the inner walls of both plates marked with scars of the medullary rays, the pattern different in the two cases, the scars on the inner plate 13 mm. long, those on the outer longer and tapering upward; medulla large, elliptical, tapering upward, of a coarse homogeneous structure. CycAaDEOIDEA UHLERI Ward Plate XLVIT Cycadeoidea Uhleri Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, p. 14. Cycadeoidea Uhleri Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 454, pl. Ixxxvii, fig. iv, 10; pl. c. Description.—Trunks small, 28 cm. high, 20 em. in diameter, 50 cm. to 60 cm. in girth at the thickest part, circular, or only slightly elliptical in cross-section, conical or somewhat cylindrical-conical in shape, con- tracted at the base, leaf scars definitely arranged in quincunx order and spiral rows around the trunk, one of these sets of rows dscending at an angle of 45° to the axis, the other at a much greater angle; subtriangular, the upper side arched and sometimes slightly grooved, lateral angles acute, inferior angle obtuse or rounded; scars uniform in size, 18mm. wide and 9mm. high; ramentum walls 4mm. to 5mm. thick, commissure MARYLAND GEOLOGICAL SURVEY 327 distinct, the whole punctured with minute rhombic, triangular, or ellip- tical bract scars deeply penetrating the structures; leaf bases usually wanting, but sometimes nearly filling the cavities; vascular bundles few, arranged in a row near the upper side of the petiole, and others scattered over other parts; petioles all reflexed or pointing downward at a strong angle; reproductive organs numerous, situated directly over the leaf scars, i. e., axillary, elliptical in outline, 15mm. wide, 10mm. high, the centre occupied by the remains of the essential organs or by a circular cavity where these have disappeared; bract scars small and numerous, somewhat curved and arranged concentrically, also passing out into the ramentum walls; armor 3cm. to 5em. thick; woody zone 15mm. to 35 mm. thick, divided into two or three rings; medulla about 5 cm. in diameter, cylindrical or elliptical, according to the shape of the trunk; heterogeneous in composition, being traversed by dike-like plates of a hard substance dividing it into chambers, often wanting, leaving a hollow centre to the trunk. CycaDEOIDEA Bispinst Ward Plate XLVIITI Cycadeoidea Bibbinsi Ward, 1897, Proc. Biol. Soc., Washington, vol. xi, pigeraties Bibbinsi Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 456, pl. Ixxxiii, fig. 3; pl. Ixxxiv, fig. 3; pl. Ixxxv; pl. Ilxxxvii, figs. i, 2, 4, 6, 7; ii, 1, 2, 4, 8, 9, 10, 11; iii, 5, 7; iv, 2, 3, 6, 8, 11; v, 12, 15; pl. lxxxix, figs. i, 5; ii, 2, 5, 6; pl. ci-civ. Description —Trunks large, 40cm. to 60cm. high, laterally com- pressed, girth of largest specimen 1m., of next in size 88cm., shorter axis of cross-section one-half to two-thirds of longer axis, contracted toward the summit, terminating in a conical bud 30 cm. high, or, where this is wanting, in a concave depression, thoroughly silicified throughout, heavy and solid, of a dark color; all the organs of the armor nearly at right angles to the axis of the trunk; leaf scars arranged spirally around the trunk in imperfect quincunical order, subrhombic, the lower angle much sharper than the upper, the latter sometimes reduced to a curve, 14 mm. high, 26 mm. wide; ramentum walls moderately thick, usually 828 SYsTEMATIC PALEONTOLOGY solid ; vascular bundles of the petioles arranged in a row entirely around them and near the margin of a cross-section, also sometimes a few near the centre; spadices abundant, irregularly scattered over all parts of the surface, usually showing the marks left by the essential floral organs or a central cavity occupying their place, surrounded by curved or crescent-shaped pits concentrically arranged in several rows and set concave to the axis of the spadix, representing the involucral bracts; armor varying from 25 mm. to 75 mm. in thickness, this variation often great in different parts of the same specimen; cambium layer indistinct ; liber zone not generally distinguishable from the wood; the latter in two or three zones, medullary rays faint; medulla well marked, homogeneous, usually spongy in appearance. This species represents a type quite distinct from all the others, the eycadean trunks of Maryland being divisible, according to habit, into two classes, one of which would embrace all the forms included in the six species above described, and the other those that have been referred to this species. The fact that the rock in the Jatter is always firm, hard, and heavy, and usually dark colored, is not merely an accident of preser- vation, but results in some obscure way from the nature of the vegetable tissues. The trunks are generally larger and the leaf scars much larger, though they have nearly the same form and arrangement. The repro- ductive organs are more abundant and usually very regular and definite in their character. This species, with Cycadeoidea Fontaineana, is scarcely less numerous than Cycadeoidea marylandica, these three being by far the most abun- dant of the Maryland trunks. CYCADEOIDEA CLARKIANA Ward Plate XLIX Cycadeoidea Clarkiana Ward, 1906, Mon. U. 8. Geol. Surv., vol. xlviii, 1905, p. 472, pl. Ixxxix, figs. i, 2, 4; pl. evi. Description—Trunks rather large, tall and subcylindrical or barrel- shaped, laterally compressed, unbranched; rock rather hard, of a light- ash color and average specific gravity; organs of the armor horizontal Marytanp GEoLogicaL SuRvEY 829 or somewhat descending; rows of scars from left to right making an angle with the axis of 45°, those from right to left an angle of 80°; leaf scars subrhombic or irregular in shape and variable in size, 15 mm. to 18 mm. wide, 10 mm. to 15 mm. high; leaf bases present, sunk about lem. below the surface, porous; vascular bundles not visible on the cross-sections, but distinct on the eroded surfaces; ramentum walls very thin and sharp edged, thickening below to 3 mm. to 5 mm. hard, destitute of markings or division line between the plates; reproductive organs obscure and reduced to pitted areas on the eroded surface; armor 3 cm. thick, the leaf bases passing insensibly into the woody axis; wood 2 cm. thick, in four layers or rings; outer layer 1 cm. thick, chiefly composed of the elements of vascular tissues passing upward and outward through it and curving over at the outer margin to enter the deflexed leaf bases ; fibrous zone of three rings, the outer and inner consisting of loose, open tissue, largely decayed in the only specimen that shows them, leaving a fissure, the middle ring hard and firm, forming a plate surrounding the medulla, 5mm. thick, its inner surface regularly marked with the scars of the medullary rays, which are elliptical in shape and disposed in alternating rows; medulla very large and prominent, elliptical in cross- section, thickest in the middle of the trunk to conform to its shape, which it chiefly determines, the shorter diameter varying from 9 cm. to 15 cm. and the longer from 14cm. to 18 cm., coarse grained and homogeneous in structure, its surface where exposed handsomely marked by the ridges and flutings of the bases of the medullary rays rising out of it. This is a very distinct species and the only one of the Maryland Poto- mac species that has the tall subcylindrical form. CYCADEOIDEA FisHera Ward Plate L Cycadeoidea Fishere Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 470, pl. lxxxvii, fig. iii, 9; pl. ev. Description.—Trunks rather small, about 30 cm. high and 20 cm. in diameter, conical, unbranched; rock soft, light buff colored, of low specific gravity; leaf stalks strongly inclined, making an angle with the 330 SYSTEMATIC PALEONTOLOGY axis of the trunk of nearly 45°; rows of scars very distinct, spirally arranged around the trunk, those from left to right making an angle with the vertical axis of about 45°, those from right to left of about 30°, the latter much the more obvious and curving upward, so that the angle varies from 45° below to 25° above; leaf scars subrhombic, the two upper ones often forming a gentle arch, sometimes nearly a horizontal line, making the alveoli true triangles, the lower 2 cm., the upper 12 mm. wide, about 1 em. high, diminishing toward the summit; leaf bases usually present, soft, shady, and fine grained; rarely reaching the sur- face, generally sunk to a depth of 5mm., sometimes of 2em.; vascnlar bundles often visible, either as slight protuberances on the eads of those leaf bases that rise highest in the scars, or as small dots on those that lie deeper, or as a series of ridges running down into the scars where the central portion is deeper than the outer portion, the rows 0.5 mm. from the outer margin with occasional faint traces of more central bundles; ramentum walls when normal about 5mm. thick, of a rather firm consistency, presenting a continuous sharp ridge in the direction of the rows of scars from right to left, without visible commissure; repro- ductive organs abundant, one in the axil of each leaf, small and doubt- less mostly abortive, occupying wide triangular spaces between the leaf scars, causing the walls to appear abnormally thick; spadices always present and flush with the walls, elliptical or circular in cross-section, . the larger ones 2 cm. wide and 1 cm. high, often much smaller ; involucral scales abundant, occupying most of the space between the walls, con- centrically arranged in groups of thin, crescent-shaped scars, which are . always somewhat depressed and contain the bases of the scales; essential organs visible at the center of the best preserved spadices, but often want- ing and represented by a cavity; armor 3 em. thick; woody cylinder con- sisting of two layers or rings, the outer, or cortical parenchyma 2 cm. thick, open and loose in structure, the large vascular strands passing upward and outward through it to enter the leaf bases, where they sud- denly arch over and assume the downward course of the leaves, the inner or fibrous zone, 5 mm. thick, very distinct from the outer, the strands rising from its outer surface and not penetrating it, its fibres being é MaryYLAND GEOLOGICAL SURVEY 331 longitudinal ; its inner walls showing the longitudinal rows of the alter- nating ovate scales of the medullary rays. Genus DIOONITES Miquel [Over de Rangschikking der fossiele cycadee; Tijdschr. v. d. Wissen. Naturk. Wetensch., Deel iv, 1851, p. 211] The question of the proper generic reference of cycad fronds is a much mooted one, and considerable has been written as to the proper generic name for the fossils here referred to Dioonites. Nathorst (loc. cit., p. 46) and Seward (loc. cit., p. 75) have been foremost to question this refer- ence, the former proposing the genus Zamiophyllum for fronds of this type from the Neocomian of Japan because the pinne are slightly nar- towed towards the base and the latter advocating their reference to Zamites. Prof. Fontaine (1906, p. 246 et seq.) certainly makes out a strong case for their retention in Miquel’s genus which was characterized as follows: “ Frondes pinnate, rigide, crassz. Foliola densa pantentis- sima suprema nune subimbricata, lanceolata vel lineari-lanceolata, recta vel subfalcata, acuta vel acutiuscula, basi tola latitudine inserta, inferne retrorsum subdecurrentia, nervis cum margine parallelis equalibus sub- tus, distinctioribus, cum sulculis stomatiferis alternantibus.” Bornemann in 1856 makes use of Miquel’s genus, referring to it sev- eral additional species including the one so common in the Potomac Group, which Ettingshausen had previously referred to Pterophyllum. Schimper (1870) also adopts it and gives a somewhat unintelligible Latin diagnosis. The genus is also used by Schenk and Saporta. Fon- taine in 1890, misled by Schimper’s “ pro- e¢ decurrentibus,” gives a rather faulty generic diagnosis which is corrected in his later work (1906). Dioonites may be distinguished from Pterophyllum by the insertion of the pinnez on the plane of the upper surface of the rachis, and from Zamites by the decurrent pinnz, for while they are slightly narrowed toward the base in some specimens they are attached by their whole width and run somewhat over and down the rachis, their insertion being some- what lateral on the upper face of the rachis, the upper epidermis of the 332 SYSTEMATIC PALEONTOLOGY two being continuous. The angle of divergence of the pinne is of minor importance since it will obviously vary greatly in proceeding from the base to the apex of the frond. It may be unfortunate that the name suggests a relationship to the modern genus Dion Lindley, but the time has passed when generic names have other functions than mere names, and the suggested relation to Dion, if it is suggested, is not wider of the mark than the implications of the term Zamites. The latter name is more properly retained for frond types in which the pinne are articulated to the rachis, often de- veloping a prominent basal callosity and frequently found as detached fossils, which is not the usual method of occurrence of Dioonites, in which the pinne, as might be imagined from their structure, are markedly persistent. The genus is a widespread and characteristic member of the Wealden and other Lower Cretaceous floras, and although Seward includes the Cenomanian Pterophyllum saxonicum of Reich in the synonymy of Dioonites Buchianus it is very doubtful if this species extends above the Lower Cretaceous. In its typical form it is a very prominent element in the oldest Potomac flora. Dioonitzes Bucuianus (Httingshausen) Bornemann Plates LI, LIT Pterophyllum Buchianum Ettingshausen, 1852, Abh. d. k. k. Geol. Reich- sanst., Band i, Abth. iii, No. 2, p. 21, pl. i, fig. 1. Dioonites Buchianus Bornemann, 1856, Org. Rest. d. Lettenkohlengruppe Thiringens, p. 57. Dioonites Buchianus Schimper, 1870, Pal. Végét., tome ii, p. 149. Pterophyllum Buchianum Schenk, 1871, Paleontographica, Bd. xix, 1869, p. 8, pl. iii, fig. 5. Dioonites Buchianus Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 182, pl. Ixviii, fig. 1; pl. Ixix, figs. 1, 3; pl. Ixx, figs. 2, 3; pl. Ixxi, fig. 1; pl. lxxii, figs. 1, la, 2, 2a; pl. xxiii, figs. 1-8, 3a, 3b; pl. Ixxiv. Zamiophyllum Buchianum Nathorst, 1890, Denks. Akad. Wiss., Wien, Band / lvii, pp. 46, 49, pl. ii, figs. 1, 2; pl. iii; pl. v, fig. 2. Zamiophyllum Buchianum Yokoyama, 1895, Journ. Coll. Sci., Imp. Univ., vol. vii, p. 223, pl. xx, fig. 1; pl. xxiii, fig. 6; pl. xxvii, figs. 5a, b; pl. xxviii, figs. 1, 2. MaryLanp GroLogicaL SURVEY 333 Zamites Buchianus Seward, 1895, Wealden Flora, pt. ii, p. 79, pl. iii, figs. 1-5; pl. iv; pl. viii, fig. 1. Dioonites Buchianus Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 244, 479, 483, 486, 517, 534, 538, pl. xvi, figs. 16, 17; pl. evii, fig. 2; pl. eviii, fig. 1. Dioonites Buchianus ? Knowlton, in Diller, Bull. Geol. Soc. Am., vol. xix, 1908, p. 386. Description —* P. fronde pinnata, pinnis circa 1-2 dm. longis, 4-7 mm. latis, alternis, linearibus, subremotis, subangulo acuto adnatis, nervis creberrimus, tenuissimis instructis; rhachide crassiuscula.”—Ettings- hausen, 1852. Fronds very large, attaining probably the length of a metre or more; maximum width 25 cm. to 30 cem.; rachis stout, epidermis of the rachis and pinne thick and durable; leaves thick and leathery; pinne varying much in dimensions, distance, shape, and termination; linear-acute, sometimes closely placed, sometimes remote, those in the middle part of the frond the most commonly found, these diverge at an angle of 45°, those of the upper part become more and more oblique, until at the sum- mit they occur in the prolongation of the rachis; the terminal pinne much shorter and narrower than those lower down; length varying, attaining in some cases 25 cm.; slightly narrowed to the base and at- tached by the whole width of the base, obliquely placed and decurrent; veins fine, not prominent, very closely packed, forking at the base, paral- lel, and terminating without convergence.in the summits of the leaflets; some of the outer ones ending in the margins a little below the summit. In the material collected in the vicinity of Dutch Gap Canal on the James River, Virginia, the leaf substance is often preserved on the im- pressions as a thick lignitic sheet. From such a specimen collected over 20 years ago by Prof. Fontaine, at the locality known as the Fishing Hut, above Dutch Gap Canal (U. S. N. M., No. 3773), pieces of the epidermis were suitably prepared for microscopic examination, and a number of interesting features were made out. Below a magnification of 100 diameters the outlines of the epidermal cells appear as rows of small, narrow-walled, almost square rectangles, the irregularly scattered stomata showing as cells of darker color. With a higher power (385 334 SyYsTEMATIC PALEONTOLOGY diameters) the outlines are still substantially rectangular, but the walls are seen to be not straight but irregularly waved or undulatory, as shown in the figure. This waving is less regular and less emphasized than in similar figures given by Schenk for the genus Pterophyllum, and seems to be more pronounced in the lateral and less marked in the transverse walls. The cells are small, about 7 microns (2/3 obj.) in diameter, and the walls are thin. The stomata are numerous and without regular arrangement, but the guard cells are all oriented alike and parallel, presumably to the long axis of the pinnule. This feature also differs from their arrangement in Pterophyllum, as shown by Schenk, where Coo oe CO tr PCCW OD Fie. 10.—Cuticle of Dioonites Buchianus viewed from within, x 385. eS they are less numerous and without parallel orientation. The guard cells are two in number and stout in form. Their upper surface is just at or slightly below the surface of the cuticle, and’ they are quite deep, becoming narrower inward. These features will enable observers to distinguish Dioonites from fragments of similar appearance like those of Nagetopsis in cases where the cuticle is preserved. This fine plant is very abundant in the lower Potomac, along the James River in Virginia, the splendid specimens figured on pls. li and lii coming from Sailors’ Tavern. The remains from Maryland, which have been identified as this species, are extremely poor and questionable, those so identified with a query by Fontaine from the locality on the Bewley estate being here omitted as undeterminable. MaryYLANpD GronogicaL Survey 335 It is a widespread older Cretaceous type, first found in the Barremian Wernsdorfer schichten near Teschen in Austrian Silesia, and since found in great abundance at various localities in the Neocomian of Japan. It also occurs in the English Wealden, although Fontaine is of the opinion that most of the forms which Seward so identifies are incorrectly de- ° termined. Prof. Fontaine has also recorded this species from the Shasta and Horsetown beds of California, and from the Glen Rose beds of the Trinity Group of Texas. Occurrence—PatvuxENT Formation. Cockpit Point, Telegraph Sta- tion (Lorton), Kankeys, Trents Reach, Dutch Gap and vicinity, Vir- ginia; New Reservoir (?), District of Columbia. ARuNDEL Formation. Arlington (?), Maryland. Collections.—U. S. National Museum, Goucher College. Genus PODOZAMITES F. Braun {In Miinster, Beitr. Petref., Heft vi, 1848, p. 36] This genus was proposed by Friedrich Braun for certain species for- merly included in the genera Zamia Brongn. and Zamites Presl, which had pinnate, distant, alternate leaflets contracted basally and with paral- lel veins which converged at thé base, and usually at the apex. Zamites distans of the latter author, a Rhetic and Liassic form, becomes the type. Braun’s characterization is as follows: “Blatter gefiedert; Fieder- blaéttchen abwechselnd fernstehend, durch zusammenziehung an der Basis gleichsam gefusst. Nerven von der Austrittstelle an bogig, in der Mitte fast grade und parallel zur Spitze der Fieder verlaufend.” The genus at this time included six species, embracing besides distans and lanceolata four forms regarded by Braun as new species which, however, were not named or described. Schimper emended the genus in 1870, listing ten species, four of which were of Lower Cretaceous age and the balance older. His diagnosis is as follows: “ Folia magnitudine medi- ocri, rachi tenui. Foliola distantia, patentia, oblonga, ovato- et lineali- oblonga, apice obtuse acuminata vel rotundata, basin versus sensim an- gustata, subpedicellata, pedicello defluente articulato, decidua, nervis ex 1Pal. Végét., tome ii, 1870, p. 158. 22 336 SYsTEMATIC PALEONTOLOGY infima basi dichotomis, dehine simplicibus, erectis, parallelis, apicem versus convergentibus.” Three score or more species have since been described, some of them coming from strata as late as the Tertiary. Post-Mesozoic forms which have been referred to this genus are of very doubtful propriety, however, since they probably represent fragmentary remains of monocotyledons in no wise related to the Mesozoic types. The axis is usually slender and the leaflets are somewhat irregularly placed. They vary greatly in size and outline and are many veined, the veins not converging apically to any extent in extremely narrow- leafed forms. Leaflets usually found detached, and hence probably deciduous. The genus is usually included in the Cycadacee, although some authors have been inclined to include it among the Araucariew.” It is wide- spread and more or less abundant type from the Triassic to the Upper Cretaceous, and may possibly include unallied forms, the character of the material, however, not admitting of as much precision in determinations as would be desirable. Podozamites was not an especially important element in the flora of the Potomac Group, and what specimens have been found are frag- mentary and poorly defined. They have been confused with hoth Zamites and Nageiopsis in the past, and are, it must be confessed, dis- tinguishable with difficulty. Undue specific differentiation is unde- sirable, and it is very doubtful if the eleven species which Saporta (1894) ‘recognizes from the Mesozoic of Portugal could be recognized a second time even by their deseriber. PopoZAMITES INZQUILATERALIS (Fontaine) Berry Plate LIT, Fig. 1 Nageiopsis obtusifolia Fontaine,” 1890, Monogr. U. S. Geol. Surv., vol. xv, 1889, p. 200, pl. Ixxxv, fig. 7. Nageiopsis inequilateralis Fontaine, 1890, Monogr. U. 8. Geol. Surv., vol. xv, 1889, p. 200, pl. Ixxxv, fig. 6. 1Seward, Jurassic FI, pt. i, 1900, p. 241. * The specific name obtusifolia cannot be used for a species of Podozamites, as there has been quasi use of this combination by Heer, Handl. Kiéngl. Sven. Vet. Akad. (Fl. Foss. Arct., Band iv, Abth. i), 1876, p. 39, pl. viii, fig. 6. MaryLanD GEoLoGIoaL SURVEY 337 ~ Nageiopsis montanensis Fontaine, 1906, in Ward, Monogr. U. S. Geol. Surv., vol. xlviii, 1905, p. 312, pl. Ixxiii, fig. 7. Nageiopsis obtusifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 484. Podozamites inequilateralis Berry, 1910, Proc. U. S. Natl. Museum, vol. xxxviii, p. 194. Description.—“ Leaves short in proportion to width, very obtuse, at- tached by a short slightly twisted pedicel, broadly elliptical or oblong in shape, broadest near the base, slightly inequilateral at base; nerves fork- ing once or twice near the base and then parallel to near the summit, where they are a little crowded together, the outer ones ending in the margins a little below the apex.”—Fontaine,' 1890. The description of N. inequilateralis is an alliteration of that of the preceding NV. obtusifolia. It is based on a single specimen. Veins are twenty-two in number, much thicker than in Nageiopsis, and like those in NV. acuminata, which has also been referred to Podozamites. They converge toward the tip of the leaf, which is missing in the specimen. Leaf pedicellate at base. N. montanensis, from the Kootanie at Geyser, Montana, is based on a single detached leaflet with nineteen or twenty veins, convergent in the obtuse tip. There is absolutely no ground for including it in Nagetopsis. The inequilateralis specimen comes from Kankeys, Virginia, and ob- tusifolia was found near Potomac Run and at Cockpit Point, Virginia. These imperfect forms are suggestive of Podozamites affinis (Schenk) Schimper* of the Wernsdorfer schichten, but are not representative enough for accurate comparison. It seems probable that Podozamites ellipsoideus Sap.’ represents addi- tional occurrences of this species in the Neocomian and Albian of Portu- gal, and that the forms from the Neocomian of Japan which Yoko- yama* identifies with Podozamites pusillus Velen. are the Asiatic rep- 1Schenk, Paleont., Band xix, 1869, p. 13, pl. ili, fig. 8. 2 Saporta, Fl. Foss., Portugal, 1894, pp. 87, 174, pl. xvi, fig. 31; pl. xxxii, figs. 8, 9; pl. xxxiii, fig. 5; pl. xxxv, fig. 12. ? Yokoyama, Mesozoic Plants from Kozuke, Kii, Awa and Tosa, Jour. Coll. Sci., Imp. Univ., Japan, vol. vii, 1895, p. 222, pl. xx, figs. 2, 3b, 4, 5, 7. 838 SYSTEMATIC PALEONTOLOGY resentatives of this same form. It is doubtful if the Bohemian specimens are distinct. Occurrence.—Paruxent Formation. Kankeys, Cockpit Point, near Potomac Run, Virginia. Collection —U. 8. National Museum. PopOZAMITES SUBFALCATUS Fontaine - Plate LITI, Figs. 2, 3 Podozamites subfalcatus Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 179, pl. lxviii, fig. 6; pl. clxx, fig. 9. Zamites ovalis Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889 (pars). p. 173. Description.—* Leaves unknown; leaflets subfalcate, narrowly ellip- tical to strap-shaped, obtuse or subacute, gradually narrowed to the base so as to form a broad, short pedicel, thick and leathery; nerves slender, and not well disclosed, forking near the base, then nearly parallel to near the tips, where they converge.”—Fontaine, 1890. This species was based upon rare and detached fragments Hoenn, the 72d milepost, near Brooke, and was compared by its describer with P. ovatus (Schenk) Schimp., and P. affinis (Schenk) Schimp. It is prac- tically identical with the forms from the Cenomanian of Bohemia, which Velenovsky * refers to Podozamites Hichwaldi Schimp., and is not dis-_ tinguishable from many of the fine specimens of this Jurassic species figured by Heer.’ Occurrence.—PaTUxENT Formation. Telegraph Station (Lorton), Virginia. Pararsco Formation. Near Brooke, Virginia. Collection—U. S. National Museum. PoDOZAMITES ACUTIFOLIUS Fontaine Plate LIII, Fig. 4 Podzamites acutifolius Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 181, pl. Ixxx, fig. 6; pl. lxxxv, figs. 10, 15; pl. Ixxxvii, fig. 1; pl. clxx, fig. 2. *Velenovsky, Gym. bohm. Kreidef., 1885, p. 11, pl. ii, figs. 9, 10, 23. * Heer, Fl. Foss. Arct., Bd. iv, Abth. i, 1876, p. 36, pl. vi, fig. 22c; pl. vii, fig. Te; pl. viii, figs. 1-4. MaryLanp GroLogioaL SurvEY 339 Nageiopsis acuminata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 201, pl. Ixxxv, fig. 11. Podozamites acutifolius Fontaine, 1893, Proc. U. S. Nat. Museum, vol. xvi, p. 266, pl. lxxxvi, fig. 7. Description Leaflets ovate-acuminate, widest toward the base, abruptly rounded to the short inequilateral pedicel. Sides straight, the whole outline suggesting a large leaf of the modern Araucaria Bidwilli and identical in size, outline, and venation with the usual type of leaves of Dammarca Mooret from New Caledonia. Veins about 20 in number, forked basally and converging conspicuously toward the apex. Length 3.5 em. to Yom., greatest width 8mm. to 17 mm. The most complete and best specimen of this species is the one which formed the type of Nageiopsis acuminata of Fontaine, and although he says “nerves not seen,” the venation is remarkably clear after twenty years, and shows conclusively that it cannot be referred to Nagetopsis. This species is also present in the Glen Rose beds of the Trinity in the Texas area. Occurrence.—PatuxENt Formation. Near Telegraph Station (Lor- ton), Dutch Gap, Virginia. Patspsco Formation. Deep Bottom, near Brooke, Virginia. Collection.—U. S. National Museum. Popozamires Know ttont Berry Plate LIII, Fig. 7 Zamites angustifolius Hichw., 1868, Lethea rossica, tome ii, p. 39, pl. ii, fig. 7. ' Podozamites angustifolius Schimper, 1870, Pal. Végét., tome ii, p. 160. (non Schenk, 1868). Podozamites angustifolius Heer, 1876, Fl. Foss. Arct., Band iv, Abth. i, p. 36, pl. vii, figs. 8-11; pl. viii, figs. 2e, 5. Podozamites angustifolius Heer, 1876, Ibid., Abth. ii, p. 45, pl. xxvi, fig. 11. Podozamites angustifolius Heer, 1878, Ibid., Abth. ii, p. 22, pl. v, figs. 11b, 12. 3 Podozamites angustifolius Lesq., 1884, Cret. and Tert. FI, p. 28. Podozamites angustifolius Lesq., 1892, Mon. U. S. Geol. Survey, vol. xvii, p. 27, pl. i, fig. 4. Podozamites angustifolius Newberry, 1896, Mon. U. S. Geol. Survey, vol. xxvi, 1895, p. 44, pl. xiii, figs. 1, 3, 4 (non fig. 2). 340 SYSTEMATIC PALEONTOLOGY Podozamites angustifolius Moller, 1903, Kgl. Svensk. Vetensk. Akad. Handl., Bd., ix, pl. i, figs. 8-12, 17b. Nageiopsis recurvata Fontaine, 1906, in Ward, Mon. U. 8S. Geol. Surv., vol. xlviii, 1905, p. 552, pl. exvi, fig. 2 (non Fontaine, 1890). Zamites tenuinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 528. Podozamites Knowltoni Berry, 1909, Bull. Torrey Club, vol. xxxvi, p. 247. Description —* Foliolis elongato-lineali-lanceolatis, centim. 6 circiter longis, infra medium millim. 5 latis, basin versus margine inferiore subitius angustatis quam superiore, decurrentibus, sat approximitis et erecto-patentibus.”—Schimper, 1870. This species has a very wide range, both geological and geographical. It is common in the Jurassic of high latitudes in Russia (the type re- gion), Siberia, Bornholm, and Spitzbergen. In the Lower and Upper Cretaceous indistinguishable remains are rather widely distributedk These occur in the Patapsco formation of the Potomac River valley, the Raritan formation of New Jersey, and the Dakota Group of Kansas. Whether or not they were specifically identical with the Jurassic forms cannot be proven, although they present no character aside from differ- ence in geological horizon to warrant their separation. Occurrence—Patapsco Formation. Vinegar Hill, Fort Foote, Mary- land; Mt. Vernon, Virginia. Collection.—U. 8S. National Museum. PopOZAMITES DISTANTINERVIS Fontaine Plate LITT, Figs. 8, 9 Podozamites distantinervis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 179, pl. Ixxix, fig. 9; pl. lxxxii, fig. 4; pl. lxxxiii, figs. 1, 2, 6, 7; pl. lxxxiv, figs. 1, 2, 8, 10, 14, 15; pl. Ixxxv, figs. 12, 16. Podozamiies pedicellaius Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 180, pl. Ixxvi, fig. 1; pl. Ixxviii, fig. 7; pl. lxxxii, fig. 5 (non Fontaine, in Ward, 1906). Podozamites distantinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 479, 516 (non pp. 165, 281, 573). Description.—-“ Leaves comparatively large, pinnate; leaflets large, elongate-elliptical in form, varying a good deal in size, maximum width varying from 27 mm. to 40 mm., usually comparatively broad, full length MaryYLaNnp GEoLoGIcaL SURVEY 341 not seen, but ranging from 11 cm. to over 14 cm., obtuse or subacute at tip, usually somewhat narrowed toward the base, and at the base rather abruptly rounded off into a short pedicel ; nerves strong, quite remote, forking at or near the base, and then parallel to near the tip, where they converge and connive more or less.”—-Fontaine, 1890. With the added amplification that the pedicel is somewhat variable in length, this species readily includes those forms named P. pedicellatus by Fontaine, which are otherwise identical with the type material. This is the commonest species of Podozamites in the Potomac Group, where it is confined, however, to the earliest formation, the Patuxent. It is not uncommon at Fredericksburg, but most of the specimens are fragmentary, as might be expected in leaves of this size preserved in rather coarse deposits. In life this must have been a very handsome species, and it appears to be quite distinct from any that have been hitherto described. Professor Fontaine has recorded this species from Cape Lisburne, Alaska, but it does not occur there.’ Possibly Podozam- ites nervosa Newberry (non-Schimper), described from the Kootanie of Montana, should be referred to this species, but in the absence of the base this cannot be demonstrated with certainty. Occurrence.—PATUXENT FoRMATION. Fredericksburg, Potomac Run, Dutch Gap (?), Virginia; 16th Street, District of Columbia. Collection.—U. S. National Museum. PopozaMITEs LANoEOLATUS (L. & H.) F. Braun Plate LITI, Figs. 5, 6 Zamia lanceolata Lindley and Hutton, 1836, Foss. F1., vol. iii, pl. exciii. Zamites lanccolatus F. Braun, 1840, Verzeich. Kreis.-Nat.-Samml. Bayreuth Petrefact., p. 100. . Podozamites lanceolatus F. Braun, 1843, in Miinster, Beitr. Petrefacten- kunde, Band ii, pt. vi; p. 33. Podozamites proximans Conrad, 1869, Amer. Jour. Sci. (ii), vol. xlvii, p. 361, tf ; Podozamites lanceolatus Schimper, 1870, Pal. Végét., tome ii, p. 160. * Knowlton, in Collier, Bull. U. 8. Geol. Survey, No. 278, 1906, p. 29. 342 ~ S¥stematic PALEONTOLOGY ? Podozamites minor.Heer, 1882, Fl. Foss. Arct., Bd. vi, Abth. ii,. p. 44, pl. xvi, fig. 8. Podozamites lanceolatus Velenovsky, 1885, Gymn. Bohm. Kreidef.. p. 11, pl. ii, figs. 11-19, 24. Podozamites lanceolatus Dawson, 1886, Trans. Roy. Soc., Can., vol. iii, sec. iv, p. 6, pl. i, fig. 3. Podozamites distantinervis Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 179 (pars). Podozamites lanceolatus Lesq., 1892, Mon. U. S. Geol. Surv., vol. xvii, p.. 28, pl. i, figs. 5, 6. Podozamites angustifolius Newb., 1896, Mon. U. S. Geol. Surv., vol. xxvi, p. 44, pl. xiii, fig. 2 (non figs. 1, 3, 4). Podozamites angustifolius Hollick, 1904, Bull. N. Y. Bot. Garden, vol. iii, p. 410, pl. Ixxi, fig. 8. Podozamites lanceolatus Penhallow, 1905, Summary Geol. Surv., Can., 1904, p. 9. Podozamites lanceolatus Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, p. 110, pl. xxiv, figs. 17-20. Podozamites pedicellatus Font., 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, p. 532, pl. exiv, fig. 1 (non other references). Podozamites distantinervis Font., 1906, in Ward, Mon. U. 8S. Geol.” Surv., vol. xlviii, 1905, pp. 165, 281. Zamia washingtoniana Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii,.1905, p. 503 (pars), pl. cxi, fig. 2 (non. fig. 1). '‘Podozamites’ lanceolatus Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i; p. 120, pl. xiv, fig. 4. Podozamites lanceolatus Hollick, 1907, Mon. U. S. Geol. Surv., vol. 1, p. 35, pl. ii, fig. 1. < Description.—* Pinnis distantibus, alternis oppositisve, elongatis, hasi sensim angustatis, inferioribus lanceolato-linearibus, ‘superioribus elon- gato-ellipticis; nervis crebris.”—Schimper, 1870. This is a species of great geological range, ‘being recorded from the Jurassic upward to the Upper Cretaceous. The geographical range is equally great, embracing two continents, N orth America and Europe. It is quite probable that the species is composite but no certain grounds for: segregation are apparent. While some students may doubt the wisdom of correlating both Lower and Upper Cretaceous forms with a species which is essentially a Jurassic type, specific differentiation founded merely upon stratigraphy has gone astray so often that in cases like the present synthesis may well precede MARYLAND GEOLOGIOAL SURVEY 343 analysis, and it might be added that this was the view taken by Hollick! with reference to material from Glen Cove, Long Island, and by Vele- novsky* in studying the Cenomanian flora of Bohemia. Forms indistinguishable from the type of this species occur in both the Patuxent and Patapsco formations of the Potomac Group, as well as in the Kootanie of Montana and British Columbia. As found in the Maryland-Virginia area the pinnules are always detached, lanceolate in outline, pointed at both ends and widest toward the base: Length about 11 cm.; greatest width about 12 mm. Occurrence.—PaTUXxENT Formation. Telegraph Station (Lorton), Virginia. Patapsco Formation. Ft. Foote, Maryland; Mt. Vernon, Virginia. Collection—U. S. National Museum. Genus ZAMITES Brongniart [Prodrome, 1828, p. 94] The genus Zamites is strictly a form-genus for the reception of cycadean fronds which resemble in a general way those of recent Zamias. It has been used in a somewhat varying and rather vague sense by vari- ous authors since its proposal by Brongniart in 1828. Proposed at a — time when but two types of modern cycad fronds, Cycas and Zamia, were recognized, it shows some of the characteristics of the modern genera Zamia, Macrozamia, Ceratozamia, etc. Afterwards Brongniart* aban- doned his older use of the genus Zamia Linné as indicative of too definite a relation to the modern species which by that time had become segregated into a variety of genera and recharacterized Zamites as fol- lows: “Ce genre est caractérisé par ses folioles parfaitement entiéres, non tronquées au sommet, mais aigués ou arrondies, non rétrécies ou légérement contractées 4 la base; 4 nervures parallales entre elles, et au 1 Hollick, Mon. U. S. Geol. Surv., vol. 1, 1907, p. 35. ey 2 Velenovsky, Gymn. Bohm. Kreidef., p. 11, pl. ii, figs. 11-19, 24, 1885. me - 5’ Brongniart, Tableau, 1849, p. 61. 4 344 SYSTEMATIC PALEONTOLOGY bord de la foliole, et par conséquent convergentes vers le sommet; fines et égales entre elles, trés rarement bifurquées lorsque la foliole est élargie dans sa partie moyenne.” Braun’s genera Podozamites and Pterozamites were included as subgenera. Zamites has been redefined by various subsequent authors notably Bornemann,’ Saporta,* Schimper,’ Schenk,’ Seward,’ etc., and it will suffice in this connection to quote the definition of the latter author, which is as follows: “ Frond pinnate, pinne more or less obliquely in- clined to the rachis and attached to the upper surface, apices acuminate and tapering or obtusely rounded, the base may be abruptly rounded and marked with a callosity near the point of attachment, or the pinne may be slightly and gradually narrowed towards the base, margins entire; veins parallel, but slightly divergent in the apical portion of each pinna.” While the foregoing characterization is quite general, greater precision seems undersirable in the present case. The basal callosity, a feature emphasized in most definitions, is a character the determination of which is often exceedingly difficult in the best of fossil material, and, of course, impossible in fragments of pinne which lack the base. Although Fontaine and Ward have described seven species of Zamites from the Potomac Group, this proves to be much too large a number, only two species being recognized in the present work. ‘These; while not common, are found at various horizons, always de- tached, however, and generally fragmentary, so that their distinctness from pinne of Podozamites is often determined with difficulty. The genus has a recorded range from the Triassic to the Oligocene, with many species in the Mesozoic, and while all of the species are not congeneric botanically, they are all doubtless referable to the Cycad- ophyte. *Bornemann, Ueber organische Reste Lettenkohlen Gruppe Thiiringens, 1856, p. 54. 4Saporta, Pl. jurass., tome ii, 1875, p. 84. ® Schimper, Pal. Végét., tome ii, 1870, p. 151. * Schenk, in Zittel, Handbuch, 1890, p. 218. 5 Seward, Wealden FL, pt. ii, 1895, p. 75. MARYLAND GEOLOGIOAL SURVEY 345 ZAMITES TENUINERVIS Fontaine Plate LIV, Figs. 1-5 Zamites tenuinervis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 171, pl. Ixvii, fig. 1; pl. lxix, fig. 2; pl. Ixx, fig. 1; pl. Ixxv, fig. 3; pl. Ixxvi, fig. 7; pl. xxviii, fig. 6; pl. lxxxiv, fig. 7. Zamites distantinervis Fontaine, 1890, loc. cit., p. 172, pl. Ixxxiii, fig. 4. Zamites subfalcatus Fontaine, 1890, loc. cit., p. 173, pl. Ixxxiv, fig. 13; -pl. lxxxv, fig. 3. ; Zamites tenuinervis Fontaine, 1893, Proc. U. S. Nat. Museum, vol. xvi, p. 267, pl. xxxvii, figs. 3, 4; pl. xxxviii, figs. 1, 2. Zamia washingtoniana Ward, 1895, 15th Ann. Rept. U. S. Geol. Survey, p. 350, pl. ii, fig. 6. Zamites tenuinervis Penhallow, 1902, Trans. Roy. Soc., Can., series ii, vol. viii, sec. iv, p. 42. , Zamites tenuinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xviii, 1905, pp. 257, 548 (?), pl. Ixviii, figs. 2, 3 (non p. 528). Zamia washingtoniana Fontaine, 1906, in Ward, loc. cit., p. 503 (pars), pl. exi, fig. 1 (non fig. 2). Podozamites distantinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 573 (non balance of citations). Description —Pinne always found detached, very long and relatively narrow, somewhat falcate. Apex not preserved in the Maryland or Virginia material. In a specimen from the Glen Rose beds of Texas, identified as this species by Fontaine, an obtusely rounded tip with con- vergent veins is shown. Base inequilateral, narrowed, and abruptly rounded, somewhat variable. Length presumably 20 em. or more, of the longest fragments preserved one is 15.5 cm. without showing the extreme base or any evidence of apical narrowing, while another rather obscure specimen, also lacking the extreme base or apex, is 20.5 cm. in length. Width from 1.2cm. to 2.3cem., averaging about 2cm. Veins parallel throughout most of their length, numerous, forked at their extreme base. Texture coriaceous: This species is rather common in the Potomac Group, being espe- cially abundant in the Patuxent formation at Fredericksburg, Virginia, and in the Glen Rose beds of Texas. All of the specimens are detached . . . \ . . and more or less fragmentary. Their distinctness from Podozamites is not conclusive, although a number seem to show evidence of a basal callosity, and altogether lack the contracted and more or less elongated 346 SYSTEMATIC PALEONTOLOGY peduncle of Podozamites distantinervis Fontaine, with which they are most closely comparable, There is some variability with respect ms closeness or remoteness of the veins and in the character of the base in the various specimens which the writer refers to this species but these variations are no greater than are shown among the specimens which the original describer referred to the type. For example, some of the specimens show a base which is slightly subcordate, while in the specimen which Ward made the type of Zamia washingtoniana, it is rather gradually narrowed, but no more so than in some of the Glen Rose specimens which Fontaine referred to Zamites tenuinervis, Again the typical forms of the latter have rather close-set fine veins, while the poorly preserved specimens with more remote veins but found associated with the others, were made the type of Zamites distantinervis Fontaine, although the veins are no more re- mote than in the Glen Rose specimens which the same author refers to Zamites tenuinervis. In reviewing all of the material it is seen that these minor variations and the variations in calibre of the veins due to the state of preservation are not of specific value, and it is found im- possible to frame any definitions which will permit the segregation of these various forms. The cone which Ward figures from the Patapsco formation as the cone of this species, while superficially suggesting a small Zamia cone, is undoubtedly a Sequota cone and not that of a species of Zamites. Zamites tenuinervis occurs in the Patuxent and Patapsco formations in the Maryland-Virginia area, but itis especially characteristic of the Patuxent. Elsewhere it occurs with considerable frequency in the Glen Rose beds of Texas. It is also reported from both the Knoxville and the Horsetown beds of California and from the Lower Cretaceous of the Queen Charlotte Islands. It shows a striking resemblance amounting almost to identity to Zamites Carruthersi Seward,’ from the English Wealden. A number of preparations were made for the purpose of observing the outlines of the epidermal cells and the stomata; but these all proved 4 1Seward, Wealden FI, pt. ii, 1895, p. 86, pl. vi, figs. 2-4. MARYLAND GEOLOGICAL SURVEY 347 unsuccessful, because of the granular nature of the lignite due to the advanced stage of decay reached by the pinnules before preservation. Occurrence-—PatuxENT Formation. Fredericksburg, Kankeys, Dutch Gap, Virginia. “Parapsco Formation. Mt. Vernon, Dumfries Landing, Widewater, Virginia; Gray’s Hill, Vinegar Hill, Stump Neck, Maryland. Collection—U. 8S. National Museum. ZAMITES CRASSINERVIS Fontaine Plate LIV, Fig. 6 Zamites crassinervis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, '-p, 172, pl. Ixix, fig. 4; pl. lxxxiii, fig. 3. Zamites ovalis Fontaine, 1890; Mon. U. S. Geol. Surv., vol. xv, 1889 (pars), p. 173, pl. Ixxxv, fig. 4; pl. elxx, fig. 3. Zamites sp., Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 173, pl. Ixxxiv, fig. 12. Zamites crassinervis Penhallow, 1902, Trans. Roy. Soc., Can., series ii, vol. vii, sec. iv, p. 41. Description —* Leaves broadly elliptical, short, acute, abruptly uar- rowed at base and attached by a callosity; nerves simple or forking at the very base, very strong, distant, parallel to near the apex, where they are more crowded.”—Fontaine, 1890. This species is not well marked and is unimportant and rare. Were it not for the indications of a callosity the writer would be inclined to refer these forms to Podozamites distantinervis Fontaine, which they greatly suggest. It has been recorded by Penhallow from the Cretaceous of Alliford Bay, Queen Charlotte Islands, but little reliance can be placed in the identification. Occurrence—PaTuxENT Formation. Fredericksburg, Dutch Gap, Potomac Run, Kankeys, Virginia. Collection.—U. S. National Museum. Genus CTENOPSIS gen, nov. Fronds pinnate, of large size. Pinne inserted latterly on a stout rachis, the angle of insertion dependent upon the proximal, distal or 348 SysTEMATIC PALEONTOLOGY intermediate position of the pinne, linear in outline. Apex unknown, analogy would suggest that it was obtuse. Base slightly enlarged above and decurrent below, two adjacent segments subtending a rounded, parallel-sided sinus, the width of the sinus being about half that of a segment. Texture coriaceous. The veins branch from the rachis at regular intervals at acute, approximately parallel angles, bending outward almost immediately and usually forking, the subordinate veins running close together, and parallel. The members of a single pair are about 0.333 mm. apart, while the space between each pair is about 1mm. Occasionally some of the veins fork again some distance from the rachis the branches running parallel with the remaining veins. The veins are slender and sharply defined when seen on specimens show- ing the lower surface of the fronds or on impressions of the lower surface, but they appear as a single flat band on impressions of the upper surface. With the genera Ctenis, Ctenidium, Ctenopteris, Ctenozamites and Cienophyllum already in the field it might seem unnecessary to propose a new genus for the fronds of this general type, and yet the Potomac species cannot be forced into any of these genera without unduly extend- ing their limits. Described originally as a species of Clenophyllum it differs from that genus in the character of the venation which is strictly simple and parallel in the latter. Ctenophyllum is moreover an older Mesozoic genus first known in the Triassic and culminating in the middle Jurassic. The type and the bulk of the species are late Triassic and none are known above the Oolite. The form in hand greatly resembles Ctenis in habit but the veins as far as observed do not anastomose as in that genus. The genera Ctenidium and Ctenopteris are quite different from the present genus in all of their characters, as is Ctenozamites. The two latter genera are bi- or tripinnate and the former has simple veins. Cienopsis may be looked upon as a gerontic type embracing some of the characters of both Ctenis and Ctenophyllum and representing one of the last authentic occurrences of this general type of cycad frond. While the foregoing discussion was going through the press, Seward described a new frond genus from the Jurassic of Scotland as Pseu- MaryYLanp GroLogicaL SURVEY 349 doctenis.. This is in many respects very close, if not identical, with Ctenopsis, and if the former can be shown to have the double vascular strands in the pinnules such as characterize the latter genus, the term Ctenopsis will possibly have to be abandoned. CTENOPSIS LATIFOLIA (Fontaine) Plate LV, Figs. 1, 2 Ctenophyllum latifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 175, pl. Ixviil, figs. 2, 3. Podozamites grandifolius Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 180, pl. lxxxii, fig. 2; pl. Ixxxiii, fig. 5 (non other references under this name). £ Ctenophyllum latifolium Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 255, pl. Ixvii, fig. 10. Description.—Frond very large and wide-spreading; length of pinne not disclosed, width in the same region of the frond variable, ranging from 27 mm. to 35 mm.; pinnules alternate, going off in the lower part of the leaf at a large angle, in the upper portion becoming much more oblique, attached by the entire width of the widened base, which is decurrent and meets the expanded base of the adjacent pinnules, forming a broad rounded sinus; those of the upper portion of the frond united more and more, all curved slightly upward toward the summit of the frond; tips of the pinne, not seen; veins slender, going off obliquely at their insertion in the lower and middle portions of the lower pinnules, but nearly at right angles in the upper portions, and all turning strongly outward to enter the pinnules; the veins fork usually at their insertion; oceasionally but rarely they fork farther from the rachis. These magnificent cycad fronds are extremely rare, although it is by no means certain that the plant which bore them was equally rare in the earlier Potomac flora. A large part of the frond is said to have been 1Seward, The Jurassic Flora of Sutherland, Trans. Roy. Soc., Edinb., vol. xvii, pt. iv, 1911, p. 691, pl. iv, figs. 62, 67, 69; pl. vii, figs. 11, 12, 17; pl. viii, fig. 32; pl. x, fig. 45. See particularly pl. vii, fig. 62, and pl. x, fig. 45, of Pseudoctenis lathiensis Seward. 350 Systematic PALEONTOLOGY uncovered in the quarry at Fredericksburg, and to have had the appear- ance and dimensions as shown in Professor Fontaine’s Fig. 2, cited above. This was unfortunately completely broken up in getting it out, the best -of the remaining fragments being that shown in fig: 1 of the present work. This shows the upper surface of the frond and emphasizes its coria- ceous texture. As previously stated, the pairs of veins appear as a single flat vein in this specimen. Fig. 2 of the present work shows an impres- sion of the under surface of a frond of somewhat smaller size and brings out clearly the slender, double veins of this species. This same form has been recorded (loc. cit.) from the Horsetown beds in California but the identification is based on rather uncertain material which, however, may well be identical with the Virginia form. The fragments from Virginia which were described by Professor Fontaine as Podozamites grandifolius are obviously referable to this species with which they are identical in size, texture, and in the peculiar double veins. They represent somewhat distorted fragments of detached pinnules. The supposed contracted base shown in the fore- going author’s fig. 5 is entirely fanciful. Other remains subsequently referred to this species* are of doubtful value. Occurrence.—PATUXENT Formation. Fredericksburg, Potomac Run, Virginia. Collection.—U. 8. National Museum. | . Genus CTENOPTERIS Saporta [Pal. Franc., t. i, 1873, p. 351 (Brongn. MSS.) ] This genus was established by Saporta in 1873 with the Filicites cycadea of Brongniart,” a Jurassic species, as the type. He charac- terized it as follows: “ Frons pinnata vel bi-tripinnata, pinne elongato-lineares pinnatiparti- tae basi exappendiculatae, pinnulae basi tota adnatae decurrentes inter se liberae versus apicem pinnarum plus minusve confluentes, brevi omnes * Fontaine, Mon. U. S. Geol. Surv., vol. xlviii, 1906, p. 167, pl. xliv, fig. 1. * Brongn., Hist., Végét. Foss., 1828, p. 387, pl. exxix, figs. 2, 3. MaryYLAND GEOLOGIOAL SURVEY 351 costa exorientes simplices furcatique divergentes, nervo medio nullo, nervulis mediis dense quandoque fasciculatis; fructificatio ignota.” The Potomac species are bi- or tripinnate with broadly linear-lanceo- late pinne of thick texture, with entire or toothed margins. The botanical position of this genus has never been definitely settled. Saporta has called attention to its resemblance to the Odontopteris forms of the Paleozoic and to the Oolitic genus Dichopteris of Zigno. Schimper makes it the basis for his filicinean genus Cycadopteris. Nathorst pro- posed the term Ctenozamites for remains of this sort and Seward origi- nally referred the English Oolitic material to Ptilozamites. While Fontaine regarded the Potomac species as ferns it seems very probable in view of the general habit of the fronds and in the absence of the fructi- fication characters that they are fronds of cycadophytes and they are so considered in the present work. As has been repeatedly pointed out, the modern cycad genus Bowenia furnishes an analogy among recent cycads and when we recall the probable diversity of the Mesozoic cycadophytes and their close relationship with the ferns, and particularly their filiation with forms with the fern-like foliage of the Paleozoic Pteridospermato- phytes, to which group at least some of the Odontopterids belong, there can be little objection raised to such a reference on the basis of frond characters. The genus Ctenopteris is mainly Jurassic, originating as far as the present records show in the Lias, and being especially well developed in the Oolites. Besides the three Potomac species to which the writer has reduced the six species of Fontaine, Saporta has described a Neocomian species from the Portuguese rocks and Penhallow another from the Cretaceous of Vancouver Island. In addition we have the closely allied cycadaceous genus Ctenidium Heer with two species in the Neocomian and Cenomanian of Portugal. The Potomac species, which in many respects suggest the genus Zamiopsis of Fontaine, are confined to the Patuxent and Arundel for- mations and are abundant in the older deposits at Fredericksburg, Virginia. 23 352 SysTEMATIC PALEONTOLOGY CTENOPTERIS INSIGNIS Fontaine Ctenopteris insignis Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 156, pl. lxi, figs. 4, 5; pl. Ixii, fig. 1; pl. Ixiii, figs. 1, 2. Ctenopteris virginiensis Font., 1890, Ibid., p. 157, pl. Ixii, fig. 4; pl. Ixv, fig. 1; pl. Ixvi, fig. 4. Ctenopteris minor Font., 1890, Ibid., pl. lxvii, fig. 3. Ctenopteris insignis Font., 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 521, pl. cxii, fig. 7. Zamiopsis insignis Font., 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 525, pl. exiii, figs. 4, 5. Description —* Frond large, arborescent, bipinnate or tripinnate; principal rachis very strong, striate; ultimate pinne with strong, rigid rachises, alternate, terminating in a lobed segment, the pinnules passing into lobes more or less united toward the ends of the ultimate pinne; pinnules thick and leathery, those of the lower and middle portions of the pinnae attached by the entire base, slightly decurrent, separate, cut away obliquely above, alternate to subopposite, gradually diminishing towards the summit of the pinne in size and depth of toothing, not sensibly narrowed at base, oblong-acute, curved slightly forward, terminating in a large ovate to subtriangular acute tooth. The pin- nules usually show two acute or spinous teeth on each side, a couple near the base, and a second couple near or at the summit of the pinnule, the associated members of the couples being opposite or subopposite. Sometimes there is an additional tooth on the posterior margin below the upper one, and sometimes the terminal tooth is enlarged to an oblong lobe, which is slightly notched; nerves several, departing separ- ately from the principal rachis along the entire width of the base of the pinnule, the outermost ones once forking and curving outwards, the inner ones forking deeply several times and slightly diverging flabel- lately, the ultimate branches nearly or quite parallel, long, and slender.” —Fontaine, 1890. The only satisfactory specimens of this plant come from Fredericks- burg, where it is not uncommon, but usually rather indistinctly pre- served. The additional occurrences are based on small fragments. MARYLAND GEOLOGICAL SURVEY 353 Considerable variability is shown among the various forms but not enough to warrant specific distinctions. The specimen named Clenopteris minor by Fontaine is simply a small form of the type as the latter author suspected. The marginal toothing is quite a variable feature on a single specimen of any size, and the form named Ctenopteris virginien- sis by Fontaine shows a variation in the venation in the direction of the genus Scleropteris, the veins being apparently aggregated into two bundles at their insertion on the rachis, although this feature is far from clear on the specimens, the coriaceous nature of the pinnules rendering the venation indistinct and quite unlike the diagrammatical figures of these forms which were originally published. Occurrence——PatTuxEent Formation. Fredericksburg, and near Po- tomac Run, Virginia. ArunpreL Formation. Langdon, District of Columbia. Collection.—_U. S. National Museum. CTENOPTERIS ANGUSTIFOLIA Fontaine Ctenopteris angustifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 159, pl. Ixv, fig. 2; pl. Ixvii, fig. 4. Ctenopteris angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 510. Description —“ Frond unknown; ultimate pinne long, with rather stout rachises, pinnules linear or narrowly oblong, in proportion to width quite long, slightly curved forwards, separate to the base, or united to form a wing on the rachis of the pinne, cut away obliquely on the upper side at base, and slightly decurrent on the lower side, attached by the entire base, terminated by from one to three acute spinous teeth, and having a varying number of the same placed irregularly on both margins. The nerves proceed from the rachis at different points along the entire base of the pinnules; the outer ones simple or forking once, the central ones forking several times, the ultimate branches being long, slender, and slightly diverging.”—Fontaine, 1890. 354 SYSTEMATIC PALEONTOLOGY This species which is based upon infrequent and insufficient material may simply be a variant of the common Ctenopteris insignis from which it shows but minor differences. Occurrence—PatuxeNt Formation. Near Potomac Run, Chinka- pin Hollow (?), Virginia. Collection —U. S. National Museum. CTENOPTERIS LONGIFOLIA Fontaine Ctenopteris longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 159, pl. Ixvii, fig. 5. Description.—* Frond unknown; rachis of the ultimate pinne very broad, but not apparently very woody; pinnules placed very remotely, opposite, going off obliquely, very long, linear, narrowed gradually and slightly towards the base and slightly decurrent, tips not seen; nerves not well made out, but apparently several, departing independently from the rachis and forking near the base; the branches, so far as seen, simple, and nearly parallel.”—-Fontaine, 1890. This species was based upon the single specimen figured, which is the only one ever discovered, hence little can be added to the foregoing diagnosis. It seems probable that it is simply a variant of one of the other species of Ctenopteris which occur in the same layers, as for example Ctenopteris angustifolia. Occurrence.—PaTUXENT Formation. Fredericksburg, Virginia. Collection.—U. S. National Museum. Genus ZAMIOPSIS Fontaine [Mon. U. S. Geol. Surv., vol. xv, 1890, p. 160] This genus was established by Fontaine for certain supposed fern-like remains from the older Potomac which were characterized as follows: “ Fronds large, bipinnate to tripinnatifid; leaf-substance leathery and thick, covered with a dense, durable epidermis; rachises strong, rigid, and keeled on the lower surface, often with ridges or raised margins on MaryLanp GroLogicaL SURVEY 355 the upper surface; penultimate pinnx very long, ultimate pinne or pin- nules usually closely placed, narrowed to the base, mostly linear-lanceo- late or oblong-lanceolate, the: lower ones generally cut obliquely into pinnules which are denticulate, but pass above into denticulate or spinous teeth and terminate in two or more spinous teeth; nerves of the pinnules and lobes mostly composed of a midnerve which goes off very obliquely and curves strongly outwards, sending off obliquely and alternately lateral branches, which are forked or simple and curve upwards towards the summit of the segment; in the lobes and teeth the lateral nerves go off very obliquely and fork once or twice, having very long ultimate branches; nerves, although fine, very distinct.” These plants are closely related to the geaus Cienopteris and possibly they should be included in that genus. They differ in having the pinne narrowed at the base, correlated with which the vascular strands are usually gathered into a single vein. Although Professor Fontaine compared these forms with the cycads he decided that the fern-like char- acters predominated. In the present treatment they are referred to the cycadophytes. The latter on a priori grounds would be expected to have included forms with branched fronds and other fern-like characters such as are possessed by Zamiopsis and Ctenopteris. It may be noted also that this is the habit in the modern genus Bowenia: That the toothed pinnules not only are present in a number of modern cycad genera, but are especially well developed in Encephalartos: And that the venation characters are very like those of the recent cycad-genus Stangeria. With a single doubtful éxception the genus is confined to the Patuxent formation, and with but a single doubtful occurrence it is confined to the Virginia area. ZAMIOPSIS DENTATA (Fontaine) Plate LVI, Figs. 1, 2 Scleropteris dentata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 153, pl. xiii, figs. 3, 4. Zamiopsis pinnatifida Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 161, pl. Ixi, fig. 7; pl. lxii, fig. 5; pl. lxiv, fig. 2; pl. Ixvii, fig. 2. 356 SYSTEMATIC PALEONTOLOGY Zamiopsis insignis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 162, pl. Ixii, fig. 3; pl. lxiv, figs. 1, 3; pl. Ixv, figs. 4-6; pl. lxvi, fig. 2; pl. lxvii, fig. 7. Zamiopsis longipennis Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 164, pl. lxi, fig. 8. Zamiopsis insignis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 511 (?), 517 (non p. 525, pl. exiii, figs. 4, 5, which is referred to Ctenopteris dentata). Description—Frond large, bipinnate or tripinnate, with keeled rachises. Pinnules ovate-lanceolate or somewhat falcate in outline, variously toothed or pinnatifid, depending upon their position on the frond, narrowed basally. The proximal ones are more or less pinnati- fid, at times being merely toothed, again the basal divisions may be long and narrow, suggesting Z4amiopsis laciniata. Ascending the frond the pinnules are less and less prominently toothed until they are of the type named by Professor Fontaine Zamiopsis longipennis. The ulti- mate form is that shown in some of the fragments which were named Scleropteria dentata. The character of the margin is very variable, all the above features being shown on a single frond. The midvein of the pinnules is very stout below, thinning rapidly and finally lost in repeated branching toward the apex. The laterals are long and slender, branch- ing from the midrib at a very acute angle and after ascending, curving outward, giving off one or more branches at a small angle, all being approximately parallel to the margin. The texture is very coriaceous and the venation is not prominent. No new material of this species at all comparable in extent with the type material has been collected in recent years and the latter is not well preserved at the present time because of its weathering. There are no adequate grounds for maintaining the several forms which the writer has combined to form this species, in fact their author suggested that his species longipennis might be an ultimate pinnule of insignis and that his species pinnatifida might also be a variety of this species, which is un- undoubtedly the case. There is some question about the exact horizon as well as the identity of the specimens from Chinkapin Hollow referred to this species by Professor Fontaine in 1906. Most of the species from Chinkapin MarYLAND GEOLOGICAL SURVEY 357 Hollow appear to be Patapsco forms and it is possible that Zamiopsis insignis may have continued after the close of the Patuxent. One feature worthy of comment is the venation. The laterals are not gathered together in systems with a main trunk to each segment of the pinnule as previously described and figured, but they branch more uniformly and fork less frequently and pursue approximately parallel courses, suggesting greatly the venation of the modern cycad-genus Stangeria. Occurrence.—PatuxENt Formation. Fredericksburg, Chinkapin Hollow (?), Virginia; New Reservoir (?), District of Columbia. Collection.—U. 8. National Museum. ZAMIOPSIS PETIOLATA Fontaine Zamiopsis petiolata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 166, pl. Ixvi, fig. 3. Description Frond bipinnate or tripinnate, principal rachis with a strong wing; primary pinna terminating abruptly in a large incised pinnule similar to those lower down; pinnules petiolate, attached by the midnerve, prolonged into a stout petiole, alternate, cut obliquely into oblong or subelliptical obtuse pinnules, in the lower part of the ultimate pinnae turned outwards. These graduate in the upper parts of the same into lobes and teeth of the same general character. The summit of the ultimate pinna is a broad oblong segment, ending in several shallow subacute teeth formed by the union of the lobes at the summit; the ulti- mate pinne in passing towards the summit of the penultimate ones diminish much in size, the pinnules and lobes passing finally into teeth; lateral nerves in each pinnule and lobe consisting of a nerve-bundle . which goes off very obliquely from a point near the lower end of the pin- nule or lobe, branching near the insertion, and curving out to enter the pinnule or lobe, the branches forking again once or twice, with the ulti- mate nerves very long and slender, owing to their deep forking.” —Fontainé, 1890. This rare plant represents a development of the Zamiopsis dentata type in the direction of greater subdivision of the pinne and the forma- 358 SysTEMATIC PALEONTOLOGY tion of a petiole. It is very doubtfully distinct from that type, with which it is also associated. It is not at all certain that the winged rachis is not a feature due to compression during fossilization. Occurrence. —PATUXENT Formation. Fredericksburg, Virginia. Collection.—U. S. National Museum. ZAMIOPSIS LACINIATA Fontaine Zamiopsis laciniata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 164, pl. Ixvi, figs. 1, 5-8. Description —“ Frond very large and wide-spreading, probably arbores- cent; ultimate pinne alternate, the lower ones very long, rapidly diminishing in length and size in ascending towards the summit of the principal pinne, having a distinctly winged rachis, and terminating in a variously shaped segment formed of united pinnules or lobes, usually three in number; pinnules very’variable in size and shape, mostly long, ribbon-shaped, slightly narrowed to the base and attached by the entire base, decurrent, and united to form a wing, cut very obliquely into a few lobes of varying depth, which are elongate-oblong or narrowly ovate in shape, and nearly always placed on the posterior margin of the pinnule. The lobes toward the summit of the pinnules pass some- times into acute triangular teeth, which are turned outwards. The pinnules at the summit of the ultimate pinne pass into more or less united lobes, which vary a good deal in shape, being somewhat much narrowed and even wedge-shaped at base, and incised into a varying number of irregularly shaped teeth; nerves of the pinnules departing from a short mother nerve at the base of the pinnules, forming three branches, these diverging slightly in a flabellate manner; branches very long, slender, but distinct, outer branches simple or once or twice forked, the inner one forking several times and approaching the character of a midnerve; leaf-substance thick and leathery.”—Fontaine, 1890. This plant is of rare occurrence and combines the features of the genera Cienopteris Saporta, Ctenidium Heer, and Scleropteris Saporta. It also suggests the latter author’s genus Stenopteris. It is confined to the lowermost Potomac in the Virginia area and has not been dis- covered in Maryland. MaRYLAND GEOLOGICAL SURVEY 359 The existing genus Bowenia has analogously divided fronds, while a number ef existing species of Hncephalartos have similarly toothed pinnules. Occurrence.—Paruxent Formation. Fredericksburg, Virginia. Collection —U. S. National Museum. Genus NILSONIA Brongniart [Ann. Sci. Nat., tome iv, 1825, p. 218] This genus was founded by Brongniart for certain remains from the Rhetic of Sweden which had been recorded and figured by Nilsson in 1820 who regarded them as fern remains. In the Prodrome the diagnosis is as follows: “ Feuilles pinnées; pinnules rapprochées, oblongues, plus ou moins alongées, arrondies au sommet, adhérentes au rachis par toute la largeur de leur base, 4 nervures paralléles, dont quelques-unes sont beaucoup plus marquées.” + The genus was regarded by Brongniart as referable to the Cycadales, a view generally accepted by subsequent workers, although Schenk’ in 1867, on the basis of supposed sori on some german specimens, referred it to the Filicales, in which he was at first followed by Schimper * and more recently by Solms-Laubach.* The genus has also been ably discussed by Saporta, Nathorst, Seward, and others, Nathorst in particular having shown that the two kinds of veins.supposed to occur together were due to slight folds in the lamina due to pressure, maceration, or the creep of the enclosing strata. He characterizes the veins as equal and simple, and emphasizes the insertion of the lamina on the upper surface of the rachis, suggesting that Schenk’s supposed sori are fungal or stomatal in their nature.” 1Brongniart, Prodrome, 1828, p. 95. 2 Schenk, Die fossile Flora Grenzschichten Keupers u. Lias Frankens, 1867, p. 124, 2? Schimper, Pal. Végét., tome i, 1869, p. 488. + Solms-Laubach, Fossil, Botany, 1891, p. 139. 5 See Nathorst, Ueber die gattung Nilssonia Brongn., Kong]. Svenska Vet. Akad. Handl., Band xliii, 1909, No. 12. 360 SYSTEMATIC PALEONTOLOGY The genus may be redefined in the following terms: Frond coria- ceous, elongate-lanceolate in outline, entire or commonly more or less deeply pinnatifid by being split, usually to the rachis, into a number of more or less irregular segments which are contiguous, usually broad and truncate. Lamina attached to the upper surface of the rachis, the simple and parallel, equal, lateral veins running almost or quite to the median line. In material showing only the under surface of the fronds, the stout midrib is prominent and unsegmented specimens are scarcely distinguishable from Tniopteris and allied forms, while the segmented varieties approach Anomozamites or even some species of Pterophyllum in appearance. The genus Nilsonia appears in the Triassic and is particularly a Rhetic and Oolitic type. A number of undoubted species occur, how- ever, in the Lower Cretaceous, no less than seven different species having been recorded from the Lakota, Kootanie, and Shasta deposits. The Neocomian of Japan furnishes two or three species, while the wide- spread Nilsonia schaumburgensis (Dunker) Nathorst, occurs very abun- dantly at anumber of European Wealden localities. The Upper Cretaceous shows a species in the Atane beds of Greenland and one in the Cenomanian of Bohemia, while several supposed species have been recorded from Tertiary strata. There are two species in the Potomac Group, a lanceolate unsegmented form variously described by Fontaine as Angiopteridium and Sapindopsis and the large and elegant form which this author describes as two species of Platypterygium. The latter term was proposed by Schimper, in 1880, as a subgenus of Anomozamites for very large forms of that type. It was subsequently used as a genus by Feistmantel and Fontaine, although this usage seems unwarranted, especially since the Platyptery- gium forms of Anomozamites are all confined to much older horizons, and the Potomac forms agree in all essential characters with Nilsonia, a relationship suggested by Seward, in 1900, ofter examining the material in the U. 8. National Museum. As illustrated by Fontaine, the rachis is represented as very wide and the opposite segments are far apart. That the midrib was not wide and flat in life, but prominent MARYLAND GEOLOGICAL SURVEY 361 below and not out of proportion to the size of the fronds is shown by a most casual examination of the considerably macerated and much flattened specimens, and is clearly indicated by the specimens photo- graphically reproduced on the accompanying plates. In collections from the Cretaceous of Japan, Stopes has been fortu- nate enough to obtain petrified material of the leaves of Nilsonia orientalis Heer which is described at length.” This species is one of the Teeniopteris-like species, Seward in his Wealden flora* having suggested that it was a Teniopteris, and Nathorst * having proposed that the closely allied Nilsonia tenuinervis Nathorst would have its botanical affinity more clearly indicated by the name Nilsoniopteris. It is interesting, therefore, to find that the internal anatomy of Nilsonia orientalis Heer is clearly gymnospermous rather than fern-like and exactly of the type which might be regarded as primitively cycadean. & NILSONIA OREGONENSIS (Fontaine) Berry Angiopteridium strictinerve Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, pp. 240, 511, pl. Ixvi, figs. 5-7; pl. ex, fig. 12 (non Font., 1890). Sapindopsis oregonensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 268, pl. Ixix, figs. 15-17. Nilsonia oregonensis Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 637. Description Frond simple, unsegmented in all the specimens col- lected, lanceolate in outline, with equally pointed apex and base. Length apparently about 7 cm. to 15 cm. and greatest width, which is midway between the apex and the base, 1.2 em. to 1.6 cm. Texture coriaceous. Rachis stout, prominent below. Lateral veins close and parallel, the great majority simple but an occasional vein forking dichotomously. Angle of divergence farge, varying from 55° in the apical part of the frond to 85° in the median and basal portions. 1 Stopes, Ann. of Botany, vol. xxiv, 1910, pp. 389-393, tf. 1, pl. xxvi. 2 Seward, Wealden F1., pt. i, 1894, p. 123. - 3 Nathorst, Kung]. Svenska Vetens Akad. Handl., Band xliii, 1909, p. 29. 362 SYSTEMATIC PALEONTOLOGY This species is based upon considerable incomplete material from widely separated localities which afforded the basis for two different ~ species of Fontaine, but which seem to be identical and markedly different from the types to which they were referred. The forms referred to Angiopteridium strictinerve are from Virginia and Cali- fornia while those described as a new species of Sapindopsis, which genus they do not resemble in the remotest degree, are from California. The former are quite different from the type of that species, being smaller and less elongate, with closer, mostly simple veins, and with the rachis prominent below and masked above by the lamina of the frond. The latter correspond with the others in outline and venation, differing in outline, venation, and in the character of the rachis from Sapindopsis. The present species, which is confined to the Potomac Group and the Shasta of California, where it occurs in both the Knoxville and the Horsetown beds, is suggestive of the species from the Neocomian of Japan which Yokoyama” identifies as Nilsonia Johnstrupi Heer. It may also be compared with the rather widespread Wealden species Nasonia schaumburgensis (Dunker) Nathorst, which has also been recorded from Japan and from the Kootanie of Montana. Occurrence—PatUxENT Formation (?). Chinkapin Hollow, Vir- ginia. Collection.—U. 8. National Museum. NILSONIA DENSINERVE (Fontaine) Berry Plates LVII, LVIII Platypterigium densinerve Fontaine, 1890, Mon. U. 8S. Geol. Survey, vol. xv, 1889, p. 169, pl. xxx, fig. 8; pl. xxxi, figs. 1-4; pl. xxxii, figs. 1, 2; pl. xxxilii, fig. 1; pl. xxxiv, fig. 1; pl. xxxv, figs. 1, 2. Platypterigium Rogersianum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 171, pl. xxxi, fig. 2; pl. xxxiii, fig. 2; pl. xxxiv, fig. 2. Platypterygium densinerve Fontaine, 1906, in Ward, Mon. U. 8. Geol. Survey, vol. xlviii, 1905, p. 521, pl. exii, fig. 8. Nilsonia densinerve Berry, 1910, Proc. U. 8. Natl. Mus., vol. xxxviii, p. 638. *Yokoyama, Jour. Imp. Coll. Sci., Japan, vol. vii, 1895, p. 226, pl. xxv, figs. 1-4, MARYLAND GEOLOGICAL SURVEY 363 Description.—Fronds large, upwards of 50 cm. to 70 cm. in length by 15 cm. to 18 ecm. in greatest width, averaging about 12 cm., either entire or more often irregularly divided into rectangular or subrhombic segments, at times somewhat rounded basally. Texture coriaceous. Rachis stout, prominent below, more or less flattened during fossiliza- tion. Laterals of small calibre, close, 4 to 1 mm. apart, parallel, in- variably simple and nearly straight, diverging at an angle in the neigh- borhood of 90°. This splendid species, presumably because of its large size, is repre- sented only by fragmentary specimens, both the apex and the base being missing. It is not at all common and is confined entirely to the Patuxent and Arundel formations in the Maryland-Virginia area. The specimens show some individual variations in the degree of segmentation, and a" a U, Fie. 11—Cross-sections of fronds of Nilsonia densinerve. a—showing method of fossilization of specimen shown on pl. Ivii, fig. 1, natural size. b—Diagrammatic cross-section of specimen shown on pl. lviii, fig. 1, natural size. strength and position of the lateral veins, the forms which served as a basis for Platypterygium Rogersianum of Fontaine being more robust but somewhat smaller than the others with veins somewhat larger in size and less closely placed, but the limits of variation are, nevertheless, quite restricted. = There can be but little doubt of their all belonging to a single species. The accompanying plates, which illustrate in an admirable manner the variation in appearance and manner of preservation of these fronds, are photographs of three of Fontaine’s figured specimens, which ones it will rest with the reader to discover among the figures cited (supra), the writer being wholly unable to determine. At first glance, the rachis 364 SYSTEMATIC PALEONTOLOGY appears to have been wide and ribbon-like, but this was not the case. The segments are inserted on the upper surface of the rachis in conform- ity with the generic diagnosis, and in one of the larger specimens (an impression on the reverse side of the specimen shown on pl. lvii), the lateral veins of opposite sides approach to within 1 mm. of each other, being separated by a slightly raised ridge. Below it is seen that the rachis is flattened, and during or since fossilization, small fragments of the inner margin of the segments overlying the rachis have flaked off, exposing more or less of the broadly flattened rachis below as is well shown on pl. lviii. Fig. 1 shows a diagrammatical cross-section of this frond. In pl. lvii, fig. 2, the appearance is somewhat different, due entirely to the process of fossilization. The right hand segments are in place, attached to the upper raised line of the rachis, which during fossilization, possibly by the creep of the strata before lithification, was laid over toward the left and flattened, the left hand segments being detached and superimposed upon the flattened rachis. Text-fig. lla is a diagram- matical cross-section across the base of this specimen. Remains very suggestive of this species, but in a more fragmentary condition, have been described by Nathorst from an unknown, probably Neocomian, locality in Japan as Macroteniopteris (?) marginata. Occurrence.—PaTUXENT Formation. Fredericksburg, Virginia. ARUNDEL Formation. Langdon, District of Columbia. Collection—U. S. National Museum. DICHOTOZAMITES gen. nov. Fronds dichotomously compound. Rachis relatively slender, keeled. Pinnules slender, linear, acuminate, ascending, with a markedly decur- rent base, attached laterally, alternate to opposite. Margins simple tending to be slightly inrolled dorsally. WVenation consisting of a single midvein to each pinnule, prominent below and slightly sunken above, * Nathorst, Beitr. z. Mesozoischen Fl. Japans, Denks. k. Akad. Wiss. Wien, Band lvii, 1890, p. 54, pl. vi, figs. 6, 6a. MARYLAND GEOLOGICAL SURVEY 365 which gives off at nearly right angles rather remote, short, simple secondary veins, which run direct to the margin. This genus is based on the forms which Professor Fontaine referred to Sequoia and which he compared with C'ycadites and certain existing species of Podocarpus as well as with the Triassic Tacites falcatus of Nathorst. The distichous phyllotaxy is decidedly against the reference of these forms to the Coniferales, for while many conifers have a distichous habit the phyllotaxy is cyclic or spiral. The attachment of the pinnules is also against a reference to the Coniferales, as is also the venation. The dichotomous frond-habit, while wanting in modern cycads, is in a measure paralleled by the bipinnate fronds of Bowenia and by numerous bipinnate Mesozoic cycadophytes. Finally in a group derived from the Paleozoic pteridosperms, the majority of which had highly decompound fronds, some of which like Odontopteris, which is probably a member of this phylum, had a dichotomous habit (cf. Odontopteris minor Brongniart), it would be more than anomalous if all of the Mesozoic forms had the foliar characters of the modern cycads and none retained any of the foliar characters of their Paleozoic ancestors. DicHoTOZAMITES CYcADOPSIS (Fontaine) Plate LX XVII, Figs. 2, 3 Sequoia cycadopsis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 248, pl. cxii, figs. 911; pl. cxiii, figs. 1-3. Sequoia cycadopsis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xviii, 1905, pp. 489, 533, pl. cix, fig. 11. Description.—Frond dichotomously compound with a slender keeled rachis. Pinnules slender, linear, acuminate, markedly decurrent, slightly curved. They are attached to the rachis laterally and are ascending, sub- tending an angle of about 22°. Length variable, averaging about 3 cm. The length and angle vary with the position on the frond and the arrange- ment is rather open and varies from alternate to opposite. Each pinnule has a midvein which is prominent below and sunken above. Secondaries branch from it at an angle of nearly 90°, and are 366 SYSTEMATIC PALEONTOLOGY rather remote, parallel, straight, and simple, running directly to the margin. The latter is entire and often slightly revolute giving the pinnules an acicular appearance. As preserved they range from 0.5 mm. to 1.75 mm. in width. The texture is coriaceous and the habit is strict and rigid. This plant while not common is far from rare in the Patapsco forma- tion to which it appears to be confined.t It is quite different from any fossil or recent plant known to the writer. It resembles somewhat the Jurassic Stenopteris desmomera Saporta* in form but it is decidedly different in venation. Superficial resemblances to various other described fossils might be pointed out, but they would be of slight value or interest. Occurrence-—Patapsco Formation. Mt. Vernon, near Brooke, Vir- ginia; Ft. Foote, Maryland. Collection. —U. 8. National Museum. Genus CYCADEOSPERMUM Saporta [Pl. Jurass., tome fi, 1875, p. 235] This genus was founded by Saporta, in 1875, for the reception of certain Jurassic seeds or ovules believed to be those of cycads, the type species being Cycadinocarpus hettangiensis Schimper from the infra Lias of Hettange. It received the following characterization: “Semina e carpophyllis distracta post maturationem in strata pervagata nune majora nunc plus minusve parvula, plerumque ovata ovatoque-oblonga haud raro compressione mutua angulosa extus levia vel longitudinaliter striata costataque, basi semper rotundiore insertionis cicatrice notata apice autem plus minusve attenuata.” Three other species were described at the same time, embracing forms previously named Cycadocarpus by Saporta, Carpolithes by Schenk, and Ulospermum by Pomel. 1Through the kindness of Dr. Arthur Hollick I learn that this or a closely allied form is present in his Cretaceous material from Alaska. ?Saporta, Plantes jurassique, tome i, 1873, p. 292, Atlas, pl. xxxii, figs. 1, 2; pl. xxxili, fig. 1. MaryLAND GEOLOGICAL SURVEY 367 When Professor Fontaine came to work up the Potomac flora he founded six new species of Cycadeospermum upon rather obscure remains of fruits or seeds from various localities in Virginia, and additional remains of a similar character have since been described by the same author from the Shasta formation of California, the Kootanie forma- tion of Montana, the Triassic of Pennsylvania, and the Jurassic of Oregon. In the flora of the Dakota Group, Professor Lesquereux referred two additional species of rather doubtful value to this genus which has come to be looked upon as a convenient form-genus for the reception of fruits or seeds which suggest a cycadean affinity, but about which no certainty can exist, since they have thus far failed to show internal structure and are all found detached, although at times asso- ciated in the same deposits with cycad-like fronds, as is the case with the Potomac species which follow. CYCADEOSPERMUM MARYLANDICUM sp. nov. Plate LXX'VII, Fig. 8 . Description —Fruits of medium size, 14 mm. to 15 mm. in length, 8 mm. to 9 mm. in width, and from 5 mm. to 6 mm. in thickness, ovate in outline, chalazal end broadly rounded, almost truncate, sides but slightly curved, approaching each other toward the micropylar end, which is not preserved in its entirety. Surface hard and shiny with faint longi- tudinal striw especially toward the upper end. Sides with a trace of different tissue, apparently the remains of the outer slightly fleshy layer of the integument, which is also the cause of the strie upon the surface of the testa. This species is based upon a single rather well preserved specimen which comes from the blue charcoal clay of Coffins’ Bank at Muirkirk. It is the most cycad-like of any of the fruits referred to this genus and is almost certainly the fruit of some one of the Maryland Potomac cycads. The entire outer integument was slightly fleshy and the inner one stony as in the modern members of this group. If the fossil be 24 368 SYSTEMATIC PALEONTOLOGY compared with well-dried seeds of a modern Zamia the resemblance is found to be very close. Occurrence.—ARUNDEL Formation. Muirkirk, Prince George’s County. Collection—U. 8. National Museum. CYOADEOSPERMUM OBOVATUM Fontaine Cycadeospermum obovatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 270, pl. cxxxv, fig. 13. Cycadeospermum obovatum Fontaine, 1906, in Ward, Ibid., vol. xlviii, pp. 485, 520, 528, 545, pl. evii, fig. 5. Description—Medium sized ovate-spatulate seed-like objects, 10 mm. to 12 mm. in length, by 6 mm. to 9 mm. in greatest width which is toward the obtusely rounded end; the opposite end is reduced to a narrow pointed neck. Surface smooth and shining, hard. This species, which was based upon the specimens from near Potomac Run, Virginia, has been found at a number of additional localities in Virginia and Maryland. Its reference to this genus is of doubtful propriety and it is quite suggestive of the seeds of various modern mem- bers of the Taxacez, so that the inference is raised whether it might not be related to Cephalotaxopsis or Nagetopsis of the Potomac flora. Occurrence.— ARUNDEL ForMaATION. Langdon, District of Columbia; German’s Iron Mine (?), Maryland. Patapsco Formation. Fort Foote, Maryland. Collection.—U. 8. National Museum. CYCADEOSPERMUM AcuTUM Fontaine Cycadeospermum acutum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 270, pl. cxxxv, fig. 12. Cycadeospermum acutum Fontaine, 1906, in Ward, Ibid., vol. xlviii, 1905, pp. 480, 535. Description —Seed small, oval, obtusely rounded at one end and markedly acute at the other, about 7 mm. in length by 6 mm. in greatest breadth. Surface smooth and firm. MARYLAND GEOLOGICAL SURVEY 369 This species was based upon rare specimens from near Potomac Run, Virginia, and a single specimen was afterward recorded from Alum Rock in that State. The Maryland occurrence is based upon Fontaine’s record of a single doubtful specimen, which the writer has been unable to find. The species is of doubtful value at best, and is included in the Maryland flora with some hesitation and for the sake of completeness. Occurrence-—PaTUXENT ForMATION. Potomac Run, Alum Rock, Virginia. ARUNDEL Formation. Muirkirk (?), Maryland. Collection —U. S. National Museum. CYCADEOSPERMUM ROTUNDATUM Fontaine Cycadeospermum rotundatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 271, pl. exxxvi, fig. 12. Cycadeospermum rotundatum Fontaine, 1893, Proc. U. S. Nat. Museum, vol. xvi, p. 279, pl. xliii, fig. 6. Cycadeospermum rotundatum Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 667, pl. clxii, fig. 19. Cycadeospermum rotundatum Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, pp. 280, 537. Description.—Small, nearly orbicular nut-like seeds, about 7 mm. in diameter. Surface smooth and hard. This species was based originally upon a single specimen found at Kankeys, Virginia, and afterward identified by the original describer from the Glen Rose beds of Texas and from the Oak Creek shales of the Black Hills, which now form a part of Darton’s Fuson formation. It is also doubtfully recorded from the Kootanie formation at Great Falls, Montana. While these widely removed remains are from nearly the same geo- logical horizon and are identical in appearance, little certainty can be felt as to their actual identity and this for the reason that spheri- cal seed-like remains, which it would be difficult to distinguish from this species, occur at a great variety of geological horizons and might apper- tain to plants of widely differing botanical affinities. Occurrence—PaTUXxENT Formation. Kankeys, Virginia. ARUNDEL Formation. Contee, Maryland. Collection—U. S. National Museum. 370 Systematic PALEONTOLOGY CYCADEOSPERMUM SPATULATUM Fontaine Cycadeospermum spatulatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 271, pl. exxxv, figs. 11, 21. Cycadeospermum ellipticum Fontaine, 1890, Ibid., fig. 19. Cycadeospermum ellipticum Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 520. Description—Seeds of considerable size, 15 mm. to 17 mm. in length by 12 mm. to 13 mm. in longest lateral diameter, nearly orbicular in outline, sometimes slightly truncated at one end and bluntly pointed at the other. Surface smooth and glossy. Apparently of a firm and durable consistency. This species is based on a number of specimens from near Dutch Gap Canal on the James River, Virginia, and upon rare occurrences of similar objects at Fredericksburg, and near Potomac Run, in the same State, and two specimens from Langdon, in the District of Columbia. Occurrence—PatuxENT Formation. Fredericksburg, Dutch Gap, Potomac Run, Virginia. ARruNDEL Formation. Langdon, District of Columbia. Collection —U. S. National Museum. Cass GYMNOSPE RMAE Order GIN KGOALES Family GINKGOACEAE Genus BAIERA Fr Braun [Flora, Neue Reihe, Jahrg. 24, 1841, p. 33] This genus was defined by Braun as follows: “Vene primarie frondis pluries dichotome; ven secundaria ac venule in areas hexa- gonales elongatas irregulariter confluentes ; Sporocarpia capsuleformia, ovalia pedunculata, ternata vel biternata.” ( 18438, p. 20.) The type was Baiera dichotoma from the Rhetic of Strullendorf, Bavaria. In Braun’s contribution to Miinsters Beitrage zur Petrefacten- kunde, which is often cited as the original place of publication, as for example in Seward’s Jurassic Flora, five species are referred to this MARYLAND GEOLOGICAL SURVEY 371 genus, one other being from the Rhetic, and the balance from somewhat later, Jurassic horizons. Braun considered these forms referable to the ferns and compares them with the Marsiliacew. In this he was followed by Schimper (1869) ; and Schenk (1871), who include them in the family Neuropteride. Both authors, however, subsequently placed the genus in the Gymnosperme (In Zittel’s Handbuch, 1890), where they are commonly considered to belong at the present time as members of the order Ginkgoales (Pontonié, 1889, Saporta, 1879, Solms-Laubach, 1891, Zeiller, 1900, etc.). Certainly the sporophylls and fruits described by Schenk, Heer and Leuthardt, in some of the older Mesozoic forms are conclusive evidence of their gymnospermous nature, especially when considered in connection with the multipartite and undoubted true Gink- goes of the later Jurassic and the well-known tendency of the leaves of the modern Ginkgo in localized situations (seedlings, shoots, and grafts), to revert to a very Baiera-like form. Seward’ states that it is not improbable that some of the species of Baiera are best compared with certain recent ferns such as Actinopteris radiata Link and Schizea dichotoma Sw., or Schizea elegans Sw., and in this connection (Wealden FI., pt. ii, 1895, p. 5, pl. xiii, figs. 1, 2), he points out the considerable resemblance to Baiera shown by the fronds of Macrozamia heteromera Moore var. Narrabri and var. glauca, Australian cycads with peculiar repeatedly forked pinne. It is believed that such resemblances are purely fortuitous and in no way discredit the evidence furnished by fossil foliage, although it is not overlooked that some of the species referred to Baiera may not be related to those forms of Batera whose botanical relations have been demonstrated. In all the species the leaves are repeatedly and dichotomously inciso-partite and are distinguished from Ginkgo by the shortness of the petiole, and by the greatly elongated and narrow linear segments in the ultimate divisions of which there is no further forking of the veins. In habit, the leaves appear to have been borne in tufts at or near the summit of short axillary branches, much as in the modern Ginkgo, but this habit 1 Jurassic Fl., pt. i, 1900, p. 262. 3872 SysTEMATIC PALEONTOLOGY has not been demonstrated for but a few of the fossil species of either Baiera or Ginkgo. The staminate sporophylls are in lax strobili not very different from those of the modern Ginkgo, the micro-sporophylls are stalked and expand distally into from three to twelve sporangia which open by longi- tudinal slits. In Schenk’s figures of Baiera Muiinsteriana Heer the sporangia are in clusters of six or seven, while in the excellent examples of Baiera furcata Heer figured by Leuthardt (1903), they are three or four in number, exactly as is sometimes the case in the modern Ginkgo." The megasporangia (carpels) in Baiera were apparently always more than two in number (the usual number in Ginkgo*), and were borne on short branching stalks. It is worthy of mention in this connection, that some of the older Potomac forms described as species of Carpolithus, eg. C. fasciculatus Font., C. ternatus Font., C. virginien- sis Font., etc., are possibly Baiera carpels. The genus appears in the Permian of both Europe and America, and continues after the close of the Lower Cretaceous (Raritan formation of New Jersey, Atane beds of Greenland). It is very abundant in the Rhetic beds and continues to be a prominent element in Mesozoic floras throughout the Jurassic and well into the Lower Cretaceous, occurring most abundantly, perhaps, in the Jurassic. BAIERA FOLIOSA Fontaine Plate LIX Baiera foliosa Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 213, pl. xciv, fig. 13. Description.—“ Leaves numerous, grouped in bundles or tufts at the summit of short, stout, annual growths, having their basal portions long, slender, and gradually narrowing into a pedicel; their upper por- *Coulter records as many as three or four sporangia in occasional modern Ginkgo sporophylls although normally the sporangia are two in number. Morph. of Spermatophytes, vol. i, 1901, p. 38. ? Both Strasburger, Fujii, and Seward and Gowan record instances in which these shoots in the modern Ginkgo bear several ovules. MARYLAND GEOLOGICAL SURVEY 373 tions dichotomously divided into a small number of strap-shaped laciniz, the ultimate ones being a little over 1 mm. wide; nerves slender, ‘forking at long intervals, with branches parallel. This plant, evidently a true Baiera, is very rare, the specimens, few in number, being, with the exception of the one figured, found in small fragments. The leaves at the summit of the short twigs seem to have been very numerous and more slender than in the Jurassic Baieras.”—Fontaine, 1890. A single additional specimen, which in some respects is more complete than any of the earlier ones of this species, was collected some years ago by Mr. Bibbins, from the locality known as Sailors’ Tavern on the James River. It shows a flattened shoot 3 cm. long, very thin proximad and gradually thickening to the rounded apex. As preserved in a much shrunken condition the apical portion of the twig is 8 mm. in the trans- verse diameter by about 3 mm. in thickness so that in life it could hardly have been less than 5 mm. in diameter. The leaves are arranged in a low spiral, each one inserted separately on a rounded subrhomboidal boss placed about 2 mm. apart. These bosses are more or less obliterated in the basal 11 mm. of the shoot. The leaves are thick and are covered with an epidermis of thick-walled cells. The petiole is lenticular in cross section, 1.5 mm. wide, appearing as flat on the impressions. [t is 5 to 10 mm. in length to the height of the first subdivision. At this point the leaf splits into two or three major divisions which soon subdivide into slender, elongated segments, which are only about 0.5 mm. in diameter. Owing to the fragmentary nature of these ultimate segments their length cannot be determined. It is quite clear, however, that the present species is an undoubted gymnosperm and not a fern. This species in its slender, graceful form, is very suggestive of the widespread Batera furcata (L. & H.) F. Brayn of the Jurassic. It resembles the ginkgoes in having the leaves borne on short shoots, but in the present species the leaves were not deciduous as they are in the modern Ginkgo, but were retained for several years as the specimen. clearly indicates. With the exception of its much smaller size the present species is 374 SysTEMATIC PALEONTOLOGY very close to the Lakota leaves which Fontaine* identified as Czeka- nowskia nervosa Heer.” The latter are certainly referable to Baiera and not to Czekanowskia as are Heer’s type specimens in all probability. The Potomac species may also be compared with the two small-leafed species described by Nathorst, from the lowermost Cretaceous or late Jurassic of Advent Bay, Spitzbergen, as Baiera spetsbergensis, and Batiera graminea.” The method of arrangement of the leaves is un- known in these Arctic species, and their apparent resemblance to the Potomac species may be confined to the size and outline of the leaves. It may also be compared with Baiera Brawniana (Dunker) Bron- gniart described by Dunker’ from the Wealden of Germany as a Jean- paula and referred to Baiera by Brongniart.’ This species is slightly larger than the Potomac species but it is otherwise very similar, It has ‘been recently identified by Seward’ from the Jurassic of northeastern Scotland, but it may be questioned whether the latter should not rather be compared with some of the described Jurassic species. Occurrence—PatTuxENT Formation. Near Dutch Gap Canal and Sailors’ Tavern, Virginia. Collections—U. S. National Museum, Johns Hopkins University. Order CONIFERALES Family TAXACEAE Subfamily TAXEAE Genus CEPHALOTAXOPSIS Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 235] The utility of a new generic designation for the Potomac forms included in this genus, is not altogether obvious with Cephalotaxites and * Fontaine, in Ward, 19th Ann. Rept. U. 8. Geol. Surv., pt. ii, 1899, p. 685, pl. clxix, figs. 1, 2. * Heer, Cont. Fl. Foss., Portugal, 1881, p. 18, pl. xvii, figs. 5-8, 10, 11. ®>Nathorst, Zur Mesozoische Flora Spitzbergens, Kgl. Svenska . Vetens.- Akad. Handl., Band xxx, No. 1, 1897, p. 53, pl. iii, figs. 6-12. *Nathorst, Ibid., p. 54, pl. iii, fig. 13. * Dunker, Monogr. Norddeutsch Wealdbild., 1846, p. 11, pl. v, figs. 2, 4. *Brongniart, Tableau, 1849, p. 107. "Seward, Trans. Roy. Soc. Edinb., vol. xlvii, pt. iv, 1911, p. 680, tf. 9b. MaryLANpD GroLocioaL SuRVEY 375 Tazites already in use, but as it is in the literature and differentiates an abundant type which is at least specifically distinct from the species usually referred to the two genera just mentioned, it is retained in the present publication. It may be characterized as follows: Much branched stout limbs, apparently in a single plane, although it is impossible to determine to what extent this is due to pressure during fossilization. Leaves flat, linear-lanceolate, coriaceous and persistent, rather variable in size, mucronate tipped; base slightly decurrent and twisted; midrib broad and flat, bordered on either side below by a stomatal groove. The leaves are distichous in habit but the phyllotaxy was undoubtedly spiral as it is in so many other gymnosperms with the distichous habit, and is attested by the twisted leaf bases. No fruits have been found upon any of the abundant foliage specimens although certain associated species of Carpolithus* are mentioned by Professor Fontaine as the probable fruits of this genus, which are assumed to have been drupe-like with a bony seed after the manner of the existing species of Podocarpus and Cephalotarus. This may well have been the case, the fact that no fruiting specimens occur in the abundant sterile material lends some support to this interpretation, since such fruits would stand far less chance of successful transportation by water and subsequent fossilization, than would the woody, buoyant cones of the majority of the conifers. With the genus Tumion probably present in the Virginia Potomac, and with Nagetopsis representing the subfamily Podocarpex, the family Taxacee is abundantly represented in the Lower Cretaceous, and when the individual abundance is considered rather than the specific differ- entiation it must be admitted that this family furnishes an important element in the Potomac flora. The existing distribution of the Taxacee is shown on the accompany- ing sketch map of the world (Fig. 12), the subfamily Taxes being represented by horizontal lining and the subfamily Podocarpeex by vertical lining. leg. O. fasciculatus, C. mucronatus, C. sessilis, C. ternatus. 376 Systematic PALEONTOLOGY Heer* has described a leafy twig from the Patoot beds of Greenland (Senonian) bearing a large solitary drupe-like fruit which he calls Cephalotaxites insignis, an identification which Solms-Laubach” seems to consider probable. Bertrand* has described structural material of fruits allied to Cephalotacus under the name of Vesquia Tournaisii from the Aachenian of Belgium and the present writer has described * similar fruits which are common in the Upper Cretaceous of the Southern Atlantic Coastal Plain. Cophalotaxus Podocarpus DD, tn Mm me tI ail e i ewe Fig. 12.—Sketch map of the world showing the approximate distribution of the existing Taxacezx, horizontal lining —subfamily Taxex, vertical lining = subfamily Podocarpee. The existing genus Cephalotacus Sieb. and Zucc., contains four species confined to the Chinese-Japanese region. It was evidently much more widespread in former geologic times and to it should possibly be referred some of the leafy twigs included in the genus Tawites Bron- 1 Heer, Fl. Foss. Arct., Bd. vii, 1883, p. 10, pl. lili, fig. 12. ? Solms-Laubach, Fossil Botany, 1891, p. 61. ®> Bertrand, Bull. Soc. Bot. France, t. xxx, 1883, p. 293. *Berry, Bull. Torrey Club, vol. xxxvii, 1910, p. 187. MARYLAND GEOLOGIOAL SURVEY 3877 gniart. Fruit of three species of Cephalotacus, apparently identified corerctly, are described by Kinkelin* from the Pliocene deposits of Germany. ° CEPHALOTAXOPSIS MAGNIFOLIA: Fontaine Plate LX, Fig. 1 Cephalotaxopsis magnifolia Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 236, pl. civ, figs. 4, 5; pl. ev, figs. 1, 2, 4; pl. evi, figs. 1, 3; pl. evii, figs. 1, 2, 4; pl. cviii, figs. 1, 3, 4. Cephalotaxopsis ramosa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 237, pl. civ, figs. 2, 3; pl. evi, figs. 2, 4; pl. evii, fig. 3; pl. eviii, fig. 2. ; Cephalotaxopsis magnifolia Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc. Amer., vol. v, p. 450. ? Cephalotazopsis sp., Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc., Amer., vol. v, p. 450. Cephalotaxopsis magnifolia Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 686, pl. clxii, fig. 1b; pl. clxix, figs. 3, 4. ? Cephalotaxopsis ramosa Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 258 (7), pl. Ixviii, figs. 5-7 (?) (non p. 311, pl. lxxiii, fig. 8, which is a species of Oleandra, or p. 547, which is Nageiopsis angustifolia). ? Cephalotazxopsis ? rhytidodes Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 258, pl. Ixviii, fig. 8. Cephalotaxopsis magnifolia Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 299. Description.—Branches very stout, more or less branched, in some instances apparently in whorls through the suppression of the terminal bud and the development of the lateral shoots. Leaves distichous in habit, but probably with a spiral phyllotaxis, strikingly similar to those of the modern species of Cephalotaxus, linear-lanceolate in outline, rather abruptly rounded at the base and tapering gradually upward. Apex with a mucronate point. Length 2 cm. to 6 cm. averaging 4 cm. or 5 cm., and becoming regularly smaller distad and also smaller at the base of the new shoots. Width 3 mm. to 4 mm. Texture coriaceous. The midrib is broad and flat occupying about 1/17 of the diameter of the 1Engelh. and Kink., Abh. Senckenb. Naturf. Gesell., Bd. xxix, Hft. iii, 1908, p. 194, pl. xxiii, figs. 9, 13. 378 SysTEMATIC PALEONTOLOGY leaf. The epidermal cells are arranged in rows; they are small in size and thick-walled, quadrangular or slightly hexagonal in outline, rang- ing from proportions but slightly longer than wide to those in which the length is about 3 times the width. On the lower surface of the leaf on either side of the midrib, commencing one-fifth of the distance to the margin and occupying a width of one-fourth the distance to the margin are the stomatal grooves. They are deeply sunken and appear to have been floored with thin walled cells not well preserved. There is some evidence of the occurrence of a woolly scurf in these grooves but the preservation is such that this cannot be positively asserted. ‘The ae. Rae OH 9 0 o GH © os oR Ho? 9 0 HH SCH? 9 OIA a 00 6 " 2 CH HO! © 005) USCA OHOH Fig. 13.—View showing the whole midrib and the cuticle of one-half the lamina of Cephalotaxopsis magnifolia, x 110. stomata were comparatively large and irregularly scattered in the floor of the groove. They are without definite arrangement or orientation as the accompanying figure well shows. The guard cells are two in num- ber, long, much curved and slender. This species is exceedingly common in the Patuxent formation of Virginia to which it appears to be confined in the coastal plain. Although it has not yet been reported from the Kootanie formation of the Mon- tana area, it is present in both the Lakota and Fuson formations of the Black Hills Rim and in both the Upper Knoxville and Horsetown beds of the Shasta of California. At no localities, however, is it as abundant MARYLAND GEOLOGICAL SURVEY 379 as in the lowest Potomac of Virginia. It is strikingly like the modern Cephalotazus in appearance and may also be compared with various fos- sil species of Tazites. , Occurrence.—PaTUXxENT Formation. Fredericksburg, near Dutch Gap, near Potomac Run, Virginia. Collection —U. S. National Museum. CEPHALOTAXOPSIS BREVIFOLIA Fontaine Plate LX, Fig. 2 Cephalotaxopsis brevifolia Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 238, pl. cv, fig. 3; pl. evi, fig. 5; pl. cvii, fig. 5. Cephalotaxopsis microphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 238, pl. eviii, fig. 5; pl. cix, fig. 9. Cephalotaxopsis brevifolia Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 300. Description.—Ultimate branches alternate and rather slender. Leaves distichous in habit, narrowly lanceolate, 7 mm. to 21 mm. in length, averaging 10 mm. io 12 mma. Width 1 mm. to 3 mm., averaging about 2mm. Apex and base almost equally acute, the base slightly less so. Texture coriaceous. Fontaine says of this species: “ Midnerve slender.” It is, on the contrary, extremely broad but flat and not prominent. In the specimen figured which is Fontaine’s pl. cvi, fig. 5, the midrib occupies one-fifth of the maximum width of the leaf. This specimen exposes the upper surfaces of the leaves in consequence of which the midrib and stomatal bands are obscured. The photograph will also serve to empha- size the idealization and inaceuracy of the former figures of this plant. This species, which may simply represent certain terminal or abortive shoots of the preceding, is not at all common and is confined to the Patuxent formation of Virginia. It may be profitably compared with some of the Mesozoic species of Tasites. Occurrence—PatTUxeNT Formation. Fredericksburg, near Dutch Gap, near Potomac Run, Virginia. Collection.—U. 8. National Museum. 380 SYSTEMATIC PALEONTOLOGY Subfamily PODOCARPEAE Genus NAGEIOPSIS Fontaine [Mon. U. 8. Geol. Surv., vol. xv, 1890, p. 194.] This genus was founded by Fontaine in 1890 for forms apparently allied to the modern species which make up the Nageia section of the genus Podocarpus. He characterized it as follows: “Trees or shrubs with leaves and branches spreading in one plane; leaves varying much in size and shape; those towards the base of the twigs sometimes smaller than those higher up, distichous mostly, or rarely subdistichous, opposite and persistent, attached by a short, slightly twisted footstalk, usually to the side of the twig, more rarely slightly within the margin on the upper or under surface of the stem, either attenuated towards the base or abruptly rounded off there, at their ends acute or subacute; nerves several, coalescing at base to form a footstalk, forking immediately at the base or a short distance above; then approximately parallel to near the tips of the leaves, where they are somewhat crowded together, but do not converge to a union, ending in or near the extremity.” The diagnostic characters which deserve emphasis are the branching habit, the persistent leaves and the parallel veins which do not converge to any great extent in the apex of the leaf. These all serve to distin- guish the species of Nageiopsis from the cycadaceous fronds or leaflets with which they are most likely to be confused. The genus Podozamites for example, which is usually considered to be cycadean, although Seward suggests that it may be araucarian, is very similar in appearance; so similar in fact that Professor Fontaine included a number of Podozamites leaflets in his various species of Nageiopsis. But Podozaméites is usually represented by detached leaves, hence it was deciduous in habit; the ‘fronds are not known to branch, which habit is not only a distinguishing character but an argument against an araucarian affinity; finally, the veins converge, more or less, apically. It has seemed wiser in considering detached and fragmentary leaves such as are those specimens which have been referred to. Nageiopsis from the Shasta, Lakota, and Kootanie horizons to fully indicate their MaryLanp GEoLoGIcaL SuRVEY 381 extremely doubtful character. A similar course is pursued in regard to the affinity of some of the fragmentary detached specimens of Nageiopsis, so called, from higher horizons in the Potomac Group. In cases where there is absolutely no evidence that they are so related they have been referred to Podozamites or Zamites, genera broad enough to include them without the implications and the contravention of the generic diagnosis which would be involved in retaining them in Nageiopsis. Throughout the whole order Coniferales the phyllotaxy is as a rule spiral, more rarely it is cyclic in character. A true distichous or two- ranked arrangement is unknown, although a great many conifers with a spiral phyllotaxy are markedly distichous in habit, as for example, Tarodium, Araucaria, Tumion, Taxus, etc. It seems probable that Nagetopsis was no exception to the general rule; in fact some specimens show leaves inserted on all four sides of the stem. More often, how- ever, the exact method of attachment is obscured, but the more or less twisted base argues strongly for a spiral phyllotaxy. A distichous habit is strongly emphasized in fossil impressions which have been subjected to more or less compression, just as in the case of pressed herbarium specimens. There is a suggestion in some specimens of Nagetopsis that the base was markedly decurrent as in the modern Araucaria Bidwilli. This is furnished by- the extraordinarily large size of some of the stems, which are irregularly expanded and contracted as if certain of the decurrent leaf bases had been spread out somewhat in the flattening. which accompanied fossilization. This feature is especially well shown in the portion of the specimen of Nageiopsis zamioides previously figured.” The stem is broad at the base, giving off on either side sub-opposite leaves with apparently sheathing decurrent bases. Above their insertion the. stem is considerably narrowed, passing to a portion obscurely preserved. Above this point it is at least twice as broad, contracting to form the narrow base of the right-hand leaf, while just above the main stem is continued as a much narrowed twig, the next leaf above, that on the left, having its base concealed behind the twig. In no instance is the 1 Berry, Proc. U. S. Natl. Mus., vol. xxxviii, 1910, p. 191, fig. 1. 382 SysTEMATIC PALEONTOLOGY preservation as good as could be desired, so that the question can- not be definitely settled, but such examples, as that figured go a long way toward proving that at least some of the forms referred to Nageiopsis had strongly decurrent leaves and a spiral phyllotaxy. Similar features are shown in some of the specimens of Nageiopsis angustifolia and are indicated in the figures of this species on pl. I xiii. Fourteen supposed species have been described from the Potomac Group, an additional one from the Kootanie, and Prof. Seward recog- nizes a species in the English Wealden and doubtfully records a repre- sentative from the inferior Oolite of Yorkshire. The genus is also possibly represented in the Neocomian of J. apan by specimens which have been identified as Podozamites, but this is far from being demon- strable. The Potomac forms, excluding those fragmentary species which are not here recognized as related to Nageiopsis, fall naturally into three species characterized respectively by the possession of very long, linear leaves, very narrow lanceolate leaves, and ovate-lanceolate leaves. They are especially characteristic of the Patuxent formation, in fact the bulk of the unequivocal material comes from the single locality at Fredericksburg, Va: They evidently survived the close of the Patuxent, however, characteristic specimens of Nageiopsis angustifolia occurring in the lower beds at Federal Hill in Maryland. Their presence elsewhere in the Patapsco formation is probable, but the evidence is not wholly satisfactory. Regarding the botanical affinity of Nagetopsis Professor Fontaine has repeatedly pointed out its striking resemblance to Podocarpus. While admitting this resemblance both Nathorst and Seward have sug- gested Araucaria for comparison. Although there is, for example, considerable similarity between Nagetopsis zamioides and Araucaria Bidwilli, where in the genus ~Araucaria is there an analogue of Nageiopsis longifolia? In addition the Araucaries have their leaves much crowded and the phyllotaxy is spiral while in Nageiopsis the leaves are much more remote and the evidence for a spiral phyllotaxy is not 1This is probably the true affinity of Seward’s Lower Oolite Nageiopsis. MARYLAND GEOLOGICAL SURVEY 383 conclusive. Araucaria has markedly decurrent leaves and this character also cannot be demonstrated for Nageiopsis although as the writer has elsewhere shown, there is some evidence for both this and the preceding character in some of the specimens. Taking into account all of the facts obtainable the reference of Nageiopsis to the Podocarpee seems reasonably well established, although the possibility of their relation- ship with the Araucariee should be kept in mind. The existing species of Podocarpus comprise about two score forms and they are as dominant representatives of the Coniferales in the Southern Hemisphere as are the pines in the Northern. They extend northward to China and Japan through the East Indian region and have representatives in all three of the great Southern land masses. This peculiar distribution in itself may be considered as an indication of an extensive geological history, although the records of this history are not nearly as complete as they are for many other genera. To summarize briefly there are fifteen or more described species coming chiefly from the European Tertiary and one of these has been doubt- fully recognized by Lesquereux in this country at Florissant, Col. The extra-American distribution includes Eocene species in England, Scotland, France, Italy and Australia; Oligocene species in France, Germany, Switzerland, Italy, Styria, Tyrol and Greece; Miocene species in France, Styria and Croatia; and Pliocene species in Italy. The descendants of Nageiopsis have not, however, been recognized in later American deposits. The comparison of Nageiopsis with Podocarpus is more especially with the section Nageia, one of the four sections into which Hichler (in Engler and Prantl) divides Podocarpus. Nageia, formerly regarded as a distinct genus, has a broad form, numerous parallel veins and lacks a midrib, the latter being present in the other three sections of the genus. It may be questioned whether the reduction of Gaertner’s genus to a section of Podocarpus L’Herit., as clearly expresses the natural facts as they would be emphasized by its retention as a distinct genus. Nageia has about 2 dozen species ranging from Japan southward to the East Indies and New Caledonia. 25 384 SYSTEMATIC PALEONTOLOGY NAGEIOPSIS LONGIFOLIA Fontaine * Plate LXI Nageiopsis longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 195, pl. Ixxv, fig. 1; pl. Ixxvi, figs. 2-6; pl. lxxvii, figs. 1, 2; pl. Ixxviii, figs. 1-5; pl. Ixxix, fig. 7; pl. Ixxxv, figs. 1, 2, 8, 9. Nageiopsis crassicaulis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 198, pl. Ixxix, figs. 2, 6; pl. lxxxii, fig. 1; pl. lxxxiv, figs. 3, 9, 11. Nageiopsis longifolia ? Font., 1894, in Diller and Stanton, Bull. Geol. Soc., Am., vol. v, p. 450. Angiopteridium strictinerve Fontaine, 1894, in Diller and Stanton, loc. cit. Nageiopsis longifolia ? Font., 1896, in Stanton, Bull. U. S. Geol. Surv., No. 133, p. 15. Angiopteridium strictinerve Fontaine, 1896, in Stanton, loc. cit. Nageiopsis longifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xIvili, 1905, pp. 259, 311, 484, 491, 510, 528, 548, 557; pl. Ixviii, figs. 9- 12; pl. Ixxiii, fig. 9 (non pl. xlv, figs. 1-5). Nageiopsis longifolia ? Knowlton, 1908, in Diller, Bull. Geol. Soc., Am., vol. xix, p. 386. ‘ Nageiopsis longifolia Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 189. Description—Branching leafy twigs of large size, stout and thick, apparently branched in approximately one plane. Leaves linear-lanceo- late, often slightly curved, somewhat inequilaterally narrowed into a short slightly twisted petiole; above, gradually narrowed to the acute or subacute tip. Length 8 to 20 cm.; width 5 mm. to 1.3 em. The leaves are not crowded and usually appear opposite or sub-opposite as if inserted on the lateral margins of the stem although at times they seem to be attached to its upper or lower side. As previously remarked none of the material is conclusive in regard to the phyllotaxy. Veins 9 to 12 in number, usually 10, forking only at the base and running parallel until they abut against the leaf margin, about .? mm. apart, - somewhat coarser in calibre than in the other members of the genus, distinct on both surfaces of the lamina and apparently not immersed. Leaf sub- stance not coriaceous. ‘Irites alaskana Lesqg. is made a synonym of this species in Monograph xlviii. According to the principles so often set forth by Prof. Ward this species should be renamed if Irites alaskana is included in it, since the latter was published 3 years before Nageiopsis longifolia. As the Alaska remains are not those of a Nageiopsis this name is omitted from the synonymy. MaryYLAND GEOLOGICAL SURVEY 385 This species is quite distinct from its congeners and the great develop- ment of its evergreen foliage must have rendered it a most striking object in life. Included under this species are the few and rather poor remains upon which Fontaine founded Nageiopsis crassicaulis. All but one of the specimens which that author so names are fragments of detached leaflets, somewhat shorter and broader than the typical leaves of Nageiopsis longifolia, but absolutely uncharacteristic and incapable of identification. The specimen with leaves attached is obviously a poorly preserved fragment of a twig of Nageiopsis longifolia. This species occurs abundantly in characteristic and fine specimens at Fredericksburg. It has also been recorded from a large number of localities in Virginia and Maryland mostly as detached specimens gener- ally with the base and apex missing so that the record of its range is somewhat unreliable, nor can it be otherwise from the nature of the material. Professor Fontaine has recorded this species from Cape Lisburne, Alaska; from several Californian localities referred to the Upper, or Lower Cretaceous portion of the Shasta Group; from the Kootanie for- mation at Geyser, Montana; and from the Lakota formation in the western Black Hills at Barrett, Wyoming. Referring to ‘these very briefly, it may be said that the Alaska locality is much older than any of the others and the fossils referred to this species, previously identified by Lesquereux as Irites alaskana Lesq., and Batera palmata Heer, are entirely uncharacteristic and in the writer’s judgment are in no wise related to Nagetopsis. The Shasta records are based entirely on small fragments which show only the middle portion of leaves and often lack the venation. The following quotation from Fontaine’s report (1906, p- 259) sufficiently indicates their reliability: “The presence of N.. longifolia in the flora of the Shasta formation cannot be positively determined from the specimens found.” : The Kootanie record is likewise extremely doubtful and is based on five or six fragments from Geyser which are unattached and show neither bases nor tips. The specimens reported from the Lakota forma- 886 SYSTEMATIC PALEONTOLOGY tion also are all fragmentary and uncharacteristic, and while we would expect to find this species in the West, the nature of the remains thus far collected scarcely justifies the identifications which have been based upon them, and as furnishing facts for stratigraphic correlation they are absolutely valueless. Occurrence.—PATUXENT Formation. Fredericksburg, Potomac Run, Telegraph Station (Lorton), Cockpit Point, Kankeys, Dutch Gap, Vir- ginia. ARUNDEL Formation. Langdon, District of Columbia. Patapsco Formation. Federal Hill (Baltimore), Vinegar Hill (7), Ft. Foote, Maryland; Mt. Vernon, Chinkapin Hollow (?) Brooke, Deep Bottom (?), Virginia. Collection —U. S. National Museum. NAGEIOPSIS ZAMIOIDES Fontaine ‘ Plate LXII, Figs. 1, 2; Plate LXIIT Nageiopsis zamioides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 196, pl. Ixxix, figs. 1, 3; pl. Ixxx, figs. 1, 2, 4; pl. Ilxxxi, figs. 1-6. Nageiopsis recurvata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 197, pl. lxxv, fig. 2; pl. Ixxix, fig. 4; pl. lxxx, fig. 3. Nageiopsis decrescens Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 199, pl. Ixxvii, fig. 3. Nageiopsis ovata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 199, pl. Ixxvii, fig. 4; pl. Ixxx, fig. 5. Nageiopsis heterophylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 201, pl. Ixxxiv, fig. 4; pl. Ixxxvi, figs. 6, 7; pl. Ixxxviii, figs. 2, 5. Nageiopsis microphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 201, pl. lxxxiv, fig. 6; pl. Ixxxv, fig. 14; pl. Ixxxvi, figs. 1-3, 5. Nageiopsis cf. N. heterophylla Font., Seward, 1895, Wealden Flora, pt. ii, p. 211, pl. xii, fig. 3. Nageiopsis zamioides Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol xlviii, 1905, pp. 510, 521, 528, 545. Nageiopsis heterophylla Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 219 (?), 483, 520, 548, 561, pl. exvii, fig. 6. Nageiopsis microphylia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv. vol. xlviii, 1905, p. 484. . Nageiopsis zamioides Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 191, tf. 2. Description.—Leaves ovate-lanceolate, proportionately shorter and wider than in MN. angustifolia and much shorter and more rounded in MaryYLAND. GEOLOGICAL SURVEY 387 outline than in N. longifolia; broadest toward the rounded base, the maximum width observed being 1.5 cm. although the average width is much less and may be put at 1 cm. or slightly less; very variable in size, tip generally acute although an occasional specimen may be obtuse. The greatest length observed is 8 cm. but the average length is much less than this and may be placed at 3 to4.cm. Occasional twigs like the solitary specimen described as N. decrescens or the specimens referred to N. microphylla may be much smaller than the above. The latter are. however of the same general shape while in the former case the fact that the larger leaves at the base of the specimen are replaced by very minute leaves indicates that the specimen is an abnormal twig. Veins fine in calibre, somewhat remote, generally 6 to 9 in number, forking at the base and diverging rapidly at first, then parallel until they abut upon the margin. While it might seem at first sight that too great a variety of leaf forms had been lumped under this specific name the great variability of the leaves on single twigs should be kept in mind. The leaves in the type forms are commonly smallest toward the base of the twigs as they are also in the WN. ovata forms. In N. decrescens the basal leaves are 100 per cent longer than are the succeeding leaves. In the forms described by Fontaine as N. heterophylla the leaves are especially varia- ble, some being identical with those he called NV. microphylla while others are like those he calls N. decrescens, other still simulating his NV. ovata and N. zamioides with two or more of these types present on the same twig. Others referred by him to N. zamtoides show an equally wide range of variation. Fig. 1 on pl. lxiii shows a figure of a small specimen labelled NV. zamioides which has but five leaves and includes leaves easily referable to Fontaine’s species microphylla decrescens, ovata, heterophylla and zamioides leaving only his NV. recurvata to be accounted for. Since these latter are detached there is really no proof that they are correctly identified. ‘They are, however, exactly like certain somewhat falcate leaves of N. zamioides found on twigs among normally straight leaves, so that there is little doubt but that the Virginia specimens are refer- able to this species. The form identified as N. recurvata from Vinegar 388 SYsTEMATIC PALEONTOLOGY Hill, Md., is different from the others and is a Podozamites leaflet. Corroborate evidence is furnished by the similarity in venation char- acters and in the fact that all but one of the six so-called species, NV. decrescens, are from the single limited exposure at Fredericksburg, and this was described from a nearby and probably synchronous outcrop and is really present at Fredericksburg attached to a twig labelled N. hetero- phylla. Four of them are again associated at the Dutch Gap locality. Again at Fredericksburg the typical forms of zamioides of Fontaine are very abundant while the variants which he described as separate species are represented in some cases by a single specimen, in others by but two or three specimens. A glance at the various figures in Fontaine’s monograph and a perusal of the accompanying descriptions will be convincing, and this is only emphasized by a comparison of the specimens themselves. Compare for example fig. 5 of ovata with fig. 3 of zamioides and it will be seen that they might have been drawn from the same specimen. This is likewise true when the single specimen of N. decrescens is com- pared with figs. 3 and 6 of NV. microphylla, and similar comparisons can be made back and forth indefinitely. Seward (Wealden Fl. pt. ii, p. 211, pl. xii, fig. 3, 1895) describes and figures a few small fragments from the English Wealden at Hastings and Hcclesbourne which he compares with WN. heterophylla Fontaine. The specimen figured shows well the branching habit and as near as can be judged is a species of Nageiopsis. Since, however, the name NV. heterophylia Fontaine becomes a synonym of N. zamioides Fontaine the English fossils may be given the latter name without much question. Occurrence—PatTuxENT Formation. Fredericksburg, Dutch Gap, Cockpit Point, Potomac Run, Virginia. ARruNDEL Formation. Bay View, Hobbs Iron Mine (?), Maryland; Langdon, District of Columbia. Parapsco Formation. Federal Hill (Baltimore), Vinegar Hill, Well- hams (?), Overlook Inn, Ft. Foote, Maryland; Chinkapin Hollow (?), Virginia. Collection —U. 8. National Museum. MARYLAND GEOLOGICAL SURVEY 389 NAGEIOPSIS ANGUSTIFOLIA Fontaine Plate LXIII, Figs. 3, 4 Nageiopsis angustifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 202, pl. Ixxxvi, figs. 8, 9; pl. lxxxvii, figs. 2-6; pl. Ixxxviii, figs. 1, 3, 4, 6-8; pl. Ixxxix, fig. 2. Nageiopsis angustifolia Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, 1899, p. 684, pl. clxviii, fig. 7. Nageiopsis angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 219, 491, 516, 528, 560, pl. cxvii, figs. 4, 5. _ Cephalotaxopsis ramosa Font. ? 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 547. Nageiopsis angustifolia Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 190. Description.—Much branched stems, of comparatively large calibre. Leaves variable in size, becoming smaller on ultimate twigs, but constant in their proportions; very long and narrow, linear-lanceolate, sometimes somewhat falcate, acute, averaging about 3 mm. in width in some in- stances only 1.5 mm. wide, greatest width observed 4 mm., length 2 to 7 cm., averaging about 5 cm.; veins of fine calibre, generally eight in number, sometimes observed to fork at the base. An abundant species suggestive of Cephalotaxopsis in general appearance. Occurrence-—PATUXENT Formation. Fredericksburg, Dutch Gap, Potomac Run, Virginia; 16th St., District of Columbia. ArunpEt For- MATION. Bay View, Md. Parapsco Formation. Federal Hill (Balti- more), Vinegar Hill (?), Wellhams, Ft. Washington, Ft. Foote, Mary- land; Mt. Vernon, Brooke, Virginia. Collection.—U. 8. National Museum. Family BRACHYPHYLLACEAE! Genus BRACHYPHYLLUM Brongniart [Prodrome, 1828, p. 109] The genus Brachyphyllum was proposed by Brongniart in 1828 for conifers with short, fleshy, spirally arranged leaves attached by their 1Consistent with the avowed policy of the writer not to crowd the Lower Cretaceous flora into the confines of the Taxonomic bounds inherited from a study of the existing flora from which the former is separated by many millions of years, a new family is demanded for these peculiar Mesozoic types. 890 SysTEMATIC PALEONTOLOGY broad rhomboidal bases. The type species Brachyphyllum mamillare from the Lower Oolite was described but not figured and was placed under the heading conifére doutense. In 1849* the same author compared this genus with the existing genera Arthrotazis, Widdringtonia and Glyptostrobus. Schimper in 1872* somewhat restricted the genus and also extended Brongniart’s diagnosis. Saporta also” gives a rather well-illustrated account of Brachyphyllum figuring Brongniart’s type and pointing out its doubtful botanical affinity. His diagnosis of the genus is as follows: “Rami sparsim pinnati ramulis alternis erectiusculis cylindricis, sepius rigidis; folia spiraliter inserta abbreviata vel brevissima basi late rhombea insidentia, in statu juvenili etiam minime producta, ceterum conica mamilleformia, apice obtusissime intus recurva, plerumque carnosa vel saltem firma crasseque coriacea, dorso autem plus minusve carinata glandulaque sepe notata, postea etatis decursu in caulibus adultis dilatata depressaque, areas scutellasque convexiusculas regulariter rhombeas hexagonulasque puncto medio signatas efformantia ; —strobili mediocres aut parvuli verosimiliter terminales, e squamis plurimis arcte imbricatis sursum lanceolatis aut rarius in apophysim incrassatis anticeque carinatis et post maturitatem sexus axin persistent- ibus constantes ;—semina minutissima ala brevi superata inversa liberaque in quacumque squama 1-3 ;—amenta mascula ovata globosaque, parvula, ut videtur axillaria, basi involucrata postque pollinisationem caduca, e squamulis arcte imbricatis antice in appendicem lancealatuin dilatatis composita.” Seward* regards Brachyphyllum as a purely provisional genus, the actual botanical position of which is very uncertain, and further states that it is quite probable that more than one family of conifers are included under this name. Comparisons have been made at various times with the modern subfamilies Araucariex, Taxodiew, and Cupressee, ‘Brongn., Tableau, 1849, p. 69. * Schimp., Traité, Pal. Végét., 1870, tome ii, p. 334. *Saporta, Pal. franc., 1884, tome iii, p. 310. ‘Seward, Wealden FI., pt. ii, 1895, p. 214. MaryLANp GEoLoGIcAL SURVEY 391 especially with the Tasmanian genus Arthrotaxis of Don and the arau- carian species Araucaria imbricata. Brachyphyllum may be defined as a genus of arborescent conifers the twigs of which are thick and club-shaped, irregularly distichous in their mode of branching. The leaves are squamate, very short, thick, appressed, and densely crowded. Phyllotaxis spiral. In life the leaves must have been more or less fleshy, mutual pressure causing them to assume a pentagonal or hexagonal outline, with a dorsal, slightly pro- jecting carina or boss becoming more or less obliterated with age. Leaf surface more or less striated, the strie converging to the obtuse apical point (at least this is true of our American Cretaceous species). The leaf-scars on old branches are said to be rhomboidal and continuous, remotely suggestive of Lepidodendron. A most remarkable species of this genus is Brachyphyllum spinosum Seward, of the English Wealden, a large robust form whose lateral branches have become reduced to stout pointed spines about 3 cm. in length and 5 mm..in diameter at the base, where they are covered with reduced leaves, furnishing the only instance. among the gymnosperms known to the writer where the branches are reduced to spines. A variety of cones have been referred to Brachyphyllum usually upon the unreliable evidence of association in the same stratum. Hven when cones are found in actual connection with the leafy twigs their preserva- tion is such that positive evidence of botanical relationship is not avail- able. Newberry* describes a large cylindrical cone with a length of 20 cm. and a diameter of 4 cm. and having spatulate scales, which he is quite positive is the cone of the Brachyphyllum so common in the upper part of the Raritan clays of New Jersey. As against these cones described by Newberry most cones referred to Brachyphyllum have been small and somewhat spheroidal in shape. Thus Zeiller describes branches of Brachyphyllum from the Lias of Madagascar which bore small ovoid cones with rhomboidal scales very suggestive of Sequoia and he seems to think it probable that some of 1 Seward, Wealden FL, pt. 11, 1895, p. 215, pl. xvii, figs. 1-6. 2 Newberry, Mon. U. 8. Geol. Surv., vol. xxvi, 1896, p. 51, pl. vii, figs. 3, 4. 6. 892 SysTEMATIC PALEONTOLOGY the forms of Brachyphyllum are referable to the Taxodiew while others have an affinity with the Araucariee. Saporta* figures elliptical Walchia-like cones which he found associated with Brachyphyllum jauberti, gracile, and moreauanum in the French Jurassic, while Heer * describes and figures spherical cones with polygonal scales attached to twigs of his Brachyphyllum insigne from the Lower Oolite of Siberia, and other records of a very similar nature might be mentioned. Fontaine has recorded three obscure varieties of small cones from the Potomac beds along the James River in Virginia which he refers to Brachy- phyllum.’ They are very indefinite and poorly preserved and are all probably of a single species. They resemble somewhat the cones which Saporta refers to this genus and may be correctly identified, but this is doubtful. Finally Hollick and Jeffrey have rendered it extremely probable * that the widespread coniferous scales of the mid-Cretaceous referred to Dammara are related to Brachyphyllum and these authors have proved, at least in the species formerly known as Dammara micro- lepis Heer from Staten Island, a relation to twigs of the Brachyphyllum type, which relationship would seem to effectually disprove the identity of the cones described by Newberry. Leafy branches and twigs very similar in appearance to those of Brachyphyllum in which, however, the leaves are less thick and more free and pointed are referred to the genus Echinostrobus which was founded by Schimper in 1872 for four or five Jurassic species of conifers, and it is to this Jurassic genus that Velenovsky refers two species from the Cenomanian of Bohemia,’ although these latter are both practically identical with Brachyphyllum macrocarpum Newb. from the nearly homotaxial American horizons. *Saporta, Plantes Jurassiques, tome iii, 1884, pp. 341, 349, 365, pl. clxv, figs. 1, 2; pl. elxvii, fig. 2; pl. clxxi, figs. 5-9. * Heer, FI. Foss. Arct., Bd. iv, Ab. ii, 1876, p. 75, pl. xiii, fig. 9. : * Fontaine, Mon. U. S. Geol. Surv., vol. xv, 1890, pp. 223, 224, pl. cxxxv, figs. 8, 9; pl. elxviii, fig. 2. *Hollick and Jeffrey, Amer. Nat., vol. xl, 1906, p. 200. *Velenovsky, Gym. bohm. Kreidef., 1885, p. 16, pl. vi, figs. 3, 6-8; Kvétena teského cenomanu, 1889, p. 9, pl. i, figs. 11-19; pl. ii, figs. 1, 2. MaryLANp GroLogicaL SurvEY 393 The geological range of Brachyphyllum like its geographical range is very great. The earliest recorded occurrence is that of a very doubtful species described by Feistmantel* from the Permo-Carboniferous of New South Wales (Newcastle beds). The genus reappears in the Upper Triassic, becoming prominent during the Jurassic and Lower Cretaceous, and dies out during the first half of the Upper Cretaceous. Recently discovered structural material has enabled Hollick and Jeffrey * to show that in the Upper Cretaceous species Brachyphyllum macrocarpum Newb., the leaves are attached by practically the whole ventral surface, only the margins being free and these sometimes overlap. They refer this species to the subfamily Araucaries on the evidence of the branched leaf trace, the mucilaginous contents of the resin canals, the Araucarioxylon type of flattened and alternating bordered pits, the lateral pits of the ray cells, and the absence in the phloem of regularly alternating rows of hard bast fibres. Jt would seem to the writer that while these characters show a certain relationship with the modern Araucaria stock there are constant differences which demand the refer- ence of this species to a separate family particularly as forms con- forming entirely to the Araucarian type in anatomy, vegetative, and reproductive structures, are present at this same horizon and also at much earlier horizons. ® BRACHYPHYLLUM CRASSICAULE Fontaine Plate LXIV, Figs. 1-6 Brachyphyllum crassicaule Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1890, p. 221, pl. c, fig. 4; pl. cix, figs. 1-7; pl. ex, figs. 1-3; pl. cxi, figs. 6, 7; pl. cxii, figs. 6-8; pl. clxviii, fig. 9. Brachyphyllum crassicaule Fontaine, 1906, in Ward, Mon. U.S. Geol. Surv., vol. xlviii, 1905, pp. 529, 557, pl. cxiii, fig. 6. Brachyphyllum crassicaule Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 305. Description.—“ Trees with large branches, irregularly’ pinnate; on the penultimate twigs the ultimate branches lower and next to the main branch subdivide pinnately into branches; those higher are un- 1¥Feistmantel, Paleont., suppl. iii, 1878, p. 97, pl. vii, figs. 3-6; pl. xvii. 2 Loe. cit. 394 SYSTEMATIC PALEONTOLOGY branched and simple; ultimate branches vary in numbers and closeness, sometimes few and remote, and again crowded, contiguous, almost touch- ing; towards the summit of the penultimate branches the ultimate ones become much crowded and grow gradually shorter, are cylindrical, and taper gradually to an obtuse point; leaf-scars of young leaves ellipti- cal in shape, slightly prolonged in the direction of the axes of the stems, and such leaves seem to have been fleshy, slightly convex, and with a free tip slightly keeled in the upper half; with age the leaves become broader and more convex, being broadly elliptical, almost circular, and they leave similar scars after their fall; when crowded and dilated with age the leaves and leaf-scars are subrhombic or rhombic in shape; the surface of the leaves, which is very rarely preserved, shows fine tubercles or dots arranged in curving lines parallel to their margins and converg- ing towards their tips; cones small, globular, or subelliptical in shape, attached laterally to the penultimate twigs, taking the place of ultimate branches; scales numerous, spirally arranged, touching, shape not made out, but probably with age rhombic and polygonal.’’—Fontaine, 1890. This species is fairly common in Virginia in beds of both Patuxent and Patapsco age while in Maryland it occurs exclusively, as far as known, in deposits referred to the Patapsco formation. ; All forms inthis genus are much alike superficially as may be seen by comparing the figure reproduced on pl. lxiv of B. mammuillare Brongniart, the type species from the European Lower Oolite, with the Potomac species, and these with the latest known American form, the widespread B. macrocarpum Newberry, which ranges from Greenland to Delaware, Alabama and Kansas and Wyoming and from the Raritan through the Magothy and Dakota to the Montana formation. B. crassicaule is very similar to the European B. obesum Heer’ with which Seward * unites it tentatively. This latter species is found in the English Wealden and in the Urgonian and Aptian of Portugal. One of Saporta’s figures of this species is reproduced on pl. lxv, fig. 3, and it will be seen that the European and American forms are very similar; + Heer, Contrib. Fl. Foss., Port., 1881, p. 20, pl. 17, figs. 1-4. *? Seward, Wealden FL, pt. ii, 1895, p. 218, pl. xvii, fig. 9; pl. xx, figs. 1, 2, 4. MaRyYLAND GEOLOGICAL SURVEY 395 however, since this similarity runs through all the members of this genus and these two species are so widely removed geographically it has seemed best to maintain their distinctness. B. obesiforme Saporta* from beds of Albian age in Portugal is also very similar to the forms under discussion. This species in its more slender specimens approaches very close to certain forms from the Upper Cretaceous of the Southern Coastal Plain (Tuscaloosa formation of Alabama, Eutaw formation of Georgia), which the writer has referred to the usually somewhat larger, more striate-leafed form Brachyphyllum macrocarpum Newb. Occurrence.—PaTUXENT Formation. Trents Reach and near Dutch Gap, Virginia. Parapsco Formation. Ft. Foote, Federal Hill, near Glymont, Stump Neck, Maryland; near Widewater, near Brooke, Dum- fries Landing, Virginia. Collections.—U. 8. National Museum, Maryland Academy of Sciences, Johns Hopkins University. BRACHYPHYLLUM PARCERAMOSUM Fontaine Plate LXV, Figs. 4, 5 Brachyphyllum parceramosum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 223, pl. cx, fig. 4. Brachyphyllum texense Fontaine, 1893, Proc. U. S. Natl. Mus., vol. xvi, p. 269, pl. xxxviii, figs. 3-5; pl. xxxix, figs. 1, la. Brachyphyllum parceramosum Fontaine, 1906, -in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 517, 538. Brachyphyllum parceramosum Berry, 1911, Proc. U. S. Natl. Mus., vol. x1, p. 306. Description.—“ Twigs branching sparingly and dichotomously; leaves and leaf-scars elliptical to subrhombic, with the longer dimensions in the direction of the length of the twigs; leaves convex, spirally arranged, showing a keel in their upper portions, closely appressed, contiguous, prolonged very slightly at the tips, branches cylindrical, of the same thickness throughout; so far as can be seen about 4 mm. in diameter.” —Fontaine, 1890. 1 Saporta, Fl. Foss., Port., 1894, p. 176, pl. xxxi, figs. 12, 18; pl. xxxtii, fig. 4; pl. xxxiv, fig. 8. 396 SysTeMATic PALEONTOLOGY This form which is of rare occurrence is possibly not specifically dis- tinct from B. crassicaule Font., which in turn is very closely allied to various European forms. It may be distinguished, however, from the preceding species by its slender branches which rarely fork and then in an apparently dichotomous manner (this is only apparent, however, and not real dichotomy) and by its more regular, pointed, slightly keeled leaves. The specimens from Glen Rose, Texas, described as new by Prof. Fontaine are not distinguishable from the Maryland and Vir- ginia specimens of B. parceramosum. B. parceramosum is retained as a distinct species because of the incon- clusive nature of the material and because it occurs in beds of somewhat greater age than B. crassicaule, and because in habit it more nearly resembles the less branched Jurassic types rather than the more regularly and pinnately branched Cretaceous types; the later type culminating in the type of Brachyphyllwm macrocarpum of the Upper Cretaceous. The great similarity among all of the species in this genus, when studied as poorly preserved impressions, tends to enforce caution on the student who would unite under one name forms which appear to be similar but which are widely separated either geologically or geographically. The European representative of B. parceramosuyn is B. obesiforme elongatum Sap. which occurs in the Albian of Portugal. Occurrence.—PaTUxENT Formation. Telegraph Station (Lorton), Virginia; New Reservoir, D. C. ARuNDEL Formation. Arlington, Maryland. Collection —U. S. National Museum. Family ARAUCARIACEAE Genus ARAUCARITES Presl {In Sternb., Fl. Vorwelt, fasc. ii, 1833, p. 203] This genus is characterized in the following terms by its describer : “ Strobilus ovalis, rotundato-obtusus, squamis densissimis Rami sparsi, subdichotomi. Folia imbricata, parva, crassiuscula. Strobilus unius speciei hucusaue notus multo minor illis specierum viventium, attamen MaryLanp GEoLoGicaL SURVEY 397 similitudo presertim cum strobilo juveni Araucarie brasiliane negari non protest.” Schimper* restricts the term to foliage remains, referring the cones and cone-scales described as Araucarites previous to his time to the genus Araucaria to which many of them are undoubtedly related. Sub- sequent workers have used the genus Araucarites entirely as a form- genus for remains of foliage, cones and cone-scales which seem to be more nearly related to the Araucarieer than to any other existing sub- family of the Coniferales, a relation which because of the inconclusive nature of the remains cannot be demonstrated. As such a form-genus Araucarites has proved to be a most convenient repository for single seeded cone-scales and large spherical cones as well as for impressions of foliage resembling that of the modern araucarias. Many species have been described, ranging in age from the Permian through the Tertiary. These are especially abundant in the Jurassic and Cretaceous. Fontaine took up this genus in Monograph xv for two classes of remains from the Virginia Potomac. These embraced an obscure cone from the lower Potomac (Patuxent) named Araucarites virginicus, with which he subsequently correlated other remains from higher horizons (Patapsco) which turn out to be those of Pinus vernonensis, and de- tached cone-scales named Araucarites aquiensis which are found to be characteristic remains in the later Potomac or Patapsco deposits, and as such possess a quite considerable stratigraphic value. Professor Fontaine has described three species of Araucaria based on the remains of foliage from the Potomac Group. These are omitted from the present work because of their extremely indefinite character. The first is Araucaria podocarpoides* described from the Patapsco for- mation at Brooke, Va., which resembles somewhat the foliage in the Colymbea section of Araucaria. This was based upon a single indistinct fragment which in all probability is a poorly preserved twig of Nagetopsis zamioides. 1 Schimper, Pal. Végét., tome ii, 1870, p. 252. 2 Fontaine, Mon. U. S. Geol. Surv., vol. xv, 1890, p. 249, pl. Ixxxvi, fig. 4. 398 SyYsTEMATIC PALEONTOLOGY The second, Araucaria obtusifolia, was based on a tiny specimen of undeterminable affinities from the Patuxent formation at Trents Reach, Va. The third, Araucaria zamioides,, was based on similar scant and indefinite material from the Patuxent formation at Potomac Run, Va., which its author states may represent a small species of Zamia-like cycad. While there are no reasons for a denial of the presence of Araucaria foliage in the Potomac flora (in fact there are strong reasons for predicting its presence), the foregoing species do not afford reliable data on this point. Many remains of cones and cone-scales have been described from various Mesozoic horizons as species of Araucaria or Araucarites, but it seems scarely worth while to enumerate them in the present connection since none resemble the present species at all closely. ARAUCARITES AQUIENSIS Fontaine Araucarites aquiensis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 264, pl. cxxxiii, figs. 8-12. Araucarites aquiensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 489, 514, 528. Description.—* Scales of the cones varying considerably in size and shape, attaining the maximum dimensions in length of 5 cm. and in width across the top of 3 cm. with the minimum of 3.5 cm. by 1.5 cm.; scales probably closely appressed and imbricated, wedge-shaped, and narrowed at base into a sort of foot-stalk, thickened at the summit, and rounded on the upper margin, with a depressed transverse furrow, very deciduous, and always found scattered singly and sparingly in the clay.”—Fontaine, 1890. These scales were described originally from the Brooke area where they are not uncommon. ‘The writer has collected similar scales at a number of localities within the Patapsco terrane but can add little to the foregoing description. No positive evidence of a single seed is observable on any of the specimens either old or new, although their form is sug- gestive of such a habit. They were compared by their describer with 1Tbid., pl. Ixxxv, fig. 13. * Ibid., p. 250, pl. exxi, fig. 1. MarYLAND GEOLOGICAL SURVEY 399 the modern genera Abies and Dammara, largely because of their obviously deciduous habit. While they are retained in the genus Araucarites they are probably more nearly related to Dammara than to Araucaria, since they more closely resemble both the Upper Cretaceous and the modern Dammara,cone-scales, and we know that the Upper Cretaceous species of Araucaria already had cone-scales very like those of the modern members of that genus and quite different from the scales under discussion.’ The present species is confined to the Patapsco formation and is apparently a type fossil for this horizon. The Lakota formation of the Black Hills region has furnished two species of cone-scales, Araucarites wyomingensis Fontaine and Arauca- rites cuneatus Ward, both of which are smaller and thicker than the present species. Occurrence—Patapsco Formation. Ft. Foote (common), Prince George’s County, Maryland; near Brooke, R. F. & P. cut at Aquia Creek, near Widewater, Mt. Vernon, Chinkapin Hollow (?), Virginia. Collection—U. 8. National Museum. ARAUCARITES PATAPSOOENSIS sp. NOV. Plate LXXVII, Figs. 5, 5a Description.—Deciduous cone-scales broadly rhomboidal in outline, rounded above and with nearly straight lateral margins below. As pre- served, 2.6 cm. in length by 3.3 cm. in greatest width, which is about midway between the apex and the base, 6 mm. in width at the base. The single incomplete specimen upon which this description is based shows the under (dorsal) surface of a rather large scale which at first sight appears to have subtended three or four seeds. A careful com- parison with the cone-scales of the existing species of the genus Araucaria leads to the conclusion that the organization of this Lower Cretaceous cone-scale was essentially like that which obtains in the modern species of Araucaria, among which the most similar are the cone-scales of Araucaria Bidwillt Hooker, a native of Australia. The cone-scales were 1 See Berry, Bull. Torrey Club, vol. xxxv, 1908, p. 258, pl. xvi. 26 400 SysTeMATIC PALEONTOLOGY single-seeded as indicated on the diagrammatic sketch that accom- panies the figure of this species and the seeds were large and truncate- spatulate in outline. It is assumed from the analogy furnished by Araucaria Jeffreyi Berry* from the lower part of the Upper Cretaceous that a more or less prominent ligule served to enclose the seed. The lateral margins of the scales are winged, but the wings are stiff and ligneous and it is the flutings of these wings due to drying which causes the scales to appear to have borne more than a single, medianly located seed. This appearance can be exactly matched in modern Araucaria cone-scales. The distal margin of the scale has disappeared in the fossil so that this part of the diagram together with the central spur must be regarded as hypothetical. It seems evident, that the cones of the ancestral forms of the Arau- cariee had already, as early as the Lower Cretaceous, acquired the habit and morphology which distinguish the modern members of this some- what isolated family. Occurrence.—Patapsco Formation. Widewater, Virginia. Collection—Johns Hopkins University. Family PINACEAE Subfamily ABIETEAE Genus PINUS Linné [Sp. Pl., 1753, p. 1000] Modern members of this genus are the dominant conifers of the northern hemisphere with about seventy species usually forming vast forest areas. There are considerable differences of opinion at the present time among morphologists as to the relative antiquity of the various members of the order Coniferales, the older view that the Abietee were a highly specialized and relatively modern type being questioned by Jeffrey and others. It would seem, however, that the old view not only has the fossil record exclusively in its favor but many morphological arguments to substantiate it. * Berry, Bull. Torrey Bot. Club, vol. xxx, 1908, p. 258, pl. xvi. MARYLAND GEOLOGICAL SURVEY 401 A very large number, perhaps as many as two hundred, fossil species of Pinus have been described, ranging in age from the Jurassic upward. The Jurassic has furnished pine-like leaves, as well as the remains of cones, which have formed the foundation of several species. While these records are for the most part not entirely unequivocal, Fliche and Zeiller* in a recent communication are positive of the identity of the cone which they describe from the French Portlandian. From horizons homotaxial with the Potomac Group, a number of forms have been re- corded. These include six species described by Heer from leaves in the Kome beds, three species from the Kootanie, one from the Lakota of the Black Hills, and one from the Trinity of Texas. Strata of Albian age in Europe are remarkable for the number, variety and excel- lent preservation of cones of Pinus, about a dozen species being known from England, Belgium, and France. The Upper Cretaceous records are frequent and conclusive, including the evidence of wood with structure preserved, and the genus becomes thoroughly cosmopolitan during the Tertiary period. The definite remains of Pinus in the Potomac Group are those of both cones and seeds constituting the fol- lowing single species, the cones of which sometimes crowd the strata of the Patapsco formation. In addition, both the older and the younger Potomac contain leaf remains which have been described by Professor Fontaine as species of Leptostrobus and Laricopsis. These are obviously not related to Leptostrobus or the modern Larix, and are included by the present writer in the form-genus Abietites, since the latter type of cones in the English Wealden material (Pinites) are borne on branches bearing long leaves like those named as above by Professor Fontaine. PINUS VERNONENSIS Ward Plate LXVI- Seed of Pinus ? sp., ? Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 272, pl. clxx, fig. 4. e Pinus vernonensis Ward, 1906, in Fontaine, Mon. U. S. Geol. Survey, vol. xiviii, 1905, p. 497, pl. cix, figs. 4-6. 1¥Wliche and Zeiller, Bull. Soc. Géol. France (iv), t. iv, 1904, p. 804. 402 SYSTEMATIC PALEONTOLOGY Pinus schista Ward, 1906, Mon. U. S. Geol. Surv., vol. xlvili, 1905, p. 531, pl. exii, figs. 13-15. Araucarites virginicus Fontaine, 1906, in Ward, Mon. U. 8S. Geol. Surv., vol. xlviii, 1905, p. 572, pl. cxix, fig. 8 (non Fontaine, 1890). Pinus vernonensis Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 316. Description —Cones elongate, conical, somewhat variable in size, averaging about 7 cm. in length by 1.8 cm. in diameter. Axis stout, 2 mm. to 3 mm. in diameter. Cone-scales triangular, relatively thin, thickened apically to form a rhomboidal boss with an elevated transverse ridge. A central umbilicus may represent the area of attachment of a short spine which had been worn away before fossilization. Length about 1.5 cm., greatest width about 0.8 cm. to 1.0 em., thickness 1 mm. to 2 mm.” The arrangement of the scales is a close spiral and in all of the cones collected or seen, numbering several score, none was found ex- panded, all having the scales closely appressed. This may indicate fossilization before maturity, since numbers of the cones retain their seeds, which is remarkable if the cones were shed in a ripe state. The seeds seem to be mature, however, and it is probable that the cones in this species had reached nearly or quite their full size when they were blown into some Lower Cretaceous stream and carried out and buried in the Patapsco estuaries. Each cone-scale subtends two seeds which are typically those of Pinus. The seeds are elliptical, 3 mm. to 5 mm. long with straight wings 5 mm. to 15 mm. high and not over 7 mm. wide, sides rather straight though somewhat curved on the outside, obtusely rounded apically. The single seed from Federal Hill represents the maximum of size as given above and is also rather more pointed than the specimens from the other localities. It was doubtfully described by Fontaine in his first monograph. More recently Professor Ward discovered seeds of Pinus at Mount Vernon, Virginia, and at Ft. Foote, Maryland. The former were described as Pinus vernonensis which now becomes the name of all the Pinus-like remains from the Patapsco formation. The latter specimens were described as a distinct species, Pinus schista, be- cause the wings are somewhat split. As the latter are identical with MaryLAND GEOLOGICAL SURVEY 403 the more complete remains from the other bank of the Potomac and as the different specimens are split to a varying degree and one speci- men is not split at all, it is quite obvious that the splitting is due entirely to trituration before fossilization. Recently the writer discovered abundant lignified cones associated with these seeds near Widewater, Virginia, and these cones were found in a number of instances to still contain some of their seeds which proved to be identical in every respect with the seeds previously described from the Patapsco formation. Having become familiar with the cones which bore the pine seeds it was found that the single cone described by Fontaine (loc. cit.), from Cecil County, Maryland, as identical with Araucarites virginicus was in reality a pine cone identical in every respect with the cones from near Widewater, Virginia. The seeds of Pinus vernonensis may be compared with those figured by Seward,’ from the Wealden of Bernissart, Belgium, as Pinites, cf. Solmst. In the National Museum collections a number of specimens of Wid- dringtonites ramosus are labelled Pinus vernonensis in Professor Fon- taine’s handwriting but there is no record in print of supposed foliage of this species, although there is a possibility that some of the following forms of Abietites may have such a relationship. Occurrence—Patapsco Formation. Mt. Vernon (seeds), near Widewater (cones and seeds), Virginia; Federal Hill (Baltimore) (seed), Ft. Foote, Prince George’s County (seeds), Muddy Creek, Cecil County - (cone), near Wellhams, Anne Arundel County (seeds), Maryland. Collections —U. 8. National Museum, Johns Hopkins University. Genus ABIETITES Hisinger [Lethea suecica, 1837, p. 110] Since its establishment by Hisinger in 1837 this genus has been a convenient and perhaps useful repository for fossils whose real or fancied ‘affinities were thought to suggest the modern Abietex. They 1Seward, La. Fl. Weal. de Bernissart, Mém. Musée Roy. d’Hist. Nat. de Belgique, Année 1900, p. 28, pl. iv, fig. 77. 404 SysTEMATIC PALEONTOLOGY have ranged in age from the Keuper to the Pliocene, the bulk coming from the Cretaceous, and consisting of obscure impressions of foliage and cones, none of which have any real biological value or present any definite clue to their true relationship. Professor Fontaine has in- cluded in this genus fossils from the Triassic of North Carolina and various indefinite remains from the Trinity Group of Texas, the Shasta Group of California, the Lakota formation of the Black Hills, and the Potomac Group of Maryland and Virginia. The latter he segregated into four species all of which were based upon obscure cone-impressions and none of which possess much specific value. When it is remembered what diverse appearances may be assumed by a single species of cone irrespective of individual variation and due to different stages of macera- tion before preservation, to differences in the matrix, and to differences in the direction and force of compression, it seems very probable that we are dealing with a single species of cone or at least not more than two, instead of the four which are in the literature relating to the Potomac formations. Similar forms from the English Wealden are described by Carruthers, Gardner, and Seward and referred to the comprehensive genus Pinites of Endlicher (1847). They are in all probability congeneric if not specifi- cally identical with Abietites macrocarpus Fontaine, whose generic and specific name is here retained since the writer wishes to avoid all unneces- sary changes and Endlicher’s Pinites is antedated anyway by the Pinites of Witham, 1833. In the French Neocomian also, cones of this char- acter are abundant, Cornuel (Bull. Soc. Géol. Fr. (ii), t. xxiii, 1866, pp. 658-673, pl. xii) describing five species from beds of this age and referring them to Pinus. His Pinus submarginata is especially sug- gestive of Abietites macrocarpus Fontaine, as are also some of the species of Pinus described by Coemans* from the Lower Cretaceous of Belgium and by Carruthers,” from the Gault of England. Finally the foliage from the Potomac beds which has been referred to Leptostrobus and Laricopsis is neither Leptostrobus nor related to Lariz, and since such *Coemans, E., Mém. Acad. Roy. Belg., tome xxxvi, 1867. * Carruthers, W., Geol. Mag., vol. iii, 1866, pp. 534-546, pl. xx, xxi. MARYLAND GEOLOGICAL SURVEY 405 - foliage in the English Wealden is in organic union with cones of the Abietites macrocarpus type, it seems eminently proper in the treatment of the American material to associate this type of foliage with the corresponding type of cone. ABIETITES MACROCARPUS Fontaine Plate LXVII, Figs. 1-4 Abietites macrocarpus Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 262, pl. exxxii, fig. 7. , Abietites ellipticus Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 263, pl. exxxii, figs. 8, 9; pl. exxxiii, figs. 2-4; pl. clxviii, fig. 8. Abietites angusticarpus Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, Pp. 263, pl. exxxiii, fig. 1. Abietites californicus Fontaine, 1894, in Diller and Stanton, Bull. Geol. Soc., Am., vol. v, 1894, p. 450 (nomen nudum). Abietites angusticarpus Font., 1899, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 671, pl. clxiii, fig. 14. Abietites angusticarpus Font., 1906, in Ward, Mon. U. S. Geol. Surv., vol. xIviii, 1905, pp. 528, 538, 556, 572, pl. exiv, fig. 10. Williamsonia ? Bibbinsi Ward, 1906, in Fontaine, in Ward, Mon. U. S. Geol. Surv., val. xlviii, 1905, p. 554, pl. exv, fig. 11. Abietites ellipticus Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 260, pl. Ixviii, fig. 14. Abietites macrocarpus Font., 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 261, 547, pl. Ixviii, figs. 15, 16; pl. exv, figs. 2, 3. Abietites macrocarpus Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 313. Description Large, stout cones, with a stout axis and numerous long, thin, imbricated, appressed scales. The various specimens vary considerably in length and appearance, and all are much macerated and poorly preserved. The author is unable to find good characters for the separation of the forms included in the foregoing synonymy, the sup- posed Williamsonia being nothing but a cone fragment vertically com- pressed as Prof. Ward surmised. Described originally from Fredericksburg and Dutch Gap, Virginia, it has since been identified in the Horsetown beds of California and the Fuson formation of the Black Hills, while a very similar cone- 1Seward, Wealden FI. pt. ii, 1895, p. 197, pl. xviii, figs. 2, 3; pl. xix, see especially pl. xviii, fig. 2. 406 SYSTEMATIC PALEONTOLOGY fragment has been described from the Trinity Group of Texas as Abie- tites Linkii (Roemer) Dunker. ‘These cones are comparable with a number of previously described species and they are especially close to Pinites Solmsi Seward from the English Wealden as the latter author has already pointed out. From the foliage preserved with the English cones, which is identical with what Professor Fontaine referred to as Leptostrobus, it is possible that the latter type of foliage was borne by the tree which furnished the cones described above. Occurrence.—Patuxent Formarion. Broad Creek, Maryland; Fredericksburg, Dutch Gap, Virginia. ARruNDEL Formarion. Arling- ton, near Lansdowne, Maryland. Parapsco Formation. Vinegar Hill (common), Ft. Foote, Maryland. Collections —U. 8. National Museum, Johns Hopkins University. ABIETITES MARYLANDICUS Fontaine Plate LXVII, Figs. 5, 6 Abietites marylandicus Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 549, pl. exv, figs. 4, 5. Abietites marylandicus Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 314. Description.—Obscure impression of a narrowly oblong cone about 15 mm. wide and about 4 cm. long, covered with closely placed, trans- versely elongated rhomboidal scars. The very stout peduncle might be taken to indicate a stout cone with thin scales of which only the basal portions were retained in the-fossil. The relation of this cone to the preceding species is altogether doubtful, it is retained in this genus since the preservation is so vague that any effort to determine its true affinity would be futile. In some respects it suggests the staminate cone of a cycad and it may also be compared with cones of the coniferous genus Geinitzia which are characteristié forms in the Albian, Cenomanian and Senonian. ‘There is also the possibility that the present material represents the poorly preserved cones of Pinus vernonensis Ward which is so common at MarYLAND GEOLOGICAL SURVEY 407 certain localities of this age. The specimen represented in fig. 5 is especially suggestive of such a relationship. Occurrence—Patapsco Formation. Vinegar Flill, Maryland Collection.—U. S. National Museum. ABIETITES LONGIFOLIUS (Fontaine), Berry Plate LXVII, Fig. 7 Leptostrobus longifolius Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 228, pl. ci, figs. 2, 3; pl. cii, figs. 1-4; pl. ciii, figs. 6-12; pl. civ, fig. 6. ies longifolius Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 671, pl. clxiii, fig. 15; pl. clxv, fig. 3. Leptostrobus longifolius Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, pp. 281, 481, 482, 491, 506, 528, 551, 557, pl. cx, fig. 11; pl. exvi, fig. 1. Abietites longifolius Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 315. Description.—Leaves long and narrow, needle-like, 10 to 15 cm. in length, aggregated in bundles. Bundles apparently borne on short shoots with many leaves in each bundle. No satisfactory venation can be made out. Fontaine describes a various number of veins in these forms but as nearly as can be determined these are simply folds due to compres- sion or the angles of the leaf. This species has a considerable geologic as well as geographic range having been recorded from the Kootanie formation of British Columbia and the Fuson formation of the Black Hills. In the Potomac Group it is of frequent occurrence and individually common being found in the oldest as well as the youngest beds. The remains are always poorly preserved and were evidently much macerated before fossilization. They are closely comparable with Pimites Solmsit Seward of the Wealden and with Pinus Peterseni Heer from the Kome beds of Greenland. They may also be compared with the genus Prepinus proposed by Professor Jeffrey for certain structural material from the Upper Creta- ceous. The type species of the latter genus came from the Raritan forma- tion of Staten Island, New York, and is described as showing centripetal xylem, although this feature is not clear in the figures of this species or 408 SysremMatTic PALEONTOLOGY in the slides kindly furnished the writer by Professor Jeffrey. A single additional species has more recently been described by Stopes* from the Upper Cretaceous of Japan and this latter is said to lack centrip- etal xylem, a feature in any case of considerably less theoretic impor- tance than is assigned to it by Professor Jeffrey. Still more recently the latter author has described another species from the Magothy for- mation of Marthas Vineyard.’ The genus Leptostrobus was proposed by Heer”™ in 1876 for certain Siberian Jurassic cones, although in 1880 remains of foliage were also correlated with these cones.” Five species in all were described. ‘The age of the containing beds is Oolitic. Subsequently this generic name was utilized by Ward and Fontaine for a considerable number of American Jurassic and Cretaceous species based on an assortment of probably unrelated vegetative twigs, supposed cones, and seeds or fruits. Occurrence—PATUXENT Formation. Fredericksburg, Potomac Run and Dutch Gap, Virginia. Parapsco Formation. Brooke, 72-mile post Mt. Vernon and Hell Hole, Virginia; Ft. Foote, Vinegar Hill (very common), and Federal Hill (Baltimore), Maryland. Collection—U. §. National Museum. ABIETITES FOLIOSUS (Fontaine) Berry Leptostrobus foliosus Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 230, pl. ci, fig. 4; pl. ciii, fig. 5; pl. civ, fig. 1. Laricopsis longifolia Fontaine, 1890, Ibid., p. 233, pl. cii, figs. 7, 8; pl. ciii, figs. 2, 3; pl. clxv, fig. 4; pl. clxviii, figs. 5, 6. (?) Laricopsis longifolia Fontaine, 1893, Proc. U. S. Nat. Museum, vol. xvi, p. 268, pl. xxxvi, fig. 9. Leptostrobus foliosus Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 482. Laricopsis longifolia Fontaine, 1906, Ibid., p. 312, pl. lxxiii, figs. 11, 14. Abietites foliosus Berry, Proc. U. 8S. Natl. Mus., vol. xl, p. 314. *Stopes, Annals of Bot., vol. xxiv, 1910, pp. 395-402, pls. xxvii, xxviii. ? Jeffrey, Proc. Bost. Soc. Nat. Hist., vol. xxxiv, 1910, pp. 333-338, pl. xxxiii. * Heer, Fl. Foss. Arct., Band iv, Abt. ii, 1876, p. 72. ‘Heer, Ibid., Band vi, Abth. i, 1880, p. 23. MARYLAND GEOLOGICAL SURVEY 409 Description.—Leaves long and slender, .5 to 1.0 mm. in width, full length not seen, at least several centimeters, much crowded, seen to be in bundles where the preservation is fairly good. This is clearly distinct from the preceding species and less common. It is not fully characterized because of the poorness of preservation as evinced by the fact that the leaves are detached in a majority of the specimens collected. The forms which were the basis for Laricopsis longifolia Fontaine have been united with this species since they are indistinguishable and probably identical in character. This species occurs at the oldest and youngest horizons in the Virginia Potomac and it has also been recorded from the Kootanie formation of Montana. The fragment from the Trinity beds of Texas which Professor Fontaine identifies with such certainty is, in the writer’s judgment, absolutely untrustworthy. Occurrence—PattxENt Formation. Dutch Gap and immediate vicinity, Virginia. Parapsco ForMATiIoNn. Brooke, Virginia. Collection—U. 8. National Museum. Genus LARICOPSIS Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 232] This genus received the following diagnosis by its describer: “Trees or shrubs, with the penultimate twigs sending off alternately in the same plane ultimate branches; leaves thin, narrow, and thread- like, attached by the entire base either in bundles at the same point on the stem or scattered singly on its surface, both on the same stem, very deciduous, the leaf-bundles leaving small scars. Nerves not made out with certainty, but apparently one for each leaf. “This genus is nearer to Laria than to any other known plant, and the the resemblance is sufficiently great to render it possible that it may be the ancestor of this genus. It should be noted that the young shoots of Larix often have the leaves scattered singly as they occur in this genus, and it is probable that the immature portions of Larix approach the ancestral forms more nearly than the mature portions do. In these 410 SyYsTEMATIC PALEONTOLOGY specimens also the leaves appear most often to be attached laterally to the stems as now preserved, while no doubt they were originally scat- tered around the stem. This appearance, as in the case of Leptostrobus, is doubtless due to the accidents of preservation. No nerves could be made out with certainty. The leaves are very narrow, being sometimes like hairs.” The unsatisfactory nature of the material upon which this genus is founded renders any extended comment superfluous. As here under- stood it includes but a single species which is confined to the Patuxent formation of Virginia. That there is any relation to the modern genus Larix is doubtful and it. seems probable that Laricopsis will eventually be correlated with those Cretaceous remains here referred to the genus Abietites. The fancied resemblance to Larix was based on the grouping of the slender leaves and their deciduous nature, although the criteria for determining such a habit in the case of much macerated coniferous fossils are not altogether obvious to the writer. LaRIcopsis ANGUSTIFOLIA Fontaine Laricopsis angustifolia Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 233, pl. cii, figs. 9, 10; pl. ciii, figs. 1, 4. Laricopsis brevifolia Fontaine, 1890, Ibid., p. 234, pl. cii, figs. 5, 6. Description.—T wigs slender. Leaves slender, scattered singly or in fascicles, thin and flat, ranging in length from 1 em. to 3 em. Obviously the variation among the different examples of these rare twigs is not sufficient to serve as a basis for two species as described by Fontaine, and as the remains come from identical outcrops they are here considered as slight variants of a single species; the apparent minute differences noted by their original describer being due to differences of preservation. They are an altogether negligible element in the Potomac flora at best. Occurrence.—PatTUXENT Formation. Dutch Gap and Trents Reach, Virginia. Collection —U. 8. National Museum. MARYLAND GEOLOGICAL SURVEY 411 Genus CEDRUS Miller [Gard. Dict., ed. ili, 1737] The modern cedars number three species of northern Africa, southern Asia, the Himalayas, and the Orient. Evidence that the genus was much more widespread in the past is furnished by a considerable amount of fossil evidence. Cedars undoubtedly made their appearance at least as far back as the Lower Cretaceous, no less than three species founded upon cones occurring in the Albian of England, Belgium, and. France. These records are substantiated by the association of the cones in the latter country with fossil wood showing structure and described as various species of Cedroxylon by Fliche* and Lignier.” Fossil wood is also described by the former author from the somewhat older Barremian deposits of France (Haute-Marne*) » while Schenk and Nathorst refer two of Cramer’s species of Pinites from the Upper Jurassic of Spitz- bergen to Cedroxylon.* The genus has not been previously recorded from America. The toxonomy of Mesozoic cones is in such a deplorably tangled state that it is difficult or altogether impossible to infer the true affinities of a large number of the various species of Pinites, Abietites, Strobilites, Conites, etc. Ceprus Lerr (Fontaine) Berry Plate LXXVII, Figs. 4, 4a Cedar cone Bibbins, Johns Hopkins Univ. Circ., vol. xv, 1895, p. 19, fig. F. Pinites Leei Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 570, pl. cxix, figs. 6, 7. Deseription.—Cone small (possibly unripe), 4 cm. long by 2.x 1.5 cm. in diameter, considerably distorted by the movement of the enclosing clay so that the scales on one side appear thin, while the reversed move- ment gives those on the opposite side the appearance of being tipped by 1Wliche, Etudes sur la Flore Fossile de l’Argonne, 1896, p. 134, pl. xv, figs. 1, 2. 2 Lignier, Mém. Soc. Linn. Normandie, tome xxii, 1907, p. 263, pl. xviii, figs. 15-17; pl. xxi, fig. 66; pl. xxii, fig. 72; pl. xxiii, fig. 87. ’Fliche, Bull. Soc. Sci. Nancy, 1900, p. 16, pl. ii, fig. 1. 4 Nathorst, Kgl. Svensk. Vetensk.-Akad. Handl., Bd. xxx, 1897, p. 42. 412 SYSTEMATIC PALEONTOLOGY a short and wide umbo almost sufficiently developed to suggest the genus Sequoia, but due entirely to the pressure and the movement of the matrix in a direction toward the base of the cone as can be readily seen by the intermediate scales. Scales in a close spiral, imbricated, rather thin, perhaps, .5 mm. in thickness, strongly striated longitudinally, very broad, the distance around the cone being occupied by slightly over 3 scales; and, as the circumference of the fossil is 5.7 cm. it would make each fully developed scale about 1.7 cm. in width, broadly rounded apically and apparently slightly thicker at the tip than elsewhere, exposed for a height of about 3 mm. This species is based upon a single specimen, which is so admirably preserved, however, that in a footnote to the original description Profes- sor Ward raises the question whether it may not be a Pleistocene cone of Abies or Picea, preserved in some Quaternary pocket of the Potomac surface. Mr. Bibbins who obtained it from Mr. John W. Lee, the original discoverer, is positive that it comes from Potomac strata, and the condition of the specimen tends to substantiate this view since it is thoroughly altered to a jet. Picea does not have such wide scales and those of Abies are deciduous. Professor Fontaine referred this cone to the genus Pinites, presumably the Pinites of Endlicher 1847 since it resembles somewhat the English Wealden forms which were referred to that genus by Carruthers, Gard- ner, and Seward. The genus Pinites, which is used by Seward in his Wealden Flora in much the same way that the writer uses Abietites for imperfect cones which resemble those of Abies or the Strobus section of Pinus, is somewhat misleading in the present case since the cone in question is to all appearances referable to Cedrus, the modern species of which have long since been segregated from the old genus Pinus. The genus Cedrus*is represented in the Cretaceous by at least three species of Albian age from various European localities, those from France being associated with wood of the Cedrozylon type. Except for its smaller size, which may be due to immaturity, the Potomac cone is very close to those of these European species and to those of the modern species of Cedrus. MaryLAND GEOLOGICAL SURVEY 413 The Cedrus lotharingica which Cornuel (Bull. Soc. Géol. Fr. (iil), t. x, 1882, p. 262, pl. vii, figs. 2, 3) describes from the lower Gault of Houpette (Meuse), France, is strikingly similar to the Potomac form. This species was afterward united by Fliche loc. cit. with the larger but otherwise similar cones which are widespread in the Albian of France and England under the name of Cedrus oblonga (L. and H.). Occurrence.—ARUNDEL Formation. Union Tunnel, near Aisquith St., 35 feet below the surface, Baltimore, Maryland. Collection.—Johns Hopkins University. Genus CUPRESSINOXYLON ! Goeppert [Mon. Foss. Conif., 1850, p. 196] This rather comprehensive genus is defined as follows by its original describer : “Truncorum structura fere Cupressinearum viventium. Trunci ipsi e cortice, ligno et medulla magis minusve centrali formati. Corticis pars fibrosa cellulis quadrangulis periphericis, lignum e stratis concen- tricis angustis distinctis, strati zona exteriore plerumque angusta e cellulis pachytichis compressa, interiore multo latiore e vasis leptotichis formata, medulla e ipsa cellulis paucioribus pachytichis composita. Cellule ligni prosenchymatose, porose ductibus resiniferis simplicibus interjectis. Pori rotundi in simplici, in truncis annosioribus quoque duplici interdum tri vel quadruplici serie in eodem plano horizontali justapositi, in iis plerumque tantum cellularum parietibus, qui sibi oppo- siti et radiorum medullarium paralleli sunt vel in parietibus radiis medullaribus obversis interdum nonnulli vel etiam plurimi tamen minores in omnibus inveniuntur. Radii medullares similares minores simplici cellularum parenchymatosarum porosarum serie. Parietes earum supe- riores et inferiores poris minutis, laterales majoribus instructi. Ductus resiniferi plerumque simplices cellulis elongatis subquadrangulis super- positis formati inter ligni cellulas imprimus angustiores inveniuntur.” 1This generic name is spelled in various ways, the present usage being that of Goeppert which not only has priority but is etymologically correct, the root being derived from the subfamily name Cupressinee. 414 SysTEMATIC PALEONTOLOGY Goeppert’s work was ably supplemented by that of Kraus, who points out that the usual specific characters used by students of vascular anatomy such as the breadth of the annual ring, width of the cell-lumina, thickness of the cell-wall, number of rows of pits on the radial walls of the tracheids, height of the medullary rays and their frequency, can only be used with the most extreme caution on account of the individual variation of these parts in different parts of the same plant or on different individuals of the same species. Krause’s diagnosis of Cupress- imozylon as given by Schimper ? is as follows: “Qignum stratis concentricis distinctis, angustis; cellulis prosen- chymatosis porosis, poris magnis, rotundis, uni-vel pluriserialibus, oppo- sitis; cellulis resiniferis creberrimis, ductibus resiniferis nullis, radiis medullaribus simplicibus.” More modern studies have emphasized the uncertainties of vascular anatomy as indicative of exact relationship.” A large number of species, so-called, have been described, Schimper in 1870 listing 41,* and many more have been described since Schimper’s list was prepared. These range in age from the Lower Cretaceous to the Pliocene. The fossil wood and lignite of the Potomac beds was made the sub- ject of a monograph by Knowlton in 1889° which remains our only source of knowledge of the anatomy of the Potomac plgnts. A chapter is devoted to the very interesting historical development of the study of fossil wood which strangely enough, considering its abundance, is not mentioned by any of the ancients, the first authentic record being that of Albertus Magnus about the middle of the 13th century.’ Both lignite and petrified wood, either silicified or ferruginized, are +See Solms-Laubach, Fossil Botany, 1891, pp. 81-83. ? Schimper, Pal. Végét., tome ii, 1870, p. 374. 3 Gothan, Zur Anatomie lebender und fossiler Gymnospermen-Ho6lzer, Abh. k. preuss. geol. Landes, N. F., Heft xliv, 1905, pp. 101-103. * Schimper, loc. cit., pp. 374-377. 5’ Knowlton, Bull. U. S. Geol. Survey, No. 56, 1889. ®Beati Alberti Magni de Mineralibus Tractatus I, Caput VII, Opera, Lug- duni, 1651, vol. ii, p. 216. MARYLAND GEOLOGICAL SURVEY 415 common at most horizons in the Potomac beds, but very little effort has been devoted ‘to their collection or study. The lignites as far as they have been examined are coniferous but so much distorted by pressure snd by decay before fossilization as to be of but little scientific value. The silicified materials while in a somewhat better state of preservation leave much to be desired. Of a large number of such sections in the hands of the writer only a very few are sufficiently well preserved to be determinable. The ease with which fragments of silicified wood may be reworked from formation to formation also minimizes their strati- graphic and phylohistorical value. The following two species have been described from the Maryland area by Knowlton.’ CUPRESSINOXYLON Warpi Knowlton Plate LXVITII, Figs. 1-6, Plate LXIX, Figs. 7, 8 Cupressinozylon Wardi Knowlton, 1889, Bull. U. S. Geol. Survey, No. 56, p. 48, pl. iv, figs. 1-4; pl. v, figs. 1, 2. Description —*“ Annual ring distinct, moderately broad; tracheids medium in size, the radial walls bearing one, rarely two, rows of bordered pits; medullary rays two cells broad and from one to thirty- five cells high; resin ducts simple, not numerous. “This species is represented by specimens from the localities which have been designed by the letters A and B, respectively. “A. Several small fragments collected by W J McGee in a cut on the Washington Branch of the Baltimore and Ohio Railroad about half way between Montello and Rives Station, D. C. The largest piece is only 8 em. long, 6 cm. wide, and 1 cm. thick, and the others are much smaller. They are all very poorly preserved, and the structure can be made out only in a few favored spots. “B. A small piece, hardly 5 em. square, collected by Lester F. Ward from Freestone Cut, on the Neabsco Creek, Virginia. Like the other specimens this is very badly preserved, and the structure has entirely disappeared in many places. 1 Knowlton, 1889, loc. cit. 27 416 SYSTEMATIC PALEONTOLOGY “ Microscopic analysis.—Transverse section: The fragments are all too small and too poorly preserved to show the annual rings to the naked eye, but under the microscope they are observed to be tolerably distinct. The ring of fall wood consists of from three to six or eight compressed cells in each radial row. The spring wood contains some very large cells, with a diameter in some instances of .062 mm. The number of cells in each row of tracheids varies according to the width of the annual ring, there being frequently as many as one hundred.’ Large intercellular spaces occur particularly where additional rows of tracheids have been introduced. “ Radial section.—In this section the tracheids are shown to be provided with one row; or, in some rare instances, with two longitudinal rows of bordered pits. They occupy the center of the cell and are close to- gether, almost touching in some cases. The larger have a diameter of .020 mm., and the smaller a diameter of .015 mm. The medullary rays consist of typical parenchymatous tissue. The individual cells are short, covering the width of from four to eight tracheids. I have not been able to detect markings on the walls of the rays, but this may be on account of the poor state of preservation of the specimens. The resin ducts are not numerous. They are of nearly the same size and shape as the tracheids, and in fact look very much like tracheids with transverse partitions. They are almost always empty. “ Tangential section.—The tracheids are not provided with pits on the tangential walls, or at least none have been detected. The medullary rays in many cases are two cells broad, and, as above indicated, from one to thirty-five cells high. The. individual cells of the rays have a diameter of from .017 mm. to .030 mm.”—Knowlton, 1889. Additional and somewhat better preserved material enables the writer to add one or two features to the foregoing description. It may be noted that the so-called annual ring is not distinct in the present section, where, over a distance of 2 cm., there is but a single zone of smaller cells. This is only three or four cells wide and not at all regular. It undoubtedly denotes a slackening of vitality but hardly merits the term of fall wood. The radial rows of tracheids are somewhat irregular and MARYLAND GEOLOGICAL SURVEY 417 those of the same age are often quite variable in size. The bordered pits were not observed except in a single row and are not especially close together. In the radial section the ray pores can occasionally be made out. They are small and circular and not more than two were observed in the width of a wood cell. There is great variability in the rays, which may consist of a single or but two cells, or a ray may be made up of twenty or thirty cells in a single row, or a high ray may be double at either end or merely in the middle, or small rays only 4 or 5 cells high may be double throughout. Occurrence.—PatuxEnNt Formation. Clifton (Baltimore), Mary- land; Near Montello, District of Columbia, Neabsco Creek, Virginia. Collections —U. 8. National Museum, Johns Hopkins University. CUPRESSINOXYLON McGzrxI Knowlton Plate LXIX, Figs. 1-6 Cupressinozylon McGeei Knowlton, 1889, Bull. U. S. Geol. Survey, No. 56, p. 46, pl. ii, fig. 5; pl. iii, figs. 1-5. Description Annual ring very distinct, from 2 mm. to 4.5 mm. broad; tracheids remarkably large, thick walled, closely covered with from one to three rows of large bordered pits on the radial walls and a few scattered ones on the tangential walls; medullary rays simple, from 2 to 49 cells high, covered on the lateral walls with numerous oblong pores; resin ducts simple, numerous, composed of a chain of thin walled cells. “The type of this species was collected by W J McGee of the U. 8. Geological Survey, from excavations made for the new reservoir of the water-works extension, Washington, D. C. It had originally a length of nearly forty feet and a diameter of almost two feet. It was somewhat flattened by pressure, the shorter diameter being considerably less than the longer. The trunk was exposed at a depth of about twenty feet below the surface, and must have belonged originally to a tree of large size. To the naked eye the annual rings are very indistinct. The medullary rays, however, are easily observed and are seen to pursue a very tortuous course, due, in part at least, to the dislocation caused 418 Systematic PALEONTOLOGY by the pressure to which it had been subjected. The- bark was not preserved in any of the pieces examined. “ Microscopic analysis—Transverse section: This section shows the tracheids to be arranged in strict radial rows, and also indicates their great size. The annual ring, as above stated, is broad, consisting in some cases of as many as fifty or sixty of the larger and from ten to sixteen of the smaller, thick-walled cells.. The larger cells are mostly quad- rangular in outline and have a diameter in some instances of .080 mm., the average being about .068 mm. The cells of the fall wood have very thick walls and are much flattened. Intercellular spaces are frequently observed, particularly where additional rows of tracheids have been intercalated (pl. Ixix, fig. 1). The medullary rays are moderately numerous. “ Radial section.—The large size of the tracheids is very clearly shown in this section, most of which is made up of summer wood. The tracheids in the fall wood are, of course, much smaller and are covered with but a single row of pits. The bordered pits are very close together on the summer wood and are always in two and in some exceptionally large cells in three rows. They are also, very large, the outer circle having a diameter of from .020 mm. to .025 mm., and the inner of from .005 mm. to .008 mm. The walls of the medullary rays are marked by large oval pores, from one to three of which occupy the width of a single wood cell. These pores are about .015 mm. in length and .010 mm. in the short diameter. The resin ducts consist of a chain of short, small, thin-walled cells, which now contain a small quantity of granular matter, representing probably the drops of resin. The individual cells have a length of from .12 mm. to .25 mm., and a diameter of about .05 mm., slightly less, it will be observed, than the tracheids among which they run. “ Tangential section.—_The medullary rays are always simple; that is, they consist of but a single row of cells, which varies. from 2 to 49 cells in height. The tracheids are provided on the tangential walls with a few scattered bordered pits. These have a diameter of from .016 mm. to .021 mm.”—Knowlton, 1889. MARYLAND GEOLOGICAL SURVEY 419 It is of interest to note that Gothan* has described wood extremely close to, if not identival with this species from the supposed Upper Jurassic (Portlandian ?) of King Charles Land. Occurrence.—PaTUXENT Formation. New Reservoir, District of Columbia. Collection —U. 8. National Museum. Subfamily CUPRESSINEAE Genus FRENELOPSIS Schenk [Paleontographica, Band xix, 1869, p. 13] Shrubs or trees with cylindrical jointed monopodial stems and branches, the latter of which may be alternate, apparently in a single plane, or whorled, often of large size, stems up to 5 cm. in diameter having been found in the Virginia area. Leaves much reduced, somewhat variable in outline, in general triangular with a broad base and an acute apex, squamiform, appressed, one to four in number at the nodes, decussate. Internodes variable in length but longer in the apparently annual shoots which were more or less deciduous and functioned as leaves, since the fine longitudinal striae with which their surface is ornamented turn out in certain of the species which have been examined microscopically to be rows of stomata. These stomata have been described for Frenelopsis Hoheneggeri by Zeiller* and for Frenelopsis bohemica by Velenovsky." They consist in the foregoing species of four cells although sometimes five or even six may be present. They are symmetri- cally arranged, the opening between them being in the form of a narrow- rayed star. According to the former author they ally these forms with the existing species of Callitiis and Libocedrus and effectuaily disprove Heer’s contention that this curious genus is a member of the Gnetales allied to Ephedra. 1Gothan, Die Fossilen Hélzer von Koénig-Karls-Land, Kgl. Svenska Vetens.- Akad. Handl., Band xlii, No. 10, 1907. 2 Zeiller, Obs. sur quelques cuticules fossiles, Ann. sci. nat., 6e sér., Bot., t. xiii, p. 231, pl. xi, 1882; Eléments de Paléobotanique, 1900, p. 274, fig. 196. 8 Velenovsky, Ueber einige neue Pflanzenformen der béhemischen Kreide- formation, Sitz. k. béhm. Gesel. Wiss. Prag., 1888, p. 590, figs. 1-3, 10. 420 SystreMATIO PALEONTOLOGY The epidermis is made up of small rectangular thick walled cells and is very coriaceous, as are apparently the cortical tissues, which serves to account for the preservation of the twigs in such abundance where the materials have been much macerated as at Plaster Bluff on the Little Missouri River, Arkansas. This genus was founded by Schenk upon abundant material from the Wernsdorferschichten, with Thuttes Hoheneggeri of Ettings, as the type and only species. This was, he says, the most abundant fossil in those beds in which it occurs, and it received a careful and elaborate treatment at his hands. This species has subsequently been recognized in the Kome beds of Greenland, the Trinity of the Texas region, the Raritan and Magothy formations of New Jersey and the Turonian of Bagnols, France. In 1880 Hosius and van der Marck described a rather illy-defined species, F. Kénigti, from the Senonian of Westphalia * and the next year Heer * described an additional species, F’. occidentalis from Portugal which Saporta has shown” ranges from the Urgonian of Cercal through the Albian of Nazareth into the Cenomanian of Alcantara and Padrao. The latter author also describes an additional species, F. leptoclada” which is confined to the Lower Cretaceous of Portugal (Neocomian-Aptian). In 1889 Velenovsky described the Bohemian form F. bohemica from the Cenomanian of that country (loc. cit.) and the next year Fontaine described the two species fromthe Potomac Group (loc. cit.) the same author three years later founding a third species, F. varians upon material from the Trinity Group of Texas.’ Newberry in 1896 described the ninth species F. gracilis’ which is a very abundant type in the Raritan and Magothy formations of the Coastal Plain and which has recently been shown by Hollick and Jeffrey to be referable. to a distinct genus. * Paleont., vol. xxvi, 1880, pp. 132, 181, pl. xxxvii, fig. 148. *Cont. Foss. FI. Port., 1881, p. 21, pl. xii, figs. 3b, 4-7. * FL Foss. Port., 1894, pp. 139, 199, 214, pl. xxvi, fig. 16; pl. xxxvi, figs. 1, 2; pl. xxxviii, figs. 2, 3; pl. xxxix, fig. 20. “Loc cit., pp. 109, 113, pl. xix, fig. 18; pl. xxi, figs. 9-11. * Proc. U. S. Natl. Mus., vol. xvi, 1898, p. 278, pl. xl, figs. 1, 2; pl. xli, figs. 1-3a. ° Fl. Amboy Clays, 1896, p. 59, pl. xii, figs. 1-3a. Marytanp GroLogicaL SURVEY 421 Although fruiting specimens have not been found, the position of the genus in the Cupressiner based as it is upon similarity in habit, form, and stomatal characters, is not disputed at the present time although formerly Heer argued for an affinity with Ephedra. Named originally for its resemblance to the living species of Frenela of the Australian region, we find the latest treatment of the modern Cupressinew, that by Eichler in Engler and Prantl’s Naturlichen Pflanzenfamilien (1889), makes Frenela a subgenus of Callitris Vent., the latter being divided into four subgenera as follows: Octoclinis F. v. Mill. (Frenela Bentham) with eight scales to the cones and a single species inhabiting Australia. Hexaclinis (Frenela Mirbel) with six scales, 3 large and 3 small, and nine species of Australia and New Caledonia. Pachylepis Brongn. (Widdringtonia Endl.) with thick woody cones of four subequal scales and having three or four species of South Africa and Madagascar. Eucallitris Brongn. (Tetraclinis) with four scales to the cones and a single species of Northern Africa. However admirable this arrangement may be when only the living species are considered, it will not answer for the fossil forms and paleo- botanists quite rightly maintain the various genera Frenelites, Wid- dringtonia, Widdringtonites, Callitris, etc., ranging in age from the older Mesozoic through the Tertiary and abundantly fortified by fruiting specimens. Fossil fruits of still other species and perhaps genera occur in the late Tertiaries of Australia, the weight of the evidence showing that this type was considerably more varied in the past, the existing forms being isolated remnants of a once almost world-wide distribution. Within the Potomac Group Frenelopsis ramosissima ranges from the bottom to the top while F. parceramosa appears to be confined to the later beds serving by its resemblance to F’. Hoheneggeri to connect them with the overlying Raritan formation. The genus is not recorded from the English Wealden although certain poorly preserved remains which fail to show joints or leaves but seem to be similar in habit are described by Seward as a new genus and 422 SYSTEMATIC PALEONTOLOGY species, Becklesia anomala. These, as their author points out, show considerable resemblance to some of the more poorly preserved specimens of Frenelopsis Hoheneggeri figured by Schenk from the Wernsdorfer schichten. Nathorst in a recent paper upon some fossil plants collected by Felix from the Neocomian of Tlaxiaco, Mexico,’ establishes a new genus for somewhat similar remains which he calls Pseudofrenelopsis on the ground that the specimens are not truly jointed. To this genus he would refer Fontaine’s species and in this he is followed by Seward (Joc. cit. p. 181). It is difficult to see the basis for Nathorst’s proposals since the Mexican remains appear to differ from those found in Maryland, Virginia, or Texas, and since these latter are all jointed and therefore exhibit the characters of true species of Frenelopsis according to Nathorst’s own definition. FRENELOPSIS RAMOSISSIMA Fontaine Plates LX XI, LXXII Frenelopsis ramosissima Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 215, pls. xcv-xcix; pl. c, figs. 1-3; pl. ci, fig. 1. Frenelopsis ramosissima Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., ‘vol. xlviii, 1905, pp. 504, 512, pl. exi, fig. 8. Frenelopsis ramosissima Berry, 1910, Botanical Gaz., vol. 1, pp. 305-309, tf. 1, 2. Description.—Stems sometimes of large size, the branches sometimes alternate but usually crowded in whorls at the nodes with three to five branches to the whorl. Internodes usually short, as are the ultimate © branches. Jointing not visible in the larger stems. Epidermis durable, longitudinally striated. Leaves in whorls of three at the nodes, decussate in outline, acute, closely appressed, becoming somewhat variable on the larger stems. Clusters of abortive branches or buds occur and are figured by Fontaine. Seward, Wealden FI1., pt. i, 1894, p. 179, pl. xiv. * Nathorst, Pflanzenreste aus dem Neocom von Tilaxiaco in Beitr. z. Geol. u. Paleont. d. Repub. Mexico, von J. Felix u. H. Lenk, ii Theil, Leipzig, 1893, pp. 51-54 (see p. 52, figs. 6-9). MaryLanp GEoLogicaL SURVEY 423 The epidermal cells are very small, the largest not exceeding 0.025 mm. in diameter, and the average being about half this size., They are roughly rectangular in shape and have very thick walls. Their most curious feature, one not observed in any other species of this genus, is the presence of minute, usually curved, spinelike outgrowths of large numbers of the epidermal cells. These protuberances vary in prominence 4 men 1.10 Fie. 14.—View of a preparation of the epidermis of Frenelopsis ramosissima. from blunt papille of various heights to pointed spines 0.025 mm. in length. These are not present on all of the epidermal cells, and some preparations of the epidermis are apparently entirely smooth. Fig. 14 shows a characteristic bit of the epidermis dotted with these spines. Some of the spines, probably all of them, have a central cavity opening into the interior of the epidermal cell, which they surmount, as is shown in one of the individual spines figured. The second and third single spines figured show irregular cavities toward the apex which 424 SYSTEMATIC PALEONTOLOGY are apparently cut off from the cell cavity, and the third spine figured gives a good idea of the papillose character of those adjacent cells in which these processes are not prominently developed. In the area included in fig. 14 are three of the curious stomatal open- ings which apparently characterize the genus Frenelopsis. These are circular in outline and about 0.03 mm. in diameter. They are very numerous, but whether they are localized on certain portions of the branches which perform the functions of leaves in this genus, or whether they are uniformly distributed on the annual shoots, could not be deter- mined. They consist of five or six guard cells arranged around the central stomatal opening. These cells are much thinner-walled than the epidermal cells. In form they are relatively slender distad and broad proximad. As viewed through the microscope, they are darker colored around the stomatal opening and peripherally they are lighter. Since structural material is not available, their exact attitude is made ‘out with difficulty. Their outer centrally directed ends come into focus at about the same time as do the outer ends of the longer spinelike proc- esses, or very soon after, while their inner broad ends are visible after the epidermal cells have gone out of focus; hence it is obvious that they are inclined toward each other and project outward for a con- siderable distance from beneath the surrounding epidermal cells. In their more essential characters they agree with the stomata as described by Zeiller for #: Hoheneggeri and by Velenovsky for F. bohemica. Just what were the physiological factors responsible for the great reduction of the leaves and the assumption of the photosynthetic processes by the branches in Frenelopsis it is difficult to imagine. Such features are usually associated with peculiarities of climate and habitat, and suggest strong insolation and lack of humidity; but such conditions are not suggested by the other members of the flora associated with Frenelopsis, since with the Potomac species are found large numbers of ferns, many of them apparently tree ferns with decompound fronds a meter or more across, and large numbers of cycads of various genera and large size; while in the latest beds in which F. ramosissima occurs there are considerable numbers of dicotyledonous leaves, some of which MaryYLAND GEOLoGicaL SURVEY 425 are allied with genera which in the modern flora are confined to tropical areas where the humidity is high and the rainfall heavy. It is possible that these peculiar features in the Cretaceous species of Frenelopsis were inherited from Triassic ancestors which acquired them during these portions of the Triassic when the climate was extremely arid, as we know it was from physical as well as paleontological criteria. This species, which is exceedingly abundant in the oldest Potomac at Fredericksburg, Virginia, occurs sparingly at higher horizons both in that State and in Maryland. It may be distinguished from the following species and from Frenelopsis Hoheneggeri by the short branches, their crowded habit, and the short internodes. The latter species is described as having the leaves in pairs and opposite while in F'. ramosissima they are in whorls of three, but this can have but little significance since in the living forms the leaves normally in threes occur singly, in pairs, or in fours. The following species often shows but a single leaf at the nodes while F’. leptoclada Sap. has the leaves either opposite or in fours. Perhaps the most nearly related species is Frenelopsis occidentalis Heer of the Barremian, Albian and Cenomanian of Portugal, but this is abundantly distinct, in fact the majority of species of this genus taken as a whole constitute a group of forms closely related to the type species with which, some of them may even be identical, while F. ramosissima stands by itself as a markedly distinct type. Occurrence.—PatuxENT Formation. Fredericksburg, Virginia. Parapsco Formation. Federal Hill (Baltimore), Maryland; Chinkapin Hollow, Hell Hole (?), Virginia. Collections.—U. 8S. National Museum, Johns Hopkins University. FRENELOPSIS PARCERAMOSA Fontaine Plate LXX, Figs. 1-5 Frenelopsis parceramosa Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 218, pl. cxi, figs. 1-5; pl. cxii, figs. 1-5; pl. clxviii, fig. 1. Frenelopsis parceramosa Fontaine, 1906, in Ward, Mon. U. 8. Geol. Surv., vol. xlviii, 1905, pp. 544, 584. . 426 SYSTEMATIC PALEONTOLOGY Description—Branches larger in size than in the preceding species, more remote and much longer, but with the same short internodes, constricted at the nodes. Epidermis persistent, the longitudinal rows of tubercles produced by the stomata more prominent than in the pre- ceding. Leaves very short and broadly triangular, closely appressed, often entirely suppressed and never more than a single one observed at a node. Ultimate branches not only deciduous but prone to break up at the joints so that the materials preserved are usually poor. The branches could not have been very woody since in the fossils they are generally pressed flat and ribbon-like. Fontaine speaks of them as succulent, which may or may not have been the case, the mere fact of their being flattened is hardly an argument in favor of such a condition. This species more closely resembles F. H. oheneggeri in its long cylin- drical branches, differing in its shorter internodes and in the number of leaves. Both are variable characters, however, since on single specimens so identified by Heer from the Kome beds we find a variation of length of the internodes of from 1 cm. to 2.2 em. and among the various frag- ments figured some internodes are only 3 or 4 mm. in length while others are 2.4 cm. and a large number are about 1 cm. Frenelopsis parceramosa is also closely related if not identical with F. varians described by Fontaine from the Trinity Group of Texas and Arkansas and also shows considerable resemblance to the European species of this genus. Its occurrence in Virginia is very local and but few specimens have been found in Maryland. Occurrence.—PatvUxENT Formation. Trents Reach, Virginia. Arun- DEL ForMATION. Hanover, Howard Brown estate (?), Maryland. Collection—U. 8. National Museum. Genus WIDDRINGTONITES Endlicher [Synop. Conif., 1847, p. 271] The genus Widdringtonites was established in 1847 by Endlicher with Thuites gramineus Sternberg* from the Tertiary of Perutz, Bohemia, 1 Sternberg, Fl. Vorwelt, Tentamen, 1825, p. xxxviii, pl. xxxv, fig. 4. MaryLaNnp GEOLOGICAL SURVEY 427 as the type. This he named Widdringtonites Ungeri including in its synonymy Juniperttes baccifera Unger, Thuia graminea Brongn., and Muscites Stolzii Sternberg. Three additional species were listed, one from the Cretaceous, one from the Wealden, and one from the Lias. His characterization of the genus was as follows: “Folia spiraliter inserta, pleraque squameformia adpressa. Strobilus globosus, valvatus.” There are perhaps a score of species referred to this genus at the present time ranging in age from the Triassic to the Miocene. It has d Fitzroya Le on Fic. 15.—Sketch map of the world showing the segregation of the existing Actinostrobine and the Mesozoic occurrences of Frenelopsis and Widdring- tonites. Circles indicate Frenelopsis and crosses indicate Widdringtonites. been commonly used for foliar specimens which resembled the «living forms but which lacked the certainty furnished by associated cones. These are known, however, in a large number of species, many of which, especially those of Tertiary age, are now referred directly to the genus Widdringtonia. Although fruiting specimens of Widdringtonites ramosus (Font.) are unknown, its immediate successor Widdringtonites Reichii (Httings.) Heer of the Raritan and Magothy formations has, in the European 428 SysteMATIC PALEONTOLOGY material, furnished abundant four-valved cones which induce Velenovsky and Krasser to advocate its reference to Widdringtonia. Widdringtonites subtilis Heer which is common in the later Cretaceous of the Coastal Plain has also furnished somewhat poorly preserved cones of this type in material collected by the writer in South Carolina, and well preserved attached cones in material from the Tuscaloosa formation in Alabama. There can be but little doubt of the actual genetic relationship be- tween these Mesozoic conifers and the existing species of Callitris, Wid- dringtoma, and Frenela which Kichler lumps into the single genus Callitris Vent. At the present time they constitute a restricted group confined to the Australian region on the one hand (Frenela) and to northern Africa (Hucallitris) and southern Africa and Madagascar (Widdringtonia) on the other. In former geological periods they were much more abundant as is partially shown by the accompanying sketch map, which, however, is designed to show only their reported range in the Mesozoic and does not include the quite numerous Cenozoic records. It will be seen that Frenelopsis is recorded in America from Greenland to Texas and Widdringtonites from Greenland to Alabama. Abroad both types occur abundantly in central and western Kurope. Like so many other types of plants which were widespread in Mesozoic times they became during the Tertiary more and more restricted in their range until today they are not found at all in the western hemisphere and are confined to the limited areas indicated on the accompanying sketch map. (Fig. 15.) Referring only to Cretaceous species of Widdringtonites we find four in the Neocomian, one in the Barremian, one in the Albian, three in the Cenomanian and one'in the Senonian. The corresponding occurrences of the allied species of Frenelopsis are discussed under that genus. WIDDRINGTONITES RAMOSUS (Fontaine) Berry Plate LXXIII, Figs. 1-6 Taxodium (Glyptostrobus) ramosum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 251, pl. cxxiii, figs. 2, 3; pl. cxxiv, fig. 2; pl. exxvii, fig. 1; pl. cxxxii, fig. 1; pl. clxvi, fig. 1. MaryLanp GEOLOGIOAL SuRVEY 429 Taxodium (Glyptostrobus) brookense Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 254, pl. exxii, fig. 1; pl. exxiv, figs. 3-9; pl. cxxxi, fig. 5; pl. clxv, figs. 1-8; pl. elxvi, figs. 4, 7; pl. elxvii, fig. 3. Taxodium (Glyptostrobus) brookense angustifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 256, pl. elxvii, fig. 1. Glyptostrobus brookensis Ward, 1895, 15th Ann. Rept. U. S. Geol. Surv., p. 359. Glyptostrobus brookense angustifolium Knowlton, 1898, Bull. U. S. Geol. Surv., No. 152, p. 112. Glyptostrobus brookensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 481, 489, 495, pl. cx, fig. 1 (non pp. 483, 486, 520 which are referred to Arthrotaxopsis expansa Font.). Glyptostrobus ramosus Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol. xlviii, 1906, pp. 281 (?), 489, 544. Glyptostrobus brookensis angustifolius Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 489, pl. cviii, fig. 4. Arthrotazxopsis expansa Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 547 (non balance of original citation). Widdringtonites ramosus Berry, 1911, Proc. U. 8. Natl. Mus., vol. xl, p. 302. Description.—*“ The principal stems seen are moderately stout and very rigid, the secondary ones mostly slender and rigid, the ultimate ones usually very long, slender, and unbranched, widespreading, often very delicate and thread-like, going off at an angle of about 45°, but from distortion due to pressure frequently appearing fastigiate and irregularly grouped; leaves on the oldest stems elongate-linear, acute, close appressed, on the younger stems all very narrowly oblong, or nar- towly elliptical, acute to obtuse, very closely appressed, not distinctly visible without the help of a lens in many cases, all spirally arranged; the facial leaves usually acute, the lateral ones usually more obtuse and sometimes slightly divergent at the tips and incurved; midnerves slender and thread-like.”—Fontaine, 1890. Since nowhere in the Potomac Group are cones or scales found which indicate the presence of Glyptostrobus it seems desirable to refer these species and variety of Prof. Fontaine’s to the genus Widdringtonites because of their extremely close resemblance to Widdringtonites Reichti (Ettings.) Heer, which is so widespread and characteristic a form in the Cepomanian of both the Old and New World. In fact it may be event- ually desirable to reduce this Patapsco species to the synonymy of the 430 SYSTEMATIC PALEONTOLOGY latter, to which it is at least very closely allied. The variety angusti- folium Fontaine is not distinguishable from the type and is based on specimens slightly more slender than the average, but readily matched in the material which that author refers to the type species. Glypto- strobus ramosus (Font.) Ward is clearly identical with the other forms of Fontaine’s which are included in this species and comes from the same outcrops with the exception of certain material from the Kootanie at Great Falls, Montana which Prof. Fontaine has identified as Glyptos- trobus ramosus but which is in all probability Glyptostrobus grelandi- cus Heer and not identical with the Potomac species, although detached twigs of the two may and do show considerable similarity. The material from the Fuson formation of eastern Wyoming which Fontaine referred to his Glyptostrobus brookensis, a synonym of Wid- dringtonites ramosus, is clearly identical with Sphenolepis Kurriana (Dunker) Schenk which occurs in the same beds with it and quite different from the species under discussion. Widdringtonites ramosus is a characteristic species of the Patapsco formation both in Maryland and Virginia and occurs in considerable abundance at numerous localities. It is undoubtedly the ancestor of Widdringtonites Reichii (Mttings.) Heer of the Raritan and Magothy formations. Stomata of the same general type as those described by the writer in Frenelopsis ramosissima (see supra), but confined to certain areas on the tiny crowded leaves, are described by Caspary for Widdringtonites oblongifolius Goeppert and Meng., a Tertiary relative of these Lower Cre- taceous forms.” Occurrence——Patapsco Formation. Ft. Foote and Overlook Inn Road, Stump Neck, near Wellhams, Vinegar Hill, Maryland; Mt. Vernon, Hell Hole, White House Bluff, near Brooke, 72-mile post, Virginia. Collection.—U. 8. National Museum. 1 Abhandl. k. Preuss. Geol. Landes., neue folge, Heft iv, 1907, p. 66: Atlas, pl. ix, see especially fig. 53c. MARYLAND GEOLOGICAL SURVEY 431 Subfamily TAXODIEAE Genus SPHENOLEPIS Schenk [Paleontographica, Band xix, 1871, p. 243] The generic name Sphenolepidium was proposed by Heer as a substi- tute for Sphenolepis Schenk (1871) as the latter had been previously used in the animal kingdom. In his treatment of these plants in Zittel’s Handbuch Schenk adopts Heer’s generic name which had meanwhile come into general use. As however, all modern nomenclatorial codes, both zoological and botanical, do not regard the use of a name in the one kingdom as prohibiting its use in the other we must return to Schenk’s original usage. Sphenolepis may be defined as follows: Branches and twigs alternate. Phyllotaxy spiral. Leaves decurrent, more or less imbricated, acute, more or less appressed, especially on the older branches. Cones small, oblong or spherical, borne on short lateral branches. Cone-scales per- sistent, leathery, somewhat divergent at maturity, in habit suggesting Sequoia. The number and position of the seeds is altogether uncertain. Although Solms-Laubach considers * that these forms cannot be pre- cisely located in any of the existing subfamilies of Conifers most authors refer them to the Taxodiee comparing them with the existing species of Sequoia and Arthrotazis, especially the latter, with which as regards the cones the leaf form and arrangement and the general habit there is the closest similarity, amounting almost to an actual demonstration ‘of relationship. The genus appears in beds of Rhetic age both in Europe and South America. In North America one species has been recorded from the Oregon Jurassic, and Saporta has described a species from the Upper Jurassic of Portugal. Species of this genus are widespread and char- acteristic of the Wealden and Lower Cretaceous and constitute a very abundant element in the flora of the Potomac Group, where they are represented by remains of both foliage and cones. As has been frequently pointed out the genus may be composite since the difficulty of separation 1Solms-Laubach, Fossil Botany, 1891, p. 71. 28 432 SyYsTEMATIC PALEONTOLOGY of fossilized fragments of different conifers with a similar vegeta- tive habit is almost unsurmountable and very similar twigs are often referred to Sequoia. SPHENOLEPIS Kurriana (Dunker) Schenk * Plate LX XIV, Figs. 2, 3 Thuites (Cupressites ?) Kurrianus Dunker, 1846, Mon. Norddeutsch. Weald.- bild., p. 20, pl. vii, fig. 8. Widdringtonites Kurrianus Endlicher, 1847, Synopsis, p. 272. Brachyphyllum Kurrianum Brongniart, 1849, Tableau, p. 107. Brachyphyllum Germari Brongniart, 1849, Tableau, p. 107. Widdringtonites Kurrianus Géppert, 1850, Foss. Conif., p. 176. Thuites Germari Unger, 1850, Gen. et Sp., p. 348.? Widdringtonites Kurrianus Unger, 1850, Ibid., p. 342. Widdringtonites Kurrianus Httings., 1851, Abb. k. k. geol. Reichs., Band i, Abth. iii, p. 25. Widdringtonites Haidingeri Ettingshausen, 1851, Ibid., p. 26, pl. ii, fig. 1. Araucarites Dunkeri Ettingshausen, 1851, Ibid. (pars), p. 27, pl. ii, figs. 2-10. Widdringtonites Kurrianus Hildebrand, 1861, Verbreit. Conif., 1861, p. 296. Widdringtonites Haidingeri Hildebrand, 1861, Ibid., p. 296. Widdringtonites Kurrianus Schimp., 1870, Pal. Végét., tome ii, p. 329. Sphenolepis Kurriana Schenk, 1871, Paleont., Band xix, p. 243, pl. xxxvii, figs. 5-8; pl. xxxvili, fig. 1 (non fig. 2 which is an Onychiopsis). Sphenolepis Kurriana Schimper, Pal. Végét., Atlas, 1874, pl. cx, fig. 26. Sphenolepidium Kurrianum Heer, 1881, Contrib. Fl. Foss. Port., p. 19, pl. xii, fig. 1b; pl. xiii, figs. 1b, 8b; pl. xviii, figs. 1-8. Sphenolepidium Kurrianum Schenk, 1884, in Zittel, Handbuch, p. 304, fig. 210. Sphenolepis Kurriana Hosius and v. d. Marck, 1885, Paleont., Band xxvi, p. 216, pl. xliv, fig. 209. Sphenolepidium Kurrianum Fontaine, 1890, Mon. U.S. Geol. Surv., vol. xv, 1889, p. 260, pl. cxxvi, figs. 1, 5, 6; pl. cxxviii, figs. 1, 7; pl. exxix, figs. 1, 4, 6, 8; pl. exxx, fig. 11; pl. cxxxi, fig. 4; pl. elxvii, fig. 2. *The following are included in the synonymy of this species by Seward (loc. cit.): Muscites imbricatus Roember, Verstein., 1839, p. 9, pl. xvii, fig. le (this is doubtful and would change the specific name if recognized) ; Araucarites hamatus Trautschold, Nouv. Mém. Soc, Nat. Moscou, tome xiii, 1870, p. 225, pl. xxi, fig. 3; and Thuites Choffati Heer, loc. cit., 1881, p. 11, pl. x, fig. 8. * Since it would involve a change in the specific name of this well-known species, Thuites Germari Dunker, Mon. Norddeutsch. Weald.-Bild., p. 19, 1846, is omitted from the synonymy as being of uncertain value. MaryLanp GEoLogicaL SuRVEY 433 Sphenolepidium parceramosum Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. Xv, 1889, p. 257, pl. exxix, fig. 7; pl. exxx, fig. 8; pl. exxxi, fig. 2. Arthrotaxopsis grandis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 240 (pars). Sphenolepidium virginicum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 259, pl. exxv, fig. 4; pl. clxvi, fig. 6. Arthrotaxopsis expansa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 241 (pars), pl. cxxxv, figs. 15, 18, 22. : Taxodium (Glyptostrobus) expansum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 252, pl. exxiii, fig. 1. Taxodium (Glyptostrobus) denticulatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 253, pl. cxxiv, fig. 1. / Taxodium (Glyptostrobus) fastigiatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 258, pl. exxv, figs. 1, 3. Sphenolepidium Kurrianum Saporta, 1894, Fl. Foss. Port., pp. 115, 139, pl. xxii, figs. 3-5; pl. xxvii, fig. 15. Sphenolepidium Kurrianum Seward, 1895, Wealden F1., pt. ii, p. 200, pl. xvii, figs. 7, 8; pl. xviii, fig. 1. Glyptostrobus fastigiatus Ward, 1895, 15th Ann. Rept. U. S. Geol. Surv., p. 380. Sphenolepidium Kurrianum Kerner, 1896, Jahrb. k. k. geol. Reichs., Band xlv, Heft i, p. 51, pl. iv, fig. 2. Sphenolepidium Kurrianum Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 681, pl. clxvi, figs. 12, 13. Sphenolepidium parceramosum Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 682, pl. clxiii, fig. 11b; pl. clxviii, figs. 1-3. Glyptostrobus brookensis Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 682, pl. clxv, fig. 4; pl. clxviii, fig. 4. Sphenolepidium Kurrianum Fontaine, 1906, in Ward, Mon. U. 8S. Geol. Surv., vol. xlviii, 1905, pp. 484, 489, 519, 538, 543. Sphenolepidium parceramosum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 484, 538, 548. Sphenolepidium virginicum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 481, 484, 517. Glyptostrobus expansus Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol, xlviii, 1905, p. 548. Sphenolepis Kurriana Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 291. Description.—* Thuites ramulis erectis irregulariter pinnatis, compres- siusculis utrimque subcarinatis, foliolis crassiusculis imbricatis irregu- lariter dispositis elongatis subflexuosis apice acutis dorso carinatis sub- distantibus.”—-Dunker, 1846. In habit the twigs are alternate, branching copiously, more or less crowded, with a tendency toward a fastigiate arrangement in numerous 434 SysTEMATIC PALEONTOLOGY specimens. Leaves thick, keeled dorsally, ovate in outline, often broadly so, acuminate, often slightly recurved, rather crowded and more or less appressed but larger than and much more divergent than those of the genera Arthrotaropsis or the Lower Cretaceous species of Widdring- tonites. Phyllotaxy spiral. Cones small, globose or oblate spheroidal; scales few in number, short and thick, truncate distally, becoming more or less divergent with age. This species is very common at a large number of Lower Cretaceous horizons in both Europe and America and it has also been recorded from the Cenomanian in Portugal, Saxony, and Austria (Lesina). It is present in the Neocomian of Portugal and Westphalia and doubtfully in beds of this age in Russia. It is present in the Wealden of England -and Germany, the latter being the type locality. It is also recorded from the Barremian of Portugal and is probably present in the Kome beds of Greenland. In this country it is recorded from the Kootanie of Montana and the Fuson formation of the Black Hills. It is a very abundant form in the Potomac Group and occurs at numerous localities ranging in age from the oldest or Patuxent beds to the youngest or Patapsco beds, a range similar to but somewhat less in time than that ascribed to it in Portugal, where Saporta recognizes it from the Neoco- mian to the Cenomanian. Some of the numerous specimens from the Kome beds of Greenland, which Heer described first as Widdringtonites gracilis* and afterwards as Cyparissidium gracile,’ are probably identical with Sphenolepis Kurriana (Dunker) Schenk although the cones ascribed to the former differ from those of the latter. Heer notes the resemblance between the remains of foliage of Cyparissidium, Widdringtonites, Glyptostrobus, Arthrotagis, and Sequoia. Araucarites hamatus Trautschold which Seward (Joc. cit.) doubtfully includes in the synonymy is here excluded. There is some suggestion of Sphenolepis in Trautschold’s figures but not enough for certainty. These figures are, however, almost identical with the coniferous twigs *Heer, Fl. Foss. Arct., Band i, 1868, p. 83, pl. xliii, figs. le, f, g, 3c. * Heer, Ibid., Band iii, Abth. ii, 1874, p. 74, pl. xvii, figs. 5b, c; pl. xix; pl. xx, fig. le; pl. xxi, figs. 9b, 10d. MaryLanp GroLogicaL SuRVEY 435 from Glen Rose, Texas, which Fontaine describes as Sequoia pagiophyl- loides sp. nov. The species may be a composite one, its wide geographical and geo- logical range offers some basis for such a suspicion, but the materials available for study do not furnish reliable data for its segregation. Occurrence.—PATUXENT ForMaATIoN. New Reservoir, Ivy City, Dis- trict of Columbia; Fredericksburg, Potomac Run, Trents Reach, Dutch Gap, Telegraph Station (Lorton), Cockpit Point, Kankeys, Virginia. ARUNDEL Formation. Bay View, Arlington, Maryland. Patapsco Formation. Federal Hill (Baltimore), Vinegar Hill, Maryland; near Brooke, 72-mile post, Mt. Vernon, Hell Hole, Virginia. Collections——U. 8. National Museum, Johns Hopkins University. SPHENOLEPIS STERNBERGIANA (Dunker) Schenk Plate LXXV, Figs. 1, 2 Muscites Sterndergianus Dunker, 1846, Mon. Norddeutsch. Weald.-Bild., p. 20, pl. vii, fig. 10. Juniperites Sternbergianus Brongniart, 1849, Tableau, p. 108. Muscites Sternbergianus Unger, 1850, Gen. et Sp., p. 42. Araucarites Dunkeri Ettingshausen, 1851, Abh. k. k. geol. Reichs., Band i, Abth. iii, p. 27, pl. ii, figs. 2, 3, 7,8 (pars). . Araucarites curvifolius Ettingshausen, 1851, Ibid., p. 28, pl. ii, figs. 11, 18, 14, 17-21. Araucarites Dunkeri Hildebrand, 1861, Verbreit. Conif., p. 276. Widdringtonites Dunkeri Schimper, 1870, Pal. Végét., tome ii, p. 329. Widdringtonites curvifolius Schimper, 1870, Ibid. Sphenolepis Sternbergiana Schenk, 1871, Paleont., Band xix, p. 243, pl. xxxvii, figs. 3, 4; pl. xxxviii, figs. 3-13. Sequoia gracilis Heer, 1873, Fl. Foss. Arct., Bd. iii, Ab. ii, p. 80, pl. xviii, fig. 1c; pl. xxii, figs. 1-10. Sphenolepis Sternbergiana Schimper, 1874, Pal. Végét., tome iii, p. 575, Atlas, pl. cx, fig. 27. Sphenolepidium Sternbdergianum. Heer, 1881, Contrib. Fl. Foss. Port., p. 19, pl. xiii, figs. 1a, 2-8; pl. xiv. Sphenolepis Sternbergiana Hosius and v. d. Marck, 1885, Paleont., Band xxvi, p. 215, pl. xliv, figs. 206-208. Sphenolepidium Sternbergianwm Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 261, pl. cxxi, figs. 8, 10, 11; pl.-cxxx, fig. 9. Sphenolepidium Sternbergianum densifolium Fontaine, 1890, Mon. U. 8. Geol. Surv., vo}, xv, 1889, p. 261, pl. exviii, fig. 7; pl. exxi, figs. 5, 7, 9; pl. exxv, fig. 2; pl. cxxix, fig. 3; pl. exxx, fig. 1; pl. exxxi, figs. 1, 3; pL exxxii, fig. 4. 436 SYSTEMATIC PALEONTOLOGY Sequoia gracilis Fontaine, 1890, loc. cit, (non 1899), p. 247, pl. exxvi, figs. 3, 4. : Sphenolepidium Sternbergianum densifolium Fontaine, 1893, Proc. U. S. Natl. Mus., vol. xvi, p. 268, pl. xxxvi, fig. 10. Sphenolepidium Sternbergianum Saporta, 1894, Fl. Foss. Port., pp. 114, 189, 193, pl. xxii, figs. 1, 2; pl. xxvii, fig. 14; pl. xxxiii, fig. 13. Sphenolepidium Sternbergianum Seward, 1895, Wealden F1., pt. ii, p. 205, pl. xvi, figs. 4-6. Sphenolepidium Sternbergianum Ward, 1895, 15th Ann. Rept. U. S. Geol. Surv., p. 359, pl. iii, fig. 1. Sphenolepidium Sternbergianum Fontaine, 1906, in Ward, Mon. U. 8. Geol. Surv., vol. xlviii, 1905, p. 264, pl. lxix, fig. 7. Sphenolepidium Sternvergianum densifolium Fontaine, 1906, in Ward, loc. cit., vol. xlviii, 1905, pp. 480, 481, 484, 486, 491, 507, 511, 515, 524, 528, 544, 546, 555, 578, pl. cix, figs. 8, 9; pl. cxii, figs. 1, 10 (non fig. 11 which is referred to Arthrotaxopsis expansa Font.); pl. exv, fig. 1. Sequoia gracilis Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, p. 126. Sequoia gracilis ? Hollick, 1907, Mon. U. S. Geol. Surv., vol. 1, p. 43, pl. iii, fig. 14. Sphenolepidium Sternbergianum Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. xix, p. 386. Sphenolepis Sternbergiana Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 293. Description Muscites caule virgato subflexuoso, foliis bifariis imbricatis patentibus ovatolanceolatis subfalcatis’”’"—Dunker, 1846. The branches are somewhat more remote than in Sphenolepis Kurriana, with relatively shorter twigs. Leaves ovate, decurrent, keeled, with a broad base and acuminate apex, often divergent and falcate, in other specimens appressed. In general the leaves are much more crowded and divergent than in the preceding species. Cones not collected in connection with the American material except in the case of some poorly preserved specimens from Mt. Vernon figured by Ward (1895 loc. cit.) which may be immature, although they suggest the preceding species rather than this one. Cones are described by Schenk from the German Wealden and are also figured by Seward from the English Wealden. The cones are small, oblate-spheroidal in shape, with few, stout, truncated scales which become more or less divergent with maturity. Ward (loc. cit.) reports specimens of the foliage of this species with attached staminate catkins similar to those described by Fontaine as “Male aments” from various Virginia localities, where they were not attached to recognizable twigs. MarYLAND GEOLOGICAL SURVEY 437 This species was described by Dunker in 1846 as a species of Muscites, Brongniart in 1849 substituting Juniperites as a more appropriate generic name, one subsequently changed to Araucarites by Ettingshausen. Schimper referred this species to Widdringtonites, but since 1871 it has been rather consistently referred to as Sphenolepis, or Sphenolepidium Sternbergianum ; although the difficulty of dealing satisfactorily with various detached coniferous twigs of similar habit is no small one, not only from their’ similar appearance in various unallied species but also because of their resistance of decay and retention of their leaves when reduced to fragments, so that they are often the most abundant remains in coarse sediments. Sphenolepis Sternbergiana has an equally wide range, both geographic and geologic, as has the preceding species. It is common in the Wealden of England and Germany and is recorded by Saporta from the Neoco- mian, Barremian, and Albian of Portugal, a range similar to that which it shows in the Maryland-Virginia area. It is probably represented in the Kome beds of Greenland by Sequoia gracilis Heer while the latter author’s Glyptostrobus groenlandicus* and Sequoia fastigiata from these beds also suggest this species. It is recorded from the Glen Rose (Trinity) beds of Texas and from the Horsetown beds of the Pacific Coast. The form from the Upper Cretaceous of Marthas Vineyard which Hollick has identified as Sequoia gracilis Heer is also similar enough to be suggestive. The present species is very abundant in the Potomac Group ranging from the bottom to the top. The specimens of Sphenolepis Sternbergiana from the Wealden of Ecclesbourne in possession of the writer, are much stouter than the American conifer usually identified as this species and resemble rather closely what in America goes by the name of Sequoia ambigua Heer, a resemblance already commented on by Seward (Wealden FI. pt. ii, p. 206, 1895); since, however, the preservation is poor, too much impor- tance cannot be attached to a resemblance which may be purely super- ficial, although in the opinion of the writer it seems probable that some 1Heer, Fl. Foss. Arct., Band iii, Abth. ii, p. 76, pl. xvii, fig. 9; pl. xx, figs. 9, 10. 438 SYSTEMATIC PALEONTOLOGY at least of the Wealden twigs identified as Sphenolepis Sternbergiana may really be those of Sequoia ambigua, which in this country we have no difficulty in distinguishing from Sphenolems. Occurrence.—PatuxENt Formation. Fredericksburg, Telegraph Station (Lorton), Potomac Run, Alum Rock, Cockpit Point, Wood- bridge, Virginia. ArunpEL Formation. Langdon, District of Colum- bia; Hanover, Tip Top, Soper Hall, Maryland. Parapsco FormarTion. Grays Hill, Ft. Foote, Stump Neck, Maryland; Mt. Vernon, White House Bluff, Hell Hole, Chinkapin Hollow, 72-mile post, Dumfries Landing, near Widewater, Aquia Creek, Virginia. Collections—U. 8. National Museum, Johns Hopkins University. Genus ARTHROTAXOPSIS Fontaine (Mon. U. S. Geol. Survey, vol. xv, 1890, p. 239] The genus Arthrotaxopsis named from its resemblance to the modern genus Arthrotaxis Don of the subfamily Taxodieew which has three species confined to Tasmania, is characterized in the following terms by its describer : “Trees or shrubs, copiously branching, with principal stems or branches proportionally strong, cylindrical, rigid, sending off thickly placed, long, slender, cord-like, ultimate twigs, all in the same plane and spreading widely; the ultimate twigs leave the penultimate ones under a very acute angle and show a tendency to a fastigiate grouping; cones mostly broadly oblong, rarely globular, obtuse and rounded at base and apex, average dimensions 10 mm. by 14 mm. attached singly on the summit of short lateral branches and placed on the lower portions of the leafy stems and branches, the twig with its cone repre- senting the branching leafy twigs which occur higher up; scales of the cones woody, thick, wedge-shaped in the basal portions, expanded at the ‘free ends, and probably shield-shaped, numerous, spirally placed, attached at a large angle, the middle ones being nearly or quite at a right angle with the axis, close appressed, opening with age; seed under each scale one, elliptical in shape, smooth and bony in texture, average dimensions 1 mm. by 2.5 mm; leafy branches ending abruptly in an ultimate twig MARYLAND GEOLOGICAL SURVEY 439 similar to those sent off pinnately and alternately lower down; leaves very thin and scale-like, elliptical, rhombic, or oblong, with varying age changing their shape, the rhombic forms representing the oldest and most crowded leaves, slightly keeled on the back, spirally arranged.” The only qualification that it is necessary to make in the foregoing description is that referring to a single, smooth, bony seed under each cone-scale. The present writer has been entirely unable to verify this feature in any of the material some of which, however, suggests such a seed habit. The cones are of small size and comparable to the cones usually referred to Sequoia, 1. ¢., with wedge-shaped peltate scales. The material is all poorly preserved and the leafy twigs have evidently suf- fered greatly from decay before fossilization. The genus may be distinguished from Arthrotaxites Unger, Hchinos- trobus Schimper,’ and Cyparissidiwm Heer,’ all of which have very similar leafy twigs, by the characters of the cones, which are quite different. The first two are Jurassic while the last extends from the Rheetic to the Upper Cretaceous. As a rule the twigs of Arthrotaxopsis are more elon- gated and slender than those of these other genera, indicating beyond doubt a pendulous habit. As originally described Arthrotaxopsis contained four species. Two of these prove to be identical with the species described below while the third was composite and included specimens of both Sphenolepis Kur- riana (Dunker) Schenk and Sequoia ambigua Heer. ARTHROTAXOPSIS EXPANSA Fontaine Plate LXXIV, Fig. 1 Arthrotaxopsis expansa Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 241, pl. exiii, figs. 5, 6; pl. exv, fig. 2; pl. exvii, fig. 6 (non pl. exxxv, figs. 15, 18, 22 which are referred to Sphenolepis Kurriana (Dunker) Schenk). Taxodium expansum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, "pp, 252, pl. exxiii, fig. 1. 1Unger, Bot. Zeit., 1849, Nr. 19. 2 Schimper, Pal. Végét., tome ii, 1870, p. 330. * Heer, FI. Foss. Arct., Bd. iii, Abth. ii, 1874, p. 74. 440 SYSTEMATIC PALEONTOLOGY Arthrotaxopsis expansa Fontaine, .1906, in Ward, Mon. U. 8S. Geol. Surv., vol. xlviii, 1905, pp. 504, 520, 546, 571 (non pp. 533, 535, 538, 555, 573, pl. cix, figs. 12, 13 which are referred to Sequoia ambigua Heer, and p. 547 which is referred to Widdringtonites ramosus (Font.) Berry). Glyptostrobus expansus Ward, 1906, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 543. Sphenolepidium Sternbergianum densifolium Fontaine, 1906, in Ward, Mon. U.S. Geol. Surv., vol. xlviii, 1905, p. 524 (pars), pl. exii, fig. 11 (non figs. 1, 10). Glyptostrobus brookensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 483, 486, 520 (non other citations). Arthrotaxopsis expansa Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 297. Description.—Branches and twigs elongated and extremely slender, widely spreading and sparingly branched, showing a tendency as pre- served to be in a single plane although it cannot be determined to what extent this reflects the original habit of the plant. Leaves spirally arranged, thick, keeled, acute, showing a tendency to become obtuse and less appressed, especially on the older twigs. As here delimited this species is confined to the older Potomac although it is very similar to those forms from the Patapsco formation which are described as Widdringtonites ramosus (Fontaine) Berry, the latter being more copiously branched, less spreading, and with more acute leaves which frequently become more or less elongated. These differences may or may not be of specific value. As preserved the two plants differ decidedly in aspect but this is due largely to the spreading habit of the present species, and is approached in some of the coniferous twigs from Mt. Vernon which are referred to Widdringtonites. The relation to Arthrotaris implied by the name is not certain and the present species is retained in the genus to which it was referred by Professor Fontaine, more from a desire to avoid changes which do not appear to be justified by the meager evidence at hand than from any conviction of relationship. For the same reason it was not trans- ferred to Widdringtonites although it seemed desirable in the case of Widdringtonites ramosus to make such a change and bring the latter in association with the Upper Cretaceous species of that genus with which there is such a close agreement. MARYLAND GEOLOGICAL SURVEY 441 Following Seward’s suggestion,’ the cones that Fontaine referred to this species are considered to belong to Sphenolepis Kurriana (Dunker) Schenk, as are also some of the leafy twigs which Fontaine identified as Arthrotaxopsis, and a number of the recorded occurrences of the latter have also been found to belong to Sequoia ambigua Heer. The present is another of the several species which may be compared with the foliage from the Lower Cretaceous of Greenland which Professor Heer referred to Cyparissidium. Occurrence.—PaTuUxENT Formation. Roadside near Potomac Run, Telegraph Station (Lorton), Trents Reach, Cockpit Point, Dutch Gap, Virginia; Springfield (?), Maryland. ArunpErL Formation. Langdon (common), District of Columbia; Tip Top (?), Maryland. Collection.—U. 8. National Museum. ARTHROTAXOPSIS GRANDIS Fontaine Plate LXXVI, Plate LXXVII, Fig. 6 Arthrotaxopsis grandis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 240 (pars), pl. exiv, figs. 1-3; pl. cxvi, figs. 1-4; pl. exxxv, fig. 10. Arthrotaxopsis tenuicaulis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 241, pl. exiv, figs. 4, 5; pl. exv, fig. 4; pl. exvi, fig. 6; pl. exvii, fig. 2. Arthrotaxopsis pachyphylla Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 242, pl. cxv, figs. 1, 3; pl. exvii, figs. 1, 3-5. Arthrotaxopsis tenuicaulis Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 674, pl. clxiv. Arthrotaxopsis grandis Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 546. Arthrotaxopsis tenuicaulis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol, xlviii, 1905, pp. 516, 520, 538, 546, 571. Arthrotaxopsis grandis Berry, 1911, Proc. U. 8. Natl. Mus., vol. xl, p. 296. Description.—Leafy twigs elongate and slender, especially the distal ones which are extremely attenuated and unbranched or sometimes dichotomously branched. Main branches alternate, much branched, apparently in a single plane. Distal twigs crowded, somewhat fastig- iate. Leaves usually thin, closely appressed, elliptical to rhombic in shape, slightly keeled, acute. Phyllotaxy spiral. Cones small, ovoid, i 1 Seward, Wealden FI1., pt. ii, 1895, p. 201. 442 SyYsTEMATIO PALEONTOLOGY 5 mm. to 10 mm. in diameter and 1 cm. to 1.5 cm. in length, made up of a small number of relatively thick, wedge-shaped, peltate scales, be- coming somewhat spreading with age. This species may be distinguished from Sphenolepis Kurriana (Dun- ker) Schenk with which it was confused by Professor Fontaine by the method of branching and by its longer and more slender twigs as well as by the usually more spreading leaves of Sphenolepis. The material which constituted the species tenuicaulis and pachyphylla of Fontaine is not separable from that of the type. It comes from the same beds and differs merely in the condition of preservation and relative positions of the twigs upon the branch. Under Arthrotaxopsis grandis was also included originally certain material from near Brooke, Virginia, which is referable to Sphenolepis. Both the foliage and the cones are common in the Patuxent and Arundel formations and, so far as known, they do not extend above the top of the latter. Very ambiguous material from the Hay Creek beds of the Fuson formation in Wyoming are referred to this species by Fontaine. Occurrence——Patuxent Formation. Springfield, Fort Worthing- ton (Baltimore), Maryland; Dutch Gap and Fredericksburg, Virginia; 16th St., District of Columbia. ArunpsL Formation. Tip Top, Arlington, Bay View (cones and foliage common), Maryland; Langdon, District of Columbia. Collections —U. 8. National Museum, Johns Hopkins University. Genus SEQUOIA Endlicher [Synop. Conif., 1847, p. 197] “Flores in diversis ramulis monoici. Staminig. Amenta axillaria globosa, subspicata, perulata. Stamina plurima, axi inserta; filamenta brevissime filiformia, in connective squamulam late ovatum, verticalem producta, anther loculis duobus, connectivi basi continuis, discretis, parallelis, postice longitudinaliter bivalvibus. Seminif. Amenta. ... . Strobilus subglobosus, squamis coriaceo lignosis, suborbicularibus, ungue brevi excentrico peltatis, lamina rugosa margine involuta, medio breviter - mucronata, persistentibus. Semina subquavis squama 5-, infra ejusdem MaryYLanD GEOLOGICAL SURVEY 443 marginem superiorem libere pendula, tuberculis minutishilo orbiculari inserta, elliptica, compressa, integumento subcrustaceo utrinkue in alam membranaceum rigidam, latiusculam, basi ad hilum emarginatam, apice versus micropylen deorsum spectantem sensim angustatam pro- ducto, Albumen carnosum. “ Abores Californice, gigantee. Rami alterni, teretes, foliis abbre- viatis anguste lanceolatis longe adnato decurrentibus vestiti; ramulorum foliis linearibus, alternis distiche lineari-subfalcatis, obtusiusculis v. acutis, rigide coriaceis, persistentibus, supra lucidis, sulco longitudinali exaratis, subtus nervo valido, et utrinque juxta nervum stomatum fasciis albidis notatis. Semme terminales perulate, perulis ad innovationes persistentibus. Amenta staminigera in ramulis axillaribus brevissimis solitaria, spe spicnm foliatam referentia. Strobili in ramulis brevibus, perulis imbricatis tectis ad innovationes solitarii, nucis Avellane magni- tudine, squamis in rhachi persistentibus.”—Endlicher, 1847. What appears to be the earliest authentic record of a Sequoia is fur- nished by the cones found in the Portlandian of France." Ranging through the succeeding Lower Cretaceous deposits about a dozen species are known. The localities include Maryland, Virginia, California, Montana, Wyoming, and Texas; and outside the United States, British Columbia, Greenland, Mexico, Spitzbergen, Portugal, Belgium, Germany, Switzerland, England, and Russia. Wood of the Sequoia type of struc- ture is also known from the Lower Cretaceous of this country and Europe. In the Upper Cretaceous species of Sequoia become still more abundant and they apparently extend their range and specific differen- tiation throughout the greater portion of the succeeding Tertiary period ; some of the forms, represented by foliage, cones and wood, being almost identical with the modern red wood Sequoia sempervirens (Lamb.) Endl., while others appear to be ancestral to the modern big tree of Cali- fornia Sequoia washingtoniana (Winsl.) Sudworth. The climatic changes of the Pleistocene seem to have inaugurated the extinction of this type which had previously become restricted in America by the 1Wliche and Zeiller, Bull. Soc. géol. France (iv) tome iv, 1904, p. 798, pl. xix, figs. 4, 5. 444 SysteMAtTIc PALEONTOLOGY extensive development of the plains type of country which was too arid for their continued existence. Both the sempervirens and the washing- toniana type are present in the Pliocene of Europe at a large number of localities as well as three or four additional species represented by twigs, cones, seeds, and wood. In the present flora the redwood is common in the coast range from Oregon southward to Monterey County, California, while the big tree is confined to the west slopes of the Sierras from southern Placer County to Tulare County, California. Sequoia REICHENBACHI (Geinitz) Heer * Plate LXXVII, Fig. 7 Araucarites Reichenbachi Geinitz, 1842, Charakteristik d. Schichten u. Petrefacten sachs.-béhm. Kreide, Heft iii, p. 98, pl. xxiv, fig. 4. Cryptomeria primeva Corda, 1846, in Reuss, Versteinerungen béhm. Krei- def., Abth. ii, p. 89, pl. xlviii, figs. 1-11. Pinus exogyra Corda, 1846, in Reuss, Ibid., p. 91, pl. xlviii, figs. 16-18. Geinitzia cretacea Endlicher, 1847, Synop. Conif., p. 281. Pinites exogyrus Endlicher, 1847, Ibid., p. 284. Araucaria Reichenbachi Debey, 1849, Entwurf. z. e. Geogn.-Geogenst. Darst. d. Gegend v. Aachen (Nachtraége), p. 63. Cryptomerites primevus Brongniart, 1849, Tableau, p. 74. Geinitzia cretacea Unger, 1850, Gen. et Sp. Plant, Foss., p. 353. Piceites exogyrus G6ppert, 1850, Mon. Foss. Conif., p. 208. Cycadopsis cryptomerioides Miquel, 1853, Verh. Geol. Kaart. v. Nederl. Deel i, p. 42 (10), pl. iii. Araucarites adpressus v. d. Marck, 1863, Paleont., Band xi, p. 80, pl. xiii, figs. 10, 11. Cunninghamites Sternbergit HEttingshausen,? 1867 (nec syn.), Sitzb. k. Akad. Wiss. Wien, Bd. liv, Abth. i, p. 246, pl. 1, figs. 4-6. Sequoia Reichenbachi Heer, 1868, Fl. Foss. Arct., Band i, p. 83, pl. xliii, figs. 1d, 2b, 5a. Sequoia Reichenbachi Heer, 1869, Kreidefl. v. Quedlinburg, p. 9, pl. i, fig. 2 (Neue Denks. schweiz. Gesell. Naturw., Bd. xxiv). Sequoia Reichenbachi Heer, 1872, Fl. v. Moletein in M&hren, p. 7, pl. i, figs. 1-9 (Neue Denks. schweiz. Gesell. Naturw., Bd. xxiii, Mém. ii). +The following three citations, involving a change in the specific name of this well-known form are here omitted as being too uncertain: Conites familiaris Sternb., Bergeria minuta Presl, and Sedites ? Rabenhorstii Gein. *Included doubtfully by Heer and positively by Ward (very questionable). MARYLAND GEOLOGICAL SURVEY 445 Sequoia Reichenbachi Lesquereux, 1874, Cret. Fl., p. 51, pl. i, figs. 10, 10a, 10b. Sequoia Reichenbachi Heer, 1874, Fl. Foss. Arct., Bd. iii, Ab. ii, pp. 77, 101, 126, pl. xii, figs. 7c, d; pl. xx, figs. 1-8; pl. xxviii, fig. 2; pl. xxxiv, fig. 1; pl. xxxvi, figs. 1-8; pl. xxxvii, figs. 1, 2. Sequoia Reichenbachi Schenk, 1875, Paleont., Band xxiii, p. 168, pl. xxix, figs. 6, 7. Abietites dubius Lesquereux, 1878, Tert. Fl., p. 81, pl. vi, figs. 20, 21, 21a. Sequoia Reichenbachi Hosius and v. d. Marck, 1880, Paleont., Band xxvi, pp. 132, 179, pl. xxxvii, figs. 145, 146. Sequoia Reichenbachi Heer, 1882, Fl. Foss. Arct., Bd. vi, Abth. ii, p. 52, pl. xxviii, fig. 7. Sequoia Reichenbachi Dawson, 1882, Trans. Roy. Soc. Can., p. 21. Sequoia Reichenbachi Velenovsky, 1885, Gymn. bohm. Kreidef., p. 19, pl. viii, figs. 8, 9; pl. ix, fig. 5, 5a, 6a, 7a, 10a, 12, 12a, 13, 14. Sequoia ? sp., Fontaine, 1890, Mon. U. 8. Geol. Surv., vol. xv, 1889, p. 248, pl. exvi, fig. 7; pl. exxxii, figs. 2, 5, 6. Sequoia sp., Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 248, pl. exxxii, fig. 10. Sequoia Reichenbachi Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 243, pl. exvili, figs. 1, 4; pl. exix, figs. 1-5; pl. cxx, figs. 7, 8; pl. exxii, fig. 2; pl. clxvii, figs. 5. Sequoia Reichenbachi longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol, xv, 1889, p. 244, pl. exvii, fig. 8. Sequoia densifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 246, pl. cxxi, fig. 4. Sequoia Couttsie Hollick, 1892, Trans. N. Y. Acad. Sci., vol. xii, p. 30, pl. i, fig. 5 (non Heer). Sequoia Reichenbachi Hollick, 1892, Trans. N. Y. Acad. Sci., vol. xii, p. 30, pl. i, fig. 18. Sequoia Reichenbachi Lesquereux, 1892, Mon. U. S. Geol. Surv., vol. xvii, p. 35, pl. ii, fig. 4. Sequoia Reichenbachi Nathorst, 1893, in Felix and Lenk, Beitr. Geol. u. Pal. Mex., ii Theil, i Heft, p. 52, figs. 4, 5. Sequoia Reichenbachi Smith, 1894, Geol. Coastal Plain in Ala., p. 348. Sequoia Reichenbachi Newberry, 1896, Mon. U. S. Geol. Survey, vol. xxvi, 1895, p. 49, pl. ix, fig. 19. ; Sequoia Reichenbachi Krasser, 1896, Kreidefl. v. Kunstadt in Mahren, Paleont. Oest. Ung. u. d. Orients, Bd. x, p. 124. Sequoia Reichenbachi Fontaine, 1899, in Ward, 19th Ann, Rept. U. S. Geol. Surv., pt. ii, p. 674, pl. clxv, figs. 1, 2; pl. clxvi, fig. 1. Sequoia Reichenbachi Knowlton, 1899, Mon. U. S. Geol. Survey, vol. xxxii, p. 657. Sequoia Reichenbachi Ward, 1899, 19th Ann. Rept. U. S. Geol. Survey, table facing p. 712. Sequoia Reichenbachi Berry, 1903, Bull. N. Y. Bot. Gard., vol. iii, p. 59, pl. xlviii, figs. 15-18, 20. 446 SYSTEMATIC PALEONTOLOGY Sequoia Reichenbachi Berry, 1904, Bull. Torrey Club, vol. xxxi, p. 69, pl. iv, fig. 8. Sequoia Reichenbachi Knowlton, 1905, in Stanton and Martin, Bull. Geol. Soc. Amer., vol. xvi, p. 408. Sequoia Reichenbachi Berry, 1905, Bull. Torrey Club, vol. xxxii, p. 44, pl. i, fig. 3. Sequoia Reichendachi Berry, 1906, Ibid., vol. xxxiii, 1906, p. 165. Sequoia Reichenbachi Berry, 1906, Rept. State Geol. (N. J.), for 1905, p. 139. Sequoia Reichenbachi Hollick, 1906, Mon. U. S. Geol. Survey, vol. 1, p. 42, pl. ii, fig. 40; pl. iii, figs. 4, 5. Sequoia Reichenbachi Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, pp. 177, 263, 281, 544, pl. xlv, figs. 7, 8; pl. lxix, figs. 4, 5. Sequoia ? inferna Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol. xviii, 1905, p. 507. ‘ Sequoia Reichenbachi Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, p. 126, pl. xii, figs. 7, 8. Sequoia Reichenbachi Berry, 1910, Bull. Torrey Club, vol. xxxvii, p. 20. Sequoia Reichenbachi Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 308. Description—*“ 8. ramis elongatis, foliis decurrentibus, patentibus, falcato-incurvis, rigidis, acuminatis.”—Heer, 1869. This is one of the most wide-ranging fossil plants, both geologically and geographically, that is known, and it seems very probable that it is of a composite character, the well-known difficulty of distinguishing between coniferous twigs of this character prohibiting any satisfactory segregation. Described originally as a species of Araucarites certain of these remains from the Staten Island Cretaceous have shown by their vascular structure that they are related to the Araucariex, while on the other hand a large number of exactly similar remains of leaf-bearing twigs bore cones which are unquestionably those of a Sequoia. Twigs of this sort are abundant throughout the Potomac Group occurring also in the Fuson formation of the Black Hills, the Kootanie of Montana, the Shasta of California, the Kome beds of Greenland, and the Neoco- mian of Central Mexico. Abroad they have been reported from the Upper Jurassic (?) of Portugal, the Neocomian of Belgium, the Barremian of Silesia, and the Albian of Switzerland. Similar remains have also been described from a large number of horizons in the Upper Cretaceous, both in this country and abroad. MARYLAND GEOLOGICAL SURVEY 447 The slight variations from specimen to specimen and the varying conditions of preservation in the twigs of this species throughout the Potomac, together with the detached and more or less macerated cones furnished the basis for six species and varieties of Fontaine and Ward, but these are obviously not specifically distinct from one another. Occurrence—Patuxent Formation. Fredericksburg, Telegraph Station (Lorton), Dutch Gap, Virginia; Springfield, Maryland. Arun- DEL Formation. Reynolds Ore Pit, Maryland. Parapsco ForMaArTIoN. Near Brooke, Virginia. Collection.—U. S. Natiortal Museum. SEQUOIA RIGIDA Heer Plate LXXVIII, Fig. 8 Sequoia rigida Heer, 1873, Fl. Foss. Arct., Band iii, Abth. ii, pp. 80, 91, 102, 128, pl. xxii, figs. 5g, lla; pl. xxv, fig. 6; pl. xxvii, figs. 8-14; pl. xxxviii, figs. 9a, 10. Sequoia rigida Schenk, 1875, Paleont., Band xxiii, p. 168, pl. xxix, figs. 8, 9. Sequoia rigida Heer, 1882, Fl. Foss. Arct., Band vi, Abth. ii, p. 52, pl. vii, figs. 10-12; pl. viii, fig. 7; pl. xxi, fig. le; pl. xxiv, fig. 3b. Sequoia rigida Heer, 1883, Fl. Foss. Arct., Band vii, p. 13, pl. liii, figs. 5-7. Sequoia subulata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 245, pl. exvii, fig. 7; pl. exviii, figs. 5, 6 (non Heer). Sequoia rigida Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 246, pl. exviii, fig. 3; pl. cxxi, fig. 2; pl. exxvi, fig. 2; pl. cxxx, fig. 3. Sequoia rigida Knowlton, 1905, in Stanton and Martin, Bull. Geol. Soc. Amer, vol. xvi, p. 408. Sequoia rigida Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 219. Sequoia subulata Fontaine, 1906, in Ward, Ibid., pp. 486, 571. Sequoia rigida Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 309. Description.— 8. foliis coriaceis, rigidis, linearibus, apice acuminatis, patentibus, rectis, uninerviis, transversim subtilissime regulosis, basi non angustatis, adnato-longe decurrentibus.”—Heer, 1873, This species was described by Heer from the Kome beds of Greenland although he subsequently pointed out that it was more abundant in the Atane beds. He compared it with Sequoia Woodwardii (Carr.) Schimp., 29 448 SysTEMATIC PaLEONTOLOGY of the Upper Greensand of England and with Sequoia pectinata Heer of the Senonian of Germany. It is also recorded from the Gosau beds of Europe and from the Upper Cretaceous of Alaska as well as from the Potomac of Virginia, the Kootanie of Montana, and the Shasta of California. The specific identity of these Upper and Lower Cretaceous forms may well be doubted but no clear line of demarcation can be drawn between them at the present time. It is quite possible that the Potomac forms are merely variants of the abundant Sequoia Reichen- bacht since they fail to show the transverse rugosity (a feature of the preservation merely) described by Heer, and also appear to be some- what less decurrent and at times less finely pointed than the type material. A variety described by Saporta from the Albian of Portugal as var. lusitanica* is scarcely to be distinguished from the Potomac specimens. The Potomac specimens which Professor Fontaine identified as Sequoia subulata Heer are here referred to Sequoia rigida Heer with which they are obviously identical, in fact it seems probable that the type material of Sequoia subwlata cannot be distinguished from this species. There are differences in some of the specimens which Heer has identified with his Sequoia subulata, so that it seems best not to unite the two species at the present time. Occurrence.—PatTUxENT Formation. Near Potomac Run, near Tele- ‘graph Station (Lorton), Virginia; Springfield, Prince George’s County, Maryland. Collection.—U. S. National Museum. SEQUOIA DELICATULA Fontaine Sequoia delicatula Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 247, pl. cxxi, fig. 3. Sequoia delicatula Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 310. Description.—* Principal twigs slender, penultimate and ultimate ones all in one plane, minute, short, closely placed, alternate and pinnate *Saporta, Fl. Foss. Portugal, 1894, p. 177, pl. xxxiii, figs. 7-12. MaryLanp GEOLOGICAL SuRVEY 449 in arrangement; leaves very small, narrowly linear, acute or acuminate, widest at base, decurrent, and mostly crowded; midnerve slender but distinct.”—Fontaine, 1890. Fontaine says of this species: “This plant is a good deal like S. subulata, but the leaves are proportionately wider and not so falcate, while the ultimate branches are placed at more uniform intervals.” It may be doubted whether it is really distinct from the abundant Sequoia Reichenbachi since it was extremely rare at the single Virginia locality from which it was originally collected and it has not been met with in any of the subsequent collections. It is not especially well marked and is of little significance although it has seemed best to keep it distinct at the present time. Occurrence-—PaTUXENT Formation. Near Dutch Gap. Virginia. Collection.—U. S. National Museum. SEQquora AMBIGUA Heer Plate LXXVIII, Figs. 1-7 Sequoia ambigua Heer, 1874, Fl. Foss. Arct., Band iii, Abth. ii, pp. 78, 91, pl. xxi, figs. 1-11; pl. xxv, fig. 5. Sequoia ambigua Heer, 1882, Ibid., Band vi, Abth. ii, pp. 17, 52, pl. i, fig. 3. Sequoia ambigua Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1880, p. 245, pl. cxviii, fig. 2; pl. cxx, figs. 1-6; pl. exxvii, fig. 5; pl. cxxxii, fig. 3. Sequoia ambigua White, 1890, Am. Journ. Sci., vol. xxxix, p. 97, pl. ii, figs. 2,3 Sphenolepidium recurvifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 258, pl. cxxvii, fig. 2; pl. cxxx, figs. 2, 7. Sphenolepidium dentifolium Fontaine, 1890, Mon. U. 8S. Geol. Survey, vol. Xv, 1889, p. 258, pl. cxxvilii, figs. 2-6; pl. exxix, fig. 5; pl. cxxx, figs. 4-6, 10. Sequoia ambigua Nathorst, 1893, in Felix and Lenk, Beitr. z. Geol. u. Padleont. Repub. Mexico, ii,Theil, 1 Heft, p. 51, figs. 1-3. Sequoia ambigua Hollick, 1895, Bull. Geol. Soc. Am., vol. vii, p. 138. Sequoia gracilis Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, p. 675, pl. clxvi, fig. 2 (non Heer). Sequoia ambigua Uhler, 1901, Trans. Md. Acad. Sci., vol. i (1892), p. 207. Sequoia ambigua Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 272, 281, 538, 555, pl. Ixix, fig. 6; pl. cx, fig. 18. 450 : SYSTEMATIC PALEONTOLOGY Sphenolepidium dentifolium Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 484, 528, 538, 546, 555. -Arthrotaxopsis expansa Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xv, 1889, pp. 538, 585, 538, 555, 578, pl. cix, figs. 12, 18 (non pp. 504, 520, 547, 571). Sequoia ambigua Hollick, 1907, Mon. U. S. Geol. Surv., vol. 1, p. 41, pl. iti, figs. 7, 8. Sequoia ambigua Knowlton, 1907, Smith. Misc. Coll., vol. iv, pt. i, 1907, p. 126. Sequoia ambigua Berry, 1910, Bull. Torrey Club, vol. xxxvii, p. 20. Sequoia ambigua Berry, 1911, Proc. U. S. Natl. Mus., vol. xl, p. 310. Description.—* 8. ramis elongatis, foliis omnino tectis, ramulis alter- nis, gracilibus, foliis decurrentibus, brevibus, crassiusculis, falcato- incurvis, apice acuminatis, uninerviis, strobilis globosis, squamis peltatis, planiusculis.”’—Heer, 1874. Remains of the foliage of this species are distinguishable from those of contemporaneous conifers, which occur in the beds with them, by the relatively short and very stout, acuminate, falcate or recurved, decur- rent leaves. ‘ The cones are spherical and consist of relatively few short scales with longitudinally striated peduncles and suddenly expanded, quadrangular, peltate, umbilicate tips. These cones are abundant in the Lower Cre- taceous of Maryland occurring usually as detached ferruginized mud- casts. They vary considerably in size and this has resulted in their having been referred to two species and genera, the smaller having been. identified by Professor Fontaine as Arthrotaxopsis expansa while the larger were referred to Sequoia ambigua. As Prof. Ward pointed out in Monograph XLVIII they show no differences except in size, and even this feature has rather narrow limits of variation with every grada- tion present. The writer has carefully compared a large suite of speci- mens and many wax casts of the scales and finds them absolutely identical in every respect, the relative proportions of the scales from the smallest and the largest cones giving the same ratios of length, width, and height. As recorded in the literature cited above Sequoia ambigua is widely distributed geographically and-it has an equally great geological range. MARYLAND GEOLOGICAL SURVEY 451 Described originally from the Kome beds (Barremian) of Greenland by Professor Heer this author soon afterward recorded it from the Upper Cretaceous Atane beds of that country. It has been recorded by Nathorst from-the Neocomian of Mexico and it is present in the. Kootanie formation of Montana. It is a member of the Shasta flora of the Pacific coast (Horsetown beds) and is probably represented in the Fuson formation of eastern Wyoming by what Prof. Fontaine calls Sequoia gracilis. In the Upper Cretaceous, remains in every way identical with these Lower Cretaceous occurrences are present in the Magothy formation at Gay Head and at a number of localities in Maryland as well as in the Tuscaloosa formation of Alabama. In the Potomac Group this species ranges from the base of the Patux- ent, through the Arundel to the top of the Patapsco in considerable abundance. Seward (Wealden: Fl. pt. ii, 1895, p. 206) comments on the resemblance between Sequoia ambigua Heer and the widespread remains of Sphenolepis Sternbergiana (Dunker) Schenk, a resemblance strikingly shown in some Wealden specimens of the latter from Eccles- bourne recently received by the writer. However, their preservation is not of the best and the English specimens seem to show slight differ- ences from the type of this species in the direction of what in America is identified as Sequoia ambigua. No changes in nomenclature are pro- posed, however, since it seems probable that Sphenolepis Sternbergiana in North America is properly identified and distinct from Sequoia ambigua, which is more open and stouter and which may be present in the English Wealden in some at least of the coniferous twigs identified as Sphenolepis Sternbergiana. Occurrence.—PatuxEnT Formation. Fredericksburg, Dutch Gap, Cockpit Point, Potomac Run, Telegraph Station (Lorton), Virginia. ARUNDEL Formation. Soper Hall, Riverdale, Arlington, Muirkirk, Schoolhouse Hill (Hanover), Maryland. Parapsco Formation. Federal Hill (Baltimore), Locust (Poplar) Point, Fort Foote, Maryland. Collections —U. S. National Museum, Johns Hopkins University. 452 SyYsTEMATIC PALEONTOLOGY cass ANGIOSPERMAE Subclas MONOCOTYLE DONAE Order NAIADALES Family ALISMACEAE Genus ALISMAPHYLLUM gen nov. The present genus is proposed for monocotyledonous leaves of un- known generic affinity but obviously referable to the family Alismacee. The type species is Sagittaria Victor-Masoni Ward based on a single specimen from the Patapsco formation at Mt. Vernon, Virginia. It was compared by its describer with the exisiting Sagittaria latifolia Willd., but it would be equally at home in other genera, as for example Echinodorus or Lophotocarpus to mention but two such. The venation is of the type of this family and the auricles suggest various species of Sagittaria, although when auricled the ears in the mature leaves are usually much more extended than in the fossil leaf. Since, however, there is considerable variation in this respect, some species having lanceolate leaves and others like Sagtttaria rigida Pursh having linear, lanceolate, elliptical and hastate leaves, this character is not of impor- tance. It is believed, however, to be of distinct advantage in cases where certainty is impossible, not to carry the generic lines of the present too far back into the past. The genus Alismacites of Saporta* is not available since it was proposed for forms with a distinctly stated relation- ship to the modern genus Alisma. A considerable number of fossil species from a large number of horizons have been described as species of Alisma, Alismacites and Sagittaria, the oldest being the leaves and seeds from the Neocomian of Portugal which Saporta names Alismacites primevus.’ The existing Alismacee number about 70 species segregated into 10 or 12 genera and all are aquatic or marsh plants of herbaceous stature +Saporta, Ann. Sci. Nat. Bot. (iv), tome xvii, 1862, p. 228. *Saporta, Fl. Foss. Portugal, 1894, p. 96, pl. xv, fig. 31; pl. xvi, fig. 18a. MARYLAND GEOLOGICAL SURVEY 453 and wide distribution, representatives being present on all the continents. They seem equally at home in the tropics and in the less cold parts of the temperate zone and with favorable edaphic conditions seem to be but little influenced by those of temperature ALISMAPHYLLUM VicTor-Mason1 (Ward) Plate LXXIX, Fig. 5 Sagittaria Victor-Masoni Ward, 1895, Fifteenth Ann. Rept. U. S. Geol. Sur- vey, p. 354, pl. iii, fig. 5. Sagittaria Victor-Masoni Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 491. Description.—Leaf ovate in outline tapering upward and presumably acutely pointed, auriculate below. Auricles relatively short, wide and rounded, margin entire. Petiole and midrib stout. Secondaries four to six in number, from the top of the petiole, one or two on each side reflexed and supplying the auricles, the two inner on each side curving upward, the outer following the margin for a considerable distance, how far it is not possible to ascertain since both of the lateral margins are inrolled in the single known specimen of this species. The finer vena- tion is unfortunately not preserved. This species is clearly referable to the family Alismacee and while it shows a number of characters which ally it with the modern genus Sagittaria it is equally close to other modern and closely related genera as has just been pointed out, so that its reference to a genus which while denoting its general botanical affinity does not carry implications of identity with any of the existing genera of this family is clearly demanded. The species is obviously distinct from any previously described fossil forms but is unfortunately based on the single specimen figured so that a more complete diagnosis is impossible. Occurrence.—Patarsco Formation. White House Bluff, Virginia. Collection.—U. 8. National Museum. 454 SysTeMATIC PALEONTOLOGY Order GRAMINALES Family CYPERACEAE Genus CYPERACITES Schimper [Pal. Végét., tome ii, 1870, p. 412] This genus was proposed by Schimper for those fossil remains includ- ing fragments of rhizomes, culms, leaves, inflorescences, fruits, etc., whose reference to the family Cyperacer seems justified, but which cannot be satisfactorily compared with any of the existing genera of that family. It is strictly a form genus and was designed to replace the genus Cyperites of Heer since the latter name as originally proposed by Lind- ley and Hutton was applied to carboniferous leaves of Sigillaria. Schim- per in 1870 (Joc. cit.) listed 33 species of Cyperacites and about as many more have been described since that date, nearly all coming from Ter- tiary sttata. Some doubtful remains of parallel-veined leaves from the Upper Cretaceous have, however, been referred to this genus. The Lower Cretaceous records are similar to those of the Upper Cretaceous and are very indefinite in character; they include certain vague material recorded by Dawson* from the Kootanie of British Columbia and two types of leaves recorded by Heer” from the Kome beds of Greenland. The following species from the Patapsco formation of Maryland, while it leaves much to be desired, is of considerable interest, since it is by far the oldest known sedge which has been preserved with sufficient of its parts to render its reference to this family certain. While remains of sedges and grasses showing flowers or fruits are not unknown in the fossil state all have come from comparatively recent deposits, that is to say, late Eocene or younger. The family Cyperacee in the existing flora is a large one with several thousand spécies distributed among about 70 genera, of which the ubiquitous genus Carex is by far the largest. The species are chiefly temperate in habitat but many of them have a very wide range. * Dawson, Trans. Roy. Soc. Can., vol. x, sec. iv, 1892, p. 91, tf. 16. * Heer, Fl. Foss. Arct., Band iii, 1874, p. 86, pl. xii, fig. 4b; pl. xxiv, fig. 4. MARYLAND GEOLOGICAL SURVEY 455 CYPERACITES POTOMACENSIS sp. nov. Plate LXXIX, Fig. 6 Description.—Plants of small size, with slender, somewhat flabellate, linear leaves. Culm slender, apparently flat, preserved for a length of 2.2 cm. (apical part missing) and bearing 1.6 cm. from the base, a single fruiting head, the subtending bract being apparently reduced to a small scale. Head oblong conical, about 5 mm. in length and 2 mm. in width as preserved with a short peduncle about 1 mm. in length. Achenes relatively few in number, apparently angular, much flattened. The associated leaves are flat and slender, about 1/3 of a millimeter in width. This species is based upon the specimen figured and its counterpart, comprising the culm with the attached fruits and the more or less broken remains of four leaves, apparently belonging to the same indi- vidual as does the culm. It was evidently a small and delicate form and not a young plant since the achenes must have been nearly or quite mature to have left such sharp impressions in the clay. The preserva- tion is such that no details can be made out but it is clearly referable to the sedges and might be matched by a number of modern species of Carex. As previously mentioned it is of considerable interest in that it furnishes conclusive evidence of the existence of this supposed modern family of Monocotyledone at an age as remote as the late Lower Cre- taceous and it is of further interest, even preserved as poorly as it is, in representing a fruiting specimen of these comparatively rare types. Occurrence.—Patapsco Formation. Near Wellhams, Anne Arundel County, Maryland. Collection.—Johns Hopkins University. 456 Systematic PALEONTOLOGY Order XYRIDALES (?) Genus PLANTAGINOPSIS Fontaine [In Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1906, p. 560] PLANTAGINOPSIS MARYLANDICA Fontaine Plate LXXIX, Figs. 1-4; Plate LXXX Plantaginopsis marylandica Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xIviii, 1905, p. 561, pl. exvii, fig. 7; pl. exviii, figs. 1, 2. Celastrophyllum marylandicum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 559, pl. exvi, fig. 7. Description.—Leaves elongate linear-lanceolate, 10 to 18 cm. in length by about 2.5 cm. in width at the broadest part which is toward the apex, from which point they narrow gradually to the broad sheathing base. The latter is about 5 mm. wide with the margins approximately parallel and is the part usually preserved, the upper and more delicate part of the leaf lamina having usually been completely macerated or torn away before fossilization. Margins entire basally for 1/3 the length of the leaf, and for even a greater distance, passing distad into slight serrations which gradually grade into large, shallow, rather rounded, dentate teeth. Apex not clearly made out but apparently rounded. Venation indistinct; basally there are several approximately parallel veins of rather fine calibre, higher up in the lamina these branch in a straggling manner and apparently send short branches into the teeth. Several specimens of the capitate fruit (inflorescence ?) are preserved in intimate associa- tion but not in actual connection with the leaves. These fruits are ellipti- cal in shape, as preserved they are about 2.5 cm. x1.2 cm., the surface covered with more or less circular bosses of small size about 1 mm. in diameter, somewhat suggestive of the berry-like fruits of the Aracezx. Five specimens in all have been found and a sixth from the same locality has received the name Celastrophyllum marylandicum. This latter shows the venation of the upper part of the leaf, but not at all clearly, nor are the veins as prominent as the published figure would indicate. It has the same narrow outline, broad entire base, large irregu- MARYLAND GEOLOGICAL SURVEY 457 lar teeth and is undoubtedly referable to this same species another leaf of which is preserved alongside of it on the same piece of clay. There is no obvious relation to Celastrophyllum the absence of a definite midrib at once removing that genus from consideration. The plant evidently was stemless from a rootstock as the larger specimen figured would indi- cate and was evidently a semi-aquatic marsh plant comparable with Eriocaulon, Fontaine’s comparison with Plantago emphasized by the name being particularly unfortunate. Occurrence—Patapsco Formation. Federal Hill (Baltimore), Maryland. Collections—U. 8. National Museum, Goucher College.. Subclass DICOTYLEDONAE Order SALICALES Family SALICACEAE Genus POPULUS Linné [Sp. PL, 1753, p. 1034] Trees with narrow lanceolate to broadly orbicular, alternate, stipu- late, generally long petiolate leaves. Margins sometimes entire but usually toothed in various ways. Venation pinnate in the modern and in a large number of the fossil species, the secondaries being approxi- mately parallel and the basal pair not of sufficiently disproportionate size to be termed primaries. In numerous fossil species, however, especially those from the Arctic regions and from the earlier American deposits, the basal secondaries are prominent and curved upward, war- ranting the use of the term palmate in describing them.. Fruit a 2 to 4 valved capsule, the enclosed seeds with a conspicuous long coma of white silky hairs, both fruit and seeds occurring as fossils under especially favorable conditions of preservation. The genus Populus is an important one for the paleobotanist with over 150 described species, the oldest of which, the celebrated Populus 458 Systematic PALEONTOLOGY primeva of Heer} from the Kome beds (Barremian) of Greenland, still remaining one of the oldest known dicotyledons of undisputed identity. Two other species described by Heer from the Arctic Tertiary, Populus Zaddachit and Populus arctica have the further distinction of having been found fossil in latitude 81° 46’ on the north shore of Grinnell Land. The Potomac species comes next after Populus primeva in point of age. With the dawn of the Upper Cretaceous a number of species appear including four in the Atane beds of Greenland, ten in the Dakota sand- stone and four or five in the Raritan, Tuscaloosa and Magothy forma- tions. The first European species appear to be of Senonian age. After the close of the Cretaceous the genus expanded suddenly, especially in America, over a score of species being known from the Fort Union beds and many from the Arctic Tertiary. It remained cosmopolitan in the northern hemisphere throughout the Tertiary and Recent periods, and several of the existing species, which number in all about 25 forms, are present in the Pleistocene deposits of both America and Europe. PoPruLUS POTOMACENSIS Ward Plate LXXXI, Figs. 1-le Populus potomacensis Ward, 1895, 15th Ann. Rept. U. S. Geol. Survey, p. 356, pl. iv, figs. 1-3. Populus auriculata Ward, 1895, 15th Ann. Rept. U. S. Geol. Surv., p. 356, pl. iv, fig. 4. Populophyllum menispermoides Ward, 1906, in Fontaine, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 498 (pars), pl. ex, fig. 2 (mon figs. 8, 4). Populus auriculata Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol. xviii, 1905, p. 499, pl. ex, fig. 5. Populus potomacensis Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 500. : Description.—Leaves of small size, orbicular to ovate in general out- line, with an obtusely pointed apex and a broad, deeply cordate base. 2 em. to 5.5 cm. in length by 2.2 cm. to 4 cm. in greatest width, which *Heer, Fl. Foss. Arct., Band iii, Abth. ii, 1874, p. 88, pl. xxiv, fig. 6. MaryLaNnp GEOLOGICAL SURVEY 459 is in the basal half of the leaf. Margin crenulate, entire in the basal sinus. Petiole stout. Midrib of medium calibre. Primaries 3 to 7 in number decreasing in calibre outward, inserted at the apex of the petiole, curving upward, camptodrome. This characteristic and handsome little species is abundant in the Mt. Vernon clays to which locality it is thus far confined. It shows’ considerable variation in the amount of elongation, some specimens being relatively narrow with a consequently more pointed apex and more acute basal sinus, but there can be scarcely any doubt that the forms figured were all borne by the same tree, although they constituted a part of three different species of Professor Ward, as enumerated above. The outlines of Populus leaves in general vary considerably in the same species and on the same tree. The venation on the other hand is more conservative, and it is on the basis of these well-known facts that the present treatment is based. Occurrence—Patarsco Formation. Mt. Vernon and White House Bluff, Virginia. Collection —U. 8. National Museum. Genus POPULOPHYLLUM Fontaine {Mon. U. S. Geol. Survey, vol. xv, 1890, p. 311] This genus named to indicate a supposed but altogether doubtful relationship with the genus Populus is characterized as follows by its describer :. “Leaves rotundate; petiole thick and apparently somewhat succulent; nerves tending to a radiate grouping from- the summit of the petiole; midnerve not much surpassing in strength the nerves which go off on each side of it.” As here understood the genus embraces two species, one with an entire or slightly undulating margin and the other with a coarsely dentate margin. It may be doubted whether the two are congeneric, the former certainly shows but the slightest affinity with Populus and suggests the genus Chondrophyllum. Similar remains from the Lower Cretaceous 460 SystTEMATIC PALEONTOLOGY of Portugal are referred by Saporta to the genera Menispermites and Aristolochia. PopuLOPHYLLUM MINUTUM Ward Plate LXXXI, Fig. 2 Populophyllum minutum Ward, 1906, in Fontaine, Mon. U. 8. Geol. Survey, vol. xlviii, 1905, pp. 499, 532, pl. evii, fig. 9; pl. eviii, fig. 11. Description.—Leaf nearly orbicular in outline; small in size, being about 1.5 cm. in length and width. Margin coarsely dentate, becoming entire toward the base which is not at all cordate or auriculate, but rounded truncate or cuneate. Venation palmate; primaries three to five in number from the summit of the petiole, the midrib being much the strongest. The lateral primaries are fine in calibre, they fork and anastomose some distance from the margin sending very delicate branches into the broad blunt teeth. As Professor Ward remarks (loc. cit.), this leaf is suggestive of the Vitacee and recalls Cissites crispus Velen. from the Bohemian Cenoma- nian and the forms which Newberry described under the same name from the New Jersey Raritan. It is abundantly distinct from all of these, however, and were the present author describing it de novo, it would be referred to Populus. As the case stands it may remain in Populophyllum which sufficiently indicates its probable affinity and does not necessitate a change in nomenclature. More representative specimens of this species occur on the southern bank of the Potomac at Mt. Vernon, the fragments from Ft. Foote being not entirely satisfactory, suggesting the possibility that they might be small and somewhat anomalous leaves of Celastrophyllum acutidens Font., which is so abundant at this locality. They appear, however, to be identical with the Mt. Vernon material. Entirely characteristic leaves of this species occur in the Maryland Patapsco deposits near Wellhams. These are identical.in appearance with those from Mt. Vernon, Virginia, except for a somewhat narrowed base coupled with which character the outer lateral primaries have migrated upward slightly and become basal secondaries. MARYLAND GEOLOGICAL SURVEY 461 Occurrence.—Patapsco Formation. Ft. Foote, Prince George’s County, near Wellhams, Anne Arundel County, Maryland; Mt. Vernon, Virginia. Collection.—U. S. National Museum. PoPpuULOPHYLLUM RENIFORME Fontaine Plate LX'XXI, Figs. 3-6 Populophyllum reniforme Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 311, pl. clv, fig. 9; pl. elvi, fig. 3. Populophyllum hedereforme Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 311, pl. elxvi, fig. 3. Proteephyllum reniforme Ward, 1895, 15th Ann. Rept. U. S. Geol. Survey, p. 360, pl. iv, figs. 5, 6 (non Font.). Populophyllum menispermoides Ward, 1906, in Fontaine, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 498, pl. cx, figs. 3, 4 (non fig. 2 which is Populus potomacensis Ward). Description.—Leaves of small or medium size, orbicular or reniform in outline, 3 cm. to 7 cm. in length by 3 cm. to 7 em. in greatest width which is about half way between the apex and the base. Margin entire or slightly undulate. Petiole very stout, of considerable length. Vena- tion palmate, camptodrome. Primaries 4 to 7 from the top of the petiole, usually 7 in number, very fine in calibre and often invisible, the midrib slightly more prominent than the lateral primaries; these soon fork and anastomose in broad arches sending off branches which form similar secondary and tertiary arches. Basal sinus shallow with the basal auricles of the leaf lamina uniformly rounded, ranging to forms in which the sinus is narrow and as much as 2 cm. deep with the auricles of the lamina somewhat angular. This curious species is especially common, although usually in a fragmentary condition, in the Patapsco beds in the vicinity of Aquia Creek, Virginia. It is scarcely related to Populus and by its thick petiole and fine venation is suggestive of an aquatic plant. Mention has already been made (supra) of its resemblance to some of the forms referred to the genus Chondrophyllum but this gives no better clue to its botanical affinity. In Portugal Saporta has described similar remains from the Albian beds of Buarcos under the names Menispermites cerei- 462 SysTEMATIC PALEONTOLOGY difolius* and Aristolochia Daveauana.’ The latter form is undoubtedly congeneric with the Patapsco species but it is extremely doubtful if Aristolochia is even as near an expression of its generic affinities as Popu- lophyllum. The present species should also be compared with the Kome plant which Heer described as Protorhipis cordata*® which is obviously not a Protorhipis and is closely related to this Patapsco species. Occurrence-—Patapsco Formation. Mt. Vernon, 72-mile post near Brooke, White House Bluff, near Widewater, just north of Aquia Creek on the R. ¥F. & P. R. RB. and just south of Aquia Creek on the R. F. & P. R. R.. (common), Virginia; near Wellhams, Anne Arundel County, Maryland. Collections.—U. S. National Museum, Johns Hopkins University. Order RANALES Family NYMPHAEACEAE Genus NELUMBITES gen. nov. The Potomac forms referred to this genus have hitherto been referred to Menispermites a comprehensive genus belonging to the allied family Menispermacez of ‘this order. The oldest species of Nelumbo-like leaves heretofore known include the small leafed Nelumbo primeva Berry * from the Magothy formation of New Jersey and Maryland which should probably be referred to this gerfus and the large leafed Nelumbo Kempii Hollick® from the same formation in New Jersey and on Long Island and Marthas Vineyard. Small leafed forms also occur at higher horizons in the Montana Group and in the Laramie or Shoshone Groups of the West. Still other and ‘mostly larger species are referred to the allied genus Nelumbium of Jussieu. +Saporta, Fl. Foss. Portugal, 1894, p. 191, pl. xxxv, fig. 7. ? Saporta, Ibid., p. 183, pl. xxxv, fig. 10. * Heer, Fl. Foss. Arct., Band vi, Abth. ii, 1880, p. 10, pl. iii, fig. 11. ‘Bull. N. Y. Bot. Garden, vol. iii, 1903, p. 75, pl. xliii, fig. 1. *Mon. U. 8. Geol. Surv., vol. 1, 1907, p. 61, pl. xiii, figs. 1-4; pl. xiv, figs. 1, 2; pl. xv; pl. xvi, figs. 1-6. MARYLAND GEOLOGICAL SURVEY 463 While the Potomac species have the characteristic peltate leaves they are not radially symmetrical as are the later species but have the petiole attached nearer to one margin giving them an appearance much like that of a number of supposed species of Menispermites. The venation is, however, nearer that of Nelwmbo and its allies, the secondaries being prominent on the lower surface, obsolete on the upper surface, and fork- ing after the manner of the Nymphzacee. If these leaves were not floating it is surprising that a petiole stout enough to hold the leaf erect is not found fossil, unless the leaf normally abscissed from the apex in- stead of the base of the petiole. It is hoped that sooner or later specimens will be found showing whether or not the stomata were confined to the upper surface and thus confirming or disproving the assumption here made that they were aquatic in habit. The author has followed Fontaine in keeping the two following species separate, although they are very similar except as to size and the resulting calibre of venation, and it would have done little violence to the facts to have united them in a single species. They are characteristic forms of the Patapsco formation and quite abundant at certain outcrops. The existing species of Nelwmbo are two in number, both large aquatic perennials, one North American and the other Asiatic and Australian. Tt has seemed better to establish a new genus for the reception of these older Cretaceous forms, which while expressing their proper affinities does not unduly extend our conception of the modern genus. It is interesting to note in this connection that Saporta* has reported two species of Nelumbiuwm from the supposed Albian of Portugal, but as these are not fully defined and unfigured their relation to the following American species is unknown. NELUMBITES VIRGINIENSIS (Fontaine) Berry Plate LX XXII, Figs. 3-5 Menispermites virginiensis Fontaine, 1890, Mon. 17 S. Geol. Surv., 1889, vol. xv, p. 321, pl. clxi, figs. 1-2. 1Saporta, Comptes rendus, tome cxix. 1894, pp. 835-837. 30- 464 SYSTEMATIC PALEONTOLOGY Menispermites virginiensis Ward, 1895; 15th Ann. Rept. U. S. Geol. Surv., . p. 360, pl. iv, fig. 8 (non fig. 7). Menispermites virginiensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Sur- vey, vol. xlviii, 1905, pp. 504, 528, 534, 557. Description.—The type of this species from near Brooke, Va., is a fragment of a large leaf about 15 cm. in diameter. The preservation is such that its peltate character cannot be made out with certainty the specimen having the appearance of having a deeply auriculate overlap- ping base, but this is probably due to maceration or folding, as the additional specimens since found which resemble it very closely are distinctly peltate. General outline orbicular, about 10 cm. in diameter; leaf substance thick; margin inclined to be undulate or obscurely crenulate. Point of attachment to the petiole about 1/3 of the diameter distant from the margin. Veins radiate, somewhat flexuous, stout, nine or ten in number, dichotomously forking. This species is very suggestive of certain Dakota Group forms which Lesquereux described as species of Menispermites, e. g., M. grandis and M. cyclophyllum. Poorly preserved remains have been found at a number of localities in Virginia and Maryland in beds of Patapsco age, and its resemblance to NV. primeva Berry from the Magothy formation suggests an ancestral relationship. Oceurrence.—Patapsco Formation. Ft. Foote (?), Federal Hill (Baltimore), Overlook Inn Road, Maryland; Mt. Vernon, Hell Hole, %2-mile post, Brooke, Virginia. Collections——U. S. National Museum, N. Y. Botanical Garden and Goucher College. NELUMBITES TENUINERVIS (Fontaine) Berry Plate LX XXII, Figs. 1, 2 Menispermites tenuinervis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 322, pl. clxii, fig. 8. Menispermites virginiensis Ward, 1895, 15th Ann. Rept. U. S. Geol. Surv., p. 360, pl. iv, fig. 7 (non fig. 8). Menispermites tenuinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 496, 557, pl. cix, figs. 2, 3. MARYLAND GEOLOGICAL SURVEY 465 Description —The type of this species was a small, thick, orbicular leaf with obscure venation from’ Federal Hill which the describer com- pared with a Lemna. The same author has identified this species in more recent collections and it is from these that the present description is drawn since the original type presents no distinctive characteristics. Leaves peltate, considerably smaller than those of the preceding species, not over 7 cm. in maximum diameter, orbicular in outline, the transverse somewhat greater than the longitudinal diameter. Margin entire or obscurely undulate. As might be expected from the com- parative size, the veins are finer and the leaf substance is thinner than in NV. virginiensis. Veins radiating from the eccentric point of attach- ment of the petiole, about seven in number, thin and somewhat flexuous, forking and forming transverse loops parallel with the margin. These loops send off almost rectangular branches forming a secondary series of loops parallel with the margin. Similarly a third and smaller series may be present. Veins obsolete on the upper surface of the leaf but prominent below. This species is not strikingly different from the preceding, its specific characters possibly being due entirely to its smaller size, although the attachment to the petiole is nearer the margin, the transverse diameter is proportionately greater, and there is a more definitely marked midrib than in N. virginiensis. Occurrence—Patapsco Formation. Federal Hill (Baltimore), Maryland; Mt. Vernon, Aquia Creek, White House Bluff, Virginia. Collection.—U. 8. National Museum. Family MENISPERMACEAE Genus MENISPERMITES Lesquereux [U. S. Geol. Surv. Terr., vol. vi, 1874, p. 94] The genus Menispermites was erected by Lesquereux in 1874 for the reception of four species of leaves from the Dakota sandstone of the West, which he had previously referred to Dombeyopsis, Acer or Acerites, and Populites. His diagnosis was as follows: 466 SYSTEMATIC PALEONTOLOGY “Leaves large, coriaceous or subcoriaceous, broadly deltoid, more or less distinctly three-lobed, with obtuse divisions, and borders entire or undulate; nervation palmately 3 to 5 nerved, from a peltate or subpel- tate, truncate or subcordate base; primary veins craspedodrome, their points joining the borders of the lobes, but their divisions following along them by a series of curves upon each other, or of multiple festoons, as seen in the leaves of the present Menispermum canadense especially. The divergence from this last type is marked in one species only, whose nervation agrees with that of Menispermum (Cocculus) carolinum,” ete. The craspedodrome character of the venation or the lobate character of the lamina cannot be insisted upon since Lesquereux and others have referred a number of camptodrome and entire forms to this genus. Later exploration in the Dakota sandstone enabled Lesquereux and others to characterize five additional species from this horizon, one of which has been reported from the Coastal Plain. Heer has described two species from the Atane beds of Greenland, one of which extends southward to the Raritan of New Jersey. This species in all but its more pointed apex closely resembles the following Patapsco species. Three other species have been described from the Atlantic Coastal Plain and several are known from the Upper Cretaceous of the West, while Saporta has described a single species from the Albian of Portugal. Fontaine records this genus from the Shasta flora of the Pacific coast but the remains are altogether uncharacteristic. The species from the Potomac Group which were formerly referred to this genus by Fontaine are discussed under the genus Nelumbites in the present work. MENISPERMITES POTOMACENSIS sp. nov. Plate XCITI, Figs. 3, 4 Description.—Leaves of relatively medium or small size, orbicular in general outline. Length 6 cm. to 9 cm. Greatest width 5 em. to 8 cm. at a point about half way between the apex and the base. Margin entire, more or less undulate. Apex rounded. Base rounded, ultimately slightly decurrent and possibly inclined to cordate in some specimens. Maryann GroLtogicaL SurvEY 467 Venation palmate from at or near the base. Midrib slender, somewhat flexuous. Lateral primaries three to five pairs, spreading at acute angles, ultimately camptodrome by curving inward to join secondary branches of the next within primary. This species is very close to the later-species which have been referred to Menispermites but it is clearly distinct from any of these. It is also separated by well-marked characters from the Potomac species of Nelum- bites which resemble it in a general way. . Occurrence.—Patapsco Formation. Stump Neck, Maryland; Wide- water, Virginia. Collection—Johns Hopkins University. Order SAPINDALES Family SAPINDACEAE Genus SAPINDOPSIS Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 296] “Leaves pinnate, both odd pinnate: and abruptly pinnate; terminal leaves usually more or less united at base; upper pai1s of leaves decur- rent, forming a wing on the common stem, the wing lessening in width on the pairs in descending; leaves mostly opposite in pairs, sometimes subopposite; the lowest pairs lack the wing, and are sometimes short- petioled; leaves thick, with dense and often glossy epidermis, elliptical or lancet-shaped, with a strong prominent midrib, which extends with slight diminution to the tip of the leaf; lateral nerves going off at a large angle, and uniting more or less completely near the margin to form a series of arches; the lateral or primary nerves, as seen on the lower side of the leaves, strong and prominent, but on the upper side, owing to the thickness of the leaves, generally indistinct; the ultimate reticula- tion is strong, and forms a series of rather large, irregular, polygonal meshes.”—Fontaine, 1890. This curious genus forms an important element in the flora of the Patapsco formation to which it is strictly confined with the single excep- tion that 8. variabilis has been recorded in the nearly homotaxial Fuson 468 SYSTEMATIC PALEONTOLOGY formation of Wyoming. No specimens of Sapindopsis are known from either the Patuxent or Arundel formations or their equivalents in other parts of North America. It is true that Professor Fontaine described Sapindopsis cordata from Fredericksburg, Virginia, but this material, which is very poor, is obviously not related to this genus, while the record of Sapindopsis elliptica from Fredericksburg by the same author is based upon the remains of Rogersia longifolia Fontaine. The genus is notably absent from the fossiliferous Patapsco beds at Federal Hill, Md., but when present at a locality it usually occurs in the greatest abundance, as at Fort Foote, Maryland, or in the vicinity of Brooke, Virginia, where hundreds of specimens often of great perfection have been collected. In modification of the diagnosis quoted above, it may be said that the vast tnajority of the leaves are abruptly pinnate and the terminal leaflets while usually confluent and decurrent are sometimes petiolate, Sapin- dopis magnifolia in particular furnishing many individuals lacking the decurrently winged rachis. The most closely related plants to Sapindopsis in the modern flora are the various genera of American tropical Sapindacee. Among these the genus Matayba Aubl. approaches very near to the Cretaceous form. Matayba embraces species with both opposite and alternate leaflets hav- ing either entire or dentate margins. The rachis lacks definite ale but it is somewhat flattened with a vestigial wing on each side in the form of a raised line which is wider at the point of origin of the leaflets and decurrent to the next lower leaflets. So many other genera of the Sapin- dacew have markedly alate rachises that the presumption is strong that this genus or its ancestors were at some time similarly provided. The most similar species seems to be Matayba apetala (Macf.) Radlk., in which the leaflets are usually more numerous than in Sapindopsis although some specimens show but 3 pairs, those with 4 pairs are common; they are sometimes subopposite and as many as 7 pairs are met with. The venation is exactly like that of the fossils as is the texture of the leaves and their limits of variation. Another closely related species is Matayba Domingensis Radlk., also a native of the West Indies. MARYLAND GEOLOGICAL SURVEY 469 ¥ It is exceedingly satisfactory to be able to establish upon a somewhat firmer basis Professor Fontaine’s choice of the term Sapindopsis for these Potomac plants. They are so abundant in their occurrence, so striking in appearance, their strict habit and glossy texture giving them every appearance of some fern-like plant as for example the common Acrostichum aureum of the tropics, that their original describer deserves great credit for having correctly determined their modern affinities. SAPINDOPSIS VARIABILIS Fontaine Plates LXXXITI, LXXXIV, LDXXXV Sapindopsis variabilis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 298, pl. cli, fig. 1; pl. clii, figs. 1, 4; pl. cliii, fig. 3; pl. cliv, figs. 2-4; pl. clv, figs. 2-5. Sapindopsis parvifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 300, pl. cliv, fig. 6. Sapindopsis variabilis Fontaine, 1899, in Ward, 19th Ann. Rept. U. S. Geol. Survey, pt. ii, p. 690, pl. clxix, fig. 9. Sapindopsis variabilis Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey., vol. xlviii, 1905, pp. 481, 482, 489, 532, pl. exiv, fig. 2. Eucalyptus rosieriana Ward, 1906, in Fontaine, Mon. U. S. Geol Surv., vol. xlviii, 1905, p. 530, pl. cxiii, figs. 9, 10. Ficus myricoides Ward, 1906, in Fontaine, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 531, pl. cxii, fig. 12 (non Hollick, 1896). Rogersia angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 491, 510 (mon p. 521). Sapindopsis variabilis Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 641. Description—Leaves odd pinnate, sometimes abruptly pinnate, with three pairs of lateral leaflets, which may be opposite although usually there is a tendency toward a subopposite arrangement, markedly so in several specimens. Leaflets normally lanceolate, individuals of the same leaf about of a size, usually markedly decurrent, but variable in this respect. The proximal leaflets are always less decurrent than the pair next above and in some cases even have short petioles. The upper leaflets are remarkably variable, sometimes with an abnormal decurrent wing which joins the inner lamina of the next lower pair of leaflets, at other times the rachis entirely lacks a wing. The leaf may be ter- ' 470 SYSTEMATIC PALEONTOLOGY minated abruptly by a pair of leaflets variously coalesced or the three apical leaflets may be variously united, their lamina may be almost symmetrical or markedly inequilateral, their margins showing a tendency toward undulation and occasionally a leaflet is divided into a basal and an apical part by a sharp constrictidn on one side near the middle of the blade. Ranging in size from the small forms upon which Fontaine founded his species 8. parvifolia and which are 1.6 cm. long and 0.4 cm. wide to forms which approach §. magnifolia in size and are 10 cm. long and 1.5 cm. wide. The average dimensions of a large number of specimens are, however, 6 cm. to 7 cm. long by 1 cm. to 1.3 cm. wide. Leaves thick with smooth surface. Rachis and midrib stout. Vena- tion more prominent than in the other species but still very faint, with the exception of the secondaries which while fine are more conspicuous than in the other species. Secondaries forming a wide angie with the midrib, nearly straight for 2/3 of the distance to the margin where they bend sharply upward and join the secondary next above by a but slightly curved arch. As the secondaries are numerous and almost uni- formly spaced the venation has much the appearance of a Eucalyptus except that the marginal hem is much broader than in that genus. ‘This species-is exceedingly abundant at various localities in the Patapsco formation and is by far the most characteristic species of that formation, although ‘it has not been detected at certain other undoubted Patapsco horizons. It is the only species of the genus which has been recorded outside of the Maryland-Virginia area, occurring in the Fuson formation along Oak Creek, Wyoming, where it is the most abundant species found just as it is at White House Bluff, Brooke, and Aquia Creek, Virginia, and at Ft. Foote, Maryland. It is an exceedingly variable form in all its details, and as during maceration the most variable apical portion is the last to be destroyed, this variability is emphasized in fragmentary material such as that usually found at Fort Foote. When well preserved it furnishes most ° striking specimens as may be seen from the specimens reproduced photo- graphically. In life its rigid pinnate leaves and strict appearance must have made it a very striking member of the Patapsco flora. MARYLAND GEOLOGICAL SURVEY 471 Occurrence-—Patapsco Formation. Fort Foote, Maryland; Aquia Creek, near Widewater, Chinkapin Hollow (?), near Brooke, White House Bluff, Mt. Vernon, 72-mile post, Virginia. Collections—U. S. National Museum, Johns Hopkins University. SAPINDOPSIS MAGNIFOLIA Fontaine Plate LXXXVI; Plate LXXXVII, Fig. 4; Plate LXXXVIII Sapindopsis magnifolia Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 297, pl. cli, figs. 2, 8; pl. clii, figs. 2, 3; pl. cliii, fig. 2; pl. cliv, figs. 1, 5; pl. clv, fig. 6. ? Aralia dubia Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 314, pl. elvii, figs. 1, 7 (non Schimper, 1874). Sapindopsis obtusifolia Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 301, pl. clvi, fig. 13; pl. clix, figs. 3-6. Ficophyllum eucalyptoides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 294, pl. clxiv, figs. 1, 2. ‘Sapindopsis tenuinervis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 301, pl. cliii, fig. 1. ? Aralia Fontainei Knowlton, 1898, Bull. U. S. Geol. Surv., No. 152, p. 37. Sapindopsis magnifolia, Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 481, 482, 528. Sapindopsis tenuinervis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 489, 528. Ficophyllum eucalyptoides Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 489. Sapindopsis magnifolia Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 642. Description.—Leaves commonly odd-pinnate, although occasional abruptly pinnate forms occur, of considerable size, but somewhat variable however, in this respect. Leaflets 3 pairs, comparatively large, lanceolate, tapering almost equally toward apex and base, the latter inequilateral except in terminal leaflets, pointed, often lacking apical portions, length increasing proximad, averaging about 10 cm., longest seen 14 cm. (estimated), shortest 5 cm., width varying from 1.1 cm. to 3.2 cm., inequi- lateral, since the outer half of the lamina is broader than the inner half and is markedly decurrent. This feature is least emphasized in the basal leaves which may even have a considerable petiole, but becomes ‘increasingly pronounced distad, the terminal leaflets often forming a bilobate or trilobate whole with the outer margins broadly decurrent and 472 SysTeMATIC PALEONTOLOGY joining the lamina of the leaflet next below at the point of juncture of its inner margin with the rachis. Certain specimens show all of the leaflets petiolate, a feature largely emphasized in the specimen figured from Stump Neck showing three terminal leaflets with petioles 3 to 4 cm. in length. The leaflets in this species are much oftener petiolate and lacking in the winged rachis than in 8. variabilis in this particular closely resembling the modern Matayba apetala in which the rachial wings are vestigial. Leaf substance thick and leathery, epidermis firm and glossy. Leaflets commonly subopposite, often markedly so, forming an acute angle with the rachis. Midribs stout and prominent below. Secondaries slender, only seen on the under surface of the leaflets and even then made out with difficulty, 8 to 10 pairs, branching from the midrib at a rather wide angle especially in the central part of the leaf; the angle is more acute basally, curving upward ultimately to join a short branch of the secondary next above. Tertiaries fine, forming lax subrhombic areole where visible. This species is very common at certain localities within the Patapsco formation as for example at Stump Neck in Charles County, although at other outcrops of this same formation it has not been detected. This is notably the case in the Federal Hill deposits from which large collec- tions have been made without disclosing a single specimen. Evidently the species was local in its distribution which is emphasized by its total absence in any other Lower Cretaceous deposit either here or abroad. The grounds for the separation of this species from 8. variabilis are slight since both are variable and the larger forms of the latter are quite as large as the smaller forms of S. magnifolia. In the Potomac they are found in association at all the localities where either occur and the smaller species is usually the most common as if 8. magnifolia represented the occasional more robust forms of that species. On the other hand the latter has not been detected in the abundant remains of S. variabilis found at Oak Creek, Wyoming, and there is commonly considerable dis- parity in size between the two. There are certain other differences which appear to be constant. These are the thicker, relatively longer leaflets of 8. magnifolia with less numerous and somewhat more ascend- MARYLAND GEOLOGICAL SURVEY 473 ing secondaries which are not connected distad by relatively flat arches. The writer includes under this species the 8. tenuinervis of Fontaine recorded from the localities near Brooke, Virginia, and from Fort Foote, Maryland. The only apparent ground for its erection was a fancied difference in venation based chiefly on a more slender midrib and more remote leaflets, both characters which are seen to be variable and alto- gether unreliable as soon as any number of specimens are compared. The specimens from Deep Bottom, Virginia, which formed the basis for the species Aralia dubia Fontaine (Aralia Fontainet Knowlton) are doubtfully included under this species since they seem to represent a macerated and distorted specimen of the terminal leaflets of a Sapindopsis. There is absolutely no ground for retaining it in Aralia. Occurrence—Patapsco Formation. Near Brooke, near Widewater, Deep Bottom (?), 72-mile post, near 72-mile post, Aquia Creek, White House Bluff, Virginia,” Ft. Foote, Stump Neck, Maryland. Collections.—U. 8. National Museum, Johns Hopkins University. SAPINDOPSIS BREVIFOLIA Fontaine Plate LXXXVII, Figs. 2-5 Sapindopsis brevifolia Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 300, pl. cliii, fig. 4; pl. clv, figs. 1, 7; pl. clxiii, fig. 3. Sapindopsis brevifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 481, 482, 528. Sapindopsis brevifolia Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 644, Description.—Leaves odd-pinnate, the terminal leaflet considerably larger than the lateral leaflets of which but two pairs are known. These are opposite. Leaflets somewhat crowded so that their margins often overlap, with subacute tips, varying in length from 2 cm. to 5 cm. and in width from 0.8 cm. to 1.6 cm., averaging about 3 cm. long by 1.3 cm. wide. Inequilateral toward the base and showing considerable variation in decurrence even among the few specimens known, in some the rachis is conspicuously winged while in others the leaflets are all petioled, the 1Table on p. 586, Mon. xlviii, gives Colchester road as an additional locality, which is not mentioned in the text. 474 SysTEMATIC PALEONTOLOGY whole having the aspect of some member of the Leguminosew. Midribs stout, secondaries ascending, camptodrome, seen with difficulty, since the leaf texture is coriaceous. This is a poorly marked species of infre- quent occurrence at the same localities where the other species of this genus occur and may simply represent a variant of 9. variabtlis. Occurrence.—Patarsco Formation. Fort Foote, Maryland; near Brooke, 72-mile post, Aquia Creek, Virginia. Collections—U. 8. National Museum, Johns Hopkins University. Family CELASTRACEAE Genus CELASTROPHYLLUM Goeppert [Die Tertiarflora auf der Insel Java, 1854, p. 52] The family Celastracee is a most important one for the paleobotanist embracing a large number of forms, many of which are definitely referred to living genera. such as Celastrus, Pterocelastrus, and Euonymus. In a large number of cases, however, it is impossible to exactly locate the fossil leaf within the family so that the genera Celastrinites Sap. and Celastrophyllum Gopp. have been used for a large number of leaf-forms, while the genus Celastrinanthium Conwentz has been proposed for the flowers, which occur in the Baltic amber. The genus Celastrophyllum was proposed by Goeppert in 1854 to include four species from the Tertiary of the island of Java, although a number of authors like Fontaine follow Schimper in crediting the genus to Ettingshausen who wrote considerable about it, including his well-known and beautifully illustrated memoir on the venation of the Celastrinee.* It may be briefly defined as follows: Leaves simple, mostly small, elliptical in outline, with entire or toothed margins; secondaried branch- ing at a wide angle, numerous, parallel, connected by arches near their extremities. In the species with toothed margins short subsidiary veins from these arches enter the marginal teeth. *Denks. k. Akad. Wiss., Wien, vol. xiii, p. 43. MarYLAND GEOLOGICAL SURVEY 475 The most ancient horizon recorded for this genus is that of the Potomac Group, Professors Fontaine and Ward having described no less than thirteen species from strata of that age in Maryland and Virginia. This proves to be altogether too large a number, however, as a critical examination of the material shows that the three forms C. arcinerve Fontaine, C. marylandicum Fontaine, and C. proteoides Fon- taine are not referable to Celastrophyllum at all. C. tenuinerve and C. obovatum of Fontaine are included in that author’s C. latifolium while C. obtusidens Fontaine and C. pulchrum Ward are included in C. acutidens Fontaine. The genus is not present in the older Potomac, i. ¢., the Patuxent or Arundel formations, but is present in considerable force in the Patapsco formation with four species in Maryland and three additional species in Virginia, one of the latter being identical with a form from the New Jersey Raritan. The latter formation has nine recorded species and embracing the largest leaves which have been referred to this genus. The Dakota Group also has several species as has the Cenomanian and Senonian of Greenland and Europe. A large display of these forms is also made in the Paleocene of Europe from which Saporta and Marion have described the well preserved remains of seven species of Celastrophyllwm and four species of the allied Celastrinites. Few species have been described from strata younger than Hocene, the more modern leaves of this type being more readily correlated with the various living genera of this family. The living descendants of the American fossil forms are _ probably to be found among those species which inhabit the American tropics or those which took refuge in the mountains of eastern Asia after the retreat of the Pleistocene -glaciers. CELASTROPHYLLUM DENTICULATUM Fontaine Plate XC, Figs. 1, 2 Celastrophyllum denticulatum Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 306, pl. clxix, fig. 10; pl. clxxii, fig. 7. 476 SysteMATICc PALEONTOLOGY: Description.—Leaves small, 2 to 4 em. in length by 1.25 cm. in breadth, ovate in outline, with an acute apex and a broad, slightly decurrent base. Margin with small, shallow, dentate teeth. Midrib slender. Secondaries numerous, parallel, branching from the midrib at an angle of about 40°, their ultimate disposition not made out. This species is very rare in the Federal Hill collections and is readily distinguished from the other species of this genus by its general outline and by its marginal characters. % Occurrence—Patarsco Formation. Federat Hill (Baltimore), Maryland. Collection.—U. 8S. National Museum. CELASTROPHYLLUM PARVIFOLIUM (Fontaine) Berry Saliciphyllum parvifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 303, pl. clxxii, fig. 5. Saliciphyllum ellipticum Fontaine, 1890, Ibid., p. 303 (pars). Celastrophyllum brookense Fontaine, 1890, Ibid., p. 305, pl. clviii, fig. 8; pl. clix, fig. 7. Celastrophyllum brookense Fontaine, 1906, in Ward, Ibid., vol. xlviii, 1905, p. 505, pl. ex, fig. 10. Description.—Leaves of variable size, 2.5 cm. to 12 cm. (?) in length by 1.3 cm. to 5.5 cm. in greatest width which is about half way between the apex and the base. Outline broadly elliptical, with apex and base somewhat abruptly and about equally acute. Margin entire. Petiole and midrib stout. Secondaries about 5 or 6 pairs, branching from the midrib at a rather wide angle (over 45°) and rather straight in their course, camptodrome. Leaf texture coriaceous. This species which is of somewhat doubtful botanical affinity is based on uncommon and rather fragmentary remains confined to the Patapsco formation. Occurrence.—Patapsco Formation. Near Wellhams, Anne Arundel County, Federal Hill (Baltimore), Maryland; 72-mile post and Hell Hole, Virginia. Collection.—U. S. National Museum. MaryYLAND GEOLOGICAL SURVEY 477 ° CELASTROPHYLLUM LATIFOLIUM Fontaine Plate XC, Figs. 6-9 Celastrophyllum latifolium Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 306, pl. clxxii, figs. 3, 6; pl. clxxili, fig. 13. Celastrophyllum tenuinerve Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 306, pl. clxxii, fig. 2. . Celastrophyllum obovatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 307, pl. elxxii, figs. 9, 10. Celastrophyllum latifolium Fontaine, 1906, in Ward, Mon. U. S. Geol. Sur- vey, vol. xlviii, 1905, p. 559, pl. exvi, fig. 6. Proteephyllum Uhleri Fontaine, 1906, in Ward, 1905, Mon. U. S. Geol. Sur- vey, vol. xlviii, 1905, p. 564, pl. exviii, fig. 5. Celastrophyllum obovatum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 550, 560, pl. cxv, fig. 6; pl. exvii, figs. 2, 3. Description.—Leaves of delicate texture, obovate to nearly orbicular in outline, with a broadly rounded tip and a somewhat decurrent base, length 3 cm. to 6 cm., greatest width 2.2 cm. to 4.5 cm., widest about half way between the base and apex, margin entire. Midrib and secondary venation delicate. Secondaries numerous, approximately parallel, branching from the midrib at a usually acute angle, the lower pairs long and curved upward parallel with the leaf margins, camptodrome. There is considerable minor variation in the venation characters of these leaves and as the delicate secondaries tend to be obliterated in all except the basal part of the leaves where they are more ascending, specimens in this state of preservation appear to have a palmate venation. This species, which is rather common in the collections from Federal Hill, shows considerable variation in size and appearance and is the least satisfactorily determined Celastrophyllum from the Potomac Group suggesting the genus Chondrophylium rather than Celastrophyllum. This variation is really one of the distinguishing characters of the species as here defined. A single specimen has been collected from the Vinegar Hill locality. A single specimen from Federal Hill, slightly shorter and wider than the average with consequently more obtusely branching secondaries, was made the basis for the species Proteephyllum Uhleri Fontaine, although it is not allied with that genus and is clearly a slight variant of the present species. 478 SYSTEMATIC PALEONTOLOGY Occurrence.—Patapsco Formation. Federal Hill (Baltimore), Vinegar Hill, Maryland. Collections.—U. 8. National Museum, Goucher College. CELASTROPHYLLUM ACUTIDENS Fontaine Plate LXXXIX Celastrophyllum acutidens Font., 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 305, pl. clvi, fig. 8. Celastrophyllum obtusidens Font., 1890, Ibdid., 1889, p. 305, pl. elvi, fig. 5. Myrica brookensis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 310, pl. cl, fig. 11; pl. elvi, fig. 10. Celastrophyllum pulchrum Ward, 1899, 19th Ann, Rept. U. S. Geol. Surv., pt. ii, 1899, p. 706, pl. clxxi, figs. 3, 4. Myrica brookensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 518, pl. cviii, fig. 8. Celastrophyllum acutidens Font., 1906, in Ward, Ibid., vol. xlviii, 1905, p. 529, pl. exiii, figs. 7, 8. Description.—Leaves ovate-elliptical in outline, varying considerably in size and relative proportions, ranging from 2.5 cm. to 6 cm. in length and from 1.5 cm. to 4 cm. in width. Margin irregularly toothed, crenate- dentate or shallowly rounded, directed slightly forward and obsolete toward the base of the leaf. Petiole comparatively long and very stout. Midrib also stout, more or less flexuous, diminishing rapidly toward the apex of the leaf. Secondaries generally in four or five alternate pairs, diverging at an angle of about 45° and running with a slight upward curve and somewhat irregularly three-fourths of the distance to the margin where they turn sharply upward to join a lateral fork of the secondary next above, sending off tertiary lateral branches which loop along the margin and from which branches enter the marginal teeth. Characteristic of the type of venation usually ascribed to Celastrophyllum. These leaves are all more or less fragmentary, usually lacking the apex or base, or portions of the margin, as if they had been submerged a considerable time before fossilization. They are also rather contorted and fractured by the settling or creep of the arenaceous clay matrix. This is one of the characteristic species of the Patapsco formation and is very abundant at the Fort Foote locality but has not been found 4 MaryYLanp GEoLogicaL SURVEY 479 elsewhere in Maryland. From Virginia it is recorded in beds of this age at the 72-mile post near Brooke, near Widewater and White House Bluff. The same species also occurs at Evan’s quarry in the Black Hills at a horizon which Prof. Ward places low down in the Dakota Group but which may be more properly included in the Fuson formation They find their counterpart in the-European Cretaceous in the forms described by Saporta from the Albian of Buarcos in Portugal as Myrsinophyllum revisendum. Occurrence—Patapsco Formation. Ft. Foote, Prince George’s County, Maryland ; White House Bluff, near Brooke, Widewater, Chinka- pin Hollow, Virginia. Collections —U. S. National Museum, Johns Hopkins University. CELASTROPHYLLUM Britronianum Hollick Plate XC, Fig. 3 Celastrophyllum Brittonianum Hollick, 1896, in Newberry, Mon. U. S. Geol. Survey, vol. xxvi, 1895, p. 105, pl. xlii, figs. 37, 38, 46, 47. Celastrophyllum Brittonianum Ward, 1896, 15th Ann, Rept. U. S. Geol. Sur- vey, 1895, pp. 349, 358, 377, 378, 379. Celastrophyllum Brittonianum Ward, 1906, in Fontaine, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 493, pl. evii, fig. 7. Description —Leaves small, 4 cm. to 5 cm. in length by 1.2 em. to 2.1 em. in maximum width, which is at or above the middle. Outline ovate- lanceolate, varying toward spatulate in some specimens, with an acute apex and a cuneate or somewhat decurrent base. Margins entire below, denticulate above. Midrib mediumly stout. Secondaries numerous, branching from the midrib at angles of about 45 degrees, very thin but prominent, somewhat irregular, eventually camptodrome. This species was described originally from the Raritan formation of New Jersey, where it is not uncommon, although the exact horizon from which it was collected is not known. It occurs also in the lower part of the Tuscaloosa formation in western Alabama. Its unmistakable presence in the Patapsco formation is of considerable interest since very few forms are known to pass from the Lower into the Upper Cretaceous. While it 1 Saporta, Fl. Foss. Portugal, 1894, p. 186, pl. xxiv, fig. 10. 31 480 SysTEMATIC PALEONTOLOGY resembles Celastrophyllum albedomus Ward the two species are readily distinguishable. Occurrence.—Patapsco Formation. Mt. Vernon, Virginia. Collection —U. 8. National Museum. CELASTROPHYLLUM HunrTert Ward Plate XC, Figs. 5, 10, 11 Celastrophyllum Hunteri Ward, 1896, 15th Ann. Rept. U. S. Geol. Survey, 1895, p. 358, pl. iv, fig. 9. Celastrophyllum Hunteri Fontaine, 1906, in Ward, Mon. U. 8. Geol. Survey, vol. xlviii, 1905, p. 494, pl. cviii, fig. 6. Celastrophyllum (?) saliciforme Ward, 1906, in Fontaine, in Ward, Mon. U. S. Geol. Survey, vol. xviii, 1905, p. 494, pl. eviii, fig. 7. Description.—Leaves linear-lanceolate in outline, Y cm. to 10 cm. in length by 0.8 cm. to 2.0 cm. in maximum width, which is in the middle part of the leaf. Apex and base about equally pointed. Margin finely and sharply dentate. Midrib mediumly stout becoming thin distad, curved. Secondaries numerous, thin, branching from the midrib at angles of about 45 degrees, more or less forked, eventually camptodrome (not craspedodrome as stated by Professor Ward). : This species is somewhat variable in its relative proportions, the most slender specimen found having been the basis for a distinct specific name. It is similar to Celastrophyllum albedomus Ward, differing chiefly in its much greater elongation. The broader forms suggest Celastrophyllum angustifoliwm Newberry of the Raritan formation. Occurrence.—Patarsco Formation. White House Bluff, Mt. Vernon, Virginia. Collection.—U. 8. National Museum. CELASTROPHYLLUM ALBa&DOMUS Ward Plate XC, Fig. 4 Celastrophyllum albedomus Ward, 1906, in Fontaine, Mon. U. S. Geol. Sur- vey, vol. xlviii, 1905, p. 489 (footnote), pl. cviii, fig. 3. Description.—“ Leaf ovate-lanceolate, rounded at the base and apex, unequal-sided, crenate-toothed, 4 cm. long exclusive of the petiole; which is wanting, 16 mm. wide at the middle; midrib strong and straight, MaRrRYLAND GEOLOGICAL SURVEY 481 secondary nerves camptodrome, delicate, curving forward, forking and anastomosing midway between the midrib and the margin, the branches forming festoons along the margins.”—-Ward, 1906. This species shows some points of resemblance to Celastrophyllum acutidens Fontaine, which is, however, a coarser and more ovate leaf with much larger and more irregular teeth. It also is much like Celas- trophyllum Hunterit Ward, a relatively narrow and more elongated leaf. It is very similar to Celastrophyllum Brittonianum Hollick, differing in being widest below instead of above the middle, in having more prominent marginal teeth which are crenate instead of denticulate, and in the less numerous, more ascending, and earlier forked secondaries. Like the latter species it survives into the Upper Cretaceous Tuscaloosa formation of Western Alabama. Occurrence—Patapsco Formation. White House Bluff, Virginia. Collection —U. S. National Museum. Order RHAMNALES Family VITACEAE Genus CISSITES Heer [Phyll. Crét. d. Nebraska, 1866, p. 19] This genus was instituted by Heer in 1866 for the species Cissttes insignis from the Dakota Group, a tri-lobate, tri-veined leaf with sublo- bate lobes, which presented various points of affinity with the genus Cissus of Linné. Subsequent authors included a variety of leaves in this genus some of which are more or less suggestive of Sassafras, Platanus, ete. The genus makes its appearance in the Patapsco formation of Mary- land and in the Albian of Portugal and is largely developed in later Cretaceous deposits, Lesquereux enumerating no less than seventeen species from the Dakota Group of the West, one of which succeeded in migrating as far as the southern part of South America according to Kurtz. Cissites is much less prominent in the Raritan formation. It 1 Kurtz, Revista Mus. La Plata, vol. x, 1902, p. 54. 482 SysteMATIC PALEONTOLOGY is present in the Cenomanian of Europe and Greenland but is replaced after the Eocene by somewhat similar forms referred to modern allied genera such as Cissus, Vitis, etc. CISSITES PARVIFOLIUS (Fontaine) Berry Plates XCI, XCII Vitiphyllum parvifolium Fontaine, 1890, Mon. U. 8S: Geol. Surv., vol. xv, 1889, p. 309, pl. clxxii, figs. 11, 12. Vitiphyllum multifidum Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 309, pl. clxxiii, figs. 1-9. Cissites obstusilobus Saporta, 1894, Fl. Foss. Port., 1894, p. 190, pl. xxxiv, figs. 12, 18 (non Lesquereux, 1892). Vitiphyllum multifidum Ward, 1896, 16th Ann. Rept. U. S. Geol. Surv., pt. i, p. 539, pl. evii, figs. 2-5. y Vitiphyllum parvifolium Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 558. Vitiphyllum multifidwm Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 553, 565, pl. cxix, figs. 2-5. Description.—Leaves comparatively small but somewhat variable in size, the largest specimens indicating leaves about 6 cm. long by 7 cm. wide. Outline somewhat variable, in general orbicular with base varying from truncate or slightly decurrent to deeply cordate. Divided by deep narrow sinuses into three main lobes and these in turn subdivided into subordinate lobes, all terminating in shallow lobes or broadly rounded crenations. Petioles stout sending off three or more rather straight primaries from their tips, the central and main laterals being the stout- est, the presence of additional primaries being occasioned by the degree of subdivision of the lateral leaf lobes. Secondaries branching from the primaries at an acute angle and running to ‘the tips of the subordinate lobes giving off acutely branched tertiaries which run to the tips of the lobules or teeth. This is the most common form at Federal Hill, several hundred speci- mens, often exceedingly well preserved, being contained in the various collections which have been made. Prof. Fontaine established a new genus for its reception which he called Vitiphyllum although he recog- nized its resemblance to Cissus. There is really no ground for the main- tenance of such a separate genus since the leaves are obviously allied to MARYLAND GEOLOGICAL SURVEY 483 various species generally referred to Cissites, in fact this Potomac species was described as a new species in that genus by Saporta in his description of the fossil plants of Portugal, although the name he used had already been used two years earlier by Lesquereux for a different species. That it is identical with the Potomac plant may be seen by a comparison of one of Saporta’s figures reproduced on pl. xci with the figures of the Federal Hill plant on the same plate. Prof. Fontaine differentiated two species from Federal Hill, the more common multifidum and the very small and rather rare parvifolium, the latter being simply small leaves of the former. The same author described a third species from Potomac Run, Va. (Vitiphyllum. crasst- folium loc. cit., 1889, p. 308, pl. cl. figs. 9, 10), based on what he took to be the middle lobe of a leaf of this. species but which is so incomplete as to be altogether worthless as evidence of the existence of this type in Virginia in beds older than the Patapsco formation. Leaves of the same general plan as Cissites parvifolius are present in succeeding formations where they attain a considerably larger size, thus some of the Raritan forms which Newberry referred to Cissites formosus Heer are very sug- gestive of the Federal Hill plant. A closely allied species called by Velenovsky Cissus vitifolia has also been described from the Cenomanian of Bohemia. Occurrence.—Patapsco Formation. Federal Hill (Baltimore), very common, near Wellhams (?), Vinegar Hill (?), Maryland. Collections——U. 8. National Museum, Johns Hopkins University, Goucher College. Order THYMELEALES . Family LAURACEAE Genus SASSAFRAS Nees and Eberm [Handb. Med. Pharm. Bot., Bd. ii, 1831, p. 418] This genus is characterized as follows by Schimper*: “Folia plus minus ovato-orbiculata, brevissime acuminata, vel triloba, triplinervia, 1Schimp., Pal. Végét., t. ii, 1872, p. 834. 484 SYSTEMATIC PALEONTOLOGY nervis lateralibus suprabasilaribus haud exacte oppositis, subangulo acuto orientibus, ultra medium folium productis, extus ramosis, ramis campto- dromis ; nervis secundariis longe a primariis lateralibus remotis, subangulo aperto emissis, parum numerosis, Camptodromis, nervis tertiariis e nervo mediano et e latere anteriore nervorum lateralium subangulo recto emissis, arcuato-transversis. Bacca pedicello apice incrassato carnosoque imposita, basi perianthii sexpartiti laciniis cincta.” Like all genera which are monotypic in the existing flora Sassafras has a most interesting geological history. The most ancient forms are the following three species of late Lower Cretaceous age from the Mary- land-Virginia area and a fourth species described by Saporta* from the Albian of Portugal. The Upper Cretaceous shows an extensive develop- ment of Sassafras-like forms in Europe, Greenland, and America; the Dakota Group in particular having a large number of species. Although reduced in variety of forms the genus remains cosmopolitan throughout the Tertiary, Sassafras Ferretianwm Massal. which is common in the late Pliocene in France and Italy being almost indistinguishable from the single modern species which is confined to eastern North America. SASSAFRAS BILOBATUM Fontaine Plate XCIII, Fig. 1 Sassafras bilobatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 290, pl. elvi, fig. 12; pl. elxiv, fig. 4. Sassafras bilobatum Berry, 1902, Bot. Gaz., vol. xxxiv, p. 435. ? Sassafras bilobatum Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 506, pl. exi, fig. 5. ; Description.—“ Leaf-substance moderately thick; leaf rather large, elliptical-shaped at base, cut into a rather long lateral lobe, ovate in shape, which is turned away from the midrib, having the opposite side of the leaf gently rounded off; terminal lobe much larger, ovate in shape; midnerve strong, sending off on the right-hand side from near the base and into the lateral lobe a strong nerve, and on the left-hand side from a little higher a smaller one, which curves upward, following the margin * Saporta, Fl. Foss. Portugal, 1894, p. 182, pl. xxxi, fig. 7. MaryLanp GroLogicaL SuRVEY 485 of the leaf for some distance; the midnerve above the base at different points sends off minor nerves, which curve upwards and fork; ultimate nervation not seen.”—TFontaine, 1890. While the outline of this leaf does not exactly conform to any modern bilobed Sassafras leaf known to the writer, it is nearer the latter than it is to any other leaf. The right-angled sinus with straight sides and running to a point is also a feature not seen in the modern leaf. In the latter, when the sinus runs to a point it is narrow and deep; and when it forms a right angle it is curved and the resulting lobe is generally obtuse and but slightly produced. We have characters which ally this ancient leaf to Sassafras in the decurrent base ; the subopposite primaries, as they usually are in the bilobed leaves of the existing Sassafras; the position of the secondaries; and especially in the secondary running to the sinus, a feature we would hardly expect to find in so primitive a leaf. We would consider the bilobed leaf as a more ancient type than the trilobed form, and removed from the ancestral simple leaf by a series beginning with leaves with but a slight depression marking the position of the future sinus, and a slightly produced obtuse lobe, through forms partially paralleled in the modern leaf, in which these features were more and more emphasized. Just why the leaf became lobed is largely conjectural. The primaries form a more acute angle with the midrib than do the secondaries, especially in the simple leaves; they are the first and largest arteries branching from the midrib; in the growing leaf they are carried upward, while new laterals are added toward the tip of the blade. It may be that the diagonal position of the leaves in the bud causes pressure at that particular lateral part near the tip of the primary, causing more or less atrophy of that part of the blade. This tendency once inaugurated the rest is simple, for those portions of the leaf at the tips of the primaries would have nearly all their leaf-forming energy expended in increasing the length of the lobes; possibly especially good environment was a factor in the original location, as witness the great development of the lateral portions of the leaf blade in the five- lobed forms occurring in rich soil. The Potomac species under discus- sion bears some resemblance to certain species referred to Sterculia, as 486 SysteMAtTic PALEONTOLOGY well as to the asymmetrical terminal leaflets of some compound leaves, but we are probably justified in considering it a true Sassafras—the first that can be identified as such with any degree of certainty. As pointed out by Fontaine in the fragment of this leaf figured (by him), the opposite primary is considerably stouter than its fellow which runs to the lobe which is preserved, lending color to the supposition that this species was also trilobed. This species is rare and with the exception of the material from near Brooke, Virginia, it has not been recorded except for a single extremely doubtful fragment reported from the synchronous beds along the Potomac River. Occurrence.—Patapsco Formation. Near Brooke and Hell Hole (?), Virginia, ° Collection.—U. 8. National Museum. SASSAFRAS PARVIFOLIUM Fontaine Plate XCIII, Fig. 2; Plate XCIV, Fig. 2 Sassafras parvifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 289, pl. exxxix, fig. 7. Sassafras cretaceum var. heterolobum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 289, pl. clii, fig. 5; pl. clix, fig. 8; pl. clxiv, fig. 5. Sassafras parvifolium Berry, 1902, Bot. Gaz., vol. xxxiv, p. 434. Sassafras cretacewm var. heterolobum Berry, 1902, Bot. Gaz., vol. xxxiv, p. 435. Description.—Leaves somewhat variable in shape, comparatively small in size, elliptical in general outline, trilobate; the lobes rather short and obtusely pointed or broadly rounded, separated by usually shallow more or less rounded sinuses which do not extend more than half the distance to the base. Length 3 cm. to 9 cm. Width across the lobes 3.25 cm. to 8 cm. Base cuneate, decurrent. Midrib stout. Lateral primaries subopposite, supra-basilar. Secondaries more or less remote, ascending, camptodrome, This is a rather rare but well-marked species very suggestive of, and possibly ancestral to, the Upper Cretaceous Sassafras cretaceum New- berry, as a variety of which Fontaine described one of the Virginia MARYLAND GEOLOGICAL SURVEY 487 specimens. As pointed out by the writer in 1902, the Federal Hill material is simply a small form of the same species. This late Lower Cretaceous species may be duplicated by many of the leaves of the still existing species of Sassafras. It is also closely com- parable with a number of other described fossil species, as for example, some of the forms which have been referred to Aralia grenlandica Heer in which subordinate lateral primaries are not developed and the lobes are full and rounded and not straight margined (cf. Heer, Fl. Foss. Arct., Band vi, Abth. ii, pl. xxxviii, fig. 3). The present species is also extremely close to Sassafras arctica described by Heer* from the Atane beds of Greenland as well as to what Ward * identifies as Sassafras mudgiu from the supposed Dakota sandstone of the Black Hills region and from the Cheyenne sandstone of southern Kansas. Occurrence.—Patarsco Formation. Federal Hill (Baltimore), Stump Neck, Maryland ; near Brooke, Virginia. Collections ——U. 8. National Museum, Johns Hopkins University. SASSAFRAS POTOMACENSIS sp. nov. Plate XCIV, Fig. 1 Description.—Leaves.of relatively small size, palmately trilobate. 9 em. in length by 7 cm. in width from tip to tip of the lateral lobes. Sinuses mediumly open, rounded, not extending more than half way to the base. Lobes narrowly conical, pointed. Base cuneate. Primaries three, diverging from the extreme base of the leaf or just above it. Secondaries mostly concealed, a single one can be made out on the right running from the midrib to the sinus in a manner quite characteristic of the existing Sassafras. Texture thin but coriaceous. This species is based upon rather poor material from several localities of Patapsco age. It is clearly different from any described species and while not positively determinable as a species of Sassafras, it agrees in its general facies with the various species commonly referred to this 1 Heer, Fl. Foss. Arct., Band iii, Abth. ii, 1874, p. 109, pl. xxxi, figs. 3a, b. 2 Ward, 19th Ann. Rept. U. S. Geol. Surv., pt. ii, 1899, p. 705, pl. clxx, figs. 4, 5; pl. clxxi, fig. 1. 488 Systematic PaLEONTOLOGY * genus from the Upper Cretaceous, and it may also be matched by some of the variant leaves of the existing Sassafras. It is rather smaller but otherwise very close to Sassafras acutilobum Lesq., especially the forms from the Raritan formation which Newberry’ identified as this species. It may also be compared with Sassafras protophyllum, a somewhat smaller but otherwise_very similar form described by Saporta from the Albian of Portugal. Occurrence.—Patapsco Formation. Widewater, Dumfries Landing, Virginia. Collection.—Johns Hopkins University Order UMBELLALES Genus ARALIAEPHYLLUM Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 316] This, genus is defined as follows by its describer: “ Leaves more or less fan-shaped, divided more or less deeply into three principal lobes, the middle or terminal one subrhombic or elliptical in outline, rapidly narrowed to an acute tip, and separated from the lateral lobes by broad sinuses rounded at the bottom; the lateral lobes divided into two minor lobes, one being larger than the other; the larger one ovate, sometimes inequilateral, and turned upwards; the outer or small one is ovate, and turned outwards; the primary nerves three, radiately diverging from the same or nearly the same point at the base of the leaf, going to the summit of each primary lobe; from the two lateral primaries a strong branch goes off a short distance above the base on the lower side and extends to the summit of the outer smaller lobes; all the primaries are strong, and send off on each side branches which curve up and anastomose; ultimate reticulation not seen.” While the specific differentiation within the genus is somewhat different in the present treatment, the foregoing diagnosis will answer in the *Newberry, Mon. U. S. Geol. Surv., vol. xxvi, 1896, p. 87, pl. xxv, figs. 1-10; pl. xxvi, figs. 2-6. ‘ MARYLAND GEOLOGICAL SURVEY 489 present connection. One feature should be emphasized, however, and that is the variability in lobing which these leaves show. They are primarily palmately trilobate in character, but show a considerable range in varia- bility in the development of subordinate lobes on any or all of the princi- pal lobes. The point of insertion of the secondaries and the character of the apices, whether obtusely rounded or acutely pointed, are also very variable characters. Their coriaceous texture should also be referred to. This variability in lobation in Araliephyllum finds an analogy in the like variation among the leaves of the modern Sassafras as pointed out by the writer in 1902.1 Sassafras is predominantly entire or trilobate but individual leaves can be found showing every stage of incipient loba- tion up to leaves with five or even six lobes which are strikingly similar to the leaves of Araliephyllum (compare the plates of the latter with /oc. cit. figs. 2-4). ; In the original treatment of the genus four species were recognized. These have here been reduced to two species with which have been united certain forms described by Fontaine as Aceriphyllum, Platanophyllum, and Hederephyllum. The material is all rather fragmentary and is strictly confined to the Patapsco formation. With regard to the botanical affinity of these forms, like so many of the Lower Cretaceous dicotyledones, little can be said of a decisive nature. They are comprehensive types and unite the foliar characters of leaves which in the Upper Cretaceous are referred to Aralia, Sassafras, Platanus, and Cissites. As the genus Aralia is used by paleobotanists it would naturally include the following forms, although there is a distinct advantage in the present case in keeping them separate as con- stituting the genus Araliephyllum which indicates without undue defi- niteness their supposed affinity with the modern Araliacez. One of the species, Araliephyllum crassimerve (Fontaine), shows considerable resemblance to the Raritan form Aralia Newberryi Berry and was doubtless ancestral to it. 1 Berry, Bot. Gazette, vol. xxxiv, 1902, pp. 426-450. « 490 SysTreMATIC PALEONTOLOGY The genus Araliephyllum of Fontaine must not be confused with Araliophyllum, a name proposed by Debey in manuscript for certain Upper Cretaceous leaves from Aachen in Rhenish Prussia and published by Schimper in 1874." ARALIHPHYLLUM ORASSINERVE (Fontaine) Berry Plate XCV, Figs. 1-3 Platanophyllum crassinerve Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 316, pl. clviii, fig. 5. Araliephyllum obtusilobum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 317, pl. clxiii, figs. 1, 4; pl. elxiv, fig. 3. Araliephyllum acutilobum Fontaine, 1890, Mon. U. 8S. Geol. Surv., vol. xv, 1889, p. 318, pl. elxiii, fig. 2. Description.—Leaves of medium or small size ranging from 6 cm. to 10 cm. in length by from 5 cm. to 10.5 cm. in greatest width, orbicular in general outline. Primarily palmately trilobate, usually with a subordinate lobe on the outside of each lateral lobé, occasionally two such lobes are developed and sometimes the apical lobe is also sub- lobate. Texture coriaceous. Lobes usually broadly ovate in outline with generally rounded (occasionally acute) tips. Sinuses rounded, the main ones rather narrow and extending about half way to the base of the leaf. Subordinate sinuses shallower and more open. Petiole, pre- served for a length of 3 cm. in one specimen, stout, as is also the midrib. Lateral primaries two in number (one on each side), coarse in calibre, branching from the midrib at or near its base at angles of about 30° and running to the tips of the main lateral lobes. On the outside a short distance above their point of insertion they give off rather stout laterals which run to the tips of the principal subordinate lateral lobes. The true secondaries are numerous in all of the lobes; they are com- paratively fine in character and camptodrome. The base of the leaf is cuneate in outline and slightly decurrent on the petiole. In some of the broader leaves the base approaches a truncate outline. As constituting this species the writer has combined Platanophyllum crassinerve, Araliephyllum obtusilobum and Araliephyllum acutilobum * Schimper, Pal. Végét., t. iii, 1874, p. 38. MARYLAND GEOLOGICAL SURVEY 491 of Fontaine, the first and the last based on very sparse material of a fragmentary character which as nearly as it admits of comparison is identical with the type material of the second, in fact Professor Fontaine states that the last two may be identical, a point upon which there can be but little doubt. The remains of these leaves are fairly common at various outcrops of Patapsco age near both banks of the Potomac River but have not been found either to the northward in Maryland or to the southward in Virginia. They undoubtedly represent the ancestral form of Aralia Newberry Berry, a common Upper Cretaceous species which extends from the Raritan through the Magothy formation, and they may be compared more particularly with various forms of this species figured by the writer * from Cliffwood Bluff, New Jersey. The present species does not differ greatly from the next, such differences as are observable being discussed under the latter. Occurrence—Pararsco Formation. Deep Bottom, near Brooke, Virginia; near Glymont, Stump Neck, Maryland. Collections.—U. 8. National Museum, Maryland Academy of Science. ARALLHPHYLLUM MAGNIFOLIUM Fontaine Plate XCVI, Figs. 1-5 Araliephyllum magnifolium Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 318, pl. clix, figs. 9, 10. : Araliephyllum aceroides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 319, pl. clvi, fig. 11; pl. elxii, fig. 2. Aceriphyllum aralioides Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 321, pl. elxiii, fig. 8. Hederephyllum angulatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 324, pl. clxii, fig. 1. Description.—Leaves usually of large size, ovate to orbicular in general outline, ranging from 8 cm. to 17 cm. in length by from 8 cm. to 18 cm. in greatest width, usually longer than wide. Palmately trilobate with subordinate lobes developed exactly as in the preceding species, but to a less degree and frequently not at all. Lobes broadly ovate in 1 Berry, Bull. N. Y. Bot. Garden, vol. iii, 1908, p. 93, pl. xliv. 492 SYSTEMATIC PALEONTOLOGY outline and acutely (but not narrowly) pointed. Sinuses narrow and rounded, the main ones extending half way to the base or somewhat less, the subordinate ones extremely shallow. Texture coriaceous. Petiole stout, as is the usually curved midrib. Lateral primaries two in number, stout, basal or subbasal, sending off a stout branch on the outside which is camptodrome in cases where the lateral lobe is entire and running to the apex of the subordinate lobe when the latter is present. True secondaries numerous, not coarse, camptodrome. Base of the leaf broadly cuneate or truncate, slightly decurrent. This species differs from the preceding in its uniformly larger size and consequent coarseness of texture and venation; in its usually more elongate form and less sublobation; in its truncate base and broader, more acute lobes. As the synonymy shows, the writer has united Araliephyllum magni- folium and Araliephyllum aceroides of Fontaine which show absolutely no distinctive characters except that the material is in the one case more fragmentery than in the other. With these it has been found necessary to unite the genus Accriphyllum of Fontaine founded upon a single specimen (as nearly as can be made out from the U. 8. National Museum collection) which is identical with the remains just cited. Professor Fontaine compares it with Araliephyllum and gives as its only diagnostic character the lack of subordinate lobes, which as we have seen is of minor importance in the present genus. Finally Hederephyllum angulatum Fontaine is also found to be identical with the foregoing. It was based upon a single incomplete specimen, the only one ever discovered, and was compared by its original describer with Araliephyllum, with which it undoubtedly naturally belongs. The present species is less common than the preceding and, like it, is thus far restricted to the vicinity of the Potomac River, occurring in beds of Patapsco age in both Virginia and Maryland. Because of its large size it is usually found in a fragmentary condition. Occurrence.—Patapsco Formation. Near Brooke, 72-mile post, Virginia; Stump Neck, Charles County, Maryland. Collection._-U. 8. National Museum. MaryYLaNnp GEoLogIcoaL SURVEY 493 INCERTAE SEDIS Genus HEDERAEPHYLLUM Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 323] This genus received the following brief diagnosis by its describer: “ Leaves of rather small size, rotundate in form, with nerves radiating from the base of* the leaf, the middle one being the strongest; petioles long and moderately strong; leaf substance thick.” While the foregoing would apply to a score of genera of dicotyledonous leaves it is difficult to frame a proper diagnosis for such fragmentary remains which are described in more detail under the single species. A second species was described by Fontaine which proved upon careful comparison to be referable to Araliephyllum. The remains constitute an unimportant element in the flora of the Patapsco formation and show no especial affinity with the modern species of Hedera, the supposed resemblance to which was the occasion for the name given to them. HEDERZPHYLLUM DENTATUM (Fontaine) Berry Proteephyllum dentatum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 286, pl. clvi, fig. 7; pl. clxxii, figs. 1, 4; pl. clxxiii, figs. 12, 14. Hederephyllum crenulatum Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 324, pl. elxii, fig. 3. Proteephyllum dentatum Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 563, pl. cxviii, figs. 3, 4. Description.—Leaves ovate to orbicular in general outline, 5 cm. to 6 cm. in length by 2 cm. to 6 cm. in greatest width. Apex obtusely rounded. Base usually subcordate. Margin varying from crenulate to dentate. Petiole stout. Midrib slender and but slightly differentiated. Primaries slender, four to six in number, diverging at narrow angles from the apex of the petiole, somewhat flexuous and sooner or later anastomosing by their dichotomous forking to produce large elongate subrhombic meshes.. Secondaries few, ultimately conpedostnens. Texture coriaceous. This species in the condition of numerous imperfect and illy-defined fragments is common in the Federal Hill beds and occurs sparingly 494 SYSTEMATIC PALEONTOLOGY near Brooke, Virginia. As here recognized it embraces certain apparently identical forms which were the basis for Proteephyllum dentatum Fontaine, but which have no observable characters in common with the species of that genus. They may be compared with various supposed, but not true, species of Protorhipis: Occurrence.—Pataprsco Formation. Federal Hill (Baltimore), Maryland; near Brooke, Virginia. Collection.—U. S. National Museum. Genus PROTEAEPHYLLUM Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 281] This genus was established by Fontaine in 1890 for certain remains of supposed primitive angiosperms and eight species, so-called, were included in it. Since that date the same author has described several additional species, also of nominal value. The original discussion which is reproduced in the present connection for the sake of completeness is as follows: “T group under this head a number of leaves with a very archaic type of nervation that occur in the Potomac flora. In their nervation, and in many cases in the form of the leaves, they bear a greater resem- blance to species of Protea than any other plants. The main points that characterize them are the absence of any pronounced difference in the size of the primary nerves, the great slenderness of these, the lax and irregular reticulation formed, and the uniformly strong ultimate nerves, which gives a reticulation that reminds one of ferns. Indeed, I was for some time in doubt whether some of these leaves were really angio- sperms and not ferns. There are two types of these leaves, that differ only in the presence or the absence of a distinct midrib; when the midrib is present the leaves assume an elliptical form; when it is absent, they tend to take an orbicular shape. We might perhaps divide the genus into two subgenera according to this distinction, giving one the name rotundatum and the other the appellation elongatum. “The genus may be described as follows: Leaves orbicular or elongate in form; in the case of the former, no midrib present; in the case of MARYLAND GEOLOGICAL SURVEY 495 the latter, a thick, vaguely defined, and apparently somewhat succulent midrib exists; petioles proportionally very thick and apparently succu- lent; nervation of the primary order very slender, and with little or no difference in the strength of the primary nerves; reticulation of all orders lax, irregular in shape, and varying in the size of the meshes; ultimate nerves strong, all of equal strength and fern-like. These leaves form an important portion of the angiosperms that occur with a pre- dominant flora of Jurassic type, as at Fredericksburg, and they give a very ancient look to the angiospermous element of the flora.” Any discussion of Proteephyllum must take into account the history of the genus ‘Protorhipis since the American species have been referred to that genus by Ward and since similar leaves from foreign localities have also been unhesitatingly so identified. The genus Protorhipis was founded by Andrae in 1853 for certain large Liassic forms from Banat in Hungary. Subsequently Zigno’ described a species from the Oolite of Italy in 1865, Nathorst two additional species from the Rhetic of Sweden* in 1878, Heer in 1880 a species from the Oolite of Siberia," and in 1882 a species from the Barremian of Kome,® Greenland. Saporta in 1894 described another Barremian species ° this time coming from Portugal and another poorly characterized species from the Rhetic of Sweden.’ Seward records * a species from the Wealden of Bernissart, Belgium, and recently Knowl- .ton has described still another species from the Kootanie of Montana.” Intimately involved with the foregoing is the genus Hausmannia of 1 Andrae, Foss. fi. Siebenburgens u. d. Banates, Abh. k. k. geol. Reichs,, Bd. ii, Ab. ili, 1853, p. 35, pl. villi, fig. 1. 2 Zigno, Fl, Foss. Oolith., i, 1865, p. 180, pl..ix, figs. 2, 2a. 3 Nathorst, Fl. v. Bjuf., i, 1878, p. 42; ii, 1879, p. 57, pl. xi, figs. 2, 4. *Heer, Fl. Foss. Arct., Bd. vi, Ab. i, 1880, p. 8, pl. i, fig. 4a. 5 Heer, Ibid., Ab. ii, 1880, p. 10, pl. iii, fig. 11. ®‘ Saporta, Fl. Foss. Portugal, 1894, p. 144, pl. xxii, figs. 9-11; pl. xxvi, figs. 17, 18; pl. xxvii, figs. 1-5. ‘ 7 Saporta, Ibid., p. 143, pl. xxii, figs. 14, 14a. ® Seward, Mém. Mus. d’Hist. Nat. Belg., tome i, 1900, p. 18, pl. iii, fig. 34. ®Knowlton, Smith. Mise. Coll. (Quart.), vol. 1, pt. i, 1907, p. 114, pl. xii, figs. 3, 4. 32 496 SYSTEMATIC PALEONTOLOGY ‘Dunker* based in the first instance on German Wealden material. A number of species of Hausmannia have been subsequently described including a number of Bornholm specimens which are exactly similar to the type of Protorhipis but which Bartholin named Hausmannia forchhammeri. In reviewing this work Zeiller describes* and figures additional material from the type locality for Protorhipis in Banat, Hungary, and shows that the type of the genus was polymorphous and closely related to ‘the living genus Dipteris. This view is adopted by Moller in 1902 in his revision of the Bornholm flora,” and by Richter, who has still more recently elaborately gone over the whole ground anew. This being the case Hausmannia has priority, having been published seven years before Protorhipis, although both Seward and Knowlton favor the retention of the latter as a purely form-genus. Regarding the systematic position of Protorhipis, it was originally referred to the ferns by Andre who compared his species with the exisiting genus Platyceriwm. Other students compared these forms with the modern genus Dipteris and both Bartholin and Zeiller found fructi- fied material of the latter type. However, Saporta in his review of the subject makes these forms conspicuous members of his Proangiosperms and Ward two years later’ not only follows Saporta’s view but refers the genus bodily to the Dicotyledone, including with it the Potomac forms Proteephyllum reniforme Fontaine, P. orbiculare Fontaine and Populophyllum reniforme Fontaine. These latter are in no wise related to the true forms of Protorhipis (Hausmannia) which are undoubted ferns of the Dipteris type, although they are somewhat similar to Proto- rhipis Choffati Saporta from the Portuguese Barremian and Protorhipis cordata Heer from the Kome beds, neither of which can be compared with Protorhipis (sens stricto). The same may be said of Protorhipis *Dunker, Mon. Norddeutsch. Weald., 1846, p. 12, pl. v, fig. 1. *Bartholin, Nogle i den Bornholmske Juraform forkommende Plante- forsteninger, 1894, pp. 17, 48, pl. xi, figs. 4-6; pl. xii, figs: 1, 2. *Zeiller, Rev. Gén. Botan., t. ix, 1897, p. 51, pl. xxi, figs. 1-5. *MOller, Kgl. Fysiogr. Sallsk. Handl., xiii, 1902, p. 48. * Richter, Beitr. Fl. unteren Kreide Quedlinburgs, Teil i, 1906. * Ward, 16th Ann. Rept. U. S. Geol. Survey, pt. i, 1896, p. 535. MaRryLanp GEOLOGIOAL SURVEY 497 asarifolia Zigno and Protorhipis reniformis Heer which do not appear to be related to the Cretaceous forms just mentioned nor to the true ‘Proto- rhipis but apparently represent detached scales of some Zamiéostrobus or similar object as has been suggested by Nathorst and others. This long discussion terminates at about the point where it started except that it appears clear that Proteephyllum is not a fern of the Protorhigis type. An additional species recently described by Fontaine from the Californian Shasta does not help any since the latter is absolutely undeterminable and uncharacteristic.* There are a number of somewhat similar foliar, stipular, or bracteate objects described by Saporta from the Cretaceous (Albian) of Portugal with which the reniform Potomac species may be compared, such as Braseniopsis venulosa,’ B. villarsioides,’ and Adoxa pretavia,’ but these comparisons are worth little. The only possible view of their botanical Telationship is that they are either angiospermous or filicinean. They may represent aquatic forms of either type or juvenile forms of the fronds of some dimorphic Lower Cretaceous fern. With regard to the ovate forms of Proteephyllum with a midrib these may also be angiospermous or they may be related “to Ficophyllum and Rogersia, which may be early representatives of the Gnetales. They suggest, rather remotely it is true, the two specimens from the Stonesfield slates of England which are described and figured by Seward as simply Phyllites sp.’ Probably it would have been better in the first instance to have described these Potomac forms as Phyllites instead of making them the basis of six different species of angiosperms, but as they are in the literature and the name does not carry any implications of relationship, it has seemed best to retain it, reducing, however, the six nominal species to the two which are actually present in nature. Their true affinity remains 1Font., in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1906, p. 267, pl. lxix, fig. 11. ? Saporta, Fl. Foss. Portugal, 1894, p. 192, pl. xxxiv, figs. 1-4. 3 Ibid., p. 195, pl. xxxv, fig. 9. + Ibid., p. 187, pl. xxxiv, fig. 5. ‘Seward, Jurassic F1., pt. ii, 1904, p. 152, pl. xi, figs. 5, 6, 498 SysTEMATIC PALEONTOLOGY unknown, for while they may be compared with a number of modern plants, they present no characters entitled to any great weight, certainly they do not furnish adequate evidence of their angiospermous nature, although they may well be the remote representatives of this type since there are no grounds, theoretical or otherwisé, to deny the existence of angiosperms at such a relatively late date in the Mesozoic. The genus Proteephyllum of Fontaine must not be confused with Protophyllum Lesquereux (Cret. Fl., 1874, p. 100) or Proteophyllum Velenovsky (Kvétena éeského cenomanu, 1889, p. 18). Saporta has referred a number of Portuguese Lower Cretaceous forms to the latter genus, which is supposed to be related to the existing Proteacem. PROTEHPHYLLUM RENIFORME Fontaine Proteephyllum reniforme Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 282, pl. exxxix, fig. 3; pl. clvi, fig. 4; pl. clx, figs. i, 2 (non Ward, 1895 or 1896, or Fontaine in Ward, 1906). Proteephyllum orbiculare Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 288, pl. exxxix, fig. 4. Phyllites pachyphyllus Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 325, pl. exlix, fig. 2. Description.—Leaves of medium size, reniform to orbicular in out- line, with entire margin, and coriaceous in texture. Length 3 cm. to 6 cm., width 4 cm. to 10 cm. Petiole wide and flat, preserved for a length of 2 cm. in some specimens and at times as much as 5 mm. in width. Primaries numerous, thin, diverging from the top of the petiole, anastomosing irregularly and in a lax manner. No material shedding any new light on this singular form has been collected and its affinity remains unknown. The forms described as the species reniforme, orbiculare, and pachyphyllus are obviously identical and the records from post-Patuxent horizons prove to be based upon decidedly different leaves in no wise related to this species. Occurrence—PatTuxENT Formation. Fredericksburg, near Dutch Gap, Virginia. Collection.—U. 8. National Museum. MARYLAND GEOLOGICAL SURVEY 499 PROTEZPHYLLUM OVATUM Fontaine Proteephylium ovatum Font., 1890, Mon. U. 8. Geol. Survey, vol. xv, 1889, p. 285, pl. exli, fig. 1 (non Fontaine in Ward, 1906, p. 510). Proteephyllum ellipticum Font., 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 285, pl. cxlii, figs. 1, 2. Proteephyllum tenuinerve Font., 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 286, pl. cl, fig. 18; pl. clvi, fig. 2. Description—* Leaves of medium (and large) size, ovate-acute, with the tip bent to one side, abruptly rounded at base, and subcordate; midnerve very thick and apparently somewhat succulent; primary nerves very slender, going off nearly opposite in pairs, basal pair leaving at a very large angle and curving strongly around approximately parallel to margin, those higher up leaving at more and more acute angles, curv- ing gently until near the margin of the leaf, and then bending strongly upwards, gradually approaching the margin, sending off slender branches, which anastomose to form large, lax, and mostly irregular quadrangular primary meshes; ultimate meshes variable in size, distinctly defined, and formed chiefly by the meeting of the nerves under large angles.”— Fontaine, 1890. No new material which can be referred to this protean species has been collected and its botanical affinity remains in doubt. Occurrence—PatuxENT Formation. Fredericksburg, near Dutch Gap, near Potomac Run, Virginia. Collection.—U. 8S. National Museum. Genus ROGERSIA Fontaine [Mon. U. S. Geol. Surv., vol. xv, 1890, p. 287] The present genus was characterized in the following terms by its describer : “Leaves long, narrow, and willow-like, wedge-shaped at base, acute, with a very strong midnerve and very slender primary nerves; these go off very obliquely and diverge very slowly from the midrib, running for a long distance nearly parallel with the margins of the leaves; they 500 SysTEMATIC PALEONTOLOGY anastomose with branches sent off from other nerves of like grade higher up to form very long, irregularly shaped, and lax meshes; ultimate reticulation oblong, subrhombic, of quite uniform dimensions. This genus is named for Prof. W. B. Rogers, who first called attention to the plants of the Potomac formation and studied its geology.”— Fontaine, 1890. What has been said in the case of Proteephyllum and Ficophyllum applies equally well to the present genus, which may be angiospermous, but is more likely referable to the Gnetales, a problem which cannot be solved until fruiting or structural material is discovered. RoGERSIA LONGIFOLIA Fontaine Rogersia longifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 287, pl. exxxix, fig. 6; pl. exliv, fig. 2; pl. cl, fig. 1; pl. clix, figs. 1, 2. Sapindopsis elliptica Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 297, pl. exlvii, fig. 3 (non Font., 1906). Rogersia longifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 588 (non pp. 511, 523, pl. exii, fig. 9). Description.—“ Leaves narrowly elliptical, gradually narrowed to the base and apex, with wedge-shaped base, acute, very long in proportion to width; midrib comparatively very stout; primary nerves very slender, going off very obliquely, proceeding upwards for some distance nearly parallel with the margin, but gradually approaching it; primary nerves sending off very obliquely secondary nerves, which anastomose with their neighbors to form elongate, subrhombic, and irregular meshes, which have their maximum dimensions turned upwards and slightly outwards; primary meshes filled with pretty sharply defined ultimate meshes, polygonal in shape, and varying in the number of sides from four to six.” —Fontaine, 1890. No new facts regarding these peculiar forms have been obtained. Occurrence.—PAtUxENT ForMatiIon. Fredericksburg, near Dutch Gap, Kankeys, Virginia. ARruNpDEL Formation. Arlington (?), Mary- land. Collection —U. 8. National Museum. MARYLAND GEOLOGICAL SURVEY 501 ROGERSIA ANGUSTIFOLIA Fontaine Rogersia angustifolia Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 288, pl. exliii, fig. 2; pl. exlix, figs. 4, 8; pl. cl, figs. 2-7. Saliciphyllum longifolium Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, p. 302, pl. el, fig. 12. Rogersia angustifolia Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 521 (non pp. 491, 510). Description.—* Leaves narrow, small, very elongate-oblong, narrowed gradually to the base and apex, subacute, sometimes curved ensiform ; midnerve proportionally very strong, with a thick petiole; lateral or primary nerves very slender, going off at an acute angle and arching up towards the summit, forming more or less persistent nerves approxi- mately parallel with the margin, and having a flexuous course. They send off very obliquely slender lateral nerves, which anastomose with the adjacent ones, and form irregular, elongate, polygonal meshes, with’ their longer dimensions directed upwards. The latter, by splitting up into ultimate nerves, form an irregular, lax, ultimate network.”— Fontaine, 1890. No new material which can be referred to this species has been collected. Occurrence—PatuxEent Formation. Fredericksburg, Potomac Run, Virginia. ARUNDEL Formation. Langdon (?), District of Columbia; Bay View, Maryland. Collection—U. S. National Museum. RoGERSIA ANGUSTIFOLIA PARVA Fontaine Rogersia angustifolia parva Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, p. 523, pl. cxi, fig. 9. Description.—* At this locality five specimens of a dicotyledon were found that indicate a smaller and narrower leaf than the normal Rogersia angustifolia. In fact, the leaves are so narrow that they sug- gest Cephalotaxopsis magnifolia. The nervation, however, although vaguely shown, is that of a dicotyledon, and the leaf substance is thinner than that of a Cephalotaxopsis. This may be a new genus, but the amount of material is too small and the preservation too imperfect to 502 SysTEMATIC PALEONTOLOGY permit the establishment of its full character. It may provisionally be regarded as a variety of Rogersia angustifolia, which it resembles in all determinable points except size.”—Fontaine, 1906. It seems very probable that this supposed variety of Rogersia angus- tifolia is based upon detached leaves of Cephalotaxopsis, but as the writer has not been able to entirely satisfy himself on this point the variety is retained for the present. Occurrence.—ARUNDEL Formation. Langdon, District of Columbia. Collection—U. 8. National Museum. Genus FICOPHYLLUM Fontaine [Mon. U. S. Geol. Survey, vol. xv, 1890, p. 290] This genus was founded by Fontaine in 1890 for certain netted-veined leaves which are present in considerable abundance in the Patuxent formation at Fredericksburg and less commonly at a few other synchro- nous outcrops in Virginia. The specimens are all fragmentary and the preservation is poor so that it is difficult to arrive at any definite con- clusions regarding their true nature. For the sake of completeness the original discussion is quoted in full: “Leaves elliptical in outline, subacute, gradually narrowed at base, with the lamina of the leaf more or less decurrent along the petiole; midnerve and petiole extremely thick proportionally; lateral or primary nerves proportionally and in most of the forms absolutely slender, extremely irregular in arrangement, forming a lax reticulation of very archaic type. Ultimate reticulation strongly marked and fern-like. “This genus is an important one in the Potomac flora, and has con- tributed a considerable number of individuals to the vegetation of that epoch. It is largely developed in association with Jurassic types of plants, as at Fredericksburg, where it is most abundant, and is almost wanting in the strata where more modern elements abound, as at Brooke, White House, and Baltimore. As illustrating the archaic and peculiar features of these leaves and those of Proteephyllum, I may state that for some time no other leaves but these were found at Fredericksburg, and finding them associated only with plants of Jurassic facies I found MaryLanp GroLogicaL SuRvEY 503 it difficult to give any good characters distinguishing them from ferns. There is a general and strong’ resemblance between these plants and some species of Ficus, and for this reason it seems best to place them in a new genus, indicating by its name the apparent affinity with that genus. It is quite possible that these are ancestral forms of Ficus.” The foregoing diagnosis remains correct except that it should be pointed out that the slenderness of the secondaries is purely relative to the midrib, and not actual, as they are for the most part especially stout as may be seen from Fontaine’s figures of these forms. There is one other venation character which should be mentioned since it is of extreme importance in the writer’s judgment as it gives the only clue to the relationship of these forms, a matter of great interest, since we are dealing with what have long supposed to be the most ancient known angiosperms. This is the internal free ending of the veins within the meshes. This type of venation, while present in various angiosperms as for example in certain species of Ficus, Banksia, Cocculus, etc., according to DeBary, is especially characteristic of netted- veined ferns of the Drynaria type and occurs also in the genus Gnetum among the Gnetales. Whether these features are anatomically accurate and the vascular bundles in contradistinction to the veins actually end in this way cannot be determined, but the relatively coarse ultimate venation does show these features. The writer is inclined to think that both Ficophyllum and the allied genera Proteephyllum and Rogersia are not angiosperms but are related either to ferns of the Drynaria,type or to the Gnetales. In outline they are closer to Gnetum-like forms although Ficophyllum serratum agrees fairly well with the basal leaves of Drynaria. The fossils have been carefully compared with a large amount of recent material and with all of the described remains of fern genera like Clathropteris and Dictyo- phyllum without arriving at any definite conclusions other than the conviction that if the remains of Ficophyllum had happened to come from Rhetic instead of Cretaceous strata they would have been unhesi- tatingly referred to the ferns. 504 SYSTEMATIC PALEONTOLOGY In the absence of more representative material, that already known being very poor, no definite result is possible, although the writer is inclined to consider Ficophyllum as being referable to the Gnetales, which were certainly more abundant in the Mesozoic than has ever been suspected. The fact that true dicotyledonous leaves from the Patapsco formation have been confused with these earlier forms by Fontaine has served to effectually complicate the whole question. As a matter of fact all of the specimens, except some doubtfully determined fragments from the Arundel formation in Maryland, come from the basal Potomac of Virginia, i. ¢., from near the base of the Patuxent formation. The fact that some authors use the ending phyllum for all fossil representa- tives of existing genera should not be understood in the present case as indicating that any relationship with Ficus is implied by the reten- tion of Fontaine’s generic name. In the absence of positive data regard- ing the affinity of these forms Ficophyllum has been allowed to stand since no good could possibly result from an arbitrary change of name. FICcOPHYLLUM SERRATUM Fontaine Ficophyllum serratum Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 294, pl. exlv, fig. 2; pl. exlix, fig. 9 (non Fontaine, 1899). Quercophyllum tenuinerve Fontaine, 1890, Mon: U. S. Geol. Survey, vol. xv, 1889, p. 308, pl. cxlix, figs. 6, 7. ? Quercophyllum tenuinerve Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 521. Description — ‘Leaves of moderate size, strongly serrate-toothed, teeth often irregular in size, sometimes double, acute, and directed for- wards; shape of the leaf not fully disclosed, but apparently elliptical; midnerve proportionately very strong, lateral or primary nerves very slender, not fully disclosed, but apparently forming by the union of the branches of the primary nerves irregular large meshes; ultimate nerva- tion not seen.”—Fontaine, 1890. This species was based upon very rare and indecisive fragments of the apical part of leaves whose botanical affinity is entirely unknown. Those equally rare fragments of the basal part of similarly toothed leaves from the same locality described as a species of Quercophyllum tenuinerve MaryYLanp GEOLOGICAL SuRVEY 505 are clearly identical with the former and both are entirely distinct from the fragments described by Professor Fontaine from the Fuson forma- tion of the Black Hills as Ficophyllum serratum. The species is clearly distinct from any other known Lower Cretaceous forms and while it shows no obvious relationship with the other Potomac species of Fico- phyllum nothing is to be gained by any new proposal of botanical affinity since the latter is entirely speculative. The forms are obviously not related to any known forms of Ficus; in fact their dicotyledonous nature is entirely doubtful and they might equally well be referable to some member of the Monocotyledone, the Filicales, or even some member of the Gnetales among the Gymnosperms. No additional material of this species has ever been discovered and were the name not already in the literature it would be preferable to describe it under the non-com- mital name Phyllites or even leave it altogether undescribed. Occurrence——PatuxEnt Formation. Fredericksburg, Virginia. ARUNDEL Formation. Langdon (?), District of Columbia. Collection—U. 8S. National Museum. FIcoPHYLLUM OBLONGIFOLIUM (Fontaine) Berry Proteephyllum oblongifolium Fontaine, 1890, Mon. U. S. Geol. Survey, vol. Xv, 1889, p. 284, pl. cxxxix, fig. 5; pl. cxl, figs. 1, 2. Proteephyllum sp., Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 284, pl. exxxix, fig. 2. Ficophyllum crassinerve Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 291, pl. cxliv, fig. 3; pl. cxlv, fig. 3; pl. exlvi, fig. 1; pl. exlvii, fig. 4; pl. exlviii, figs. 1, 2, 4; pl. clvii, fig. 4; pl. clxxiii, fig. 10 (non Fontaine in Ward, 1906). Ficophyllum tenuinerve Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 292, pl. cxl, fig. 3; pl. exli, fig. 2; pl. exlv, figs. 1, 4; pl. exlvii, fig. 2; pl. cxlix, figs. 1, 3, 5; pl. clvi, fig. 1 (non Fontaine in Ward, 1906). ; Ficus virginiensis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 295, pl. cxliii, figs. 1, 3; pl. exliv, fig. 1. Ficus Fredericksburgensis Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 295, pl. cxlviii, figs. 3, 5. Sapindopsis cordata Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 296, pl. exlvii, fig. 1. Saliciphyllum ellipticum Fontaine, 1890, Mon. U. 8. Geol. Survey, vol. xv, p. 303 (pars), pl. cxlvi, figs. 2, 4; pl. el, fig. 3; pl. clxiii, fig. 5; pl. elxvi, fig. 2. 506 SYSTEMATIC PALEONTOLOGY Proteephyllum odlongifolium Fontaine, 1906, in Ward, Mon. U. S. Geol. Sur- vey, vol. xIviii, 1905, p. 538. Ficophyllum tenuinerve Fontaine, 1906, in Ward, Mon. U. S. Geol. Survey, vol. xviii, 1905, p. 520 (non pp. 504, 510). Description“ Leaf rather large, spatulate, oblong or oblong-ellip- tical, narrowed very gradually below into the petiole; summit not seen; midnerve stout, and continuing to near the tip of the leaf; secondary nerves very slender, leaving the midrib at a more or less acute angle, and arching around in an irregularly flexuous manner to unite with those of the same order next above, sending off branches obliquely, mainly on the outer side, which pursue a flexuous course parallel to the margin of the leaf, finally dissolving into smaller branches; the lateral nerves anastomose into large, irregular meshes, made up of subordinate meshes, the minor branches of the lateral nerves, which meet under large angles, forming a net-work that is very irregular; leaf-substance moderately thick; the ultimate reticulation strong and fern-like.”—Fontaine, 1890. No new material representing this species has been collected and the types of the various supposed species which represent variously pre- served fragments of it are obviously from the same plant and are too poorly preserved to repay refiguring. No evidence regarding its botanical affinity is available. Occurrence.—PatuxENT Formation. Fredericksburg, Dutch Gap, near Dutch Gap, near Potomac Run, Virginia. ARUNDEL ForMATION. Arlington, Prince George’s County, Maryland (1 doubtfully determined specimen). Langdon, District of Columbia ( 1 doubtfully determined specimen). Collection —U. 8. National Museum. Genus ARISTOLOCHIAEPHYLLUM Fontaine [Mon. U. 8S. Geol. Survey, vol. xv, 1890, p. 322] Leaves thick and of very large size with extremely stout and prominent primary and secondary veins. Tertiaries thin but prominent. This genus of entirely unknown affinity except that it is undoubtedly angiospermous was founded in 1890 by Fontaine for fragments of a MARYLAND GEOLOGIOAL SURVEY 507 large leaf rather common in the Patapsco formation. Subsequently a second species entirely unlike the first and equally obscure was tenta- tively referred to the same genus. ARISTOLOCHIAPHYLLUM CRASSINERVE Fontaine Plate XCVII Aristolochiephyllum crassinerve Fontaine, 1890, Mon. U. S. Geol. Survey, vol. xv, 1889, p. 322, pl. clx, figs. 3-6. Aristolochiephyllum crassinerve Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. xlviii, 1905, pp. 481, 504, 528, pl. cix, fig. 1. Description Shape of leaf not seen; the leaves were apparently large and rather coarse ; leaf-substance thick; petiole and primary. nerves very strong and woody ; subordinate nerves strong and cord-like; primary nerves go off from the midnerve at an angle of about 45°, sweeping around to form bow-shaped curves; they send off branches nearly at right angles, which anastomose to form irregularly shaped, strongly defined meshes filled by an ultimate reticulation which is very distinct and prominent, formed by nerves meeting nearly at right angles.”— Fontaine, 1890. , Fragmentary remains of this exceedingly large leaf are not at all uncommon in the Patapsco formation, but they are so very incomplete that the general form of the leaf is not apparent nor are any speculations regarding its botanical affinity likely to prove profitable. Occurrence.—Patapsco Formation. Fort Foote, Prince George’s County, near Brooke, 72-mile post, and Hell Hole, Virginia. Collection——U. S. National Museum. ARISTOLOCHIL#PHYLLUM (?) CELLULARE Ward Aristolochiephyllum ? celluare Ward, 1906, in Fontaine, Mon. U. S. Geol. Survey, vol. xlviii, 1905, p. 492, pl. eviii, fig. 5. Description-—“ Apparently a large leaf of thick, fleshy texture. It was probably rounded in form. The impressions show on their surface a series of cell-like meshes, separated by narrow, raised, flat borders, which appear to be the nerves of the leaf. The specific name of the 508 SYSTEMATIC PALEONTOLOGY plant is founded on the cell-like character of the spaces between these nerves. The meshes cover the entire surface of the leaves. They are polygons made by the meeting, under large angles, of several sides. ‘The number of the sides varies. They are mostly 5 to 8, but may occasionally be fewer. Their size also varies, some being twice as large as others. Within the meshes and grouped, radiating from a central point, are ridges or depressions, according to the relation of the fossil to the original leaf. Depressions seem to have existed originally in the leaf and these leave elevations in the clay embedding the leaf. The number of these radiating inequalities varies. They are mostly 5 or under. The concavities existing on the leaf seem to be puckers in its thick texture. There is apparently nothing like a differentiation of the nerves into grades, such as primary, secondary, etc. The flat, strong, cord-like margins or sides of the cells form the whole of the nervation. But some of the margins of the cells, corresponding in position and placed in the central line of the leaf, are so located as to seem to be continuous of one another and to form an irregular flexuous midrib. This, however, is accidental, and the margins of the meshes are the only nerves possessed by the leaf. The true position of this peculiar leaf is very problematical. It is placed with doubt in the genus Aristolochizephyllum.”—Fontaine, 1906. . As suggested by Ward there is a superficial resemblance to Kaida- carpum cretacewm Heer. The nature of the present form is conjectural, and it may not represent a leaf at all. It is extremely doubtful if it bears any relation to Aristolochiephyllum crassinerve. It may represent the underside of a thick floating leaf of unknown affinity. Occurrence.—Patapsco ForMATION. Mt. Vernon, Virginia. Collection—U. 8S. National Museum. PLATES PLATE XI. PAGE Restoration of the Sauropod (herbivorous) dinosaur Pleurocelus nanus Marsh from Maryland. 1/16 natural size (original). Known por- tions shaded, remainder from MorosaQuruS.........00cee eevee ee cenee 188 510 LOWER CRETACEOUS, PLATE XI MARYLAND GEOLOGICAL SURVEY. SUR RSia Se DINOSAURIA. PLATE XII. Restoration of a Theropod (carnivorous) dinosaur Ceratosaurus from the Morrison formation of Colorado, an ally of the Arundel form Allosaurus. 1/30 natural size. (After Marsh.) 511 LOWER CRETACEOUS, PLATE XII. MARYLAND GEOLOGICAL SURVEY. SES op, DINOSAURIA, PLATE XIII. Restoration of a Predentate (herbivorous) dinosaur Laosaurus from the Morrison formation of Wyoming, a near ally of the Arundel form Dryo- saurus. 1/10 natural size. (After Marsh.) 612 LOWER CRETACEOUS, PLATE XIII MARYLAND GEOLOGICAL SURVEY. DINOSAURIA. PLATE XIV. Figs. 1-3. ALLOSAURUS MEDIUS Marsh....... 0... c cee cence ne eee eee eee 1. Side view of Tooth. Natural size. Near Muirkirk. (3121 G. C.) 2. Front view same. 3. Proximal phalanx of hind foot. X %. Near Muirkirk. (2521 G. C.) Fig. 4. VERTEBRA OF CREOSAURUS POTENS Lull. X 4%. Washington, D. C. (3049) IM. Gs 1S.) sane saa eaten nerhes dikes ee oe eee ee 186 Figs. 5-8. PLEUROCG@LUS NANUS MarSh.......... 0. cece eee eee eee eee eees 5. Left dentary. x 4%. Near Muirkirk. (5669 U.S. N. M.) 8s, sym- physis; a, edentulous margin. 6. Left maxillary. Outer view. xX %. Near Muirkirk. (5667 U. S. N. M.) 7. Outer, front, inner, and back views of a tooth. Natural size. Near Muirkirk. (5691 U.S. N.M.) (After Marsh.) 8. Outer, front, inner, and back views of another tooth. Natural size. Near Muirkirk. (Unnumbered U. S. N. M.) (After Marsh.) 513 MARYLAND GEOLOGICAL SURVEY LOWER CRETACEOUS, PLATE XIV DINOSAURIA. PLATE XV. PAGE Fig. 1. Toota or Ca@.Lurus qgRracizis Marsh. Natural size. Near Muir- kirk. (3336 G.C.) (After Marsh.)............. ce eee eee e eee 187 Figs. 2-5. PLevuroca:Lus nanus Marsh. (After Marsh.)..............66+ 188 2. Posterior cervical vertebra. >< %. Near Muirkirk. (5678 U. S. N. M.) 2a. Section of same at line a-b. 3a. Supra-occipital, superior view. X< %. Near Muirkirk. (5692 U. S. N. M.) 3b. Same, posterior view. 8c. Same, inferior view. 4. Dorsal vertebra. 1%. Near Muirkirk. (4968 U. S. N. M.) f. Lateral cavity (pleurocele). a. Anterior end. p. Posterior end. n. Neural canal. s. Suture for neural arch. 5. Sacral vertebra. Left lateral and posterior views. 1%. Near Muirkirk. (4946 U.S. N.M.) 1, Facet for rib, other lettering as in Fig. 4. 5I4 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XV. DINOSAURIA. PLATE XVI. Figs. 1-5. PLEUROcaLUS NANUS Marsh.......... 0... cece eee eee eens 188 1. Left alisphenoid, outer view. xX %. Near Muirkirk. (5668 U. S. N. M.) 2. Middle caudal vertebra. \ %. Near Muirkirk. Outer and supe- rior views. (4970 U.S.N.M.) (After Marsh.) 3. Front, side, and rear views of proximal caudal vertebra. X %. Near Muirkirk. (5639 U.S.N.M.) (After Marsh.) 4, Front, side, and rear views of distal caudal vertebra. xX %. Near Muirkirk. (5372 U.S.N.M.) (After Marsh.) 5. Rear, proximal, distal, and side views of humerus. xX %. Near Muirkirk. (2263 U.S.N.M.) (After Marsh.) 515 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XVI. DINOSAURIA, PLATE XVII. PAGE Figs. 1-3. PLeuroca@tus nanus Marsh. (After Marsh.).............-+4- 188 1. Front, proximal, distal, and side views of metacarpal. xX %. Near Muirkirk. (2265 U. S. N. M.) 2. Front, proximal, distal, and outer views of femur. xX %. Near Muirkirk. (2263 U.S. N. M.) 3. Front, proximal, distal, and rear views of tibia and fibula. x %. Near Muirkirk. (5656, 5657 U. S. N. M.) 516 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, FLATE XVII. DINOSAURIA. PLATE XVIII. PAGE Figs. 1, 2. PLeurocastus nanus Marsh. (After Marsh.)................ 188 1. Front, proximal, distal, and side views of metatarsal. x 4%. Near Muirkirk. (2267 U. S. N. M.) 2. Outer, front, proximal, and inner views of ungual phalanx. xX %&%. Near Muirkirk. (2267 U. S. N. M.) Fig. 3. PLEUROC@LUS ALTUS Marsh............ cece eee e eee c ee eee e ee enee 200 Front and side views of tibia and fibula) xX %. Near Miirkirk. (4971 U. S. N. M.) . MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XVIII. 3 DINOSAURIA. PLATE XIX. Figs. 1-4. PLEUROCG@LUS ALTUS Marsh.......... 0c ccc eee cece eee eeeee 200 1. Metatarsal. x 4%. Near Muirkirk. (5687 U. S. N. M.) 2. Middle caudal vertebra, front view. XxX 1%. Near Muirkirk. (5626 U.S. N. M.) 3. Same, side view. 4, Outer and side view of togth. Natural size. Near Muirkirk. (3333 G.C.) (After Marsh.) : Fig. 5. ASTRODON JOHNSTONI Leidy. Outer, side, and inner views of tooth. Natural size. Bladensburg. (798 Yale Mus.) (After Marsh.). 202 Figs. 6, 7. DRYOSAURUS GRANDIS Lull......... 0... cece eee eee eee ences 204 6. Astragalus, front view. xX %. Near Muirkirk. (5652 U. S. N. M.) 7. Metatarsals, front view. xX %. Near Muirkirk. (5684, 5704 U.S. N. M.) 518 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XIX. DINOSAURIA. Figs. 1 1. wo Figs. 5 Hig. 7. PLATE XX. =4, DRBYOSAURUS: GRANDS: Laud Uo ios sacdciscoe scatseccsi sew issawernen's ivevnte's, Sr sbhbaW anebiie 204 Side view of proximal phalanx. X %. Near Muirkirk. (5453 U. S. N. M.) . Front view of same. ; . Phalanx. X %. Near Muirkirk. (2609 G. C.) . Front and side views of ungual phalanx. X %. Near Muirkirk. (U. S. N. M.) , 6. Princonopon crassus Marsh. (After Marsh.)............... 207 . Outer, edge, and inner views of tooth. Natural size. Muirkirk. (2135 U. S. N. M.) . Dorsal and left lateral view of dorsal vertebra. xX %. Near Muir- kirk. (3101 G.C.) GONIOPHOLIS AFFINIS Lull......... 0. cece cece eee ee en eeeee 210 Edge view of tooth. Natural size. Branchville. (8175 W. C. B.) 519 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XX. DINOSAURIA.—CROCODILIA. ‘ PLATE XXI. Figs. 1-3. VIVIPARUS MARYLANDICUS CLANK, caauesocojek Arlington, Maryland. Figs. 4-5. VIVIPARUS ARLINGTONENSIS Clark............... Arlington, Maryland. Fig. 6. BYTHINIA ARUNDELENSIS Clark................0405 Arlington, Maryland. Fig. 7. UNIO PATAPSCOENSIS Clark.............00 cece eee White House Bluff, Virginia. Figs. 8, 9. CYRENA MARYLANDICA Clark................6. Arlington, Maryland. 520 MARYLAND GEOLOGICAL SURVEY, LOWER CRETACEOUS, PLATE XxXI, MOLLUSCA. , Boston. . PLATE XXII. PAGE Figs. 1-9. ScHIZHOPSIS AMERICANA BeIrry........ 00.0 ce cece cence eens 1. Type specimen from Fredericksburg, Virginia, showing frond with attached groups of sporangia (nat. size). 2. Cast of cavity occupied by group of sporangia showing faint trans- verse lines which indicate the compound nature of these objects shown in Fig. 1 (enlarged X 4). 3. A fructification from Fig. 1, showing the continuation of the ped- uncular vein to the apex, indicating that these objects are not large simple sporangia, but compound (enlarged xX 4). 4. Micro-photograph of a spore showing ornamentation and tetrad scar (enlarged X 365). 5-9. Camera lucida drawings of spores in various positions showing ornamentation, tetrad scars and thick walls (enlarged X 380). 621 216 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XxXIl. PTERIDOPHYTA. UGckavee. JJOSTON. PLATE XXIII. PAGE Figs. 1, 2. ACROSTICHOPTERIS LONGIPENNIS Fontaine................... # 223 1. Federal Hill, Maryland (after Fontaine). 2. Hell Hole, Virginia (after Fontaine). Figs. 3, 4. Rurrorpra Gaprrertr (Dunker) Seward.............--....4- 231 3. Fredericksburg, Virginia (after Fontaine). 4. Pinna of same. X 3. Figs. 5, 6. RUFFORDIA ACRODENTATA (Fontaine) Berry................... 230 5. Dutch Gap, Virginia (after Fontaine). 6. Pinna of same. X 2. 622 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XxXill. PTERIDOPHYTA, PLATE XXIV. PAGE Fig. 1. ACROSTICHOPTERIS CYCLOPTEROIDES Fontaine..............-..005- 226 Dutch Gap, Virginia (after Fontaine). Figs. 2, 3. ACROSTICHOPTERIS ADIANTIFOLIA (Fontaine) Berry............ 224 Fredericksburg, Virginia (after Fontaine). Figs. 4, 5. ACROSTICHOPTERIS PARVIFOLIA Fontaine...............0eeeeee 226 Fredericksburg, Virginia (after Fontaine). Fig. 6. ACROSTICHOPTERIS PLURIPARTITA (Fontaine) Berry............... 227 Dutch Gap, Virginia. Fig. 7. ACROSTICHOPTERIS LONGIPENNIS Fontaine.............-..0e sees 223 Aquia Creek Cut, Virginia. 523 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XXIV. PTERIDOPHYTA. PLATE XXV. Figs. 1-9. KNOWLTONELLA MAXONI Berry......--eeee eee e reece eet ereees Fragments of fronds from near Glymont, Maryland. 524 PTERIDOPHYTA. PLATE XXVI. Figs. 1-5. KNOWLTONELLA MAXONI Berry........... cece eee cence eee eeee 235 1. Tip of pinna from near Widewater, Virginia. 2-5. Specimens from same locality showing character of pinnules and habit of branching of pinne. 525 LOWER CRETACEOUS, PLATE Xxvi, MARYLAND GEOLOGICAL SURVEY. PLATE XXVII. PAGE Figs. 1-6. KNOWLTONELLA MAXONI Berry............ 000: eee c cence cues 235 Specimens showing character of pinne and habit of branching from near Glymont, Maryland. 526 PLATE XXVIII. PAGE Figs. 1, 2. Craneputienis PARVA FPontainG..0. cecccncavcn ceaou cuewes vows 250 Specimens from Vinegar Hill, Maryland (after Fontaine). Figs. 3, 4. DICKSONIOPSIS VERNONENSIS (Fontaine) Berry............... 237 3. Fruiting specimen. White House Bluff, Virginia (after Fontaine). 4. Arlington, Maryland (after Fontaine). Figs. 5, 6. ASPLENIOPTERIS PINNATIFIDA Fontaine....................6.. 265 5. Fruiting specimen from Fredericksburg, Virginia. 6. Pinnules of same. X 4. MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE XXVIII SUS = x Ok aN V/) PTERIDOPHYTA. PLATE XXIX. Figs. 1, 2. CLaADoPHLEBIS BROWNIANA (Dunker) Seward............ 1. Sterile frond, Vinegar Hill, Maryland (after Fontaine). 2. Fertile frond, same locality (after Fontaine). Fig. 3. CLADOPHLEBIS CONSTRICTA Fontaine................--.+-00-- Specimen from Chinkapin Hollow, Virginia (after Fontaine). Figs. 4-6. CLADOPHLEBIS VIRGINIENSIS Fontaine..................5. Specimens from Arlington, Maryland (after Fontaine). 528 LOWER CRETACEOUS, PLATE XXIX. “MARYLAND GEOLOGICAL SURVEY. Ke, & iy / OI; \ V9 LUD * aaah OO: OK is A LB ODO" aN Vee ES a o Cockayne, Boston. PLATS LXII. Figs. 1, 2. NaGEetopsis zAMIoIDES Fontaine Fredericksburg, Virginia. 661 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE LXil. GYMNOSPERM&, Cockayne, Boston. PLATH LXIII. PAGE Figs. 1, 2. NAGEIOPSIS ZAMIOIDES Fontaine................. 0c cece eee 386 Fredericksburg, Virginia. Figs. 3, 4. NAGEIOPSIS ANGUSTIFOLIA Fontaine..........0: esse eee eee eres 389 Baltimore, Maryland (after Fontaine). 562 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE LXiIll. GY¥.MNOSPERM 4. PLATE LXIV. Figs. 1-6. BRACHYPHYLLUM CRASSICAULE Fontaine...... seu 1. Ft. Foote, Maryland (after Fontaine). 2-5. 72-Mile post, Virginia (after Fontaine). 6. Near Glymont, Maryland. 563 LOWER CRETACEOUS, PLATE LXIV. MARYLAND GEOLOGICAL SURVEY. GYMNOSPERM. PLATH LXV. PAGE Fig. 1. BraAcHYPHYLLUM MACROCARPUM Newberry..............000eeee 394 From Raritan formation at South Amboy, New Jersey (after Hollick and Jeffrey). Fig. 2. BRACHYPHYLLUM MAMILLARE, Brongniart............-..-..e000- 394 A specimen of this species which is the type of the genus, from the Jurassic of France (after Saporta). Fig. 38. BRACHYPHYLLUM OBESUM Heer......... 0... cece eee eee eee eens 394 From the Aptian of Portugal (after Saporta). Figs. 4, 5. BracHYPHYLLUM PARCERAMOSUM Fontaine................0- 395 4. Telegraph Station, Virginia (after Fontaine). 5. From the Trinity of Texas (after Fontaine). 564 LOWER CRETACEOUS, PLATE LXV. MARYLAND GEOLOGICAL SURVEY. RY ~ TES ors o, STE GYMNOSPERM&, PLATE LXVI. Figs. 1-7. PINUS VERNONENSIS Ward...........c cece cece eee eect eneees 401 1, la, 1b. Seeds from Mt. Vernon, Virginia (after Fontaine). 2, 2a, 2b. Seeds from Ft. Foote, Maryland (after Fontaine). 3. Conescale from near Widewater, Virginia, viewed from dorsal side. 3a. Same viewed laterally. 4-7. Cones from near Widewater, Virginia. 565 MARYLAND GEOLOGICAL SURVEY, LOWER CRETACEOUS, PLATE LXVI, GYMNOSPERMZ&., Cockayne, Boston. PLATE LXVII. PAGE Figs. 1-4. ABIETITES MACROCARPUS Fontaine............0: cece cece cence 405 1-3. Vinegar Hill, Maryland (after Fontaine). 4, Lansdowne, Maryland (after Fontaine). Figs. 5, 6. ABIETITES MARYLANDICUS Fontaine............. ccc e eee neces 406 Vinegar Hill, Maryland (after Fontaine). Fig. 7. ABIETITES LONGIFoLIUS (Fontaine) Berry..............0-2ceeeee 407 Federal Hill, Maryland (after Fontaine). 566 MARYLAND GEOLOGICAL SURVEY. LOWER CRETACEOUS, PLATE LXVII. GYMNOSPERMZ. PLATH LXVIII. Figs. 1-6. CUPRESSINOXYLON WaARDI Knowlton, Clifton (Baltimore) . Transverse section. X 50. The same. X 200. . Tangential section. X 50. The same. X 200. . Radial section. xX 50. . The same. X 200. amnranwre 567 LOWER CRETACEOUS, PLATE LXVIIl. MARYLAND GEOLOGICAL SURVEY, [i ee ae oS) ad GYMNOSPERM&. Cockayne, Boston. PLATE LXIX. PAGE Figs. 1-6. CurkesstnoxyLton McGeer Knowlton. Washington, D. C. (after Knowlton) 1. Transverse section showing annual ring. a, cells of fall wood; b, typical cell of spring wood; c, large intercellular space; d, smaller intercellular spaces. X 67. 2. Tangential section. a, resin-duct; b, bordered pits on tangential walls; c, sections of pits of radial walls. xX 67. 8. Radial section. a, point at which the structure has disappeared; b, medullary rays, mostly showing oblong pores. X 67. 4, Radial section. Same section as Fig. 3. X 242. a, pits on walls of medullary rays; 0, pits on walls of tracheids. 5. Transverse section further enlarged. a, medullary ray; b, cells of spring wood; c, section of pits on radial walls; d, section of pits on tangential wall. x 242. 6. Tangential section. a, resin-duct; b, bordered pits on tracheids; c, bordered pits on resin-duct connected by spiral lines. Figs. 7, 8. CUPRESSINOXYLON WaARDI Knowlton. B. & O. R. R. Cut, D.C. (after Knowlton): . « ssicccwimvarcianc ident enoaarmed areas 415 7. Radial section. a, medullary rays; b, single row of pits on tra- cheids. xX 67. 8. Tangential section. a, resin-duct; b, medullary two cells broad. X 67. 568 LOWER CRETACEOUS, PLATE LXIX. MARYLAND GEOLOGICAL SURVEY. wy x : HA . 200000 08S PERE S= 4 ¢ oo DOL Pl? @0000000 acssacesce® lS eS ” a 0 ols fo 10} lol] o [ jaloo = [oo 30 oe = =< OO aS SSS SS £ y % e == == = OOOO = s 20 @000_ © , TITY anthraciticus, 120. argonnensis, 145. aspera, 106. Briarti, 109. Crameri, 134, depressa, 109. Hirikiana, 134. elliptica, 132. elongata, 106. exogyra, 444. gibbosa, 109. gracilis, 106. Heeri, 109. lingulata, 134. mammiilifer, 139, 145. Olafiana, 134. Omailii,. 109. Peterseni, 134, 169, 407. - premonticola, 145. prohalepensis, 145. Quenstedti, 111. rhombifera, 106. Saportana, 145. schista, 402. shastensis, 124. sp., 126, 136. submarginata, 106. susquensis, 120, 138, 141, Toillezi, 109. vernonensis, 92, 158, 168, 397, 401, 402, 403, 406, 565. wohlgemuthi, 145. Piteairnia primeva, 111. Pitoxylon argonnense, 145. infracretaceum, 145. Thomasi, 145. Pityocladus, 117. Pityolepis, 117. Pityophyllum, 117. Pityospermum, 117. Pityostrobus, 117. Plantaginopsis, 456. hs Plantaginopsis marylandica, 94, 158, 170, 456, 578, 579, Plantago, 457. PALEONTOLOGICAL INDEX 617 Platanophyllum, 489. Platanophyllum crassinerve, 490. Platanus, 481. Platycerium, 496. Platylepis, 313. Platypoda, 211, Platypterygium, 360. Platypterygium densinerve, 362 Rogersianum, 362, 363. Pleurocelide, 190. Pleuroceelus, 66, 174, 175, 177, 178, 188, 197. Pleurocelus altus, 89, 175, 200, 203, 517, 518. nanus, 89, 174, 175, 188, 201, 203, 510, 518, 514, 515, 516, 517. Poacites, 105, 135, 148. Poacites acicularis, 127. borealis, 134. cercalinus, 127. gemellinervis, 104. levis, 143. paucinervis, 104. *s plurinervius, 139. plurinervulosus, 127. striatifolius, 104, 105. tenellus, 104. Podocarper, 375, 380, 383, Podocarpus, 365, 375, 382, 383. Podozamites, 63, 71, 150, 335, 336, 344, 345, 380, 381, 382, 388. Podozamites acutifolius, 92, 136, 168, 338, 339, 552. acutus, 104, 127. equalis, 111. affinis, 169, 337, 338. angustifolius, 339, 340, 342. distantinervis, 92, 120, 154, 157, 168, 340, 342, 345, 346, 347, 552. Eichwaldi, 338. ellipsoideus, 104, 148, 169, 337. gracilior, 143. grandifolius, 349, 350. -Henriquesi, 143. Hoheneggeri, 130. x inequilateralis, 92, 120, 154, 157, 168, 336, 337, 552. Knowltoni, 92, 157, 159, 168, 339, 340, 552. lanceolatus, 92, 116, 160, 341, 342, 552. lanceolatus latifolia, “116. lanceolatus minor, 116. latipennis, 120. linearis, 104. ‘ minor, 342. modestior, 143. nervosa, 120, 341. obovatus, 130. obtusifolia, 336. ovatus, 338. oviformis, 104. pedicellatus, 340, 341, 342. proximans, 341. pusillus, 116, 169, 337. sp., 116, 136. subfalcatus, 92, 168, sei 552. Zittellii, 130. Polypodiacem, 221, 239, 241, 261. Polypodites Mantelli, 131. Polypodium, 285. Polypodium Hochstetteri, 114. Polystichum, 241. Populites, 465. Populophyllum, 71, 459. Populophyllum hedereforme, 461. menispermoides, 458, 461. minutum, 94, 158, 170, 460, 580. reniforme, 94, 158, 160, 170, 461, 496, 580. Populus, 135, 158, 457, 459, 460, 461. Populus arctica, 458. auriculata, 458. eyclophylla, 126. potomacensis, 94, 158, 170, 458, 461, 580. primeva, 133, 134, 458. Ricei, 124. Zaddachi, 458. Porosus, 296. Prepinus, 407. Priconodon, 67, 176, 177, 207. Priconodon crassus, 89, 176, 177, 207, 519. Prionodesmacea, 213. Proangiosperme, 105. Protea, 494. x Proteephyllum, 64, 148, 494, 495, 497, ° 500, 502. Proteephyllum californicum, 123. dentatum, 493, 494. ellipticum, 499. oblongifolium, 505, 506. orbiculare, 496, 498. ovatum, 94, 154, 157, 170, 499. reniforme, 94, 154, 157, 170, 496, 498. sp., 505. tenuinerve, 499., Uhleri, 477. Proteophyllum, 498. és Proteophylum daphnoides, 144, demersum, 144. dissectum, 143. leucospermoides, 143. oblongatum, 144. oxyacanthemorphum, 143. truncatum, 144. Protocedroxylon araucarioides, 118. Protophyllum, 498. 618 PALEONTOLOGICAL INDEX Protopiceoxylon extinctum, 118. Protopteris, 296, 297. Protopteris Buvigniere, 106, 145. punctata, 111. Witteana, 108, 111. wohlgemuthi, 145. Protorhipis, 128, 148, 163, 462, 494, 495, 496, 497. Protorhipis asarifolia, 497. Choffati, 127, 496. cordata, 134, 171, 462, 496. Fisheri, 120. Remeri, 110. Psammopteris knorrieformis, 132. Psaronius, 297. Pseudo-araucaria Lamberti, 145. Loppineti, 145. major, 145. Pseudoctenis, 348. Pseudoctenis lathiensis, 349. Pseudofrenelopsis, 422. Pteridoleimma phycomorpha, 143, spoliatum, 104. tripartitum, 104. Pteridophyta, 71, 181, 214. Pteridosperme, 147, Pteris Albertsili, 252. Albertini, 252. frigida, 134. longipennis, 293. sp., 116, 253. Pterocelastrus, 474. Pterophyllum, 331, 334, 244, 360. Pterophyllum blechniforme, 111. Buchianum, 332. concinnum, 134. Ernestine, 113. fastigiatum, 113. Germari, 111. lepidum, 134. lowryanum, 123. Lyellianum, 111. montanense, 120. saxonicum, 111, 332. Ptilophyllum cutchense, 116. Ptilozamites. 351. Q Quercophyllum tenuinerve. 504. wyomingensis, 141. Quercus coriacea, 126. flexuosa, 126. spathulata, 132. R -Ranales, 320, 462. Raumeria, 313. Ravenalospermum incertissimum, 144, Reptilia, 181, 183. Reussia pectinata, 132. Rhamnales, 481. Rhipidopteris, 218, 221, 224. Rhizocaulon, 105, 128, 148. Rhizocaulon elongatum, 104, 127. vertus, 104. Rhizomopteris sp., 117. Rhizomopteris Etheridgei, 292. Rhynchogoniopsis neocomiensis, 115. Rogersia, 64, 148, 497, 499, 503. - Rogersia angustifolia, 94, 157, 170, 469, 501, 502. ; angustifolia parva, 94, 155, 157, 170, 501. longifolia, 94, 157, 170, 468, 500. Royena, 146. Rudiste, 99. Ruffordia, 63, 71, 215, 222, 230. Ruffordia acrodentata, 90, 166, 230, 522. Gepperti, 90, 104, 108, 110, 111, 128, 132, 148, 154, 156, 166, 231, 232, 522. Goepperti latifolia, 108, 230. Ss Sagenopteris, 131, 284, 285, 286. Sagenopteris acutifolia, 108. . elliptica, 90, 1238, 124, 125, 166, 287, 288. latifolia, 90, 154, 156, 166, 286. Mantelli, 108, 110, 111, 123, 130, 167, 287, 289. neocomiensis, 111. nervosa, 123,124. Nilsoniana, 125, 284, 285. oblengifolia, 125. oregonensis, 124. paucifolia, 289. rhoifolia, 284. sp., 287. undulata, 285. virginiensis, 90, 154, 156, 166, 289. Sagittaria latifolia, 452. rigida, 452. Victor-Masoni, 452, 453. Salicacer, 457. Salicales, 457, Saliciphyllum californicum, 124, ellipticum, 476, 505. longifolium, 501. pachyphyllum, 124, parvifolium, 476. Salix assimilis, 144. infracretacica, 143. perplexa, 126. retinenda, 143. Sapindophyllum brevior, 144. subapiculatum, 144. PALEONTOLOGIOAL INDEX _ 619 Sapindaces, 467, 468. Sapindales, 467. Sapindopsis, 71, 362, 467, 468, 469, 473. te “Sapindopsis brevifolia, 94, 158, 170, 473, 586. : ‘ cordata, 468, 505. elliptica, 468, 500. magnifolia, 94, 158,'170,.468, 470, 471, 472, 585, 586, 587. obtusifolia, 471. oregonensis, 361. - parvifolia, 469, 470.. tenuinervis, 471, 473. ; variabilis, 94, 141, 158, £62, 170, 467, 469, 472, 582, 588, 584. Sarcostrobilus Paulini, 129. Sargassites Partschii, 130. Sassafras, 481, 483, 485, 487, 489. Sassafras acutilobum, 488. arctica, 487. Dilobatum, 94, 158, ‘170, 484, 592. cretaceum, 126, 486. 2 vretaceum heterolobum, 486. Ferretianum, 484, mudgii, 487.- parvifolium, 94, 158, 170, 486, 592, . 593. ' : potomacensis, ‘94, 158, 160, ee 487, 593. protophyllum, 143- i171, 488." Sauropoda, 66, 188. Schizea, 218. : Schizeacex,- 147, 214, 217, 218, 221, 222, 230, 241. , in Schizea elegans, 214, 219, 222, 871... dichotoma, 222, 371. Schizeopsis, 63, 71, 214, 219. Schizeopsis americana, 90, 154, 156, 166, 216, 222, 229, 521. expansa, 216. Schizeopteris mesozoica, 215. Schizolepis cylindrica, 118. retrofiexa, 118. Schizoneuropsis posthuma, 113. Sclerophyllina, 219. Scleropteris, 63, 71, 238, Ais 4 353, 358. Scleropteris debilior, 104. dentata, 355. distantifolia, 138. elliptica, 90, 166, 300, 538. elliptica longifolia, 300. rotundifolia, 138. tenuisecta, 238. vernonensis, 237, 264. virginica, 300. Scolopendrium, 292. Sedites Rabenhorstii, 444. Selaginella, 306, 308. Selaginellacern, 306, Selaginella arctica, 308. dichotoma, 308. marylandica, 90, 157, 166, 3807, 540. ‘ Senftenbergia, 215." Sequoia, 63, 71, 346, 365, 391, 412, 431, 482,434, 439, 442, Sequoia. acutifolia, 120. 3 ambigua, 94, 121, 124, 134, 141, 170, 487, 438, 439, 441, 449, _ 450, 451, 577., Couttsie, 445, * cycadopsis, . 365. ; delicatula, 94, 154, 157, 170, 448. densifglia, 445. | ‘falcifolia, 113. fastigiata, 121, “4387, . gracilis, 134, 435, -436, 437, 449, 451, inferna, 446. . Langsdorfii, 125. lusitanica, 104, 139.. pagiophylloides, 136, 435.. pectinata, 448. E Reichenbachi,, 94, 121, 123; 124, 130, 134, 141, 159, 170, aes 445, 446, 449, 576. ‘Reichenbachi longifolia, 445. rigida, 94, 121, 134, 154, 157, 170, 447, 448, 577. ; sempervirens, 443, 444. Smittiana, 121, 184, sp., 138, 445: subulata, 108, 447, 448, 449. subulata lusitanica, 105; 143. washingtoniana; 443, 444. “Woodwardii, 447.. —~ Sequoiites-Gardneri, 145. ovalis, 145. -- Sigillaria, 306. Spermatophyta, 313. Spheria phylostichoides, 1438. Spherococcites meyrati, 102. Sphenolepidium, 431. Sphenolepidium debile, 105, 128, 143. dentifolium, 449, 450. Kurrianum, 432, 433, parceramosum, 433.- recurvifolium, 449. Sternbergianum, 435, 436, 437. Sternbérgianum’ densifolium, 435, 436, 440. | subulatum, 108. : virginicum, 433. Sphenolepis, 35, 63, 71, 144, 481, 442. Sphenolepis imbricata, 113. Kurriana, 94, 105, 108, 111, 112, 118, 122, 128, 139, 142, 143, 144, 168, 430, 432, 433, 484, 489, 441, 442, 573. : ’ 620 .PALEONTOLOGIOAL INDEX sp., 108, 121. Sternbergiana, 94, 105, 108, 111, 112, 113, 121, 124, 128, 130, 136, 139, 148, 144, 170, 435, 436, 437, 438, 451, 574. Sphenopteris, 215, 221, 222, 230, 233, 281, 299. Sphenopteris acrodentata, 230. acutidens, 128. adiantifrons, 111, 231. aneimieformis, 128. angustiloba, 128, 139. antipodum, 275. auerbachi, 132, 232. borealis, 134. eapillaris, 105. cercalensis, 128. Choffatiana infracretacica, 105. cordai, 128, 270. crenularia, 143. cuneifida, 105, 128, 167, 222, 228. debiliformis, 105. debilior, 148, 167, 222, 224. DeGeeri, 118. Delgadoi, 106. _ delicatissima, 110, 111. dissectifolia, 105. dissectiformis; 105, 167, 228. Fittoni, 106, 108, 110, 111, 114. flabellina, 143, 167, 226, 228. flabellinervia, 105. flabellisecta, 105, 167, 222, 227. Fontainei, 108. : fragilis, 134. ginkgoides, 105. Gepperti, 231, 232, 270, 271, 275, 281. Gomesiana, 105, 270. grevilloides, 134. Hartlebeni, 231. involvens, 143. Jugleri, 231. latiloba, 273. lepida, 134. linearisecta, 128. lobulifera, 105, 128. longifolia, 231. lupulina, 105. Mantelli, 267, -269, 270, 271, 274, 275. pachyphylla, 282, 233. . plurinervia, 105, 128, 138, 139, 270. polyclada, 128.. pseudo-cordai, 143. pseudolepida, 105. pygmea, 128. recurrens, 143. Reemeri, 274. spatulata, 232, 233. sp., 35, 114, 121, 232. sp. A., 118, 277. sp. B., 118. subtilinervis, 105. tenellisecta, 167, 222, 227. tenera, 274. eS tenuicula, 116, 232. tenuifissa, 139, 143, 167, 222, 228. thyrsopteroides, 232, 233. valdensis, 136, 232, 233. Spirangium Jugleri, 111. Sporophyta, 214. : Stachypteris minuta, 105. Stangeria, 357. Stegosauria, 67, 177. Stegosauride, 207. tie Stegosaurus, 176, 207, 208, 209, 210. Stegosaurus ungulatus, 209. Stenopteris, 358. Stenopteris desmomera, 366. Stenorrhachis clavata, 118. Stephanoceratide, 115. Sterculia, 71, 485. Strobilites, 411. T Tenidium pinnatisectum, 129. lusitanicum, 139. Teenioglossa, 211, Teniopteris, 63, 71, 110, 290, 291, 360, 361. Teniopteris arctica, 114. - auriculata, 90, 154, 156, 166, 293. Bertrandi, 290. Beyrichii, 108, 118. Beyrichii superba, 108. Dawsoni, 108. Lundgreni, 118. Miinsteri, 290, 292. nervosa, 90, 154, 156, 166, 293,° 294, 576. plumosa, 125. sp., 123. vittata, 290. z6bingiana, 130. . Taonurus incertus, 121. Taonurus sp., 135. Taxacem, 147, 149, 152, 374, 375. Taxer, 374, 375. Taxites, 375, 376, 379. Taxites falcatus, 365. sp., 114. Taxodiex, 390, 431. Taxodium, 381. Taxodium brookense, 429. brookense angustifolium, 429. -cuneatum, 121. — denticulatum, 433. expansum, 433, 439. fastigiatum, 433. PALEONTOLOGICAL INDEX 621 Yramosum, 428. Taxoxylon sp., 125. Taxus, 381. Teleodesmacea, 213. Tempskya, 71, 295. Tempskya Schimperi, 108, 111, 167, 296, 295. varians, 296. Whitei, 90, 157, 166, 298, 536, 537. Testudinata, 66, 177. Thallophyta, 147. Theropoda, 183. Thinnfeldia, 128, 124, 801, 302. Thinnfeldia arctica, 118. Fontainei, 90, 166, 302, 539. granulata, 90, 166, 303, 305, 539. marylandica, 90, 155, 156, 166, 305, 539. montanensis, 249. rhomboidalis, 301. rotundiloba, 90, 154, 166, 305, 539. variabilis, 249, 302. Thuia graminea, 427. Thuites Choffati, 432. Germari, 432. gramineus, 426. Hoheneggeri, 420. Kurrianus, 432. sp., 35. Thuyites debilis, 139. densior, 105. ecarinatus, 132. Meriani, 134. pulchelliformis, 105, 139. valdensis, 108. Thuyoxylon americanum, 136. Thylloxylon irregulare, 118. Thymeleales, 483. Thyrsopteris, 268, 269, 271, 272. Thyrsopteris alata, 281, angustifolia, 275. angustiloba, 281. bella, 282. brevifolia, 278. brevipennis, 273. crenata, 273. - decurrens, 281, 282. densifolia, 281, 282. dentata, 278. dentifolia, 275. distans, 282. divaricata, 273. erassinervis, 279, 280. elliptica, 282, 283. elongata, 267, 277, 281. heteroloba, 279. heteromorpha, 232. heterophylla, 278. ineequipinnata, 282. insignis, 275, 276. insignis angustipennis, 275. Meekiana, 279, 280. Meekiana angustiloba, 281, 282. Microloba, 282. microloba alata, 282, 283. microphylla, 275. nana, 278. nervosa, 279, 280. obtusiloba, 280. pachyphyllum, 278. pachyrachis, 282.. pecopteroides, 279, 280. pinnatifida, 282. rarinervis, 276. retusa, 278. rhombifolia, 282, rhombiloba, 282. sphenopteroides, 278. squarrosa, 278. sp., 116. varians, 282. virginica, 281. Todites Williamsoni, 250. Torreya Dicksoniana, 135. parvifolia, 135. venusta, 116. Trigonia, 115. Tsugites magnus, 145. Tumion, 375, 381. Tysonia, 313. Tysonia marylandica, 320. U Ulmiphyllum densinerve, 142. Ulospermum, 366. Umbellales, 488. Unio, 213. Unio potapscensis, 213, 520. Unionide, 213, Vv Vertebrata, 183. Vesquia Tournaisii, 376. Viburnum vetus, 144. Vitacer, 481. Vitiphyllum, 482. Vitiphyllum crassifolium, 483. multifidum, 482, 483. parvifolium, 482, 483. Vitis, 482. Viviparide; 212. Viviparus, 212, Viviparus arlingtonensis, 89, 212, 520. marylandicus, 89, 212, 520. WwW Weichselia, 130, 146. Weichselia Ludovice, 112, 113. Mantelli, 257. reticulata, 106, 108, 110, 112, 113, 115, 129, 131, 142. 622 PALEONTOLOGICAL INDEX Widdringtonia, 421, 427, 428. Widdringtonites, 71, 126, 158, 390, 421, 426, 427, 428, 434, 437, 440. Widdringtonites curvifolius, 435. debilis, 105. Dunkeri, 435. gracilis, 130, 434. Haidingeri, 432. Kurrianus, 432. oblongifolius, 430. pygmeus, 105. ramosus, 94, 121, 158, 170, 427, 428, 429, 430, 440, 572. Reichii, 171, 427, 429, 430. subtilis, 428. Ungeri, 427. Williamsonia, 63, 105, 319. Williamsonia Bibbinsi, 405. gigas, 320. minima, 105. pheenicopsoides, 138. sp., 121. virginiensis, 819. Withamia Saporte, 108. Xx Xenoxylon phyllocladoides, 118. latiporosum, 118. Xyridales, 456. Y Yatesia, 108, 313. Yatesia Guillaumoti, 145. Yuccites, 105. Yuccites fractifolius, 105. 4 z Zamia, 335, 343, 346, 368. Zamia lanceolata, 341. . washingtoniana, 342, 345, 346. Zamiophyllum, 381. Zamiophyllum Buchianum, 332, Naumanni, 116. Zamiopsis, 351, 354. Zamiopsis dentata, 92, 168, 355, 357, 555. insignis, 352, 356, 357. laciniata, 92, 154, 157, 168, 356, = 358. longipennis, 356. ‘petiolata, 92, 154, 157, 168, 357. pinnatifida, 355. Zamiostrobus, £97. ZamNostrobus crassus, 115. index, 115. Loppineti, 145. Zamites, 63, 71, 150, 831, 332, 385, 336, 343. . Zamites acutipennis, 121, 135. affinis, 130. africana, 114. angustifolius, 339. apertus, 121. arcticus, ‘121, 123, 135. borealis, 121, 135, 138. brevipennis,-135, 138. ’ Brongniarti, 106. . _Buchianus, 108, 333. Carruthersi, 108, 169, 346. Carruthersi latifolius, 108. = crassinervis, 92 125, 154, 157, ea 347, 553. . distantinervis, 346. distans, 335. globuliferus, 135. Geepperti, 130. iburgensis, 112. Kaufmanni, 102. lanceolata, 335. lanceolatus, 341. montana, 121. © “Morrisii, 114. nervosus, 112, 130. . ovalis, 338, 347. ovatus, 130. , pachyneurus, 130. recta, 114. rubidgei, 114, -- sp., 118, 142, 347. speciosus, 113, 135. tenuinervis, 92, 128, 124, 125, 136, 168, 340, 345, 346, 553.