ILLINOIS STATE GEOLOGICAL SURVEY I II I I I I I I I 3 3051 00000 1234 URBANA v 3 i 0$ s STATE OF ILLINOIS DWIGHT H. GREEN, Governor DEPARTMENT OF REGISTRATION AND EDUCATION FRANK G. THOMPSON, Director DIVISION OF THE STATE, GEOLOGICAL SURVEY M. M. LEIGHTON, Chief URBANA BULLETIN NO . 70 PENNSYLVANIAN OSTRACODES OF ILLINOIS BY CHALMER L. COOPER v»°*J?£T iURVE^ PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS URBANA, ILLINOIS 1946 ORGANIZATION STATE OF ILLINOIS HON. DWIGHT H. GREEN, Governor DEPARTMENT OF REGISTRATION AND EDUCATION HON. FRANK G. THOMPSON, Director BOARD OF NATURAL RESOURCES AND CONSERVATION HON. FRANK G. THOMPSON, Chairman NORMAN L. BOWEN. D.Sc, LL.D., Geology ROGER ADAMS, Ph.D., D.Sc, Chemistry LOUIS R. HOWSON, C.E., Engineering CARL G. HARTMAN, Ph.D., Biology EZRA JACOB KRAUS, Ph.D., D.Sc, Forestry ARTHUR CUTTS WILLARD, D.Engr., L.L.D. President of the University of Illinois GEOLOGICAL SURVEY DIVISION M. M. LEIGHTON, Chief H0162) SCIENTIFIC AND TECHNICAL STAFF OF THE STATE GEOLOGICAL SURVEY DIVISION 100 Natural Resources Building, Urbana M. M. LEIGHTON, Ph.D., Chief Enid Townley, M.S., Assistant to the Chief Velda A. Millard, Junior Asst. to the Chief Helen E. McMorris, Secretary to the Chief Effie Heitishee, B.S., Geological Assistant GEOLOGICAL RESOURCES Ralph E. Grim, Ph.D., Petrographer and Principal Geologist in Charge Coal G. H. Cady, Ph.D., Senior Geologist and Head L. C. McCabe, Ph.D., Geologist (on leave) R. J. Helfinstine, M.S., Mech. Engineer Charles C. Boley, M.S., Assoc. Mining Eng. Byran Parks, M.S., Asst. Geologist Earle F. Taylor, M.S., Asst. Geologist (on leave) Ralph F. Strete, A.M., Asst. Geologist Robert M. Kosanke, M.A., Asst. Geologist Robert W. Ellingwood, B.S., Asst. Geologist George M. Wilson, M.S., Asst. Geologist Arnold Eddings, B.A., Research Assistant (on leave) Raymond Siever, B.S., Research Assistant (on leave) John A. Harrison, B.S., Research Assistant (on leave) Mary E. Barnes, B.S., Research Assistant Margaret Parker, B.S., Research Assistant Elizabeth Lohmann, B.F.A., Technical Assistant Oil and Gas A. H. Bell, Ph.D., Geologist and Head Frederick Squires, B.S., Petroleum Engineer Stewart Folk, M.S., Assoc. Geologist (on leave) Ernest P. Du Bois, Ph.D., Assoc. Geologist David H. Swann, Ph.D., Assoc. Geologist Virginia Kline, Ph.D., Assoc. Geologist Paul G. Lucktiardt, M.S., Asst. Geologist (on leave) Wayne F. Meents, Asst. Geologist James S. Yolton, M.S., Asst. Geologist Margaret Sands, B.S., Research Assistant Industrial Minerals J. E. Lamar, B.S., Geologist and Head H. B. Willman, Ph.D., Geologist Robert M. Grogan, Ph.D., Assoc. Geologist Robert T. Anderson, M.A., Asst. Physicist Margaret C. Godwin, A.B., Asst. Geologist Clay Resources and Clay Mineral Technology Ralph E. Grim, Ph.D., Petrographer and Head Richards A. Rowland, Ph.D., Asst. Petrographer (on leave) William A. White, B.S., Research Assistant Groundwater Geology and Geophysical Exploration Carl A. Bays, Ph.D., Geologist and Engineer, and Head Robert R. Storm, A.B., Assoc. Geologist Arnold C. Mason, B.S., Assoc. Geologist (on leave) Merlyn B. Buhle, M.S., Asst. Geologist M. W. Pullen, Jr., M.S., Asst. Geologist. Charles G. Johnson, A.B., Asst. Geologist (on leave) Margaret J. Castle, Asst. Geologic Draftsman Robert N. M. Urash, B.S., Research Assistant Areal and Engineering Geology George E. Ekblaw, Ph.D., Geologist and Head Richard F. Fisher, M.S., Asst. Geologist Stratigraphy and Paleontology J. Marvin Weller, Ph.D., Geologist and Head Chalmek L. Cooper, Ph.D., Geologist Heinz A. Lowenstam, Ph.D., Assoc. Geologist Subsurface Geology L. E. Workman, M.S., Geologist and Head C. Leland Horberg, Ph.D., Assoc. Geologist Frank E. Tippie, B.S., Asst. Geologist Paul Herbert, Jr., B.S., Asst. Geologist Marvin P. Meyer, B.S., Asst. Geologist Elizabeth Pretzer, A.B., Research Assistant Ruth E. Roth, B.S., Research Assistant Physics R. J. Piersol, Ph.D., Physicist B. J. Greenwood, B.S., Mech. Engineer GEOCHEMISTRY Frank H. Reed, Ph.D., Chief Chemist (on leave) Carol J. Adams, B.S., Research Assistant Coal G. R. Yohe, Ph.D., Chemist and Head* Herman S. Levine, B.S., Research Assistant Indust?~ial Minerals J. S. Machin, Ph.D., Chemist and Head. Delbert L. Hanna, A.M., Asst. Chemist. Fluorspar G. C. Finger, Ph.D., Chemist and Head Oren F. Williams, B.Engr., Asst. Chemist Chemical Engineering H. W. Jackman, M.S.E., Chemical Engineer and Head P. W. Henline, M.S., Assoc. Chemical Engineer James C. McCullouuh, Research Associate Donald M. Fort, M.S., Asst. Chemist James H. Hanes, B.S., Research Assistant (on leave) Leroy S. Miller, B.S., Research Assistant (on leave) X-ray and Spectrography W. F. Bradley, Ph.D., Chemist and Head Analytical 0. W. Rees, Ph.D., Chemist and Head* L. D. McVicker, B.S., Chemist Howard S. Clark, A.B., Assoc. Chemist William F. Wagner, M.S., Asst. Chemist Cameron D. Lewis, B.A., Asst. Chemist William T. Abel, B.A., Research Assistant Melvin A. Rebenstorf, B.S., Research Assistant Jean Lois Rosselot, A.B., Research Assistant MINERAL ECONOMICS W. H. "Voskuil, Ph.D., Mineral Economist Douglas F. Stevens, M.E., Research Associate Nina Hamrick, A.B., Research Assistant Ethel M. King, Research Assistant PUBLICATIONS AND RECORDS George E. Ekblaw, Ph.D., Geologic Editor Chalmer L. Cooper, Ph.D., Geologic Editor Dorothy E. Rose, B.S., Technical Editor Meredith M. Calkins, Geologic Draftsman Beulah Featherstone, B.F.A., Asst. Geologic Draftsman Willis L. Busch, Principal Technical Assistant Portia Allyn Smith, Technical Files Clerk Leslie D. Vaughan, Asst. Photographer *Assistant Chief Chemist in interim of absence of Chief Chemist. Consultants: Ceramics, Cullen W. Parmelee, M.S., D.Sc, and Ralph K. Hursh, B.S., University of Illinois Mechanical Engineering, Seiciii Konzo, M.S., University of Illinois Topographic Mapping in Cooperation with the United States Geological Survey. This report is a contribution of the Stratigraphy and Paleontology' Division. July 15, 1945 Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/pennsylvanianost70coop CONTENTS Page Introduction 9 Acknowledgments 9 Stratigraphic summary, by J. Marvin Weller 11 Shoal Creek limestone and lower beds 11 Beds above Shoal Creek 12 Stratigraphic distribution 15 Ti Valley series 18 Morrow group 19 Atoka group 19 Des Moines series 20 Cherokee group 21 Marmaton group 23 Missouri series J 27 Bronson group 28 Kansas City group 28 Lansing group 30 Virgil series 31 Douglas group 31 Shawnee group 32 Waubaunsee group 34 Collecting localities 35 Systematic descriptions 39 Acronotellidae 39 Monoceratina 39 Aechminidae 40 Ardmorea 40 Bairdiidae 40 Bairdia 40 Bairdiacypris 53 Bythocypris 55 Coryellites 55 Fabalicypris 59 Macrocypris 61 Microcheilinella 62 Waylandella 63 Cypridae 65 Candona 65 Carbonita 66 Gutschickia 68 Cytheridae 69 Basslerella 69 Cytherellidae 70 Cavellina 70 Page Silenites 15 Sulcella 76 Darwinulidae 78 Darwinula 78 Drepanellidae 78 Cornigella 78 Glyptopleuridae 79 Glyptopleura 79 Healdiidae 79 Healdia 79 Healdiacypris 86 Seminolites 87 Hollinidae 87 Hollinella 87 Kirkbyiidae 97 Amphissites 97 Discoidella 101 Ectodemites 101 Kellettina 103 Kirkbya 104 Kirkbyella 106 Knightina 107 Polytylites 108 Roundyella 108 Kloedenellidae 109 Ellipsella 109 Geisina 110 Hastifaba Ill Jonesina 112 Kloedenella 114 Lochriella 114 Sansabella 114 Sargentina 117 Leperditellidae 117 Cyathus 117 Microparaparchites 118 Paraparchites 120 Paraparchitella 121 Proparaparchites 121 Youngiellidae 121 Moorites 121 References 124 Plates and explanations 127 Index 171 Paunal chart (In pocket) ILLUSTRATIONS Plates Page 1-21 Pennsylvanian ostracodes. . .127-169 Figure 1 Map of Illinois and adjacent por- tions of Indiana and Kentucky showing the Pennsylvanian bor- der in the Eastern Interior basin and localities from which ostracodes were collected 10 2 Table showing relative strati- graphic positions of beds from which ostracodes were collected 16 3 Histogram showing stratigraphic distribution of the ostracode species 18 4 Histogram showing the ostracode species in the Fulda limestone. . 19 5 Histogram showing the ostracode species in the Ferdinand lime- stone 19 6 Histogram showing the ostracode species in the Seville cyclothem 20 7 Histogram showing the ostracode species in the Seahorne zone... 21 8 Histogram showing the ostracode species in the Wiley zone 21 9 Histogram showing the ostracode species in the Liverpool cyclo- them (Oak Grove beds) 22 10 Histogram showing the ostracode species in the Summum cyclo- them (Hanover limestone and associated beds) 23 11 Histogram showing the ostracode species in the St. David zone.. 24 12 Histogram showing the ostracode species in the Craborchard zone 24 13 Histogram showing the ostracode species in the Brereton (Her- rin) cyclothem 24 14 Histogram showing the ostracode species in the Jamestown zone. 25 15 Histogram showing the ostracode species in the Bankston Fork zone 25 16 Histogram showing the ostracode species in the Piasa and Spar- land zones 25 Page 17 Histogram showing the ostracode species in the Lonsdale (Gim- let) zone 26 18 Histogram showing the ostracode species in the Exlin^ zone 27 19 Histogram showing the ostracode species in the Trivoli zone.... 28 20 Histogram showing the ostracode species in the Collinsville zone 28 21 Histogram showing the ostracode species in the Shoal Creek and Hicks zones 28 22 Histogram showing the ostracode species in the "Centralia" zone 29 23 Histogram showing the ostracode species in the Hall and Ma- coupin zones 29 24 Histogram showing the ostracode species in the LaSalle, Living- ston and Millersville zones.... 30 25 Histogram showing the ostracode species in the Cohn zone 31 26 Histogram showing the ostracode species in the Bogota zone .... 31 27 Histogram showing the ostracode species in the Little Vermilion zone 32 28 Histogram showing the ostracode species in the Omega zone 32 29 Histogram showing the ostracode species in the Newton and Shumway zones 33 30 Histogram showing the ostracode species in the Greenup zone... 34 31 Histogram showing the ostracode species in the Woodbury zone.. 34 32 Graph of length-height dimensions of some ''species" of Carbonita 67 33 Graph of length-height dimensions of Sulcella 77 34 Graph of length-height dimensions of Hollinella dentata Coryell.. 90 35 Graph of length-height dimensions of Hollinella limata (Moore).. 93 36 Graph of length-height dimensions of Hollinella oklahomaensis (Harlton) 95 PENNSYLVANIAN OSTRACODES OF ILLINOIS BY Chalmer L. Cooper INTRODUCTION The rapid lateral and vertical changes in lithology and thickness of Pennsylvanian strata in Illinois make it particularly difficult to obtain precise correlations, especially in isolated out- crops where few beds are exposed; therefore various means of correlating these rocks are being continually studied by the Illinois State Geological Survey. These methods include the use of electric logs and time logs on drilling wells in oil and gas development areas, and micro- faunal studies on plant spores and ostra- codes from outcrop and well samples. In addition, other studies based on the smaller Foraminifera, including those on fusulines started by Dunbar and Henbest (1942), are being continued. Work on the Pennsylvanian ostra- codes of Illinois was begun shortly after the completion of similar work on the Chester ostracodes (Cooper, 1941). The present report is based on 178 collec- tions from 120 outcrop localities of 28 fossiliferous zones in the Eastern In- terior basin, largely from type sections or from well known localities where stratigraphic relations are clear. Previ- ous reports on Pennsylvanian ostracodes have been confined largely to short papers which treat restricted faunas or few localities. Exceptions are the works of Kellett (1933-35) and Bradfield (1935). Ostsracodes occur abundantly in many Pennsylvanian fossiliferous zones, and if the stratigraphic ranges of ostra- code genera and species were known, these data would form a basis for cor- relation. Ostracodes possess one great advantage over larger fossils in that large suites of specimens can be obtained easily and quickly from shales in which they are abundant, and specimens can often be recovered from the cores and cuttings of wells. In order to obtain a broad outlook upon the stratigraphic ranges of Penn- sylvanian ostracodes in Illinois, repre- sentative collections were sought in all of the known marine fossiliferous zones. The results of collecting in some zones were disappointing, and in a few in- stances entirely negative, but on the whole an excellent series of collections was obtained from all but the lowest part of the Pennsylvanian system as de- veloped in Illinois. The study reported in the following pages is presented with the purpose of outlining in preliminary fashion what has been learned regarding the ranges of ostracode genera and species. It is not complete, as many de- tails remain to be filled in by future work. Since this study is intended to determine only the occurrence of ostra- codes in well-known zones, any refine- ments of the present stratigraphic classi- fication must await future and more de- tailed work on the questionable horizons. It is planned to continue the ostracode work in an attempt to solve some of the perplexing correlation problems in the Illinois Pennsylvanian. Acknowledgments The wide scope of this report has been possible largely by reason of the gener- ous contribution of two extensive collec- tions of Pennsylvanian ostracodes, both 10 PENNSYLVANIAN OSTRACODES LEGEND LIMIT OF PENNSYLVANIAN FORMATIONS IN EASTERN INTERIOR BASIN COLLECTING LOCALITY Fig. 1 — Outline map of Illinois and adjacent portions of Indiana and Kentucky showing extent of Pennsylvanian strata in the Eastern Interior basin, and location of samples studied for this report. STRATIGRAPHIC SUMMARY 11 in prepared and in washed samples, by H. L. Geis. One collection is composed of over 100 slides of mounted specimens from many fossiliferions Pennsylvanian beds in Illinois. The other collection is made up of several hundred samples from nearly 150 Pennsylvanian and Per- mian type localities and other well- known exposures in the Midcontinent area, from Kansas to Texas. Pennsylvanian ostracode faunas from Indiana University, containing the types described by Bradfield (1935) and Payne (1937), were loaned through the courtesy of J. J.Galloway of the Depart- ment of Geology of that institution. J. Marvin Weller and Harold R. Wan- less have been of continued assistance throughout the progress of the research, giving invaluable aid in the location of outcrops and furnishing measured sec- tions for most of them. Dr. Weller has critically read the manuscript, including the chart of formations (fig. 2, p. 16), and has contributed the section follow- ing, discussing some Pennsylvanian stratigraphic problems in Illinois, espec- ially in the upper part of the system. Mrs. Helen Jeanne Plummer, Mrs. Betty Kellett-Nadeau, and R. V. Hill- ingsworth have also contributed speci- mens and samples from the Midconti- nent for purposes of comparison. Vari- ous former and present members of the Coal Division of the Illinois Survey, namely J. Norman Payne, E. C. Dapples, George Wilson, and Bryan Parks, have collected numerous samples during field work for that Division. Allen F. Agnew assisted on several collecting trips to Pennsylvanian outcrop areas in southern and western Illinois. All col- lections made by others than myself are acknowledged in the section describing - localities (pp. 35-38). Mrs. Ellen Jordan Shannon assisted with the preparation of the manuscript and plates. STRATIGRAPHIC SUMMARY J. Marvin Weller Although more or less detailed strati- graphic studies of the Pennsylvanian system in Illinois have been in almost continuous progress for more than 15 years, many problems remain unsolved, particularly with regard to the correla- tion of beds occurring above the Shoal Creek limestone in different parts of the State. These beds are well exposed in numerous disconnected areas separated by regions of thicker glacial drift where outcrops are rare or absent. However, there are few places where a strati- graphic succession of any important thickness is entirely clear, and conse- quently the building up of a complete stratigraphic sequence is very difficult. Many correlation problems appear to be extremely complex and impossible of solution by field studies alone. This is well illustrated by the very divergent correlations (mostly unpublished) that have been favored by different investi- gators or even by the same person at different times. Most of the localities selected for col- lecting were chosen because the succes- sion of beds there exposed had been care- fully studied and identified. The cor- relations of some of these beds, particu- larly in the upper part of the Pennsyl- vanian system, however, are somewhat uncertain as pointed out above, and a brief statement concerning the present status of some of the problems involved is necessary. Shoal Creek Limestone and Lower Beds The correlations of most fossiliferous beds in the Illinois Pennsylvanian up to and including the Shoal Creek limestone are satisfactorily established. Those which require comment are as follows: Fulda and Ferdinand limestones. — These two zones are not known to occur in Illinois. They have been identified in Indiana, however, and their names are taken from a manuscript report, a 12 PENNSYLVANIA!? OSTRACODES summary of which was published by Franklin (1944). Seville limestone. — The Seville lime- stone of western Illinois has been cor- related with the Curlew limestone of southern Illinois and western Kentucky by Wanless and Weller, but Dunbar and Henbest (1942, p. 20) have con- cluded that the Seville limestone is older than the Curlew. Unfortunately no ostracodes have yet been obtained from the Curlew limestone and associated shales. " Crab or chard" limestone. — This lime- stone is part of a cyclothem which in- cludes the socalled No. 5A coal. It is well developed and apparently persist- ent in southern Illinois but the entire cyclothem is poorly developed and gen- erally unrecognizable elsewhere in the State. The name "Craborchard" is a field term which is not proposed at this time as a permanent stratigraphic name. Pokeberry limestone. — This limestone crops out in a very restricted area west of Illinois River, between No. 6 and No. 7 coals. It is probably equivalent to either the Jamestown or the Bankston Fork limestone of southern Illinois. The latter correlation is favored at this time. Brouillet coal. — This coal crops out in Edgar County near the Indiana state line, between No. 7 and No. 8 coals of Illinois. Fossiliferous marine limestone occurs intermittently both close below and close above it. This is the position of the Gimlet beds of western Illinois, and the recent recognition (Weller et al, 1942, p. 1592) that two cyclothems are represented in the original Gimlet cyclo- them suggests that the fossiliferous zone above the Brouillet coal is equivalent to the Exline limestone. The two limestones associated with this coal are probably the local representatives of the West Franklin limestone of southern Indiana. Shoal Creek limestone. — The names Shoal Creek and Carlinville have been used for prominent limestones that crop out in two areas in southwestern Illinois. Although they have generally been cor- related, their exact equivalence has not been certainly established. Hicks cyclothem, etc. — The Pennsyl- vanian succession between the Gimlet and LaSalle cyclothems, exposed in the upper Illinois valley, is quite different from that developed in other parts of Illinois. It contains several prominent but thin limestones which are the basis for the recognition of several incomplete cyclothems to which the field names Turner, Hicks, and Hall have been ap- plied by H. B. Willman. These have been tentatively correlated, according to their relative stratigraphic positions, with better developed cyclothems farther south. Beds Above Shoal Creek Limestone Considerable confusion exists regard- ing the correlation of some of the strata younger than the Shoal Creek limestone and the proper application of names that have been proposed for them. This confusion is caused largely by the as yet unsolved problem of the correlation of the Omega and Greenup limestones. Weller and Newton believed those beds to be equivalent, but Dunbar and Hen- best (1942, p. 28) concluded that the Greenup is considerably younger than the Omega. This latter interpretation now appears more probable. A good stratigraphic section clearly shows the following sequence of cyclo- thems above the supposed Shoal Creek limestone in Edgar and Clark counties of eastern Illinois (Dunbar and Hen- best, 1942, p. 16) : 8. Upper Bogota 7. Lower Bogota 6. Cohn 5. Upper Livingston 4. Lower Livingston 3. Macoupin 2. Flannigan 1. Shoal Creek In Macoupin County of southwestern Illinois a somewhat comparable section above the Carlinville limestone is classi- fied as follows: 1 burroughs and Shaw Point are local names pro- posed in a manuscript report on the Carlinville quad- rangle bv J. R. Ball. STRATIGRAPHIC SUMMARY 13 4. Shaw Point 3. Macoupin 2. Burroughs 1. Shoal Creek (Carlinville) In Jasper and Cumberland counties of southeastern Illinois several cyclo- thems are well exposed as follows : 5. Woodbury 4. Gila 3. Greenup 2. Newton 1. Bogota Reconnaissance field studies in south central Illinois by Sidney E. Ekblaw resulted in the tentative recognition of the following- cyclothems : 6. Shumway 5. Shelby 4. Omega 3. Effingham 2. Divide I. LaSalle Subsequent attempts to fuse these ob- servations into a single standard section based upon the assumption that the Omega and Greenup limestones are equivalent resulted in the following series of cyclothems : 13. Shumway 12. Woodbury II. Gila 10. Greenup or Omega 9. Newton 8. Upper Bogota 7. Lower Bogota 6. Colin 5. Upper Livingston 4. Lower Livingston 3. Macoupin 2. Flannigan 1. Shoal Creek If the Greenup and Omega, however ? are not equivalent, a different arrange- ment is necessary. Without proposing new names (some of the following names are field terms that have not been pub- lished previously) approximately the following section occurs : 14. Woodbury 13. Gila 12. Greenup 11. Shumway or Newton 10. Shelby 9. Omega 8. Effingham 7. "Divide" 6. Cohn 5. Upper Livingston | 4. Lower Livingston ] 3. Macoupin 2. "Flannigan" or Burroughs or LaSalle or Shaw Point 1. Shoal Creek In the above list Flannigan and Di- vide are placed within quotations be- cause the true positions of the beds at the type localities are not certainly known with reference to any others. The name Bogota is not used here because the type Bogota probably closely under- lies the Newton but has been used prin- cipally for beds closely overlying the Cohn. Aside from differentiation of the Omega and Greenup limestones, the principal difference of this last section is in the position of the Shumway cyclo- them and its possible equivalence to the Newton. If this sequence is correct or nearly so it is probably incomplete, and other cyclothems may occur both above and below the Omega. One other diffi- culty is encountered in this arrangement because the Shelbyville coal, which ac- cording to Sidney E. Ekblaw is a part of the Shelby cyclothem, was assigned to the Newton cyclothem by W. A. New- ton (1941, p. 7), who believed that it occurred beneath the Omega in Shelby County. These as well as other matters await further clarification. Livingston limestone. — The Livings- ton limestone of eastern Illinois consists of two benches with intervening beds which thicken southward, and they ob- viously belong to two different cyclo- thems. On the basis of similar strati- graphic position, lithology, and faunas, they have been tentatively correlated with the LaSalle limestone of the north- ern part of the State. On the west side of the basin, similar limestones near Ramsey in Fayette County, Millersville in Christian County, Litchfield in Mont- gomery County, and Carlinville in Ma- coupin County have also been correlated with the LaSalle. It is entirely possible, however, that these western occurrences are representatives of two different zones 14 PENNSYLVANIAN OSTRACODES more widely spaced than the Livingston limestones of the east. These or similar beds have not been recognized south of Fayette and Crawford Counties. Little Vermilion limestone. — This bed is a member of a cyclothem that overlies the LaSalle c} T clothem of northern Illi- nois. It has never been correlated with any stratum farther south, and if the LaSalle limestone is equivalent to the Lower Livingston, it may or may not be representative of the Upper Livingston. Omega limestone. — This is a promi- nently outcropping bed in parts of Clay and Effingham counties, but is not cer- tainly known elsewhere. It may be ex- posed near Fairfield in Wayne County, and it may be equivalent to the Calhoun limestone of Richland County. If the Omega is older than the Greenup, the former has not been recognized on the east side of the basin except possibly near Calhoun. Shumway and Newton. — These two cyclothems of Effingham and Jasper counties respectively may be equivalent if the Greenup limestone is younger than the Omega. In spite of their occurrence in neighboring areas, however, there seem to be some significant differences both in physical character and strati- graphic association. The foregoing suggests some of the problems of Pennsylvanian stratigraphy and correlation in Illinois that remain unsolved. The following report suggests conclusions for some of them and may serve as the foundation for more detailed and specialized studies aimed at the so- lution of others. STRATIGRAPHIC DISTRIBUTION The Pennsylvanian strata of the East- ern Interior basin appear to include rep- resentatives of all epochs between the Chester and the Permian. The sedi- ments are intermediate in character be- tween those of the Appalachian pro- vince, where they are dominantly clastic with few limestones and other marine beds, and those of the Midcontinent region where marine limestones and shales dominate, with relatively few elastics. Pennsylvanian strata, particularly in Illinois, are commonly arranged in a regular lithologic sequence of beds as follows (Weller, 1930) : 10. Shale, gray, with ironstone concre- tions 9. Limestone, with marine fossils 8. Shale, black, hard, sheety, with large limestone concretions 7. Limestone, with marine fossils 6. Shale, gray 5. Coal 4. Underclay 3. Limestone, "fresh-water" 2. Shale or sandy shale 1. SaDdstone, unconformity at base The above sequence, the cyclothem, is seldom completely developed at any one place; however, beds 1, 4, 5, 9, and 10 commonly occur. Many cyclothems are characterized by the presence or absence of certain members, and many refine- ments of the current subdivisions of the Pennsylvanian system in Illinois have been worked out on the basis of cyclo- thems (Weller, 1931; Wanless, 1931, 1939). Ostracodes commonly occur in the up- per or marine members of the cyclo- thems, and the collections made are, for the most part, from calcareous shales above and below the marine limestones. In the references to the occurrence of ostracodes which follow, the species are referred to "zones," preceded by the name of the formation or cyclothem from which they were collected. A considerable number of Illinois cyclothems have been correlated with the Middle Pennsylvanian strata of the Midcontinent region and many can be traced directly into beds of the Des Moines and Missouri series in the neigh- boring states of Iowa and Missouri. Be- low the Des Moines series, sediments are thick, dominantly clastic, with few min- able coals and marine strata, and are difficult to correlate in detail. A correla- tion of Pennsylvanian formations of the Eastern Interior basin has been com- piled by Moore, et al. (1944). Because the Illinois Pennsylvanian section is closely comparable to that of the Midcontinent through the tracing of a number of horizons from Iowa into western Illinois, the subdivisions of the latter classification are used in age desig- nations (p. 16). The desirability of this arrangement is emphasized by the fact that most of the previously de- scribed species of Pennsylvanian ostra- codes are from formations of the Mid- continent area. The group names now used in Illinois were first used as formational units, ar- bitrarily drawn at certain coal or other distinctive horizons. Later some of these divisions were found to lie within cyclo- thems, and inasmuch as the breaks pre- ferably should occur at the base, this po- sition has since been changed. There- fore the Caseyville-Tradewater contact falls below the Willis coal and the Tradewater-Carbondale break occurs at the base of the Lower Liverpool cyclo- them, below coal No. 2. The Carbondale- McLeansboro contact is still drawn at the base of the Sparland cyclothem, above coal No. 6 and the Brereton cyclo- them. However, the series of the Penn- sylvanian in the Midcontinent area have been defined largely on faunal criteria, which has been used to evaluate the sig- nificance of unconformities within the [15] 16 PENNSYLVANIA^ OSTRACODES MIDCONTINENT d Z □ I a. C a L L 1 N O 1 S SOUTHERN INDIANA WESTERN KENTUCKY is, O Iowa, Mo., Kan., Okla., Texas WESTERN NORTHERN CENTRAL SOUTHERN Z < < Lower Admire 28 as o Z < L. Vermilion eye. Woodbury Is. Gila Is. Greenup Is. Shumway eye. Omega Is. Bogota eye. Cohn eye. Newton Is. Bogota eye. Emporia V.' c- 27 Burlinqame Scranton Howard Severy Topeka ■- on > i < Cc -:.- Deer Creek ■-" Tecumseh Lecompton 5 Seaborne 4 Munterville Frensley 3 Seville Is. Rock Island c. Bernadotte ss. Pope Creek c. Tarter c. Babylon ss. Curlew Is. Murphysboro c. Murray Bluff ss. Delwood c. Boskydell ss. Willis c. Pounds ss. Battery Rock c. Sellers Is. Battery Rock ss. Lusk ss. Minshall Is. Minshall c. U. Block c. L. Block c. Ferdinand Is. Fulda Is. Cannelton c. Mansfield ss. Hindostan ss. Curlew Is. Mannington c. Aberdeen ss. Ice House c. Bell c. U. Caseyville cgl. L. Caseyville cgl. >- LU < ; < Lester < 5 : r ■■• ' : ■> 2 > >■ < > "S Wapanucka 1 c -a o 5j Limestone Gap ml D X Union Valley Fig. 2 — Table showing relative stratigraphic positions of beds from which ostracodes were collected. Except for beds of Des Moines and lower Missouri age, correla- tions with the Midcontinent are approximate and tentative. STRATIGRAPHIC DISTRIBUTION 17 system (Moore, 1944, p. 667). The Mor- row is designated the zone of Hustedia miseri, the Atoka the Mesolobus striatus zone, the DesMoines the Mesolobus meso- lobus zone, the Missouri the Chonetina zone, and the Virgil the Chonetes trans- ver sails zone. On the basis of the fusu- lines the Des Moines is sharply denned as the zone of Fusulina, while the Fusu- linella zone occurs below and the zone of Triticites is found above, in the Missouri and Virgil series. For these reasons the outline of the following discussion of the stratigraphic distribution of the ostracode faunas fol- lows the series and group classification of the Midcontinent, using the forma- tions and cyclothem names applied to the Illinois Pennsylvanian. It is not to be construed that the group names in Illinois are to be replaced by those of the Midcontinent, but it is felt that, because of the faunal basis of the latter classification, it lends itself more readily to a description of the occurrence of the ostracodes. The group names in current use by this Survey are shown on the chart of formations (fig. 2, p. 16) and on the faunal chart (in pocket). The samples studied yielded some 300 species classified into 47 genera and 15 families (see faunal chart). Of the os- tracodes recognized in the Pennsylvan- ian system in Illinois, by far the largest number of species (95) are referrable to the Bairdiidae (8 genera) followed by the Kirkbyidae (40 species in 9 genera) ; Healdiidae (33 species in 3 genera) ; Kloedenellidae (32 species in 8 genera) ; Cytherellidae (27 species in 3 genera) ; Hollinellidae (21 species, all Hollin- ella) ; Leperdititellidae (17 species in 5 genera) ; and Cypridae (12 species in 3 genera). All other families are repre- sented by a single genus. with from one to seven species. The genus Bairdia possesses the larg- est numbers of identified species (41), followed by Healdia (29), Cavellina (22), Hollinella (21), Coryellites (17), and Amphissites (12). All other genera are represented by not more than 9 species each. Three new genera — Fabalicypris, Hastifaba, and Paraparchitella — are de- scribed in this report, and a total of 109 new species is included in the 300 species described and figured. A number of previously described species, based largely on immature specimens, have been eliminated by placing them in the synonomy of earlier described species. The following previously described genera are recognized in the Pennsyl- vanian for the first time : Darwinula, Lochriella, Microparaparchites, Propar- aparchites, and Sargentina, all known from the Mississippian, and Gutschickia from the Permian. A number of species, holdovers from the Mississippian or car- rying over into the Permian, are noted in the following discussion of the de- tailed stratigraphic distribution of the Pennsylvanian ostracodes. In the Upper Pennsylvanian, particu- larly in the upper Des Moines and younger strata, zones in the underclay limestones and associated beds yield distinctive "fresh-water" faunas. These usually contain a very large number of individuals but few species, there being- only 16 species known in five genera. Associated fossils are Spirorbis and plant spores; the typical marine species which usually occur in the limestones and shales above the coal are generally ab- sent. Sometimes typical marine forms sparingly occur in these beds. However, many marine forms can exist in environ- ments having a considerable variation m the degree of salinity so that their pres- ence does not necessarily indicate a truly marine deposit. Since fresh-water forms are unable to exist in saline water, their presence indicates a fresh-water deposit, unless it can be shown that the fresh- water species were transported from their native habitat. The Summum, Lonsdale, Bogota, and Newton zones contain 4 to 6 species each of the genera Candona, Carbonita, and Gutschickia. The other genera repre- 18 PENNSYLVANIAN OSTRACODES sented are Darwinula and Hastifdba. Other zones carrying two to four species each are the Seville, ' ' Centralia, " and Cohn. In the compilation of the graphs showing species distribution (figs. 3-32) these species have been omitted. An analysis of the faunal chart shows that most Pennsylvanian species are long ranging and that there are no sharp Virgil Pig. 3 — Graphic representation of the strati- graphic distribution of ostracode species in the Pennsylvanian strata of Illinois. The open portion of the columns shows the number of restricted species, the solid portion the number of species oc- curring in other zones. faunal breaks marking series or group boundaries, such as occur in the Chester series (Cooper, 1941, p. 8). In attempt- ing to make correlations, therefore, re- liance must be placed on the relatively few species that appear to be restricted to various zones (see fig. 3). It should be remembered, however, that new spe- cies listed as occurring in one zone only may be found by subsequent work to have a much greater stratigraphic range. Only five zones, however, namely in the Seahorne, Wiley, Craborchard, Banks- ton Fork, and Collinsville, were found to be lacking in apparently restricted species. TI VALLEY SERIES 1 Since there is no well established name in use for the oldest Pennsylvanian series of the Midcontinent, to which area the Illinois Caseyville and part of the Tradewater groups seem most closely allied, Ti Valley is used here to include all formations between the base of the Pennsylvanian system and the base of the Des Moines series. It appears that formations exposed in this valley in east- central Oklahoma, on the borderline be- tween the Arbuckle and Ouachita moun- tains, contain beds ranging in age from Morrow through Atoka. Morrow has been used by the U. S. Geological Sur- vey (Wilmarth, 1938, p. 1424) both as a series and as a group name, and by Moore (1944, chart) as a series name. It does not contain beds as young as Atoka. Lampasas (Cheney 1940. pp. 66, 82), used by Moore for the post-Morrow beds, apparently is not acceptable to the Texas Geological Survej^, probably be- cause these beds overlap the Des Moines boundary. Atoka seems to be gaining favor among stratigraphers working in that region for the formations between the Morrow and Des Moines. Probably the Stanley and Jackfork formations are older than Morrow and younger than the Chester of the Mississippi Valley and therefore do not form a part of the Ti lr This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. STRATIGRAPHIC DISTRIBUTION 19 Valley series (except possibly some of the Jackfork) . It is believed that future work will demonstrate the presence in the Appalachians and the Midcontinent of a post-Chester — pre-Morrow series, to which the names Pushmataha (in the west) and possibly Summers (in the east) can be applied. The latter is the name of the county in West Virginia where the upper Mauch Chunk forma- tions are well exposed. In Illinois the basal Pennsylvanian sandstones and shales, which rest un- conformable on Chester and older form- ations, are of Ti Valley age and contain zones up to and including the Seville (Curlew) cyclothem. Included are three zones from which ostracodes have been obtained — the Fulda (Morrow) and the Ferdinand and Seville (Atoka). The ostracodes restricted to the series (but not to groups or zones) are Ectodemites harlioni Cooper, n. sp., and Kirkbya bendensis Harlton. The boundary be- tween the Caseyville and Tradewater groups occurs in this series, below the Willis coal. Morrow Group 2 The Morrow ostracode fauna is char- acterized by a predominance of the Kirkbyiidae with which are classified 10 of the 12 species from the Fulda forma- tion. Li.i . Ti Val. Des Moines Missoui Fig. 4 — Histogram showing the number of ostracode species in the Fulda zone, and their distribution in other Pennsyl- vanian zones of the Illinois basin. (Hori- zon 1 of fig. 2 and faunal chart). NOTE: In this and succeeding figures (5-31 inclusive), the total number of species is represented by the total length of the combined open and solid column, the open portion represents the number of species restricted to this horizon, and the solid portion shows the number of species occurring in other formations. Ti Val. = Ti Valley series (Morrow and Atoka groups). Fulda limestone. — Only one f ossifer- ous zone of Morrow age, the Fulda lime- stone and associated beds (Franklin, 1944) of Spencer County, Indiana, is known to contain ostracodes, although one other fossilferous zone, the Sellers limestone, is known in Illinois. A good index of the Fulda, Polytylites wapa- nuckensis (Harlton), was described from the Wapanucka limestone of Okla- homa. Of interest is the occurrence of two upper Chester species, Kirkbya reflexa Girty and Kirkbyella cf. K. gut- kei Croneis and Bristol. The only other restricted species is Monoceratina ard- morensis (Harlton). The total absence of Healdia is noteworthy. Figure 4 shows that whereas a number of the Morrow species occur in the Des Moines few are found in younger formations. Atoka Group 3 Two zones of Atoka age, the Ferdinand limestone and the Seville cyclothem, in the Eastern Interior basin contain micro- fossils. The former yielded only 11 spe- cies, but the latter contains 46 species, 5 of which are common to the two zones. These are Bairdia dissimilis Cooper, n. sp., Bairdia pennata Coryell and Sam- ple, Fabalicypris regidaris Cooper, n< sp., Fabalicypris wileyi Cooper, n. sp., and Kirkbya magna Roth. Only two species appear to be restricted to the group, Bairdia dissimilis and Fabali- cypris regidaris, both new. The larger fauna of the upper zone contains a greater variety of genera, as might be expected, but it is composed largely of Bairdiidae and Kirkbyidae. Val. Des Moine Virgil Fig. 5 — Distribution of ostracode species oc- curring in the Ferdinand zone (horizon 2). -••'This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. 20 PENNSYLVANIAN OSTRACODES Ferdinand limestone. — Like the Mor- row, the beds of Atoka age contain few fossiliferous marine zones in this area, the Ferdinand and Seville limestones and the Boskydell sandstone, the last of which is without identifiable ostracodes. The lowest zone, or Ferdinand, occurs above the Fulda limestone in Spencer County, Indiana (Franklin, 1944). The following species are known in the East- ern Interior basin only in this forma- tion : Bairdia ardmorensis Harlton and Ectodemites plummeri Cooper, n. sp. The last is common in the lower Marble Falls of Texas. The absence of Healdia in this formation is also noteworthy. Figure 5 shows that, although a number of Ferdinand species persist through the Des Moines and a few continue into the younger Missouri and Virgil series, most of the species are restricted to the Ti Valley and to the lower part of the Des Moines series. Seville zone. — The highest ostracode- bearing beds of Atoka age occur in the Seville cvclothem of western Illinois, Ti Val. Des Moine-i Missouri Vinril Fig. 6 — Distribution of ostracode species oc- curring in the Seville and Curlew zones (horizon 3). The species restricted to this zone, given in the following list, represent 30 per- cent of the total number found. *Bairdia angusta Cooper, n. sp. Bairdia harltoni Cooper, n. sp. Bairdia schaurothiana Kirby Carbonita orbiculata Cooper, n. sp. *Cyathus striatus Cooper, n. sp. Fabalicyp?'is tenuis Cooper, n. sp. Healdia fabalis Cooper, n. sp. *Healdia longula Cooper, n. sp. Jonesina biformis Bradfield Microcheilinella minuta Cooper, n. sp. Paraparchitella erata Cooper, n. sp. Paraparchites claytonensis Knight Paraparchites semicircular is Cooper, n. sp. Silenites asymmetrica Cooper n. sp. The range of unrestricted species is found to cover most of the other Penn- sylvanian horizons. Correlation is also possible when two or more species are present in a zone, some beginning there and ranging up- ward, others ranging downward from this stratigraphic level. The presence of any two opposite ranging forms serves as an index. The following are such species which occur in the Seville, the direction of the range indicated by the arrow: (J,) down from the Seville, (f) up from the Seville, f Amphis sites centronotus (Ulrich and Bassler) f Amphissites girtyi Knight | Ardmorea gibberosa (Knight) 1 Basslerella firma Kellett | Bairdia altifrons Knight f Bairdia loliitesidei Bradfield f Coryellites firma Kellett | Goryellites palopintoensis (Coryell and Sample) ^Coryellites pediformis (Knight) i Ectodemites harltoni Cooper, n. sp. f Fabalicypris minuta Cooper, n. sp. IFabalicypris regularis Cooper, n. sp. 1 Healdia boggyensis Harlton | Healdia elegens Warthin | Healdia glennensis Harlton i Kirkbya bendensis Harlton f Kirkbya inornata Roth f Moorites knighti? (Wilson) ^Moorites minutus (Warthin) ^Moorites specij 'erus (Wilson) ^ Moorites ivapanuckensis (Harlton) | Paraparchites exiguus Cooper, n. sp. | Sulcella sulcata Coryell and Sample | Waylandella vulgaris Cooper, n. sp. "Asterisks denote easily recognized forms that are probably good horizon markers. STRATIGRAPHIC DISTRIBUTION 21 DES MOINES SERIES 4 Thirteen of the 29 ostracode-bearing zones of Illinois are of Des Moines age, which corresponds to the upper Trade- water, Carbondale, and lower McLeans- boro groups. The number of species in a single zone ranges from 5 to 66 ; the variability of the faunas is much greater than in the Morrow. Most of the Penn- sylvanian genera are represented in the Des Moines, exceptions being Caroonita, Cyathus, Glyptopleura, Kirhoyella,Kloe- denella, Polytylites, Sargentina, and Seminolites. Ardmorea, Microparapar- chites, and Waylandella are not known from beds younger than the Des Moines. Restricted to the series, but not to any particular group or zone, are the follow- ing species : Amphissites transversus Roth Coryellites parallela (Knight) Coryellites simillima (Bradfield) Coryellites tomlinsonella Cooper, n. sp. Healdia carterensis Bradfield Healdia spinosa Cooper, n. sp. Hollinella kellettae Knight Macrocypris menardensis Harlton Macrocypris teretis Cooper, n. sp. Microparaparchites elongatus Cooper, n. sp. Microparaparchites ovatus Cooper, n. sp. Microparaparchites wapanuckensis ( Harlton ) Silenites fabalis Cooper, n. sp. Waylandella bythocyproidea (Warthin) Waylandella dispar Cooper, n. sp. Waylandella obesa Cooper, n. sp. Cherokee Group 5 The following species are not known to occur outside of this lower DesMoines group : Cavellina equalisf Coryell Coryellites lowelli Cooper, n. sp. Healdia marginata Harlton Hollinella minuta Cooper, n. sp. Waylandella regularis Cooper, n. sp. Seahorne zone. — The Seahorne fauna contains 24 species, predominantly Am- phissites and Healdia. No species re- stricted to the Seahorne were found. Figure 7 shows the distribution of the species of this zone to be primarily in beds of lower Des Moines age. The opposite-ranging forms in the Seahorne are : ^Amphissites centronotus elongatus Payne | Amphissites roundyi Knight | Amphissites transversus Roth i Fabalicypris minuta Cooper, n. sp. f Healdia granosa Cooper, n. sp. f Healdia marginata Harlton f Healdia oblonga Bradfield | Hollinella minuta Cooper, n. sp. | Kellettina montosa (Knight) \Kirkbya inornata Roth ^Waylandella bythocyproidea (Warthin) f Waylandella regularis Cooper, n. sp. Wiley zone. — None of the 15 species of the Wiley fauna is known to be restrict- ed. The distribution of species as is shown in figure 8, is mostly among beds of lower Des Moines age. The opposite-ranging forms in the Wiley are as follows: ^Coryellites centralis (Coryell and Billings) | Coryellites tomlinsonella Cooper, n. sp. | Healdia spinosa Cooper, n. sp. j Microparaparchites wapanuckensis (Harlton) f Roundyella simplicissima (Knight) I Waylandella vulgaris Cooper, n. sp. Ti Val. Des Moines Missouri Virgil Fig. 7 — Distribution of ostracode species oc- curring in the Seahorne zone (horizon 4). Ti Val. Des Moines Missouri Virgil Fig. 8 — Distribution of ostracode species oc- _j2urring in the Wiley zone (horizon 5). *- B This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinen't region. 22 PENNSYLVANIAN OSTRACODES Liverpool (Oak Grove)zone. — This zone is one of the most fossiliferous in the Des Moines series, 64 species having been recognized from it. Of these, 77 percent occur in other zones. It contains an un- usual number of species of Coryellites, no less than 9 of the 17 Pennsylvanian species being present. The list of ap- parently restricted species follows. Cavellina bisecta Bradfleld Cavellina fittsi Kellett *Coryellites cooki (Bradfleld) Ti Val. Des Moines Missouri Fig. 9 — Distribution of ostracode species oc- curring in the Oak Grove beds (horizon 6). *Fabalicyi)ris acuminata Cooper, n. sp. Fabalicypris dispar Cooper, n. sp. Fabalicypris plana Cooper, n. sp. *Healdiacypris acuminatus Cooper, n. sp. Knightina allerismoides (Knight) Knightina kellettae Bradfleld Microparaparchites cornutus Cooper, n. sp. Sansabella amplectans Roundy Sansabella exilis Cooper, n. sp. Sansabella laevis (Warthin) Waylandella symmetrica Cooper, n. sp. Although known only in the Oak Grove in Illinois, Cavellina oisecta Brad- field and Sansdbella amplectans Roundy are known from older strata in Okla- homa and Texas. Likewise Knightina allerismoides (Knight) occurs somewhat higher in the Fort Scott beds of Mis- souri and Coryellites cooki (Bradfleld) occurs in strata of Liverpool age in the Ardmore basin. Cavellina fittsi Kellett was reported from the lower Virgil in Kansas; C. casei Bradfleld, believed to be conspecific with Kellett 's C. fittsi, was reported from the Otterville and Jolliff in the Ardmore basin. The distribution of unrestricted species is largely con- fined to the Des Moines, although several are present in the Ti Valley (fig. 9). The opposite-ranging forms in this zone are : 4, Amphissites alticostatus Bradfleld | Bairdia menardensis Harlton I Bairdia pennata Coryell and Sample | Bairdia peracuta Warthin | Cavellina angusta Cooper, n. sp. | Cavellina equalis? Coryell | Cavellina lata Coryell | Cavellina pulchella Coryell f Coryellites elongata Coryell f Coryellites lowelli Cooper, n. sp. | Coryellites parallela (Knight) | Coryellites simillima (Bradfleld) ^Coryellites subelliptica (Upson) f Ellipsella bradfieldi Cooper, n. sp. I Healdia boggyensis Harlton | Healdia carterensis Bradfleld i Healdia marginata Harlton f Hollinella kellettae Knight I Hollinella minuta Cooper, n. sp. f Microparaparchites elongatus Cooper, n. sp. ^Microparaparchites ovatus Cooper, n. sp. | Moorites punctus (Wilson) | Silenites fabalis Cooper, n. sp. f Waylandella dispar Cooper, n. sp. | Waylandella obesa Cooper, n. sp. I Waylandella regularis Cooper, n. sp. STRATIGRAPHIC DISTRIBUTION 28 Marmaton Group 6 Among the ostracode-bearing zones of this group, extending from the Hanover to the Exline limestone inclusive, are some of the best known fossilliferous zones of the entire Pennsylvanian sys- tem, which are associated with the most extensively mined coal beds in the East- ern Interior basin, numbers 5 to 7 in- clusive. Species apparently restricted to the Marmaton are as follows : Bairdia crassa Harlton Bairdia menardvillensis Harlton Coryellites contracta Cooper, n. sp. Geisina gregaria Ulrich and Bassler Geisina wartMni Cooper, n. sp. Healdia rectis Cooper, n. sp. Hollinella levis Cooper, n. sp. Microparaparchites brazoensis (Coryell and Sample) Silenites lenticularis Knight Summum (Hanover) zone. — This zone contains two species of the genus Gut- schickia heretofore recognized only in the Permian, where it occurs in a' 'fresh- water" environment. Associated with Ti Val. Des Moines Missouri Virgil Fig. 10 — Distribution of ostracode species oc- curring in the Hanover zone (horizon 7). 6 This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. these are species of Candona, Darwin- ula, and Hastifaba. Of the two previ- ously described species from this zone, Healdiacypris perplexa Bradfield occurs in beds of equivalent age in the Ardmore basin. The presence of only one species each of the usually prolific genera of Bairdia and Cavellina is somewhat ab- normal. A complete list of apparently restricted species follows. Most of the unrestricted species occur in nearby horizons (see fig. 10). Candona planidorsata Cooper, n. sp. *Darwinula pungens (Jones and Kirkby) Gutschickia levis Cooper, n. sp. Gutschickia ovata Cooper, n. sp. *Hastifaba robusta Cooper, n. sp. Healdiacypris perplexa Bradfield Microparaparchites angustus Cooper, n. sp. The opposite ranging species are : 4, Amphissites transversus Roth f Bairdia coryelli Roth and Skinner 1 Candona salteriana (Jones and Kirkby) i Cavellina equalis? Coryell ^Cornigella tuberculospinosa (Jones and Kirkby) | Coryellites contracta Cooper, n. sp. i Coryellites lowelli Cooper, n. sp. I Coryellites tomlinsonella Cooper, n. sp. i Fabalicypris wileyensis Cooper, n. sp. | Geisina warthini Cooper, n. sp. f Healdia limacoidea Knight i Healdia nucleolata Knight f Healdia rectis Cooper, n. sp. I Moorites spiciferus (Wilson) | Sansabella whitei Bradfield j Waylandella dispar Cooper, n. sp. St. David zone. — Only one species of Healdia, a genus rarely providing good index forms, appears to be restricted to this zone, H. asper Cooper, n. sp. The occurrence of one species of Bairdia and none of Cavellina corresponds closely to a similar scarcity of these genera in the zone below, and as in the Summum, most of the unrestricted species occur in asso- ciated zones. The species ranging up and down from the St. David are : \ Bairdiacypris nebraskensis (Upson) 1 Coryellites contracta Cooper, n. sp. f Coryellites ovata Cooper, n. sp. i Healdia carterensis Bradfield I Healdia granosa Cooper, n. sp. I Healdia rectis Cooper, n. sp. I Hollinella kellettae Knight | Macrocypris teretis Cooper, n. sp. 24 PENNSYLTAXIAX OSTRACODES Ti Val. Des Moines Missouri Virgil Fig. 11 — Distribution of ostracode species oc- curring in the St. David zone (horizon S). Des Moines Missouri Virgil Fig. 12 — Distribution of ostracode species oc- curring in the Crabor chard zone (hori- zon 9). Ti Val. Des Moines Missouri Virg Fig. 13 — Distribution of ostracode species oc- curring in the Brereton zone (horizon 10). 4 Microparaparchites ovatus Cooper, n. sp. I Silenites fabalis Cooper, n. sp. | Silenites lenticularis (Knight) | Waylandella obesa Cooper, n. sp. Crdborchard zone. — Xo restricted spe- cies were found among the five known to occur in this zone which range through- out the Pennsylvanian section. No spe- cies of Bairdia or Healdia occur. Brereton (Herrin) zone. — The cyclo- them containing the extensively mined Xo. 6 coal carries a total of 31 species, 8 of which are restricted in their occur- rence. Most of the well known genera are represented. However, onh^ one species of Cavellina was recognized, C. rotunda Cooper, n. sp. The restricted species are as follows : * Bairdia citriformis Knight *Geisina gallowayi (Bradfield) * Hollinella elongata Cooper, n. sp. Hollinella pulchra (Moore) Jonesina dubia Bradfield Microcheilinella quadrata Cooper, n. sp. Microparaparchites quadratus Cooper, n. sp. Waylandella ardmorensis (Bradfield) Of these species Geisina gallowayi (Bradfield), Jonesina dubia Bradfield, and Bairdia citriformis Knight occur in correlative horizons in Oklahoma and Missouri. The last named species from the socalled Pawnee (probably Wor- land) in Missouri, has been reported by Bradfield from a much lower horizon in the Dornick Hills group. Hollinella pulchra (Moore) and Microparapar- chites quadratus Cooper, n. sp., are known to occur in younger formations, the South Bend and East Mountain formations respectively of Texas. The unrestricted species have a uniform dis- tribution. Species ranging up and down from the Brereton are : ^Bairdia beedei Ulrich and Bassler '[Bairdia crassa Harlton | Bairdia hoxbarensis Harlton | Bairdia monstrabilis Cooper, n. sp. i Bairdia ichitesidei Bradfield I Bairdiacypris trojana (Wilson) f Cavellina rotunda Cooper, n. sp. i Ellipsella bradfieldi Cooper n. sp. f Geisina gregaria (Ulrich and Bassler) i Healdia glennensis Harlton | Healdia oklahomacnsis Harlton STRATIGRAPHIC DISTRIBUTION 25 I Hollinella levis Cooper, n. sp. | Hollinella warthini Cooper, n. sp. I Kirkbya magna Roth f Macrocypris menardensis Harlton ^Moorites elongatus (Jones and Kirkby) Jamestown zone. — No less than 13 genera are represented in the fauna of 18 species found in this zone. Coryel- lites and Geisina have 3 species each and the others have one or two. Only two species of this moderately large ostra- code fauna appear to be restricted. These are Geisina jolliffiana and *Hastifaba pervulgata, both new species; the latter occurs in the Dornick Hills group of Oklahoma. The unrestricted species have about equal distribution in the Des Moines, Missouri and Virgil forma- tions. Ti Val. Des Moines Missouri Virgil Fig. 14 — Distribution of ostracode species oc- curring in the Jamestown zone (horizon 11). All except one of the opposite-ranging species of the Jamestown range down- ward, showing its close affinity with the Brereton. The list follows : iCoryellites parallela (Knight) i Geisina gregaria (Ulrich and Bassler) i Geisina warthini Cooper, n. sp. IHeaMia elegens Warthin I Hollinella dentata Coryell f Kirkbya firma Kellett I Macrocypris teretis Cooper, n. sp. Bankston Fork zone. — There are no restricted species known from this zone ; most of the fauna consists of species of Bairdia and Amphissites and it is uni- formly distributed throughout the Penn- sylvanian. Piasa-Sparland zone. — The only ap- parently restricted form from a fauna totaling 26 species is Waylandella cuy- leri Coryell and Booth, originally de- scribed from the Wayland shale in Ti Val. Des Moines Missouri Virgil Fig. 15 — Distribution of ostracode species occurring in the Bankston Fork zone (horizon 12). Texas, which is considerably higher stratigraphically than the Piasa-Spar- land zone. As usual in the Des Moines a large part of this fauna is made up of species of Amphissites, Bairdia, and Coreyllites, which account for nearly half of the species distributed among 13 genera. However, only one species of Cavellina is known. The unrestricted species show sporadic (i highs" in two zones of each of the upper three series with 10 to 15 species in each as shown in figure 16. Species ranging up and down from the Piasa-Sparland are : I Cavellina lata Coryell I Coryellites elongata Cooper n. sp. iCoryellites simillima (Bradfield) ^Coryellites texensis (Coryell and Sample) | Hollinella limata (Moore) | Hollinella oklahomaensis (Harlton) f Microparaparchites brazoensis (Coryell and Sample) i Microparaparchites elongatus Cooper, n. sp. i Microparaparchites wapanuckaensis (Harlton) i Silenites lenticularis (Knight) Ti Val. Des Moines Missouri Virgil Fig. 16 — Distribution of ostracode species oc- curring in the Piasa and Cutler (Spar land) zones (horizon 13). 26 PENNSYLVANIA!! OSTRACODES Lonsdale (Gimlet) zone. — The largest number of species (66) in any zone of the Des Moines and next to the largest number found in any Pennsylvanian zone in Illinois is associated with the Lonsdale limestone. Although 26 genera are represented, about half of the species belong to Basslerella, Bairdia. Coreyel- lites, Healdia, and HolUnella. The un- usually large number of species of Bass- lerella is noteworthy. Thirty-two percent of the species are restricted. Thev are as follows: i'i V;il. Dos Moines Missouri Virgil Fig. 17— Distribution of ostracode species oc- curring in the Lonsdale (Gimlet) zone (horizon 14). Basslerella obesa Kellett Basslerella.'' parallela Cooper, n. sp. Basslerella rostrata (Knight) Bairdiacypris sliideleri (Delo) *Carbonita agues (Jones) Cavellina cavellinoides (Bradfield) Cavellina expansa Bradfield Cavellina lintris Coryell and Sample Discoidella convexdt Scott and Borger Healdia usitata Cooper, n. sp. *Hollinella noicataensis Coryell and Osorio *Jonesina deesensis Bradfield Macrocypns garrisonensis Upson *MicroparapcurcMtes cuneatus (Warthin) Monoceratina leicisi Harris and Lalicker Monoceratina macoupini Scott and Borger Paraparcliites dispar Cooper n. sp. Paraparehites fabula Cooper, n. sp. * Proparaparchites parallelus Cooper, n. sp. Species in the above list, Cavellina cavellinoides (Bradfield), C. lintris Cor- yell and Sample. HolUnella nowataensis Coryell and Osorio, Jonesina deesensis Bradfield. and Micro paraparchites cune- atus (Warthin) occur in formations of similar age in Oklahoma and Texas. The following previously described species have been reported from higher forma- tions : — Basslerella obesa Kellett, Cavel- lina expansa Bradfield. Discoidella con- vexaf Scott and Borger. Kirkbya per- grandis Kellett. Kirkbyella hextensis (Harlton.), Macrocypris garrisonensis Upson, Monoceratina lewisi Harris and Lalicker and Monoceratina macoupini Scott and Borger. Basslerella rostrata (Knight) occurs in a lower zone, the so- called Pawnee limestone (probably "Wor- land) of Missouri. The large number of unrestricted species are distributed about equally among other zones. The species from the Lonsdale (Gim- let) zone are approximately equally di- vided between those ranging into higher and lower zones ; they are : f Amphissites robustus Cooper, n. sp. I Ardmorea gibberosa (Knight) f Basslerella acuminata Cooper, n. sp. I Basslerella fir ma Kellett 1 Basslerella lacrimosa Cooper, n. sp. i Bairdia erassa Harlton i Bairdia menardensis Harlton | Bairdia menardrillensis Harlton I Bairdia peracuta Warthin | Bairdiacypris acuminata Bradfield j Bythocypris subpediformis Bradfield t Coryellites scotti Cooper n. sp. STRATIGRAPHIC DISTRIBUTION <\ Ellipsella calcar (Harlton) f Glyptopleura coryelli Harlton ^Healdia cincta Coryell and Billings IHealdia limacoidea Knight IHealdia oblonga Bradfield | Healdia spinosa Cooper, n. sp. | Hollinella grandis Cooper n. sp. i Hollinella levis Cooper, n. sp. | Hollinella regularis Coryell | Jonesina subquadrata? Delo I Kellettina robusta? (Kellett) i Macrocypris menardensis Harlton XMoorites punctus (Wilson) I Paraparchites exiguus Cooper n. sp. Ti Val. Des Moines Missouri Virgil Fig. 18 — Distribution of ostracode species oc- curring in the Exline zone (horizon 15). Exline zone. — This zone, the highest in the Des Moines series, contains a moderately large number of ostracode species of which an unusually high per- centage (34 percent) are restricted. The zone contains the usual preponderance of species in the more common genera, but the occurrence of 6 species of Cavel- lina is a marked increase over the num- ber found in lower formations and slightly more than in any higher forma- tion. The restricted species are *Bairdia regularis Cooper, n. sp. Cavellina daubeana (Bradfield) * Cavellina minuta Bradfield Healdia formosa Harlton Jonesina bradyana (Jones) .Jonesina trisulcataf Bradfield Lochriellaf angusta Cooper, n. sp. Sansabella sulcata? Roundy Cavellina jejuna Bradfield, Cavellina minuta Bradfield, Healdia formosa Harlton, and Jonesina trisulcataf Brad- field are species reported from strata of comparable age in Oklahoma and Texas. However, Cavellina daubeana (Brad- field), has been reported from higher formations. The species ranging up and down from the Exline are : f Bairdia ampla Reuss i Bairdia menardvillensis Harlton I Bairdiacypris nebraskensis (Upson) f Cavellina cummingsi Payne iCoryellites centralis (Coryell and Billings) f Coryellites johnsoni (Upson) f Healdia aspinosa Cooper, n. sp. | Healdia cara Bradfield f Healdia colonyi Coryell and Booth i Hollinella warthini Cooper, n. sp. I Microparaparchites brazoensis (Coryell and Sample) ^Moorites indentus Cooper, n. sp. MISSOURI SERIES 7 As indicated in the stratigraphic sum- mary the correlation of Illinois beds above the Shoal Creek limestone with those of the Midcontinent are uncertain and those indicated on the chart (fig. 2) are tentative and approximate, based on an analysis of the ostracode faunas that have been studied to date. The middle McLeansboro group is correlated with this series. Glyptopleura is the only genus occur- ring in the Missouri series which has not been recorded from lower Pennsylvan- ion horizons, although it reaches its greatest development in the Chester. It is represented by the easily recognized G. coryelli found in several upper Penn- sylvanian formations. Genera which do not occur above the Missouri series in Illinois are Fabalicypris and Parapar- chites. The only species other than those restricted to a group or zone in this series are Kirkbya arcuataf Roth and Sansabella carbonaria Cooper, n. sp. T This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. 28 PENNSYLVANIAN OSTRACODES Bronson Group 8 There are no species restricted to the group, other than those listed under its various zones. Trivoli zone. — As usual, species of a few common genera, namely Amphis- sites, Bairclia and Healdia, make up about half of the total fauna of this zone. Cavellina, Coryellites, and Hollinella are each represented by two species. Re- stricted species are as follows : *Bairdia symmetrica Cooper, n. sp. Healdia bicornis Cooper, n. sp. Paraparchites inornatus? (McCoy) The species ranging up and down from the Trivoli are : I Healdia aspinosa Cooper, n. sp. I Healdia cincta Coryell and Billings i Healdia colonyi Coryell and Booth f Hollinella shawnensis Kellett | Sansabella carbonaria Cooper, n. sp. | Sansabella ovale Cooper, n. sp. Ti Val. Des Moines Missouri Virgil Fig. 19 — Distribution of ostracode species oc- curring in the Trivoli and Turner zones (horizon 16). Collinsville zone. — There is nothing unusual about this small fauna which contains no restricted species. The un- restricted species are found principally in the Upper Des Moines and lower Mis- souri series. The following species range up and down from the Collinsville : I Amphissites centronotus elongatus Payne | Bairdia ciscoensis Harlton 1 «-^- *1^ Ti Val. Des Moines Missouri Virgil Fig. 20 — Distribution of ostracode species oc- curring in the Collinsville zone (horizon 17). ^Cavellina footei (Coryell and Booth) '[Cavellina tongia (Coryell and Sample) I Fabalicypris wetumkaensis Cooper, n. sp. IMoorites wapanuckensis (Harlton) Shoal Creek zone. — Nearly three- fourths of the 15 species from this zone belong to Amphissites and Bairdia. Only one species, Bairdia spinosa Cooper, n. sp., is restricted but it is so distinctive that it is very easily recognized and may be considered (with the usual caution) a good marker. No species of Cavellina or Healdia are present. Most of the un- restricted species occur above the Des Moines. The species ranging up and down from the Shoal Creek are : i Amphissites girtyi Knight I Bairdia coryelli Roth and Skinner | Bairdia hoxbarensis Harlton | Bairdia pompilioides Harlton | Hollinella cushmani Kellett ^ Kirkbya arcuataf Roth Kansas City Group 9 "Centralia" zone. — "Centralia" is a field term formerly used for certain beds a short distance above the Shoal Creek limestone. This name is now considered unsatisfactory, and the exact correlation Des Moines Missouri Virgil Fig. 21 — Distribution of ostracode species oc- curring in the Shoal Creek and Hicks zones (horizon 18). S! 'This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. STRATIGRAPHIC DISTRIBUTION 29 of beds referred to it, from which cer- tain collections were obtained, is not definitely known. They may actually represent more than one ostracode-bear- ing zone (see p. 16). Collections re- ferred to the "Centralia" have yielded 31 species, more than are known from any other identified zone in the Missouri series. This fauna is extremely varied, since 17 genera are represented, of which only three contain as many as three species each, namely Bairdia, Bythocy- pris, and Moorites. The following species are known to occur only in these collec- tions : Bairdia summa Coryell and Billings *Bairdiacypris deloi Bradfield Bythocypris disparilis Cooper, n. sp. Bythocypris quadrata Cooper, n. sp. Jonesina infrequens (Bradfield) *Microcheilinella Mcornuta Cooper n. sp. Sansabella bolliaformis (Ulrich and Bassler) * Sargentina tumida Cooper, n. sp. Bairdiacypris deloi Bradfield and Jonesina infrequens (Bradfield) occur in comparable beds in the Hoxbar group of Oklahoma and Bairdia summa Cor- yell and Billings is found considerably higher in the Wayland shale of Texas. Most of the unrestricted species are found in the Missouri and Virgil series. Species apparently ranging up and down from the ' ' Centralia ' ' are : I Amphissites roundyi Knight I Basslerella acuminata Cooper, n. sp. | Basslerella ovata Cooper, n. sp. i Cavellina rotunda Cooper, n. sp. f Discoidella lingulata Cooper, n. sp. | Macrocypris illinoiensis Scott and Borger Macoupin zone. — This fauna contains 14 genera, the species of which are well distributed, Bairdia containing four spe- cies and Coryellites three, the other 12 Ti Val. Des Moines Missouri Virgil Pig. 22 — Distribution of ostracode species oc- curring in the "Centralia" zone (horizon 39). Ti Val. Des Moines Missouri Virgil Fig. 23 — Distribution of ostracode species oc- curring in the Hall and Macoupin zones (horizon 20). having one to two species each. Although containing one of the larger ostracode faunas (26 species) in the Missouri series, only one, Healdia ehlersi Brad- field from a slightly lower horizon in Oklahoma is restricted to it. With a few exceptions the distribution of the unrestricted species is rather uniform from the Des Moines on. The following species range up and down from the Macoupin : i Amphissites robustus Cooper, n. sp. I Bairdia oklahomaensis Harlton | Healdia simplex Roundy i HolUnella grandis Cooper, n. sp. I Kellettina montosa (Knight) | Kirkbya punctata Kellett i Sansabella ivhitei Bradfield 30 PENNSYLYANIAN OSTRACODES Lansing Group 10 La Salle-Livingston-Miller sville zone. — In this fauna of 41 species, more than half are classed under Amphissites, Bairdia, Healdia, and Hollinella. Of the comparatively large numbers of spe- cies restricted to this zone, Hollinella raderlae (Harlton) with its three nodes is the most easily recognized. Although this species has a wide range in the Mid- continent, as now known it is restricted to this zone in Illinois. The species which occur only in this zone are as fol- lows ( S = LaSalle, M = Millersville, h = Livingston) : Amphissites adjunctio Cooper, n. sp. (L) *Amphissites congruens Cooper, n. sp. (L) * Bairdia hooverae Kellett (S) * Bairdia lunata Bradfield (M) Bairdiacypris haydenbranchensis (Payne) (M) Ectodemitis geneae (Roth) (M) Ectodemites sullivanensis (Payne) (M) Glytopleura irregularis (Delo) (M) Healdia alba Coryell and Billings (L) *Healdia carinata Cooper, n. sp. Healdia cf. H. obsolens Delo (S) * Hollinella radlerae (Harlton) (S) Knightina harltoni Kellett (M) The LaSalle is comparable to the Stan- ton of Kansas, which also contains Bairdia hooverae Kellett. The presence of this and several other species in the Hayden Branch beds of Indiana indi- cates that the latter also is correlative with this zone. Other restricted species, common to the Millersville and Hayden Branch, are Ectodemites sullivanensis (Payne), Bairdiacypris haydenbran- chensis (Payne) and Knightina harltoni (Kellett). Other species common to these two zones, but not restricted in the Illinois basin are Amphissites centrono- tus (Ulrich and Bassler) Bairdia beedei Ulrich and Bassler, B. pompilioides Harlton, and Cavellina symmetrica (Payne). The Livingston has Healdia simplex lloundy and Cavellina pulchella Coryell in common with the Hayden Branch. 10 This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. Bairdia lunata Bradfield was first identified from the Hoxbar group in the Ardmore basin of Oklahoma while Ecto- demites geneae (Roth) is known from the Fort Scott into the Permian. Ecto- demites sullivanensis (Payne), Bairdia- cypris haydenbranchensis (Payne), and Knightina harltoni Kellett were all de- scribed from lower zones. Glyptopleura irregularis Delo heretofore has been known only from the Permian. Ti Val. Des Moines Missouri Virgil Fig. 24 — Distribution of ostracode species oc- curring in the LaSalle, Livingston, and Millersville zones (horizon 21). A number of species are common to two of the three zones. Those in the LaSalle-Millersville are Amphissites cen- tronotus (Ulrich and Bassler) and Glyptopleura coryelli Harlton ; those in the LaSalle-Livingston are Bairdia monstrabilis Cooper, n. sp., Ectodemites dattonensis (Harlton), and Kirkbya punctata Kellett; and Bairdia seminalis Knight occurs in the Livingston-Millers- ville. The distribution of unrestricted species is quite uniform from middle Des Moines through the Virgil. STRATIGRAPHIC DISTRIBUTION 31 The following species range up and down from this zone. 4 Amphissites rothi Bradfield | Bairdia crassimarginata Cooper, n. sp. f Bairdia hurwitzi Coryell and Booth | Bairdiacypris ardua Cooper, n. sp. f Gavellina ovidiformis (Harlton) | Cavellina symmetrica (Payne) I Glyptopleura coryelli Harlton I Hollinella limata (Moore) I Kirkby a arcuata? Roth 4 Sansabella carbonaria Cooper, n. sp. VIRGIL SERIES 11 Although there are no significant breaks between beds of Missouri and Virgil age in Illinois the classification of the Midcontinent utilizing both of these terms is shown in the left column of the stratigraphic chart (fig. 2). This series is the equivalent of the upper McLeans- boro. Missouri uses only one series for the Upper Pennsylvanian formations above the Des Moines. Of the 33 genera represented in the Virgil, only one, Kloedenella, is not found in any of the lower Pennsylvanian series. The zones of this series contain increasing numbers of Permian species known largely from the Midcontinent region. Restricted species, other than those listed under the subordinate zones, are as follows : Amphissites carinatus Cooper, n. sp. Bairdia blakei Harlton Bairdia scholli Coryell and Booth Candona bairdioides (Jones and Kirkby) Carbonita inflata (Jones and Kirkby) Cavellina laevis (Bradfield) Cavellina subpulchella Coryell Gutschickia ninevehensis (Holland) Seminolites truncatus Coryell Douglas Group 12 No strata of Peedee age in Illinois are definitely recognized and beds next above the LaSalle or its equivalents may be of Douglas age. Colin zone. — The few species known from this zone have a distinctly "fresh- water" aspect. The only restricted spe- n - 12 This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois st.ata with those in the Midcontinent region. cies are Carbonita tenuis, *Hastifata spinosa, and Kloedenella carbonica, all new species. u Ti Val. Des Moines Missouri Virgil Fig. 25 — Distribution of ostracode species oc- curring in the Cohn zone (horizon 22). Bogota zone. — Of the 19 species found in the Bogota, 17 occur in other zones, The restricted species are Hollinella grahamensis (Harlton) and Microchei- linella inflata Kellett. Hollinella grahamensis (Harlton) oc- curs in slightly older beds in Oklahoma and Texas, and Microcheilinella inflata Kellett is known from both lower and higher beds in Kansas. The unrestricted species are found in various zones above the middle Des Moines. Species ranging up and down from the Bogota are : | Amphissites carinatus Cooper, n. sp. f Bairdia blakei Harlton i Candona salteriana (Jones and Kirkby) ^Carbonita inflata (Jones and Kirkby) ^Cavellina laevis (Bradfield) i Cavellina pulchella Coryell | Cavellina subpulchella Coryell | Hollinella crassimarginata Kellett iKirkbya kellettae Harlton | Seminolites truncatus Coryell Ti Val. Des Moines Missouri V Fig. 26 — Distribution of ostracode species oc- curring in the Bogota zone (horizon 23). 32 PENNSTLYAXIAX OSTRACODES Shawnee Group 13 Little Vermilion zone. — An unusually large number of genera (19) is repre- sented in this moderately large fauna of 30 species. The only genera represented by more than two species are Bairdia and Coryellites. This zone has the fol- lowing restricted species : Discoidella perminuta? (Kellett) Healdia mason i Coryell and Booth Knightina ampla Kellett *Microcheiiinella unispinosa Cooper, n. sp. *Monoceratina bradfieldi Cooper, n. sp. Sansabella brevis Cooper, n. sp. Sargentina elongata Cooper, n. sp. The presence of the Wayland and Deer Creek species. Healdia masoni Cor- yell and Bootli and Knightina ampla Kellett. indicate the Shawnee age of this zone, although the latter species has been reported from the Belle City, an older zone in Oklahoma. As in other Upper Pennsylvanian zones the unrestricted species find their greatest distribution above the middle Des Moines. Ti Val. Des Moine> Missouri Virgil Fig. 27 — Distribution of ostracode species oc- curring in the Little Vermilion zone I horizon 24). Species ranging up and down from the Little Vermilion are : f Bairdia scholli Coryell and Booth I Bythocypris subpediformis Bradfield iCavellina ovidiformis (Harlton) i Healdia oklahomaensis Harlton IJonesina subquadrata? Delo IKelletina robust a ? (Kellett) I Loeliriella elongata Cooper, n. sp. i Sansabella ovale Cooper, n. sp. Omega zone. — This small fauna con- tains one restricted species. Carbonita magna (Upson) . Io U Ti Val. Des Moines -i r — — 1 Missouri Virgil "This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. Fig. 28 — Distribution of ostracode species oc- curring in the Omega zone (horizon 25). Neioton-Shumway zone. — The largest fauna (68 species' 1 found in the Penn- sylvanian of Illinois occurs in this zone. This fauna comprises 23 genera, with unusually large numbers of Bairdia (18 species), Coryellites (9 species) and. Cavellina (7 species'), and Hollinella (8 species). Others well-represented are Healdia and Moorites with four species each. Of the total number of species about one-third come from the Newton, more than one-third from the Shumway. while less than one-fourth occur in both zones. The fauna is a mixture of marine and "fresh-water" types and probably indi- cates a brackish water habitat, although the possibility of the mixing of faunas by current transportation must be recog- nized. The "fresh-water'" genera rep- resented are Candona. Carbonita. and Ghitschickia, present in both the Xewton and Shumway. These make up a group of easily recognized forms which occur in or associated with underclay lime- stones. More than one-fourth of the species (28 percent) are restricted, as follows (N = Xewton. S = Shumway) : Basslerella ovata Cooper, n. sp. (X) Bairdia garrisonensis Upson (S) Bairdia kingii Reuss (X) Bairdia pinnula Coryell and Bocrh (S) "Bairdia cf. B. rhomlwidea Kirkby (S) Bairdia verwiebei Kellett (X, S) Cavellina Urata (Bradfield) (X) *Cavellina nebraseensis (Geinitz) (N) Coryellites mytilliformis (Bradfield) (N) Gutschickia subangulata (Jones anJ Kirkby) (N) STRATIGRAPHIC DISTRIBUTION 33 * Healdia coryelli Kellett (N, S) Hollinella emaciata (Ulrich and Bassler) (N) Hollinella gibbosa Kellett (N, S) *Hollinella moorei Cooper, n. sp. (N) Jonesina elongata Cooper, n. sp. (S) Lochriella ampla Cooper, n. sp. (S) Seminolites elongatus Coryell (S) *Silenites silenus Coryell and Booth (N) A number of species indicate a close correlation of this zone with the Way- land shale of Texas and the middle Vir- gil of Kansas. Good markers, suggest- Ti Val. Des Moines Missouri Virgil Fig. 29 — Distribution of ostracode species oc- curring in the Newton and Shumway zones (horizon 26). ing that this zone is of upper Shawnee or even possibly lower AVaubaunsee age, are Bairdia pinnula Coryell and Booth (Wayland shale), Cavellina nebrascensis (Geinitz) (Burlingame-Permian), Heal- dia coryelli Kellett (Howard forma- tion), Hollinella moorei Cooper, n. sp., (Wayland shale), and Silenites silenus Coryell and Booth (Wayland shale). This large fauna is fairly evenly dis- tributed between the Newton (22 species) and Shumway (28 species) ; 18 species are common to both. As would be ex- pected most of the unrestricted species are found in the zones below this one (fig. 29). The following species range above and below this zone. About 60 percent are from the Newton, and as in the Shum- way the predominance is downward. I Basslerella lacrimosa Cooper, n. sp. (N) IBasslerella ovata Cooper, n. sp. (N) I Bairdia altifro?is Knight (S) i Bairdia beedei Ulrich and Bassler (S) | Bairdia blakei Harlton (S) ^Bairdia demissa Cooper n. sp. (S) [Bairdia hurwitzi Coryell and Booth (N) I Bairdia monstrabilis Cooper, n. sp. (S) I Bairdiacypris ardua Cooper, n. sp. (S, N) ICarbonita inflata (Jones and Kirkby) (N) I Cavellina footei (Coryell and Booth) (N) 1 Cavellina laevis (Bradfield) (N) I Cavellina symmetrica (Payne) (S, N) I Cavellina tongia? (Coryell and Sample) (N) i Cornigella tuberculospinosa (Jones and Kirkby) (N) I Coryellites firma Kellett (N) iCoryellites ovata Cooper, n. sp. (S) i Coryellites palopintoensis (Coryell and Sample) (S) ICoryellites pediformis (Knight) (S) i Coryellites subelliptica (Upson) (S) iCoryellites texensis (Coryell and Sample) (S, N) I Discoidella lingulata Cooper, n. sp. (N) | Ellip sella calcar (Harlton) (N) I Healdia simplex Roundy (N) ^Hollinella burling amensis Kellett (N) I Hollinella oklahomaensis (Harlton) (N) I Hollinella shaivnensis Kellett (S, N) i Moorites elongatus? (Jones and Kirkby) (S) IMoorites indentus Cooper, n. sp. (S) I Moorites knighti (Wilson) (N) I Seminolites truncatus Coryell (S) I Sulcella sulcata Coryell and Sample (N) 34 PENN8YLVANIAN OSTRACODES Wabaunsee Group 14 There are no species that are known to be restricted to this group. Greenup zone. — The Greenup fauna is small (12 species in 5 genera), but contains a disproportionately large num- ber of Bairdia. There are no species of ostracodes common to the Greenup and Omega, thought by some to be equivalent hori- zons. All species of the small Omega fauna are fresh-water types, while none of this character are known to occur in the Greenup. The following are known only from the Greenup : Bairdia concava Cooper, n. sp. Macrocypris Mcurvata Cooper, n. sp. Macrocypris lenticularis Cooper, n. sp. Ti Val. Des Moines Missouri Virgil Fig. 30 — Distribution of ostracode species oc- curring in the Greenup zone (horizon 27) "This name is not in accepted use in Illinois. It is employed in this report to conveniently compare Illinois strata with those in the Midcontinent region. Woodbury zone. — The youngest ostra- code-bearing zone in the Pennsylvanian of Illinois includes only one restricted species Ectodemites edsonae (Bradfield) Ti Val. Des Moines Missouri Virgil Fig. 31 — Distribution of ostracode species oc- curring in the Woodbury zone (horizon 28). previously known from the Hoxbar group of Oklahoma. The fauna is small (20 species in 10 genera) and is domin- ated by the presence of 5 species of Bairdia. Other genera are represented by one to two species each. The unre- stricted species are predominately Vir- gil in age, with lesser numbers in the Missouri and upper Des Moines. COLLECTING LOCALITIES 10. 11. 12. 14. 15. 16. NW.y 4 sec. 11, T. 5 S., R. 4 W., Spencer County, Indiana. Shale on top of Fulda limestone; collection 942-2. NW.14 sec. 20, T. 6 S., R. 4 W., Spencer County, Indiana. Shale below Ferdi- nand limestone; collection 943-1, 2. NE.% sec. 21, T. 17 N., R. 1 E., Henry County, Illinois. Shale below Seville limestone; collection 510 by H. L. Geis. SW.14 sec. 32, T. 14 N., R. 2 W., Mercer County, Illinois. Shale between Seville limestone beds; collection 500 by H. L. Geis. S.W. 1 ^ sec. 5, T. 14 N., R. 2 W., Mercer County, Illinois. Shale bands in Seville limestone; collection 502A, B by H. L. Geis. SW.% sec. 24, T. 15 N., R. 4 W., Mercer County, Illinois. Shale parting in upper part of Seville limestone; collec- tion 504A by H. L. Geis. SW.14 sec. 26, T. 17 N., R. 1 W., Rock Island County, Illinois. Shale on top of Seville limestone; collection 508 by H. L. Geis. SE.1,4 sec. 14, T. 12 N., R. 2 W., Warren County, Illinois. Shale below Seville limestone, collection 499-1. NW.14 sec. 32, T. 1 N., R. 2 W., Brown County, Illinois. Shale below Seahorne limestone; collection 608-1. Sec. 1, T. 73 N., R. 20 W., Lucas County, Iowa. Shale above, between, and below lower Seahorne limestone; collection 663-1 by J. M. Weller. SE.14 sec. 13, T. 72 N., R. 16 W., Monroe County, Iowa. Shale below lower Seahorne limestone; collection 664-1 by J. M. Weller. NE.& sec. 36, T. 17 N., R. 4 W., Rock Island County, Illinois. Irregular shale bands in Seahorne limestone; collec- tion 507 by H. L. Geis. SW.1,4 sec. 36, T. 17 N., R, 9 W., Vermil- ion County, Indiana. Shale from Wiley cyclothem; collection 575-1. SW.y 4 sec. 6, T. 2 S., R. 3 W., Brown County, Illinois. Shales adjacent to Oak Grove limestone beds; collection 607-1, 2, 3, 5. SE.14 sec. 6, T. 5 N., R. 3 E., Fulton County, Illinois. Shale between Oak Grove limestone beds; collection 487C by H. L. Geis. NW.y 4 sec. 17, T. 5 N., R. 4 E., Fulton County, Illinois. Shale above Liver- pool limestone; collections 486A and 553B by H. L. Geis. 17. SE.14 sec. 17, T. 8 N., R 3 E., Fulton County, Illinois. Shale in Liverpool marine zone; collection 620-1, 2; clod from limestone in Liverpool marine zone; collection 620-3, 4. 18. NW.i/4 sec. 20, T. 8 N., R. 3 E., Fulton County, Illinois. Shale between Liver- pool limestone beds; collection 496C by H. L. Geis. 19. S.y 2 sec. 36, T. 17 N., R. 4 E., Henry County, Illinois. Shale above and be- low upper bed, Liverpool limestone; collection 627-2. 20. SW.14 sec. 35, T. 34 N., R. 1 E., LaSalle County, Illinois. Shale between thin limestones of Oak Grove formation; collections 403A, D by H. L. Geis. 21. NE.% sec. 30, T. 12 N., R. 1 W., War- ren County, Illinois. Shale below Liver- pool limestone; collection 498 by H. L. Geis. 22. SE.14 sec. 29, T. 2 S., R. 6 W., Adams County, Illinois. Shales in and below lower limestone, Liverpool cyclothem; collection 470-1, 2, 3. 23. NW.14 sec. 21, T. 6 N., R. 3 E., Fulton County, Illinois. Shales between lime- stone members, Liverpool cyclothem; collection 618-1. 24. NW.14 sec. 13, T. 10 N., R. 3 E., Knox County, Illinois. Shales between lime- stone members, Liverpool cyclothem; collection 626-1, 2, 3. 25. SE.1,4 and NE.14 sec. 13, T. 1 N., R. 5 W., Adams County, Illinois. Shale be- low base of Hanover limestone; collec- tion 606-1. 26. NW.14 sec. 24, T. 1 N„ R. 5 W., Adams County, Illinois. Shale below Hanover limestone; collection 471B by H. L. Geis, 471-3 by C. L. Cooper. 27. NW\i4 sec. 8, T. 11 N., R. 4 E., Knox County, Illinois. Summum cyclothem; shale between nodular limestone, below coal no. 4, collection 491-1, by H. L. Geis. 28. SW.14 sec. 8, T. 32 N., R. 2 E., LaSalle County, Illinois. Shales above and in top of Hanover limestone; collection 629-2, 3. 29. SW.14 sec. 21, T. 6 N., R. 3 E., Fulton County, Illinois. Shales above and below St. David limestone; collections 488A, B, and C by H. L. Geis. 30. SW.14 sec. 17, T. 6 N., R. 4 E., Fulton County, Illinois. Shale above St. David limestone; collection 615-1. [35] 36 PENNSYLVANIAN OSTRACODES 36. 37. 31. NW.% sec. 8, T. 11 N., R. 4 E., Knox County, Illinois. St. David cyclothem; shale above no. 5 coal; collection 491A by H. L. Geis. 32. SW.y 4 sec. 8, T. 32 N., R. 2 E., LaSalle County, Illinois. Shales below St. David limestone, collection 629-4. 33. SW.14 sec. 9, T. 5 S., R. 6 W., Randolph County, Illinois. Shale below St. David limestone; collection 443-1. 34. SE.14 sec. 25, T. 6 S., R. 5 W., Randolph County, Illinois. St. David limestone; collection 451-2. 35. SE.14 sec. 1, T. 9 S., R. 1 E., Williamson County, Illinois. Shales above St. David limestone; collection 583-2. SE. 1 ^ SW.}4 sec. 30, T. 9 S., R. 4 E., Williamson County. Shale above Crab- orchard limestone; collection 519-1. NE.14 sec. 24, T. 16 N., R. 6 E., Bureau County, Illinois. Shale in Brereton cyclothem; collection 511 by H. L. Geis. 38. NW.i/i sec. 1, T. 7 N., R. 4 E., Fulton County, Illinois. Shale above and below Brereton limestone; collection 489 A, B by H. L. Geis. 39. NE. 1 ^ sec. 1, T. 7 N., R. 4 E., Fulton County, Illinois. Shale above lime- stone, Brereton cyclothem; collection 514A by H. L. Geis. 40. NE.14 sec. 8, T. 14 N., R. 5 E., Henry County, Illinois. Shale at base of Brereton limestone; collection 602-1 by B. C. Parks. 41. NW.y 4 sec. 13, T. 33 N., R. 1 E., LaSalle County, Illinois. Shale below Brereton limestone; collection 406A by H. L. Geis. 42. SE.14 sec. 15, T. 12 N., R. 9 E., Marshall County, Illinois. Shale parting in Brereton limestone; collection 415A by H. L. Geis. 43. NE.14 sec. 3, T. 2 S., R. 10 W., Monroe County, Illinois. Shale above no. 6 coal, Brereton cyclothem; collection 342-1 by J. N. Payne. 44. SE.14 sec. 25, T. 13 N., R. 11 W., Mor- gan County, Illinois. Shale beneath Brereton limestone; collection 109-3 by E. C. Dapples. 45. SW.14 sec. 31, T. 5 S., R. 2 W., Perry County, Illinois. Shale below Brereton limestone; collection 603-1 by B. C. Parks. 46. SW.14 sec. 9, T. 5 S., R. 6 W., Randolph County, Illinois. Shale above Brereton limestone; collection 427-1. 47. NE.1,4 sec. 15, T. 13 N., R. 6 E., Stark County, Illinois. Shales above and be- low Brereton limestone; collection 512B, C, D, by H. L. Geis. 48. SE.i/4 sec. 32, T. 8 S., R. 2 E., William- son County, Illinois. Shales above and below Brereton limestone; collection 584-2, 3. 49. SW.14 SW.14 sec. 3, T. 3 S., R. 4 E., Jefferson County, Illinois. Below Jamestown (?) limestone; collection 598-1 by B. C. Parks. 50. NE.i/4 sec. 18, T. 12 N., R. 9 W., Macou- pin County, Illinois. Shale between and beneath Jamestown (?) limestone; collection 108-7, 8 by E. C. Dapples. 51. SE14 sec. 22, T. 5 S., R. 6 W., Ran- dolph County, Illinois. Shaly layers in the base of Jamestown limestone; col- lection 578-1, 2. 52. SE.14 sec. 32, T. 8, S., R. 2 E., William- son County, Illinois. Jamestown lime- stone; collection 584-1. 53. NE.14 NW.i/4 sec. 26, T. 2 N., R. 1 W., Schuyler County, Illinois. Shale breaks in Pokeberry limestone; collection 456 by H. R. Wanless. 54. NE.% NE.14 sec. 25, T. 8 S., R. 10 W., Jersey County, Illinois. Shale below Piasa limestone; collection 636-1. 55. NE.14 sec. 11, T. 16 N., R. 6 W., (Ralls Ford), Sangamon County, Illinois. Sparland cyclothem, one foot above coal, collection 102-3 by E. C. Dapples. 56. SE.14 sec. 11, T. 16 N., R. 6 W., Sanga- mon County, Illinois. Shale in upper part of Sparland cyclothem; collection 463C by H. L. Geis. 57. SE14 sec. 24, T. 16 N.,R. 10 E. on Negro Creek, % mile southwest of Seaton- ville, Bureau County, Illinois. Shales near base of stratigraphic section, Gimlet cyclothem; collection 410-1, 2. 58. SE.14 NW.y 4 sec. 10, T. 8 N., R. 9 W., Macoupin County, Illinois. Shale be- low limestone, Gimlet cyclothem; col- lection 601-1 by J. N. Payne. 59. NW.14 sec. 6, T. 8 N., R. 5 E., Peoria County, Illinois. Shale between thin limestone 8 feet below Lonsdale lime- stone; collection 89-1 by E. C. Dapples. 60. NE.14 sec. 10, T. 8 N., R. 6 E., Peoria County, Illinois. Shale from nodular zone in lower part of upper bench of Lonsdale limestone; collection 83-1 by E. C. Dapples. 61. NE.14 sec. 11, T. 8 N., R. 6 E., Peoria County, Illinois. Shale below Lo;v5dale limestone; collection 79-2 by E. C. Dapples. 62. SE.14 sec. 16, T. 12 N., R. 9 E., Marshall County, Illinois. Shale below lower bench of Lonsdale limestone; collection 59-1 by E. C. Dapples; 414A, B, D by H. L. Geis. COLLECTING LOCALITIES 37 63. NW.14 sec. 25, T. 19 N., R. 13 W., Ver- milion County, Illinois. Shale above Lonsdale limestone; collection 516 by H. L. G*is. 64. NE.y 4 sec. 28, T. 14 N., R. 10 W., Edgar County, Illinois. Shale above Brouillet coal; collection 727-2 by A. F. Agnew. 65. SE.14 sec. 1, T. 8 N., R. 6 E., Peoria County, Illinois. Upper shale, Exline formation; collection 770-1 by H. R. Wanless. 66. NE.14 sec. 22, T. 14 N., R. 7 E., Stark County, Illinois. Shales above and be- low Exline limestone; collection 513A, B by H. L. Geis. 67. S-C sec. 6, T. 67 N., R. 17 W., Apanoose County, Iowa. Shale above Exline lime- stone; collection 657-4 by J. M. Weller. 68. SW.1/4 sec. 29, T 14 N., R. 10 W., Edgar County, Illinois.' Shale above Trivoli limestone; collection 538-1, 2. 69. SW.14 sec. 3, T. 8 N., R. 5 E., Peoria County, Illinois. Shale above lime- stone at type locality of Trivoli (No. 8) coal; collection 62-1 by E. C. Dapples. 70. SW.y 4 sec. 3, T. 8 N., R. 5 E., Peoria County, Illinois. Shale between upper and lower Trivoli limestone; collection 417 by H. L. Geis. 71. SE.14 sec. 30, T. 16 N., R. 5 W., Sanga- mon County, Illinois. Shale 1% feet above Trivoli (No. 8) coal; collection 100-1 by E. C. Dapples. 72. SW.14 sec. 12, T. 8 S., R. 4 E., William- son County, Illinois. Shale below mid- dle Trivoli limestone; collection 596-1; shale above middle Trivoli limestone; collection 596-2. 73. SW.14 sec. 34, T. 3 N., R. 8 W., Madison County, Illinois. Shale from Collins- ville limestone; collection 379-1 by J. N. Payne. 74. SW.14 sec. 10, T. 9 N., R. 14 W., Clark County, Illinois. Shale break in Shoal Creek limestone; collection 542-4. 75. SW.14 sec. 11, T. 2 N., R. 4 W., Clinton County, Illinois. Shale above Shoal Creek limestone; collection 820-1. 76. NE.14 sec. 34, T. 2 N., R. 4 W., Clinton County, Illinois. Shale below Shoal Creek limestone; collection 373-1 by J. N. Payne. 77. NW.14 sec. 36, T. 10 N., R. 7 W., Macou- pin County, Illinois. Shale parting in upper Shoal Creek limestone; collec- tion 449A by H. L. Geis. 78. NW.14 sec. 4, T. 4 N., R. 6 W., Madison County, Illinois. Shale in Carlinville cyclothem; collection 374-1 by J. N. Payne. 79. SE.14 sec. 6, T. 6 N., R. 4 W., Bond County, Illinois. Shale above "Cen- tralia" limestone; collection 420 by H. L. Geis. 80. NE.14 sec. 35, T. 2 N., R. 3 W., Clinton County, Illinois. "Centralia" lime- stone; collection 425A by H. L. Geis. 81. SE.14 sec. 4, T. 1 N., R. 1 E., Marion County, Illinois. "Centralia" forma- tion; collection 428-1, 2, 3. 82. SW.14 sec. 19, T. 7 N., R. 4 W., Mont- gomery County, Illinois. Shales above and below "Centralia" limestone; col- lections 419A, B by H. L. Geis. 83. SW.i/4 sec. 10, T. 9 N., R. 14 W., Clark County, Illinois. Shale below Macou- pin limestone; collection 542-1, 2. 84. SW.14 sec. 2, T. 14 N., R. 11 W., Edgar County, Illinois. Shale on top of Ma- coupin limestone; collection 571-1, 2. 85. NW.14 sec. 2, T. 9 N., R. 7 W., Macou- pin County, Illinois. Shale parting in Macoupin limestone; collection 418E by H. L. Geis. 86. NW.i/4 sec. 2, T. 9 N., R. 7 W., Macoupin County, Illinois. Shale above Macou- pin coal; collection 334-1 by J. N. Payne. 87. SE.14 sec. 3, T. 13 N.,R.5 W., Sangamon County, Illinois. Middle shale, Macou- pin formation; collection 726-2 by J # N. Payne. 88. NW.14 sec. 33, T. 16 N., R. 11 E., Bu- reau County, Illinois. Shale below La- Salle limestone; collections 407B, C by H. L. Geis, and 407-2, 3, 4, 6 by C. L. Cooper. 89. NW.14 sec. 33, T. 16 N., R. 11 E., Bu- reau County, Illinois. Marl below La- Salle limestone; collection 338-1 by J. M. Schopf. 90. NE.14 sec. 28, T. 12 N., R. 1 W., Chris- tian County, Illinois. Weathered lower part of Millersville limestone; collec- tion 848-1 by J. N. Payne. 91. NE.iA sec. 6, T. 32 N., R. 2 E., LaSalle County, Illinois. Shale from LaSalle cyclothem; collection 446A by H. L. Geis. 92. NW.14 sec. 5, T. 3 N., R. 11 W., near old highway bridge over Embarrass River, Lawrence County, Illinois. Shale above Livingston (?) limestone; collec- tion 359-1. 93. NE.14 sec. 12, T. 7 S., R. 9 E., White County, Illinois. Shale below and with- in Livingston (?) limestone; collection 745-1, 2. 94. SE.14 sec. 1, T. 11 N., R. 12 W., Clark County, Illinois. "Fresh-water" lime- stone and shale in Cohn cyclothem; col- lection 543-la. 95. NE.14 sec. 2, T. 11 N., R. 12 W., Clark County, Illinois. Shales in Cohn cyclo- them; collection 545 B, C by H. L. Geis. 38 PENNSYLVANIAN OSTRACODES 98. 99. 9$. NWM sec. 29. T. S X.. R. 1 E.. Fayette County. Illinois. Shale above lime- stone bed. Colin cyclothem: collection 749-3. 97. NW.% sec. 25. T. S X.. R. 3 E.. Fayette County. Illinois. Shales between lime- stone beds. Bogota cyclothem: collec- tion 748-2, 3. 4. NW.% sec. 25. T. S X.. R. 3 E.. Fayette County. Illinois. Upper Bogota forma- tion: collection 70S by J. X". Payne. XE. X 4 sec. 17. T. 5 X.. R. S E.. Jasper County. Illinois. Shale under marine limestone. Bogota cyclothem: collection 740-2. 100. SE.% sec. 20. T. 5 X.. R. S E.. Jasper County. Illinois. Shale below lime- stone bed. Bogota cyclothem: collection 741-2. 101. XW. 1 ! sec. 27. T. 7 X.. R. 10 E.. Jasper County. Illinois. Shale below lime- stone. Bogota cvclothem; collection 734-2. 102. SW.% sec. 11. T. 33 X.. R. 1 E.. LaSalle County. Illinois. Shales between lime- stone beds in the Little Vermilion cyclothem; collection 404A. B by H. L. Geis. 103. SE.% sec. 36. T. 33 X.. R. 1 E.. LaSalle County. Illinois. Shale in Little Ver- milion limestone: collection 401A by H. L. Geis; collection 401-1 by C. L. Cooper. 104. XE.U sec. 4. T. 4 X., R. 5 E.. Clay County. Illinois. Shale below Shelby- ville limestone: collection 436B by H. L. Geis. 105. NW.% sec. 1. T. 9 X.. R. 3 E., Shelby County. Illinois. Shale between nodular "fresh-water" limestones below Shelby- ville coal underclay; collection 339-2. 106. Cen. N.% sec. 22. T. 10 X.. R. 6 E.. Shelby County. Illinois. Shale above Shumway limestone: collection 725-1. 107. SW.% sec. 22. T. 10 X.. R. 6 E., Shelby County. Illinois. Shale above and be- low upper limestone. Shumway cyclo- them: collection 752-1. 2. 10S. SE.! 4 sec. 35, T. 9 X.. R. 7 E.. Cumber- land County. Illinois. Shale parting in Xewton limestone: collection 719-1, 2. 109. SW.i 4 sec. 26. T. 9 X..R. 5 E.. Effingham County. Illinois. Shales in Shumway cyclothem: collection 439. 111. 11: IIS 114. 116. 11" 110. NW.% sec. 6. T. 6 X., R. 10 E.. Jasper County. Illinois. Shale below Xewton limestone: collection 711-1. NW.% sec. 15, T. 7 X.. R. 10 E.. Jasper County. Illinois. Shale below Xewton limestone: collection 732-1. SW.! 4 sec. 33. T. 12 X.. R. 3 E.. Shelby County. Illinois. Shales above and be- low thin limestone. Xewton cyclothem; collection 440A. B by H. L. Geis: 440-1. 2 by C. L. Cooper. XE.^ sec. 3, T. 9 X.. R. 9 E.. Cumber- land County. Illinois. Shale between nodules in upper part of Greenup lime- stone: collection 552-3. XW.i 4 sec. 10. T. 9 X.. R. 9 E.. Cumber- land County. Illinois. Shale above Greenup limestone; collection 723-1. 115. SE.% sec. 32. T. 9 X.. R, S E., Cumber- land County. Illinois. Shales in Wood- bury cyclothem; collection 720-1, 2. North side of route 40. 1.4 miles west of Ogden. Kansas. YVreford formation; collection 2S1A. B by H. L. Geis. Shale pit of Hydraulic Pressed Brick Company, east of Dallas, road between Conway and Olive Streets. St. Louis- County. Missouri. Shale portions in Lexington caprock. Knight's (1928, p. 336) locality 9: collection S9S-1 by R. V. Hollingsworth. US. NW.% sec. IS. T. 4 X.. R. 17 E.. Pitts- burg County, Oklahoma. Wapanucka limestone in old cement-plant quarry 1% miles south of Hartshorne; hard dark shale at west end of cut. 30-40 feet above base: collection 217B by H. L. Geis. 119. High north bank of Concho River, just east of Concho-Tom Green County line. Texas, and 200 yards west of ford on J. W. Bailey farm. Shaly lime- stone at top of section of "Arroyo" (Canyon) formation; collection 1S6A by H. L. Geis. 120. State Highway 21. 0.65 mile south of Barnett's store, near Wirt Wood Coun- ty line. West Virginia. Shale below a limestone about 125 feet below the Nineveh limestone member. Greene formation. Dunkard series; collection 693-3. SYSTEMATIC DESCRIPTIONS Family Acronotellidae Swartz, 1936 Genus Monoceratina Roth, 1928 MONOCERATINA ARDMORENSIS (HarltOIl) Plate 1, figure 9 Cythereis? ardmorensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 211, pi. 33, figs. 14a-c; Upper Glenn formation, Okla- homa. — Harlton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 270, pi. 2, figs. 18a, b; Wapanucka limestone and Dornick Hills group, Oklahoma. Monoceratina ardmorensis, Harlton, 1933, Jour. Paleontology, vol. 7, p. 21, pi. 7, figs. 14a, b; Johns Valley shale, Okla- homa. Carapace small, elongate; dorsal mar- gin straight ; ventral margin convex, an- terior end rounded; posterior end acu- minate; ventral spine large, sharp, flar- ing at base, and extended laterally for considerable distance. Length, 0.60 mm; height, 0.28 mm. Fulda limestone, locality 1. Monoceratina bradfieldi Cooper, n. sp. Plate 1, figures 1-6 Monoceratina n. sp. Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 77, pi. 1, figs. 16-18, 20; Deese group, Okla. Carapace small, elongate, lateral out- line subrectangular ; hinge line long, straight, ends subequally rounded; ven- tral margin convex; depressed areas medially and anteriorly broad and very shallow ; ventral spine short, widely flar- ing at base, joining an inflated portion of posterior half of shell; posterior end unusually wide; surface punctate. Length, 0.50 mm; height, 0.25 mm; width, 0.22 mm. This species is characterized by the low, broad anterior and posterior infla- tions and by the unusually wide poster- ior end. Little Vermilion cyclothem, locality 105. Monoceratina lewisi Harris and Lalicker Plate 1, figures 10-12 Monoceratina leioisi Harris and Lalicker, 1932, Am. Midland Naturalist, vol. 13, p. 398, pi. 36, figs. 6a, b; Ft. Riley lime- stone, Kansas. — Kellett, 1935, Jour. Paleontology, vol. 9, p. 158, pi. 16, figs. 4a, b; Kanwacka shale to Winfield formation, Kansas. Triceratina wrefordensis Upson, 1933, Ne- braska Geol. Survey, Bull. 8, p. 29, pi. 3, figs, la-c; Hughes Creek shale, Nebraska. Carapace small, elongate ; dorsal mar- gin straight; ventral margin convex, al- most straight in central portion; anter- ior end rounded, posterior end acumin- ate to bluntly rounded; ventral spine long, slender, sharply directed laterally with only slight inclination posteroven- trally ; central node above spine, slightly closer to dorsal margin, anterior node about central in anterior half; surface punctate. Length, 0.43 mm ; height, 0.21 mm ; width, 0.21 mm. Gimlet zone, locality 62. Monoceratina macoupeni Scott and Borger Plate 1, figure 13 Monoceratina macoupeni Scott and Borger, 1941, Jour. Paleontology, vol. 15, p. 355, pi. 49, figs. 2, 3; Macoupin formation, Illinois. Monoceratina lawrencevillensis Scott and Borger, 1941, idem, p. 355, pi. 49, figs. 8, 9; Macoupin formation, Illinois. Carapace small, elongate; dorsal mar- gin straight, and produced into very long acuminate posterior termination ; ventral margin flat to slightly convex; anterior end rounded. Length, 0.50 mm ; height, 0.22 mm ; width, 0.18 mm. The ventral spine is the only surface ornamentation showing on this specimen, which is a cast. Gimlet zone, locality 62. [39] 40 PENNSYLVANIA* 7 OSTRACODES Family Aechminidae Swartz, 1936 Genus Ardmorea Bradfield, 1936 Ardmorea gibberosa (Knight) Plate 1, figures 7, 8 Aechminaf gibberosa Knight, 1928. Jour. Paleontology, vol. 2, p. 235, pi. 31, figs. 9a, b; Pawnee limestone, 16 Missouri. Ardmorea gibberosa Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 39, pi. 13, figs. 4a, b; Hoxbar formation, Oklahoma. Carapace subelliptical to semicircular in lateral outline, dorsal margin arched, ventral margin convex, ends equally rounded ; hinge long, straight, depressed in central portion; centrodorsal region inflated; surface smooth, unornamented. Length, 0.47 mm ; height, 0.27 mm ; width, 0.21 mm. Lateral outline is almost identical to Aechmina cuspidata Jones and Holl, (1869, p. 218), but the long medial spine has degenerated until only a slightly inflated area remains. Seville and Gimlet zones, localities 6, 62. Family Bairdiidae Sars, 1887 Genus Bairdia McCoy, 1846 Bairdia ac cumin ata Cooper, n. sp. Plate 1, figures 27, 28 Carapace elongate, dorsum broadly arched, ventral margin slightly convex, curving very gradually from a point slightly ahead of middle to anterior end ; posteroventral curvature slight to meet short, low, acuminate posterior back; anterior end narrow, rounded, slightly below midheight ; overlap conspicuous along dorsum, wanting along venter; surface smooth. Length, 1.05 mm ; height, 0.51 mm ; width, 0.34 mm. B. acuminata can be recognized by its very short acuminate beak lying well below midheight. Bogota and Little Vermilion zones, lo- calities 103, 107. ^According to recent correlations, (see Weller. Wan- less, Cline, and Stookey, 1942) the beds originally designated by Knight as upper Fort Scott and Pawnee limestone in the St. Louis area are now referred to the St. David (Ill.)-Houx (la. -Mo.) and Piasa (111.)- Worland (la. -Mo.) limestones respectively. Bairdia altifrons Knight Plate 1, figures 20-22 Bairdia altifrons Knight, 1928, Jour. Paleon- tology, vol. 2, p. 324, pi. 43, figs. 6a, b; upper Ft. Scott formation, Missouri. Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 70, pi. 5, figs. 10a, b; Wewoka-Holdenville formations, Okla- homa. — Kellett. 1934, Jour. Paleontol- ogy, vol. 8, p. 135, pi. 18, figs. 6a, b; Ft. Scott formation, Kansas. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 42, pi. 4, figs. 4, 5; Stanton formation, Nebraska. Bairdia chasae Kellett, 1934, Jour. Paleon- tology, vol. 8, p. 135, pi. 18, figs. 5a-d; pi. 19, figs. 5a-d; Upper Shawnee group, Kansas. Bairdia hoxbarensis, Harlton, 1929, Texas Univ. Bull. 2901, p. 154, pi. 3, figs, la-d; Canyon series, Texas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 86, pi. 6, fig. 8; Hoxbar group, Oklahoma. Carapace ovate or subellipsoid ; dor- sal margin strongly convex; ventral margin straight to slightly concave ex- cept near anterior ; anterior end broadly rounded; posterior beak short and well below midheight ; greatest height nearly central ; overlap strong, complete around entire margin, even along posterodorsal slope. Length, 1.14 mm; height, 0.54 mm; width, 0.42 mm. B. altifrons is characterized by the broadly arched dorsum, the prominent overlap, and a short, steep posterodorsal slope to the beak. This species, reported from the upper Des Moines and Missouri series of the Midcontinent, is found in almost every zone throughout the Pennsylvanian sys- tem in Illinois, from the Seville to the Shumway, localities 8, 14, 38, 40, 53, 54, 62, 66, 68, 77, 83, 85, 88, 99, 103, and 109. Bairdia ampla Reuss Plate 1, figures 45-49 Cythere (Bairdia) ampla Reuss, 1854, Jahres- ber.Wetterauer Gesell. Gesamm. Naturk. Hanau 1851-53, p. 68, figs. 7a, b; Zech- stein, Germany. ■ — Jones and Kirkby, 1860, Tyneside Nat. Field Club Trans., vol. 4. pp. 162. 166. pi. 11, figs. 14a-c, 19a-f; Permian, Great Britain. BAIRDIIDAE 41 Bairdia texana Harlton, 1927 (not Harlton, 1929), Jour. Paleontology, vol. 1, p. 210, pi. 33, fig. 9, Hoxbar group, Oklahoma. Carapace elongate, dorsal margin reg- ularly arched, ventral margin convex; centrodorsal and anterodorsal margins merge imperceptibly ; posterodorsal slope short and steep, resulting in a small posterodorsal angle; beak short, wide, and acuminate ; anterior end broadly rounded ; overlap pronounced around dorsal margins, slight along venter, especially near each end ; surface smooth. Length, 1.16 mm; height, 0.59 mm; width, 0.46 mm. There is considerable variation in the forms described under B. ampla, which range in age from Lower Mississippian to Upper Permian. If the types were assembled, at least four distinct species probably could be recognized ; two from the Permian of Great Britain (Jones and Kirkby, 1860) and Germany (Rich- ter, 1867) one from the Carboniferous (Chester) of Great Britain and Mongo- lia (Jones & Kirby, 1879, 1892) and one from the Tournasian (Kinderhook) of Germany (Kummerow, 1939). The Illi- nois and Oklahoma forms from the up- permost Pennsylvanian formations ap- pear to be comparable to B. ampla, Jones and Kirkby, 1860. B. altifrons Knight also possesses the regularly arched dorsum of B. ampla, but lacks the concave venter. Exline to Greenup zones, localities 66, 108, 109, 112, 113 and 114. Bairdia angusta Cooper, n. sp. Plate 1, figures 41-44 Carapace short, tumid; dorsal margin arched, ventral margin straight ; postero- and anteroventral slopes merge smoothly with dorsum ; anterior end very broad, rounded, termination above midheight; posterodorsal slope straight or slightly convex; beak short, wide, and acumin- ate; overlap greatest on middorsal and ventral margins ; very slight on anterior margin; surface granulose. Length, 1.21 mm; height, 0.79 mm; width, 0.62 mm. B. angusta has a wider anterior and a straighter dorsum than B. seminalis al- though the posterior development seems identical. It also lacks the acuminate anterior of B. olakei Harlton and the ex- tended beak of B. crassa Harlton. Seville formation, locality 4. Bairdia ardmorensis Harlton Plate 1, figures 14, 15 Bairdia ardmorensis Harlton, 1929 (not 1933), Am. Jour. Sci. ser. 5, vol. 18 5 p. 267, pi. 2, fig. 11; Dornick Hills group, Oklahoma. Carapace large, elongate ; dorsal mar- gin highly arched, ventral margin con- vex; anterior end rounded but narrow; posterior end long, narrow, and term- inated well below midheight; overlap very wide in centrodorsal area, decreas- ing on downward slope towards ends, very faint along postero- and anteroven- tral margins, increasing appreciably in center; posterodorsal slope long and straight. Length, 1.30 mm; height, 0.69 mm; width, 0.45 mm. Bairdia cf. B. ardmorensis (Bradfield, 1935, p. 92) may be young moult of this species. Ferdinand zone, locality 2. Bairdia beedei Ulrich and Bassler Plate 1, figures 35-40 Bairdia beedei Ulrich and Bassler, 1906, U. S. Nat. Museum Proc, vol. 30, p. 161, pi. 11, figs. 19, 20; Cottonwood shale, Kansas. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 69, pi. 5, figs. 9a, b; Holdenville formation, Oklahoma. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 16, pi. 1, figs. 4a-c; Garrison shale, Nebraska. — Kellett, 1934, Jour Paleontology, vol. 8, p. 123, pi. 14, figs la-h, 2; Upper Pennsylvanian and Per mian, Kansas. — Johnson, 1936, Ne braska Geol. Survey Paper 11, p. 38, pi 4, figs. 1, 2; Missouri series, Nebraska — Payne, 1937, Jour. Paleontology, vol 11, p. 282, pi. 38, figs. 9a, b; pi. 39, figs la, b; Hayden Branch formation, Indiana. 42 PENNSYLVANIA^ OSTRACODES Bairdia beedei abrupta Ulrich and Bassler, 1906. U. S. Xat. Museum Proc, vol. 30. p. 162, pi. 11. figs. 21. 22; Cottonwood shale, Kansas. Bairdia beedei inflata Payne. 1937. Jour. Paleontology, vol. 11. p. 2S3. pi. 39, figs. 2a. b; Hayden Branch formation. Indiana. Bairdia hispida Harlton, 192S. Jour. Paleon- tology, vol. 2, p. 140. pi. 21. fig. 14: Cisco. Texas. — Harlton, 1929, Univ. Texas Bull. 2901. p. 155. pi. 3, figs. 2a. b: Canyon. Texas. — Delo, 1930. Jour. Paleontology, vol. 4. p. 163. pi. 12, figs. 14a. b: Pennsylvania. Texas. Bairdia hispida aha Bradfield. 1935. Bull. Am. Paleontology, vol. 22, p. SS, pi. 6. figs. 6a. b; Hoxbar, Oklahoma. Bairdia moorei Knight. 192S, Jour. Paleon- tology, vol. 2. p. 31S. pi. 43. figs, la-c; Upper Ft. Scott formation. Missouri. —Coryell and Billings. 1932. Am. Mid- land Naturalist, vol. 13. p. 173. pi. 17, fig. 4: Wayland shale. Texas. Bairdia icrefordensis Upson. 1933. Nebraska Geol. Survey Bull. S. p. 22. pi. 2. figs. 5a, b; Wreford limestone, Nebraska. Carapace large, tumid, dorsal and ventral margins broadly rounded, form- ing acuminate anterior where termina- tion is at midheiglit ; beak short, blunt. just below midheiglit ; overlap conspicu- ous along all margins except anterior ; articulation at center of hinge line al- most straight for half of length forming- obtuse angle at its junction with poster- odorsal slope ; sinuous articulation of anteroventral angle very marked ; sur- face smooth. Length. 1.39 mm ; height. 0.90 mm ; width, 0.63 mm. There is considerable variation in the general features and form ratio of this species. Kellett (1934. p. 124) lists a variation of 1.65 to 1.74 in form ratio. and the length of described species of 0.77 to more than 1.4 mm. Due to this variation it does not seem feasable to list varieties of B. bcedci, and for this reason the several varieties described have been placed in synonomy. Brereton to Shumway zones, localities 4. crassimarginata snmewhat resembles B. peracuta War- thin from a comparable horizon in Oklahoma, but i^ h' Woodbury zones, localities 88, 109, 115. Bairdia demissa Cooper, n. sp. Plate 2. figures 23-26 Carapace low. elongate ; dorsal arch broad and low, merging imperceptibly into posterod«»r>al slope; ventral margin straight ; anterior end bread, rounded, and terminated at midheight ; posterior beak h»n<_ r . acuminate, with termination exceptionally low; greatest height slight- ly anterior; overlap moderate along anterodorsal and midventral margins; slight at other points ; surface smooth. Length. 1.08 mm ; height, 0.54 mm ; width. 0.45 mm. B. demissa is similar to B. perincerta Kellett from comparable beds in the Midcontinent. but the former is more elongate, the dorsal arch is lower and broader, with the greatest height ante- rior. It does not possess the dorsal ridge of B. perincerta and B. power si Kellett, nor the angle on the posterodorsal slope of B. schotti Coryell and Booth, formed by the junction of lines of articulation. Shumway and Woodbury zones, locali- ties 109, 115. Bairdia dissluelis Cooper, n. sp. Plate 2, figures 27-29 Carapace tumid, dorsal margin of left valve broadly arched, of right valve flattened, giving appearance of variable overlap along dorsum ; ventral margin straight ; posterior beak short, wide, acu- minate and below midheight; anterior end rounded, termination at midheight ; greatest thickness posterior ; overlap ap- parently due to much greater size of left valve : line of articulation depressed, es- BAIBDUDAE 4o pecially along dorsal and ventral mar- gins ; surface smooth. 3 Length, 1.05 mm; height, 0.67 mm; width, 0.52 mm. B. dissimilis is differentiated by its un- equal valves, both as to size and shape, by the lateral outline and by the de- pressed articulation along the dorsum and venter. It differs from B. seminalis Knight in that the dorsum of the right valve of the latter is arched, as compared to the flat dorsum of the Illinois species. Ferdinand and Seville zones, localities 2,8. Bairdia garrisonensis Upson Plate 2, figures 14-18 Bairdia garrisonensis Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 20, pi. 1, figs. lOa-c; Garrison shale, Nebraska. — Kel- lett, 1934, Jour. Paleontology, vol. 8, p. 134, pi. 17, figs. 5a-c; Deer Creek to Wre- ford formations, Kansas. — Scott and Borger, 1941, Jour. Paleontology, vol. 15, p. 354, pi. 49, fig. 19, Macoupin forma- tion, Illinois. Bairdia auricula, Bradfield, 1935 (not Knight, 1928), Bull. Am. Paleontology, vol. 22, p. 89, pi. 6, figs. 13a, b; Hoxbar group, Oklahoma. Carapace large, somewhat tumid, dor- sal margin very highly arched, ventral margin slightly convex; overlap very pronounced in centrodorsal region, less so along venter, very slight along anterior and posterodorsal margins; posterior beak short, wide, below midheight ; an- terior end rounded with termination at midheight ; posterodorsal slope straight ; surface smooth to granulose. Length, 1.52 mm; height, 0.95 mm; width, 0.63 mm. Shumway zone, locality 109. Bairdia cf. B. glennensis Harlton Plate 2, figures 6, 7 Bairdia glennensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 210, pi. 33, fig. 10; Upper Glenn formation, Oklahoma. — Knight, 1928, Jour. Paleontology, vol. 2, p. 325, ,pl. 43, figs. 8a, b; Pawnee lime- stone, Missouri. — Kellett, 1935, Jour. Paleontology, vol. 9, p. 133, pi. 18, figs. 4a-e; Upper Pennsylvanian and Lower Permian, Kansas. Bairdia subelongata, Harlton, 1927 (not Jones and Kirkby), Jour. Paleontology, vol. 1, p. 210, pi. 33, fig. 11, Upper Glenn formation, Oklahoma. Carapace very elongate, dorsal margin slightly bowed, antero- and posterodor- sal slopes very low, ventral margin straight except near extremities, where margin swings upward in a gradual curve ; anterior end rounded, terminated about midheight; posterior beak long and narrow; overlap greatest along dorsum. Length (fig. 6), 1.42 mm; height, 0.62 mm ; width, 0.43 mm. This long-ranging species (Lower Pennsylvanian into Permian) has an un- usually large but variable form ratio (2.25-2.75). It also may be distinguish- ed by its very low dorsal arch and straight venter. Its general outline is somewhat similar to B. legumen Jones and Kirkby, but lacks the acute anterior end of the latter. Fulda and Seahorne zones, localities 1, 9. Bairdia harltoni Cooper, n. sp. Plate 2, figures 30, 31 Bairdia ardmorensis Harlton, 1933 (not Harlton, 1929), Jour. Paleontology, vol. 7, p. 25, pi. 7, fig. 8; Johns Valley shale, Oklahoma. Carapace elongate, lenticular, dorsal margin arched, antero- and posteroven- tral slopes straight, the latter more acute ; ventral margin straight in mid- portion only, curving broadly toward each end ; overlap prominent on dorsum and on midventor, less prominent on poteroclorsal slope, very faint elsewhere ; anterior end somewhat acuminate but rounded; beak long and slightly below midheight; surface smooth to faintly granulose. Length, 1.26 mm; height, 0.69 mm; width, 0.48 mm. B. harltoni differs from B. ardmorensis in its lesser form ratio (1.74 cf. 1.84), broader terminations, and in its slightly greater angle of the posterodorsal slope. Seville zone, locality 8. I(i PENNSYLVANIA!! 0STRAC0DE8 BAIRDIA IHhi\ I :i; \l Kelletl Plate 2, figures 21, 22 Bairdia hooverae Kellett, 1934, Jour. Paleon- tology, vol. 8, p. L26, pi. i», figs. na. b; Stanton limestone to Oread formation, Kansas. —Not Payne, L937, Jour. Pale- ontology, vol. li, p. 284, pi. 39, figs. 5a, 1); Hayden Brancb formation, Indiana. Carapace short, tumid, ovate; dorsal arch high, broad; ventral margin si raighl ; anterior end rounded and ai midheighl ; posterior beak short, wide. and acuminate; overlap distincl around entire margin, greatest along anterodor- sal slope ; surface smool h. Length 1.03 mm; height, 0.66 mm; width, 0.5] nun. The Illinois form Ls slightly Less tumid and 1 he cenl ra] porl ion natter In dorsal view than is shown in Kellett 's figure, but agrees, however, in other respects. Payne's form, from a somewhat lower horizon in [ndiana, docs qo1 possess the acuminate beak and prominenl overlap of the younger forms. Payne's speci- men docs not appear to belong to tins species as it does not have the character- istic posterior beak. His drawing is seen to be somewhat misleading when compared with his specimen. LaSalle zone, locality 88. Bairdia iioxbarensis Harlton Plate 2, figures 43, 44 Bairdia Koxbarensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 211, pi. 33, fig. 12; Hoxbar group. Oklahoma. Not Bairdia Iioxbarensis Harlton, 1929, Texas Univ. Bull. 2901, p. 154, pi. 3, figs, la-d. —Kellett, 1934, Jour. Paleontol- ogy, vol. 8, p. 131, pi. 16, figs. 5a-c. — Bradfield, 1935, Bull. Am. Paleontol- ogy, vol. 22, p. 86, pi. 6, fig. S. —Payne, 1937, Jour. Paleontology, vol. 11, p. 284, pi. 39, figs. 6a, b. — Scott and Borger, 1941, Jour. Paleontology, vol. 15, p. 357, pi. 50, fig. 7. Bairdia haworthi Knight, 1928, Jour. Paleon- tology, vol. 2, p. 325, pi. 43, figs. 7a, b: upper Ft. Scott formation, Missouri. Bairdia subelongataf. Knight, 1928 (not Jones and Kirkby), Jour. Paleontology, vol. 2, p. 326, pi. 43, fig. 9; upper Ft. Scott formation, Missouri. Bairdia acetalata Coryell and Billings, L932, Am. Midland Naturalist, rol. L8, p. it::. pi. it, flg. 5; Wayland shale, T< Carapace elongate, dorsal margin regularly arched, antero- and posterodor- sai slopes a regular continuation ol I < > \\ dorsal curvature; ventral margin slight- ly concave ; anterior end rounded ; poste- rior beak wide, sharply acuminate; term- inations al midheighl ; overlap conspicu- ous only along dorsal margin. Lengt li. 1 ,05 nun ; height, <•. Mi nun ; w idi h. 0.35 mm. In addition to the species listed above, Bassler and Kellett I L935, p. 173) in- cluded />'. nebraskensis Upson, />'. aceta- lata Coryell and Billings (also Coryell and Booth, L933), and li. subelongata, Knighl 1927 and 1928 in synonomy with />'. Iioxbarensis. These species, because of the atypical developments of ilie pos- terior termination, have been trans- ferred to the new genus Fabalicypris (p. 59). /'. hoxbarensis Harlton (Brad- field, 1935) with which B. altifrons Knighl was placed in synonomy does mil appear to !>«' conspecific with the former, and lias I n placed with ll. alti- frons, as has ll. hoxbarensis, Barlton, 1929. Brereton to shoal ('reek /ones, locali- ties 38, 68, 76, 77. Bairdia burwitzi Coryell and Booth Plate 2, figures 11-13 Bairdia huricitzi Coryell and Booth, 1933, Am. Midland Naturalist, vol. 14, p. 262, pi. 3, figs. 8, 9; Graham formation, Texas. Bairdia Jongirostris Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 89, pi. 6, figs. 11a, b; Hoxbar group, Oklahoma. Carapace subrhomboidal, dorsal mar- gin strongly arched, ventral margin eon- vex; posterodorsal slope straight and slightly steeper than anterodorsal slope ; anterior end narrow but rounded ; poste- rior beak short, wide, and terminated slightly below midheight ; overlap con- spicuous along all margins except an- tero- and posteroventral ; surface smooth. Length, 1.23 mm; height, 0.77 mm; width, 0.52 mm. BAIBDIIDAE 47 B. hurwitzi is characterized by the high arching of the left valve above the hinge line, and by the polygonal appear- ance formed by the intersection of the straight lines of articulation bordering the dorsal margins. LaSalle and Newton zones, localities 90, 108. Bairdia kingii Reuss Plate 2, figures 36, 37 Bairdia kingii Reuss, 1854 Wetterauer Ges- sell. Naturk. gesaur. Jahresber. Hanan, 1851-1853, p. 67, pi., fig. 4, Zechstein, Germany. — Kirkby, 1858, Annals and Mag. Nat. History, ser. 3, vol. 2, p. 327, pi. 10, figs. 8a, b; Permian, England. — Jones and Kirkby, 1860, Tyneside Nat. Field Club, vol. 4, p. 148, pi. 9, figs. 8a, b; Permian, England. — Geinitz, 1861, Dyas oder die Zechsteinformation und das Rothliegende, vol. 1, p. 34, text-fig. 2 (figs. 10a, b) ; Zechstein, Germany. Cythere (Bairdia) kingii Schmidt, 1867, Neues Jahrb., p. 581, pi. 6, figs. 32, 33; Zechstein, Germany. Bairdia kingii compressa Jones and Kirkby, ibid., p. 148, pi. 9, figs. 7a, b; Permian, England. Bairdia pleoia compressa Kirkby, 1858, ibid., pp. 325, 328, pi. 10, figs. 7a, b; Permian, England. Cythere (Bairdia) plebeia compressa Kirkby, 1861, Geol. Soc. London Quart. Jour., vol. 17, p. 308. Carapace thin, elongate, dorsal margin broadly arched in center, becoming some what flatter towards ends ; ventral mar- gin straight to slightly concave ; poste- rior beak, short, wide, acuminate ; ante- rior end rounded; overlap wanting or faint along all margins except in centro- dorsal area ; carapace smooth. Length, 1.10 mm; height, 0.47 mm; width, 0.30 mm. The size and shape of the Illinois specimens appear to agree in all respects with the European species. The variety compressa (Kirkby), which seems too close to the species for separation, comes from the same horizons and localities. Newton zone, locality 108. Bairdia lunata Bradfield Plate 2, figures 19, 20 Bairdia lunata Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 90, pi. 6, fig. 10; Hoxbar group, Oklahoma. Carapace elongate, dorsal outline broadly arched ; ventral margin straight, anterior and posterior terminations well below midheight; the postero- and an- terodorsal slopes are a regular continua- tion of the dorsal arch, the former some- what steeper; posterior beak narrow, rounded; overlap moderate on dorsal and midventral margins, slight or lack- ing at other points. Length, 1.26 mm; height, 0.56 mm; width, 0.40 mm. B. lunata is marked by the extremely low position of the terminations in the lateral view. Millersville zone, locality 90. Bairdia menardensis Harlton Plate 2, figures 32-35 Bairdia menardensis Harlton, 1929, Texas Univ. Bull. 2901, p. 158, pi. 4, figs, la-d; Canyon series, Texas. — Delo, 1930, Jour. Paleontology, vol. 4, p. 164, pi. 12, fig. 16; Graham group, Texas. — ?Brad- field, 1935, Bull. Am. Paleontology, vol. 22, p. 85, pi. 6, figs. 4, 5, 9; Hoxbar group, Oklahoma. Carapace tumid, dorsal margin highly arched, ventral margin straight or slightly convex in central portion, rising in broad symmetrical curves to meet terminations ; posterodorsal slope straight except lower third, where it be- comes distinctly concave, resulting in a decidedly upturned beak; anterodorsal slope slightly concave; overlap great along entire dorsal margin, faint along venter except in the midportion where it is moderate ; surface finely granulose to punctate. Length, 1.32 mm; height, 0.77 mm; width, 0.63 mm. B. menardensis is characterized by its great tumidity as compared to its very acuminate terminations as seen in dorsal view, and by its distinctly upturned beak. 48 PENNSYLVANIA!! OSTRACODES Oak Grove and (runlet zones. Localities 14, 62. Bairdia menardvillensis Earlton Plate 2, figures 38-42; plate 4, figures 9-11 Bairdia marginata Harlton, 1929 (not Bosquet), Texas Univ. Bull. 2901, p. 158, pi. 4, fig. 2; Canyon series, Texas. Bairdia menardvillensis Harlton, 1931, Jour. Paleontology, vol. 5, p. 163. Carapace Large, tumid, dorsal margin arched, ventral margin concave; postero- dorsal slope Long, straight, steep, slightly upturned near beak; anterodorsal slope straighl ; overlap greatest along dorsal and midventral articulation; posterior beak acuminate and well below mid- height; anterior end broad, rounded; a sudden lessening of thickness of cara- pace in the posteroventral angle gives appearance of a shallow furrow; surface finely granulose. Length, 1.54 mm; height, 0.95 mm; width, 0.61 mm. 11. menardvillensis appears quite simi- lar to B. menardensis Harlton. How- ever, the following differences in the former are noted: greatest tumidity posterior; more elongate centrodorsa! margin; broader and less acuminate an- terior end and a somewhat larger form ratio. Gimlet and Exline zones, localities 62, 66. Bairdia aioxstrabillis Cooper, n. sp. Plate 3, figures 5-10 Carapace large, tumid, subrhomboi- dal; dorsal margin arched, antero- and posterodorsal slopes steep ; ventral mar- gin straight, and marked by sharp, thin, but conspicuous ridge parallel to venter ; dorsal articulation forms straight lines, giving upper part of carapace an ap- pearance of angularity, overlap conspic- uous along these margins ; posterior beak short, acuminate, and slightly upturned ; both ends slightly below midheight ; sur- face smooth to granulose. Length (pi. 2, figs. 38-42), 1.26 mm; height, 0.72 mm ; width, 0.52 mm. This species may be easily recognized by the sharp thin ridge parallel to the venter. Brereton to Shumway /ones. Localities 40, 81, 83, 84, M, 88, 93, 102, 109. Bairdia oklahomaensis Barlton Plate 3, figures 15-20 Bairdia oklahomaensis Harlton, 1927, Jour. Paleontology, yol. l. p. 209, pi. 33, fig. 7; Glenn Formation, Oklahoma. — Harlton, 1929, Univ. Texas Hull. 2901, p. 156, pi. 3. figs. 5a, b; Canyon series, Texas. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 69, pi. 5, figs. 8a, b; Wewoka- Holdenville f o r m a t i o n s, Oklahoma. — Coryell and Billings, 1932, Am. Mid- land Naturalist, vol. 13, p. 172, pi. 17, fig. .". : Way la nd shale. Texas. — Coryell and Sample. 1 932, idem., p. 264, pi. 25, fig. 9; East Mountain shale, Texas. — Brad- field. 1935. Hull. Am. Paleontology, vol. 22, p. 85, pi. 5. figs. 9a, b; Hoxbar group, Oklahoma. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 41, pi. 4, figs. 6, 7; Upper Missouri series, Nebraska. Bairdia auricula Knight, 1928, Jour. Paleon- tology, vol. 2, p. 319, pi. 43, figs. 3a, b; upper Ft. Scott formation, Missouri. —Coryell and Sample, 1932, Am. Mid- land Naturalist, vol. 13, p. 263, pi. 25, fig. 6; East Mountain shale, Texas. — War- thin, 1930, Oklahoma Geol. Survey Bull. 53, p. 68, pi. 5, figs. 7a, b; Wetunka-Hold- enville formations, Oklahoma. Bairdia dornickhillensis Harlton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 268, pi. 2, figs. 12a, b; Dornick Hills group, Okla- homa. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 78, pi. 5, figs. 3a, b; Deese group, Oklahoma. Bairdia seminalis, Payne, 1937 (not Knight, 1928), Jour. Paleontology, vol. 11, p. 285, pi. 39, figs. 9a, b; Hayden Branch forma- tion, Indiana. Carapace short, tumid, dorsal margin acutely arched, ventral margin straight, except anteriorally and very near poste- rior end; shell flat to slightly depressed in centrodorsal half; overlap strongest on anterodorsal slope and midventral margin; overlap on posterodorsal slope interrupted by a swelling of carapace in the midportion of the slope ; beak short, well below midheight ; anterior termina- tion well above midheight; surface granulose. BAIRDIIDAE 49 Length, 1.36 mm; height, 0.85 mm; width, 0.61 mm. B. oklahomaensis is easily recognized by the acutely arched dorsum, the swell- ing on the posterodorsal slope, and the point of anterior termination well above midheight. The long range of this species as re- ported by its occurrence in the Midcon- tinent is reflected in its Illinois distri- bution in various zones from the Fulda to the Macoupin, localities 1, 3, 8, 10, 13, 19, 21, 29, 30, 32, 38, 40, 54, 55, 58, 60, 64, 67, 69, 73, 86. Bairdia pennata Coryell and Sample Plate 3, figures 1-4; plate 4, figures 3, 4 Bairdia angulata Coryell and Sample, 1932 (not Brady, 1870), Am. Midland Natur- alist, vol. 13, p. 262, pi. 25, fig. 16; East Mountain shale, Texas. Bairdia pennata Coryell and Sample, 1933, idem., vol. 14, p. 187. Carapace elongate, somewhat tumid, dorsal margin arched; posterodorsal slope long and gently inclined; beak long, narrow, acuminate and below mid- height ; anterior end rounded, somewhat narrow, above midheight; ventral mar- gin straight; overlap moderate around entire carapace. Length (pi. 3, figs. 1, 2), 0.87 mm; height, 0.46 mm ; width, 0.40 mm. Ferdinand to Shoal Creek zones, lo- calities 2, 5, 13, 21, 77. Bairdia peracuta Warthin Plate 3, figures 11, 12; plate 4, figures 1, 2 Bairdia peracuta Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 71, pi. 6, figs. 2a, b; Holdenville formation, Oklahoma. — Coryell and Osorio, 1932, Am. Midland Naturalist, vol. 13, p. 33; Nowata shale, Oklahoma. Carapace elongate, acuminate ; dorsal margin rounded; ventral margin regu- larly convex to ends ; posterodorsal slope steep in upper two-thirds, acutely con- cave in lower third, making the beak very slender with a slightly upturned appearance ; anterior end acuminate ; overlap greatest along anterodorsal mar- gin, least along venter; surface distinct- ly granulose. Length (pi. 3, figs. 11, 12), 1.34 mm; height, 0.62 mm ; width, 0.49 mm. B. peracuta appears to have a more acuminate appearance both in dorsal and lateral views, than most any other Pennsylvanian species. B. pennata Coryell and Sample from the Liverpool resembles this species but is slightly more tumid and possesses a distinct dor- sal overlap not present in B. peracuta. Liverpool to Gimlet zones, localities 17, 38, 53, 54, 60. Bairdia pinnula Coryell and Booth Plate 3, figures 13, 14 Bairdia pinnula Coryell and Booth, 1933, Am. Midland Naturalist, vol. 14, p. 263, pi. 3, fig. 14; Wayland shale, Texas. Carapace rather small, dorsal margin arched, ventral margin straight ; ante- rior end rounded, termination at mid- height; posterodorsal slope low, slightly convex ; beak wide, acuminate, and slight- ly below midheight; greatest overlap along anterior half of dorsum; surface smooth. Length, 0.95 mm; height, 0.59 mm; width, 0.44 mm. B. pinnula differs from B. seminalis Knight and B. angusta n. sp. in its long, low posterodorsal slope and is less elon- gate than B. demissa n. sp. The very large overlap on the anterodorsal slope is also characteristic. Shumway zone, locality 109. Bairdia pompilioides Harlton Plate 3, figures 39-43 Bairdia pompilioides Harlton, 1928, Jour. Paleontology, vol. 2, p. 140, pi. 21, fig. 13; Hoxbar group, Oklahoma. — Harl- ton, 1929, Texas Univ. Bull. 2901, p. 154, pi. 2, fig. 7; pi. 3, fig. 8; Canyon group, Texas. — Coryell and Osorio, 1932, Am. Midland Naturalist, vol. 13, p. 33; No- wata shale, Oklahoma. — Kellett, 1934, Jour. Paleontology, vol. 8, p. 130, pi. 16, figs. 2-4; Stanton limestone to Wreford formation, Kansas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 87, pi. 6, figs. 5a, b; Hoxbar group, Okla- 50 PENNSYLVANIA!! OSTRACODES homa. — Payne, 1937, Jour. Paleontol- ogy, vol. 11, p. 2S4, pi. 39, figs. 7, 8; Hayden Branch formation. Indiana. — Scott and Borger, 1941. idem., vol. 15, p. 356, pi. 49, figs. 13, 14; Macoupin formation, Illinois. Bairdia grahamensis. Warthin, 1930, Okla- homa Geol. Survey Bull. 53, p. 70, pi. 5, figs. 12a, b; Holdenville formation, Okla- homa. Bairdia subcitriformis Knight, 1928, Jour. Paleontology, vol. 2, p. 322, pi. 43, figs. 5a, b; Pawnee limestone, Missouri. Carapace large, dorsal margin highly arched, somewhat flat in centrodorsal region, steepening toward ends; postero- dorsal slope short and very steep (ca. 5o : ). beak very low. thin, acuminate; anterior slope straight to slightly con- cave; anterior end high, acuminate; ventral margin convex ; greatest tumid- ity central, decreasing rapidly toward ends ; greatest overlap along: centro- and anterodorsal articulation, least along antero- and posteroventral margins; sur- face granulose. Length, 1.68 mm; height, 0.82 mm; width, 0.60 mm. Shoal Creek limestone to Greenup zones, localities 77. 90. 107. 108, 110,. 112. 113. 114. Bairdia regularis Cooper, n. sp. Plate 3, figures 30-32 Carapace large, elongate, dorsal mar- gin broadly arched, curvature merging smoothly with slightly convex antero- and posterodorsal slopes ; the latter merges with short, very slightly upturn- ed beak almost without producing con- cavity in outline ; ventral margin slight- ly concave ; overlap prominent along centroventral and dorsal margins; ter- minations below niidheight ; surface finely granulose. Length. 1.67 mm; height. 0.90 mm; width. 0.63 mm. B. regularis is somewhat similar to B. summa Coryell and Billings and some of the various forms described as B. pleoeia Reuss. being intermediate between these species in form ratio. It is larger and more elongate than the \Vayland species. It is almost bilaterally symmetrical due to the very short, wide beak. The up- turned beak and position of greatest height posterior distinguishes it from B. hoffmanae Kellett. Exline zone, locality 66. Bairdia cf. B. rhomboidea Kirkby Plate 3, figures 25, 26 Bairdia rhomboidea Kirkby, 1858, Annals and Mag. Nat. History, ser. 3, vol. 2, p. 433, pi. 11, fig. 3; Magnesian limestone, England. — Jones and Kirkby, 1860, Tyneside Nat. Field Club Trans., vol. 4, p. 149, pi. 10, fig. 3; Magnesian lime- stone, England. Carapace elongate, subrhomboid, dor- sal margin low and broadly arched; posterodorsal slope low, but steeper than anterior slope ; ventral margin broadly convex, the regular curvature becoming more acute near anterior end, but no marked upward swing on posterior; beak very long and below niidheight ; anterior end acuminate with termination above niidheight ; overlap moderate on dorsal margin ; negligible on venter. Length, 1.34 mm; height, 0.64 mm; width. 0.42 mm. The Illinois form seems to be more closely related to B. rhomboidea from the Permian of England than to any other known species. In the English form the posterior slopes appear sym- metrical about a horizontal line through the center of the carapace, while in the Illinois form the posterodorsal slope is somewhat shorter and steeper. Shumway zone, locality 109. Bairdia schaurothiaxa Kirkby Plate 3, figures 21-24 Bairdia schaurothiana Kirkby, 1858, Annals and Mag. Nat. History, p. 329, pi. 10, fig. 14; Permian, British Isles. —Jones and Kirkby, 1860, Tyneside Nat. Field Club Trans., vol. 4, p. 147, pi. 9, fig. 14; Permian, British Isles. Cythere schaurothiana Geinitz, 1861, Die anamalischen Uberreste der Dyas, vol. 1 of "Dyas oder die Zechsteinformation und das Rothliegende," Leipsig, p. 36; Permian, Germany. BAIRDIIDAE 51 Cythere (Bairdia) schaurothiana Kirkby, 1862, Annals and Mag. Nat. History, ser. 3, vol. 10, p. 203, pi. 4, figs. 1-4, 11-12; Carboniferous and Permian, British Isles. Carapace very elongate, thin, dorsal margin straight or slightly convex in central portion, ventral margin slightly concave, resulting in almost parallel up- per and lower margins; posterodorsal slope short and steep ; anterodorsal slope long and low, merging into the rounded anterior end, termination at midheight; posterior beak about midheight, short and broad; overlap moderate along dor- sal and centroventral line of articula- tion, but slight or wanting entirely at other points ; surface smooth. Length, 1.57 mm; height, 0.77 mm; width, 0.58 mm. B. schaurothiana, occurring well down in the Illinois Pennsylvanian section, ap- pears to be the same as the species de- scribed from the Permian and Carboni- ferous of the British Isles. Listed in synonomy with B. hisingeri by Bassler and Kellett (1934, p. 173), it appears to be sufficiently different from those from the Carboniferous limestone and Calci- ferous sandstone (Lower Carboniferous, probably Chester) to be considered as a distinct species. It is more elongate than most species of Bairdia with a form ratio of more than 2.2. B. schaurothiana is characterized by a straight dorsal margin, a short, steep posterodorsal slope, a less acute anterodorsal slope, a concave centroventral margin, merging into a broad upward swing which meets the terminations at about midheight. Seville zone, locality 4. Bairdia scholli Coryell and Booth Plate 3, figures 33, 34 Bairdia scholli Coryell and Booth, 1933, Am. Midland Naturalist, vol. 14, p. 264, pi. 4, figs. 3, 4; Wayland shale, Texas. Carapace medium sized, moderately tumid, tumidity carrying well out to ends, resulting in lens-shaped dorsal out- line; dorsum asymmetrically arched, greatest height anterior, sloping gradu- ally back toward posterodorsal angle, where posterodorsal slope increases the angle perceptibly ; centroventral margin straight, swings upward smoothly to meet the ends; posterior beak short, wide, below midheight; anterior end rounded, terminated above midheight ; anterodorsal and centroventral overlap prominent, surface smooth to granulose. Length, 1.13 mm; height, 0.62 mm; width, 0.51 mm. Resembles B. demissa n. sp. in the position of greatest height but differs in the presence of bulge and angulation in the posterodorsal region. Little Vermilion to Woodbury zones, localities 103, 110, 115. Bairdia seminalis Knight Plate 3, figures 27-29 Bairdia seminalis Knight, 1928, Jour. Pale- ontology, vol. 2, p. 320, pi. 43, figs. 2a-d; upper Ft. Scott and Pawnee formations, Missouri. — Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 262, pi. 25, fig. 14; Mineral Wells formation, Texas. —Kellett, 1934, Jour. Paleon- tology, vol. 8, p. 127, pi. 15, figs. 2a-c; Stanton limestone to Neva limestone, Kansas. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 40, pi. 4, fig. 3; Westerville limestone to Stanton forma- tion, upper Missouri series, Nebraska. Not Bairdia seminalis, Coryell and Rozanski, 1942, Jour. Paleontology, vol. 16, p. 146, pi. 24, fig. 1. Bairdia blakei, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 84, pi. 6, figs, la, b; Hoxbar group, Oklahoma. Bairda crassa, Delo, 1930 (not Harlton), Jour. Paleontology, vol. 4, p. 164, pi. 12, fig. 15; Graham group, Texas. — Delo, 1931, Washington Univ. Studies, n. ser. Sci. and Tech., no. 5, p. 49, pi. 4, fig. 9; Pennsylvanian, Kansas. Bairdia samplei Coryell and Booth, 1933, Am. Midland Naturalist, vol. 14, p. 264, pi. 3, figs. 12, 13; Graham formation, Texas. Bairdia tumida Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 21, pi. 2, figs. 3a-c; Garrison shale, Nebraska. Carapace small, ovate, somewhat tumid ; dorsal and ventral margins semi- circular, giving SURVEY HDR^ V JUN " 19&1 52 PENNSYLVANIAN OSTRACODES lateral view ; postero- and anterodorsal slopes approximately equal ; posterior beak short, wide, and slightly below mid- height ; overlap pronounced on all mar- gins, but least on postero- and antero- ventral articulation. Length, 1.05 mm; height, 0.91 mm; width, 0.48 mm. B. seminalis is characterized by a com- plete lack of angularity marginal or be- tween lines of articulation, as viewed from lateral and dorsal positions. It is differentiated from B. blakei Harlton by the very pronounced dorsal overlap. Pokeberry to Woodbury zones, locali- ties 53, 62, 70, 75, 76, 81, 90, 93, 99, 109, 112, 114, 115. Bairdia spinosa Cooper, n. sp. Plate 3, figures 44-46 Carapace small, tumid, rather short; dorsal margin convex, ventral margin straight, anterior end rounded ; posterior termination short, acuminate, to rather high ; junction of anterior and dorsal margins angular ; posterodorsal slope short, very steep ; overlap moderate and rather uniform around all margins ex- cept anterodorsal, where it is wanting; posterior two-thirds of hinge line in- cised; surface granular, ornamented by a large number of short, wart-like spines scattered promiscuously over the shell surface. Length, 0.80 mm ; height, 0.51 mm ; width, 0.44 mm. B. spinosa is readily differentiated by the peculiar wart-like spines, and differs from B. wordensis Hamilton (1942, p. 716) in that the spines appear over the entire shell surfaces as well as along the dorsum. Shoal Creek zone, locality 77. Bairdia summa Coryell and Billings Plate 3, figures 35, 36 Bairdia summa Coryell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 170, pi. 17, fig. 1; Wayland shale, Texas. Texas. Carapace large, dorsal margin strong- ly bowed, ventral margin straight in central portion, curving upward at ends ; beak short, blunt, well below mid- height ; overlap very slight along ventral margin and anterior end, very pro- nounced along dorsum and posterodorsal slope, greatest in centrodorsal region ; greatest height central; surface smooth to granulose. Length, 1.44 mm; height, 0.77 mm; width, 0.54 mm. B. summa is distinguished by its strong, broadly arched dorsum and by its large, elongate carapace (form ratio, 1.84). "Centralia" zone, locality 82. Bairdia symmetrica Cooper, n. sp. Plate 3, figures 37, 38 Carapace elongate, tenuous, symmetri- cal in lateral and dorsal views; dorsal margin broadly arched, merging smooth- ly into the equally inclined antero- and posterodorsal slopes; ventral margin straight in center, swinging upward gradually to meet the ends ; anterior ter- mination at midheight and slightly above posterior beak; posterior beak sharply acuminate ; overlap prominent along dorsal margin, absent along ven- ter; surface finely granulose. Length, 1.0 mm; height, 0.48 mm; width, 0.36 mm. The lateral outline of B. symmetrica is similar to B. galei Croneis and Thur- man but lacks the concavity in the cen- troventral margin, and lacks the strong- ly curved ventral extremities fo B. gra- hamensis Harlton. The dorsal margin is more acutely arched and the anterior end lower than B. legumen Jones and Kirkby. Trivoli zone, locality 70. Bairdia verwiebei Kellett Plate 4, figures 7, 8 Bairdia venoiebei Kellett, 1934, Jour. Pale- ontology, vol. 8, p. 129, pi. 17, figs. 2a-c; Winfield to Wreford, Kansas. Carapace elongate, thin, dorsal margin flattened, ventral margin straight, paral- lel to dorsum ; anterodorsal slope but BAIBDIIDAE 53 little less steep than posterior; beak be- low midheight, fairly long, narrow, bluntly acuminate ; anterior end narrow, rounded, and at midheight; overlap pronounced along dorsum, lacking on venter. Length, 1.05 mm; height, 0.51 mm; width, 0.32 mm. The first occurrence of this species be- low the Permian is in the younger beds of the Illinois Pennsylvanian, the Shum- way zone, localities 109, 112. Bairdia whitesidei Bradfield Plate 4, figures 12-15 Bairdia whitesidei Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 82, pi. 5, figs. 10a, b; Deese group, Oklahoma. Carapace large, elongate, dorsal mar- gin arched, anterior and posterodorsal slopes slightly concave, about equal; ventral margin convex ; overlap greatest in centrodorsal and centroventral mar- gins; greatest tumidity central, decreas- ing abruptly toward each end, giving terminations an acuminate appearance in dorsal view ; posterior beak long, mod- erately wide ; anterior end rounded ; sur- face finely granulose. Length, 1.72 mm; height, 0.97 mm; width, 0.87 mm. B. ivhitesidei resembles B. summa Cor- yell and Billings but is more acuminate in dorsal view. The great overlap along the centroventral articulation is char- acteristic. Seville to Brereton zones, localities 6, 10, 12, 38. Genus Bairdiacypris Bradfield, 1935 Bairdiacypris acuminata Cooper, n. sp. Plate 4, figures 24, 25 Carapace elongate, lateral outline lens- shaped; dorsal margin arched, postero- dorsal slope convex, joining dorsal mar- gin with little interruption of regular curvature of the latter; ventral margin concave ; anterior end broadly rounded ; posterior end quite acuminate, but sharply rounded, and depressed well be- low midheight; overlap on dorsum and posterodorsal slope wide and uniform, thin on ventral margin. Length, 1.12 mm ; height, 0.52 mm ; width, 0.40 mm. B. acuminata may be distinguished by its unusually narrow posterior ter- mination and by the slightly convex posterodorsal slope. Gimlet to Woodbury zones, localities 62, 81, 88, 115. Bairdiacypris ardua Cooper, n. sp. Plate 4, figures 18, 19 Carapace elongate; lateral outline sublenticular ; dorsal margin convex, but rather flat, ventral margin slightly con- cave ; posterodorsal margin steep, ab- ruptly joining dorsal margin ; anterior end broadly rounded, posterior narrow, rounded, and terminated about mid- height ; overlap moderate along dorsal and centroventral margins, slight on other margins. Length, 1.10 mm; height, 0.49 mm; width, 0.36 mm. B. ardua may be recognized by its steep abrupt posterodorsal slope and by the unusually high position of the poste- rior termination. Millersville and Shumway zones, lo- calities 90, 109, 112. Bairdiacypris deloi Bradfield Plate 4, figures 22, 23 Bairdiacypris deloi Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 93, pi. 7, figs. 8a, b; 9a, b; Hoxbar group, Oklahoma. Carapace ovate, lenticular in dorsal outline ; dorsal margin arched ; ventral margin concave ; ends rounded, posterior acuminate and terminated below mid- height; dorsal overlap moderate in cen- ter thinning toward anterior end and down fairly long, straight posterodorsal slope ; ventral overlap narrow in center decreasing to nothing at each end. Length, 1.23 mm; height, 0.51 mm; width, 0.42 mm. "Centralia" zone, locality 82. 54 PENNSYLVANIAN OSTRACODES Bairdiacypris haydenbrachensis (Payne) Plate 4, figures 20, 21 Bythocypris haydenbrauchensis Payne, 1937, Jour. Paleontology, vol. 11, p. 285, pi. 40, figs, la, b; Hayden Branch formation, Indiana. Carapace sublenticular in lateral out- line; dorsal margin arched, somewhat flat in central portion, curving: down- ward at unequal angles toward some- what acuminate ends, both terminated below midheight ; ventral margin con- cave; overlap moderately wide, fairly uniform around all margins, widest in centrodorsal area, narrowest around ends. Length, 1.22 mm; height, 0.55 mm; width. 0.48 mm. Millersville zone, locality 90. Bairdiacypris xebraskensis (Upson) Plate 4. figures 28, 29 Bairdia nebraskensis Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 18, pi. 1, figs. 6a, b; Wreford formation, Nebraska. Bairdia subelongata. Harlton, 1929 (not Jones and Kirkby), Texas Univ. Bull. 2901, p. 157, pi. 3, figs. 6a-d; Canyon series, Texas. Bairdia rogatzi Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 264, pi. 25, fig. 7; East Mountain shale, Texas. Bairdia acetalata, Upson, 1933 (not Coryell and Billings), Nebraska Geol. Survey Bull. 8, p. 17, pi. 1, fig. 5a; Garrison shale, Nebraska. Bairdia hoxbarensis. Keilett, 1934 (not Harl- ton). Jour. Paleontology, vol. 8, p. 131, pi. 16, figs. 5a-c; Topeka to Wreford formations, Kansas. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 40, pi. 4, fig. 8; Wyandotte to Stanton form- ation, Nebraska. Bairdia glennensis, Bradfield, 1935 (not Harlton), Bull. Am. Paleontology, vol. 22, p. 81, pi. 5, figs. 12a, b; Deese group, Oklahoma. Carapace elongate, semieliptical in lat- eral outline; dorsal margin strongly con- vex, ventral margin concave ; anterior end broadly rounded, posterior also rounded but more acuminate and depressed below midheight ; posterodorsal slope short and straight; overlap fairly broad along dor- sum, narrow in centroventral region and faint or lacking around ends. Length, 1.26 mm; height, 0.54 mm; width. 0.38 mm. Most of the species listed in the synonomy were considered 1o be r>9 / Wx- x NEWTON 1 ^ > - * WEWOKA D OTHER ILLINOIS FORMATIONS . ' *^/f ?7 O 3 DESCRIBED "SPECIES" /_ Q fi >"^ " (SEE EXPLANATION BELOW) 1? 3^ * "" ^ / ^\\ / >^^ 1 — — -^ • N \ ^^ 1 X ^" X| / / X >*^ ! / 1 1 1 1 1 1 1 — ,2 .6 .7 LENGTH (mm.) .9 1,0 I.I Fig. 33 — Graph of length-height dimensions of Sulcella. 1, 8. warthini Coryell and Sample; 2, 8. edmistoni (Harris and Lalicker) ; 3, 8. texana (Warthin) ; 4, 8. celsa Cooper; 5, 8. ovata Cooper; 6, 8. harrisi Bradfield; 7, 8. Tiarrisi and 8. texana, Harris and Lalicker; 8, 8. sulcata Coryell and Sample, stated measure- ment of holotype; 9, measured figure of holotype at stated magnification (com- pare with 8). ogy, vol. 9, p. 149. — Johnson, 1936, Ne- braska Geol. Survey Paper 11, p. 47, pi. 5, figs. 7-9; Chanute and Kanwacka shales, Nebraska. Sulcella warthini Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 275, pi. 26, fig. 17; East Mountain shale, Texas. Sulcella Tiarrisi Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 134, pi. 12, figs. 9-106; Dornick Hills group, Oklahoma. Carapace elongate, semielliptical in lateral outline; dorsal and ventral mar- gins convex ; anterior end symmetrically rounded ; posterior end rounded to trun- cate on anteroventral margin ; overlap prominent, greatest in centroventral and anterodorsal margins, narrower around ends and posterodorsal margin ; anterior end of left valve bordered by a low, nar- row ridge; a small, deep pit, shallower on dorsal margin, is located slightly an- terior to and well above midpoint; on left valve this pit adjoins a slightly flat- tened area of the anterodorsal portion of the valve, giving the pit a somewhat sulcate appearance; this flat area is ab- sent on right valve, the pit being equally well-defined on all margins; greatest height posterior, greatest length above midheight; surface smooth. Female: length, 1.0 mm; height, 0.54 mm ; thickness, 0.42 mm. Male : length, 0.95 mm ; height, 0.51 mm; thickness, 0.37 mm. Umisually good collections from the Newton of Illinois and the Wewoka of Oklahoma contain a large number of specimens of various sizes, which when their proportions are plotted, show the existence of at least six instars. The described Pennsylvanian species are closely related to four of these instars as follows: the genoholotype, 8. sulcata 17 Coryell and Sample is an adult form (M) ; 8. harrisi Bradfield (from the Hoxbar) and 8. texana (Harris and La- licker) , instar M — 1 ; S. harrisi Bradfield from the Dornick Hills), instar M — 2; 8. texana Warthin, 8. warthini Coryell u Coryell and Sample's (1932, pi. 26, fig. 18) figure of the genoholotype does not have either pit or sulcus, and does not correspond to the dimensions given in the description. However, a photograph of the type, fur- nished by the senior author, does have the pit as described in the original paper, but it also is at vari- ance with the published dimensions. PENNSYLVANIAN 08TRAC0DE8 and Sample, and 8. edmistoni (Harris and Lalicker), instar M — 4. In 1929 Harlton described Jonesina texana from the East Mountain shale, Menard County, Texas, which is now referred to Knoxina (Coryell and Ro- gatz, 1932). Later Warthin (1930) er- roneously identified a specimen from the Wewoka formation of Oklahoma as J. texana (Harlton). Coryell and Sample considered Warthin 's Wewoka specimen identical with one of their new species of Sulcella, namely 8. warthini. In the same year Harris and Lalicker describ- ed Sansabelloides texana (Warthin) from the Francis formation in Okla- homa. Bradfield (1935) described Sul- cella harrisi from the Dornick Hills group, designating as the holotype Har- ris and Lalicker 's Francis specimen, but figuring two specimens each of which ap- pears to be a distinct species. Kellett (1935, p. 149) after a study of the size and shape variations between young and old specimens, listed Jonesina texana, Warthin and Sansabelloides texana Harris and Lalicker as S3^noii3 T ms of Sidcella ivarthini. Finally Johnson placed all of these species in synonomy with 8. sulcata. In the Midcontinent the beds from which "species" of Sidcella have been described, range in age from the upper Dornick Hills group (lower Atoka series) to the Kanwacka shale (middle Virgil series). In Illinois 8. sulcata ranges from the Seville to the Newton cyclo- them, localities 6, 14, 16, 26, 62, 82, 107, 112. Family Darwinulidae Brady and Robertson, 1872 Genus Darwinula Jones, 1885 Darwinula pungens (Jones and Kirkby) Plate 10, figures 39, 40 Cythere pungens Jones and Kirkby, 1867, Geol. Soc. Glasgow Trans, vol. 2, p. 222. Cythere (DarwineUaf) pungens Jones, 1884, Berwickshire Nat. Field Club Proc, vol. 10, pp. 319, 325. Carbonia pungens Jones and Kirkby, 1879, Annals and Mag. Nat. Hisory, ser. 5, vol. 4, p. 37, pi. 3, figs. 21-23. —Jones and Kirkby, 1890, Manchester Geol. Soc. Trans., vol. 21, pt. 3, p. 138, pi., figs. 1, 2a, b; Coal Measures, England and Scotland. — Pruvost, 1911, Soc. geol. Nord Annales, vol. 40, p. 71, pi. 2, figs. 13, 14; Coal Measures, Prance. Carbonita pungens Bassler and Kellett, 1934, Geol. Soc. Am. Spec. Papers 1, p. 239. Darwinula hollandi Scott, 1944, Jour. Paleon- tology, vol. 18, p. 146, pi. 24, figs. 6-8; Nineveh limestone, Pennsylvania. Carapace elongate, slender ; lateral outline semiovate ; dorsal margin broad- ly convex ; ventral margin straight ; ends rounded, posterior very broad, anterior acuminate ; hinge line nearly straight, the valves meeting evenly ; overlap greatest around ends, decreasing along venter where the line of junction is curved in anterior third ; greatest height t and thickness posterior ; surface smooth. Length, 0.76 mm ; height, 0.35 mm ; width, 0.30 mm. This species has been removed from Carbonita because of the differences in hinge structure and character of over- lap. D. hollandi is thought to be an im- mature moult of this species, inasmuch as it has an identical form ratio. Summum zone, locality 27. Family Drepanellidae Swartz, 1936 Genus Cornigella Warthin, 1930 CORNIGELLA TUBERCULOSPINOSA (Jones and Kirkby) Plate 11, figures 16-23 Beyrichia tuberculo-spinosa Jones and Kirk- by, 1886, Annals and Mag. Nat. History, ser. 5. vol. 18, p. 258, pi. 8, figs. 7, 8. — Ulrich and Bassler, 1908, U. S. Nat. Mus. Proc, vol. 35, p. 321, pi. 42, figs. 21. 22; Carboniferous of Great Britain. Ulrichia tuberculo-spinosa Ulrich, 1891, Cin- cinnati Soc. Nat. History Jour. vol. 13. p. 203. liollina tuberculospinosa Latham, 1932, Roy. Soc. Edinburg Trans., vol. 57, pt. 2, p. 361. Cornigella tuberculospinosa Warthin, 1930 Oklahoma Geol. Survey Bull. 53, p. 59. HEALDIIDAE 79 Comigella longispina Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 254, pi. 24, fig. 12; East Mountain shale, Texas. fCornigella pushmatahensis Harlton, 1933, Jour. Paleontology, vol. 7, p. 19, pi. 7, fig. 2; Johns Valley shale, Oklahoma. Comigella minuta Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 59, pi. 4, figs. 7a-c; Wewoka formation, Oklahoma. —Coryell and Sample, 1932, Am. Mid- land Naturalist, vol. 13, p. 253, pi. 24, fig. 6; East Mountain shale, Texas. —Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 18, pi. 1, figs. 15, 16; Cha- nute shale, Nebraska. Carapace small, subquadrate, dorsal margin straight, ventral margin convex ; greatest height posterior, producing dis- tinct retral swing in lateral view ; valves equal, ornamented by coarse reticulation and a variable number (usually 6 to 8) of short rounded nodes of considerable diameter, one or more of which (nearest hinge line) may be elongated to form a thick tapering spine. Length (figs. 21-23), 0.50 mm; height, 0.30 mm ; width, 0.15 mm. There is considerable variation within species of this genus with regard to the number of spines or nodes. Some indi- viduals have no spines and many have less than 8 nodes whereas others have as many as two spines extending above the hinge line, although the anterior one is always the longer. Also some specimens from the same sample seem more elon- gate than others. Summum to Newton zones, localities 26, 62, 66, 79, 82, 112. Family Glyptopleuridae Girty, 1910 Genus Glyptopleura Girty, 1910 Glyptopleura coryelli Harlton Plate 10, figures 43-45 Glyptopleura spinosa, Harlton, 1929, Texas Univ. Bull. 2901, p. 148, pi. 1, fig. 18, Canyon group, Texas. — Delo, 1930, Jour. Paleontology, vol. 4, p. 162, pi. 12, fig. 12. —Delo, 1931, Washington Univ. (St. Louis) Studies, new ser., Sci. and Tech. no. 5, p. 44, pi. 4, fig. 4. Glyptopleura coryelli Harlton, in Coryell and Brackmier, 1931, Am. Midland Natural- ist, vol. 12, p. 513, pi. 2, fig. 18. —John- son, 1936, Nebraska Geol. Survey Paper 11, p. 36, pi. 3, fig. 15; Stanton forma- tion, Nebraska. Carapace subquadrate, tumid, hinge line straight; ventral margin convex, though sometimes slightly flattened in midportion ; ribs wide, prominent, broad, straight to sinuous, inclined to- ward anteroventral corner at a fairly low angle ; rib next above pit bifurcates just in front of pit into two short equally prominent portions; short rib is located just back of pit, another is located in the anterodorsal angle and a third short acuminate rib borders the ventral mar- gin and equals about half the length of the shell ; all ribs seem to bend down- ward at the ends to merge with the shell surface, also bending upward and down- ward as if gathered together into a bundle at each end of the shell ; circular pit anterior of center is located below first rib. Length, 0.95 mm ; height, 0.57 mm ; width, 0.54 mm. Gimlet to Millersville zones, localities 57, 89, 90. Glyptopleura irregularis Delo Plate 10, figures 41, 42 Glyptopleura irregularis Delo, 1931, Wash- ington Univ. (St. Louis) Studies, new ser., Sci. and Tech. no. 5, p. 44, pi. 4, fig. 5. Carapace somewhat elongate, hinge line straight, ventral margin convex; ends rounded; ribs few, straight, cross- ing diagonally from posterodorsal to anteroventral portions, ending abruptly posteriorly with ends raised above shell surface to form spine-like terminations; pit small, circular, fairly deep, anterior to center. Length, 0.77 mm ; height, 0. 46 ; width, 0.34 mm. Millersville zone, locality 90. Family Healdiidae Harlton, 1933 Genus Healdia Koundy, 1926 Healdia alba Coryell and Billings Plate 11, figures 24, 25 Healdia alba Coryell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 178, pi. 18, fig. 13; Wayland shale, Texas. —Cor- 80 PENNSYLVANIAN 0STRAC0DK8 yell and Sample, 1932, idem, p. 270, pi. 26, fig. 3; East Mountain shale, Texas. — Bradfield, 1935, Bull. Am. Paleontol- ogy, vol. 22, p. 115, pi. 10, figs. 3a, b; Hoxbar group, Oklahoma. Carapace short, tumid, ovate in lateral outline; dorsal margin strongly convex, ventral margin nearly straight ; ends about equally rounded; overlap slight; posterodorsal truncation slightly con- vex; spines small, widely spaced, with a strong lateral deflection ; greatest height slightly anterior, greatest thickness posterior. Length, 0.56 mm ; height, 0.37 mm ; width, 0.29 mm. The spines of H. alba rise almost 90° from the surface of the shell as contrast- ed to the strong posterior deflection of the spines on most species of Healdia. LaSalle zone, locality 92. Healdia asper Cooper n. sp. Plate 11, figures 41, 42 Carapace semiovate, dorsal margin strongly arched, ventral margin slightly concave ; ends rounded, anterior some- what flattened; overlap broad, variable, being least around ends and greatest along posterodorsal and posteroventral margins; spines large, slightly curved, flaring at base, and closely spaced ; bases of spines joined by short pronounced carina forming a prominent shoulder; greatest height slightly back of center, greatest thickness near posterior end. Length, 0.52 mm; height, 0.36 mm; width, 0.27 mm. St. David zone, locality 30. Healdia aspinosa Cooper, n. sp. Plate 11, figures 39, 40 Carapace elongate, dorsal margin broadly arched, ventral margin slightly convex; ends rounded, anterior end somewhat flattened in midportion; pos- terodorsal slope straight to slightly con- cave; overlap very narrow, uniform; posterior shoulder high, rounded ; great- est height and thickness posterior. Length, 0.54 mm; height, 0.30 mm; width, 0.26 mm. Exline and Trivoli zones, localities 65, 66, 71. Healdia bicornis Cooper, n. sp. Plate 11, figures 26-28 Carapace of medium size, semiovate, dorsal margin broadly arched, ventral margin straight, ends rounded, with slight angulation of the margin antero- dorsally, posterodorsal margin slightly concave ; overlap moderate, variable ; long spines very close together, cone- shaped, flaring at base, and curved to- ward posterior; greatest height central; greatest thickness near center of poste- rior half, posterior shoulder inconspicu- ous, rounded. Length, 0.65 mm ; height, 0.38 mm ; width, 0.30 mm. //. bicornis differs from H. formosa Harlton and H. ampla Roundy in its higher, angulated anterior and the very closely-spaced spines, and in addition differs from the latter by the laterally directed spines and obtruse posterior outline as seen in dorsal view. Trivoli zone, locality 71. Healdia boggyensis Harlton Plate 11, figures 29-31 Healdia boggyensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 209, pi. 33, figs. 5a, b; Glenn group, Oklahoma. — Harl- ton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 265, pi. 2, figs. 7a, b; Boggy formation, Oklahoma. Carapace ovate, rather short, dorsal margin curved, ventral margin slightly convex; anterior end low, somewhat pointed; posterior end rounded; great- est height and thickness posterior ; over- lap variable, greatest around anterior margin, least along posterior and pos- terodorsal margins; posterior shoulder marked by a sharp line which bends for- ward toward the centrodorsal portion of hinge but which does not rise above sur- face of shell. Length, 0.54 mm; height, 0.32 mm; width, 0.28 mm. This species is distinguished from JET. marginata Harlton by its smaller form HEALDIIDAE 81 ratio and by the lack of a ridge on the posterior shoulder. Seville to Lowell zones, localities 4, 11, 14, 22. Healdia cara Bradfield Plate 11, figures 37, 38 Healdia cara Bradfield, 1935, Bull. Am. Pale- ontology, vol. 22, p. 110, pi. 9, figs. 16a, b; Deese? group, Oklahoma. Carapace semielliptical, dorsal margin gently arched, ventral margin quite con- vex, ends rounded, posterior end slightly more acuminate than anterior ; overlap moderate and uniform around entire margin; posterior shoulder inconspicu- ous, edge rounded; greatest height cen- tral, greatest thickness near middle of posterior half. Length, 0.54 mm; height, 0.34 mm; width 0.27 mm. Exline to Woodbury zones, localities 65, 66, 100, 109, 112, 115. Healdia carinata Cooper, n. sp. Plate 11, figures 35, 36 Carapace of medium size, semiellipti- cal, dorsal and ventral margins convex, ends broadly rounded ; moderate overlap uniform on all margins; spine very short, widely flaring at base, forming ventral end of very sharp-edged shoul- der which extends vertically upward above the line of articulation where it bends abruptly forward toward the hinge; greatest height and thickness posterior; surface smooth. Length, 0.59 mm ; height, 0.35 mm ; width, 0.27 mm. H. carinata may be distinguished from H. glennensis by its low arched dorsal outline and the straight, vertical position of the sharp ridge marking the posterior shoulder. LaSalle zone, locality 92. Healdia carterensis Bradfield Plate 11, figures 48, 49 Healdia carterensis Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. Ill, pi. 10, figs. 6a, b; Deese? group, Oklahoma. Carapace elongate, semielliptical, dor- sal and ventral margins convex; ends rounded ; overlap moderate, uniform ; spine long, cylindrical, flaring at base and joined by a very prominent, narrow ridge located very near the posterior terminus, giving the posterior end a squared appearance ; greatest height and thickness posterior. Length, 0.53 mm ; height, 0.30 mm ; width, 0.24 mm. Liverpool and St. David zones, locali- ties 23, 29, 30. Healdia cincta Coryell and Billings Plate 11, figures 32-34 Healdia cincta Coryell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 177, pi. 17, fig. 17; Wayland shale, Texas. Carapace small, semiovate, dorsal and ventral margins convex; ends rounded, anterior slightly higher than posterior; overlap slight, uniform on all margins; spines large, elongate, rising abruptly from shell surface, widely spaced so that they occur near dorsal and ventral mar- gins some distance in from posterior end; greatest height slightly anterior, greatest thickness posterior. Length, 0.50 mm ; height, 0.30 mm ; width, 0.27 mm. Gimlet and Trivoli zones, localities 58, 69. Healdia colonyi Coryell and Booth Plate 11, figures 43-47 Healdia colonyi Coryell and Booth, 1933, Am. Midland Naturalist, vol. 14, p. 266, pi. 4, figs. 9, 10; Wayland shale, Texas. Healdia deesensis Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 108, pi. 9, fig. 16; Deese? group, Oklahoma. Carapace large ; dorsal margin very highly arched, with equal slopes from central high point ; ventral margin straight in center, curving to meet rounded ends ; posterodorsal area flat- tened; overlap greatest along centrodor- sal and ventral margins ; spines promi- nent, directed backward, elongate, the upper one merging with well-developed ridge which is especially noticeable in 82 PENNSYLVANIA!? OSTRACODES the dorsal view; greatest height central, greatest thickness posterior. Length, 0.72 mm; height, 0.41 mm; width, 0.40 mm. Exline and Trivoli zones, localities 64, 69, 71. Healdia coryelli Kellett Plate 12, figures 14-16 Healdia compressa Kellett, 1935 (not Coryell and Billings, 1932), Jour. Paleontology, vol. 9, p. 142, pi. 16, figs. la-1; Howard formation, Kansas. Healdia coryelli Kellett, 1936, idem, vol. 10, p. 776. Carapace ovate, dorsal margin strong- ly arched, ventral margin convex; ends rounded and of equal height ; greatest height central, greatest thickness poste- rior, gradually tapering anterio rally forming a wedge-shaped, rather acumin- ate anterior outline in dorsal view; over- lap prominent in centrodorsal and ven- tral regions, moderate around ends; posterior shoulder rounded and of slight prominence. Length, 0.61 mm ; height, 0.41 mm ; width, 0.34 mm. Newton-Shumway zones, localities 109, 112. Healdia ehlersi Bradfield Plate 12, figures 6-8 Healdia ehlersi Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 109, pi. 9, figs. 11a, b; Deese? group, Oklahoma. Healdia angulata Bradfield. 1935, idem, p. 110, pi. 9, figs. 12a, b; Deese? group, Oklahoma. Carapace ovate, somewhat tumid, dor- sal margin strongly arched; ventral margin nearly straight ; ends rounded ; posterodorsal slope straight ; overlap variable, accentuated around anterior by development of narrow flat margin, showing in dorsal view, as narrow pro- trusions on both valves which often do not quite meet ; spines short, widely spaced, directed outward and backward, joined by a thick, knife-edged ridge. Length, 0.78 mm ; height, 0.45 mm ; width, 0.38 mm. The holotype of //. angulata is slight- ly smaller than that of H. ehlersi and is somewhat mashed and slightly distorted. However, the}' agree in all other respects and are identical to the Illinois speci- mens. Macoupin zone, locality 84. Healdia elegans Warthin Plate 12, figures 19-21 Healdia elegans Warthin, 1930, Oklahoma Geol. Survey, Bull. 53, p. 76, pi. 6, figs. 11a, b; Wetumka formation, Oklahoma. Healdia arcuata Coryell and Osario, 1932, Am. Midland Naturalist, vol. 13, p. 37, pi. 5, fig. 6, Nowata shale, Oklahoma. Healdia glennensis, Coryell and Sample, 1932, idem. p. 269, pi. 26, fig. 6; East Mountain shale, Texas. Healdia cf. H. glennensis, Bradfield, 1935, Bull. Am. Paleontology, vol. 23, p. Ill, pi. 19, figs. 17a, b only (not fig. 18); Hoxbar group, Oklahoma. Carapace large, dorsal margin strong- ly convex, ventral margin straight in center; overlap most prominent on cen- trodorsal margin ; posterodorsal area broad and flat, slope of left valve dis- tinctly concave ; spines long, prominent, directed outward and backward; great- est height central, greatest thickness posterior. Length, 0.85 mm; height, 0.54 mm; width, 0.37 mm. Seville to Jamestown zones, localities 7. 11, 13, 20, 41, 51. Healdia fabalis, Cooper, n. sp. Plate 12, figures 3-5 Carapace elongate, semielliptical ; dor- sal margin broadly convex, ends equally rounded ; overlap very narrow around all margins ; spines short, knoblike, the dorsal one poorly developed and consid- erably anterior to ventral spine ; poste- rior shoulder rounded and quite promi- nent ; greatest height central, greatest thickness near center of posterior half. Length, 0.59 mm; height, 0.33 mm; width, 0.29 mm. This species is somewhat similar to H. oblonga Bradfield but lacks the concavi- HEALDIIDAE 83 ty of the posterodorsal slope and the pronounced overlap of the latter. Seville zone, localities 3, 7. Healdia Formosa Harlton Plate 12, figures 9, 10 Healdia formosa Harlton, 1928, Jour. Paleon- tology, vol. 2, p. 135, pi. 21, figs. 7a, b; Gaptank formation, Texas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 108, pi. 9, fig. 10; Deese? group, Okla- homa, not — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 77, pi. 6, figs. 13a, b. Healdia bovicornis Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 108, pi. 9, fig. 14, Deese? group, Oklahoma. Carapace semielliptical, elongate, dor- sal margin arched, ventral margin al- most straight ; ends rounded ; prominent overlap uniform around all margins; posterior spines large, elongate, often curved inward toward each other ; prom- inent posterior shoulder lacking; great- est height anterior, greatest thickness posterior. Length, 0.77 mm; height, 0.44 mm; width, 0.32 mm. An examination of the holotypes shows that H. bovicornis is a broken and distorted specimen of H. formosa from the same locality and horizon. Exline zone, locality 64. Healdia glennensis Harlton Plate 12, figures 1, 2 Healdia glennensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 209, pi. 33, figs. 6a, b; Upper Glenn formation, Okla- homa. ■ — Harlton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 263, pi. 2, fig. 4; Upper Glenn formation, Oklahoma. Not Healdia glennensis, Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 269, pi. 26, fig. 6. —Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. Ill, pi. 7, figs. 17, 18. Carapace ovate; dorsal margin mod- erately arched, anterior and posterior slopes equal ; ventral margins straight ; ends equally rounded ; overlap moderate, greater along centrodorsal and ventral margins, least around ends ; usually only one spine, the lower one, developed, posterior shoulder rather prominent; greatest height central, greatest thick- ness posterior. Length, 0.57 mm ; height, 0.37 mm ; width 0.28 mm. Seville to Brereton zones, localities 3, 9, 26, 47. Healdia granosa Cooper, n. sp. Plate 12, figures 27-31 Carapace fairly large, semiovate, dor- sal margin strongly arched, ventral mar- gin slightly convex, ends rounded ; poste- rodorsal slope straight to slightly con- cave; spines short, flaring at base, and directed backward about 45° ; overlap moderate and uniform around all mar- gins; surface covered by elongate punc- tae arranged concentrically around cen- ter of the shell ; greatest height anterior, greatest thickness posterior; posterior shoulder broadly rounded, with no ridge between spines. Length, 0.77 mm; height, 0.48 mm; width, 0.36 mm. H. granosa resembles H. ehlersi Brad- field and H. elegans Warthin, but lacks the ridge between spines and the some- what acuminate anterior end of the former and the distinct concavity of the posterodorsal slope of the latter. Seahorne to St. David zones, localities 11, 16, 21, 22, 24, 28, 29, 30. Healdia limacoidea Knight Plate 12, figures 17, 18 Healdia limacoidea Knight, 1928, Jour. Pale- ontology, vol. 2, p. 333, pi. 44, figs. 5a-c; Labette formation, Missouri. — Wilson, 1933, Jour. Paleontology, vol. 7, p. 421, pi. 50, figs, la-d; McAlester shale, Okla- homa. Healdia longa Knight, 1928, idem, p. 332, pi. 44, figs. 6a-c; Labette formation, Mis- souri. — Warthin, 1930, idem, p. 75, pi. 6, figs. 10a, b; Wewoka and Holdenville formations, Oklahoma. Carapace ovate, dorsal margin arched, ventral margin straight, ends rounded; overlap moderate, fairly uniform ; spines of small diameter, short, and widely separated. 84 PENNSYLVANIAN OSTRACODES Length, 0.64 mm; height, 0.39 mm; width, 0.28 mm. Summum and Gimlet zones, localities 26, 59. Healdia longula Cooper, n. sp. Plate 12, figures 22-24 Healdia formosa, Warthin, 1930 (not Harl- ton), Oklahoma Geol. Survey Bull. 53, p. 77, pi. 6, figs. 13a, b; Wewoka forma- tion, Oklahoma. — Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 270, pi. 26, fig. 7, East Mountain shale, Texas. Healdia Tonga, Coryell and Sample, 1932 (not Knight), idem, vol. 13, p. 270, pi. 26, fig. 5; East Mountain shale, Texas. Carapace elongate, semielliptical, dor- sal margin broadly arched, ventral mar- gin straight to slightly convex, ends rounded; spines short, widely flaring at base, fairly widely spaced, and located very near posterior margin ; overlap moderate, fairly uniform; greatest height slightly anterior, greatest thick- ness near center of posterior half. Length, 0.61 mm ; height, 0.33 ; width, 0.28 mm. The species described by Warthin (1930) and Coryell and Sample (1932) have been placed in synonomy with H. limacoidea Knight (Kellett, 1936), but the difference in form ratios of 1.85 com- pared to 1.60 seems to indicate a differ- ent species. Seville zone, locality 3. Healdia marginata Harlton Plate 12, figures 39-41 Healdia marginata Harlton, 1928, Jour. Pale- ontology, vol. 2, p. 136, pi. 21, figs. 8a, b; "Caney" shale, Oklahoma. — Harlton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 262, pi. 1, figs. 11a, b; Springer and Johns Valley shales, Oklahoma. Healdia denisoni Harlton, 1929, idem, p. 262, pi. 1, fig. 12; Springer formation. Carapace ovate, dorsal margin arch- ed ; ventral margin slightly convex ; ends about equally rounded; posterodorsal slope straight ; greatest height central to slightly posterior; posterior end marked by a vertical knife-edged ridge rising abruptly from posterior shoulder, some- times with short knob-like spine at each end; greatest thickness posterior; over- lap moderate and uniform around all margins except posterdorsal. Length, 0.50 mm ; height, 0.30 mm ; width, 0.22 mm; form ratio, 1.68 to 1.75. II. marginata varies considerably in the length-height proportions of the lateral view, the more slender forms be- ing characterized by a longer postero- dorsal slope. However, the species may be recognized by the prominent ridge on the posterior shoulder. Seahorne and Liverpool zones, locali- ties 9, 13, 16. Healdia masoni Coryell and Booth Plate 12, figures 25, 26 Healdia masotii Coryell and Booth, 1933, Am. Midland Naturalist, vol. 14, p. 267, pi. 4, figs. 7, 8; Wayland shale, Texas. Carapace small, semielliptical, dorsal and ventral margins convex, ends round- ed ; posterior shoulder abrupt, nearly vertical, and very close to posterior ex- tremity ; overlap uniform, and moder- ate; greatest height central, greatest thickness posterior. Length, 0.37 mm; height, 0.22 mm; width, 0.17 mm. Little Vermilion zone, locality 105. Healdia nucleolata Knight Plate 12, figures 42-45 Healdia nucleolata Knight, 1928, Jour. Pale- ontology, vol. 2, p. 329, pi. 44, figs. 4a-c; Labette formation, Missouri. ? — War- thin, 1930, Oklahoma Geol. Survey Bull. 53, p. 75, pi. 6, figs. 9a, b; Wewoka formation, not — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 114, pi. 10, figs. 5a, b. Carapace ovate, of medium length; dorsal margin strongly arched, ventral margin convex; overlap moderate and uniform around all margins except me- soventral, where it is quite pronounced; posterior shoulder marked by narrow sharp ridge which curves forward to- ward the hinge; this ridge may carry short knob-like spines at upper and HEALDIIDAE 85 lower extremities, often with only the lower one; in well-preserved specimens the margin of each valve flares out at anterodorsal angle into a spine-like pro- tuberance. Length, 0.67 mm; height, 0.44 mm; width, 0.36 mm. Ferdinand to Summum zones, locali- ties 2, 14, 22, 26. Healdia oblonga Bradfield Plate 12, figures 46-48 Healdia oblonga Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 106, pi. 9, figs. 4a, b; Deese group, Oklahoma. Carapace elongate, dorsal and ventral margins broadly convex, ends rounded; pronounced overlap uniform except along posterodorsal slope; spines very short, flaring, and located well back from posterior end; posterior shoulder prominent, rounded, with no ridge be- tween spines; greatest height central, greatest thickness posterior. Length, 0.77 mm; height, 0.40 mm; width, 0.36 mm. The form ratio of this species (1.94) makes it one of the most elongate in the genus. Seahorne to Gimlet zones, localities, 11, 14, 16, 22, 26, 46, 47, 54, 55, 58. Healdia cf. H. obsolens Delo Plate 12, figures 32, 33 Healdia obsolens Delo, 1930, Jour. Paleon- tology, vol. 4, p. 168, pi. 13, figs. 4a-c; Pennsylvanian, western Texas. Carapace very short, ovate, dorsal and ventral margins strongly convex; ends rounded; overlap very prominent, and uniform around all margins except an- terior; posterior shoulder inconspicu- ous; greatest height central, greatest thickness posterior ; spines absent. Length, 0.41 mm; height, 0.30 mm; width, 0.24 mm. Although smaller than Delo's speci- mens, those from Illinois agree in all other features. This species is easily recognized by its low form ratio (1.41) which is smaller than for any other known species of Healdia. LaSalle zone, locality 88. Healdia oklahomaensis Harlton Plate 12, figures 34, 35 Healdia oklahomaensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 208, pi. 33, figs. 3a-c; Hoxbar group, Oklahoma. ? — Harl- ton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 263, pi. 2, fig. 5. ?— Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 268, pi. 26, fig. 4; East Moun- tain shale, Texas. Carapace ovate, dorsal margin s}^m- metrically arched, ventral margin slight- ly convex, ends rounded ; overlap moder- ate ; posterior shoulder abrupt, and bor- dered by a sharp line whose upper end bends forward toward hinge; greatest height central ; greatest thickness poste- rior. Length, 0.48 mm; height, 0.31 mm; width, 0.23 mm. The forms described by Harlton (1929) and Coryell and Osorio (1932) appear to differ in many respects from Harlton 's holotype, especially in the character of the lateral outline. Brereton to Little Vermilion zones, localities 39, 46, 48, 51, 54, 69, 70, 81, 93, 103. Healdia rectis Cooper, n. sp. Plate 12, figures 36-38 Carapace subrectangular, dorsal mar- gin broadly convex, ventral margin straight; ends asymmetrically rounded, anterior end narrower; overlap moder- ately wide, uniform; shoulder very ab- rupt, marked by sharp, narrow slightly curving vertical carina bearing a very faint spine at each end ; greatest height central, greatest thickness at posterior end, tapering with almost straight sides to anterior end, producing distinct wedgeshaped outline in dorsal view. Length, 0.51 mm; height, 0.30 mm; width, 0.23 mm. This species is similar to H. cuneata Coryell and Sample which, however, lacks the high posterior and distinctly 86 PENNSYLVANIAN ST R AC ODES wedge-shaped dorsal outline. Summum to St. David zones, localities 27, 30. Healdia simplex Roundy Plate 13, figures 1, 2 Healdia simplex Roundy, 1926, U. S. Geol. Survey Prof. Paper 146, p. 8, pi. 1, figs, lla-c; Graham group, Texas. — Kellett, 1935, Jour. Paleontology, vol. 9, p. 142, pi. 16, figs, 2a-c; Stanton formation. Kansas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 113, pi. 10, figs. 10a, b; Hoxbar group, Oklahoma. ?— Johnson, 1936, Nebraska Geol. Sur- vey Paper 11, p. 45, pi. 4, figs. 9-11; Stanton and Plattsburg foimations, Ne- braska. Not Healdia simplex. Coryell and Sample. Am. Midland Naturalist, vol. 13, p. 268, pi. 26, fig. 1. —Coryell and Sohn, 1938, Jour. Paleontology, vol. 12, p. 603, pi. 62, fig. 12. Healdia nucleolata, Bradfield, 1935 (not Knight), Bull. Am. Paleontology, vol. 22, p. 114, pi. 10, figs. 5a-6; Hoxbar group, Oklahoma. Healdia ciscoensis Bradfield, 1935 (not Harl- ton), idem, vol. 22, p. 113, pi. 9, figs. 20a, b; Hoxbar group, Oklahoma. Healdia malotti Payne, 1937 Jour. Palenotol- ogy, vol. 11, p. 286, pi. 40, figs. 3a, b; Hayden Branch formation, Indiana. Carapace semiovate, dorsal margin arched, ventral margin convex, posterior end rounded; anterior end angular, straight portion inclined slightly for- ward ; overlap moderate and fairly uni- form, slightly less around ends; poste- rior shoulder prominent with rounded edge ; greatest height nearly central, greatest thickness near center of poste- rior half ; surface smooth. Length, 0.74 mm; height, 0.46 mm; width, 0.35 mm. Macoupin to Shumway zones, locali- ties 84, 92, 93, 109. Healdia spinosa Cooper, n. sp. Plate 12, figures 11-13 Carapace small, semiovate, dorsal mar- gin arched, ventral margin slightly con- vex, ends rounded ; overlap very narrow, uniform ; spines elongate, cylindrical, rising abruptly from shell surface and directed laterally to high degree; poste- rior shoulder broadly rounded, lacking abruptness of most species; greatest height anterior; greatest thickness poste- rior, sides of posterolateral outline near- ly parallel. Length, 0.53 mm ; height, 0.33 mm ; width, 0.27 mm. Wile}^ to Gimlet zones, localities 13, 16, 26, 58. Healdia usitata Cooper, n. sp. Plate 13, figures 8, 9 Carapace semielliptical, dorsal margin arched, ventral margin convex; end rounded; overlap moderate, somewhat variable ; spines very short, widely flar- ing at base, and fairly widely spaced; posterior shoulder fairly prominent, rounded, posterodorsal slope broad and flat, with articulation somewhat incised; greatest height anterior, greatest thick- ness posterior. Length, 0.72 mm ; height, 0.45 mm ; width, 0.38 mm. Gimlet zone, locality 58. Genus Healdiacypris Bradfield, 1935 Heildiacypris acuminatus Cooper, n. sp. Plate 13, figures 10-13 Carapace sublenticular, dorsal margin strongly convex, ventral margin almost straight; ends pointed or acuminate in both lateral and dorsal views; anterior termination very low, well below mid- height, posterior termination at mid- height; overlap right over left, wide on all margins except along hingeline ; pos- terodorsal and anteroventral slopes long, less curved than opposite slopes; hinge very short, with reversal of overlap; greatest height and thickness posterior. Length, 0.69 mm; height, 0.41 mm; width, 0.30 mm. Although more acuminate and with a reversal of overlap as compared with the genotype species, H. acuminatus is, with- HOLLINIDAE out doubt, a Healdiacypris since it agrees in all other respects. The left over right overlap of H. perplexa Brad- field is not considered to be a generic character, which is true of a number of ostracode genera, notably Sansabella. Liverpool zone, locality 15. Healdiacypris perplexa Bradfield Plate 13, figures 17-20 Healdiacypris perplexa Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 103, pi. 8, figs. 13a, b; Deese group, Oklahoma. Carapace ovate to reniform, dorsal and ventral margins convex; ends nar- rowly rounded; overlap left over right, wide, and uniform on all margins except along hingeline ; hinge short, extending from just forward of midpoint of dor- sum to about two-thirds of distance to posterior end, its length almost exactly half total length of carapace ; greatest height anterior, greatest thickness poste- rior. Length, 0.78 mm; height, 0.44 mm; width 0.37 mm. Summum zone, locality 28. Genus Seminolites Coryell, 1928 Seminolites elongatus Coryell Plate 13, figures 14-16 Seminolites elongatus Coryell, 1928, Jour. Paleontology, vol. 2, p. 89, pi. 11, fig. 2; Holdenville formation, Oklahoma. — Coryell and Billings, 1932, Am. Mid- land Naturalist, vol. 13, p. 181, pi. 18, fig. 2, Wayland shale, Texas. Seminolites truncatus Coryell, 1928, idem, p. 89, pi. 11, fig. 4, Francis formation, Okla- homa. Carapace small, elongate; lateral out- line subelliptical ; dorsal margin arched ; ventral margin straight; ends sub- equally rounded ; overlap moderate, and uniform around all margins, except posterior; ridge bordering posterior margin prominent,with slightly depress- ed furrow on inside edge; surface smooth except for numerous scattered round shallow pits. Length, 0.83 mm ; height, 0.33 mm ; width, 0.27 mm. Shumway zone, localhy 109. Seminolites truncatus Coryell Plate 13, figures 3-7 Seminolites truncatus Coryell, 1928, Jour. Paleontology, vol. 2, p. 88, pi. 11, fig. 1; Wewoka formation, Oklahoma. — Cor- yell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 180, pi. 18, fig. 3; Wayland shale, Texas. Seminolites aff. S. truncatus, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 116, pi. 10, fig. 9; Deese group, Oklahoma. Seminolites compressus Coryell, 1928, Jour. Paleontology, vol. 2, p. 89, pi. 11, fig. 3; Francis formation, Oklahoma. — Coryell and Billings, 1932, Am. Midland Natural- ist, vol. 13, p. 180, pi. 18, fig. 1; Wayland shale, Texas. Seminolites aff. S. comjjressus, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 116, pi. 10, figs. 7a, b; Deese group, Oklahoma. Carapace small, short, rather tumid ; lateral outline subovate ; dorsal margin highly arched; ventral margin straight in center, turning upward anteriorly in wide curve to end margin, posterior curve sharper ; anterior end much higher than posterior; overlap wide except around posterior end; posterior ridge moderate to low, indistinct; shallow cir- cular pits sparse to fairly numerous. Length, 0.64 mm; height, 0.49 mm; width, 0.34 mm. Bogota and Shumway zones, localities 101, 109. Family Hollinidae Swartz, 1936 Genus Hollinella Coiyell, 1928 Hollina (part) Ulrich and Bassler, 1908, U. S. Nat. Mus. Proc, vol. 35, p. 315, pi. 42, figs. 5-20. —Knight, 1928, Jour. Paleon- tology, vol. 2, p. 235. —Latham, 1932, Royal Soc. Edinburgh Trans., vol. 57, pt. 2, p. 360. Hollinella Coryell, 1928, Jour. Paleontology, vol. 2, p. 377, pi. 51, figs. 1-3. — Kellett, 1929, idem, vol. 3, p. 196. —Blake, 1930, idem, vol. 4, p. 297. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 56. — Knight, 1930, Jour. Paleontology, vol. 88 PENN8YLVANIAN 0STRAC0DE8 4, p. 417. — Kellett, 1933, idem, vol. 7, p. 69. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 30. —Johnson, 1936, idem, Paper 11, p. 12. — Swartz, 1936, Jour. Paleontology, vol. 10, p. 551. Basslerina Moore, 1929, Denison Univ. Bull. Jour. Sci. Lab., vol. 24, p. 103. Hollites Coryell and Sample, 1932, Am. Mid- land Naturalist, vol. 13, p. 252. The genotype of Hollinella, H. den- tata Coryell, is an unf rilled form, as shown by Kellett 's (1929) analysis of the genus in which the three different specific forms were first recognized — the unfrilled, narrow-frilled, and wide-frill- ed specimens. Kellett (1936, p. 779) also inferentially recognized a fourth form with granulose shell surface, a variant of species having a papillose sur- face ornamentation. The original de- scription contains no discussion of gen- eric relationships and the close affinity of Hollinella to Hollina, which was erected by Ulrich and Bassler (1908) to include certain frilled nodose forms from the Sellersberg limestone (Devo- nian) at the Falls of the Ohio, was not mentioned. This is further shown by the fact that, while accepting Kellett 's thesis of the tripartite character of Hol- linella, Coryell and Sample (1932) de- scribed still another genus, Hollites, also an unfrilled form. Apparently Latham (1932) was not aware of the papers by Coryell and Kellett when she described Hollina avonensis. A number of ideas have been advanc- ed to explain the three divergent forms of Hollinella species. In Kellett 's (1929, pp. 197-198) opinion the unfrilled forms are immature males and females and the frilled forms are unproductive (narrow frill) and productive (wide frill) fe- males. However, Blake (1930) takes emphatic exception to this explanation, pointing out that periodomorphosis is not known in any of the Entomostraca, and that the frills may have served as " outriggers to prevent the animal from sinking too deeply into the soft mud, on the surface of which many forms live" or that "the frill subserved no function whatever. ' ' He also pointed out the difficulties involved in Ulrich and Bassler 's (1923, p. 275) idea that when the shell was closed the frill formed a pouch "for the temporary lodgement and protection of broods of young. ' ' The study of living species does not reveal that any crustacean cares for its young after they leave the mother. However, a living fresh-water species of Illinois, Darwinula stevensoni, retains the eggs during development, but in the postero- dorsal part of the shell cavity, whereas all other species are oviparous (Hoff, 1942, p. 37). Blake also pointed out the fact that the filling of the space between frills with a brood of young would seri- ously interfere with feeding and locomo- tion. A more reasonable explanation of the various specific forms of Hollinella can be gained by applying the methods of moult studies recently applied to a spe- cies of Ectodemites (Cooper, 1943, p. 49) in which nine instars (forms as- sumed in successive moult stages) were recognized from the probable nauplius to the mature adult. In plotting the length and height of all available frilled and unfrilled specimens of H. limata (Moore) from a sample of the Exline zone of Illinois six instars were recog- nized (see p. 93). Younger specimens may have been present in the sample but were not recovered. However, the five smaller instars are unfrilled, while all of the frilled forms are larger than the largest unfrilled instar. Of the frilled forms those with narrow frills have slightly larger body cavities 18 than those with wide convex frills. In other genera in which the male and female forms of a species can be recog- nized, the female is the larger. There- fore, by inference, the narrow-frilled Hollinella is the female, which is contra- 18 In measuring all forms of Hollinella, the single valve is mounted with the inside of the shell exposed, and the dimensions between the lines of articulation are measured. This eliminates a slight variation due to minor differences in shell thickness and the considerable variation which would result by the comparison of meas- urements of wide- and narrow-frilled forms, as well as variation in the convexity of wide-frilled forms. HOLLINIDAE 89 dictory to previously expressed opinions. Other inplications revealed by this analysis are that the unf rilled forms are all immature instars, as in modern forms the adult is represented by only one in- star, there being no further moults (Miiller, 1927, p. 422) ; and that only the frilled forms are adults, these being sexually differentiated. No unfrilled form has been ob- served to be as large as either male or female frilled adult of the same species. A similar analysis of specimens of H. radlerae and H. kellettae from the Penn- sylvanian of Illinois showed identical results. The lack of understanding of the ontogeny of the species assigned to this genus has resulted in a taxonomic snarl of no mean proportions. The failure to recognize uniform criteria as a basis of specific discriminations has also added to the confusion. While it is admittedly difficult, a sound method of separating immature and adult specimens and the recognition of sex differences in the frilled forms should clarify the situa- tion. Obviously no species should be founded on immature or unfrilled speci- mens. Since the genotype is not an adult form, a description of adult speci- mens from the same formation near the type locality (Wewoka formation, sec- tion 4, T. 3N, E. 7 E., Oklahoma) is presented under the systematic descrip- tions (p. 90). Specific variations include size of the adult, character of the lateral outline, minor surface markings (smooth, granu- lar, papillose), and size and relative position of the two nodes. Variations in the frill are not regarded as of specific importance. HOLLINELLA BURLINGAMENSIS Kellett Plate 13, figure 39 Hollinella ourlingamensis Kellett, 1933, Jour. Paleontology, vol. 7, p. 72, pi. 14, figs. 28-30; Burlingame limestone, Kansas. Hollinella menardensis, Kellett, 1929 (not Harlton), idem, vol. 3, p. 215, pi. 26, figs. 9a, b; p. 216, pi. 26, figs, la, b; Graham formation, Kansas. Hollinella verrucula Moore, 1929, Denison Univ. Bull. Jour. Sci. Lab., vol. 24, p. 107, pi. 6, fig. 6; pi. 7, figs. 5, 6; pi. 8, figs. 3, 4; South Bend shale, Texas. Carapace elongate ; hinge long, straight; frill fairly wide, flaring, and incurved, especially in posterior por- tion ; anterior nodes large, prominent, each rising so abruptly from the shell surface that the base of the node seems smaller than its diameter ; sulcus deep and bordered ventrally by longitudinal swelling of shell surface (not a node) ; surface granulose. Length, 1.10 mm; height, 0.59 mm. Shumway to Woodbury zones, locali- ties 110, 113, 115. Hollinella crassimarginata Kellett Plate 13, figures 25-27 Hollinella crassimarginata Kellett, 1929, Jour. Paleontology, vol. 3, p. 206, pi. 26, figs. 3a, b, 7; Stanton to Ft. Riley forma- tions, Kansas. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 31, pi. 4, fig. 5a; Permian, Nebraska. Carapace elongate ; hinge shorter than shell length ; anterior node low, well-de- veloped, and of large diameter ; posterior node but little higher than shell surface ; sulcus deep, flaring at ventral end below nodes; frill narrow, thickened on outer edge becoming wide, flaring, and slightly incurved anteriorly ; surface smooth to granulose. Length, 1.13 mm; height, 0.66 mm; width, 0.54 mm. This species is a good example of the variably frilled forms of Hollinella, as it includes wide, narrow, and unfrilled forms. Bogota to Woodbury zones, localities 103, 107, 115. no PEXXS YLVAXIA X OSTIL 1 COOKS HOLLINELLA CUSHMANI Kellett Plate 13, figure 40 Hollinella cushmani Kellett, 1933, Jour. Paleontology, vol. 7, p. 71, pi. 13, figs. 35-37; Deer Creek formation, Kansas. Hollinella emaciata, Upson, (not Ulrich and Bassler), Nebraska Geol. Survey Bull. 8, p. 32, pi. 4, figs. 2a-c; Garrison shale, Nebraska. Carapace comparatively short, high; hinge short; frill wide, flaring, and strongly vmcurved posteriorly, nodes prominent, defining deep snlcns which curves ventrally below small node ; sur- face granulose. Length, 1.26 mm ; height, 0.70 mm. Shoal Creek to Woodbury zones, local- ities 78, 81, 90, 115. Hollinella dentata Coryell Plate 13, figures 32-38 Hollinella dentata Coryell, 1928, Jour. Pale- ontology, vol. 2, p. 379, pi. 51. fig 1; Wewoka formation. Oklahoma. Basslerina linibata Moore, 1929, Denison Univ. Bull. Jour. Sci. Lab., vol. 24, p. 110, pi. 6, fig. 7; pi. 7, figs. 11, 12; pi. 8, figs. 13, 14; Wewoka formation, Okla- homa. Not Hollinella limbata, Warthin, 1930. Okla- homa Geol. Survey Bull. 53, p. 58, pi. 4, fig. 4. Hollinella hassleri, Warthin, 1930 (not Knight), idem, p. 57, pi. 4, figs. 3a, b; Wewoka formation, Oklahoma. Hollinella bulbosa Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 251, pi. 24, fig. 7; East Mountain shale, Texas. Hollinella harltoni, Coryell and Sample, 1932, (not Kellett), idem, p. 251, pi. 24, fig. 8, Hollinella cf. H. pulchra, Bradfield, 1935 (not Moore), Bull. Am. Paleontology, vol. 22, p. 48, pi. 2, figs. 2, 3, Deese group, Oklahoma. Carapace large, somewbat flat, subrec- tangular, with little forward "swing"; binge line long, straight, with long ante- rior spine; anterior node very large, ris- ing abruptly from shell, upper edge co- incident with binge line; posterior node small, poorly developed, hardly more than slight swelling of shell surface; frill wide, flaring, very thin, so it often is irregularly broken; sulcus wide, shal- low; surface finely granulose, without spines. Length, 1.03 mm; height, 0.58 mm. A close examination of topotype speci- mens from Warthin 's localities in the Wewoka formation of Oklahoma and specimens from comparable horizons in Illinois shows that the largest unfrilled forms, when compared with the geno- type species, are indistinguishable and .6 .5 - D ADULT J TOPOTYPE MATERIAL, X IN STARS ) H. limbata Jf^ • H. dentata GENOHOLOTYPE x"A O H. ovata ^s^ A H. regular is ^y^ O i i i i I .7 .8 LENGTH (mm) 1.0 I. I 1.2 Fig. 34 — Graph of length-height dimensions of Hollinella dentata Coryell. HOLLINIDAE 91 therefore probably conspecific. The plotting of measurements of the geno- type species with a large number of spec- imens of H. limbata shows that the former is a next-to-last instar (M — 1) in the moult series. The broad very fragile frill and large conspicuous nodes make this a distinctive species. Fulda to Jamestown zones, localities 1, 4, 12, 16, 20, 22, 26, 30, 31, 36, 37, 50. HOLLINELLA ELONGATA Cooper, n. Sp. Plate 13, figures 28, 29 Carapace rather small, elongate, tu- mid ; hinge line long, straight ; frill quite narrow, flaring; anterior node large, prominent, slightly ovate in outline; posterior node small, low, inconspicuous ; surface finely granulose, without spines or papillae except along anterior mar- gin between end of frill and dorsal angle. Length, 0.95 mm ; height, 0.47 mm ; thickness, 0.50 mm. Brereton zone, locality 37. Hollinella emaciata (Ulrich and Bassler) Plate 13, figures 21-24 Beyrichiaf emaciata Ulrich and Bassler, 1906, U. S. Nat. Museum Proc, vol. 30, p. 157, pi. 1, fig. 6; "Wreford limestone, Kansas. Hollina emaciata Ulrich and Bassler, 1908, U. S. Nat. Museum Proc, vol. 35, p. 315. Hollinella emaciata, Kellett, 1929, Jour. Pale- ontology, vol. 3, p. 202, pi. 25, figs, la-c; Cottonwood and Ft. Riley formations, Kansas. Carapace subtrapezif orm ; hinge fair- ly short ; frill narrow, outer rim thick- ened; anterior node large, flat, upper edge even with hinge line ; posterior node small, low, and indistinct, especi- ally on posteroventral margin where it merges imperceptibly with the shell sur- face ; surface pitted, anterior surface and edge spinose. Length, 1.08 mm; height, 0.57 mm; width, 0.51 mm. Shumway zone, locality 112. Hollinella gibbosa Kellett Plate 13, figure 31 Hollinella gibbosa, Kellett, 1929, Jour. Pale- ontology, vol. 3, p. 208, pi. 25, figs. 3a-c; pi. 26, figs. 2a-c, 5, 11; Burlingame to Ft. Riley formations, Kansas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 47, pi. 2, fig. 1; Deese group, Oklahoma. Hollina granifera, Harlton, 1927 (not Ul- rich), Jour. Paleontology, vol. 1, p. 204, pi. 32, fig. 3, Hoxbar group, Oklahoma. Carapace somewhat elongate, hinge straight, of moderate length ; nodes rais- ed conspicuously above shell surface, larger one often rising above hinge line ; sulcus deep, expanding ventrally so that a narrow ridge seems to join the nodes (shown in accenuated manner by Harl- ton 's figure) ; frill wide, flaring, and in- curved posteriorly ; surface smooth to finely granulose; anterior margin faint- ly spinose. Length, 1.13 mm; height, 0.63 mm. Shumway zone, localities 109, 112. Hollinella grahamensis (Harlton) Plate 13, figure 30 Hollina grahamensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 203, pi. 32, figs. 2a, b; Upper Glenn (Hoxbar group), Oklahoma. Hollinella grahamensis, Kellett, 1929, Jour. Paleontology, vol. 3, p. 215, pi. 26, fig. 11. —Harlton, 1929, Texas Univ. Bull. 2901, p. 145, pi. 1, fig. 7, Canyon series, Texas. Hollinella harltoni Kellett, 1929, Jour. Pale- ontology, vol. 3, p. 213, pi. 26, figs. lOa-c; Belle City limestone, Oklahoma. Carapace fairly short ; hinge long, al- most equal to length of shell, anterior node of large diameter, high, and often protruding above hinge line ; diameter of posterior node about two-thirds that of larger node, extending well above shell surface, even along posteroventral margin ; sulcus wide, shallow, flaring ventralty ; curvature of shell regular, and uninterrupted in ventral half except for row of short nodose spines in lieu of a flange subparallel to the ventral mar- gin. 92 PENNSYLVANIAN OSTRACODES Length, 0.90 mm ; height, 0.52 mm. As no described specimen of this spe- cies (and also H. harltoni) shows the frilled form, it is therefore identified with some uncertainty (see remarks un- der H. oklahomaensis, p. 94). Bogota zone, locality 100. HOLLINELLA GRANDIS Cooper, 11. Sp. Plate 13, figures 41-46 Carapace large, tumid; hinge line long, straight ; frill moderately wide, thin, flaring to slightly incurred near posterior end, with onty a rudimentary spine developed on some specimens; an- terior node very large, rises abruptly from shell surface and is wholly on an- terior portion of shell ; posterior node small, but prominent ; sinus fairly broad, deep, and centrally located; surface finely granulose. Length, 1.23 mm ; height, 0.64 mm ; width, 0.75 mm. H. grandis is probably the largest known Pennsylvanian Hollinella. It is further differentiated by the extreme an- terior position of the very prominent anterior node. Gimlet and Macoupin zones, localities 58, 86. Hollinella kellettae Knight Plate 14, figures 6-10 Hollina ulrichi Knight, 1928, Jour. Paleon- tology, vol. 2, p. 237, pi. 31, figs. 4a, b; Labette formation, Missouri. — Harlton, 1929, Texas Univ. Bull. 2901, p. 141, pi. 1, fig. 3, Canyon series, Texas. Hollinella fortscottensis Knight, 1928, Jour. Paleontology, vol. 2, p. 237, pi. 31, fig. 2, Labette formation, Missouri. Hollinella ulrichi, Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 56, pi. 4, figs. 6a, b, Holdenville formation, Oklahoma. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 13, pi. 1, figs. 1-4; Upper Missouri group, Nebraska. Hollinella kellettae Knight in Kellett, 1933, Jour. Paleontology, vol. 7, p. 70 . Not Hollinella kellettae. Coryell and Booth, 1933, Am. Midland Naturalist, vol 15, p. 271, pi. 5, figs. 8-10. Carapace large, with pronounced backward "swing"; hinge line long, straight, right valve has short spine on posterior end and a much longer slightly curved spine on anterior end ; anterior node of large diameter stands high above shell surface and carries the same mark- ings as rest of shell, namely granulations and numerous short rounded spines; posterior node about half as thick, merges with shell surface posteroven- trally; frill wide, flaring, incurved for half its length posteriorally, terminated near anterior end by large spine. Length (figs. 7, 8), 1.06 mm; height, 0.60 mm. When renaming Beyrichiaf radiata Jones and Kirkby to Hollinella digitata, Kellett (1929, p. 209), overlooked the fact that Knight (1928, p. 237) previ- ously had renamed this species H. ulrichi. Later Kellett postulated differ- ences between the forms collected from the Middle Pennsylvanian of Missouri and those from the Permian of Kansas. In the meantime other species called H. digitata and H. ulrichi were described from the Middle Pennsylvanian of Okla- homa (Warthin, 1930; Coryell and Sample, 1932; Bradfield, 1935). Still later Johnson (1936, p. 133) pointed out that the criteria proposed for recogniz- ing differences between the Permian and Middle Pennsylvanian species did not hold because they could be applied equally well to specimens of Hollinella from either system. He placed all of the above, as well as other papillose forms, in synonomy with H. ulrichi, recogniz- ing wide-frilled, narrow-frilled, and un- frilled forms in the LTpper Kansas City and Lansing groups of the Pennsyl- vanian of Nebraska. However the papillose forms, ranging in age from middle Des Moines to Lower Permian, are now thought to represent three separate and distinct species, namely H. kellettae, H. oldahomaensis, and H. ulrichi. The separation is based on differences in size and form ratio, as follows : HOLLINIDAE 93 Species Length Height Form Ratio (adults) (mm) (mm) (L/H) $ 6 $ 5 5 5 H. kellettae. 1.005 1.005 0.552 0.555 1.83 1.86 H. oklahoma- ensis 1.08 1.11 0.57 0.58 1.88 1.90 H. ulrichi ..0.97 0.50 1.95 As in other species of Hollinella the unfrilled forms can be shown to be im- mature instars, which in themselves can- not be recognized specifically. Stratigraphically H. kellettae in Illi- nois ranges from the Liverpool to St. David zones (localities 14, 16, 17, 22, 31), and thus is restricted to the upper Des Moines series from the Ardmore to the Labette. II. oklahomaensis is known from the Sparland (No. 7 coal horizon) to the top of the Pennsylvanian section and is distinct from the smaller, shorter II. ulrichi (pi. 14, figs. 16, 17) which has not yet been found in the Pennsylvanian and appears to be restricted to the Permian. Hollinella levis Cooper, n. sp. Plate 14, figure 1 Carapace large, subquadrangular ; hinge line long, straight ; anterior node large, fairly low, rising gradually from shell surface; posterior node small, low, indistinct, and located high on the shell ; sulcus unusually broad, shallow, and widely flaring in lower part; frill thick, narrow, flaring, and terminated ante- riorly by broad short spine ; surface very smooth, except for occasional short papillose spines. Length, 1.13 mm; height, 0.62 mm. H. levis may be distinguished by its very smooth surface broken by very sparsely distributed papillae. Brereton and Gimlet zones, localities 44, 59, 62. Hollinella limata (Moore) Plate 14, figures 31-36 Basslerina limata Moore, 1929, Denison Univ. Bull. Jour. Sci. Lab., vol. 24, p. 106, pi. 6, fig. 1; pi. 7, fig. 3, pi. 8, figs. 5, 6; Graham group, Texas. Carapace elongate, tumid; hinge line long, straight; anterior node of large diameter and considerable height, poste- rior node about half as large ; sulcus very broad and shallow, flaring at base so that edge of posterior node is well de- fined around most of its perimeter; flange of moderate width, flaring out- ward for its entire length, and termin- ated anteriorly by a large forward-curv- ing spine; surface granulose. .6 .5 - .3 - FRILL WIDE , FLARING O FRILL NARROW, INCURVED X NO FRILL .4 .6 1.0 II .7 .8 .9 LENGTH (mm.) Fig. 35 — Graph of length-height dimensions of Hollinella limata (Moore) 1.2 94 PENNSYLVANIAN OSTRACODES Length, 1.26 mm; height, 0.64 mm; width, 0.66 mm. Piasa to Millersville zones, localities 54, 66, 90. HOLLINELLA MINUTA Cooper 11. Sp. Plate 14, figures 11, 12 Carapace small, somewhat inflated; form ratio average; hinge line straight; anterior node very large, high on cara- pace, upper edge slightly overlapping the hinge line ; frill very wide, flaring to convex in posterior portion, anterior end marked by a short thick spine; surface extremely coarsely granulose, with a few short spines scattered sparsely over the surface of the shell and nodes. Length, 0.79 ; height, 0.46 mm. H. minuta is the smallest adult species known, and may be further differen- tiated by its very coarsely papillose sur- face and relatively wide frill. Seahorne to Lowell zones, localities 11, 14, 16, 22. HOLLINELLA MOOREI Cooper, 11. Sp. Plate 14, figures 13, 14 Basslerina regularis Moore, 1929, Denison Univ. Jour. Sci. Lab. vol. 24, p. 108, pi. 6, fig. 3; pi. 8, figs. 7, 8, 15; Graham group, Texas. Hollinella ~bassleri Coryell and Billings, 1932 (not Knight), Am. Midland Naturalist, vol. 13, p. 185, pi. 18, fig. 4; Wayland shale, Texas. Carapace large, slightly flat, somewhat elongate, with little forward "swing"; hinge almost as long as shell; anterior node large, hemispherical, standing slightly above hinge line ; posterior node one-fifth to one-fourth as large, low, and inconspicuous ; surface coarsely punctate, devoid of spinelets except near anterior margin and an occasional one near hing-e line; flange relatively nar- row, flaring, terminated by large blunt spine. Since Basslerina is a synonym of Hol- linella, B. regularis Moore on being transferred becomes a junior homonym to H. regularis Coryell, 1928. Length, 1.10 mm; height, 0.60 mm. Shumway zone, locality 112. Hollinella nowataensis Coryell and Osorio Plate 14, figure 19 Hollinella nowataensis Coryell and Osorio, 1932, Am. Midland Naturalist, vol. 13, p. 29, pi. 5, fig. 1; Nowata shale, Okla- homa. Hollinella in flat a Coryell and Osorio, 1932, idem, p. 29, pi. 5, fig. 2; Nowata shale, Oklahoma. Carapace short, hinge line straight and relatively short ; anterior node very large, rising abruptly from shell surface, slightly spinose ; posterior node less than one-half as wide, rising only slightly above shell surface, except where it borders sulcus; sulcus narrow and deep, widening ventrally ; nodes seem to be joined ventrally by a wide curved ridge, formed by inflated shell surface between the nodes and the flange; flange moder- ately wide, with terminal spine flaring anteriorly, incurved posteriorly where it merges imperceptibly with shell sur- face ; shell surface very finely granulose except anteriorly where it is somewhat spinose. Length, 1.30 mm; height, 0.60 mm. Gimlet zone, localities 58, 62. Hollinella oklahomaensis (Harlton) Plate 14, figures 37-45 Jonesina oklahomaensis Harlton, 1929, Jour. Paleontology, vol. 2, p. 133, pi. 21, figs. 3a, b; Belle City limestone, Oklahoma. Hollinella oklahomaensis, Harlton, 1929, Texas Univ. Bull. 2901, p. 146, pi. 1, figs. 8a, b; Canyon series, Texas. — Kellett, 1929, Jour. Paleontology, vol. 3, p. 215, pi. 26, figs. 13a, b; Belle City limestone, Oklahoma. ■ — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 18, pi. 1, figs. 13, 14; Chanute shale, Nebraska. Hollites papillosus Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 252, pi. 24, fig. 9; East Mountain shale, Texas. Carapace elongate; hinge line fairly long ; anterior node large ; posterior HOLLINIDAE 95 node about one-fourth as wide, faint, in- conspicuous ; sulcus deep, moderately wide ; flange wide, anteriorly terminated by large spine; shell surface rather coarsely granulose, with numerous short spines. Length (figs. 37-39) 1.30 mm: height, 0.63 mm ; width, 0.63 mm. A number of unfrilled forms have been described from various parts of the Missouri series in Oklahoma and Texas. It is not possible to recognize some of these species with any degree of certain- ty until larger collections containing both young and adult instars are studied. The Exline zone of Illinois con- tains a large number of variously sized specimens of H. oklahomaensis among which five instars can be recognized, as well as the wide-frilled and narrow- frilled adults. H. papillosus is the third instar removed from the adult (M — 3). See remarks under H. kellettae (p. 92). Sparland to Shumway zones, localities 54, 55, 66, 67, 70, 76, 86, 87, 102, 112. HOLLINELLA PULCHRA (Moore) Plate 14, figure 15 Basslerina pulchra Moore, 1929, Denison Univ. Bull. Jour. Sci. Lab., vol. 24, p. 109, pi. 6, fig. 5; pi. 7, figs. 1, 2; pi. 8, figs. 1, 2; South Bend shale, Texas. Carapace small, subquadrate, hinge line slightly concave ; frill moderately wide, thin, and flaring; anterior node rather small, but prominent; posterior node relatively large, situated close to larger node ; surface finely granulose. Length, 0.88 mm; height, 0.46 mm. Brereton zone, locality 47. HOLLINELLA RADLERAE (HarltOll) Plate 14, figures 2-5 Hollina radlerae Harlton, 1928, Jour. Paleon- tology, vol. 2, p. 133, pi. 21, figs. 2a, b; Bell City limestone, Oklahoma. — Harl- ton, 1929, Texas Univ. Bull. 2901, p. 141, pi. 1, figs. 2a-c; Canyon series, Texas. Hollinella radlerae, Kellett, 1929, Jour. Pale- ontology, vol. 3, p. 199, pi. 26, fig. 6. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 17, pi. 1, figs. 10, 11; Cha- nute shale, Nebraska. Hollina tricollina, Harlton, 1927 (not Ul- rich), Jour. Paleontology, vol. 1, p. 204, pi. 32, figs. 4a, b; Lower Glenn (?Dor- nick Hills group), Oklahoma. Hollina oosita Moore, 1929, Denison Univ. Bull. Jour. Sci. Lab., vol. 24, p. 104, pi. 6, fig. 4; pi. 7, figs. 9, 10; pi. 8, figs. 11, 12; Francis formation, Oklahoma. Carapace large, very tumid; hinge line straight, almost as long as shell ; an- terior node very large, often overlapping hinge line ; usual posterior node very small, inconspicuous, but a somewhat .5 E E K.4 I o D FRILL WIDE, FLARING x ^^ ^^ o O FRILL NARROW, INCURVED X NO FRILL y^^ ^"^" X 1 i i i i i . -i .3 .7 .8 LENGTH (mm.) 1.0 1.2 Pig. 36 — Graph of length-height dimensions of Hollinella oklahomaensis Harlton. 96 PENN8YLVANIAN OSTRACOBES larger third node lies above and behind the usual position of the posterior node ; this third node stands above the hinge line on a level with the large anterior node; frill wide, heavy, smooth, poste- rior portion incurved, posterior end terminated by small spine ; sulcus quite wide and deep ; shell below sulcus is deeply depressed near the flange; sur- face of shell and nodes covered with ex- tremely coarse granulations, some of which appear to become small spines on anterior end. Length, 1.05 mm; height, 0.60 mm; width, 0.60 mm. LaSalle zone, locality 88. HOLLINELLA REGULARIS Coryell Plate 14, figures 20-26 Hollinella regularis Coryell, 1928, Jour. Paleontology, vol. 2, p. 380, pi. 51, fig. 3; Francis formation, Oklahoma. Hollinella ovata Coryell, 1928, idem, p. 380, pi. 51, fig. 2; Francis formation, Okla- homa. Not Basslerina regularis Moore, 1929, Deni- son Univ., Jour. Sci. Lab., vol. 24, p. 108, pi. 6, fig. 3; pi. 8, figs. 7, 8, 15; Graham group, Texas. Hollinella menardensis Harlton, 1929, Texas Univ. Bull. 2901, p. 145, pi. 1, figs. 6a, b; Canyon series, Texas. Hollinella fortscottensis, Harlton, 1929 (not Knight), idem, p. 145, pi. 1, fig. 5. Hollinella buehleri, Harlton, 1929 (not Knight), idem, p. 144, pi. 1, fig. 4. Carapace of medium size, somewhat tumid; hinge line long, straight; ante- rior node of very large diameter, quite high; posterior node about one-half as large, low, and close to anterior node, forming very narrow deep sulcus, which flares ventrally, particularly toward posterior, thus accentuating the smaller node ; shell below sulcus is depressed rapidly toward flange, giving somewhat the appearance of a ridge joining the two nodes; flange broad, prominently flaring anteriorly, slightly incurved posteriorly, a large curved spine marks anterior end of flange; surface granu- lose, with a few short spines. Length, 1.02 mm; height, 0.60 mm; width, 0.54 mm. A comparison of frilled forms from well known localities in the Francis formation, a short distance south of Cor- yell 's type locality, shows the occurrence of unfrilled with frilled forms. Accord- ing to the measurements of the holotye it is an instar two removed from the adult (M — 2). II. ovata from the same horizon and locality is thought to be a slightly mashed specimen of this species, since it differs only in thickness. The size and shape of most specimens of Hol- linella from this locality have been modi- fied to some extent by the pressure of the enclosing shale. Gimlet to Woodbury zones, localities 59, 62, 79, 81, 88, 100, 107, 115. Hollinella siiawnensis Kellett Plate 14, figure 18 Hollinella shawnensis Kellett, 1929, Jour. Paleontology, vol. 3, p. 209, pi. 25, figs. 4a-c; pi. 26, fig. 8; Deer Creek to How- ard formations, Kansas. Hollinella kellettae, Coryell and Booth, 1933 (not Knight), Am. Midland Naturalist, vol. 14, p. 271, pi. 5, figs 8-10; Wayland shale, Texas. Carapace large, rather short; hinge line relatively short; anterior node large, circular to slightly ovate in out- line, rising above hinge line ; posterior node about one-third as large, low, and inconspicuous, flange wide, radially "laminated," posterior portion incurv- ed, anterior half flaring and terminated by a long thick curved spine ; surface very coarsely granulose, with several short stubby spinelets scattered over sur- face of shell and large node. Length, 1.08 mm; height, 0.63 mm. Trivoli to Shumway zones, localities 70, 72, 109, 112. Hollinella warthini Cooper, n. sp. Plate 14, figures 27-30 Hollinella digitata, Warthin, 1929 (not Kel- lett), Oklahoma Geol. Survey Bull. 53, p. 57, pi. 4, fig. 5; Holdenville formation, KIRKBYIIDAE 97 Oklahoma. ?— Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 250, pi. 24, fig. 15; East Mountain shale, Texas. Hollinella ulrichi, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 48, pi. 2, fig. 4; Hoxbar group, Oklahoma. Carapace elongate, hinge line straight ; nodes unusually prominent, anterior node of very large diameter, rising ab- ruptly from shell surface, its upper edge extending above the hinge line; poste- rior node small but well defined ; frill of moderate width, flaring surface covered by small very uniform granulations. Length, 1.21 mm; height, 0.64 mm; width, 0.60 mm. Representatives of this sepcies have been erroneously identified as H. digi- tata and H. ulrichi (see p. 92). Brereton to Exline zones, localities 37, 49, 58, 66. Family Kirkbyiidae Ulrich and Bassler, 1923 Genus Amphissites Girty, 1910 Amphissites adjunctio Cooper, n. sp. Plate 15, figures 29-31 Carapace large, subquadrate, ends rounded, hinge long; medial and dorso- posterior nodes high, rising abruptly from surface of shell ; outer carina well developed, heavy, bordered by row of very large reticuli, inner carina simi- larly bordered, prominent, parallel to outer ridge, curving upward in the ven- tral angles where it becomes progres- sively lower and finally merges with the surface of the shell ; short but prominent curved carina beginning at anterior edge of pit beneath center of medial node extends horizontally for a short distance, then curves upward parallel to the inner carina, and merges with the shell surface at a point even with the center of the medial node ; pit large, ovate, below and slightly back of center of median node, axis inclined anteriorly; surface marked by medium to coarse reticulations. Length, 1.16 mm; height, 0.64 mm; width, 0.63 mm. This species may be easily recognized by the presence of the short, curved carina, ventroanterior to the medial node. Livingston zone, locality 93. Amphissites alticostatus Bradfield Plate 15, figures 9-11 Amphissites alticostatus Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 58, pi. 4, fig. 4, Dornick Hills group, Oklahoma. Carapace small, subquadrate; hinge depressed ; dorsal margin distinctly con- cave in young specimens (see Bradfield, 1935) less so in older forms; ventral margin straight to slightly convex; carinae very prominent, smooth, and present on medial, anterior, and poste- rior swellings ; inner carina promi- nent in midportion where it paral- lels outer carina, but on turning upward at ventral angles, soon merges with the surface of the shell ; carina on the slight median node inclined slightly to poste- rior; carinae on terminal swelling low, thin, but distinct, posterior one more prominent; surface covered by reticula- tions of medium size. Length, 0.77 mm; height, 0.45 mm; width, 0.42 mm. Fulda to Liverpool zones localities 1, 2, 16. Amphissites carinatus Cooper, n. sp. Plate 15, figures 15-18; 21, 22 Carapace elongate, ends rounded, hinge straight; medial node small but prominent, and characterized by a short transverse carina on posteroventral mar- gin bordering the pit ; carina high, thin, the inner one parallel to outer along venter, merging around ends and meet- ing at the dorsal angles; two fairly prominent thin ridges occupy a midpo- sition between node and inner carina, extending from the dorsal margin to a point slightly below the ventral ma ruin of the node. 98 PENNSYLVANIA 08TB AC ODE 8 Length, (figs. 17, 18) 0.77 mm; height, 0.45 mm ; width, 0.38 mm. This species is similar to A. centrono- tus (Ulrich and Bassler) in all respects except for the small ridge which partial- ly crosses the ventral node. Bogota and Woodbury zones, localities 101, 115. Amphissites centronotus (Ulrich and Bassler) Plate 15, figures 19-22 Kirkbya centronotus Ulrich and Bassler, 1906, U.S. Nat. Mus. Proc, vol. 30 p. 159, pi. 11, figs. 16, 17; Cottonwood shale, Kansas. Amphissites centronotus Roundy, 1926, U. S. Geol. Survey, Prof. Paper, 146, p. 7. — Harlton, 1927, Jour. Paleontology, vol. 1, p. 207, pi. 32, figs. 10a, b; Hoxbar group, Oklahoma. — Knight, 1928, idem, vol. 2, p. 259, pi. 32, figs. 6a-e; pi. 34, fig. 2; Labette formation, Missouri. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 66, pi. 5, figs. 4a-c; Wetumka, Wewoka, Holdenville formations, Okla- homa. — Delo, 1930, Jour. Paleontology, vol. 4. p. 160, pi. 12, fig. 9. —Coryell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 184, pi. 18, fig. 9; Wayland shale, Texas. — Coryell and Sample, 1932, idem, vol. 13 p. 258, pi. 25, fig. 1; East Mountain shale, Texas. — Kellett, 1933, Jour. Paleontology, vol. 7, p. 95, pi. 16, figs. 16-22; Middle Pennsylvanian to Wreford formation, Kansas^ — Coryell and Booth, 1933, Am. Midland Natural- ist, vol. 14, p. 260, pi. 3, figs. 1, 2; Way- land shale, Texas. — Upson, 1933, Nebras- ka Geol. Survey Bull. 8, p. 42, pi. 3, figs. 7a-c; Florena-Cottonwood formations, Kansas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 59, pi. 3, fig. 3; Deese formation, Oklahoma. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 30, pi. 3, figs. 12-14; Island Creek, Captain Creek, Stark, Quivira, Muncie Creek, Lane, Spring Hill, Endora, and South Bend formations, Nebraska. Albanella gouldi Harris and Lalicker, 1932, Am. Midland Naturalist, vol. 13, p. 397, pi. 36, figs. 2a, b; Wreford limestone, Kansas. Not Amphissites centronotus, Latham, 1933, Royal Soc. Edinburgh Trans., vol. 57, pt. 2, no. 12, p. 370, fig. 17; Carboniferous, Scotland. Not Amphissites cf. A. centronotus, Kum- merow, 1939,Preuss, geol. Landesanstalt, Abh., n.f., no. 194, pt. A, p. 29, pi. 3, fig. 4; Tournaisian-Visean, Germany. Not Amphissites centronotus?, Croneis and Gale, 1938, Denison Univ. Bull. Jour. Sci. Lab., vol. 33, p. 270, pi. 5, fig. 9; Gol- conda formation, Illinois. Not Amphissites centronotus elongatus Payne, 1937, Jour Paleontology, vol. 11, p. 280, pi. 38, figs. 2a-c; Hayden Branch formation, Indiana. Length (figs. 21, 22), 0.80 mm; height, 0.45 ; width, 0.44 mm. This well known species needs no further description. Its occurrence throughout most of the Pennsylvanian and well into the Permian makes its range one of the longest authenticated to date. In Illinois it is known from the Seville to the Woodbury, or from almost all of the known ostracode-bearing strata of the Pennsylvanian system, lo- calities 6, 12, 13, 26, 38, 46, 53, 54, 55, 66, 67, 68, 71, 74, 81, 82, 88, 90, 102, 109, 113, 114, 115. Amphissites centronotus elongatus Payne Plate 15, figures 23-25 Amphissites centronatus elongatus Payne 1937, Jour. Paleontology, vol. 11, p. 280, pi. 38, figs. 2a-c; Hayden Branch forma- tion, Indiana. Carapace elongate, dorsal and ventral margins parallel, ends rounded, inner and outer carina tenuous, complete around free margins, parallel along ven- tral margin ; vertical carina distinct though low and thin, very long, about equidistant between edge of medial node and inner carinae ; node circular, of medium size, and slightly forward of center; pit ovate, axis inclined ante- riorly ; surface marked by irregular ret- iculations of small to medium size. Length, 0.82 mm; height, 0.41 mm; width, 0.45 mm. A. centronotus elongatus differs from A. centronotus by its unusual length (form ratio of 1.9 or greater). The Illi- nois specimens are identical with the KIRKBYIIDAE 99 Indiana form in all respects except that the vertical carinae are not continous around the node. Seahorne and Shoal Creek zones, local- ities 12, 74. Amphissites congruens Cooper, n. sp. Plate 15, figure 43 Carapace subquadrate, dorsal and ventral margins straight and parallel, ends rounded; inner carina low and in- distinct anteriorally, becoming more prominent, and gradually diverging from outer carina around ventral mar- gin to the posteroventral angle, where it disappears; posterior swelling distinct, surmounted by a false carina formed by ridge joining two rows of reticulations; median node fairly large, irregular in outline, located above and forward of oval pit ; axis of pit deflected to anterior, surface covered by reticulations of ir- regular shape, medium size, tending to- ward a regular alignment near the major features of shell sculpture. Length, 0.82 mm ; height, 0.48 mm. This species, occurring well up in the Pennsylvanian (Missouri series), is re- markably similar to two Chester species namely, A. golcondensis Croneis and Gale and A. quadratics Cooper from the Golconda and Kinkaid formations re- spectively. The Pennsylvanian species lack the convex ventral outline of A. gol- condensis and the retral swing of A. quadratics due to a difference in the car- dinal angles. The reticulate pattern of the Chester species seems finer and less regular. LaSalle zone, locality 88. Amphissites girtyi Knight Plate 15, figures 12-14 Amphissites girtyi Knight, 1928, Jour. Pale- ontology, vol. 2, p. 260, pi. 32, figs. 7a, b; pi. 34, fig. 1; Labette formation, Mis- souri. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 65, pi. 5, fig. 3; Wetumka formation, Oklahoma. — Cor- yell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 259, pi. 25, fig. 4; East Mountain shale, Texas. Amphissites mesacostata Roth, 1929, Wagner Free Inst. Sci., Publ. 1, p. 48, pi. 3, figs. 15a-c; Wetumka formation, Oklahoma. Carapace elongate, subquadrate, dor- sal margin straight, ventral margin dis- tinctly convex ; surface finely reticulate ; median node well forward of center, small ovate to elongate vertically; a horizontal costa extends anteriorly al- most to anteroventral costa; inner and outer keels high, distinct, narrow, with several rows of coarse reticulations be- tween them; pit circular, not much larger than coarsest reticulations, below and almost completely behind medial node. Length, 0.72 mm; height, 0.39 mm; width, 0.34 mm. A. girtyi is easily recognized by its horizontal costa extending from the node toward the anterior end and by the prominent smooth keels or carinae. This species ranges from the Seville to the Shoal Creek cyclothems in Illinois, where, as elsewhere, it is found most abundant in the zones of the upper Des Moines series. Localities 6, 11, 16, 22, 26, 29, 30, 41, 50, 54, 71, 77, 78 Amphissites parvus Cooper, n. sp. Plate 15, figures 3-6 Carapace small, irregularly ovate, posterior end slightly higher than ante- rior ; reticulations fine to medium ; cen- tral node small and directly over pit ; inner keel absent or poorly developed; vertical costa on each side of ventral node thin, short or absent entirely. Length (figs. 3, 4), 0.46; height, 0.26 mm; width 0.25 mm. This species resembles A. ciscoensis Harlton in size and in the lack of an inner ridge but the reticulations seem smaller and the cardinal angles are less obtuse. Seville and Oak Grove zones, localities 3, 4, 14. 100 PENN8YLVANIAN OSTRACODES Amphissites robustus Cooper, n. sp. Plate 15, figures 34-36 Carapace large, subquadrate, ends rounded, dorsal margin straight to con- vex, ventral margin straight; carinae prominent, though tenuous, inner one complete to cardinal angles ; vertical carinae long, straight to slightly curved ; posterior swelling very faint ; median node prominent, circular, and immedi- ately above ovate pit whose axis is hori- zontal ; surface reticulations irregularly polygonal and large to medium in size. Length, 0.97 mm; height, 0.57 mm; width, 0.56 mm. A. robustus closely resembles A. cen- tronotus (Ulrich and Bassler) but is more robust, less elongate and the node and pit are more centrally located. It appears to be very close to the Chester A. carinatus Cooper from the Golconda and Glen Dean, although the latter does not have the straight ventral margin. Gimlet to Macoupin zones, localities 60, 76, 84,85. Amphissites rothi Bradfield Plate 15, figures 26-28 Amphissites rothi Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 57, pi. 4, fig. 1; Dornick Hills formation, Oklahoma. Carapace subquadrate, cardinal an- gles obtuse, ends rounded, hinge straight and fairly short; nodes low and indis- tinct, posterodorsal node more promi- nent, sometimes obscuring cardinal an- gle; reticulations distinct, medium to coarse, and uniform in size ; pit on poste- roventral side of median node, ovate, with axis inclined sharply to anterior; carinae lacking or poorly developed be- tween the ventral angies only. Length, 0.90 mm; height, 0.51 mm; width, 0.48 mm. Although the medial node of Brad- field's species is slightly larger than those observed on some of the Illinois specimens, this feature appears to be variable, consequently the specimens are believed to be the same species, although occurring much higher in the section. Pokeberry to LaSalle zones, localities 53, 55, 64, 67, 68, 71, 73, 88. Amphissites roundyi Knight Plate 15, figures 7, 8 Amphissites roundyi Knight, 1928, Jour. Paleontology, vol. 2, p. 262, pi. 32, figs. 8a, b; pi. 34, fig. 5; Labette formation, Missouri. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 63, pi. 4, fig. 14; Wewoka formation, Oklahoma. — John- son, 1936, Nebraska Geol. Survey Paper 11, p. 31, pi. 3, figs. 29-31; Upper Mis- souri series, Nebraska. Carapace subquadrate, ends rounded, dorsal margin straight, ventral margin concave ; outer carina low, tenuous, forming margins between cardinal an- gles ; inner carina low, indistinct, irregu- lar, tenuous, parallelling central ventral margin, dying out at ventral extremi- ties; posterior swelling marked by a pseudocarinate ridge formed by the boundry between adjoining rows of reti- culations; median node low, inconspicu- ous, slightly back of center; pit central and on anteroventral margin of medial node ; surface marked by coarse deep reticulate network which is continous over surface of shell, uninterrupted by the medial node and inner carina. Length, 0.79 mm ; height, 0.45 mm ; width, 0.38 mm. The Nebraska specimens seem to be more elongate than those from Illinois and Missouri and possibly should be des- ignated as a variety (form ratio 1.66 compared to 1.77). Seahorne to "Centralia" zones, locali- ties 11, 20, 29, 38, 44, 81. Amphissites transversus Roth Plate 15, figures 1, 2 Amphissites centronata transversa Roth, 1929, Wagner Free Inst. Sci. Pub. 1, p. 52, pi. 3, figs. 17a-c; Francis formation, Oklahoma. Carapace large, subquadrate, ends rounded, hinge long; dorsal margin straight, ventral margin concave; cari- nae well developed but tenuous, inner carina extending' to cardinal angles, ver- tical carina developed to point even with KIRKBYIIDAE 101 lower side of median node ; node central immediately above oval pit with axis horizontal; surface covered by reticula- tions of medium size. Length, 0.82 mm; height, 0.46 mm; width, 0.48 mm. Seahorne to Summum zones, localities 9, 13, 22, 26. Genus Discoidella Croneis and Gale, 1938 Discoidella convexa? Scott and Borger Plate 16, figures 7, 8 Discoidella convexa Scott and Borger, 1941, Jour. Paleontology, vol. 15, p. 356, pi. 49, figs. 15, 16; Macoupin formation, Illi- nois. Carapace small, subcircular, valves convex, height slightly greater than length, greatest thickness above center on medial line ; surface sculpture and hingement obscured by poor preserva- tion. Length, 0.43 mm; height, 0.45 mm; width, 0.25 mm. Gimlet zone, locality 62. Discoidella lingulata Cooper, n. sp. Plate 16, figures 3, 4 Carapace small, ovate, convex, with a lateral outline and postcentral infla- tion resembling characteristic linguloid brachipods; dorsal margin sharply ar- cuate, ventral margin rounded, surface reticulate. Length, 0.41 mm; height, 0.50 mm; width, 0.27 mm. Macoupin to Shumway zones, locali- ties 83, 112. Discoidella perminuta? (Kellett) Plate 16, figures 5, 6 Paraparchites ? perminutus Kellett, 1933, Jour. Paleontology, vol. 7, p. 67, pi. 13, figs. 31, 32; Oread or Iatan limestone, Kansas. Off a? perminuta Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 48, pi. 5, fig. 10; Chanute shale, Nebraska. Carapace small, lateral outline irregu- larly subcircular; valves strongly con- vex, greatest thickness above center; surface finely reticulate. Length, 0.37 mm; height, 0.33 mm; width, 0.19 mm. These small almost featureless speci- mens seem to agree with Kellett 's de- scription and illustration and occur at a horizon comparable to that from which the Kansas form was obtained. Little Vermilion zone, locality 105. Genus Ectodemites Cooper, 1941 ECTODEMITES DATTONENSIS (Harlton) Plate 16, figures 1, 2 Amphissites dattonensis Harlton, 1927, Jour. Paleontology, vol. 1, p. 206, pi. 32, figs. 9a, b; Upper Glenn formation, Okla- homa. — Harlton, 1929, Texas Univ. Bull. 2901, p. 149, pi. 1, figs. 9a, b; Can- yon series, Texas. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 64, pi. 4, fig. 15; Wetumka, Wewoka, and Holdenville formations, Oklahoma. —Coryell and Billings, 1932, Am. Mid- land Naturalist, vol. 13, p. 184, pi. 18, fig. 8; Wayland shale, Texas. —Cor- yell and Sample, 1932, vol. 13, p. 260, pi. 25, fig. 2; East Mountain shale, Texas. —Kellett, 1933, Jour. Paleontol- ogy, vol. 7, p. 93, pi. 14, figs. 40-42; Howard formation, Kansas. — Coryell and Booth, 1933, Am. Midland Natural- ist, vol. 14, p. 260, pi. 3, fig. 3; Graham formation, Texas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 63, pi. 4, figs. 9a-c; Hoxbar formation, Okla- homa. • — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 29, pi. 3, figs. 16-19; Upper Pennsylvanian formations. Amphissites irregularis Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 261, pi. 25, fig. 5; East Mountain shale, Texas. Carapace subquadrate, dorsal margin straight to somewhat convex, ventral margin concave ; surface coarsely reticu- late ; median node absent ; pit below mid- dle, equidistant from extremities, axis inclined anteriorly; posterior shoulder marked by thin, almost vertical costa; inner keel low, indistinct, and only about half as long as shell. Length, 0.85 mm; height, 0.46 mm; width, 0.42 mm. 102 PENNSYLVANIAN OSTRACODE8 E. dattonensis can be distinguished by the tenuous shoulder bordering the de- pressed posterior and by the lack of well developed medial node or of an anterior carina. Ferdinand to Woodbury zones ; locali- ties 2, 20, 22, 26, 30, 36, 37, 50, 54, 55, 79, 81, 83, 84, 88, 92, 93, 102, 107, 109, 115. Ecotedemites edsonae (Bradfield) Plate 16, figures 15-17 Amphissites edsonae Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 62, pi. 4, fig. 7; Hoxbar formation, Oklahoma. Carapace subquadrate, ends rounded, dorsal margin straight, ventral margin straight to slightly convex; greatest height anterior ; inner carinae absent ; position of median node marked by a short vertical costa, located just ahead of ovate node, whose axis is inclined anteriorly about 45° ; surface reticulate. Length, 0.59 mm; height, 0.36 mm; width, 0.20 mm. E. edsonae closely resembles E. dat- tonensis (Harlton) in general shape and outline, but is distinguished by the ab- sence of an inner carina. Woodbury zone, locality 115. ECTODEMITES HARLTONI Cooper, n. Sp. Plate 15, figure 44 Amphissites sp. Harlton, 1933, Jour. Paleon- tology, vol. 7, p. 23, pi. 6, fig. 6; Johns Valley shale, Oklahoma. Carapace subrectangular, cardinal an- gles obtuse, dorsal and ventral margins straight and parallel ; surface marked with very coarse irregular polygonal reticulations; two swellings, one nearly central, the other in posterocardinal an- gle, are covered with similar reticula- tions that are not interrupted by the nodes or swellings ; pit small, ovate, and indistinct because of coarse reticulation ; inner keel subparallel to outer, closest anteriorly. Length, 0.97 mm ; height, 0.60 mm. E. harltoni is similar in every respect to the specimen described by Harlton from the Johns Valley shale, except that the Illinois specimens are slightly smaller. Fukla and Seville zones, localities 1, 7. ECTODEMITES GENEAE (Roth) Plate 15, figures 32, 33 Amphissites geni Roth, 1929, Wagner Free Inst. Sci.,Publ. 1, p. 42, pi. 12, figs, 12a-e; Francis formation, Oklahoma. Amphissites geneae, Warthin, 1930, Okla- homa Geol. Survey Bull. 53, p. 64, pi. 5, fig. 2; Holdenville formation, Oklahoma. Amphissites gregeri Delo, 1931, Washington Univ. (St. Louis) Studies, n. ser., Sci. Tech. 5, p. 48, pi. 4, figs. 8a-c; Pennsyl- vanian, Kansas. Cy there? haworthi Ulrich and Bassler, 1906, U. S. Nat. Mus. Proc. vol. 30, p. 160, pi. 11, fig. 12; Cottonwood shale, Kansas. Amphissites minuta Roth, 1929, Wagner Free Inst. Sci., Publ. 1, p. 44, pi. 2, figs. 13a-c; Francis formation, Oklahoma. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 43, pi. 3, figs. 12a-c; Florena and Cottonwood formations, Nebraska. Amphissites pinguis Ulrich and Bassler, 1906, U. S. Nat. Mus. Proc, vol. 30, p 159, pi. 11, figs. 13-15; Cottonwood shale, Kansas. ■ — Knight, 1928, Jour. Paleon- tology, vol. 2, p. 263, pi. 32, fig. 9; pi. 34, fig. 3; Labette formation, Missouri. — Delo, 1931, Washington University (St. Louis) Studies, n. ser., Sci. Tech. 5, p. 46, pi. 4, figs. 7a-c; Pennsylvanian, Kansas. — Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 260, pi. 25, fig. 3; East Mountain shale, Texas. — Kellett, 1933, Jour. Paleontol- ogy, vol. 7, p. 94, pi. 15, figs. 12-22, 41; Dover to Wreford formations, Kansas. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 43, pi. 3, figs. 11a, b; Garrison shale, Nebraska. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 61, pi. 4, fig. 6, Hoxbar group, Oklahoma. Carapace ovate, dorsal margin straight, venter convex; carinae absent; median node low, indistinct, and directly above oval pit ; posterior shoulder faint ; surface covered with small reticulations. Length, 0.91 mm; height, 0.54 mm; width, 0.50 mm. This species which ranges in age from Ft. Scott to Permian in the Mid-Conti- nent region, has been found only in the Millersville zone in Illinois, locality 90. KIEKBYIIDAE 103 Ectodemites plummeri Cooper, n, sp. Plate 15, figures 37-42 Carapace short, tumid; lateral outline ovate or subrectangular ; dorsal margin straight, ventral slightly convex; ends subequally rounded; cardinal angles nearly 90°, ventral corners rounded; posterior shoulder promient, extending above dorsal margin; center of shell in- flated, in some almost nodular; inner carina low, thin, and very inconspicuous, and subparallel to margin ; surface coarsely reticulate ; pit oval and slightly back of center. Length (holotype), 0.75 mm; height, 0.46 mm ; width, 0.44 mm. Ferdinand formation, locality 2. (Holotype from Marble Falls formation, San Saba County, Texas; Mrs. Helen J. Plummer, locality 2103E). Ectodemites sullivanensis (Payne) Plate 16, figures 9, 10 Amphissites sullivanensis Payne, 1937, Jour. Paleontology, vol. 11, p. 281, pi. 38, figs. 3a-c, 4; Hayden Branch formation, Indiana. Carapace elongate, dorsal and ventral margins straight, ends rounded ; greatest height anterior; carinae absent except for a faint development along ventral margin ; central node and posterior swelling little developed ; pit ovate, sub- central, axis inclined anteriorly ; surface reticulations small. Length, 0.85 mm ; height, 0.45 mm ; width, 0.38 mm. This species is characterized by its greater proportional length and by the small size of the reticulations. The fig- ured specimen is compressed vertically and appears more elongate than the holotype. Millersville zone, locality 90. Genus Kellettina Swartz (1936) Kellettina montosa (Knight) Plate 16, figures 23-26 Ulrichia montosa Knight, 1928, Jour. Paleon- tology, vol. 2, p. 252, pi. 32, figs, la, b; pi. 33, fig. 1; Labette formation, Mis- souri. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 62, pi. 4, fig. 13; Wewoka formation, Oklahoma. — Brad- field, 1935, Bull. Am. Paleontology, vol. 22, p. 53, pi. 3, figs. 9, lla-c; Deese group, Oklahoma. — Johnson, 1936, Ne- braska Geol. Survey Paper 11, p. 34, pi. 3, figs. 1-3; Stanton and Iola formations, Nebraska. Carapace elongate, semiovate in later- al view; dorsal margin long, straight to slightly convex; ventral margin convex; posterior margin flat in upper portion, curving around ventral portion to meet the ventral margin ; anteroven- tral curve broader, involving the entire anterior margin, meeting dorsal margin at an acute angle ; nodes large, reticu- late, circular to ovate, anterior nodes usually projecting above hinge line ; flange prominent, thick, wide; surface coarsely reticulate; pit fairly large, ovate, and on anteroventral margin of posterior node. Length, 1.08 mm; height, 0.54 mm; width, 0.53 mm. Seahorne to Macoupin zones, localities 12, 26, 29, 30, 53, 54, 62, 85. Kellettina robusta? (Kellett) Plate 16, figures 11-14 Ulrichia robusta Kellett, 1933, Jour. Paleon- tology, vol. 7, p. 92, pi. 15, figs. 33-40, 42; Wreford formation, Kansas. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 45, pi. 4, fig. la; Wreford and Fourmile limestone, Nebraska. — Swartz, 1936, Jour. Paleontology, vol. 10, p. 585, pi. 87, fig. 9. Kellettina vidriensis Hamilton, 1942, Jour. Paleontology, vol. 16, p. 714, pi. 110, fig. 9; Word limestone, Texas. Carapace large, elongate, semiovate ; dorsal margin straight; ventral margin strongly convex; curvature of end mar- gins subequal ; cardinal angles acute, an- terior angle slightly more so ; nodes large, elongate, especially the anterior which projects well above the hinge ; sur- face coarsely reticulate ; flange fairly wide, smooth, and stands abruptly up from shell surface. 104 PENNSYLVANIAN OSTBACODES Length, 1.05 mm; height, 0.59 mm; width, 0.46 mm. The small variation in the character of the frill described by Hamilton is not considered to be a specific distinction. Gimlet to Little Vermilion zones, lo- calities 61, 62, 88, 98, 102. Genus Kirkbya Jones, 1859 The recognition of species of Pennsyl- vanian Kirkbya is difficult for several reasons. The shells are comparatively thin and, as a result, a large number of specimens are broken, crushed, or other- wise distorted. Only exceptional shale samples contain a sufficiently large num- ber of specimens for comparison of the various moult stages, consequently a number of species have been described on immature forms. Different species vary inconsistently through the instars, so that unless a complete series is present in a sample it is often impossible to rec- ognize immature forms specifically. For example, in Kirkbya valid a Kellett the surface features become less and less conspicuous from adult to immature specimens; the lateral outline becomes less rectangular and more semicircular and the shoulder less prominent, finally all but disappearing in the youngest stages. On the other hand, in K. kellet- tae Harlton the shoulder and convolu- tions in the center of the shell become more pronounced from old to young in- stars, whereas the lateral outline varies but little. It has been my observation that most adult shells are one millimeter or more in length, and any Pennsyl- vanian specimen less than 1 mm. long should be considered immature unless the study of a complete moult series proves it to be otherwise. Kirkbya arcuata ? Roth Plate 16, figures 31-34 Kirkbya arcuatum Roth, 1929, Wagner Free Inst. Sci., Publ. 1, p. 18, pi. 1, fig. 3a; Nellie Bly formation, Oklahoma. Carapace semiovate, dorsal margin slightly convex, ventral margin flat in posterior, thick and curving upward to meet dorsal margin at unequal angles, resulting in a much broader curve on anteroventral margin ; flange heavy, fairly wide, separated from, but not par- allel to, the free margins ; surface broad- ly inflated and coarsely reticulate; shoulder not conspicuous; pit small and ovate. Length, 1.13 mm; height, 0.57 mm; width 0.48 mm. The form figured by Koth is probably an immature moult as it is smaller than most adult specimens of Kirkbya. Shoal Creek and LaSalle zones, locali- ties 76, 77, 93. Kirkbya bendensis Harlton Plate 16, figures 27-30 Kirkbya bendensis Harlton, 1933, Jour. Paleontology vol. 7, p. 22, pi. 6, fig. 2 ; Johns Valley shale, Oklahoma. — Bradfield, 1935, Bull. Am. Paleontol- ogy, vol. 22, p. 50, pi. 3, fig. 5; Dornick Hills group, Oklahoma. Carapace small, semiovate; dorsal margin almost straight, bent slightly down toward posterior near shoulder; ventral margin slightly convex, bending upward to meet dorsal margin at high angles (90° or nearly so) ; flange wide, prominent, and parallel to free margins ; shoulder moderately abrupt ; pit small and nearly central; surface coarsely reticulate. Length, 0.97 mm; height, 0.49 mm; width, 0.40 mm. Fulda to Seville zones, localities 1, 3, 6. Kirkbya firma Kellett Plate 16, figures 36, 37 Kirkbya firma, Kellett, 1933, Jour. Paleon- tology, vol. 7, p. 87, pi. 14, figs. 9. 10; Stanton formation, Kansas. Kirkbya permiana, Roth, 1929 (not Jones) Wagner Free Inst. Sci., Publ. 1, p. 21, pi. 1, figs. 5a-c; Belle City formation, Okla- homa. Kirkbya permiana varica Roth, 1929, idem, p. 25, pi. 1, figs. 6a-c; Francis formation, Oklahoma. KIRKBYIIDAE 105 Carapace elongate; hinge line long and straight; ventral margin convex; ends rounded, anterior cardinal angle 90°, posterior angle acute ; flange low, smooth, subparallel to free margin ; sur- face uniformly covered by reticulations of medium size; pit small, subcircular, and central. Length, 0.97 mm; height, 0.51 mm; width, 0.42 mm. Jamestown to Woodbury zones, lo- calities 52, 53, 76, 77, 83, 102, 113, 114, 115. KlRKBYA INORNATA Roth Plate 16, figures 18-20 Kirkbya inornatum Roth, 1929, Wagner Free Inst. ScL, Publ. 1, p. 14, pi. 1, figs, la-c; Wapanucka limestone, Oklahoma. Kirkbya cf. K. inornata, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 52, pi. 3, fig. 10; Dornick Hills group, Okla- homa. Kirkbya sp. Bradfield, 1935, idem, p. 53, pi. 3, fig. 7; Dornick Hills group, Oklahoma; probably a young specimen. Carapace elongate; dorsal margin nearly straight, except over shoulder; ventral margin convex, curving uni- formly upward at ends to meet dorsal margin at almost equal angles, posterior angle slightly more acute; flange thin, regular, and parallel to free margins ; shoulder only moderately developed, curvature of shell uniform; pit slightly anterior to center ; surface marked by reticulations of medium size. Length, 1.08 mm; height, 0.50 mm; width, 0.46 mm. Seville and Seahorne zones, localities 4, 12. Kirkbya kellettae Harlton Plate 16, figures 38-42 Kirkbya kellettae Harlton, 1929, Texas Univ. Bull. 2901, p. 152, pi. 2, figs. 2a-e; Canyon series, Texas. Kirkbya canyonensis Harlton, 1929, idem, p. 153, pi. 2, figs. 5a, b; Canyon series, Texas. — Kellett, 1933, Jour. Paleon- tology, vol. 7, p. 89, pi. 15, figs. 1-7; Stan- ton limestone, Kansas. — Scott and Bor- ger, 1941, Jour. Palentology, vol. 15, p. 356, pi. 49, fig. 21; Macoupin formation, Illinois. Kirkbya knighti Harlton, 1929, Texas Univ. Bull. 2901, p. 153, pi. 2, figs. 4a, b; Can- yon series, Texas. — Johnson, 1936, Ne- braska Geol. Survey Paper 11, p. 27, pi. 3, figs. 9-11, Stanton f ormation, Ne- braska. Carapace subrectangular ; hinge line straight ; ventral margin slightly convex, almost straight and subparallel to dorsal margin ; ends subequally and slightly rounded, cardinal angles obtuse ; surface reticulate, with shell curvature inter- rupted by wavy or knobby undulations; flange wide, smooth and prominent ; pit small and nearly central; posterior shoulder prominent. Length, 0.93 mm ; height, 0.46 mm ; width, 0.43 mm. This pecies, formerly reported only from the Missouri series is now known to extend down in the Pennsylvanian sec- tion to the Seahorne and Fulda zone of the Illinois basin and the Barnett Hill and Marble Falls formations of the Mid- continent. K. canyonensis, K. knighti, and K. kellettae appear to be moult stages of a single species, since they were described by Harlton (1929, pp. 151- 152) from one horizon and locality. Fulda to Bogota zones, localities 1, 2, 3, 44, 83, 84, 97. Kirkbya magna Roth Plate 16, figure 35 Kirkbya magnum Roth, 1929, Wagner Free Inst. Sci., Publ. 1, p. 16, pi. 1, figs. 2a, b; Wapanucka limestone, Oklahoma. Carapace large, hinge line long and nearly straight; ventral margin very convex, rounding broadly toward ends, anterior and posterior curvature almost equal, terminating in flaring, wing-like cardinal angles; shell surface strongly inflated in midportion, decreasing rap- idly to form a broad distinctly concave area bordering the very wide prominent flange ; pit large, subcentral ; surface re- ticulations moderate in size. Length, 1.28 mm ; height, 0.62 mm. Ferdinand to Brereton zones, locali- ties 2, 4, 38. 10(i PENN8YLVANIAN OSTRACODKS KlRKBYA PERGRANDIS Kellett Plate 17, figure 10 Kirkbya pergrandis Kellett, 1933, Jour. Pale- ontology, vol. 7, p. 85, pi. 14, fig. 31; Stanton and Deer Creek formations, Kansas. Carapace very large, elongate ; ventral margin straight to broadly convex, curv- ing widely at ends to meet dorsal margin at subequal angles, posterior more acute ; flange wide, smooth, and extends far be- yond free margins; shoulder very prominent; surface smooth? to finely reticulate. Length, 2.05 mm ; height, ca. 0.75 mm. Lonsdale zone, locality 63. KlRKBYA PUNCTATA Kellett Plate 17, figures 5-8 Kirkbya punctata Kellett, 1933, Jour. Paleon- tology, vol. 7, p. 87, pi. 14, figs. 46-49; Stanton formation, Kansas. — Scott and Borger, 1941, idem, vol. 15, p. 356, pi. 49, fig. 6; Macoupin formation, Illinois. Kirkbya clarocarinata, Johnson, 1936 (not Knight), Nebraska Geol. Survey Paper 11, p. 24, pi. 3, figs. 22-24; Iola to Stan- ton formation, Nebraska. Kirkbya clarocarinata (part), Harlton, 1929, Texas Univ. Bull. 2901, p. 152, pi. 2, figs. 3c, d, g, h (not 3a, b, e, f); Upper Canyon series, Texas. — Kellett, 1933, Jour. Paleontology, vol. 7, p. 86, pi. 14, figs. 50, 52, 53 (not 51); Stanton lime- stone, Kansas. Carapace of medium size, semiovate in lateral outline ; hinge line straight and somewhat incised; dorsal margin arched over shoulder; ventral margin nearly straight in central portion, curv- ing broadly upward to meet dorsal mar- gin at obtuse nearly equal angles ; flange low, marginal; shoulder fairly promi- nent; pit of moderate size, ovate, and well anterior to midpoint ; surface retic- ulations fairly coarse. Length, 1.16 mm; height, 0.57 mm; width, 0.56 mm. There is considerable difference of opinion concerning the discrimination of K. clarocarinata Knight and K. punc- tata Kellett, there being no uniform spe- cific critera given in the descriptions of these species. Johnson (1936, p. 26) did not consider the size and shape of the pit of importance while Kellett (1936, p. 780) believed this feature to be constant for all moults of a species, and therefore important in specific deter- minations. However considering other features, such as lateral outline, position of flange, development of shoulder, and cardinal angles, it appears that these species are distinct. K. clarocarinata from the Labetta shale has more acute cardinal angles, little development of the shoulder, a flange much higher on the shell. Little or no variation in curvature at the poste- roventral angles gives the lateral outline a semicircular appearance. Macoupin to Woodbury zones, locali- ties 84, 89, 93, 115. Kirkbya reflexa Girty Plate 17, figures 1-4 Kirkbya reflexa Girty, 1910, New York Acad. 1910, New York Acad. Sci. Trans., vol. 20, p. 235; Fayetteville shale, Arkansas, not Kirkbya cf. K. reflexa Cooper, Illinois Geol. Survey, Rept. Invest. 77, p. 47, pi. 10, figs. 27, 28. Carapace large, inflated; dorsal mar- gin straight, ventral margin convex; ends nearly equal; usual shoulder ab- sent ; surface coarsely reticulate, frill broad, fluted ; strongly reflexed, forming a trough parallel to the contact margins ; pit oval, and central, just below point of highest inflation. Length, 1.0 mm ; height, 0.54 mm. Fulda zone, locality 1. Genus Kirkbyella Coryell and Booth, 1933 Kirkbyella cf. K. gutkei Croneis and Bristol Plate 17, figure 9 Kirkbyella gutkei Croneis and Bristol, 1939, Denison Univ. Bull. Jour. Sci. Lab., vol. 34, p. 84, pi. 4, figs. 14, 15; Menard form- ation, Illinois. — Cooper, 1941, Illinois Geol. Survey Rept. Invest. 77, p. 18, pi. 10, figs. 20, 21; Glen Dean to Clore form- ations, Illinois. KIBKBYIIDAE 107 Carapace small; lateral outline ovate, dorsal margin straight ; ventral margin slightly convex, ends rounded ventrally, straightening upward to form cardinal angles slightly in excess of 90° ; sulcus central, vertical, wide, and fairly deep ; ventral ridge wide, low, and inconspicu- ous; terminated abruptly posteriorly. Length, 0.56 mm ; height, 0.31 mm. The single valve figured has been flat- tened and broken, the distortion result- ing in a greater relative height than in the Chester forms, otherwise they are similar. Fulda zone, locality 1. Genus Knightina Kellett, 1933 Knightina allerismoides (Knight) Plate 17, figure 12 Amphissites allerismoides Knight, 1928, Jour. Paleontology, vol. 2, p. 265, pi. 32, figs. lOa-c; pi. 34, fig. 4; Labette forma- tion, Missouri. Carapace elongate, outline subquad- rate, dorsal margin straight, ventral mar- gin convex ; inner carina prominent and close to outer one; posterior shoulder moderate; pit ]arge, ovate, subcentral, though somewhat indistinct because of the extremely coarse reticulation. Length, 0.75 mm ; height, 0.37 mm. K. allerismoides is distinguished by its coarse reticulation, large form ratio (2.0), and by the prominent, closely spaced carinae. Liverpool zone, locality 20. Knightina ampla Kellett Plate 17, figure 11 Knightina ampla Kellett, 1933, Jour. Paleon- tology, vol. 7, p. 100, pi. 16, figs. 43-46; Deer Creek formation, Kansas. Kirkbya perplexa Roth, 1929, Wagner Free Inst. Sci. Publ. 1, p. 29, pi. 1, figs. 8a-c; Belle City formation, Oklahoma. Knightina texana, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 64, pi. 4, fig. 8; Hoxbar group, Oklahoma. Knightina harltoni, Payne, 1937 (not Kellett, 1933), Jour. Paleontology, vol. 11, p. 281, pi. 38, figs. 7a, b; Hayden Branch forma- tion, Indiana. Carapace elongate, subquadrate, dor- sal and ventral margins subparallel, ends almost equally rounded, posterior end slightly more acute ; inner carina marginal and very close to outer one which is somewhat indistinct; posterior shoulder prominent; pit subcentral, cir- cular ; reticulation coarse, irregular, ovate to polygonal. Length, 0.77 mm ; height, 0.38 mm. The subparallel dorsal and ventral margins, the subequal rounded ends, coarse reticulation and almost circular, subcentral pit mark this Upper Pennsyl- vanian species and serve to distinguish it from those in younger and older forma- tions. Little Vermilion zone, locality 103. Knightina harltoni Kellett Plate 17, figures 14-16 Knightina harltoni Kellett, 1933, Jour. Pale- ontology, vol. 7, p. 99, pi. 16, figs. 1-7; Stanton formation, Kansas. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 33, pi. 3, figs. 25-28; Upper Missouri series, Nebraska. Not Knightina harltoni, Payne, 1937, Jour. Paleontology, vol. 11, p. 281, pi. 38, figs. 7a, b. Carapace short, subquadrate, ends rounded, dorsal and ventral margins almost straight, subparallel ; shoulder prominent but rising little above dorsal margin; inner carina marginal, sepa- rated from outer by two rows of reticu- lations; pit oval, subcentral; reticula- tion coarse and fairly uniform in size and shape. Length, 0.72 mm ; height, 0.41 mm ; width, 0.36 mm. The relatively low form ratio (1.7 to 1.8), coarse, uniform reticulation, large pit surrounded by 8 reticulations serve to differentiate this species. Millersville zone, locality 90. 108 PENNSYLVANIAN OSTRACODES Knightina iiextensis (Harlton) Plate 17, figures 17, 18 Amphissites Iiextensis Harlton, 1929, Texas Univ. Bull. 2901, p. 152, pi. 2, figs. 6a-d; Canyon group, Texas. Carapace small, very elongate, tumid, dorsal and ventral margins straight, sub- parallel, greatest height anterior; ends rounded ; inner carina submarginal, sep- arated from outer by two rows of reticu- lations, diverging slightly anteriorally due to an enlargement of reticulations ; pit subcentral, surrounded by 8 reticuli. Length, 0.64 mm ; height, 0.31 mm ; width, 0.28 mm. K. Iiextensis is characterized by its large form ratio (2.0 to 2.08), its great- est height anterior, and by the divergent carinae. Gimlet zone, locality 57. Knightina kellettae Bradfield Plate 17, figure 13 Knightina Kellettae Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 65, pi. 4, fig. 10; Dornick Hills group, Oklahoma. Carapace large, elongate ; dorsal mar- gin straight except where interrupted by prominent posterior shoulder, ventral margin slightly convex, almost straight; anterior end straight at cardinal angle of slightly more than 90°, posterior end rounded and extended; carinae distinct, closely spaced; pit subcentral, small, ovate, axis almost horizontal ; reticula- tions large irregularly polygonal. Length, 0.83 mm ; height, 0.46 mm. Liverpool zone, locality 22. Genus Polytylites Cooper, 1941 POLYTYLITES WAPANUCKENSIS (Harlton) Plate 16, figures 21-22 Amphissites wapanuckensis Harlton, 1929, Am. Jour. Sci., ser. 5, vol. 8, p. 257, pi. 1, figs. 4a, b; Wapanucka limestone, Oklahoma. —Harlton, 1933, Jour. Pale- ontology, vol. 7, p. 23, pi. 6, fig. 8; Johns Valley shale, Oklahoma. Carapace small ; lateral outline ovate ; dorsal margin straight; ventral margin convex ; ends subequally rounded and of unequal height ; contact margins border- ed by a thin, low carina, the centroven- tral region bordered by a high, promi- nent inner carina half as long as the shell or more ; central node circular, of moderate diameter and high ; anterior node of slightly lesser diameter, very long, projects well above dorsal margin ; pit ovate, immediately below central node ; surface reticulate. Length, 0.90 mm ; height, 0.54 mm. Fulda limestone, locality 1. Genus Roundyella Bradfield, 1935 Roundyella Bradfield, 1935, p. 66. Scaberina Bradfield, 1935, p. 67. The genotypes of Roundyella and Scaberina are single valves; in one (Roundeyella) the shell appears to have been scoured smooth and all spines re- moved leaving only the reticulation showing. In Scaberina the surface re- ticulation is matrix filled, leaving only the spines protruding. A comparison of the hinge and shape of the valves shows their similarity, in fact the genotypes Scaberina nodomarginata Bradfield and R. simplicissima (Knight) are believed to be conspecific. R. bellatula proba- bly does not belong to this genus because of the extreme roundness of the cardinal angles and the distinct pit as contrasted to the flat area marking the muscle spot on the characterisic forms of Roundyella. Roundyella simplicissima (Knight) Plate 17, figures 29-36 Amphissites simplicissimus Knight, 1928, Jour. Paleontology, vol. 2, p. 266, pi. 32, figs, lla-d; pi. 34, fig. 6; Labette shale, Missouri. —Harlton, 1929, Texas Univ. Bull. 2901, p. 151, pi. 1, figs. 13a-c; Can- yon group, Texas. ? — Delo, 1930, Jour. Paleontology, vol. 4, p. 158, pi. 12, figs. 8a, b; Pennsylvanian, Texas. — Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 67, pi. 5, figs, la, b; Wetumka to Hold- enville formations, Oklahoma. — Coryell and Billings, 1932, Am. Midland Natural- KLOEDENELLIDAE 109 ist, vol. 13, p. 184, pi. 18, fig. 10, Wayland shale, Texas. — Kellett, 1933, Jour. Paleontology, vol. 7, p. 97, pi. 15, fig. 8; Elmdale formation, Kansas. — Upson, 1933, Nebraska Geol. Survey Bull. 8, p. 41, pi. 3, figs. 6a; Garrison shale, Ne- braska. Not Amphissites simplicissimus Coryell and Malkin, Am. Mus. Noviates, no. 891, p. 4, fig 11. Roundyella simplicissimus, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 66. — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 32, pi. 3, figs. 7, 8; Stanton formation, Nebraska. Carapace small, elongate, flat; lateral outline elliptical; dorsal and centroven- tral margins straight; ends of equal height, equally rounded ; cardinal angles abrupt, ventral angles broadly rounded ; hinge straight, slightly incised and ter- minated at each end by indistinct notch ; muscle attachment marked by a compar- atively smooth flat area slightly forward of center; surface reticulate, papillose or both. Length (figs. 31, 32), 0.74 mm; height, 0.39 mm ; width, 0.30 mm. Wiley to Greenup zones, localities 4, 13, 16, 28, 38, 40, 45, 54, 60, 102, 109, 113. Family Kloedenellidae Ulrich and Bassler, 1923 Genus Ellipsella Coryell and Eogatz, 1923 Lochriella Scott (1942, p. 155) ap- pears to be very nearly equivalent to Ellipsella, and further study may show that the two genera are synonomous. Although the lateral outlines differ somewhat in shape, the type of overlap around the contact margins and the character of the hingement are similar, particularly in the development of a flap-like overlap at the posterior end of the hinge. Species in each genera have been described both with and without sulci. Ellipsella calcar (Harlton) Plate 17, figures 24-28 Cytherella calcar Harlton, 1928, Jour. Paleon- tology, vol. 2, p. 141, pd. 21, figs. 16a, b; Graham formation, Texas. — Harlton, 1929, Texas Univ. Bull. 2901, p. 161, pi. 4, fig. 9; Canyon series, Texas. Jonesina acuneata Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 61, pi. 4, figs. 9a, b; Wetumka formation, Oklahoma. — Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 254, pi. 24, fig. 10; East Mountain shale, Texas. Jonesina ampla Warthin, 1930, idem, p. 61, pi. 4, figs. 8a, b; Holdenville formation, Oklahoma. ■ — Coryell and Sample, 1932, idem, p. 255, pi. 24, fig. 14, East Moun- tain shale, Texas. Jonesina hoxbarana Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 40, pi. 2, figs. 10a, b; Hoxbar group, Oklahoma. fJonesina mccoyi Roth, 1930, Jour. Paleon- tology, vol. 4, p. 348, pi. 2, figs. 10a, b; McCoy formation, Colorado. Ellipsella ampla, Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 23, pi. 2, figs. 8-10; Chanute shale, Nebraska. Ellipsella? distenta Kellett, 1933, Jour. Pale- ontology, vol. 7, p. 82, pi. 13, figs. 18-20; Stanton to Winfield formations, Kansas. Ellipsella calcar, Kellett, 1936, Jour. Paleon- tology, vol. 10, p. 772. Carapace small, tumid ; lateral outline subelliptical ; dorsal and ventral margins nearly straight ; ends subequally round- ed, of nearly equal height; overlap in- conspicuous around ends, fairly wide along ventral margin ; line of concre- scence incurved along venter and poste- rior margins ; hinge line relatively short, straight, incised in gradually widening furrow on posterior end, and terminated anterior] y by a pronounced overlap of right valve over left ; sulcus fairly wide, shallow, and centrally constricted ; greatest height and width posterior ; sur- face smooth to faintly punctate. Female : length, 0.84 mm ; height, 0.46 mm; width, 0.42 mm. Male: length, 0.80 mm; height, 0.46 mm ; width, 0.32 mm. Gimlet to Newton zones, localities 1, 62, 63, 65, 66, 86, 100, 107, 108. 110 PENNSYLVANIAN OSTRACODES ELLIPSELLA BRADFIELDI Cooper, 11. Sp. Plate 17, figures 19, 20 Jonesina craterigera, Ulrich and Bassler, 1908, (not Brady), U. S. Nat. Mus. Proc, vol. 35, p. 324, pi. 44, figs. 13, 14; Lower Glenn, Oklahoma. — H a r 1 1 o n , 1927, Jour. Paleontology, vol. 1, p. 205, pi. 32, figs. 5a, b; Lower Glenn, Oklahoma. Carapace elongate, semiovate in later- al outline; hinge line long, straight; ends rounded; ventral margin convex; overlap wide along venter, moderate around ends; sulcus wide, shallow, and indistinct. Length, 0.72 mm; height, 0.36 mm; width, 0.33 mm. The original Beyrichia craterigera Brady from the Carboniferous (lower Chester) of Great Britian is larger and has somewhat different outlines in lat- eral and dorsal views than the elongate Pennsylvania^ forms. The anterodorsal overlap is characteristic of Ellipsella. Liverpool and Brereton zones, locali- ties 20, 47. Genus Geisina Johnson, 1936 Geisina gallowayi (Bradfield) Plate 17, figures 21-23 Jonesina gallowayi Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 39, pi. 2, figs. 8a, b; Deese group, Oklahoma. Carapace subrectangular, ends rounded, ventral margin curved at ends, and straight in center due to thickening of the edge of right valve ; sulcus deep, U-shaped in cross-section, slightly con- stricted in central part, flaring at top ; channel along posterodorsal area wide, very shallow; overlap prominent and uniform, except along" thickened portion of ventral edge of right valve; surface smooth. Length, 0.95 mm; height, 0.57 mm; width, 0.48 mm. Brereton zone, locality 48. Geisina gregaria (Ulrich and Bassler) Plate 18, figures 1, 2 Beyrichiella gregaria Ulrich and Bassler, 1906, U. S. Nat. Mus. Trans., vol. 30, p. 157, pi. 11, fig. 18. Jonesina gregaria, Ulrich and Bassler, 1908, idem, vol. 35, p. 325, pi. 44, fig. 6. — Harl- ton, 1928, Jour. Paleontology, vol. 2, p. 134, pi. 21, figs. 4a, b; Upper Glenn (Con- federate limestone) formation, Okla- homa. —Knight, 1928, idem, p. 241, pi. 31, figs. 5a-f; Labette formation, Mis- souri. ? — Delo, 1931, Washington Univ. (St. Louis) Studies new ser., Sci. and Tech. no. 5, p. 43, pi. 4, figs. 3a, b. —Bradfield, 1935, Bull. Am. Paleontol- ogy, vol. 22, p. 42, pi. 2, figs. 12a, b. — Johnson, 1941, Nebraska Geol. Survey Paper 11, p. 22, pi. 2, figs. 11-14; Kansas City group, Nebraska. Carapace elongate, hinge line straight, ends rounded, ventral margin convex; sulcus deep, anterior to center, inclined toward anterior end, upper part flaring to form low area around anderodorsal angle, outlining the node in the centro- anterior area ; spine in posterodorsal an- gle short and directed upward and slightly outward; surface smooth. Length, 0.85 mm ; height, 0.51 mm. This species is distinguished from G. arcuata (Bean) by the presence of the spine in the posterodorsal angle. The reticulate surface appears to be preserv- ed only on the more perfect specimens. Brereton and Jamestown zones, local- ities 48, 52. Geisina jolliffina Cooper, n. sp. Plate 18, figures 3, 4 Jonesina arcuata, Harlton, 1927, Jour. Pale- ontology, vol. 1, p. 205, pi. 32, figs. 6a-c; Lower Glenn (Jolliff limestone) forma- tion, Oklahoma. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 38, pi. 2, fig. 6 (? fig. 7); Jolliff limestone, Dor- nick Hills group, Oklahoma. Carapace short, convex, hinge line straight, but topped by swollen valve in posterior half, giving the dorsal outline a sinuous appearance ; anterior end rounded ; posterior end straight near dorsal angle of almost 90°, and curving from the midportion to meet the regu- KLOEDENELLIDAE 111 larly convex ventral margin; ventral and anterior margins bordered by a prominent but narrow flange ; sulcus deeply incised, slightly anterior to mid- portion, somewhat flaring at lower end ; surface uniformly covered by polygonal reticulations. Length, 0.87 mm ; height, 0.51 mm. There is considerable variation in the form ratio of this species (1.50-1.70), within which Bradfield's specimen falls. Bradfield's drawing does not show the marginal flange, which is much less prominent than on the Illinois speci- mens. Jamestown zone, locality 52. Geisina warthini Cooper, n. sp. Plate 18, figure 5 Jonesina gregaria, Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 60, pi. 4, fig. 11; Wewoka formation, Oklahoma. Carapace very short, semicircular, convex; hinge line straight, channelled in posterior half; ventral margin con- vex ; posterior end slightly less convex than anterior; sulcus just anterior to center, deep, flaring at upper anterior to form a low shelf bordering hinge ; short spine high in posterodorsal angle; sur- face smooth to finely granulose. Length, 0.66 mm ; height, 0.46 mm. Warthin 's specimen is probably a male as his drawing shows no proturb- ence of the posterodorsal swelling above the hinge. Hanover to Jamestown zones, locali- ties 28, 52. Genus Hastifaba Cooper, n. gen. Large, tumid kloedenellids with deep prominent sulcus forward of midlength, and greatly inflated posterior which may be extended dorsally into a short round- ed spine protruding well above the hinge line; hingement sansabelloid ; contact margin of left valve simple, sharp edged, fitting into rabbeted margin of right valve ; often a short, round spine is de- veloped on the margin of each valve near anterior extremity; overlap prominent, especially along ventral margin. Genotype : Hastifaba spinosa Cooper, n. sp. Hastifaba is distinguished from other Kloendenellidae by the prominence of the inflated and often spine-tipped pos- terodorsal portion of the carapace. Hastifaba spinosa Cooper, n. sp. Plate 18, figures 27-32 Carapace large, tumid; lateral outline semiovate; dorsal margin straight ante- riorly, arched posteriorly due to pro- jection of inflated valve above hinge line ; ventral margin straight, turning upward in broad curve anteriorty, poste- rior curve more abrupt ; overlap mod- erate around ends increasing along ven- ter, reaching maximum at posteroven- tral angle ; sulcus wide, deep, flaring at top to join low area just below hinge which outlines faint node anterior to sul- cus; posterior end greatly inflated, be- coming constricted dorsally into a short round spine that projects well above the hinge line ; a small spine projects for- ward from the anterior margin just be- low its termination ; surface smooth. Length, 1.08 mm; height, 0.66 mm; width, 0.55 mm. Cohn zone, locality 96. Hastifaba pervulgata Cooper, n. sp. Plate 18, figures 33-37 Carapace convex, dorsal margin sinu- ous, ends rounded ; ventral margin regu- larly convex, except for slightly flatten- ed portion near center which results from thickened border of right valve, in- creasing the apparent overlap at that point ; overlap uniform around re- mainder of free margins ; sulcus slightly anterior to center, quite deep in lower half, becoming shallower upward ; hinge line straight, bordered posteriorly by the sharp curved edges of the posterior in- flations: surface smooth. 112 PENNSYLVANIAN OSTRACODES Length, 0.97 mm; height, 0.64 mm; width, 0.43 mm. Similar to H. robusta, but lacks the thickened ventral edge of the left valve. Jamestown zone, locality 52. Hastifaba robusta Cooper, n. sp. Plate 18, figures 22-26 Carapace large, tumid ; dorsal margin sinuous ; ventral margin irregular due to development of a shelf or lip-like thick- ened rim of valve near midportion, pro- ducing a V-shaped channel in ventral view; ends rounded; sulcus U-shaped in cross-section, slightly forward of cen- ter, deeply incised, inclined toward an- terior ; posterior portion of shell greatly inflated, rising above straight hinge line, forming the sinuous dorsal margin in lateral view ; upper edge of inflated por- tion produced into a narrow ridge, most sharply defined along midportion of the hinge; line of articulation around free margins bordered by narrow rim, very short, slender spine on each valve just below midpoint of anterior portion of this rim ; surface smooth. Length, 1.05 mm; height, 0.64 mm; width, 0.53 mm. Summum zone, locality 28. Genus Jonesina Ulrich and Bassler, 1908 Jonesina biformis Bradfield Plate 18, figures 20, 21 Jonesina biformis Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 40, pi. 2, figs. 9a, b; 11a, b; Deese group, Oklahoma. Carapace semiovate in lateral outline ; hinge line short, straight ; ventral mar- gin slightly convex; ends rounded, the anterior more convex and higher than posterior; sulcus wide, shallow; overlap wide and uniform around anterior and ventral margins, narrower around poste- rior margin. Length, 0.77 mm ; height, 0.48 mm ; width, 0.30 mm. Seville zone, locality 6. Jonesina bradyana (Jones) Plate 18, figures 12, 13 Beyrichia bradyana Jones, 1886, Geol. Mag., n. ser., dec. 3, vol. 3, p. 438, pi. 12, figs. 11a, b; Carboniferous limestone, Great Britain. — Ulrich and Bassler, 1908, U. S. Nat. Mus. Proc, vol. 35, pi. 44, figs. 15, 16; Upper Glenn group, Oklahoma. — Harlton, 1927, Jour. Paleontology, vol. 1, p. 205, figs. 7a, b; Upper Glenn, Okla- homa. Sansabella bradyana Latham, 1933, Roy. Soc. Edinburgh Trans., vol. 57, pt. 2, no. 12, p. 367, fig. 13; Carboniferous, Scotland. Carapace ovate in lateral outline; hinge line straight; ends rounded, the anterior being narrower ; ventral margin concave ; sulcus posterior to middle, fair- ly wide, shallow, extends down from dorsum one-half shell height; overlap moderate, uniform around free margins ; short spine in anterior cardinal angle, very close to hinge line, but some dis- tance in from anterior margin. Length, 0.67 mm; height, 0.41 mm; width, 0.34 mm. Exline zone, locality 65. Jonesina deesensis Bradfield Plate 18, figures 16, 17 Jonesina deesensis Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 42, pi. 2, figs. 14a, b; Deese group, Oklahoma. Carapace ovate in outline; hinge line straight; ends subequally rounded; ven- tral margin almost straight, subparallel to hinge ; sulcus narrow, shallow, and nearly central ; overlap very narrow, uniform. Length, 0.68 mm ; height, 0.38 mm ; width, 0.36 mm. Gimlet zone, locality 62. Jonesina dubia Bradfield Plate 18, figures 10, 11 Jonesina dubia Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 43, pi. 3, figs, la, b; Deese group, Oklahoma. Carapace very short, somewhat tumid ; semiovate in lateral outline; hinge line short, straight; ventral margin convex; ends almost equally rounded ; sulcus KLOEDENELLIDAE 113 fairly narrow, deep, and elongate, ex- tending somewhat below midheight ; overlap narrow, uniform around free margins. Length, 0.47 mm; height, 0.32 mm; width, 0.25 mm. Though slightly smaller than the holo- type, the Illinois specimens agree in other respects. The straight posterior margin of Bradfield's figure is a result of crushing. Brereton zone, locality 37. JONESINA ELONGATA Cooper, n. Sp. Plate 18, figures 18, 19 Carapace elongate, semiquadrilateral in outline, hinge line straight except posterior quarter which is somewhat downcurved; ventral margin straight, subparallel to hinge line; ends rounded, anterior more convex than posterior; sulcus slightly posterior, elongate, nar- row and fairly deep ; overlap narrow. Length, 0.57 mm; height, 0.27 mm; width 0.25 mm. Bogota zone, locality 103. Jonesina infrequens (Bradfield) Plate 18, figures 6, 7 Nuferella infrequens Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 46, pi. 3, figs. 4a, b; Hoxbar group, Oklahoma. Carapace semiovate in lateral outline ; hinge line long, straight, without over- lap or incisement; ventral margin strongly convex; ends rounded, poste- rior end higher ; sulcus elongate, narrow, and deep ; spine small, short, high in anterodorsal angle; overlap moderate, and fairly uniform. Length, 0.42 mm; height, 0.28 mm; width, 0.21 mm. The quite low anterior end of the holo- type, giving an accentuated ''backward swing ' ' is due to crushing. The hollinel- lid node of the original description is in no way different from the usual dorso- lateral sculpture of Jonesina. The artic- ulation of the hinge is also typical of the latter. "Centralia" zone, locality 80. Jonesina subquadrata? Delo Plate 18, figures 14, 15 Jonesina suoquadrata Delo, 1930, Jour. Paleontology, vol. 4, p. 161, pi. 12, figs. 11a, b; Pennsylvanian, Texas. Not Jonesina suoquadrata, Upson, 1933, Ne- braska Geol. Survey Bull. 8, p. 47, pi. 3, fig. 5a. — Kummerow, 1939, Preuss. geol. Landesanstalt, Abh., n.f., no. 194, pt. A, p. 23, pi. 2, figs. 12a-c. Carapace ovate in lateral outline; hinge line straight, fairly short; ends subequally rounded, posterior end some- what flattened ; ventral margin straight, parallel to hinge; overlap very narrow around free margins ; sulcus shallow, in- distinct. Length, 0.73 mm; height, 0.40 mm; width, 0.37 mm. Gimlet to Little Vermilion zones, lo- calities 59, 62, 65, 88, 100, 103. Jonesina trisulcata ? Bradfield Plate 18, figures 8, 9 Jonesina trisulcata Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 43, pi. 2, figs. 15; 16a, b; 17a, b; Deese group, Oklahoma. Carapace small, subrectangular in lat- eral outline ; hinge line convex ; ends rounded, posterior less convex than ante- rior; ventral margin slightly concave; sulcus central, fairly deep, somewhat narrow; overlap faint. Length, 0.55 mm ; height, 0.28 mm ; width, 0.24 mm. The two sulci of Bradfield's species are very faint or lacking on the Illinois specimens. However, the dorsal area near the hinge line is somewhat less in- flated than normal, especially in the an- terodorsal angle. Examination of the holotype shows these features to be over emphasized in Bradfield's figure 15. Exline zone, locality 65. 114 PENN8YLVANIAN 08TRAC0DES Genus Kloedenella Ulrich and Bassler, 1908 Kloedenella carbonica Cooper, n. sp. Plate 19, figures 20-22 Carapace large, flat, and very thin; lateral outline semiovate ; dorsal margin straight, ventral margin convex, ends rounded and unequal in height ; cardinal angles obtuse; overlap faint around ends, increasing slightly around ventral margin ; contact margins bordered by a very thin, narrow margin raised slightly above shell surface ; hinge straight, san- sabelloid, slightly incised posteriorly ; two sulci, one central the other anterior, are narrow, shallow, and vertical, cen- tral one shorter ; surface finely punctate. Length, 1.28 mm; height, 0.78 mm; width, 0.50 mm. This is the only known Pennsylvanian species of Kloedenella and is distinguish- ed by its very thin shell, faint sulci and very finely puncate surface. Cohn zone, locality 96. Genus Lochriella Scott, 1942 Lochriella ampla Cooper, n. sp. Plate 19, figures 12, 13 Carapace large, somewhat tumid; lateral outline semielliptical ; dorsal and centroventral margins straight, the lat- ter turning upward in a broad curve to meet rounded end margins ; ends of sub- equal height, posterior slightly higher; overlap uniformly wide around contact margins; hinge long, straight, incised posteriorly, and terminated at each end by a triangular notch overlapping from right valve ; sulcus well forward of mid- length ; elongate, deep, inclined anterior- ly, and flaring at top to join a fairly wide depressed area bordering the hinge ; surface very finely punctate. Length, 1.26 mm ; height, 0.64 mm ; width, 0.50 mm. L. ampla can be recognized by the subparallel dorsal and ventral margins, and the verypromient, inclined sulcus. Bogota zone, locality 106. Lochriella? angusta Cooper, n. sp. Plate 19, figures 18, 19 Carapace elongate, thin ; lateral out- line subelliptical ; dorsal margin straight, ventral margin broadly convex; ends subequally rounded, the posterior slight- ly narrower; forward ''swing" moder- ate; sulcus well forward of midlength; deep, of uniform width, inclined toward anterior; overlap narrow and uniform around contact margins; hinge line straight and incised only on posterior end. Length, 0.80 mm; height, 0.45 mm; width, 0.32 mm. L. angusta is recognized by its elon- gate form (ratio 1.78) and the straight, inclined sulcus. Exline zone, locality 65. Lochriella elongata Cooper, n. sp. Plate 19, figures 23, 24 Carapace fairly large, elongate ; later- al outline subelliptical; dorsal and cen- troventral margins straight; ends un- equally rounded but of equal height; posteroventral angle markedly truncate, resulting in a posterior termination well above midheight; hinge long, straight, and moderately incised posteriorly ; overlap of moderate width, uniform around contact margins; sulcus wide, deep, vertical, widening slightly ventral- ly, and joining depressed area near hinge without much flaring; surface very finely punctate. Length, 1.04 mm ; height, 0.54 mm ; width, 0.29 mm. L. elongata is easily recognized by its elongate form (ratio 1.92) and truncate posteroventral margin. Cohn and Bogota zones, localities 95, 106. Genus Sansabella Roundy, 1926 Sansabella amplectans Roundy Plate 19, figures 10, 11 Sansabella amjilectans Roundy, 1926, U. S. Geol. Survey Prof. Paper 146, p. 6, pi. 1, figs. 3a-5; Marble Falls formation, Texas. KLOEDENELLIDAE 115 Carapace semiovate in lateral view; fairly tumid; dorsal margin straight, ventral margin convex; ends unequally rounded, with distinct retral ' ' swing ' ' ; hinge line straight, incised, and notched at each end; overlap prominent around free margins, especially along the poste- rior two-thirds of venter; greatest height and width posterior; small por- tion of a frill showing on posteroven- tral angle, emerging at line of articula- tion ; sulcus wide and shallow ; pit short, well back from margins ; surface smooth. Length, 0.74 mm ; height, 0. 46 mm ; width, 0.36 mm. Liverpool zone, locality 16. Sansabella bolliaformis (Ulrich and Bassler) Plate 19, figures 14-17 Beyrichiella bolliaformis Ulrich and Bassler, 1906, U. S. Nat. Mus. Proc, vol. 30, p. 158, pi. 11, fig. 7, 8; Cottonwood forma- tion, Kansas. Beyrichiella bolliaformis tumida Ulrich and Bassler, 1906, idem, p. 158, pi. 11, figs. 9-11; Cottonwood formation, Kansas. Jonesina bolliaformis, Ulrich and Bassler, 1908, idem, vol. 35, pi. 44, figs. 3-5. — Kel- lett, 1933, Jour. Paleontology, vol. 7, p. 78, pi. 14, figs. 1-8, 17-19, 32-36; Cotton- wood formation, Kansas. Jonesina bolliaformis tumida, Ulrich and Bassler, 1908, U. S. Nat. Mus. Proc, vol. 35, pi. 44, figs. 3-5. Jonesina subquadrata, Delo, 1933, Nebraska Geol. Survey Bull. 8, p. 47, pi. 3, fig. 5a; Cottonwood limestone, Nebraska. Coryella stovalli Harris and Lalicker, 1933, Nebraska Geol. Survey Bull. 8, p. 50, pi. 3, figs. 2a-c; Wreford limestone, Ne- braska. Carapace small, somewhat flat; dor- sal margin slightly convex, nearly flat; ventral margin strongly convex; ends rounded and of unequal height ; hinge straight, channeled, typically sansabel- loid; overlap moderate around ends, be- coming wider along ventral margin ; two nodes just below dorsal margin, on either side of a wide shallow sulcus, are joined ventralty by a low distinct ridge which is marked by a rather abrupt ven - tral margin ; remnants of a very tenuous frill at line of juncture of valves present on some well-preserved specimens. Length, 0.74 mm; height, 0.41 mm; width, 0.32 mm. The species belongs to Sansabella be- cause of the typically channeled (men- tioned in the original description) hinge- ment, which feature definitely excludes it from Jonesina. The Bollia-like sur- face sculpture serves to distinguish it from other species of Sansabella. "Centralia" zone, locality 82. Sansabella brevis Cooper, n. sp. Plate 19, figures 25, 26 Carapace short, tumid ; lateral outline subcircular to subovate ; dorsal margin flatly convex ; ventral margin convex, merging into uniformly rounded ends of equal height ; hinge line short, incis- ed; overlap very wide along ventral margin, decreasing rapidly and becom- ing very narrow at cardinal angles ; sul- cus broad, deep, and of uniform width. Length, 0.62 mm ; height, 0.50 mm ; width, 0.41 mm. This species is recognized by its short, high lateral outline (form ratio 1.12). Little Vermilion zone, locality 103. Sansabella carbonaria Cooper, n. sp. Plate 19, figures 30-35 Carapace small, tumid ; lateral outline semielliptical ; dorsal margin straight ; ventral margin strongly convex, merg- ing smoothly into ends of about equal height but subequally curved, resulting in a distinct forward ' ' swing ' ' ; overlap prominent, widest along centroventral margin, decreasing gradually to cardinal angles; hinge line straight, relatively short and incised ; sulcus pit-like ; deep- est near lower end, becoming shallow up- ward, in some specimens almost disap- pearing and resembling a pit instead of a sulcus. Length, 0.81 mm ; height, 0.52 mm ; width, 0.41 mm. 116 PENNSYLVANIAN 0STRAC0DE8 8. carbonaria has a less angulated lat- eral outline than 8. whitei Bradfield and lacks the posterodorsal node of 8. trun- cal -a- Cooper (1941, pi. 13, figs. 36-41). Trivoli to LaSalle zones, localities 70, 72, 81, 88. Sansabella exilis Cooper, n. sp. Plate 19, figures 27-29 Carapace small, tumid, elongate to slender, lateral outline semi-elliptical ; dorsal margin nearly straight ; ven- tral margin broadly convex; ends un- equally rounded, posterior quite narrow or almost acuminate, terminating un- usually high above midheight; overlap wide, prominent especially along centro- ventral margin ; anteroventral angle sharp ; surface smooth. Length, 0.82 mm; height, 0.46 mm; width, 0.41 mm. 8. exilis is recognized by its elongate lateral outline (form ratio 1.78), the narrow posterior end and sharply curv- ed anteroventral angle. Liverpool zone, locality 16. Sansabella laevis (Warthin) Plate 19, figures 1-9 Kirkbyina laevis Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 62, pi. 4, figs. 12a, b; Wewoka formation, Oklahoma. ?— Coryell and Sample, 1932, Am. Mid- land Naturalist, vol. 13, p. 256, pi. 24, fig. 11; East Mountain shale, Texas. — Brad- field, 1935, Bull. Am. Paleontology, vol. 22, p. 45, pi. 3, figs. 3a, b; Hoxbar forma- tion, Oklahoma. Sansabella laevis, Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 11, pi. 5, figs. 11-15; Chanute and Plattsburg forma- tions, Nebraska. Carapace small, tumid to thin ; lateral outline ovate ; dorsal margin slightly convex ; ventral margin strongly convex ; ends unequally rounded, resulting in a distinct forward ' ' swing ' ' ; anterior termination below midheight, posterior above ; hinge line straight and incised, with larger overlapping valve slightly higher than smaller ; in females greatest length central, greatest thickness poste- rior; surface smooth. Female (figs. 4-6) : Length, 0.82 mm; height, 0.54 mm ; width, 0.43 mm. Male (figs. 1-3; 7-9): Length, 0.84 mm. height, 0.51 mm ; width, 0.32 mm. Liverpool zone, localities 16, 20. Sansabella ovale Cooper, n. sp. Plate 20, figures 42, 43 Carapace small, flat; lateral outline ovate ; dorsal margin slightly convex ; ventral margin strongly convex, curv- ing smoothly into subequally rounded end margins; posterior end narrow and terminated above midheight; forward "swing" prominent; overlap moderate near cardinal angles, increasing to very broad in centroventral margin, widest just below sulcus ; sulcus deep, fairly wide hour-glass shaped ; anterior end flat accentuating the anterior node. Length, 0.78 mm ; height, 0. 51 mm ; width, 0.35 mm. 8. ovale is recognized by the variable overlap, the hour-glass shaped sulcus and the prominence of the anterior node. Trivoli to Little Vermilion zones, lo- calities 72, 86, 103. Sansabella sulcata? Roundy Plate 20, figures 37-39 Sansabella sulcata Roundy, 1936, U. S. Geol. Survey Prof. Paper 146, p. 6, pi. 1, figs. 6a-7; Barnett shale, Texas. Carapace fairly large, tumid; lateral outline semiovate ; ends unequally rounded, posterior higher; dorsal and centroventral margins straight ; hinge line long, straight, and incised; overlap wide, uniform around contact margins; sulcus deep, narrow in lower part, flar- ing rapidly above into a depressed area bordering the anterodorsal margin ; pos- terior end greatly inflated; posteroven- tral margin nearly straight. Length, 0.97 mm; height, 0.56 mm; width, 0.40 mm. This species corresponds to 8. sulcata in the shape of the lateral outline, the LEPERDITELLIDAE 117 character of overlap, and position of sul- cus. However, the sulcus is more promi- nent and the posterior end is more tu- mid, which differences could readily be due to the greater inflation of female specimens. Exline zone, locality 65. Sansabella whitei Bradfield Plate 20, figures 35, 36 Sansabella whitei Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 44, pi. 3, figs. 2a, b; Hoxbar group, Oklahoma. Carapace small, tumid ; lateral outline semiovate; ends unequally rounded, an- terior being" much narrower ; dorsal mar- gin nearly straight; ventral margin broadly convex; hinge line straight, in- cised, and-terminated by a notch at each end; sulcus shallow, anterior; greatest height immediately below sulcus; great- est length dorsal due to the high position of posterior termination ; overlap promi- nent around contact margins, with a small portion of frill showing in antero- dorsal angle, greatest thickness poste- rior. Length, 0.76 mm; height, 0.48 mm; width, 0.38 mm. Summum to Macoupin zones, localities 26, 51, 62, 86. Genus Sargentina Coryell and Johnson, 1939 Sargentina was classified under the Cytherellidae by Coryell and Johnson (1939, p. 223) and Cooper (1941, pp. 38, 39) but further study shows that it probably belongs in the Kloedenellidae because of its prominently sulcate form which allies it closely with Sansabella, Lochriella, and Jonesina. Sargentina elongata Cooper, n. sp. Plate 20, figures 40, 41 Carapace small, moderately tumid; lateral outline subovate, dorsal and ven- tral margins subequally convex; ends rounded, of about equal height, but ter- minating on opposite sides of midheight, giving a distinct forward " swing"; overlap relatively narrow around con- tact margin, greatest centroventrally ; sulcus very wide, shallow sides merging gradually with the curvature of shell; projection of larger shell above hinge line moderate; hinge straight and in- cised. Length, 0.83 mm ; height, 0.50 mm ; width, 0.41 mm. S. elongata is recognized by its long form ratio (1.68) and by the broad shal- low sulcus, as contrasted to the deep narrow sulci with abrupt margins of other described species. Little Vermilion zone, locality 103. Sargentina tumida Cooper, n. sp. Plate 20, figures 21-23 Carapace small, short, tumid; lateral outline ovate ; dorsal and ventral margins subequally convex ; ends round- ed and of about equal height, but ter- minating below and above midheight, giving the lateral outline a pronounced forward ' ' swing ' ' ; sulcus long, shallow, narrowing upward to a mere line ; over- lap variable, greatest along ventral and posterior margins ; right valve rises con- siderably above left along hinge line, especially in the central portion; hinge straight. Length, 0.62 mm; height, 0.40 mm; width, 0.32 mm. S. tumida is smaller, more elongate, and has a narrower sulcus than previ- ously described Chester species. "Centralia" zone, locality 80. Family Leperditellidae Ulrich and Bassler, 1906 Genus Cyathus Roth and Skinner, 1930 Cyathus striatus Cooper, n. sp. Plate 20, figures 5-8 Carapace small, elongate, semiellipti- cal ; valves equal ; dorsal margin straight, ventral margin convex ; lenticular in dorsal outline ; ends rounded, anterior less regular than posterior; hinge 118 PENNSYLVANIAN OSTRACODES straight, slightly incised in a fairly wide, shallow, V-shaped groove, notched at each end of left valve much as in San- sabella; ventral margin infolded to line of commissure, forming a broad, shal- low U-shaped channel along venter; greatest height central, greatest thick- ness just back of midlength; surface completely covered, even in shallow dor- sal and ventral channels, with extremely fine striations subparallel to the mar- gins; subcircular muscle spot just below and slightly anterior to center discern- able on well-preserved specimens. Length, 0.48 mm ; height, 0.30 mm ; width, 0.28 mm. C. striatus seems sufficiently distinct- ive, particularly in dorsal outline and character of channels, to be a new species, although it comes from beds comparable to those which produced the genotj^pe C. ulrichi Roth and Skinner. Seville zone, localities 5, 6. Genus Microparaparchites Croneis and Gale, 1939 Microparaparchites angustiis Cooper, n. sp. Plate 20, figure 12 Carapace small, very short ; dorsal outline short, straight ; lateral outline tear-drop shaped ; spine very short, wide at base, protruded downward to form indistinct shoulder; forward swing pro- nounced. Length, 0.51 mm ; height, 0.45 mm. M. angustiis has the lowest form ratio (1.14) of any described species of Micro- paraparchites. Summum zone, locality 26. Microparaparchites brazoensis (Coryell and Sample) Plate 20, figures 16-18 Paraparchites brazoensis Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 249, pi. 24, fig. 5; East Mountain shale, Texas. — Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 32, pi. 1, fig. 8; Deese group, Oklahoma. Paraparchites latidorsalis Warthin, 1930, Oklahoma Geol. Survey Bull. 53, p. 55, pi. 4, figs, la, b; Wewoka formation, Oklahoma. Paraparchites oblongus, Coryell and Sample, 1932 (not Jones and Kirkby), Am. Mid- land Naturalist, vol. 13, p. 250, pi. 24, fig. 3; East Mountain shale, Texas. Paraparchites imlopintoensis Coryell and Sample, 1932, idem, p. 248, pi. 24, fig. 4; East Mountain shale, Texas. Carapace small, rather tumid, subovate in lateral outline, ventral margin convex; dorsal margin slightly bowed in center; hinge line straight and somewhat incised in posterior half ; posterodorsal portions of both valves produced into propor- tionally large thick spines directed out- ward and upward from shell surface; overlap very faint around free margins. Length, 0.63 mm ; height, 0. 46 mm ; width, 0.35. Sparland to Exline zones, localities 56, 59, 62, 66. .Microparaparchites cornutus Cooper, n. sp. Plate 20, figures 13-15 Carapace small, tumid, lateral outline semiovate ; dorsal margin convex poste- riorly and concave anteriorly ; hinge line fairly long, incised ; spines very long, tapered, flaring at base, and directed sharply upward and laterally, overlap very faint. Length, 0.54 mm; height, 0.38 mm; width, 0.32 mm. M. cornutus is differentiated by its un- usually long, heavy spines and by the irregular dorsal outline. Liverpool zone, locality 18. Microparaparchites cuneatus (Warthin) Plate 20, figures 1, 2 Paraparchites cuneatus Warthin, 1930, Okla- homa Geol. Survey Bull. 53, p. 56, pi. 4, figs. 2a, b; Holdenville formation, Okla- homa. Paraparchites thomasi Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13. p. 248, pi. 24, fig. 1; East Mountain shale, Texas. LEPERDITELLIDAE 111) Carapace very small, lateral outline semiovate ; anterior end broadly curved, posterior much more narrow; spines very large and directed outward and upward; overlap inconspicuous. Length, 0.29 mm; height, 0.188 mm; width, 0.13 mm. The unusually small size of this spe- cies raises the question as to whether or not this is a young moult of M. hrazoen- sis Coryell and Sample (1932, p. 249) which occurs in correlative beds in Texas, Oklahoma and Illinois. However, this cannot be determined until the en- tire moult series has been studied. Gimlet zone, locality 59. MlCROPARAPARCHITES ELONGATUS Cooper, n. sp. Plate 20, figures 9-11 Carapace small, elongate, lateral out- line subelliptical ; ventral margin strong- ly convex ; ends unequally rounded, for- ward "swing" pronounced; hinge line relatively long, incised; spines short, widely flaring at base; overlap narrow around free margins. Length, 0.61 mm; height, 0.36 mm; width, 0.30 mm. M. elongatus is easily recognized by its unusually large form ratio (1.70). Liverpool to Sparland zones, localities 17, 20, 37, 56. MlCROPARAPARCHITES OVATUS Cooper, n. sp. Plate 20, figures 3, 4 Carapace small, relatively short, later- al outline, semiovate; dorsal margin slightly arched in center; ventral mar- gin and ends broadly curved, almost hemispherical; forward "swing" very slight; hinge line of moderate length, straight, and incised for most of its length ; spines very short, widely flaring at base to join shell surface without in- terruption of regular curvature; overlap very faint. Length, 0.40 mm; height, 0.34 mm; width, 0.23 mm. M. ovatus is distinguished by its short form ratio, small spines, and nearly semicircular lateral outline. Liverpool to St. David zones, locali- ties 16, 18, 22, 26, 30. MlCROPARAPARCHITES QUADRATUS Cooper, n. sp. Plate 20, figures 19, 20 Paraparchites latidorsatus, Coryell and Sample, 1932 (not Warthin), Am. Mid- land Naturalist, vol. 13, p. 249, pi. 24, fig. 2; East Mountain shale, Texas. Carapace small, somewhat tumid ; ends subequally rounded; dorsal margin straight ; spines short, thick, directed more upward than laterally ; overlap in- conspicuous; hinge line straight and in- cised. Length, 0.57 mm ; height, 0.35 mm ; width, 0.29 mm. Brereton zone, locality 37. MlCROPARAPARCHITES WAPANUCKAENSIS (Harlton) Plate 20, figures 24-26 Paraparchites wapanuckaensis Harlton, 1928, Jour. Paleontology, vol. 2, p. 132, pi. 21, figs, la, b; Wapanucka limestone, Okla- homa. — Harlton, 1929, Am. Jour. Sci., ser. 5, vol. 18, p. 255, pi. 1, figs. 3a, b; Wapanucka limestone, Oklahoma. — Harlton, 1933, Jour. Paleontology, vol. 7, p. 19, pi. 6, figs, la, b; Johns Valley shale, Oklahoma. — B 1 adfield, 1935, Bull. Am. Paleontology, vol. 22, p. 28, pi. 1, fig. 1; Dornick Hills group, Oklahoma. ParaparcTiites ottervillicus Bradfield, 1935, idem, p. 30, pi. 1, fig. 2, Dornick Hills group, Oklahoma. Carapace small, asymmetrical, some- what tumid; dorsal margin short, straight, with posterior half of hinge line deeply incised ; anterior end broadly curved, posterior quite narrow; spines rather large, broad at base, posterior edge extending downward as a promi- nent ridge or shoulder almost to the margin of shell ; overlap indistinct. Length, 0.55 mm ; height, 0.40 mm ; width, 0.26 mm. Wiley to Sparland zones, localities 13, 14, 18, 20, 30, 31, 55. 120 PENN8YLVANIAN OSTRACODES Genus Paraparchites Ulrich and Bassler, 1906 Paraparchites claytonensis Knight Plate 20, figures 27-34 Paraparchites claytonensis Knight, 1928, Jour. Paleontology, vol. 2, p. 231, pi. 31, figs. 8a-d; Pawnee limestone, Missouri. Carapace large, semiovate in lateral out- line, hinge line relatively short, straight, ends subequally rounded ; ventral mar- gin convex; a short, slender spine pro- jects upward from anterodorsal angle, well in back of the hinge termination; surface smooth. Length (figs. 27-30), 1.75 mm; height, 1.30 mm; width, 0.80 mm. Seville zone, locality 4. Paraparchites dispar Cooper, n. sp. Plate 21, figures 35, 36 Carapace small, rather flat; lateral outline semiovate ; hinge line long, straight ; posterior end straight dorsally, gradually merging below into broad curve around the posteroventral and ventral margins resulting in a very high posterior end; anterior end rounded; overlap narrow around free margins. Length, 0.64 mm; height, 0.45 mm; width, 0.37 mm. In many respects P. dispar resembles P. acutus (Jones and Kirkby), particu- larly the form shown by Kummerow (1939, pi. 1, fig. 3). However, the latter has a distinctly more rounded posterior end and greater overlap. Gimlet zone, locality 62. Paraparchites exiguus Cooper, n. sp. Plate 21, figures 22-27 Carapace small, tumid ; lateral outline semiovate ; dorsal margin convex in cen- ter; ventral margin and ends broadly convex ; anterior end quite narrow ; over- lap around free margins narrow ; dorsal overlap reversed and accentuated by the convexity of the dorsal margin of left valve; surface smooth. Length (figs. 25-27), 0.46 mm; height, 0.34 mm ; width, 0.27 mm. P. exiguus because of its extremely small size may be an immature moult of an undetermined species. It somewhat resembles the smallest specimen of P. humerosus Ulrich and Bassler figured by Kellett (1933, pi. 7, figs. 7, 12). Seville and Gimlet zones, localities 5, 62. Paraparchites fabula Cooper, n. sp. Plate 21, figures 28-30 Carapace small, tumid, lateral outline ovate ; dorsal margin straight ; ends and ventral margins convex; hinge line short, straight ; overlap very narrow. Length, 0.34 mm; height, 0.22 mm; width, 0.20 mm. P. fabula closely resembles P. exiguus n. sp. but lacks the convex dorsal margin of the latter. Gimlet zone, locality 62. Paraparchites inornatus? (McCoy) Plate 21, figure 39 See Bassler and Kellett (1934, p. 426) and Cooper (1941, p. 62) for synonmy. This crushed specimen possesses the typical outline of the species with its distinct retral swing and unequal height of anterior and posterior ends. Of specimens listed from the Pennsylvanian it has a longer hinge line than that figur- ed by Harlton (1927, p. 203) from the Cisco series of Texas, and a more pro- nounced retral " swing" than the Delo's form from Hamilton County, Kansas. Possibly these differ from those of the Chester, in which series they are very widely distributed. Length, 1.25 mm; height, 0.80 mm. Trivoli zone, locality 68. Paraparchites semicircularis Cooper, n. sp. Plate 21, figurse 31-34 Carapace medium sized, short, tumid; lateral outline subcircular; hinge line YOUNGIELLIDAE 121 very short, straight ; ends equally round- ed; ventral margin strongly convex; spine very small, short, and near dorsal margin, well back from anterior margin ; surface smooth. Length, 1.30 mm; height, 1.0 mm; width, 0.69 mm. This species resembles P. claytonensis Knight, except for its very small length (form ratio, 1.3) and differs from P. humerosus Ulrich and Bassler and P. inornatus (McCoy) in the lack of a retral "swing". It also bears some re- semblance to P. discoideus Kummerow (1939, p. 12). Seville zone, locality 4. Genus Paraparchitella Cooper, n. gen. Carapace ovate in lateral outline, dor- sal and ventral margins strongly convex, ends rounded; dorsal and ventral over- laps reversed, left valve overlapping right nearly to one-third its height ven- trally ; dorsal overlap narrow, right over left; hinge line short, shallowly de- pressed. Genotype : Paraparchitella o v at a Cooper, n. sp. Paraparchitella differs from Parapar- chites by its highly arched dorsum and from this and other Leperditellidae by its extreme ventral overlap. Paraparchitella ovata Cooper, n. sp. Plate 21, figures 40-43 Carapace small, tumid ; lateral outline ovate; dorsal and ventral margins sub- equally convex, the latter slightly trun- cate posteriorly; ends unequally round- ed, anterior quite narrow in lateral and dorsal views; dorsal overlap short, nar- row ; ventral overlap reversed, extending around ventral margin and one-third the distance up the left valve ; hinge short and incised in a short, shallow, lens- shaped depression ; greatest height and thickness posterior; surface smooth. Length, 0.65 mm; height, 0.41 mm; width, 0.33 mm. Seville zone, locality 6. Genus Proparaparchites Cooper, 1941 Proparaparchites parallelus Cooper, n. sp. Plate 21, figures 37, 38 Carapace small, thin; lateral outline subrectangular ; dorsal and ventral mar- gins straight; ends subequally rounded, with very faint backward "swing"; hinge line straight; cardinal angles ob- tuse; surface smooth; shell walls very thin. Length, 0.55 mm; height, 0.35 mm; width, 0.18 mm. This may be distinguished from the Chester species by its parallel dorsal and ventral margins and the very thin shell walls. Gimlet zone, locality 62. Family Youngiellidae Kellett, 1933 19 Genus Moo-rites Coryell and Billings, 1932 The genotype species M. hewetti has been shown by Kellett (1933, p. 104) to be a synonym of M. minutus (Warthin) and since then a nmber of additional oc- currences of this species have been noted. Other described species, which also probably should be placed in syno- nomy with M. minutus, have appeared in the literature. There is considerable variation in the dimensions of the specimens which have been referred to M. minutus. Plotting their length and height results in an ag- gregation of points which cannot be re- solved into a moult series. The form ratios vary from 1.68 to 2.30, which to- gether with the scattered positions of the plotted points, indicates the presence of more than one species. Until a number of moult studies can be made from topo- type collections, it will not be possible to clear up this matter. The genotype is probably an immature moult of M. minutus, as it has the same form ratio but is considerably smaller. 19 In a previous report (Cooper, 1941, p. 64) this family was erroneously credited to Jones and Kirkby. 122 PENN8YLVANIAN OSTRACODES Many species originally described as Youngiella have been transferred to this genus because they do not possess the transverse teeth along the hinge line of the genotype species, Y. rectidorsalis Jones and Kirkby. The hinge of Moor- it es is cardine (Cooper, 1941, p. 38). Moorites elongatus? (Jones and Kirkby) Plate 21, figures 7-10 Cytherella? elongata Jones and Kirkby, 18S6, Annals and Mag. Natural History, ser. 5, vol. 18, p. 262, pi. 9, figs. 2, 3; Lower limestone, Scotland. fMoorea elongata Coryell and Sample, 1932, Am. Midland Naturalist, vol. 13, p. 258, pi. 25, fig. 19; East Mountain shale, Texas. Youngiella? elongata, Bassler and Kellett, 1934, Geol. Soc. Am. Spec. Papers 1, p. 494. Not Youngiella? elongata, Bradfield, 1935, Bull. Am. Paleontology, vol. 22, p. 72, pi. 4, fig. 14. Youngiella? gracilis Bradfield, 1935, idem, p. 73, pi. 4, figs. 15a, b; Deese group, Okla- homa. Moorites elongatus, Cooper, 1941 Illinois Geol. Survey Report, Invest. 77, p. 64, pi. 14, figs. 20, 21; Paint Creek forma- tion, Illinois. Length (figs. 7, 8), 0.38 mm; height, 0.19 mm ; width, 0.13 mm. These small unornamented forms are probably small moults belonging to a larger, undetermined species, and the Chester forms cannot be differentiated from those from the Pennsylvanian. Moorites elongata (Bradfield) is a homo- nym, and probably an imperfectly pre- served specimen of M. minutus (War- thin). Brereton to Shumway zones, localities 37, 59, 62, 70, 83, 103, 109. Moorites indentus Cooper, n. sp. Plate 21, figures 1, 2 Carapace small, elongate; lateral out- line semiovate ; dorsal and ventral mar- gins straight, parallel; ends subequally rounded; backward ''swing" moderate; marginal ridge very wide, low, and bor- dering end margins only ; surface smooth, with a very shallow circular pit located in center of shell. Length, 0.39 mm; height, 0.20 mm; width, 0.15 mm. M. indentus is recognized by the small indistinct circular central pit. Exline to Newton zones, localities 66, 82, 112. Moorites knighti? (Wilson) Plate 21, figures 5, 6 Youngiella knighti Wilson, 1933, Jour. Pale- ontology, vol. 7, p. 417, pi. 50, figs. 2a-c; McAlester shale, Oklahoma. Carapace small, elongate ; lateral out- line semiovate, dorsal and ventral mar- gins straight, parallel; ends subequally rounded; backward swing fairly promi- nent ; marginal ridges absent or very faint around ends; surface smooth. Length, 0.35 mm ; height, 0.18 mm ; width, 0.13 mm. The small size and featureless surface of this species indicates that it is proba- bly an immature moult, possibly of M. wapanuckensis (Harlton). Seville to Newton zones, localities 4, 26, 29, 30, 66, 79, 82, 83, 112. Moorites minutus (Warthin) Plate 21, figures 11-17 Glyptopleurina? minuta Warthin, 1930, Okla- homa Geol. Survey Bull. 53, p. 67, pi. 5, figs. 6a, b; Holdenville formation. Moorites minutus, Coryell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 183, pi. 18, fig. 6; Wayland shale, Texas. — Coryell and Sample, 1932, idem, p. 256, pi. 24 fig, 18; East Mountain shale, Texas. — Kellett, 1933, Jour. Paleontology vol. 7, p. 104, pi. 14, figs. 37-39; Stanton to Howard formations. Kansas. — Brad- field, 1935, Bull. Am. Paleontology, vol. 22, p. 73, pi. 5, figs, la, b; Deese and Hoxbar groups, Oklahoma. ■ — Johnson, 1936, Nebraska Geol. Survey Paper 11, p. 37, pi. 3, figs. 20, 21; Stanton and Plattsburg formations, Nebraska. Youngiella minutus, Wilson, 1933, Jour. Paleontology, vol. 7, p. 416, pi. 50, fig. 7; McAlester shale, Oklahoma. Youngiella? convergens Bradfie'.d, 1935, Bull. Am. Paleontology, vol. 22, p. 72, pi. 4, figs. 16a, b; Deese group, Oklahoma. YOUNGIELLIDAE 123 Youngiella? elongata, Bradfield. 1935, idem, p. 72, pi. 4, fig. 14; Deese group, Okla- homa. Moorites Keivetti Coryell and Billings, 1932, Am. Midland Naturalist, vol. 13, p. 182, pi. 18, fig. 5; Wayland shale, Texas. —Coryell and Sample, 1932, idem, p. 257, pi. 24, fig. 17; East Mountain shale, Texas. Moorites truncatus Coryell and Billings, 1932, idem, p. 183, pi. 18, fig. 7; Wayland shale, Texas. Carapace very small, elongate; dorsal margin long, straight; hinge line incis- ed ; ventral margin concave ; anterior end almost straight, posterior end rounded; backward "swing" pronounc- ed, resulting in an obtuse anteriodorsal angle and an acute angle posteriorly; the wide end prominent marginal ridge is especially noticeable in dorsal view; surface puncate, with low, inosculating ridges separating rows or groups of punctae. Length, 0.42 mm; height, 0.24 mm; width, 0.16 mm. This species, common throughout the entire Pennsylvanian section, is recog- nized by the prominent rounded ridge that borders the free margins and the pattern of costae or other small inflated portions that separate the punctae. It resembles M. rhomboidalis (Croneis and Gale) but the backward swing is less pronounced in the Chester species. Seville to Woodbury zones, localities 4, 5, 11, 26, 30, 33, 34, 37, 38, 43, 46, 62, 63, 66, 69, 79, 81, 82, 83, 88, 103, 107, 108, 112, 115. Moorites functus (Wilson) Plate 21, figures 3, 4 Youngiella puncta Wilson, 1933, Jour. Pale- ontology, vol. 7, p. 416, pi. 50, figs. 4a-d; McAlester shale, Oklahoma. Carapace small, lateral outline subrec- tangular; dorsal and ventral margins straight; ends about equally rounded and bordered by fairly prominent wide ridge which dies out at the ventral mar- gin ; surface flat and marked by numer- ous small punctae. Length, 0.40 mm; height, 0.20 mm; width, 0.11 mm. M. punctus lacks the backward •'swing 7 ', and the ridge bordering the ventral margin of 31. minutus. Liverpool to Gimlet zones, localities 14, 16, 17, 62. Moorites spiciferus (Wilson) Plate 21, figures 20, 21 Youngiella spicifera Wilson, 1933, Jour. Paleontology, vol. 7, p. 417, pi. 50, fig. 8a (only); McAlester shale. Oklahoma. Carapace small, elongate, somewhat tumid; dorsal margin straight, ventral margin concave ; ends subequally round- ed, the posterior much higher ; ends bor- dered by marginal ridge which is lacking along venter; backward "swing" prom- inent ; surface coarsely punctate. Length, 0.46 mm; height, 0.21 mm; width, 0.17 mm. M. spiciferus may be recognized by its elongate form (ratio, 2.2) and the coarsely punctate surface. Seville and St. David zones, localities 6, 29. Moorites wapanuckensis (Harlton) Plate 21, figures 18,19 Youngiella ivapanuckensis Harlton, 1933, Jour. Paleontology, vol. 7, p. 25, pi. 7, figs. 3a, b; Johns Valley shale, Okla- homa. Carapace, small, short, thin ; dorsal and ventral margins straight ; posterior end rounded, anterior end nearly straight ; free margin bordered by a very wide smooth, prominent ridge ; surface inside ridge flat and marked by numer- ous pits. Length, 0.49 mm ; height, 0.26 mm ; width, 0.13 mm. M. wapanuckensis is recognized by the straight parallel dorsal and ventral mar- gins, its extreme thinness and the very prominent marginal ridge. Seville to Collinsville zones, localities 4, 63, 73. REFERENCES Baird, W., 1850, Natural History of the Brit- ish Entomostraca: The Ray Society, London. Bassler, R. S. and Kellett, Betty, 1934, Bibliographic index of Paleozoic Os- tracoda: Geol. Soc. America, Special Paper 1. Blake, C. H., 1930, The ostracode genus Hollinella: Jour. Paleontology, vol. 4, no. 3, pp. 297-298. Bradfield, H. H., 1935, Pennsylvanian Ostra- coda of the Ardmore basin, Oklahoma: Bull. Am. Paleontology, vol. 22, no. 73, pis. 1-13. Brady, G. S. and Norman, A. M., 1870, Mono- graph of the marine and freshwater Ostracoda of the North Atlantic and northwestern Europe; I, Podocopa: Royal Soc. Dublin Trans., ser. 2, vol. 4, pp. 61-270. Brady, H. B., ms. in, Jones, T. R., 1886, On some fringed and other Ostracoda from the Carboniferous series: Geol. 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New York Acad. Sci., vol. 20, no. 3, pt. 2, pp. 232. Hamilton, Irving B., 1942, Ostracodes from the Upper Permain of Texas: Jour. Paleontology, vol. 16, pp. 712-718, pi. 110. Harlton, B. H., 1927, Some Pennsylvanian Ostracoda of the Glenn and Hoxbar formations of southern Oklahoma and the Upper part of the Cisco formation of northern Texas: Jour. Paleontol- ogy, vol. 1, pp. 203-212, pis. 32-33. , 1928, Pennsylvanian Foraminifera of Oklahoma and Texas: idem, vol. 1, pp. 306-310, pis. 52-53. , 1928, Pennsylvanian ostracodes from Oklahoma and Texas: idem, vol. 2, pp. 132-141, pi. 21. , 1929, Pennsylvanian Ostracoda from Menard County, Texas: Texas Univ. Bull. 2901, pp. 139-161, pis. 1-4. 124 REFERENCES 125 , 1929, Some Upper Mississippian (Fayetteville) and Lower Pennsyl- vanian (Wapanucka-Morrow) Ostra- coda of Oklahoma and Arkansas: Am. Jour. Sci., ser. 5, vol. 18, no. 105, pp. 254-270, pis. 1, 2. , 1929, Some Pennsylvanian Ostracoda from southern Oklahoma — a correc- tion: Jour. Paleontology, vol. 3, no. 3, p. 308. , 1931, New names for species of Bairdia: idem, vol. 5, no. 2, p. 163. , 1933, Micropaleontology of the Penn- sylvanian Johns Valley shale of the Ouachita Mountains, Oklahoma, and its relationship to the Mississippian Caney shale: idem, vol. 7, pp. 3-29, pis. 1-7. HxVbris, R. W. and Lalicker, Cecil G., 1932, New Upper Carboniferous Ostracoda from Oklahoma and Kansas: Am. Mid- land Naturalist, vol. 13, pp. 396-409, pis. 36, 37. Holland, W. C, 1934, Ostracodes of the Nineveh limestone of Pennsylvania and West Virginia: Carnegie Mus. Ann., vol. 22, pp. 343-350, pi. 25. Johnson, W. R., 1936, The Ostracoda of the Missouri Series in Nebraska: Ne- braska Geol. Survey Paper 11, pp. 1-52, pis. 1-5. Jones, T. Rupert, 1862, A monograph of the fossil Estheriae; supplement: Paleon- tographical Soc. Mon., pp. 120-128, pi. 5, figs. 13-34. , 1884, Notes on the late Mr. George Tate's specimens of Lower Carboni- ferous Entomostraca from Berwick- shire and Northumberland: Berwick- shire Nat. Club, Proc, vol. 10, pp. 312-326, pi. 2. , 1886, On some fringed and other Os- tracoda from the Carboniferous series: Geol. Mag., n.s., dec. 3, vol. 3, pp. 433-439, pis. 11, 12, London. Jones, T. R. and Holl, H. B., 1869, Notes on the Paleozoic bivalved Entomostraca, no. 9. Some Silurian species: Annals and Mag. Nat. History, ser. 4, vol. 3, pp. 211-227, pis. 14, 15. Jones, T. R., and Kirkby, J. W., 1860, On Permian Entomostraca from the shell- limestone of Durham, by J. W. Kirkby, with notes on the species by T. Rupert Jones: Tyneside Nat. Field Club. Trans, vol. 4, (1858-1860) pp. 122-171, pis. 8-11. . 1867, On the Entomostraca of the Carboniferous rocks of Scotland: Geol. Soc. Glasgow Trans., vol. 2, pp. 213-228. , 1879, Notes on the Paleozoic bivalved Entomostraca, no. 12. Some Carboni- ferous species belonging to the genus Carbonia Jones: Annals and Mag. Nat. History, ser. 5, vol. 4, pp. 28-39, pis. 2, 3. , 1879, Description of the species of the ostracodous genus Bairdia McCoy from the Carboniferous strata of Great Britain: Geol. Soc. London Quart. Jour., vol. 35, pp. 565-581, pis. 28-32. , 1886, Notes on the Paleozoic bivalved Entomostraca, no. 22, Annals and Mag. Nat. History, ser. 5, vol. 18, pp. 249-269, pis. 6-9. , 1890, On the Ostracoda found in the shales of the Upper Coal Measures at Slade Lane, near Manchester: Man- chester Geol. Soc. Trans., vol. 21, pt. 3, pp. 137-142, pi. 1. , 1892, Notes on the Paleozoic bivalved Entomostraca, no. 30. On Carboni- ferous Ostracoda from Mongolia: An- nals and Mag. Nat. History, ser. 6, vol. 9, pp. 302-307, pi. 16. Kellett, Betty, 1929, The ostracode genus Hollinella, expansion of the genus and description of some Carboniferous species: Jour. Paleontology, vol. 3, pp. 196-217, pis. 25, 26. , 1933, Ostracodes of the Upper Penn- sylvanian and the Lower Permian strata of Kansas, 1: the Aparchitidae, Beyrichiidae, Glytopleuridae, Kloede- nellidae, Kirkbyidae, and Youngielli- dae: idem, vol. 7, pp. 59-108, pis. 13-16. , 1934, Ostracodes from the Upper Pennsylvanian and Lower Permian strata of Kansas, 2; the genus Bair- dia: idem, vol. 8, pp. 120-138, pis. 14-19. , 1935, Ostracodes of the Upper Penn- sylvanian and Lower Permian strata of Kansas, 3; Bairdiidae (concl.), Cytherellidae, Cypridinidae, Entomo- conchidae, Cytheridae, and Cypridae: idem, vol. 9, pp. 132-166. , 1936, Carboniferous Ostracodes: idem, vol. 10, no. 8, pp. 769-784. Kirkby, J. W., 1858, On Permian Entomos- traca from the fossiliferous limestone of Durham: Annals and Mae:. Nat. History, ser. 3, vol. 2, pp. 317-330, 432- 439, pi. 10. , 1861, On the Permian rocks of South Yorkshire and their paleontological relations: Geol. Soc. London Quart. Jour., vol. 17, p. 308. , 1862, On some additional species that are common in the Carboniferous and Permian strata: Annals and Mag. Nat. History, sec. 3, vol. 10, pp. 202- 205, pi. 4, figs. 1-12. Knight, J. B., 1928, Some Pennsylvanian ostracodes from the Henrietta forma- tion of eastern Missouri: Jour. Palen- tology, vol. 2, pp. 229-267, pis. 30-34; pp. 318-336, pis. 43, 44. Kummerow, E. H. E., 1939, Die Ostracoden und Phyllopoden des deutschen Unter- carbons: Preuss. Geol. Landesanstalt. Abh., neue folge. no. 194, pp. 1-107, pis. 1-7, pt. A, Ostracoda. 126 PENNSYLVANIAN OSTRA CODES Lalicker, C. G., 1935, Cavellina nebrascensis (Geinitz): Jour. Paleontology, vol. 9, no. 8, pp. 744-745, 7 figs. Latham, Mary A., 1933, Scottish Carboni- ferous Ostracoda: Roy. Soc. Edin- burgh Trans., 57, pt. 2, no. 12, 1932- 1933. (Issued separately Oct. 27, 1932) pp. 351-395, 25 text figs. Moore, R. C, 1929, Basslerina, a new hollini- form ostracode genus, with descrip- tion of new Pennsylvanian species from Texas and Oklahoma: Denison Univ. Bull. Jour. Sci. Lab., vol. 24, pp. 99-113, pis. 6-8. , et al, 1944, Correlation of the Penn- sylvanian formations of North Ameri- ca: Geol. Soc. America Bull., vol. 55, pp. 657-706, chart. Newton, William A., 1941, Surface struc- ture map of Shelby, Effingham, and Fayette counties: Illinois Geol. Sur- vey Rept. Invest. 76. Payne, Kenneth A., 1937, Pennsylvanian Ostracoda from Sullivan County, Indi- ana: Jour. Paleontology, vol. 11, pp. 276-288, pis. 38-40. Pruvost, Pierre, 1911, Notes sur les Ento- mostraca bivalves du terrain Houiller de Nord de la France. Soc. Geol. Nord Ann., vol. 40, pp. 68-80, pi. 2. Reuss, A. E., 1854, Ueber Entomostraceen und Foraminiferen in Zechstein der Wettereau: Jahresber. Wetterauer Gesell. Gesamm. Naturk, Hanau, 1851- 53, pp. 59-77, pi., Hanau. Richter, Reinhard, 1867, Aus dem thiir- ingischen Zechstein: Deutsch. Geol. Ges., Zeitschr., vol. 19, pp. 219-236, pi. 5. Roth, Robert, 1928, Monoceratina, a new genus of Ostracoda from the Pennsyl- vanian of Oklahoma: Jour. Paleontol- ogy, vol. 2, pp. 15-19, figs. 1, 2. , 1929, A comparative faunal chart of the Mississippian and Morrow forma- tions of Oklahoma and Arkansas; Oklahoma Geol. Survey, circ. 18, chart. -, 1929, A revision of the ostracode genus Kirkbya and subgenus Amphis- sites: Wagner Free Inst. Sci., publ. 1, pp. 1-55, pis. 1-3. Roth, Robert and Skinner, John, 1930, The fauna of the McCoy formation, Penn- sylvanian, of Colorado: Jour. Paleon- tology, vol. 4, pp. 332-352, pi. 28. Roundy, P. V., 1926, Mississippian forma- tions of San Saba County, Texas: U. S. Geol. Survey, Prof. Paper 146, pp. 5-8, pi. 1. Roundy, P. V., in Moore, R. C, 1926, Fossils from wells in central Kansas: Kansas Geol. Survey, Bull. 10, pt. 3, p. 103. Schmidt, E. E., 1867, Die kleineren organi- schen Formen des Zechsteinkalkes von Selters in der Wetterau: Neues Jahrb. Min., Geol., Paleon., Jahrg, 1867, pp. 577-582, pi. 6, figs. 1-45. Scott, Harold W., 1944, Permian and Penn- sylvanian fresh-water ostracodes: Jour. Paleontology, vol. 18, pp. 141-147, pis. 23, 24. , 1944, Muscle scar patterns on some upper Paleozoic ostracodes; idem, vol. 18, pp. 162-171, 28 figs. Scott, H. W. and Borger, H. D., 1941, Penn- sylvanian ostracodes from Lawrence County, Illinois: Idem, vol. 15, pp. 354-358, pis. 49, 50. Scott, Harold W. and Summerson, Charles H., 1943, Nonmarine Ostracoda from the Lower Pennsylvanian in the south- ern Appalachians and their bearing on inter-continental correlations: Am. Jour. Sci., vol. 241, pp. 653-675, pis. 1,2. Swartz, F. M., 1936, Revision of the Primitii- dae and Beyrichiidae with new Ostra- coda from the lower Devonian of Pennsylvania: Jour. Paleontology, vol. 10, no. 7, pp. 541-586, pis. 78-89. Ulbich, E. O., 1891, New and little known American Paleozoic Ostracoda: Cin- cinnati Soc. Nat. Hist. Jour., vol. 13, pp. 104-137, 1890; pp. 173-211, pi. 18. Ulbich, E. O. and Bassler, R. S., 1906, New American Paleozoic Ostracoda. Notes and descriptions of Upper Carbonifer- ous genera and species: U. S. Nat. Mus. Proc, vol. 30, pp. 149-164, pi. 11. , 1908, New American Paleozoic Ostra- coda. Preliminary revision of the Beyrichiidae, with descriptions of new genera: idem, vol. 35, pp. 277-340, figs. 1-61, pis. 37-44. Upson, M. E. 1933, The Ostracoda of the Big Blue series in Nebraska: Nebraska Geol. Survey Bull. 8, pp. 1-54, pis. 1-4. Wanless, H. R., 1931, Pennsylvanian cycles in western Illinois: Illinois Geol. Sur- vey Bull. 60, pp. 179-193. , 1939, Pennsylvanian correlations in the eastern Interior and Appalachian coal fields. Geol. Soc. America Spec. Papers 17. Warthin, A. S., Jr., 1930, Micropaleontology of the Wetumka, Wewoka, and Hold- enville formations: Oklahoma Geol. Survey Bull. 53, pis. 1-7. Weller, J. Marvin, 1930, Cyclical sedimen- tation in the Pennsylvanian and its significance: Jour. Geol., vol. 38, pp. 97-135. , 1931, The conception of cyclical sedi- mentation during the Pennsylvanian period: Illinois Geol. Survey Bull. 60, pp. 161-177. Weller, J. M., Wanless, H. R., Cline, L. M. and Stookey, D. G., 1942, Interbasin Pennsylvanian correlations, Illinois and Iowa: Am. Assoc. Petroleum Geol- ogists Bull., vol. 26, pp. 1585-1593. Wilmarth, M. Grace, 1938, Lexicon of geol- ogic names of the United States: U. S. Geol. Survey Bull. 896. Wilson, C. W. Jr., 1933, Fauna of the Mc- Alester shale, Pennsylvanian, of Mus- kokee County, Oklahoma: Jour. Pale* ontology, vol. 7, pp. 412-422, pi. 50, figs. 1-9. PLATES AND EXPLANATIONS Illinois State Geological Survey Bulletin 70, Plate 1 Explanation of Plate 1 Figures Page 1-6 Monoceratina bradfieldi Cooper, n. sp. Dorsal, end, lateral, and ventral views; 1, 2, paratype; 3-6, holotype; Little Vermilion zone, loc. 103, X 40 39 7-8 Ardmorea gibberosa (Knight). Lateral and dorsal views; Lonsdale zone, loc. 62, X 40 40 9 Monoceratina ardmorensis (Harlton). Lateral view; Fulda formation, loc. 1, X 40 39 10-12 Monoceratina lewisi Harris and Lalicker. Lateral and end views; Lonsdale zone, loc. 62, X 40 ■ 39 13 Monoceratina, macoupeni Scott and Borger. Lateral view; Gimlet zone, loc. 62, X 40 39 14-15 Bairdia ardmorensis Harlton. Lateral and dorsal views; Ferdinand lime- stone, loc. 2, X 20 41 16-19 Bairdia blakei Harlton. Lateral, dorsal, ventral, and end views; Shumway zone, loc. 109, X 30 42 20-22 Bairdia altifrons Knight. Lateral, dorsal, anterior, and end views; Lons- dale zone, loc. 62, X 20 40 23-26 Bairdia citriformis Knight. Dorsal, lateral, ventral, and end views; Brere- ton zone, loc. 45, X 30 43 27-28 Bairdia acuminata Cooper, n. sp. Lateral and dorsal views of holotype; Little Vermilion zone, loc. 103, X 30 40 29-30 Bairdia ciscoensis? Harlton. Lateral and dorsal views; Woodbury zone, loc. 115, X 40 42 31-34 Bairdia concava Cooper, n. sp. Dorsal, ventral, lateral, and end views of holotype; Greenup zone, loc. 114, X 20 43 35-40 Bairdia beedei Ulrich and Bassler. 35-38, Lateral, dorsal, ventral, and end views; Millersville limestone, loc. 90, X 20. 39-40, Lateral and dorsal views ; Brereton zone, loc. 46, X 20 41 41-44 Bairdia angusta Cooper, n. sp. Lateral, dorsal, and end views of holotype; Seville zone, loc. 4, X 20 41 45-49 Bairdia ampla Reuss. Dorsal, lateral, ventral, and end views; Shumway zone, loc. 109, X 20 40 1 129 Explanation of Plate 2 Figures Page 1-2 Bairdia crassa Harlton. Dorsal and lateral views; Brereton zone, loc. 40, X 20 44 3-5 Bairdia crassimarginata Cooper, n. sp. Dorsal, lateral, and ventral views of holotype ; LaSalle zone, loc. 88, X 20 44 6-7 Bairdia cf. B. glennensis Harlton. 6, Lateral view; Seahorne limestone, loc. 86. 7, Lateral view; Fulda formation, loc. 1, X 20 45 8-10 Bairdia coryelli Roth and Skinner. Dorsal, lateral, and end views; Arroyo formation, Texas, loc. 119, X 20 43 11-13 Bairdia hurwitzi Coryell and Booth. Dorsal, lateral, and ventral views; Newton zone, loc. 108, X 20 46 14-18 Bairdia garrisonensis Upson. Dorsal, lateral, ventral, and end views; Shumway zone, loc. 109, X 20 45 19-20 Bairdia lunata Bradfield. Dorsal and lateral views; Millersvillp limestone, loc. 90, X 20 47 21-22 Bairdia hooverae Kellett. Dorsal and lateral views; LaSalle zone, loc. 88, X 30 46 23-26 Bairdia demissa Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype ; Woodbury zone, loc. 115, X 30 44 27-29 Bairdia dissimilis Cooper, n. sp. Dorsal, lateral, and end views of holo- type ; Seville zone, loc. 8, X 30 44 30-31 Bairdia harltoni Cooper, n. sp. Dorsal and lateral views of holotype; Seville zone, loc. 8, X 20 45 32-35 Bairdia menardensis Harlton. Dorsal, lateral, ventral, and end views; Lonsdale zone, loc. 62, X 20 47 36-37 Bairdia kingii Reuss. Dorsal and lateral views; Newton zone, loc. 108, X 30 47 38-42 Bairdia menardvillensis Harlton. Dorsal, lateral, ventral, and end views; Lonsdale zone, loc. 62, X 20 48 43-44 Bairdia hoxbarensis Harlton. Dorsal and lateral views; Trivoli zone, loc. 68, X 30 46 [130] Illinois State Geological Survey Bulletin 70, Plate 2 Illinois State Geological Survey Bulletin 70, Plate 3 Explanation of Plate 3 Figures Page 1-4 Bairdia pennata Coryell and Sample. Lateral and dorsal views; 1-2, Liver- pool zone, loc. 22. 3-4, Liverpool zone, loc. 21, X 30 49 5-10 Bairdia monstrabilis Cooper, n. sp. 5-9, Dorsal, lateral, ventral, and end views of holotype; Omega zone, loc. 93, X 20. 10, Lateral view of para- type; Macoupin zone, loc. 84, X 20 48 11-12 Bairdia peracuta Warthin. Dorsal and lateral views; Lonsdale zone, loc. 60, X 20 49 13-14 Bairdia pinnula Coryell and Booth. Dorsal and lateral views; Shumway zone, loc. 109, X 30 49 15-20 Bairdia oklahomaensis Harlton. 15-19, Dorsal, lateral, ventral, and end views; Macoupin zone, loc. 86; 20, Lateral view, Liverpool zone, loc. 21, X 20 48 21-24 Bairdia schaurothiana Kirkby. Dorsal, lateral, ventral, and end views; Seville zone, loc. 8, X 20 50 25-26 Bairdia cf. jB. rhomboidea Kirkby. Dorsal and lateral views; Shumway zone, loc. 109, X 20 50 27-29 Bairdia seminalis Knight. Dorsal, lateral, and ventral views; Lonsdale zone, loc. 62, X 30 51 30-32 Bairdia regularis Cooper, n. sp. Dorsal, ventral, and lateral views of holo- type; Exline zone, loc. 66, X 20 50 33-34 Bairdia scholli Coryell and Booth. Lateral and dorsal views; Little Ver- milion zone, loc. 103, X 20 51 35-36 Bairdia summa Coryell and Billings. Dorsal and lateral views; "Centralia" zone, loc. 82, X 20 52 37-38 Bairdia symmetrica Cooper, n. sp. Dorsal and lateral views of holotype; Trivoli zone, loc. 69, X 30 52 39-43 Bairdia pompilioides Harlton. Dorsal, lateral, ventral, and end views; Millersville limestone, loc. 90, X 20 49 44-46 Bairdia spinosa Cooper, n. sp. Dorsal and lateral views of holotype; Shoal Creek zone, loc. 77, X 30 52 133] Explanation of Plate 4 Figures Page 1-2 Bairdia peracuta Warthin. Dorsal and lateral views; Liverpool zone, loc. 21, X 20 49 3-4 Bairdia pennata Coryell and Sample. Dorsal and lateral views; Ferdinand formation, loc. 2, X 20 49 5-6 Bairdia ciscoensisf Harlton. Dorsal and lateral views; Collinsville zone, loc. 73, X 40 42 7-8 Bairdia verwiebei Kellett. Dorsal and lateral views; Newton zone, loc. 112, X 30 52 9-11 Bairdia menardvillensis Harlton. Dorsal, lateral, and ventral views; Exline zone, loc. 66, X 20 48 12-15 Bairdia whitesidei Bradfield. Dorsal, lateral, and end views; Brereton zone, loc. 38, X 20 53 16-17 Bairdia coryelli Roth and Skinner. Dorsal and lateral views; Greenup zone, loc. 114, X 20 43 18-19 Bairdiacypris ardua Cooper, n. sp. Dorsal and lateral views of holotype; Shumway zone, loc. 109, X 20 53 20-21 Bairdiacypris haydenbranchensis (Payne). Dorsal and lateral views; Millersville zone, loc. 90, X 20 54 22-23 Bairdiacypris deloi Bradfield. Dorsal and lateral views; "Centralia" zone, loc. 82, X 20 53 24-25 Bairdiacypris acuminata Cooper, n. sp. Dorsal and lateral views of holo- type ; LaSalle zone, loc. 88, X 20 53 26-27 Bairdiacypris shideleri (Delo). Dorsal and ventral views; Lonsdale zone, loc. 62, X 20 54 28-29 Bairdiacypris nebraskensis (Upson). Dorsal and lateral views; Exline zone, loc. 66, X 20 54 30-31 Bythocypris subpediformis Bradfield. Dorsal and lateral views of holo- type; Little Vermilion zone, loc. 103, X 40 55 32-33 Bythocypris disparilis Cooper, n. sp. Dorsal and lateral views of holotype; "Centralia" zone, loc. 81, X 40 55 34-35 Bythocypris quadrata Cooper, n. sp. Dorsal and lateral views of holotype; "Centralia" zone, loc. 82, X 40 55 36-38 Bairdiacypris trojana (Wilson). Dorsal, lateral, and ventral views; Seville zone, loc. 7, X 20 . .' 54 39-40 Coryellites cooki (Bradfield). Dorsal and lateral views; Liverpool zone, loc. 19, X 40 56 41-42 Coryellites contracta Cooper, n. sp. Dorsal and lateral views of holotype; St. David zone, loc. 30, X 40 56 43-44 Coryellites elongata Cooper, n. sp. Dorsal and lateral views of holotype; Oak Grove beds, loc. 20, X 40 56 45-46 Coryellites centralis (Coryell and Billings). Dorsal and lateral views; Liverpool zone, loc. 19, X 40 56 [134] Illinois State Geological Survey Bulletin 70, Plate 4 Illinois State Geological Survey Bulletin 70, Plate 5 Explanation of Plate 5 Figuees Page 1-2 Coryellites mytilliformis (Bradfield). Dorsal and lateral views; Newton zone, loc. 112, X 40 , 57 3-4 Coryellites firma Kellett. Dorsal and lateral views; Liverpool zone, loc. 24, X 40 57 5-6 Coryellites johnsoni (Upson). Dorsal and lateral views; Exline zone, loc. 65, X 40 57 7-8 Coryellites ovata Cooper, n. sp. Dorsal and lateral views of holotype; Lons- dale zone, loc. 62, X 40 57 9-10 Coryellites palopintoensis (Coryell and Sample). Lateral and ventral views; Liverpool zone, loc. 19, X 40 58 11-14 Coryellites lowelli Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; Liverpool zone, loc. 22, X 40 57 15-16 Coryellites parallela (Knight). Dorsal and lateral views: Jamestown zone, loc. 51, X 40 58 17-18 Coryellites spotti Cooper, n. sp. Dorsal and lateral views of holotype; Woodbury zone, loc. 115, X 40 58 19-21 Coryellites pediformis (Knight). Dorsal, lateral, and end views; Seville zone, loc. 7, X 40 58 22-23 Coryellites tomlinsonella Cooper, n. sp. Dorsal and lateral views of holo- type ; Wiley zone, loc. 13, X 40 59 24-25 Coryellites simillima (Bradfield). Dorsal and lateral views; Liverpool zone, loc. 24, X 40 59 26 Faoalicypris plana Cooper, n. sp. Lateral view of holotype; Liverpool zone, loc. 16, X 30 60 27-28 Coryellites texensis (Coryell and Sample). Dorsal and lateral views; Macoupin zone, loc. 84, X 40 59 29-30 Coryellites suoelliptica (Upson). Dorsal and lateral views; Jamestown zone, loc. 52, X 40 59 31-32 Faoalicypris minuta Cooper, n. sp. Dorsal and lateral views of holotype; Seville zone, loc. 7, X 30 60 33-36 Faoalicypris acuminata Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; Liverpool zone, loc. 16, X 30 60 37-39 Faoalicypris dispar Cooper, n. sp. Dorsal, lateral, and ventral views of holotype; Liverpool zone, loc. 16, X 30 60 137 Explanation of Plate 6 Figures Page 1-3 Fabalicypris regularis Cooper, n. sp. Dorsal, lateral, and ventral views of holotype ; Seville zone, loc. 6, X 30 60 4-8 Fabalicypris wileyensis Cooper, n. gen. and n. sp. Dorsal, lateral, ventral, and end views of genoholotype; Wiley zone, loc. 13, X 30 61 9-11 Fabalicypris tenuis Cooper, n. sp. Dorsal, lateral, and ventral views of holotype; Seville limestone, loc. 3, X 30 61 12-19 Fabalicyj)ris ivetumkaensis Cooper, n. sp. Dorsal, lateral, ventral, and end views. 12-1 ~>, Seville zone, loc. 3; 16-19, holotype, Brereton zone, loc. 46, X 30 61 20-21 Microcheilinella inflata Kellett. Dorsal and lateral views; Bogota zone, loc. 97, X 40 63 22-24 Macrocypris illinoensis Scott and Borger. Dorsal, lateral, and end views; Greenup zone, loc. 114, X 40 62 25-27 Macrocypris bicurvata Cooper, n. sp. Dorsal, lateral, and end views of holotype; Greenup zone, loc. 114, X 40 61 28-30 Macrocypris teretis Cooper, n. sp. Lateral, dorsal, and end views of holo- type ; St. David zone, loc. 28, X 40 62 31-33 Microcheilinella unispinosa Cooper, n. sp. End, lateral, and dorsal views of holotype ; Little Vermilion zone, loc. 102, X 40 63 34-37 Microcheilinella bicornuta Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; "Centralia" zone, loc. 82, X 40 62 3S-40 Macrocypris lenticularis Cooper, n. sp. Dorsal, lateral, and ventral views of holotype ; Greenup zone, loc. 114, X 40 62 41-44 Microcheilinella quddrata Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; Brereton zone, loc. 45, X 30 63 45-46 Macrocypris menardensis Harlton. Dorsal and lateral views; Brereton zone, loc. 42, X 30 62 47-49 Microcheilinella minuta Cooper, n. sp. Dorsal, lateral, and end views of holotype; Seville zone, loc. 6, X 40 63 50-51 Macrocypris garrisonensis Upson. Dorsal and lateral views; Lonsdale zone, loc. 62, X 30 61 138 Illinois State Geological Survey Bulletin 70, Plate Illinois State Geological Survey Bulletin 70, Plate 7 Explanation of Plate 7 Figures Page 1-3 Waylandella vulgaris Cooper, n. sp. 1, 2, Dorsal and lateral views of holo- type; Seville formation, loc. 3. 3, Lateral view of interior of left valve of paratype; Wiley zone, loc. 13, X 40 65 4-6 Waylandella ardmorensis (Bradfield). Dorsal, lateral, and end views; Brereton zone, loc. 41, X 40 64 7-10 Waylandella cuyleri Coryell and Booth. Dorsal, lateral, ventral, and end views; Sparland zone, loc. 56 X 40 64 11-13 Waylandella regularis Cooper, n. sp. Dorsal, lateral, and end views of holotype; Liverpool zone, loc. 16, X 40 65 14-16 Waylandella bythocyproidea (Warthin). Dorsal, lateral, and end views; Seahorne zone, loc. 11, X 40 64 17-21 Waylandella symmetrica Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; Liverpool zone, loc. 22, X 40 65 22-26 Waylandella obesa Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype ; Summum zone, loc. 31, X 40 65 27-28 Waylandella, dispar Cooper, n. sp. Dorsal and lateral views of holotype; Liverpool zone, loc. 14, X 40 64 29-31 Cavellina angusta Cooper, n. sp. Dorsal, lateral, and end views of holo- type; Liverpool zone, loc. 16, X 40 70 32-33 Cavellina cummingsi Payne. Dorsal and lateral views; Exline zone, loc. 65, X 40 71 34-35 Cavellina cavellinoides (Bradfield). Dorsal and lateral views; Lonsdale zone, loc. 63, X 40 71 36-37 Cavellina bisecta Bradfield. Dorsal and lateral views; Liverpool zone, loc. 16, X 40 70 [141 Explanation of Plate 8 Figures Page 1-2 Carbonita agnes (Jones). Dorsal and lateral views; Lonsdale zone, loc. 62, X 40 66 3-10 Candona bairdioides (Jones and Kirkby). S-6, Lateral, dorsal, ventral, and end views; Shelbyville zone, loc. 104, X 20. 7-10 Lateral, dorsal, ven- tral and end views ; Colin zone, loc. 95, X 30 65 11-14 Candona planidorsata Cooper, n. sp. Ventral, lateral, and end views of holotype; Hanover zone, loc. 31, X 30 66 15-16 Gutschickia levin Cooper, n. sp. Dorsal and lateral views of holotype; Han- over zone, ioc. 31, X 30 68 17-20 Gutschickia ovata Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype ; Hanover zone, loc. 31, X 20 68 21-25 Candona salteriana Jones and Kirkby. Dorsal, lateral, and end views; Shumway zone, loc. 106, X 20 66 26-32 Gutschickia subangulata (Jones and Kirkby). 26-28, Dorsal, lateral, and ventral views; below Ninevah member, Green formation, loc. 120. 29-3.2, Dorsal, lateral, ventral, and end views; Newton zone, loc. Ill, X 20 69 33-35 Carbonita tenuis Cooper, n. sp. Dorsal, lateral, and ventral views of holo- type ; Colin zone, loc. 95, X 40 68 36-39 Gutschickia ninevehensis (Holland). Dorsal, lateral, ventral, and end views; Colin zone, loc. 95, X 20 68 40-42 Carbonita inflata (Jones and Kirkby). Dorsal, lateral, and ventral views; Greenup zone. loc. 102, X 40 66 43-45 Carbonita orbiculata Cooper, n. sp. Dorsal, lateral, and end views of holo- type ; Seville zone, loc. 6, X 30 68 46-48 Carbonita magna (Upson). Dorsal, lateral, and end views, Shelbyville zone, loc. 105, X 40 67 [142] Illinois State Geological Survey Bulletin 70, Plate 8 Illinois State Geological Survey Bulletin 70, Plate 9 Explanation of Plate 9 Figures Page 1-2 Basslerella firma Kellett. Dorsal and lateral views; Lonsdale zone, loc. 62, X 40 69 3-4 Basslerella lacrimosa Cooper, n. sp. Dorsal and lateral views of holotype; Newton zone, loc. 108, X 40 69 5-7 Basslerella obesa Kellett. Dorsal, lateral, and end views; Lonsdale zone, loc. 62, X 40 69 8-10 Basslerella acuminata Cooper, n. sp. Dorsal, lateral, and end views of holo- type; Lonsdale zone, loc. 62, X 40 69 11-13 Cavellina equalis? Coryell. Dorsal, lateral, and end views; Hanover zone, loc. 26, X 20 71 14-15 Basslerella? parallela Cooper, n. sp. Dorsal and lateral views of holotype; Lonsdale zone, loc. 62, X 40 70 16-18 Basslerella rostrata (Knight). Dorsal, lateral, and end views; Lonsdale zone, loc. 62, X 40 70 19-20 Basslerella ovata Cooper, n. sp. Dorsal and lateral views of holotype; Newton zone, loc. 108, X 40 70 21-27 Cavellina flttsi Kellett. Dorsal, lateral, ventral, and end views; 21-24, Liverpool zone, loc. 14, X 30. 25-27, Oak Grove formation, loc. 20, X 20 72 28-29 Cavellina daubeana (Bradfield). Dorsal and lateral views; Exline zone, loc. 65, X 30 71 30-32 Cavellina laevis (Bradfield). Dorsal, lateral, and end views; Newton zone, loc. 112, X 30 72 33-35 Cavellina expansa Bradfield. Dorsal, lateral, and end views; Lonsdale zone, loc. 63, X 30 72 36-37 Cavellina jejuna Coryell and Sample. Dorsal and lateral views; Exline zone, loc. 65 X 20 72 38-39 Cavellina lintris Coryell and Sample. Dorsal and lateral views; Gimlet zone, loc. 57, X 30 73 40 Cavellina lata Coryell. Lateral view; Liverpool zone, loc. 14, X 30 73 41-45 Cavellina lirata (Bradfield). Dorsal, lateral, ventral, and end views; New- ton zone, loc. 112, X 30 73 46-47 Cavellina footei (Coryell and Booth). Dorsal and lateral views; Macoupin zone, loc. 86, X 30 72 [145; Explanation of Plate 10 Figures Page 1-4 Cavellina nebrascensis (Geinitz). Dorsal, lateral, ventral, and end views; Newton zone, loc. 112, X 20 73 5-6 Cavellina minuta Bradlield. Dorsal and lateral views; Exline zone, loc. 65, X 40 73 7-8 Cavellina ovidiformis (Harlton). Dorsal and lateral views; Little Ver- milion zone, loc. 103, X 20 74 9-18 Cavellina pulchella Coryell. Dorsal, lateral, ventral, and end views; 9-11, Macoupin zone, loc. 86; J 2-16, Jamestown zone, loc. 51. 17-18, Jamestown zone, loc. 51, X 20 74 19-22 Cavellina rotunda Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; Lonsdale zone, loc. 62, X 30 74 23-24 Cavellina subpnlchella Coryell. Dorsal and lateral views; Little Vermilion zone, loc. 103, X 30 74 25-26 Cavellina symmetrica (Payne). Dorsal and lateral views; Newton zone, loc. 112, X 30 75 27-28 Cavellina tongiaf (Coryell and Sample). Lateral and dorsal views; Col- linsville zone, loc. 73, X 30 75 29 Silenites asymmetrica Cooper, n. sp. Lateral view of holotoype; Seville zone, loc. 4, X 20 75 30-32 Silenites fabalis Cooper, n. sp. 30, Lateral view; St. David zone, loc. 33; 31-32, Lateral and dorsal views of holotype; Liverpool zone, loc. 23, X 20 76 33-36 Silenites lenticularis (Knight). Dorsal and lateral views; 33-34, St. David zone, loc. 35; 35-36 Brereton zone, loc. 47, X 20 76 37-38 Silenites silenus Coryell and Booth. Dorsal and lateral views; Newton zone, loc. 108, X^30 76 39-40 Darwinula pungens (Jones and Kirkby). Dorsal and lateral views; Han- over zone, loc. 31, X 40 78 41-42 Glytopleura irregularis Delo. Dorsal and lateral views; Millersville lime- stone, loc. 90, X 30 79 43-45 Glytopleura coryelli Harlton. Lateral, dorsal, and end views; Millersville limestone, loc. 90, X 30 79 [146] Illinois State Geological Survey Bulletin 70, Plate 10 Illinois State Geological Survey Bulletin 70, Plate 11 Explanation of Plate 11 Figures Page 1-15 Sulcella sulcata Coryell and Sample. Dorsal, ventral, lateral, and end views; 1-J t , Liverpool zone, loc. 14; 5-9, Shumway zone, loc. 107; 10-15, lateral views, showing size and shape variations; 10, 11, 15, Liverpool zone, loc. 16; 12, Seville zone, loc. 6; IS, Summum zone, loc. 26; 14, Lonsdale zone, loc. 62 76 16-23 Cornigella tuberculospinosa (Jones and Kirkby). Dorsal, lateral, and end views; 16-20, Exline zone, loc. 66; 21-23, Lonsdale zone, loc. 62, X 50.. 78 24-25 Healdia alba Coryell and Billings. Dorsal and lateral views; Livingston zone, loc. 92, X 40 79 26-28 Healdia Mcornis Cooper, n. sp. Dorsal, lateral, and end views of holotype; Trivoli zone, loc. 71, X 40 80 29-31 Healdia boggyensis Harlton. Dorsal, lateral, and end views; Seville zone, loc. 4, X 40 80 32-34 Healdia cincta Coryell and Billings. Dorsal and lateral views; Gimlet zone, loc. 58, X 40 81 35-36 Healdia carinata Cooper, n. sp. Dorsal and lateral views of holotype; Livingston zone, loc. 92, X 40 81 37-38 Healdia cava Bradfield. Dorsal and lateral views; Exline zone, loc. 66, X 40 81 39-40 Healdia aspinosa Cooper, n. sp. Dorsal and lateral views of holotype; Newton zone, loc. 112, X 40 80 41-42 Healdia asper Cooper, n. sp. Dorsal and lateral views of holotype; St. David zone, loc. 30, X 40 80 43-47 Healdia colonyi Coryell and Booth. 42-44, Dorsal, lateral, and end views; 45-46, inside views showing lines of articulation; Trivoli zone, loc. 69, X 40 81 48-49 Healdia carter ensis Bradfield. Dorsal and lateral views; St. David zone, loc. 29, X 40 81 149 Explanation of Plate 12 Figures Page 1-2 Healdia glennensis Harlton. Dorsal and lateral views; Seville zone, loc. 3, X 40 83 3-5 Healdia fabalis Cooper, n. sp. Dorsal, lateral, and end views of holotype; Seville zone, loc. 7, X 40 82 6-8 Healdia ehlersi Bradfield. Dorsal, lateral, and end views; Macoupin zone, loc. 84, X 40 82 9-10 Healdia formosa Harlton. Dorsal and lateral views; Brouillet zone, loc. 64, X 40 83 11-13 Healdia spinosa Cooper, n. sp. Dorsal, lateral, and end views of holotype; Hanover zone, loc. 26, X 40 86 14-16 Healdia coryelli Kellett. Dorsal, lateral, and end views; Newton zone loc, 112, X 40 82 17-18 Healdia limacoidea Knight. Dorsal and lateral views; Hanover zone, loc. 26, X 40 83 19-21 Healdia elegens Warthin. Dorsal, lateral, and end views; Brereton zone, loc. 41, X 40 82 22-24 Healdia longula Cooper, n. sp. Dorsal, lateral, and end views of holotype; Seville zone, loc. 3, X 40 84 25-26 Healdia masoni Coryell and Booth. Dorsal and lateral views; Little Ver- milion zone, loc. 103, X 50 84 27-31 Healdia granosa Cooper, n. sp. 27-20. Dorsal, lateral, and end views of holo- type; Liverpool zone, loc. 21. 80-81, Lateral views showing interior, lines of articulation, and muscle scars 83 32-33 Healdia cf. H. obsolens Delo. Dorsal and lateral views; LaSalle zone, loc. 88, X 40 85 34-35 Healdia oklahomaensis Harlton. Dorsal and lateral views; Jamestown zone, loc. 51, X 40 85 36-38 Healdia rectis Cooper, n. sp. Dorsal, lateral, and end views of holotype; Hanover zone, loc. 31, X 40 85 39-41 Healdia marginata Harlton. Dorsal, lateral, and end views; Liverpool zone, loc. 15, X 40 84 42-45 Healdia nucleolata Knight. Dorsal, lateral, and end views; Liverpool zone, loc. 14, X 40 84 46-48 Healdia oblonga Bradfield. Dorsal, lateral, and end views; Liverpool zone, loc. 16, X 40 85 [150] Illinois State Geological Survey Bulletin 70, Plate 12 Illinois State Geological Survey Bulletin 70, Plate 13 Explanation of Plate 13 Figures Page 1-2 Healdia simplex Roundy. Dorsal and lateral views; Livingston zone, loc. 92, X 40 86 3-7 Seminolites truncatus Coryell. Dorsal, lateral, ventral, and end views; Bogota zone, loc. 101, X 40 87 8-9 Healdia usitata Cooper, n. sp. Dorsal and lateral views of holotype; Gimlet zone, loc. 58, X 40 86 10-13 Healdiacypris acuminatus Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype; Oak Grove beds, loc. 15, X 40 86 14-16 Seminolites elongatus Coryell. Dorsal, lateral, and end views; Shumway zone, loc. 109, X 40 87 17-20 Healdiacypris perplexa Bradfield. Dorsal, lateral, ventral, and end views; Hanover zone, loc. 28, X 40 87 • 21-24 Hollinella emaciata (Ulrich and Bassler). Dorsal, lateral, ventral, and end views; Newton zone, loc. 112, X 20 91 25-27 Hollinella crassimarginata Kellett. 25-26, Dorsal and lateral views of adult; 27, Immature instar; Little Vermilion zone, loc. 103, X 20 89 28-29 Hollinella elongata Cooper, n. sp. Dorsal and lateral views of holotype; Brereton zone, loc. 37, X 20 91 30 Hollinella grahamensis Harlton. Lateral view, left valve of immature in- star; Bogota zone, loc. 100, X 20 91 31 Hollinella giooosa Kellett. Lateral view, left valve; Newton zone, loc. 112, X 20 91 32-38 Hollinella dentata Coryell. 32-33, Immature instars; 3> h narrow-frilled form; 35-36, interior views showing articulation; 37-38, adult right and left lateral wide-frilled carapaces; Summum zone, loc. 26, X 20 90 39 Hollinella burlingamensis Kellett. Lateral view, left valve; Greenup zone, loc. 113, X 20 89 40 Hollinella cushmani Kellett. Lateral view, left valve; Carlinville zone, loc. 78, X 20 90 41-46 Hollinella grandis Cooper, n. sp. 'tl-'i'i, Dorsal, lateral, ventral, and end views of holotype; Ji5-.'i6, interior view showing articulation; Macoupin zone, loc. 86, X 20 92 [153] Explanation of Plate 14 Figures Page 1 Hollinella levis Cooper, n. sp. Lateral view of right valve of holotype; Lonsdale zone, loc. 62, X 20 93 2-5 Hollinella radlerae (Harlton). Dorsal, lateral, ventral, and end views; LaSalle zone, loc. 88, X 20 95 6-10 Hollinella kellettae Knight. 6, Lateral view, adult right valve, St. David formation, loc. 31; 9-10, Immature instars; Liverpool zone. loc. 15, X 20 92 11-12 Hollinella minuta Cooper, n. sp. Lateral views, right valves: 11, Liverpool zone, loc. 15. 12, holotype, Liverpool zone, 14, X 20 94 13-14 Hollinella moorei Cooper, n. sp. 13, Lateral view of right valve, paratype. 14, Lateral view, left valve holotype; Newton zone, loc. 47, X 20 94 15 Hollinella pulchra (Moore). Lateral view, right valve; Brereton zone, loc. 47, X 20 95 16-17 ''Hollinella ulrichi" (Knight). (See H. Kellettae). Lateral views of right and left valves of wide- and narrow-frilled topotype; Wreford forma- tion, Riley Co., Kansas, loc. 116, X 20 92 18 Hollinella shaivnensis Kellett. Lateral view, left valve; Newton zone, loc. 112, X 20 96 19 Hollinella noivataensis Coryell and Osorio. Lateral view of left valve; Gimlet zone, loc. 58, X 20 ' 94 20-26 Hollinella regularis Coryell. 20, Immature instar; 21-22, Dorsal and lateral views of adult wide-frilled form, LaSalle zone, loc. 88, X 20; 23-26, Dor- sal, lateral, ventral, and end views of narrow-frilled form; Exline zone, loc. 67, X 20 96 27-30 Hollinella ivarthini Cooper, n. sp. Dorsal, lateral, ventral, and end views of holotype ; Exline zone, loc. 66, X 20 96 31-36 Hollinella limata (Moore). 31-34, Dorsal, lateral, ventral, and end views; 35-36, immature instars; Exline zone, loc. 66, X 20 93 37-45 Hollinella oklahomaensis? (Harlton). 37-39, Dorsal, left valve, and end views of form with wide, incurved frill; Exline formation, loc. 66. 40-41, Immature moults; ^.2-^5, Dorsal, lateral, ventral, and end views of form with a narrow, flared frill; Exline zone, loc. 67, X 20 94 154 Illinois State Geological Survey Bulletin 70, Plate 14 Illinois State Geological Survey Bulletin 70, Plate 15 Explanation of Plate 15 Figures Page 1-2 Amphissites transversus Roth. Dorsal and lateral views; Seahorne zone, loc. 9, X 30 100 3-6 Amphissites parvus Cooper, n. sp. Dorsal and lateral views; 3-4, holotype, Oak Grove beds, loc. 14; 5-6, paratype, Seville zone, loc. 3, X 40 99 7-8 Amphissites roundyi Knight. Dorsal and lateral views; St. David zone, loc. 29, X 30 100 9-11 Amphissites alticostatus Bradfield. 9-10, Dorsal and lateral views of adult; 11, Immature instar; Liverpool zone, loc. 16, X 30 97 12-14 Amphissites girtyi Knight. Dorsal, lateral, and end views; St. David zone, loc. 29, X 30 99 15-18 Amphissites carinatus Cooper, n. sp. Dorsal and lateral views; 15-16, holo- 21-22 type, Woodbury zone, loc. 115; 11-18, paratype, Bogota zone, loc. 101; 21-22, Greenup zone, loc. 114, X 30 97 19-20 Amphissites centronotus (Ulrich and Bassler). Dorsal and lateral views; LaSalle zone, loc. 88, X 30 98 23-25 Amphissites centronotus elongatus Payne. Dorsal, ventral, and end views; Bogota zone, loc. 97, X 30 98 26-28 Amphissites rothi Bradfield. Dorsal, lateral, and end views; LaSalle zone, loc. 88, X 30 100 29-31 Amphissites adjunctio Cooper, n. sp. Dorsal, lateral, and end views of holo- type; Livingston zone, loc. 93, X 30 97 32-33 Ectodemites genae (Roth). Dorsal and lateral views; Millersville limestone, loc. 90, X 30 102 34-36 Amphissites robustus Cooper, n. sp. 34-35, Dorsal and lateral views of holo- type; Macoupin zone, loc. 85. 36, Lateral view, right valve; Lonsdale zone, loc. 60, X 30 99 37-42 Ectodemites plummeri Cooper, n. sp. 67-39, Dorsal, lateral, and end views of holotype, Marble Falls formation, Texas. 40-42, Dorsal and lateral views of adult and lateral view of immature instar; Ferdinand forma- tion, loc. 2, X 30 103 43 Amphissites congruens Cooper, n. sp. Lateral view of holotype; LaSalle zone, loc. 88, X 30 99 44 Ectodemites harltoni Cooper, n. sp. Lateral view, right valve of holotype; Seville zone, loc. 4, X 30 102 15' Explanation of Plate 16 Figures Page 1-2 Ectodenites dattonenesis (Harlton). Dorsal and lateral views; Macoupin zone, loc. 85, X 30 101 3-4 Discoidella linyulata Cooper, n. sp. Dorsal and lateral views of holotype; Macoupin zone, loc. 83, X 40 101 5-6 Discoidella perminutaf (Kellett). Dorsal and lateral views; Little Ver- milion zone, loc. 103, X 40 101 7-8 Discoidella convexaf Scott and Borger. Dorsal and lateral views; Lonsdale zone, loc. 62, X 40 101 9-10 Ectodemites sullivanensis (Payne). Dorsal and lateral views; Millersville limestone, loc. 90, X 30 103 11-14 Kellettina robustaf (Kellett). Dorsal view; Lonsdale zone, loc. 61, X 30.. 103 15-17 Ectodenites edsonae (Bradfield). Dorsal and lateral views; Woodbury zone, loc. 115, X 30 102 18-20 Kirkbya inornata Roth. Dorsal, lateral, and end views; Seville zone, loc. 4, X 30 105 21-22 Polytylites wapaunckensis (Harlton). 21, Left valve; Fulda formation, loc. 1, X 30. 22, Right valve; Wapauncka limestone, Okla. loc. 118 108 Note Tolypammina on anterior end of fig. 22. 23-26 Kellettina montosa (Knight). Dorsal, lateral, ventral, and end views; 23-25, St. David zone, loc. 23; 26, Lonsdale zone, loc. 62, X 30 103 27-30 Kirkbya bendensis Harlton. Dorsal, lateral, and end views; 28-30, Seville zone, loc. 3 ; 27, Fulda limestone, loc. 1, X 30 104 31-34 Kirkbya arcuata? Roth. Dorsal, lateral, ventral, and end views; Livingston zone, loc. 93, X 30. ~Note Tolypammina on posterior end 104 35 Kirkbya magna Roth. Lateral view, left valve; Seville zone, loc. 4, X 30. . 105 36-37 Kirkbya firma Kellett. Dorsal and lateral views; Greenup zone, loc. 113, X 30 104 38-42 Kirkbya kellettae Harlton. Dorsal, lateral, ventral, and end views; 38, Sea- horne zone, loc. 12, 39-'/2, Wapanucka formation, Oklahoma, loc. 118, X 30 105 [158] Illinois State Geological Survey Bulletin 70. Plate 16 Illinois State Geological Survey i 'i i.i btin to, Plate it Explanation of Plate 17 Figures Page 1-4 Kirkbya cf. K. reflexa Girty. Lateral views; 1-2, Fulda limestone, loc. 1; 3-J h cotypes, of K. reflexa Girty, Fayetteville shale, Arkansas; X 30 106 5-8 Kirkbya puctata Kellett. Dorsal, lateral, ventral, and end views; Macoupin zone, loc. 84, X 30 106 9 Kirkbyella cf. K. gutkei Croneis and Bristol. Lateral view, left valve; Fulda limestone, loc. 1, X 40 106 10 Kirkbya pergrandis Kellett. Lateral view of left valve of a distorted and matrix-filled specimen; Lonsdale zone, loc. 63, X 20 106 11 Knightina ampla Kellett. Lateral view, right valve; Little Vermilion zone, loc. 103, X 30 107 12 Knightina allerismoides (Knight). Lateral view, right valve; Oak Grove beds, loc. 20, X 30 107 13 Knightina kellettae Bradfield. Lateral view right valve; Liverpool zone, loc. 22, X 30 108 14-16 Knightina harltoni Kellett. Dorsal, lateral and end views; Lexington forma- tion, loc. 117, X 30 107 17-18 Knightina hextensis (Harlton). Dorsal and lateral views; Gimlet zone, loc. 57, X 40 108 19-20 Ellipsella bradfieldi Cooper, n. sp. Dorsal and lateral views; Oak Grove beds, loc. 20, X 30 110 21-23 Geisina gallowayi (Bradfield). Dorsal, lateral, and end views; Jamestown zone, loc. 52, X 30 110 24-28 Ellipsella calcar (Harlton). Dorsal, lateral and end views; 24-26, male, Exline zone, loc. 66; 27-28, female, Bogota formation, loc. 100, X 40 109 29-36 Roundyella simplicissima (Knight). Dorsal, lateral, and end views. 29-31, Spinose form, Wiley zone, loc. 13; 32-33, "scoured" or smooth specimen showing few spines; Brereton zone, loc. 40. 3J/-36, Deeply reticulate and spinose form, and immature instar; Lonsdale formation, loc. 60, X 40. Note kirkbyan pit surrounded by reticuli in a roseate pat- tern in figs. 30 and 33 108 161 Explanation of Plate 18 Figures Page 1-2 Geisina QVegaria (Ulrich and Bassler). Lateral views; Jamestown zone loc. 52, X 30 -.. 3-4 Geisina jolliffina Cooper, n. sp. Lateral views; 4, holotype. Jamestown zone, loc. oZ, X 30 iia 5 Geisina warthini Cooper, n. sp. Lateral view, right valve of holotvne- Jamestown zone, loc. 52, X 30 ' p ' m 6-7 t/0??e ^« ioc r 80 tt6WS (BradfieldK Dorsal and lateral vi ews; "Centralia" 8-9 Jonesina trisulcatat Bradfield. Dorsal and lateral views; Exline zone, loc 65 ' X 40 '.... 113 10-11 Jonesina duoia Bradfield. Dorsal and lateral views; Brereton zone loc. 37, X 40 ' 112 12-13 Jonesina bradyana (Jones). Dorsal and lateral views; Exline zone loc 6o " x 30 '..... H2 14-15 Jonesina subquadrataf Delo. Dorsal and lateral views; LaSalle zone, IOC. oo, /\ 4U 11Q 16-17 Jonesina deesensis Bradfield. Dorsal and lateral views; Lonsdale zone loc. 62, X 30 ' 112 18-19 Jonesina elongata Cooper, n. sp. Dorsal and lateral views of holotvDe- Shumway zone, loc. 107, X 40 , ' 113 20-21 Jonesina biformis Bradfield. Dorsal and lateral views; Seville zone, loc. 6 ' x 30 .' 112 22-26 Hastifaba robusta Cooper, n. sp Dorsal, lateral, ventral, and end views of holotype; Hanover zone, loc. 28, X 30 112 27-32 Hastifaba spinosa Cooper, n. gen. and n. sp. 27-30, Dorsal, lateral ventral and end views of genoholotype; 31-32, inside views of right' and left valves of paratype, showing articulation, Colin zone, loc. 96, X 30 Note small spines on anterior end, fig. 28 m 33-37 Hastifaba pervidgata Cooper, n. sp. 33, Inside view of paratype- 34-37 dorsal, lateral, and end views of holotype; Jamestown zone, loc' 52, X 30 11]L 162 Illinois State Geological Survey Bulletin 70, Plate 18 Illinois State Geological Survey Bulletin 70, Plate 19 expanation of plate 19 Figures Page 1-9 Sansabella laevis (Warthin). Dorsal, lateral, and end views; 1-3, 7-9 re- versed male forms; Liverpool zone, loc. 16; 4-7 Female, Oak Grove beds loc. 20, X 40 116 10-11 Sansabella amplectans Roundy. Dorsal and lateral views; Liverpool zone, loc. 16, X 40 114 12-13 Lochriella ampla Cooper, n. sp. Dorsal and lateral views of holotype; Bogota zone, loc. 106, X 30 114 14-17 Sansabella bolliaformis (Ulrich and Bassler). Dorsal, lateral, ventral, and end views; "Centralia" zone, loc. 82, X 40 115 18-19 Lochriella? angusta Cooper, n. sp. Dorsal and lateral views of holotype; Bogota zone, loc. 19, X 40 114 20-22 Kloedenella carbonica Cooper, n. sp. Dorsal, lateral, and end views of holotype; Cohn zone, loc. 96, X 30 114 23-24 Lochriella elongata Cooper, n. sp. Dorsal and lateral views of holotype; Bogota zone, loc. 95, X 30 114 25-26 Sansabella brevis Cooper, n. sp. Dorsal and lateral views of holotype; Liverpool zone, loc. 16, X 40 115 27-29 Sansabella exilis Cooper, n. sp. Dorsal, lateral, and end views of holotype; Liverpool zone, loc. 16, X 40 116 30-35 Sansabella carbonaria Cooper, n. sp. Dorsal, lateral, and end views of re- versed forms. 33-35, Holotype, 30-32, paratype; LaSalle zone, loc. 88, X 40 115 [165 Explanation of Plate 20 Figukes Page 1-2 Microparaparchites cuneatus (Warthin). Dorsal and lateral views; Lons- dale zone, loc. 59, X 50 118 3-4 Microparaparchites ovatus Cooper, n. sp. Dorsal and lateral views of holo- type ; Liverpool zone, loc. 16, X 40 119 5-8 Cyathus striatus Cooper, n. sp. Dorsal, lateral, ventral, and end views; Seville zone, loc. 6, X 40 117 9-11 Microparaparchites elongatus Cooper, n. sp. Dorsal, ventral, and end view of holotype; Oak Grove beds, loc. 20, X 40 119 12 Microparaparchites angustus Cooper, n. sp. Lateral view, left valve of holotype; Hanover zone, loc. 26, X 40 118 13-15 Microparaparchites cornutus Cooper, n. sp. Dorsal, lateral, and end views of holotype; Liverpool zone, loc. 18, X 40 118 16-18 Microparaparchites brazoensis (Coryell and Sample). Dorsal, lateral, and end views ; Lonsdale zone, loc. 62, X 40 118 19-20 Microparaparchites quadrat us Cooper, n. sp. Dorsal and lateral views of holotype ; Brereton zone, loc, 37, X 40 119 21-23 Sargentina tumida Cooper, n. sp. Dorsal, lateral, and end views of holo- type ; "Centralia" zone, loc. 80, X 40 117 24-26 Microparaparchites wapanuckensis (Harlton). Dorsal, lateral, and end views ; Oak Grove beds, loc. 20 X 40 119 27-34 Paraparchites claytonensis Knight. Dorsal, lateral, and end views; Seville zone, loc. 4, X 15 120 35-36 Sansabella whitei Bradfield. Dorsal and lateral views; Lonsdale zone, loc. 62, X 40 . . ._. 117 37-39 Sansabella sulcata f Roundy. Dorsal, lateral, and end views; Exline zone, loc. 65, X 30 116 40-41 Sargentina elongata Cooper, n. sp. Dorsal and lateral views of holotype; Little Vermilion zone, loc. 102, X 40 117 42-43 Sansabella ovale Cooper, n. sp. Dorsal and lateral views of holotype; Little Vermilion zone, loc. 103, X 40 116 166 Illinois State Geological Survey Bulletin 70. Plate 20 Illinois State Geological Survey Bulletin 70, Plate 21 Explanation of Plate 21 Figures Page 1-2 Moorites indentus Cooper, n. sp. Dorsal and lateral views of holotype; Exline zone, loc. 66, X 50 122 3-4 Moorites punctus (Wilson). Dorsal and lateral views; Liverpool zone, loc. 16, X 50 123 5-6 Moorites knighti (Wilson). Dorsal and lateral views; "Centralia" zone, loc. 82, X 50 122 7-10 Moorites elongatusi (Jones and Kirkby). Dorsal and lateral views. 7-8, Brereton zone, loc. 37; 9-10, Trivoli zone, loc. 69, X 50 122 11-17 Moorites minutus (Warthin). Dorsal and lateral views, the latter showing variable pattern of surface ornamentation. 11-12, Lonsdale zone, loc. 62; 13-11, "Centralia" zone, loc. 82, X 50. 14-15, Interior views show- ing absence of transverse "teeth" of Youngiella 122 18-19 Moorites icapanuckensis (Harlton). Dorsal and lateral views; Lonsdale zone, loc. 63, X 50 123 20-21 Moorites spiciferus (Wilson). Dorsal and lateral views; Seville zone, loc. 6, X 50 123 22-27 Paraparchites exiguus Cooper, n. sp. Dorsal, lateral, and end views. 22-24, Paratype, Lonsdale zone, loc. 62, X 40; 25-27, holotype, Seville zone, loc. 5, X 30 120 28-30 Paraparchites fabula Cooper, n. sp. Dorsal and lateral views of holotype; Lonsdale zone, loc. 62, X 50 120 31-34 Paraparchites semireticulatus Cooper, n. sp. Dorsal, lateral, and end views of holotype ; Seville zone, loc. 4, X 20 120 35-36 Paraparchites dispar Cooper, n. sp. Dorsal and lateral views of holotype; Lonsdale zone, loc. 62, X 40 120 37-38 Proparaparchites parallelus Cooper n. sp. Dorsal and lateral views of holo- type; Lonsdale zone, loc. 62, X 40 121 39 Paraparchites inornatust (McCoy). Lateral view, right valve; Trivoli zone, loc. 63, X 20 120 40-43 Paraparchitella ovata Cooper, n. gen. and n. sp. Dorsal, lateral, ventral, and end views of genoholotype; Seville zone, loc. 6, X 40 121 169 INDEX Valid species in italics, species listed in synonomy in bold face type; species described on pages in italic. A Pages Acknowledgments 9 Acronotellidae 39 Aechmina? gibberosa 40 Aechminidae 40 Ardmorea 21, 40 gibberosa 20, 26, 40, 129 Ardmore basin 22 Albanella gouldi 98 Amphissites 17, 97 adjunctio 30, 97, 157 allerismoides 107 alticostatus 22, 97, 157 carinatus 31, 97, 157 centronota transversa 109 centronotus 29, 30, 98, 157 centronotus elongatus 21, 28, 98, 157 congruens 30, 99, 157 dattonensis 101 edsonae 102 geneae 102 geni ...102 gregeri 102 girtyi 20, 28, 99, 157 hextensis 108 irregularis 101 mesacostata 99 minuta 102 parvus 99, 157 pinguis 102 robustus 26, 29, 100, 157 rothi 31, 100, 157 roundyi 21, 29, 100, 157 simplicissimus 108, 109 sullivanensis 103 transversus 21, 23, 100, 157 wapanuckensis 108 Atoka group 15, 18 fauna 19 Argilloecia regularis 57 subelliptica 59 B Bairdia 17, 23, 40 acetalata 46, 54 acuminata ' t 0, 129 altifrons 20, 23, 40, 129 ampla 27, .',0, 129 angulata 49 angusta 20, 41, 129 ardmorensis 20, 41, 45, 129 auricula 45 48 beedei 24, 30, 33, 41, 129 [171 Bairdia, Cont'd. Pages beedei abrupta 42 beedei inflata 42 bidorsalis 42 blakei 31, 33, 42, 51, 129 chasae 40 ciscoensis? 28, 42, 129, 134 citriformis 24, 43, 129 concava 34, 43, 129 coryelli 23, 28, 43, 130, 134 crassa 23, 24, 26, 42, ^, 51, 130 crassimarginata 31, 44, 130 demissa 33, M, 130 dissimilis 19, 44, 130 dornickliillensis 48 garrisonensis 32, 45, 130 gibbosa 43 cf. glennensis ^5, 54, 130 grahamensis 50 harltoni 20, 45, 130 haworthi 46 hispida 42 hispida alta 42 hooverae 30, 46, 130 hoxbarensis 24, 28, 40, 46, 54, 130 hurtwitzi 31, 33, 46, 130 kingi 32, 47, 130 kingi compressa 47 longirostris ; 46 lunata 30, 47, 130 marginata 48 menardensis 22, 26, 47, 130 menardvillensis . .23, 26, 27, 48, 130, 134 monstrabilis 24, 30, 33, 48, 133 moorei 42 nebraskensis 54 nitida 42, 43 oklahomaensis 29, 48, 133 pennata 19, 22, 49, 133, 134 peracuta 22, 26, 49, 133, 134 pinnula 32, 33, 49, 133 plebia compressa 47 pompilioides 28, 30, 43, 49, 133 regularis 27, 50, 133 cf. rhomoidea 32, 50, 133 rogatzi 54 samplei 51 schaurothiana 20, 50, 133 scholli 31, 32, 51, 133 shideleri 54 seminalis 30, 48, 51, 133 spinosa 28, 52, 133 subcitriformis 50 subelongata 45,. 46, 54 summa 29, 52, 133 Bairdia, Cont'd. Pages symmetrica 28, 52, 133 texana 41 trojana 54 tumida 51 ventricosa 43 verwiebei 32, 52, 134 whitesidei 20, 24, 53, 134 ivrefordensis 42 Bairdiacypris 53 acuminata 26, 53, 134 ardua 31, 33, 53, 134 deloi 29, 53, 134 haydenbranchensis 30, 54, 134 nebraskensis 23, 27, 54, 134 shideleri 23, 26, 54, 134 trojana 24, 54, 134 Bairdiidae 17, 40 Bankston Fork fauna 25 Basslerella 69 acuminata 26, 29, 96, 145 firma 20, 26, 69, 145 lacrimosa 26, 33, 69, 145 obesa 26, 69, 70, 145 ovata 29, 32, 33, 70, 145 timrallela 26, 70, 145 pulchra 95 rostrata 26, 10, 145 Basslerina 88 limata 93 regularis 94, 96 Belle City formation 32 Beyrichia emaciata 91 tuberculo-spinosa 78 Beyrichiella bolliaformis 115 ' bolliaformis tumida 115 gregaria 110 Bogota cyclothem 12, 13, 17 fauna 21 Boskydell sandstone 20 Brereton cyclothem 15 fauna r: 24 Bronson fauna 28 Brouillet coal 12 Burroughs cyclothem 13 Bythocypris 55 angularis 57 bullifera 56 centralis 56 cooki 56 deesensis 57 disparilis 29, 55, 134 faba 76 gallowayi 76 haydenbranchensis 54 hoxbarana 57 mytilliformis 57 quadrata 29, 55, 134 palopintoensis 58 parallela 58, 59 pediformis 55-59 procerus 59 [172] Bythocyjwis, Cont'd. Pagws scapha 56, 58 simillima 59 subpediformis 26, 32, 55, 134 texensis 59 tomlinsoni 58, 59 tumidus 66 tumidus magnus 67 C Gandona 17, 23, 65 bairdioides 31, 65, 142 planidorsata 23, 66, 142 salteriana 23, 31, 66, 142 Carbondale 15, 21 Carbonia agnes 66 agnes rugulosa 66 agnes subrugulosa 66 fabulina subangulata 69 lenticularis 76 pungens 78 tumida magna 67 Carbonita 17, 21, 66 agnes 26, 66, 142 fabulina inflata 66 inflata 31, 33, 66, 142 magna 32, 67, 142 orbiculata 20, 68, 142 roederinana 66 tenuis 31, 68, 142 tumida 66 Carlinville cyclothem 13 Caseyville group 15 Cavellina 17, 23, 70 altoides 73 angusta 22, 10, 141 bisecta 22, 70, 141 cavellinoides 26, 71, 141 cumingsi 27, 11, 141 daubeana 27, 71, 145 equalis? 21, 22, 23, 71, 145 expansa 26, 72, 145 fittsi 22, 72, 145 footei 28, 33, 72, 145 jejuna 27, 72, 145 laevis 22 25, 72, 145 lata 22, 25, 73, 145 lintris 26, 73, 145 lirata 32, 73, 145 minuta 27, 73, 146 nebrasce?isis 32, 33, 13, 146 ovidiformis 31, 32, 77/, 146 pulchella 22, 30, 31, 74, 146 rotunda 24, 29, 77,, 146 subpulchella 31, 1), 146 symmetrica 30, 31, 33, 14, 146 tongiaf 28, 33, 7/,, 146 Cavelinella casei 22, 72 "Centralia" fauna 28 Cherokee fauna 21 Chester 15, 19 ostracodes 9 Pages Chonetes transversalis zone 17 Chonetina zone 17 Colin cyclothem 12, 13 fauna 31 Collecting localities 35 Collinsville fauna 28 Cornigella 78 longispina 79 minuta 79 pushmatahensis 79 tuberculospinosa 78 Coryella stovalli 115 Coryellina 55 firma 57 Coryellites 17, 55 centralis 21, 27, 56, 134 contracta 23, 56, 134 cooki 22, 56, 134 elongata 22, 25, 56, 134 firma 20, 33, 57, 137 johnsoni 27, 57, 137 loioelli 21, 22, 23, 57, 137 mytilliformis 32, 57, 137 ovata 23, 33, 57, 137 palopintocnsis 20, 33, 58, 137 parallela 21, 22, 25, 58, 137 pediformis 20, 33, 57, 58, 137 scotti 26, '58, 137 simillima 21, 22, 25, 5.9, 137 subelliptica 22, 33, 56, 137 texensis 25, 33, 59, 137 tomlinsonella 21, 23, 59, 137 "Craborchard" limestone 12 fauna 24 Curlew cyclothem 19 Cutler fauna 25 Cyathus 21, 117 striatus 20, 111, 166 Cyclothem 15 Cypridae 17, 65 Cythere ample 40 gloria 74 haworthi 102 kingi 47 plebia compressa 47 schaurothiana 50 Cythereis ardmorensis 39 Cytherella calcar 109 elongatus 122 footei 72 intermedia 74 laevis 72 missouriensis 74 ovidiformis 74 nebraskensis 73 symmetrica 75 tongia 75 wewokana 74 Cytherellidae 17, 70 Cytheridae 69 [173] D Pages Darwinula 17, 23,78 hollandi 78 pungens 23, 78, 146 Des Moines series 15, 17, 18 fauna 21 Discoidella 101 convexa? 26, 101, 158 lingulata 29, 33, 101, 158 perminuta? 32, 101, 158 "Divide" cyclothem 13 Dornick Hills group 24 Douglas fauna 31 Drepanellidae 78 E Eastern Interior basin, map 10 Bast Mountain formation 24 Ectodemites 101 dattonensis 30, 101, 158 edsonae 34, 102, 159 geneae 30, 102, 157 harltoni 19, 20, 102, 157 plummeri 20, 103, 157 sullivanensis 30, 103, 158 Effingham cyclothem 13 Ellipsella 109 ampla 109 bradfieldi 22, 24, 110, 161 calcar 33, 109, 161 distenta ,. .109 Exline limestone 23 fauna 27 F Fabalicypris 17, 59 acuminata 22, 60, 137 dispar 22, 60, 137 minuta 20, 21, 60, 137 plana 22, 60. 137 regularis 19, 20, 60, 138 tenuis 28, 61, 138 wetumkaensis 28, 61, 138 wileyensis 19, 23, 61, 138 Ferdinand limestone //, 20 fauna 20 Flannigan cyclothem 12, 13 Foraminifera 9 "Fresh water" types 32 Fulda limestone / /, 19 fauna 19 Fusulina, zone 17 Fusulinella zone 17 G Geisina 110 gallowayi 24, 110, 161 gregaria 23, 24, 25, 110, 162 jolliffiana 25, 110, 162 warthini 23, 25, 111, 162 Gila cyclothem 13 Pages Gimlet fauna 26 Glyptopleura 21, 79 coryelli 27, 30, 31, 79, 146 irregularis 30, 79, 146 spinosa 79 Glyptopleuridae 79 Glyptopleurina minuta 122 Greenup limestone 12, 13 fauna 34 Gutschickia 17, 23, 68 deltoidea 68 levis 23, 68, 142 ninevehensis 31, 68, 142 ovata 23, 68, 142 subangulata 32, 69. 142 H Hanover limestone 23 fauna 23 Harltonella 63 ardmorensis 64 elongata 64 macropleura 64 robusta 64 Hastifaba 17, 23, ill pervulgata 25, 111, 162 robusta 23, 112, 162 spinosa 31, 111, 162 Hayden Branch formation 30 Healdia 17, 19, 23, 79 alba 30, 79, 149 angulate 82 arcuata 82 asper 23, 80, 149 aspinosa 27, 28, 80, 149 bicornis 28, 80, 149 boggyensis 20, 22, SO, 149 bovicornis 83 bythocyproidea 64 cara 27^_ SI, 149 carinata 30, 81, 149 carterensis 21, 22, 23, 81, 149 cincta 27, 28, 81, 149 cisconesis 86 colonyi 27, 28, 81, 149 compressa 82 coryelli 33, 82, 150 deesensis 81 denisoni 84 ehlersi 29, 82, 150 elegens 20, 25, 82, 150 fabalis 20, 82, 150 formosa 27, 83, 150 glennensis 20, 24, 82, 83, 150 granosa 21, 23, 83, 150 leguminoides 57 limacoidea 23, 27, 83, 150 longa 83, 84 longula 20, 8J,, 150 malotti 86 marginula 21, 22, 84, 150 Healdia, Cont'd. Pa<;kn masoni 32, 84, 150 nucleolata 23, 84, 86, 150 oblonga 21, 27, 85, 150 cf. obsolens 30, 85, 150 oklahomaensis 24, 32, 85, 150 rectis 23, 85, 150 simplex 29, 33, 86', 153 spinosa 21, 27, 30, 86 150 usitata 26, 86', 153 Healdiidae 79 Healdiacypris 86 acuminatus 22, 86', 153 perplexa 23, 87, 153 Herrin (see Brereton) Hicks cyclothem 12 fauna 28 Hollina 87 emaciata 91 gran if era 91 grahamensis 91 obsita 95 radlerae 95 tricollina 95 tuberculospinosa 78 Hollites 88 papillosus 94 Hollinella 17, 87 bassleri 90, 94 buehleri 96 bulbosa 90 burling amensis 33, 89, 153 crassimarginata 31, 89, 153 cushmani 28, 90, 153 dentata 25, 90, 153 digitata 96 elongata 24, 91, 153 emaciata 33, 90, 91, 153 fortscottensis 92, 96 gibbosa 33, 91, 153 grahamensis 31, 91, 153 grandis 27, 29, 92, 153 harltoni 90, 91 inflata 94 kellettae 21, 22, 23, 92, 96, 154 levis 23, 24, 27, 93, 154 limata 25, 31, 93, 154 limbata 90 menardensis 89, 96 minuta 21, 22, 9k, 154 moorei 33, 94, 154 nowataensis 26, 94, 154 oklahomaensis 25, 33, 94, 154 ovata 96 pulchra 24, 90, 95, 154 radlerae 30, 95, 154 regularis 27, 96, 154 shawnensis 28, 33, 96, 154 ulrichi 92, 97 154 verrucula . 89 warthini 24, 27, 96, 154 Hollinellidae 17, 87 Hustedia miseri zone 15 [174] I Pages Illustrations 7 Introduction 9 Iowa 15 J Jackfork sandstone 18 Jamestown fauna 25 Jolliff formation 22 Jonesina 112 acuneata 109 ampla 109 arcuata 110 biformis 20, 112, 162 bolliaformis 115 bolliaformis tumida 115 -bradyana 27, 112, 162 craterigera 110 deesensis 26, 110, 112, 162 dulia 24, 112, 162 elongata 33, 113, 162 gallowayi 110 gregaria 110, 111 hoxbarana 109 infrequens 29, 113, 162 mccoy i 109 oklahomensis 94 subquadrata 27, 32, 113, 115, 162 texana 76 trisulcataf 27, 113, 162 K Kansas City fauna 28 Kellettina 103 montosa 21, 29, 103, 158 robustaf 27, 32, 103, 158 vidriensis 103 Kirkbya 104 arcuata? 27, 31, 104, 158 bendensis 19, 20, 104, 158 canyonensis 105 centronotus 98 clarocarinata 106 firma 25, 104, 158 inornata 20, 21, 105, 158 kellettae 31, 105, 158 knighti 105 magna 19, 24, 28, 105, 158 pergrandis 106, 161 permiana 104 permiana varica 104 perplexa 107 punctata 29, 106, 161 reflexa 19, 106, . 161 Kirkbyella 21, 106 cf. gutkei 19, 106, 161 Kirkbyidae 17, 97 Kirkbyina laevis 116 Kloedenella 21, 114 carbonica 31, 114, 165 Pages Kloedenellidae 109 Kniglitina 107 allerismoides 22, 107, 161 ampla 32, 107, 161 harltoni 30, 107, 161 hextensis 108, 161 kellettae 22, 108, 161 texana 107 L Lampasas series 18 Lansing fauna 30 LaSalle cyclothem 13, 31 fauna 30 Leperditellidae 17, 117 Little Vermilion limestone 14 fauna 32 Liverpool fauna 22 Livingston cyclothems 12, 13 limestone 13 fauna 30 Locality list, map 10 Lochriella 17, 114 ampla 33, 114, 165 angustus 27, 114, 165 elongatus 32, 114, 165 Lonsdale fauna 26 M Macoupin cyclothem 12, 13 fauna 29 Macrocypris 61 bicurvata 34, 61, 138 delicatula 61 garrisonensis 26, 61, 138 illinoiensis 29, 62, 138 lenticularis 34, 62, 138 menardensis 21, 24, 27, 62, 138 teretis 21, 23, 25, 62, 138 Marmaton fauna 23 McLeansboro 15, 21, 31 Mesolobus mesolobus zone 15 striatus zone 15 Microcheilinella 66 bicornuta 29, 63, 138 inflata 31, 63, 138 minuta 20, 63, 138 quadrata 24, 63, 138 unispinosa 32, 63, 138 Microparaparchites 17, 21, 118 angustus 23, 118, 166 brazoensis 23, 25, 27, 118, 166 cornutus 22, 118, 166 cuneatus 26, 118, 166 elongatus 21, 22, 25, 119, 166 ovatus 21, 22, 24, 119, 166 quadratus 24, 119, 166 wapanuckaensis 21, 25, 119, 166 Midcontinent 15 Millersville fauna 30 [175] Pages Missouri series 15, 17 fauna 27 Monoceratina 39 ardmorensis 19, 39, 129 bradfieldi 32, 39, 129 lawrencevillensis 39 leioisi 26, 3,9. 129 macoupeni 26, 39, 129 Moorea elongata * 122 Moorites 121 elongatus? 24, 33, 122, 169 indentus 27, 33, 122, 169 knighti? 20, 33, 122, 169 minutus 20, 122, 169 punctus 22, 27, 123, 169 sjnciferus 20, 23, 123, 169 wapanuckensis 20, 28, 123, 169 Morrow group 15, 18 fauna 19 N Newton cyclothem 13, 14, 17 fauna 32 Nuferella infrequens 113 O Oak Grove fauna 22 Offa? perminuta 101 Omega limestone 12, 13, 14 fauna 32 Otterville formation 22 P Paraparchitella 17, 20, 121 ovata 121, 169 Paraparchites 120 brazoensis 118 claytonensis 20, 120, 166 cuneatus 118 dispar 26^ 120, 169 exiguus 20, 27, 120, 169 fabula 26, 120, 169 inornatus? 28, 120. 169 latidorsalis 118, 119 oblongus 118 ottervillicus 119 perminutus 101 semicircular is 20, 120, 169 thomasi 119 wapanuckensis 119 Pawnee formation 24, 26 Permian 15 Pedee formation 31 Piasa fauna 25 Plates and explanations 127 Pokeberry limestone 12 Polytylites 21 ivapanuckensis 19, 108, 158 Proparaparchites 17, 121 parallelus 26, 121, 169 Pushmataha series 19 R Pages References 124 Roundyella 108 simplicissima 21, 10H, 109, 161 S Sansabella 114 amplectans 22, 1 V h 165 bolliaformis 29, 115, 165 bradyana 112 brevis 32, 115, 165 carbonaria 27, 31, 115, 165 exilis 22, 110, 165 laevis 22, 1 Id, 165 ovale 28, 32, 110, 166 sulcata? 27, 110, 166 whitei 23, 29, 1 17, 166 Sansabelloides edmistoni 76 texana 76 Sargentina 17, 21, 117 elongata 32, 117, 166 tumida 29, 117, 166 Seaborne fauna 21 Seminolites 21, 87 compressus 87 elongatus 33, 87, 153 truncatus 31, 33, 87, 153 Seville limestone 12, 20 fauna 20 Shaw Point cyclothem 13 Shawnee fauna 32 Shelby cyclothem 13 Shoal Creek limestone 11, 12, 13 fauna 28 Shumway cyclothem 13, 14 fauna 32 Silenites 75 asymmetrica 20, 75, 146 fabalis 21, 22, 24, 76, 146 lenticularis 23, 24, 25, 76, 146 silenus 33, 76, 146 South Bend formation 24 Sparland cyclothem 15 fauna 32 Spirorbus 17 Stanley shale 18 Stanton formation 30 Stratigraphic summary 11 distribution of ostracodes 15 St. David fauna 23, 24 Sulcella 76 harrisi 77 sulcata 20, 33, 76, 149 warthini 77 Summers series 19 Summum zone 17 fauna 23 Systematic descriptions 39 ri76] T Pages Ti Valley series 18, 19 Tradewater group 15, 21 Triceratina wrefordensis 39 Triticites zone 17 Trivoli fauna 28 U TJlrichia montosa 103 robusta 103 tuberculospinosa 78 V Virgil series 17 fauna 31 W Wabaunsee fauna 34 Wapanucka limestone 19 Waylandella 21, 63 ardmorensis 24, 64, 141 bythocyproidea 21, 6I h 141 cuyleri 25, 64, 141 deesensis 64 dispar 21, 22, 23, 6J h 141 Waylandella, Cont'd. Pages obesa 21, 22, 24, 65, 141 regularis 21, 22, 65, 141 symmetrica 22, 6-7. 141 vulgaris 20, 21, 65, 141 Wayland shale 25 West Virginia 18 Whwplella 66, 67 carbonaria 67 cuneiformis 66 deltoidea 68 depressa 66 ninevehensis 68 Wiley fauna 21 Willis coal 15 Woodbury cyclothem 13 fauna 34 Worland formation 24, 26 Y Youngiella convergens 122 elongata 122, 123 gracilis 122 knighti 122 minutus 122 puncta 123 spicifera 123 wapanuckensis 123 177]