URBANA 'LUNOIS STATE GEOLOGICAL SURVEY 3 3051 00000 0806 Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/uppermississippi86wins STATE OF ILLINOIS William G. Stratton, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Vera M. Binks, Director 19 5 9 UPPER MISSISSIPPIAN AND PENNSYLVANIAN MEGASPORES AND OTHER PLANT MICROFOSSILS FROM ILLINOIS Marcia R. Winslow BULLETIN 86 ILLINOIS STATE GEOLOGICAL SURVEY JOHN C. FRYE, Chief URBANA, ILLINOIS ILLINOIS S'ATfc GEOLOGICAL $H*»R| LIBRA i f- UPPER MISSISSIPPIAN AND PENNSYLVANIAN MEGASPORES AND OTHER PLANT MICROFOSSILS FROM ILLINOIS Marcia R. Winslow ILLINOIS STATE GEOLOGICAL SURVEY BULLETIN 86 Urbana, Illinois 1959 PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS STATE OF ILLINOIS HON. WILLIAM G. STRATTON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION HON. VERA M. BINKS, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Hon. Vera M. Binks, Chairman W. H. Newhouse, Ph.D., Geology Roger Adams, Ph.D., D.Sc, Ll.D., Chemistry Robert H. Anderson, B.S., Engineering A. E. Emerson, Ph.D., Biology Lewis H. Tiffany, Ph.D., Pd.D., Forestry Dean W. L. Everitt, E.E., Ph.D., University of Illinois President Delyte W. Morris, Ph.D., Southern Illinois University GEOLOGICAL SURVEY DIVISION John C. Frye, Ph.D., D.Sc, Chief (3833—2500—9-59) STATE GEOLOGICAL SURVEY DIVISION Urbana, Illinois. FULL TIME STAFF Enid Townley, M.S., Geologist and Assistant to the Chief JOHN C. FRYE, Ph.D., D.Sc, Chief Helen E. McMorris, Secretary to the Chief EMERITI M. Leighton, Ph.D., D.Sc, Chief, Emeritus Velda A. Millard, Junior Assistant to the Chief M. Arthur Bevan, Ph.D., D.Sc, Principal Geologist, Emeritus Gilbert H. Cadv, Ph.D., Senior Geologist, Head of Coal Section, Emeritus Robert J. Piersol, Ph.D., Physicist, Head of Physics Section, Emeritus GEOLOGICAL GROUP M. L. Thompson, Ph.D., Principal Geologist Frances H. Alsterlund, A.B., Research Assistant COAL Jack A. Simon, M.S., Geologist and Head Robert M. Kosanke, Ph.D., Geologist John A. Harrison, M.S., Associate Geologist Paul Edwin Potter, Ph.D., Associate Geologist William H. Smith, M.S., Associate Geologist Kenneth E. Clegg, M.S., Assistant Geologist Margaret A. Parker, M.S., Assistant Geologist David L. Reinertsen, A.M., Assistant Geologist OIL AND GAS A. H. Bell, Ph.D., Geologist and Head Lester L. Whiting, M.S., Geologist Wayne F. Meents, Associate Geological Engineer Margaret O. Oros, B.A., Assistant Geologist Thomas W. Smoot, Ph.D., Assistant Geologist Jacob Van Den Berg, M.S., Assistant Geologist Richard H. Howard, M.S., Research Assistant Ronald A. Younker, B.S., Research Assistant PETROLEUM ENGINEERING Carl W. Sherman, M.S., Petroleum Engineer and Head Richard F. Mast, B.S., Assistant Petroleum Engineer ENGINEERING GEOLOGY AND TOPOGRAPHIC MAPPING George E. Ekblaw, Ph.D., Geologist and Head William C. Smith, M.A., Associate Geologist CLAY RESOURCES AND CLAY MINERAL TECHNOLOGY W. Arthur White, Ph.D., Geologist and Head Walter E. Parham, M.S., Assistant Geologist GROUND WATER GEOLOGY AND GEOPHYSI- CAL EXPLORATION George B. Maxf.y, Ph.D., Geologist and Head Robert E. Bergstrom, Ph.D., Geologist Merlyn B. Buhle, M.S., Geologist James E. Hackett, Ph.D., Geologist Grover H. Emrich, M.S., Assistant Geologist John P. Kempton, M.A., Assistant Geologist Wayne A. Pryor, Ph.D., Assistant Geologist Lowell A. Reed, B.S., Assistant Geologist Arthur J. Zeizel, M.S., Assistant Geologist Margaret J. Castle, Assistant Geologic Draftsman (on leave) INDUSTRIAL MINERALS J. E. Lamar, B.S., Geologist and Head James C. Bradbury, Ph.D., Geologist Donald L. Graf, Ph.D., Geologist James W. Baxter, Ph.D., Assistant Geologist Meredith E. Ostrom, Ph.D., Assistant Geologist STRATIGRAPHY AND AREAL GEOLOGY H. B. Wtllman, Ph.D., Geologist and Head Elwood Atherton, Ph.D., Geologist Charles W. Collinson, Ph.D., Geologist Herbert D. Glass, Ph.D., Geologist David H. Swann, Ph.D., Geologist T. C. Buschbach, M.S., Associate Geologist Lois S. Kent, Ph.D., Associate Geologist John A. Brophy, Ph.D., Assistant Geologist Romayne S. Ziroli, B.A., Research Assistant Robert W. Frame, Supervisory Technical Assistant Joseph F. Howard, Assistant PHYSICAL CHEMISTRY CHEMICAL GROUP Grace C. Finger, B.S., Research Assistant COAL CHEMISTRY J. S. Machin, Ph.D., Chemist and Head Daniel L. Deadmore, M.S., Associate Chemist Neil F. Shimp, Ph.D., Associate Chemist Juanita Witters, M.S., Associate Physicist ANALYTICAL CHEMISTRY O. W. Rees, Ph.D., Chemist and Head L. D. McVicker, B.S., Chemist Emile D. Pierron, Ph.D., Chenist William J. Armon, M.S., Associate Chenist Charles W. Beeler, M.A., Assistant Chenist David B. Heck, B.S., Research Assistant Effie Hetishee, B.S., Research Assistant John K. Kuhn, Research Assistant Steven Pusztaszert, Research Assistant George R. James, Technical Assistant Benjamin F. Manley, Technical Assistant X-RAY W. F. Bradley, Ph.D., Chemist and Head G. R. Yohe, Ph.D., Chemist and Head Joseph M. Harris, B.A., Research Assistant CHEMICAL ENGINEERING H. W. Jackman, M.S.E., Chemical Engineer and Head R. J. Hf.lfinstine, M.S., Mechanical and Adminis- trative Engineer B. J. Greenwood, B.S., Mechanical Engineer Robert L. Eissler, M.S., Associate Chemical Engineer James C. McCullough, Research Associate (on leave) Walter E. Cooper, Technical Assistant John P. McClellan, Technical Assistant Edward A. Schaede, Technical Assistant FLUORINE CHEMISTRY G. C. Finger, Ph.D., Chemist and Head Donald R. Dickerson, M.S., Associate Chemist Laurence D. Starr, Ph.D., Associate Chemist MINERAL ECONOMICS GROUP W. H. Voskuil, Ph.D., Principal Mineral Economist Hubert E. Risser, Ph.D., Mineral Economist W. L. Busch, A.B., Associate Mineral Economist ADMINISTRATIVE GROUP EDUCATIONAL EXTENSION George M. Wilson, M.S., Geologist and Head I. Edgar Odom, M.S., Assistant Geologist Betty J. Hanagan, M.S., Research Assistant GENERAL SCIENTIFIC INFORMATION Autumn B. Fulton, A.B., Technical Assistant Joan Sevon, B.A., Technical Assistant PUBLICATIONS Dorothy E. Rose, B.S., Technical Editor Meredith M. Calkins, Geologic Draftsman Betty M. Lynch, B.Ed., Assistant Technical Editor Llewellyn W. Cooper, B.S., Assistant Geologic Draftsman Mira N. Rodwan, Assistant Geologic Draftsman MINERAL RESOURCE RECORDS Vivian Gordon, Head Hannah Fisher, Supervisory Technical Assistant Kathryn L. Gronberg, B.S., Research Assistant Barbara Getty, B.A., Technical Assistant Marilyn J. Lilly, Technical Assistant Barbara L. Scott, B.A., Technical Assistant Elizabeth Speer, Technical Assistant Lucretia Stetler, B.A., Technical Assistant Danguole Tan, B.S., Technical Assistant TECHNICAL RECORDS Berenice Reed, Supervisory Technical Assistant Miriam Hatch, Technical Assistant Helen E. Schroeder, Technical Assistant LIBRARY Olive B. Ruehe, B.S., Geological Librarian Carol S. Madden, B.A., Technical Assistant FINANCIAL RECORDS Velda A. Millard, In Charge Virginia C. Sanderson, B.S., Clerk IV Marjorie J. Hatch, Clerk-Typist III Joan P. Roseman, Clerk-Typist II Janice Schulthes, Clerk-Typist I * Divided time Topographic mapping in cooperation United States Geological Survey SPECIAL TECHNICAL SERVICES William Dale Farris, Research Associate Beulah M. Unfer, Technical Assistant A. W. Gotstein, Research Associate Glenn G. Poor, Research Associate* Gilbert L. Tinberg, Technical Assistant Wayne W. Nofftz, Supervisory Technical Assistant Donovon M. Watkins, Technical Assistant Mary Cecil, Supervisory Technical Assistant Nancy A. Anvari, Technical Assistant Ruby D. Frison, Technical Assistant CLERICAL SERVICE Mary M. Sullivan, Clerk-Stenographer III Rita J. Nortrup, Clerk-Stenographer II Sandra Lou Edminson, Clerk-Stenographer I Anita F. Roosevelt, Clerk-Stenographer I Susan E. Shannon, Clerk-Stenographer I Edna M. Yeargin, Clerk-Stenographer I Leona Whites ell, Clerk-Typist II Dorothy J. Gerdes, Clerk-Typist I Linda G. Goldman, Clerk-Typist I Kathryn J. Hicks, Clerk-Typist I William L. Mathis, Messenger-Clerk II AUTOMOTIVE SERVICE Glenn G. Poor, In Charge* Robert O. Ellis, Automotive Shop Foreman David B. Cooley, Automotive Mechanic Everette Edwards, Automotive Mechanic with the July 1, 1959 RESEARCH AFFILIATES Douglas A. Block, M.S., Wheaton College J Harlen Bretz, Ph.D., University of Chicago S. E. Harris, Jr., Ph.D., Southern Illinois Univer- sity A. Byron Leonard, Ph.D., University of Kansas Thomas G. Perry, Ph.D., Indiana University Carl B. Rexroad, Ph.D., University of Houston Walter D. Rose, B.S., University of Illinois Alan J. Scott, Ph.D., University of Texas Paul R. Shaffer, Ph.D., University of Illinois Norman Street, Ph.D., University of Illinois Harold R. Wanless, Ph.D., University of Illinois Paul A. Witherspoon, Ph.D., University of California Frederick D. Wright, M.S., University of Illinois CONSULTANTS George W. White, Ph.D., University of Illinois Ralph E. Grim, Ph.D., University of Illinois CONTENTS Page Introduction ' Purpose and scope 8 Previous investigations 9 Preparation and examination of samples 10 Spore development and morphology H Descriptions of megaspores and "large" spores 15 Genus Triletes 15 Genus Triletes? 48 Genus Cystosporites 50 Genus Spencerisporites 54 Genus Calamospora 59 Genus Monoletes 61 Genus Parasporites 63 Descriptions of "small" spores 63 Genus Punctatisporites 63 Genus Reticulatisporites 64 Genus Renisporites n. gen 64 Other microfossils of the plus 65-mesh residues 67 Sporangial masses of Densosporites 67 Seed membranes 6/ Miscellaneous plant microfossil 68 Animal (?) membranes 68 Location of samples 69 Spore distribution /J Introduction '^ Mississippian System 73 Chester Series '•* Pennsylvanian System Caseyville Group '' Tradewater Group °^ Carbondale Group 89 McLeansboro Group -^ Discussion Upper Mississippian "^ Pennsylvanian References Plates and Explanations 103 ILLUSTRATIONS Text Figure Page 1. Orientation of radially symmetrical spores 2. Orientation of bilaterally symmetrical spores 3. Scatter diagrams illustrating megaspore shrinkage upon drying 14 4. Length-breadth measurements of spores of Renisporites conjossus 6:> 5. Length-breadth proportions of spores of Renisporites conjossus 65 6. Illinois counties from which macerated coal samples were examined 68 7. Stratigraphic occurrence of spores in upper Mississippian and lowermost Pennsylvan- ian rocks ."*.*'" 8. Stratigraphic occurrence of seven genera and spores of five sections of Triletes in upper Mississippian and Pennsylvanian rocks 9. Spore distribution chart •• • * ■ Plate Page 1. Genus Triletes 105 2. Genus Triletes 106 3. Genus Triletes 109 4. Genus Triletes 110 5. Genus Triletes 113 6. Genus Triletes 114 7. Genus Triletes 117 8. Genus Triletes 118 9. Genus Triletes 121 10. Genus Triletes and Triletes? 122 11. Genus Triletes? and Cystosporites 125 12. Genus Cystosporites 126 13. Genus Spencerisporites and Calamospora 129 14. Genus Monoletes and Parasporites 130 15. Genus Punctatisporitesy Reticulatisporites, Renisporites, Densosporites, and seed mem- branes 133 16. Seed membranes, miscellaneous plant micro fossils, and membranes of animal (?) origin 134 TABLES Table Page 1. Comparative data on megaspores of the Triletes hirsutus and T. globosus types ... 41 2. Geographic locations in Illinois 69 3. Geographic locations in states other than Illinois 72 UPPER MISSISSIPPIAN AND PENNSYLVANIAN MEGASPORES AND OTHER PLANT MICROFOSSILS FROM ILLINOIS MARCIA R. WINSLOW ABSTRACT A preliminary investigation of land plant megaspores and other resistant plant parts from the plus 65-mesh maceration residues of coals and carbonaceous layers of upper Mississippian (Chester Series) and Pennsylvanian age indicates that plant megaspores are useful in correlation, especially on a local scale, and may in the future aid in de- lineating coal swamp heterosporous plant distribution. The study established that megaspore assemblages of Chester age are dominated by spinose lageniculate and fibrous-coated megaspores representing an arborescent lepido- dendrid-lepidocarp flora. Megaspores of the Caseyville Group indicate a more diverse heterosporous flora, including both herbaceous and arborescent lycopsids. Spinose lageniculate, fibrous-coated, auriculate, zonate, and deltoid-bladdered spores dominate the assemblages. The oldest occurrences of sigillarians and medullosans are represented by spinose aphanozonate and monolete spores, respectively. Sphenopsids also are represented. From the base of the Tradewater Group, to and including the Pope Creek Coal, the assemblages are distinguished by their great diversity of zonate megaspores, by abundant triangulate megaspores, and by the occurrence, apparently restricted, of one new genus. The upper part of the Tradewater Group is characterized by smooth lageniculate spores, abundant monolete medullosan spores, and by the lowest occurrence of spores with lateral bladders. The assemblages from the Summum (No. 4) Coal to the top of the Carbondale Group are characterized by an abundance of smooth aphanozonate spores of sigillarian alliance, but, except for the absence of zonate spores, are otherwise similar to those of the Trade- water Group. The assemblages of the McLeansboro Group, not investigated extensively, appear to be characterized by heavy-apexed, smooth lageniculate-type spores, smooth aphanozonate spores, auriculate spores, monolete medullosan spores, both deltoid- and lateral-bladdered spores, and by the absence or extreme rarity of the fibrous-coated spores and zonate spores. Zonation of megaspores from upper Mississippian and Pennsylvanian coals is pos- sible, based on the differentiation of lageniculate spores, restricted ranges of some spores, and, in some instances, marked variation in abundance. INTRODUCTION decreased in frequency as distance from the ., . . ,, old shoreline increased. As the plants The spores described here are actually , , t , , n 1 . f changed or evolved, more or less parallel the resistant outer coats or the spores or °, , . , , . , , . - , ,. _ , l morphological changes took place in the propagative bodies of the gametophytic ^ ^ The ^ q£ foJ ^ and generation of certain types of land plants Uen {n beds of yo is therefore that were abundant in the floras of Mis- q£ yalue {n ^ torrdation of coals and sissippian and Pennsylvanian age. A great other sedimentary rocks as weH as for pos- vanety of spore types were produced in sible paieobotanical implications. large numbers and widely dispersed, prin- Coals of Mississippian and Pennsylvanian cipally by wind and water. Eventually they age are composed largely of more or less were entombed in both continental and ma- chemically altered fossil remains of plants, rine sediments, although they were pro- such as the woody parts of stems and duced only b\ land plants. Such spores oc- branches, resins, waxes, cork, cuticle, and curred in greatest numbers closest to their spore coats. Although spore coats do not site of production, and in marine sediments make up the bulk of the coal, except in [7] s ILLINOIS STATE GEOLOGICAL SURVEY such unusual deposits as the Williamston Spore Coal of Michigan, they are commonly abundant. Because of their small size, less than 15/x to more than 10,000^, vast num- bers can be studied easily in the laboratory when they are isolated from coal by one of the various maceration techniques. The complex problem of correlation of Pennsylvanian coals in Illinois has been greatly simplified by Kosanke's (1950) in- vestigations of small spore occurrences. Be- cause all vascular plants produce small spores or their equivalents among plants of more advanced organization, such a study is of great value not only in the correlation of beds but also in the assessment of the total aspect of the flora existing during Pennsylvanian time. The megaspores, gen- erally the larger spores, are produced by only the heterosporous vascular plants and therefore yield information on only a seg- ment of the flora. However, the megaspore content of coal beds in European coal basins has been studied extensively for al- most thirty years and such studies have yielded valuable information on the corre- lation of coal beds and their relative age. Even in an area where the stratigraphic suc- cession is accurately known, the relative quantity and kinds of megaspores in dif- ferent coals have provided an accurate basis for comparing an unknown bed to known beds or correlating known beds across a fault zone (Dijkstra, 1946; 1949, fig. 1). Because fewer megaspores are produced and because they are generally much larger and heavier than the small spores, they probably were not dispersed as widely as isospores and microspores. An uneven dis- tribution of plants throughout a coal swamp might be masked by the wide dis- persal of small spores, but the large spores might be used in interpreting the geo- graphic distribution of the heterosporous plants. In contrast to the intensive megaspore investigations carried on in Europe, very few such studies (Schopf, 1938; Cross, 1947; Arnold, 1950) have been reported in the United States. This is especially true of megaspores of Mississippian age. Purpose and Scope The plant megaspore assemblages and some other plant remains in the plus 65- mesh maceration residues, mainly of coals, were investigated to determine their possi- ble significance in the correlation of coal beds and in the delineation of heterospor- ous plant distribution in the coal swamps that existed periodically and sometimes extensively over Illinois and surrounding states during upper Mississippian and Penn- sylvanian time. General knowledge of the evolution and ecology of the heterosporous plants and of the occurrence and re-occurrence of their spores in various coal beds allows compari- son of successions with those found in other coal basins in the world. A general com- parison such as this adds to our knowledge of the geographic distribution and evolu- tion of ancient floras, but it does not imply intercontinental correlation of coal beds. Such information has shown the succession in the coal basins of Poland, Czechoslo- vakia, France, Turkey, and in the Ruhr Basin to be generally similar (Dijkstra, 1949). The coals in Illinois have been inten- sively studied and their content of small spores has been noted in previous reports. The coarse residues of the samples used in those investigations were available for study so that a comparison of the occurrences of some megaspores with the occurrences of their botanically related microspores was possible. Aside from the study by Horst (1955) on the coal beds of the Namurian A and B and Westphalian A in Poland, there is very little published information cover- ing both the large and small spore content of the same samples of coal. The investigation of upper Mississippian megaspores and their comparison with those of the lowermost Pennsylvanian were begun to determine whether megaspores could provide a ready differentiation for distinguishing Mississippian strata from the unconformably overlying Pennsylvanian strata, a key that would be especially useful in studies of drill cuttings and cores and PREVIOUS INVESTIGATIONS when gross lithologic distinctions are not apparent. The results and possibilities pre- sented supplement the results of more ex- tensive investigations by other methods. Schopf (1949, p. 511) pointed out that descriptive and taxonomic studies were likely to dominate pollen and spore re- search for many years, simply because the field to be explored is so enormous. In ad- dition he stated, "It does not follow that significant economic results will invariably follow initial exploratory studies; however, the history of paleontology in general is a sufficient insurance that reasonable benefits will come from progress in this work." A large part of this report is devoted to the description, some of it very detailed, ol plant megaspores, plus some illustration and discussion of spores that are larger than conventional small spores and may be ei- ther megaspores or small spores, and of pre- pollen, cuticle, and seed membranes that occur in the macerations with the mega- spores. The primary emphasis is on spores from the coals in the upper Mississippian Chester Series and in the Pennsylvanian Caseyville and Tradewater Groups, but those from some of the coals of the Carbon- dale and McLeansboro Groups are de- scribed in order to present a general over- all picture of plant megaspore distribution. Some material of late Mississippian and early Pennsylvanian age from areas outside Illinois also is included for comparative purposes. Many of the residues and slides examined had already been prepared in the labora- tories of the Illinois Geological Survey for other studies, and therefore no statistical approach to the relative abundance of meg- aspores from one coal to another, or even in segments in the same coal, could be valid. The terms "rare," "present," "com- mon," and "abundant" used relative to megaspore abundance are necessarily sub- jective because some of the samples were not collected for statistical analysis as were those on which Dijkstra (1946, 1955c) has reported. This report,, therefore, is a general and preliminary survey of the occurrence of megaspores in upper Mississippian and Pennsylvanian coals, preliminary in that the sampling of the individual coal beds was limited and the examination of spores from coals of the McLeansboro Group < ur- sory. Acknowledgments I am grateful to J. A. Simon, Head of the Coal Section of the Illinois State Geological Survey, for his interest in and encourage- ment of this investigation, and to Dr. John C. Frye, Chief of the Survey, for his sup- port. Dr. D. H. Swann collected some ol the Mississippian samples and provided guidance in the interpretation of the strati- graphic position of some of the previously collected samples. The advice and guid- ance regarding the stratigraphy of Illinois coals given by Dr. R. M. Kosanke and his contributions to discussions on problems of taxonomy, nomenclature, and interpreta- tion of some of the results made this report possible. PREVIOUS INVESTIGATIONS Kosanke, whose investigations on the small spores of Pennsylvanian coals of Illi- nois (Kosanke, 1947, 1950, 1954) are well known, has given (1950, p. 7-8) a general history of spore studies from the first ob- servations of fossil plant spores by Witham in 1833 through the important contribu- tions, principally concerning small spores, of the mid-1940's. Many major findings on Carboniferous megaspores also were re- ported during the period beginning with the study by Bennie and Kidston in 1886. Among the important studies done outside the United States are those of Zerndt (1930a, b, c, d; 1931; 1932a, b; 1934; 1937a. b; 1938a, b; 1940), Stach and Zerndt (1931), Kowalewska-Maslankiewiczowa (1932), Sa- habi (1936), Ibrahim (1933), Loose (1934), Wicher (1934a, b), Nowak and Zerndt (1936); from the United States are the stud- ies of Bartlett (1929), Schopf (1936a, b; 1938), and Schopf, Wilson, and Bentall (1944). Bailey (1936) briefly illustrated and described some megaspores. 10 ILLINOIS STATE GEOLOGICAL SURVEY Many contributions to the study of small spores, megaspores, and spores in organic association in cones have been made since 1944. Those particularly pertinent to the study of larger plant microfossils of Car- boniferous age outside the United States are studies by Dijkstra (1946; 1952a, b, c; 1955a, b, c; 1957), Kalibova (1951), Pierart 1956, 1957), Potonie (1954a, b), Potonie and Kremp (1954, 1955, 1956), and Horst (1955). Recent cone studies by Chaloner (1951; 1952; 1953a, b, c; 1954a; 1958a), Dijkstra (1958), Remy and Remy (1956), and, in the United States, by Felix (1954), Hoskins and Abbott (1956), and Chaloner (1956a, 1958a) to mention a few, give much valuable information as to the amount of natural variation in megaspores and their botanical alliances. Particularly pertinent studies on mega- spores and other plant fragments of upper Mississippian and/or Pennsylvanian age done in the United States are those by Cross (1947), Arnold (1948, 1950), Schemel (1950a), Chaloner (1954b), and Guennel (1954). Cross (1947) illustrated and briefly described megaspores found in coals of the Kanawha Group (Pottsville Series), Alle- gheny Series, and Monongahela Series from the Pennsylvanian of West Virginia and Kentucky. Arnold (1948) described several types of seed membranes found in the Pennsyl- vanian coals of the Michigan Basin and (1950) described and illustrated some of the megaspores found there. Schemel (1950a), in a report emphasizing small spores, described megaspores of two species from a Chester or Springer age coal of Utah. Chaloner (1954b) described and illustrated megaspores of Kinderhook or Osage age and of early Chester age from Michigan, Pennsylvania, and Indiana. Guennel (1954) gave a detailed description of spores of Triletes triangulatus from the Block Coal of Indiana. The study of spores contained in coal macerations began at the Illinois State Geo- logical Survey in 1931, under the supervi- sion of G. H. Cady, with an investigation of plant remains in maceration residues from column samples of the Herrin (No. 6) Coal of the Carbondale Group. McCabe (1931) illustrated some cuticle, vascular tissue, and spores from the Pope Creek and No. 5 Coals and (1933) reported his find- ings on the plant remains of the Herrin (No. 6) Coal in an unpublished doctoral dissertation at the University of Illinois. Henbest (1933) described some of the plant fragments of the Herrin (No. 6) Coal and (1935) described and illustrated a few meg- aspores of that coal. Schopf (1936a, b) also illustrated mega- spores of the Herrin (No. 6) Coal and de- scribed them under binomial designations. In 1938 he presented the detailed results of these investigations on the large spores, in- cluding prepollen, found in maceration residues of the Herrin (No. 6) Coal from southern Illinois. Other papers by Schopf (1941a, b; 1948), mainly on fructifications and seeds, presented aspects of the natural affinities and variations of spores. In 1944, Schopf, Wilson, and Bentall discussed the generic groups of Paleozoic spores. Later Schopf (1949) commented further on the taxonomic identity of some spores and re- viewed some of the important spore studies. Most previously published work on Illi- nois coal megaspores emphasizes the mega- spores of individual commercially impor- tant coals. The present study provides a gen- eral framework within which investigations concentrated on one or several coals over a large area can be related and therefore as- sume greater significance. PREPARATION AND EXAMINATION OF SAMPLES The process of coal maceration, the free- ing of resistant plant parts from the rest of the coal, as used at the Illinois State Geo- logical Survey, is a modification (see Ko- sanke, 1950, p. 8-11) of the method first de- scribed by Franz Schulze in 1855. In gen- eral the process consists of two phases: the partial oxidation of coal with Schulze's solu- tion (1 part aqueous solution of KClOo to 2 parts concentrated HNO;!), followed by the solution of the salts of the humic acids SPORE DEVELOPMENT AND MORRHOLOC.Y 11 by treatment with 10 percent KOH, and subsequent decantation. Some weathered coals require only the latter phases of the treatment, the oxidation phase having been completed by nature. Spores are isolated from clays, shales, and sandstones with HCL and HF treatments. Other spores may be picked from bedding planes of a sedimentary rock and merely cleaned with dilute HF. A summary of the various methods applicable to the iso- lation of organic matter from all kinds of rocks, in all degrees of induration, has been published recently by Sittler (1955). The 65-mesh (the figure indicates the number of meshes to the inch) Tyler screen has mesh openings of about 210 /a. The residue passing through the 65-mesh screen generally is stained in safranin Y and mounted under a cover slip with glycerine, diaphane, or balsam, and examined for small spore content. (A discussion of vari- ous mounting media and their advantages and disadvantages is given by Christensen [1954].) The coarse, plus 65-mesh residue may contain sporangial masses of small spores, megaspores, or large spores, spores rather small for "large" spores (200 to 400 fi), cuticle, seed membranes, waxy blebs, resin rodlets, fusinized wood and vascular fragments, and incompletely mac- erated coal fragments. Additional sieves may be used to separate the coarse residue into various size fractions. The coarse resi- dues commonly are stored in alcohol and glycerine in wax-sealed bottles. All coarse residues used in this study- were examined immersed in water in a petri dish under a binocular microscope at mag- nifications of 6X to 36 X. The large spores, some sporangial masses, cuticles, vascular tissues, and seed membranes were picked from the dish with a flattened needle. Sub- sequently the specimens were mounted dry on cardboard mounts or, as with the ma- jority of specimens, passed through alcohol to xylol and mounted in balsam on slides, the most permanent media for megaspore mounts. More than 1,000 balsam and dry mounts were examined. Descriptions and measurements are based largely on the examination of specimens mounted in balsam because the fine orna- mentation details are adequately observed only by transmitted light. This phase of the work was done on a research micro- scope at magnifications of 150X to 500 X. Photographs were taken on fine-grained film with both transmitted and reflected light. A red filter was used in photograph- ing some of the highly ornamented thick- walled megaspores in order to show details of the spore body and its ornamentation. SPORE DEVELOPMENT AND MORPHOLOGY The spores described and discussed in this report were largely, perhaps entirely, derived from vascular plants, the Tracheo- phyta. Many of the plants were large and treelike and are referred to as arborescent. Others grew close to the ground and are called herbaceous. All vascular plants pro- duce spores of some kind and have an alter- nation of sporophyte and gametophyte gen- eration during their life cycles. The mature plants, part of the sporo- phyte generation, produce spore mother cells, each of which produces four unicellu- lar spores of the gametophyte generation. Some vascular plants are homosporous, pro- ducing spores that germinate into multi- cellular gametophytes, which in turn pro- duce both male and female gametes. Other plants are heterosporous and bear: 1) mega- spores that germinate into multicellular fe- male gametophytes that produce female gametes and 2) microspores that germinate into multicellular male gametophytes that produce only male gametes. The union of female and male gametes initiates the sporo- phyte generation of the life cycle. Most spores are enclosed within a pro- tective coat that is resistant to chemical and physical attack. Because of this, the spore coats or exines, referred to generally as spores throughout this paper, commonly are well preserved in coals and many kinds of sediments. The gametophyte inside the spore coat is preserved only under excep- tional conditions. 12 ILLINOIS STATE GEOLOGICAL SURVEY Different plants produce spores of differ- ent sizes and shapes and, as plants evolved through time, the size, shape, and orna- mentation of the spores changed, although possibly not at the same rate as other ob- servable changes in the plants. Because of the great variety of spore types, their grad- ual change in appearance through geologic time, and the resistant nature of the spore coat, the spore assemblages found in any one sediment are likely to be different in composition from those found in older or younger beds. Also, because of possible geographic dif- ferences in the distribution of plants, the assemblages from the same bed may have a slightly different aspect from one area to another. Spores, especially microspores and isospores, are produced in great numbers, are small, and are widely dispersed by nat- ural agencies such as wind and water cur- rents. Although megaspores are generally larger, sometimes very large, and are pro- duced by only a segment of the floral popu- lation — the heterosporous plants — they, too, are sometimes widely dispersed. How- ever, their distribution is more likely to be restricted to an area close to their site of production. Because we have very little chance of de- termining whether a fossil spore performed a male or female function in the life cycle, unless cone studies have provided the knowledge, an arbitrary lower size limit of 200 fx has been given for megaspores (Guen- nel, 1952). Dijkstra (1946, p. 21) also re- views the size problem. The size limit sug- gested follows from using the Tyler sieve, with a mesh opening of about 210 p, to sep- arate the fine from the coarse residue. Guennel further proposes the use of the term "miospore" for all spores or sporelike bodies less than 200 /x in size. These could include isospores, microspores, small mega- spores, pollen, and prepollen. The spores of Spencerisporites are iso- lated spores similar to those occurring in some of the cones of Spencerites, reported as eligulate and homosporous. Thus, on available evidence, the spores referred to Spencerisporites would be considered iso- spores. Renisporites spores, rather small in comparison with most megaspores, may be megaspores, isospores, or microspores. Monoletes and Parasporites are considered prepollen. However, most of the spores described here are megaspores of the ar- borescent and herbaceous lycopsids and lepidocarps. The larger spores show considerable dif- ferences in size. In Cystosporites three mem- bers of the original tetrad are abortive, much smaller than the fertile specimens, and sometimes much different in aspect. I - Tetrahedral Tetrad 2- Tetragonal Tetrad Text fig. 1 (above). — Orientation of radially sym- metrical spores. a. Spores in tetrad association. b. Proximal view of a single spore showing tri- lete suture and contact areas. c. Lateral view of single spore. Text fig. 2 (below). — Orientation of bilaterally symmetrical spores. a. Spores in tetrad association. b. Proximal view of single spore showing mono- lete suture and contact areas. c. Transverse lateral view of single spore. SPORE DEVELOPMENT AM) MORPHOLOGY 13 Spores are characteristically either radi- ally (trilete suture, text fig. 1) or bilaterally (monolete suture, text fig. 2) symmetrical, the type of symmetry being controlled by the division of the spore mother cell. For descriptive purposes, spores are oriented with reference to their original position in the tetrad grouping (text figs. 1, 2; pi. 9, fig. 3). The side of a spore toward, and in- cluding, the original areas of mutual con- tact in the tetrad is designated as proximal (side, surface, or hemisphere). The side of the spore external to, or away from, the cen- ter of the tetrad is distal. The axis of a radially symmetrical spore passes through the center of the original tetrad. The apices of the four spores at the proxi- mal poles originally touched in the tetrad. Bilaterally symmetrical spores have one axis of symmetry through the long dimen- sion of the spore and another through the proximal surface of the spore and the cen- ter of the distal surface. The contact areas are the two or three surfaces of mutual con- tact in the original tetrad. The trilete suture (pi. 15, fig. 2), or line of dehiscence, forms along three radiating lines; the trilete ray refers to one extension of the trilete suture or its expression as lips or as a fold. The monolete suture forms along a single line (pi. 15, fig. 5a). Some spores may possess very insignificant lips bordering the suture, others may have straplike lips (pi. 9, fig. 4a), and still others may have lips surmounted by an apical prominence (pi. 3, fig. 13). Those features influenced by the contact relationship of spores during growth in a tetrad are designated as haptotypic by Wodehouse (1935). The contact areas may be bounded by arcuate ridges, flanges, or ornamentation which may or may not ex- tend over the entire distal surface. Distal ornamentation, in reference to megaspores, is not generally strictly limited to the distal hemisphere, but extends distally from the arcuate ridges or contact areas. Specifically inherited characters, such as distal orna- mentation, of which the type, shape, and size is relatively constant for any one spe- cies, are designated as emphytic by Wode- house (1935). Some spores (pi. 13, fig. 2; pi. 14, fig. 11) possess bladders or membranous air sacs which are attached to the spore coat. Still others possess a wrinkled inner membrane (pi. 9, fig. 8a, b; pi. 10, fig. 9), sometimes variously ornamented, referred to as an en- dosporal membrane by Schopf (1938) , the mesosporium of Dijkstra (1946) and H^eg, Bose, and Manum (1955). Original spore shape may vary from sac-shaped, to spheri- cal, to distinctly oblate. The shape is usu- ally more or less distorted by compression, the manner of compression being deter- mined by both the original shape and the presence and kind of ornamentation. Thus, the compressional form is usually charac- teristic of a species, although other species may also show the same form. In descriptions of the Illinois megaspores particular attention is given to differences in ornamentation noted on the lageniculate megaspores. This general type of mega- spore, showing some morphological varia- tions, is known from beds as old as upper- most Devonian, through the Mississippian and Pennsylvanian, and into the Permian. Therefore, any slight variation in ornamen- tation may be helpful in differentiating these megaspores. In contrast, those apicu- late and smooth aphanozonate megaspores, Triletes mamillarius Bartlett (sensu Dijk- stra) and T. glabratus Zerndt (sensu Dijk- stra), and the spores of T. triangulatus Zerndt (sensu Dijkstra) are the least em- phasized as to possible distinctions based on ornamentation because of practical limita- tions to the investigation. In the smooth aphanozonate megaspores, possible distinctions would have to be based on thickness of spore coat, length of rays relative to spore diameter, or on the size ranges of the spore diameter. The actual size of a spore, or the range of a group of spores, may mean little relative to its botan- ical alliance. Bochenski (1936) illustrates the wide range in spore size in cones of Sigillariostrobus Czarnockii (400 to 2700//. in one cone and 450 to 2900 ^ in another) . 14 ILLINOIS STATE GEOLOGICAL SURVEY 1500/x q 1300/1 I lOO/i 900/1 700/i Triletes romosus Triletes mamillarius immature megaspores 700/i 900^ I lOO/i 1300/1 1500/i 1700/t SPORE BODY DIAMETER-WET | I lOO/i 5 900/i >- Q O oo 700/i 700/i 900/i I lOO/i 1300/1 1500/1 1700/1 SPORE BODY DIAMETER-WET Text fig. 3. — Scatter diagrams showing the spore body dimensions of megaspores of Triletes ramosus Arnold, T. mamillarius Bartlett (sensu Dijkstra), and T. brasserti Stach and Zerndt, before and after drying. Line of best fit determined by eye. Shrinkage averages a little less than 20 percent. All speci- mens from the Willis Coal (maceration 625 B), Gallatin County, Illinois. The smaller, immature spores are distin- guished by a thicker wall and a more tri- angular shape. Although actual size does not seem to be indicative for distinction, the relative proportion of one feature to another may be a more satisfactory basis for distinction. Because many megaspores have been ob- served to shrink noticeably when mounted dry, a preliminary investigation on the amount of shrinkage was made on the spores of three species: Triletes brasserti, T. ramosus, T. mamillarius. All these specimens were well preserved, those of T. brasserti abundantly represented, in a sam- ple chosen from the lower part (maceration 625B) of the Willis Coal that had been macerated in Schulze's solution in August of 1945 and stored in alcohol and glycerine until February 1956 when the specimens were transferred to water and various meas- urements were made. Each specimen was transferred to a cardboard mount and al- lowed to dry. The same measurements GENUS T RILE lis 15 were then taken again, unless, of course, the specimen had cracked on drying. The maxi- mum diameter oi each specimen, both wet and dry, is well shown on the scatter dia- grams that are given in text figure 3. The shrinkage observed ranges from less than 10 percent to more than 35 percent and has a pronounced effect on the means of the max- imum diameters of the spores of the three species. In contrast to this large amount of shrinkage, some spores (T. mamillarius, sensu Dijkstra) from a Casey ville age coal (maceration 795) macerated in 1954 showed a consistent 5 percent shrinkage. Probably many factors contribute to the observed differences in size between wet and dry specimens. The preservation of the spores, the type of maceration method used, the length of time specimens are stored, and the kind of medium in which they are stored, all may affect total size when observed wet as opposed to the size when observed dry. The differences in di- mensions, if any, of a single specimen, trans- ferred first from water to alcohol, then to xylol, and then mounted in balsam have not been checked as yet. That some shrinkage occurs, even when freshly macerated specimens are dried, can- not be denied. Extensive, laborious tests would have to be run in order to determine the effect of different maceration processes and length of storage time on the observed differences in size. It is possible that some of the observed distinctions between spores described by different authors, from differ- ent coals or from different areas, may be resolved as only the effect of differential shrinkage rather than the result of any bo- tanical distinctions in the plants producing these spores. In any event, this is but one facet to the study of fossil megaspores. The actual expectable differences possible with- in a cone or between cones of the same plant will not be fully appreciated until many more cone studies have been reported upon. Probably the most expedient solution to the problem is to gi\e measurements based on either dry or balsam-mounted speci- mens, indicating clearly which type is used. The descriptions of the spores of the different species arc based on my observa- tions of spores, principally from Illinois coals, and not on previously published de- scriptions unless otherwise indicated, so that the descriptions and si/e measurements may differ somewhat from previously pub- lished ones. Nomenclature of fossil spores in this pa- per is that determined by the International Rules of Botanical Nomenclature. These rules are adhered to by most authors in order that the system of reference be under- stood internationally, and are simple, pre- cise, and, above all, stable. The genera re- ferred to in the present paper are artificial in that they are based on spores of plants, in contrast to the criteria used to determine genera of modern plants, and may corre- spond generally to categories of familial, or higher, rank. As research continues, espe- cially that on fossil fructifications, these artificial groupings will become restricted to as small a natural category as is possible with fossil plants. Individual interpreta- tion of the magnitude of differences that determine species or varieties within a gen- eric group varies, as does the interpreta- tion of genera based on fossil spores. In time the nomenclature may express the taxonomic position of the plants more closely. DESCRIPTIONS OF MEGASPORES AND "LARGE" SPORES Genus Triletes (Bennie and Kidston) ex Zerndt, 1930 Type species: Triletes glabratus Zerndt, 1930c Megaspores referred to Triletes are radi- ally symmetrical, marked by a trilete suture on their proximal surfaces. The extremities of the trilete rays may be connected by arcu- ate ridges. Elaborate processes may be de- veloped at the outer edges of mutual con- tact of the sister spores in the tetrad. Distal sin laces are smooth to ornamented; proxi- mal surfaces, if ornamented, are generally ornamented to a lesser degree than are dis- tal surfaces. Schopf (1938) pointed out that 16 ILLINOIS STATE GEOLOGICAL SURVEY no spores of well established species of Tri- letes are less than 300 ^ in size. Some spores, for example those of T. superbus, are as much as 4100 ^ in over-all diameter. The genus is believed to represent a nat- ural grouping of heterosporous free-sporing lycopsids, somewhat equivalent to a sub- order in the normal classification. Potonie and Kremp (1954, 1955, 1956) believed that Triletes is an invalid and ille- gitimate generic designation and therefore redefined and re-emphasized some of Ibra- him's (1933) generic names and established new genera to which they referred mega- spores. The confusion arose because of a mistaken but consistent attribution of the generic name Triletes to Reinsch. Triletes, implying relationship with the lycopods, was used by Bennie and Kidston in 1886 in describing megaspores, although not in combination with specific epithets. It was in the sense of Bennie and Kidston's usage, not Reinsch's, that Bartlett (1929) and Zerndt (1930c) applied it in binomial com- bination to megaspores. In 1930 Zerndt re- ferred some of his specimens to those first described by Bennie and Kidston. Bennie and Kidston should be considered the effec- tive authors of Triletes which became vali- dated no later than 1930 by Zerndt's publi- cation. Laevigatisporites (Ibrahim) Potonie and Kremp (1954) , therefore, is a later synonym of Triletes. The use or nonuse of the ge- neric names adopted or initiated by Po- tonie and Kremp is a taxonomic decision to be made at present by each individual, depending on his interpretation of the taxonomic circumscription of Triletes. Such decisions also must be made at the species level. Dijkstra (1946) has inter- preted some species as having a wide range of spore variation, an interpretation con- firmed in certain instances by cone studies, whereas other authors advocate a narrow circumscription about the holotype speci- men. The individual acceptance of a broad or narrow circumscription can be expressed in the taxonomy by use of such a term as "sensu Dijkstra." If each author clearly states his intent and adequately describes and illustrates his material, future modifica- tion, which always comes with expanded knowledge, will be relatively simple. Schopf (1938) proposed the following sec- tional divisions of Triletes based on com- parative spore morphology: Aphanozonati, Lagenicula (Bennie and Kidston), Auricu- lati, Triangulati. The spores referred to any one section are believed to be more closely related to one another than to spores referred to other sections. Such a classifica- tion attempts to indicate the phylogeny and natural plant relationships as closely as is possible on the basis of available evidence. Dijkstra (1946) proposed the use of the section Zonales (Bennie and Kidston) be- cause he believes that some of the zonate spores are not closely allied to those typi- cally referred to the section Triangulati. In addition, he proposed that the auriculate spores should be grouped with the aphano- zonate spores, rather than segregated in a separate section. In the present paper, spores of Triletes are referred to the following sections: La- genicula, Aphanozonati, Auriculati, Zo- nales, and Triangulati. Sectio Lagenicula (Bennie and Kidston) Schopf, 1938 Spores of the Lagenicula section of Tri- letes are generally medium-sized, more or less prolate originally, and typically later- ally compressed, possessing an apical prom- inence formed by the elongated and up- raised portions of the three contact faces. Arcuate ridges are commonly developed, but extreme zonal appendages are lacking (Schopf, 1938). Spore coat is variable in thickness with a smooth to spinose surface. Spores of T. horridus and T. rugosus are typical of this section. Lageniculate spores have been found in Lepidostrobus fructifi- cations (Chaloner, 1953b; Felix, 1954) in association with Lycospora-type micro- spores, a lepidodendrid alliance. Potonie (1954b) stated that the mega- spores of the Lepidodendraceae never bear "fimbriae ramiferes" as do those of the Bothrodendraceae (Triletes praetextus, for example). However, there is a tendency for GENUS TRILETES 17 the spinose lageniculate spores found in earliest Chester and older rocks to bear dou- ble or even ramifying processes. The earliest such occurrence known from this study is that of megaspores of T. crassiaculeatus, each bearing only a few double-tipped spines. Spinose lageniculate-type mega- spores in older Mississippian deposits bear such spines in increasing number and de- gree of ramification. The coat of the spinose lageniculate spores appears more or less punctate. Wicher (1934a) in a description of Apicu- lati-sporites latihirsutus (Triletes horri- dus) noted that the surface is "sehr fein netzforming bis punktiert." The coat some- times appears very finely meshed and, in this respect, is similar to the coat of some fertile and abortive spores of Cystosporites (especially C. verrucosus). Schopf (1938, p. 28) suggested that there appears to be a progressive simplification of the apical prominence during the Car- boniferous. This seems to be more or less true for the spinose spores of the section. Among the smooth forms, spores of Triletes levis (interpreted as T. nudus by some) oc- cur in younger coal beds than do those of T. rugosus and possess more highly devel- oped apical prominences. Dijkstra (1958) described some similar spores from Sigil- lariostrobus cf. major. The relationship of T. levis with the section Lagenicula may be only apparent, however, because Lyco- spora, usually associated with lageniculate spores, is absent from coal beds containing T. levis. It is probably unwise to segregate the lageniculate spores as a distinct genus until the relationship of spores of T. in- dianensis, T. splendidus, T. globosus, T. hirsutus, T. praetextus, and T. levis to the spores typical of the section is understood more clearly. The earliest occurrence of lageniculate megaspores bearing double or forked spines is in the older coals of the Chester Series. The more commonly illustrated spinose lageniculate spores are usually characteris- tic of the Caseyville Group. Smooth lage- niculate spores first occur in the Rock Island (No. 1) and Murphysboro Coals, and arc present in the younger coals of the Tradewater and Carbondale Groups. Those with a highly developed apical prominence appear to be restricted to coals of the Mc- Leansboro Group. In this study, smooth and spinose lageniculate spores have not been observed together in the same sample. Triletes subpilosus (Ibrahim) Schopf, Wilson and Bentall, 1944 (sensu Dijkstra, 1946) Plate 2, figures 1-5 1933 Setosi-sporites subpilosus Ibrahim, p. 27; pi. 5; fig. 40. 1944 Triletes subpilosus (Ibrahim) Schopf, Wil- son, and Bentall, p. 26. 1946 Triletes subpilosus (Ibrahim) Dijkstra, p. 46-47; pi. 11, figs. 116-128. 1955 Lagenicula subpilosa (Ibrahim) Potoni£ and Kremp, p. 120; pi. 4, fig. 21. Description. — Megaspores typical of spe- cies of medium size, more or less bottle- shaped, with distinct apical prominence, generally compressed obliquely; maximum equatorial diameter, measured perpendicu- lar to the spore axis, from 550 to 1270 ^ (mean 960 ^ for 25 specimens). Apical prominence, measured from base of lips, generally between 100 and 175 yu. in height, up to 300 ix in width; lips thick, obscuring suture, rarely open. Contact areas and lips, especially area at base of lips, set with small spines (pi. 2, fig. 1) generally about 5 ^ in diameter and 5 ^ in height. Distal spore coat set with scattered spines ranging from 56 to 128 ^ in maximum length* and 10 to 30 ^ in width basally. Spines more or less parallel-sided, usually straight to gently recurved, and fluted bas- ally, blunt to ball-tipped. Spines adjacent to contact areas are shorter, more delicate, and more crowded, but on some spores rather widely spaced. No subsidiary distal spines present. Spore coat punctate, 7 to 15/x thick, as little as 4 /x thick on contact areas, yellow to orange-brown by transmitted light. * Range in maximum length is the range of maxima observed on all spores, not the minimum-maximum range in length. This range of maxima is considered more meaningful because spores of reveral species may chow comparable minima in spine length. Therefore, in the species above, 56 (i is the shortest maximum spine length ob erved on any spo:e; 120 fl is the longest maximum length observed. ILLINOIS STATE GEOLOGICAL SURVEY Discussion. — Megaspores typical of Tri- letes subpilosus are smaller, have shorter spines and a thinner spore coat than those of T. subpilosus forma major. The spines may be rather widely spaced, even around the contact areas and somewhat short and blunt ended (pi. 2, fig. 1) . The apical ex- pansion is of the same configuration as in T. subpilosus forma major but somewhat lower. In contrast, spores of T. horridus have unornamented, expanded, flaplike lips and possess distal subsidiary spines. The spores of Triletes subpilosus, includ- ing variants, exhibit a wide range in over- all diameter and spine length, both gener- ally decreasing from older to younger strata. The measured specimens, here referred to as spores typical of the species and de- scribed above, are from three coals in the Caseyville Group. Those from the Battery Rock Coal range from 650 to 1030 fx in equatorial diameter (mean 898 [x for 8 spores) and possess spines from 56 to 128 yu, in maximum length. Those from an older coal (maceration 795) range from 555 to 1110 fi in equatorial diameter (mean 883 ti for 10 spores) and possess spines from 66 to 123 /x in maximum length. Spine length is generally less than 100 tx. These two assem- blages are very similar, but their mean di- ameters are somewhat greater than that originally cited by Dijkstra (1946, p. 46) for T. subpilosus. It is possible that the spores of Triletes subpilosus are more closely comparable with those of T. subpilosus forma major, originally defined by Dijkstra (1952a, p. 103) as ranging from 500 to 1300 ^t (mean 866 ix for 50 spores) in total axial length. Also included here as typical of T. sub- pilosus are seven rather large spores from the oldest coal from a diamond drill core in Wabash County, Illinois (maceration 798), in the Caseyville Group. These have an un- usually narrow range in equatorial diam- eter, 1010 to 1270 ^ (mean 1142 /x), and pos- sess spines from 56 to 103 /x in maximum length. Such a narrow size range is not normal; the discovery of a few smaller ex- amples, in addition to the few large ones that were found, would lower the mean con- siderably. Although the mean diameter of these few spores is at least 100 ^ greater than that of spores of T. subpilosus forma major from two older formations (Chester, mace- rations 143, 166), the latter have, with a sin- gle exception, longer spines. Spores of Triletes subpilosus are present in the youngest coal of the Black Creek Group and are abundant in the overlying coals of the Mary Lee Group in the Warrior Basin, Alabama. They also are known from the Indiana French Lick Coal (maceration 151) and from the shale (maceration 163) above the Pinnick Coal of Indiana. Previously Reported Occurrences. — Spores typical of the species occur in Upper Westphalian A and Westphalian B in the Netherlands (Dijkstra, 1946) , and in Upper Westphalian B to Middle Westphalian C in the Ruhr Basin (Potonie and Kremp, 1955). Occurrence. — Megaspores of Triletes sub- pilosus are abundant and dominant in the Battery Rock Coal (maceration 587) and in a coal (maceration 795) of the Caseyville Group. They are common in an unnamed coal (maceration 797) and are rare in the "Makanda" Coal (maceration 142) and lowest unnamed coal in a diamond drill core from Wabash County (maceration 798), all of the Caseyville Group in Illinois. Triletes subpilosus forma major (Dijkstra) ex Chaloner, 1954 Plate I, figures 1-9 1950 Triletes subpilosus forma major Dijkstra, p. 871 (nom. nud.). 1952 Triletes subpilosus (Ibrahim) forma major Dijkstra (1952a), p. 103 (nom. nud.). 1954 Triletes subpilosus forma major Dijkstra, in Chaloner (1954b), p. 27; pi. I, fig. 4 (not pi. I, figs. 5, 6). Description. — Megaspores of medium size, more or less bottle-shaped with distinct apical prominence, usually compressed obliquely; maximum equatorial diameter, measured perpendicular to spore axis, from 465 to 1790 ^ (mean 1195 ^ for 74 speci- GENUS TRILETES 19 mens). Apical prominence rather triangu- lar in lateral outline (pi. 1, figs. 6, 8), from 125 to 340 fx in height from base of lips, usu- ally less than 200 p.. Lips rather thick, ob- scuring suture, rarely open. Trilete rays equalling about one-third the radius of the spore body; contact areas occupying about two-fifths the proximal hemisphere. Con- tact areas and lips, especially area at base of lips, generally heavily ornamented with small pointed spines 10 to 20^ in length and up to 10 ^ in width. Closely spaced distal spines from 90 to 340 n in maximum length, 10 to 30 /x in width basally. Spines more or less parallel- sided, extending outward from a fluted, hollow-appearing base to a blunt, pointed, or ball- to cup-shaped tip. Spines straight, sinuous, or gently refiexed; some appear ribbon-like (pi. 1, fig. 3), never forked. Spines generally more delicate, crowded, and about one-half the length of the distal spines at the margins of the contact area. No small subsidiary distal spines present. Spore coat punctate or minutely meshed, 7 to 20 n thick, thinnest in the contact areas, generally yellow to orange-brown by trans- mitted light. Discussion. — These spores are abundant in and characteristic of Chester age rocks. The small gradual decreases in total size, spine length, and spore coat thickness from oldest Chester to youngest Chester age meg- aspores are not considered adequately de- lineated at this time for taxonomic separa- tion. The spores of the four samples, upon which most of the measurements were made, seem to tall into two more or less dis- tinct groups within Triletes subpilosas forma major. Those from the Degonia (maceration 143) and Hardinsburg (mac- eration 166) Formations of Illinois have comparable mean diameters of 1015 /x (5 spores) and 970 /x (19 spores) with maxi- mum diameters of 1270 ^ and 1240 jX respec- tively. In contrast, spores from a coal in the Hardinsburg Formation (maceration 810) and from a coal in Bethel (Mooretown) Formation (maceration 943) of Kentucky have comparable mean diameters of 1315 /x (19 spores) and 1295 /x (31 spores) with maximum diameters of 1695 fx and 1790 p.. More than half of the spores from the coal in the Bethel (Mooretown) Formation pos- sess spines having a maximum length of more than 200 /x; one spore has spines up to 340 xt in length. In addition, spore coat thickness exceeds 15 to 16/x only in this older coal. All these spores have certain charactens tic features in common, also shared by the younger megaspores typical of the species. These features are the rather stunted-ap- pearing apical prominence, at least less ex- panded than that on spores of Triletes hor- rid us; a usually heavy ornamentation of contact areas and lips; more or less par- allel-sided spines, blunt to ball-tipped and fluted basally; the absence of small subsid- iary distal spines. The spores of macerations 143 and 166 are somewhat smaller than those described as Triletes subpilosus forma major by Chal- oner (1954b) from the Beaver Bend Lime- stone of Indiana. They are approximately the same size as, but with a thinner spore coat than, those described as T. cf. T. sub- pilosus forma major by Dijkstra (1957) from the Namurian of Scotland. However, the spine length and spore coat thickness of the latter are comparable with those of spores from the older Chester formations. These older spores are probably identical to those Chaloner describes from the Bea- ver Bend Limestone but have more exten- sive size limits. The other megaspores, of probable Kinderhook age, that Chaloner describes as T. subpilosus forma major are not characteristic of this species. Spores of Triletes subpilosus forma major in the lower part of the Chester bear some similarities to megaspores of T. crassiacu- leatus with which they may occur. How- ever, spores of T. subpilosus forma major are smaller, do not have the tall, expanded, apical prominence, lack subsidiary distal spines and forked spines, and have a thin- ner spore coat. Most of the spine tip features described by Bennie and Kidston (1886) are found on spores of Triletes subpilosus forma major. 20 ILLINOIS STATE GEOLOGICAL SURVEY An extreme development of the cup-shaped tip is shown by a small, probably immature spore (pi. 1, fig. 4). Some of the megaspores described by Horst (1955) as T. subpilosus may be similar to those of T. subpilosus forma major. Previously Reported Occurrences. — Spores of Triletes subpilosus forma major have 1 ( ( i reported from the Namurian A, B, and C of Turkey by Dijkstra (1952b), from the Namurian of Scotland by Dijkstra (1957), from the Dinantian and Namurian (?) of Scotland by Chaloner (1954b), and from the lower part of the Chester Series of Indiana by Chaloner (1954b). Occurrence. — Megaspores of Triletes sub- pilosus forma major are the dominant and characteristic megaspores of upper Missis- sippian coals. They are: 1) abundant in the coal in the Bethel (Mooretown) Formation (maceration 943) from Kentucky; 2) pres- ent in the coal in the Bethel (Mooretown) Formation of Indiana (macerations 834, 832, 468) ; 3) abundant in the coal in the Hardinsburg Formation (maceration 810) of Kentucky; 4) present in the coal in the Hardinsburg Formation (maceration 166), in the coal in the Tar Springs Formation of Scottsburg, Kentucky, and in the coal in the Vienna Formation (maceration 758) of Illinois; 5) abundant in the coal in the Vienna Formation of Illinois (macerations 168, 764, 842, 765, 687 A-B) and abundant to present in the Degonia Formation (macerations 143, 200) . Triletes horridus (Zerndt) Schopf, Wilson, and Bentall, 1944 (sensu Dijkstra, 1946) Plate 2, figures 6-12; plate 3, figure 1 1934 Lagenicula horrida Zerndt, p. 25-26, fig. 11; pL 28, figs. 1-5. 1944 Triletes horridus (Zerndt) Schopf, Wilson, and Bentall, p. 22. 1946 Triletes horridus (Zerndt) Dijkstra, p. 45- 46; pi. 12, figs. 129-136. (Dijkstra 's synonvmy, excluding Lagenicula I var. major of Ben- nie and Kidsion, accepted.) 1950 Lagenicula horrida Zerndt, in Arnold, p. 81- 82; pi. X, figs. 1-5. 1955 Lagenicula horrida Zerndt, in Potonie and Kremp, p. 119-120; pi. 20, fig. 4. Description. — Megaspores of medium size, more or less bottle-shaped with ex- panded apical prominence, usually com- pressed laterally; maximum equatorial di- ameter, measured perpendicular to spore axis, from 555 to 1305 ^ (mean 925 p for 34 specimens). Apical prominence well devel- oped, from 180 to 350 ^ in height from base of lip and up to 400 ll in width; lips gener- ally open. Trilete rays one-third or less of the spore radius; contact areas occupying one-half or less of the proximal hemisphere. Contact areas and lips occasionally bearing a few tiny spines. Distal spore coat ornamented with widely spaced spines from 50 to 160 ^ in maximum length and from 15 to 60 ^ in width. Spines extending from rather expanded hollow-ap- pearing bases, tapering to a fine point, sometimes ball-tipped and recurved, snorter and more closely spaced at the margins of the contact areas. Small, acuminate subsid- iary spines, 5 to 30 ^ in length and 3 to 15 ^ in width, generally present among the longer distal spines. Spore coat punctate or minutely meshed, 7 to 22 ix thick, generally thicker than 15/x, thinnest on contact areas, yellowish orange to reddish brown by transmitted light. Discussion. — Although these megaspores of Triletes horridus have a larger size range than that given by Dijkstra (1946), the spores correspond in their general morphol- ogy, especially in the expanded, often open, flaplike lips. Practically all the megaspores of T. horridus seen during this study pos- sess, in addition to the large distal spines, small, pointed, subsidiary, distal spines. The presence and abundance of these small excrescences generally is regarded as one of the most variable features of ornamentation of T. horridus megaspores. The subsidiary spines have been mentioned by Zerndt (1937a) and illustrated by Arnold (1950). Arnold noted their occurrence on about 80 percent of the specimens he examined. Chaloner (1953b) described the T. horri- . He noted the presence of the characteristic secondary folds on the contact area (1931, pi. 8, fig.' 25; 1934, pi. 26, fig. 4). Although Wicher (1934a) in his description of T. diffusopilosus — later synonym of T. praetextus (Dijkstra [1946], Potonie and Kremp [1955]) — did not men- tion the presence of the serrated upper mar- gin of the lips, his figure 23 on plate 8 showed some indication of this feature. There is some question whether or not the spores, from Appalachian Basin coals, illus- trated by Cross (1947, pi. I, fig. 20; pi. Ill, figs. 91-94) and designated as T. praetextus and T. praetextus var. I are properly refer- able to this species. The general occurrence of these spores, as reported by Dijkstra (1955a), is in the Westphalian B and C of most coal basins, although thev also are present in the West- phalian A in Turkey, and even in the Na- murian of Poland. More detailed records of previously reported occurrences were given bv Dijkstra (1946), Potonie and Kremp (1955) , and Horst (1955). Affinity. — These spores are, according to Potonie (1954a, 1954b), allied with the Bothrodendraceae. Occurrence. — Megaspores of Triletes praetextus are present but poorly preserved in the Battery Rock Coal (maceration 587) , Hardin County, Illinois; common and beautifully preserved in the shale (macera- tion 163) above the Pinnick Coal, Orange County, Indiana; abundant but poorly pre- served in the Pratt Coal from the Warrior Basin in Alabama. All these coal beds are of early Pennsylvanian age. Triletes echinoides Chaloner, 1951 Plate 6, figures !. 5 L954 Triletes echinoides Chaloner (1954b), | 29; pi. II, figs. 3, 4. Description. — Megaspores large, origin- ally more or less spherical, up to 2.55 mm in equatorial diameter (three complete specimens measuring 1.76, 2.15, and 2.55 mm) . Trilete rays highly developed (pi. 6, fig. 5b) ; lips fluted, up to 820 p in height at proximal pole, decreasing in height some- what towards extremities of the rays. Con- tact areas in some specimens delimited by weakly developed arcuate ridges, in some specimens bearing tapering spines up to 480 p in length (pi. 6, figs. 5a, 5b) . Distal spore coat bearing long tapering spines (pi. 6, fig. 4) up to 1690 ^t in length and 340 ^ in width, most commonly 700 to 900^ in length and 100 to 200 ^ in width. Spines fluted basally. Small spines variable in length and width, up to 100 ^ in length, occurring among the long distal spines. Discussion.— Chaloner's (1954b, p. 28-29) original description was based principally on fragmented specimens as is the one given above. Most of the specimens that I ob- served were either very poorly preserved and very much compressed or apparently fusinized. The high degree of compression probably accounts for the excessive maxi- mum diameter of the spines. These mega- spores, on the basis of both groups of meas- urements, have a diameter ranging from 1.76 to 2.66 mm, an apex ranging from 600 to 820 a in height, and distal spines ranging up to 1630 fx in length. Megaspores of this species are unique in their large size, highly developed lips, and long spines. Thev were first reported by Chaloner from the Beaver Bend Limestone of Indi- ana (early Chester) . The reported occur- rences are still restricted to beds of upper Mississippian age in the Appalachian and Eastern Interior Coal Basins of the United States. The botanical alliance of these unusual megaspores is unknown. Occurrence. — Megaspores were found mostlv as fragments in the upper part of the Menard and Golconda Formations in 48 ILLINOIS STATE GEOLOGICAL SURVEY the H. Forester No. 1 core, Perry County, Illinois, and in a plant bed believed to be near the base of the Glen Dean Formation (maceration 888) at Big Stone Gap, Vir- ginia. Spine fragments, possibly of this spe- cies, were noted in the coal in the Vienna Formation (maceration 687B) from John- son County, Illinois. No positively identi- fied fragments have yet been found in coals. Triletes eregliensis Dijkstra, 1952 1952 Triletes eregliensis Dijkstra (1952a), p. 102- 103; pi. VII, fig. 3. Triletes cf. T. eregliensis Plate 6, figure 6 Discussion. — The three spores found have equatorial dimensions of 940 ti, 1010 /x, and 1130^, respectively. They are matte brown by reflected light, opaque by transmitted light. Closely spaced, irregularly formed, distal papillae, up to 25 ^ in length, give a dark brown to black appearance to the dis- tal coat. Although the ornamentation is very similar to that shown by Dijkstra, these three spores are smaller, have slightly higher lips, and more prominent arcuate ridges, especially at the juncture of the ridges with the trilete rays. The ridges are similar to a very thick, short flange, the distal surface of which appears free of orna- mentation. Two of the spores, although partially torn apart, are still in tetrad asso- ciation (pi. 6, fig. 6) . Immature spores might be expected to have more prominent ridges than mature spores. Dijkstra originally described Triletes eregliensis — one complete spore and several broken ones — from the Westphalian D of Turkey. Pierart (1957) reports one small specimen (720 ^) from the Upper West- phalian C of Belgium. Occurrence. — These spores were found in one sample of the Tarter Coal (maceration 604A) , Fulton County, Illinois. Genus Triletes? Triletes? saturnipunctatus n. sp. Plate 10, figure 11 Description. — Spores are rather small for megaspores, originally somewhat oblate to disk-shaped, rounded triangular in equa- torial outline, ranging from 325 to 440 p in diameter (mean 400 ^ for 20 specimens) . Trilete suture is distinct, generally open; trilete rays extend more than two-thirds the spore radius, possessing no labial devel- opment. Spore coat is characterized by a robust equatorial rim up to 60 ^ thick, apparently consisting of two layers, a thin inner one about 4 to 5 /x thick and a thick outer layer. Thickness of spore coat at equator equals as much as 10 to 16 percent of the total spore diameter; diameter of inner spore cavity (six specimens) equals 71 to 78 per- cent of the total diameter. In side view, the outer margin of equatorial rim is rounded, occasionally sharp on poorly pre- served spores. Spore coat thins to as little as 5 fj, thick near proximal pole, decreases gradually to 10 ^ thick at distal pole. Spore coat is rarely folded, except for apical cor- ners of contact areas. Worn specimens com- monly lack central proximal surface, some of them also lack central distal surface so that only the dark circular rim remains. Spore coat is minutely but distinctly punctate, dark reddish brown to yellow by transmitted light, glossy and dark brown by reflected light. Holotype. — Maceration 916 slide 5, Pope Creek Coal (lower 4 inches), Mercer Coun- ty, Illinois (pi. 10, fig. 11). Discussion. — Except for size, spores of Triletes? saturnipunctatus are comparable with the smooth-rimmed spores of Denso- sporites and when seen in cross section would have a similar dumbbell shape. The outer surface of the spore coat is distinctly but densely ornamented with tiny puncta. When observed at magnifications less than 400 X, the puncta seem to be oriented in convolute rows and cause the crinkled ap- pearance of the spore coat. Proximo-distal compressions are not always symmetrical in outline but may be irregularly rounded tri- angular or even compressed into an oval outline if the thin proximal and distal sur- faces are missing. These spores have a size range similar to those referred to Bentzisporites bentzii Po- tonie and Kremp (1954, p. 161, pi. 20, fig. GENUS TR1LETES 49 109; 1955, pi. 7, figs. 48, 50; 1956, p. 124) from the Upper Westphalian B and Lower Westphalian C of the Ruhr Basin. Potonie (1954a, p. 115) referred these spores to the Selaginellales — herbaceous lycopods. Al- though the spores of Triletest saturnipunc- tatus apparently possess a much thicker de- velopment of the coat in the equatorial re- gion than do spores of B. bentzii, the rela- tionship of the two species may be closer than is now suspected. The spores fall within the size range of megaspores, but whether or not they func- tioned as megaspores is unknown. Their al- liance with the genus Triletes is also in question, as there is evidence neither for nor against a lycopodiaceous alliance. Occurrence. — Triletes? saturnipunctatus is common in the lower part, but rare in the upper part, of the Pope Creek Coal (macer- ations 916, 918) from Mercer County, Illi- nois, near the type locality of the Pope Creek Cyclothem. The spores have not been found yet in samples of Pope Creek Coal from other localities. Triletes? corycilis n. sp. Plate 11, figures 1-3 Description. — Megaspores trilete, origin- ally spherical or slightly elongate and sac- like, generally laterally compressed and oval in outline, from 720 to 1 350 ^ in total length (mean 11 00 /a for 10 specimens) and from 670 to 11 10 /a in width (mean 840 ti for 10 specimens) . Trilete suture well de- fined, generally open; contact areas small in proportion to total spore size with slight- ly raised arcuate ridges. Trilete rays from 110 to 270 fx in length; contact areas from 150 to 310 jx in radial dimension. Contact surfaces darker and in some specimens thicker than distal spore coat, characterized by a centrally located quadrant-shaped scar 75 to 120 fi in maximum dimension (pi. 11, fig. 3) . The contact area in some speci- mens covered by what appears to be a tri- radiate "cap" (pi. 11, fig. 2) that extends outward from spore in a ragged membra- nous ridge at the arcuate ridge and along rays (pi. 11, fig. 2) . Contact area scars not as noticeable when cap is present. Spore coat about 5 to 10^ thick, granu- lose to minutely fibrous, in some specimens appearing much darker and rough-surfaced at the distal pole; coat in area of contact surface darker, about 8 to 10^ thick. Holotype. — Maceration 798 slide 10, low- est coal in a diamond drill core from the Caseyville Group, Wabash County, Illinois (Pi. ii, % i). Discussion. — The dimensions given for the total length, and especially the width, are somewhat approximate because of the modified spore shape caused by extensive folding of the spore coat. The contact area cap is an unusual mor- phologic feature and at present its origin is not known. When it is present, the char- acteristic contact area scars generally are not noticeable. The caps could be the con- tact surfaces torn from the sister spores of a tetrad. In shape and in the possession of a some- times dark and rough distal area, the spores resemble those of Cystosporites. The coat, however, is not plainly fibrous, but can ap- pear minutely fibrous as does the coat of some spores of C. verrucosus. No abortive or immature spores of Triletes? corycilis have been recognized. These spores also resemble some of the lageniculate spores in general body outline except that they do not have an expanded apical prominence. The shape is also similar to that of some seed membranes. Although some membra- nous cuticular material bearing cell wall im- pressions was seen adhering to some speci- mens, its organic connection could not be proved. These microfossils are distinctly trilete and must have originated in a tetra- hedral tetrad. It seems unlikely that these spores are merely the inner membrane of other larger spores. At present their lycopodiaceous nature is not proved and therefore their reference to the genus Triletes is in question. Occurrence. — Megaspores of Triletes? corycilis are common in and apparently re- stricted to the oldest Pennsylvanian coals in Illinois and Indiana, the lowest coal (mac- eration 798) from a diamond drill core in Wabash County, Illinois, and the French 50 ILLINOIS STATE GEOLOGICAL SURVEY Lick Coal (maceration 151) , Orange Coun- ty, Indiana. Genus Cystosporites Schopf, 1938 Type Species. — Cystosporites breretonen- sis Schopf, by his designation. Description. — The fertile spores are large, some are up to more than 10 mm in length, oval or saclike in outline; abortive spores are smaller, circular to oval in outline. Spores of this genus are fundamentally radially symmetrical and trilete. Trilete structures are well developed, but incon- spicuous, on the fertile forms, because of their small size relative to spore size. The suture is distinct, and extends to well devel- oped arcuate ridges. Lips in many speci- mens are moderately developed and in some specimens are elongate at apex. A spongy- appearing apical cushion or tuft is present on both fertile and abortive spores of two species. Abortive spores have well devel- oped trilete structures but details of con- tact areas and sutures may be masked by folding or by the apical cushion. Ornamen- tation is variable. Spores of one species pos- sess spines; those of another have closely spaced, low, convex bumps. The spore coat is characterized by a fibrous meshlike struc- ture, generally best developed in medial portions in fertile spores where the coat is thinnest. Abortive spores generally have a thick granulose-appearing coat. Affinity. — As far as is known, this genus is inclusively correlative with the Lepido- carpaceae (Bochenski, 1936; Schopf, 1938, 1941a; Chaloner, 1952; Schopf, Wilson, and Bentall, 1944) . Occurrence. — Although one species has a long stratigraphic range, represented both in the upper Mississippian and Pennsyl- vanian, most of the other presently recog- nized species appear to be restricted to the Pennsylvanian. Dijkstra (1957) recognized one species from the Lower Carboniferous of Egypt. Cystosporites breretonensis Schopf, 1938 Plate 12, figures 9-11 1936 Triletes cf. T. giganteus Zerndt in Schopf (1936a), fig. 5 (holotype of species, by desig- nation of Schopf, 1938). 1938 Cystosporites breretonensis Schopf (in part), Cystosporites breretonensis forma reticulatus Schopf, p. 40-42; pi. 1, fig. 11; pi. 7, fig. 4. Discussion. — Spores of Cystosporites bre- retonensis apparently cannot be differenti- ated from those of C. varius on the basis of size, shape, or type of apical prominence, but only on the possession of low, convex bumps which cause an inverse reticulation on the outer surface of the spore coat. The holotype specimen is a large fertile spore showing both a spongiose apical cushion and an inverse reticulate coat in the apical region. Attached to the fertile spore are two abortive spores which also have a spongiose apical cushion and an inverse reticulate coat. The specimens illustrated (pi. 12, figs. 9a, 9b, 9c) show the same features that the holotype shows. It is important to note that fertile forms of this species possess an apical cushion, as do the fertile forms of Cystosporites varius, and that whenever fertile and abortive spec- imens are still attached, both possess inverse reticulate coats. Although this ornamenta- tion is usually developed over the entire sur- face of the abortive spores, it is usually con- fined to the proximal half, or less, of the fertile spores. Spores of C. varius, with no apparent inverse reticulation, are apt to oc- cur with those of C. breretonensis. They are not necessarily found together, nor do they necessarily occur in equal numbers when found together. In macerations 588, 580, and 520, abor- tive spores are associated with strands of spongiose material, loosely connected to the spore body only at the radial extremities and encircling the spores at the position of the arcuate ridges. Some of these spores do not have a well developed inverse reticula- tion. The spores of Cystosporites breretonensis are not easily distinguished from those of C. varius by reflected light. On spores that have an extremely well developed inverse reticulation, as do some from Carbondale coals (pi. 12, fig. 11) , the surface ornamen- tation can be distinguished by reflected light under a binocular microscope. The ornamentation is not internal but occurs on the outer spore coat surface, nor does it GENUS CYSTOSPORITES 51 seem to be intimately associated with the mesh structure of the fertile spores because the fibers of the coat run across the reticu- late pattern. Several previously published reflected light illustrations (Dijkstra, 1946, pi. 11, fig. 154; Potonie and Kremp, 1955, pi. 10, fig. 85) of spores referred to C. varius appear to be inversely reticulate. If the spores were so badly preserved or obscured by adhering materials that posi- tive identification of Cystosporites brereto- nensis was uncertain, they have been re- ferred to C. varius. In addition, the re- ported abundances are based on the com- parative abundance of spores of the two species on balsam mounts which may or may not parallel the actual relative abun- dance. Two things need to be clarified: 1) whether or not the type of Cystosporites varius possesses an inverse reticulate orna- mentation and 2) whether or not spores like those of C. varius and C. breretonensis may occur in the same cone or in cones of the same species. Occurrence. — Spores of this species are apparently absent from coals of the Casey- ville Group. They first occur in the Baby- lon Coal (maceration 588) and are rare to present in the Willis (maceration 625A- B) , Rock Island (No. 1) (macerations 626, 528A, 599B) , Murphysboro (maceration 550) , New Burnside (maceration 938C) , Bald Hill (maceration 520A) , an unnamed coal bed just above Stonefort (?) (macera- tion 554F) , and Upper DeLong (?) (mac- eration 829) Coals of the Tradewater Group. They are abundant in one sample of the Rock Island (No. 1) Coal (macera- tion 528B) . In the Carbondale Group they are com- mon to present in some samples of the Col- chester (No. 2) Coal (macerations 580, 611, 824, 825, 826) , but rare in others (macera- tions 579A-B, 603B) . They are rare in the Harrisburg (No. 5) (maceration 583) and Briar Hill (No. 5a) (maceration 633B) Coals, and present in the Herrin (No. 6) Coal (Schopf, 1938) . A few specimens were noted in the In- diana VII (?) Coal (maceration 939A) . Cystosporites varius (Wicher) Dijkstra, 1946 Plate 12, figures 5-8 1934 Sporites varius Wicher (1934a), p. 173-174; pi. 8, figs. 3, 4. 1934 Laevigati-sporites varius Wicher (1934b), p. 89-92; pi. 6, figs. 2-4, 6. 1938 Cystosporites breretonensis forma abortivus Schopf, p. 40; pi. 1, fig. 10; pi. 8, fig. 4. 1944 Cystosporites giganteus forma varius (Wich- er) Schopf, Wilson, and Bentall, p. 42. 1946 Cystosporites varius (Wicher) Dijkstra, p. 58- 59. (I differ with his interpretation of C. breretonensis as he has it in synonymy and text.) Description. — Fertile forms of Cystospo- rites varius generally smaller than those of C. giganteus, ranging from about 1000 to 4000 /x in length (Potonie and Kremp, 1956), typically elongate but well rounded proximally and distally in lateral outline. Spores characterized by an apical tuft or granulose to spongy-appearing trilobate mass which is usually wider than high. Trilete suture and contact areas obscured, except when apical tuft torn away (pi. 12, fig. 7) . Spore coat characteristically fibrous (pi. 12, fig. 8) and showing mesh structure. Abortive spores from 350-1000 p in length (Potonie and Kremp, 1956), rounded sub- triangular (pi. 12, fig. 6) to round (pi. 12, fig. 5) or elongate oval in outline. Apical tuft present. Size of tuft or cushion not constant, relative to spore-size; those on abortive spores may be the same size as those on fertile spores. Spore coat thicker than on fertile spores, generally finely granulose. Discussion. — A number of spores, noted particularly in the Willis, Tarter, and older coals, ranged from 990 to 1300^ in length. Larger spores, probably fertile, were more than 2000 ^ in length. The distinction of fertile from abortive spores on size alone seems rather tenuous. Occurrence. — The first occurrence of these spores was noted in the "Makanda" Coals (macerations 142, 906, 907) of the Caseyville Group. They were abundant in one sample. In the Tradewater Group these spores are abundant to common in the "Sub- 52 ILLINOIS STATE GEOLOGICAL SURVEY Babylon" (maceration 144) , Babylon (macerations 145B, 588) and Willis (mac- eration 625A-B) Coals. They are rare to present in the Tarter (macerations 604A, 901) and Pope Creek (macerations 602, 916) Coals, lower coal (maceration 950A) from Goose Lake, Rock Island (No. 1) Coal (macerations 626, 589, 528A-B) , Mur- physboro (macerations 550, 608), New Burn- side (maceration 938B), an unnamed coal just above the Stonefort (?) (maceration 537Q) , Wiley (maceration 525B) , and De- Koven (maceration 519B, 62 ID) Coals, in the unnamed coal (maceration 936) nine feet above the DeKoven Coal, and in an unnamed coal above the DeKoven (macera- tion 35) . They are common in the Bald Hill Coal (maceration 520A) and abun- dant in the Rock Island (No. 1) (macera- tions 929, 599A-B) and New Burnside (maceration 938C) Coals. In the Carbondale Group these spores are rare to abundant in the Colchester (No. 2) Coal (macerations 579A-B-C, 580, 582, 603B, 824, 825, 826). They are rare in the Indiana Coal IV (maceration 881) , and in one sample of the Harrisburg (No. 5) Coal (maceration 583) . They are present in the Springfield (No. 5) Coal (maceration 630) and Herrin (No. 6) (Schopf, 1938) Coal and abundant in Briar Hill (No. 5a) Coal (maceration 633A) . No spores of Cystosporites varius have been noted in coal beds of the McLeans- boro Group. Cystosporites giganteus (Zerndt) Schopf, 1938 Plate 11, figures 9, 10; plate 12, figures 1-4 1930 Triletes giganteus Zerndt (1930d), p. 71-79; pis. 9-11. 1934 Triletes giganteus Zerndt, in Zerndt, p. 13, fig. 2; pis. 1-5. 1934 Sporites giganteus (Zerndt) Wicher (1934a), p. 172-173;' pi. 8, fig. 9. 1934 Laevigati-sporites giganteus (Zerndt) Wich- er (1934b), p. 88; pi. 6, figs. 1-5. 1938 Cystosporites breretonensis Schopf (in part), p. 40-42; pi. 2, fig. 1; pi. 3, fig. 4; pi. 8, figs. 1, 2. 1944 Cystosporites giganteus (Zerndt) Schopf, 1938, in Schopf, Wilson, and Ben tall, p. 42. 1946 Cystosporites giganteus (Zerndt) Dijkstra, p. 56; pi. 12, figs. 137, 138; pi. 13, figs. 142- 145. 1955 Cystosporites giganteus (Zerndt) Schopf, in Potoni£ and Kremp, pi. 10, figs. 76-79. 1956 Cystosporites giganteus (Zerndt) Schopf, in Potonie and Kremp, p. 150-152. Description. — Fertile forms generally large, up to 11 mm in length, sac-shaped but variously folded and crumpled when compressed. Trilete structures distinct but small in relation to size of spore (pi. 11, fig. 9; pi. 12, fig. 2) . Arcuate ridges very distinct. Lips may be elongate at apex (pi. 11, fig. 10) , but not of the massive cushion type. Spore coat characteristically fibrous (pi. 12, fig. 3), usually thinnest and with best developed mesh structure medially (pi. 11, fig. 10). Abortive spores ranging from 350 to 1000^ in total dimension (Po- tonie and Kremp, 1956), usually round to oval in outline (pi. 12, fig. 1) . Trilete structures well developed, but thickness of coat and frequent radial folds mask details of contact areas and apex. Spore coat gen- erally thick and granulose. Discussion. — Both the fertile and abortive spores described by Chaloner (1954b) from the Mississippian of this country and the ones noted in the Mississippian and in some older Pennsylvanian coals in this study seem to possess a much more strongly developed apical prominence than do those in younger coals. The largest fertile spore noted in the upper Mississippian is 6210^ in length; fertde spores in younger coals are generally larger. The distinction be- tween abortive and fertile isolated spores is difficult on the basis of size alone because there seems to be a continuous size grada- tion in some coals. One example (pi. 12, fig. 4), about 1725 /x in total length, is prob- ably a fertile spore and has one abortive spore adhering to its coat and a distal ap- pendage or "stalk" such as was described by Bochenski (1936). Such spores, generally lacking distal appendages, can hardly be considered abortive, but may never have reached maturation. Complete fertile speci- mens are generally rare in any one macera- tion, probably because they were broken in transport, by induration, or in the macera- tion process. Occurrence. — The Cystosporites gigan- teus spores are present in the coals in the GENUS CYSTOSPORITES 53 Bethel (Mooretown) Formation (macera- tion 943) and Hardinsburg (maceration 810) Formation of Kentucky. They are rare in most samples of the coal in the Vienna Formation (macerations 687A, 758, 765) of Illinois, but abundant in one sample (maceration 168). They are also present in the coal in the Tar Springs Formation (maceration 760) of Illinois. A number of specimens were noted in the Upper Stony Gap Sandstone (maceration 911) of Ken- tucky. Therefore, although generally not abundant, spores of this species are com- monly present in upper Mississippian coals. The spores are rare to present in the Lick Creek Coal of the Black Creek Group and in the Upper Ream, Blue Creek, and Newcastle Coals of the Mary Lee Group of the Warrior Basin, Alabama. The spores are rare to present in all coals of the Caseyville Group, except the Battery Rock Coal (maceration 733) from Ken- tucky. They are common in older Casey- ville coals (macerations 798, 796, 795, 908) . Spores are rare to present in coals of the Tradewater Group: "Sub-Babylon" (mac- eration 144), Babylon (maceration 523 A) , Pope Creek (maceration 602) , Murphys- boro (macerations 550, 915, 628B), New Burnside (maceration 938A) , an unnamed coal bed just above the Stonefort (macera- tion 639), Wiley (maceration 525A-B) , Davis (maceration 61 8A) , DeKoven (mac- erations 619B, 621D), and in an unnamed coal bed above the DeKoven (maceration 35). In the Carbondale Group the spores are abundant in some samples of Colchester (No. 2) Coal (macerations 824, 825, 826) , and rare to present in other samples (mac- erations 603B-C, 579B-C) . The spores are rare in the Indiana Coal IV (maceration 881), abundant in Briar Hill (No. 5a) Coal (maceration 633A) , and present in Herrin (No. 6) Coal (Schopf, 1938) . They are present in the Indiana VII (?) Coal (maceration 939A) , and rare fragments of uncertain identity occur in the "West Franklin" (maceration 813b) Coal. Both of these coals are in strata equivalent to the McLeansboro Group of Illinois. Cystosporites verrucosus Dijkstra, 1946 Plate 11, figures 4-8 1946 Cystosporites? verrucosus Dijkstra, p. 60-61; pi. 15, figs. 161-166. 1955 Cystosporites verrucosus Dijkstra, in Dijkstra (1955c), p. 114-116; pi. A, figs. 1-7. Description. — Fertile megaspores saclike and more or less oval in outline, usually laterally compressed, from 1730 to 3260 ^ in length (four complete specimens meas- ured) . Apical prominence present, partly broken away on all specimens examined. Spore coat 7 to 21 p thick, composed of fibers arranged in a meshlike structure with the pores or openings in some specimens so minute that they are observable only at high magnifications (pi. 11, fig. 7), ar- ranged in folds radiating from the apical region and extending half or less the length of the spore (pi. 11, fig. 5) . Spore coat set with small, bunt to sharply pointed spines 25 to 85 fx in length and 20 to 40 ^ in diam- eter across the base which may be bulbose (pi. 11, figs. 7, 8) . Spines most densely set in the apical region, widely spaced distally. Converging spinose folds defining the arcu- ate ridges, demarcating the distal surface from the smooth, frequently folded contact areas. Some complete fertile specimens possessing a distal appendage (pi. 11, figs. 4, 5) , composed of a more or less homo- geneous granular material, which is gener- ally readily separable from the megaspore body. Isolated abortive megaspores (pi. 11, fig. 6) more or less spherical, tending to an oblate shape in lateral compressions, circu- lar in proximo-distal compressions, up to 410 fx in length (excluding apical promi- nence) and ranging from 320 to 515^ in equatorial diameter. Apical prominence spatula-like in shape, up to 307 ^ in height. Apical prominence and contact areas more or less unornamented. Spore coat densely fibrous to granulose, 15 /x thick on one specimen, set with spines 20 to 40 ^ in length and 10 to 20 ^ in diameter. Abortive spores still attached to fertile megaspores generally smaller, possessing a less spinose or nonspinose coat, 54 ILLINOIS STATE GEOLOGICAL SURVEY Discussion. — The above description of the fertile and abortive megaspores found in Illinois coals agrees remarkably well with that recently given by Dijkstra (1955c). His paper should be consulted for the listing of synonyms, discussion of the various aspects of spore morphology, and his reasons for interpreting this species as a species of Cystosporites. The granulater material adhering to the distal portion of the fertile megaspores is considered by Dijkstra (1955c), Chaloner (1954a), and Arnold (1950) as analogous to the "wing-like appendage" or "stalk" de- scribed by Bochenski (1936) as attaching the fertile megaspore (Cystosporites gigan- teus-type) to the adaxial wall of the spo- rangium of Lepidostrobus major. A similar mode of attachment was noted by Chaloner (1954a) in the sporangia of L. monospora. In this study I noted not only the common occurrence of this appendage on fertile spores of C. verrucosus but also its occur- rence on several specimens referable to C. giganteus. The spore coat of an individual fertile megaspore of Cystosporites verrucosus may vary from a dense fibrous mesh, having gross fibers and small interstices, to a granu- lose-appearing coat. The mesh is most dense or the coat most granulose in the api- cal region. Coats of the abortive spores ap- pear granulose. Coats with the very dense mesh structure (pi. 11, fig. 8), bear a marked resemblance to the coats of some lagenicu- late spores. Dijkstra (1955c) found, as I have, that the fertile spores of Cystosporites verru- cosus possess a fibrous coat, at least in the central region of the saclike spore body. This fibrous type of coat is a characteristic feature of the genus Cystosporites (Schopf, Wilson, and Bentall, 1944, p. 41). In the original descriptions of Lagenicula saccata Arnold, 1950, and of the spores Lepidostro- bus monospora Chaloner, 1954, the spore coats were described as granular. However, as Dijkstra (1955c) pointed out, high mag- nification study by transmitted light is usually necessary to distinguish the fibrous nature of the spore coat of C. verrucosus. In Dijkstra's opinion the spores of Lepi- dostrobus braidwoodensis Arnold, 1938, and Lepidostrobus monospora Chaloner 1954, and Lagenicula saccata Arnold, 1950, are all comparable to Cystosporites. Cystosporites verrucosus and C. verruco- sus-type spores have been reported (Dijk- stra, 1955c) from Belgium, Netherlands- Westphalian A, B; Great Britain - West- phalian B (Lepidostrobus monospora) ; Spain - Westphalian A; U.S.A. (Michi- gan) - Westphalian A, B; U. S. A. (Illi- nois) - shale above Colchester (No. 2) Coal, lower Carbondale - Westphalian D? (L. braidwoodensis) . The spores of this species are not very abundant in Illinois coals but their frag- ments are readily identifiable because of the characteristically folded, dense- ly meshed spinose coat. Occurrence. — Spores of this species are rare in the "Makanda" Coals (macerations 905, 907) , present in the Pope Creek Coal (maceration 916), rare to common in the Colchester (No. 2) Coal (macerations 824, 825, 826) , and present in the Indiana Coal IV (maceration 881) . Thus, Cystosporites verrucosus is represented by sporadic occur- rences in coals of the Caseyville, Trade- water, and Carbondale Groups. Genus Spencerisporites Chaloner, 1951 Type species. — Spencerisporites radiatus (Ibrahim) n. comb. [Spencerisporites karczewskii (/emdt, 1934, pi. XXXI, fig. 3) Chaloner, 1951], by designation of Chaloner, 1951, p. 862. Discussion. — The spores of Spencerispo- rites, although small (generally 300 to 400 n) for "large" spores, have a distinctive as- pect. The more or less spherical spore body is encircled at the equator by a bladder which is subtriangular or deltoid-shaped in proximo-distal outline and possesses a mar- ginal frill or flange. The spores commonly have strongly developed trilete rays and some are characteristically ornamented with radial striations on the contact areas. The correct generic designation for these spores, found isolated, is somewhat in question. Similar spores were first described from a lycopod cone designated as Lepido- strobus by Williamson (1879, 1894) which Scott (1898) later redescribed and desig- GENUS SPENCERISPORITES 55 nated as Spencerites. Similar but isolated spores were described by Kubart (1910) as S. membranaceus, an incorrect generic des- ignation according to the present Inter- national Code of Botanical Nomenclature. Ibrahim (1932) described spores which he designated as Sporonites radiatus, later designated as Zonales-sporites radiatus Ibra- him by Ibrahim (1933) and by Loose (1934)! Zerndt in 1934 described similar spores as Triletes karczewskii. The spores of the two species are appar- ently identical. Horst (1955, p. 193) stated that Zerndt himself was of this opinion. Dijkstra (1955a, p. 343) stated, "As there exists no doubt that Microsporites kar- czewskii and Triletes radiatus (Ibrahim) Schopf, Wilson, and Bentall are identical, the name karczewskii must be changed into radiatus." Later Zerndt (1937b) described spores somewhat similar to, but distinguishable from, those of Ibrahim's Sporonites radia- tus from the Westphalian E of Bohemia and designated them as Triletes gracilis. Schopf, Wilson, and Bentall (1944) recog- nized three species which they felt were referable to three separate genera: T. radi- atus (Ibrahim) Schopf, Wilson, and Ben- tall, Endosporites? karczewskii (Zerndt) Schopf, Wilson, and Bentall, and Cirratri- raditesf gracilis (Zerndt) Schopf, Wilson, and Bentall. Dijkstra (1946) recognized two species of Microsporites, used as a generic term but not diagnosed as such: M. karczewskii (Zerndt) Dijkstra, and M . gracilis (Zerndt) Dijkstra. The author himself (Dijkstra, 1955a) later rejected the name Micro- sporites in favor of a questionable referral to Endosporites [E.f radiatus (Ibrahim) Dijkstra] as Schopf, Wilson, and Bentall (1944) had done previously in E.f kar- czewskii. Because the author (Dijkstra, 1955a, 1957) has rejected Microsporites, it cannot be considered a valid generic designation (International Code, Article 33, see Lan- jouw) , although Potonie and Kremp (1954, 1956) and Horst (1955) consider it as such. In 1951 Chaloner fully described the spores of Spencerites insignis Scott, and similar but isolated spores which Chaloner referred to Spencerisporites karczewskii (Zerndt) Chaloner. Potonie and Kremp (1954, 1956) rejected this generic name on the basis of the priority of Microsporites Dijkstra (which Dijkstra has rejected, as noted above) and stated that although nei- ther Dijkstra (1946) nor Chaloner (1951) presented generic diagnoses, their intent was the same and was clear from their spe- cific descriptions. Unlike Dijkstra, Chalo- ner (1951, p. 861-862) did present a clearly indicated generic diagnosis. Dijkstra (1955a, p. 343) rejected the name Spenceri- sporites on the basis of recommendations made at the 1951 Heerlen Congress. These recommendations have no standing as re- gards the International Code of Botanical Nomenclature and cannot be considered as a basis for rejecting the name Spencerispo- rites. Because, in my opinion, these spores are not closely related to Triletes, Endospor- ites, or Cirratriradites, because all certainly should be referred to the same genus, and in view of the above comments, it seems that Spencerisporites Chaloner is the only correct generic designation. Chaloner (1951, p. 862) designated Zerndt's (1934, pi. XXXI, fig. 3) specimen as the holotype of S. karczewskii which in turn is the type of Spencerisporites. Although Zerndt's speci- men can be regarded as the holotype, his specific epithet is a later synonym of Ibra- him's in Sporonites radiatus, so that the holotype is correctly referred to Spenceri- sporites radiatus (Ibrahim) n. comb. Potonie and Kremp (1956) recognized four species which are: Microsporites gra- cilis (Zerndt) Dijkstra, M. karczewskii (Zerndt) Dijkstra, M. (Spencerites) mem- branaceus (Kubart) n. comb., M. radiatus (Ibrahim) Dijkstra (Potonie and Kremp [1956], not Dijkstra, are responsible for this combination) . I have been able to recog- nize only two distinct forms of spores of Spencerisporites from Illinois coals. These are referred to 5. cf. S. radiatus (Ibrahim) n. comb, and S. cf. S. gracilis (Zerndt) n. comb. Detailed descriptions of these spores are given in an effort to shed some light on 56 ILLINOIS STATE GEOLOGICAL SURVEY the morphological changes and intergrada- tions between spores of the two species with the passage of time. Although only 52 measured specimens are reported below, many more observations and spot-check measurements were made during the course of this study. Dijkstra (1955b, p. 7) stated that Cross (1947) reported Triletes radiatus (Ibra- him) Schopf, Wilson, and Bentall in coals of the Appalachian Basin. From Cross' (1947, p. 301) description it is more likely that Cross was referring to T. radiatus as described by Zerndt (1937a) (T. radiosus Schopf, Wilson, and Bentall) and not to T. radiatus (Ibrahim) Schopf, Wilson, and Bentall. Cross (1947, fig. 2, p. 287) did, however, report the occurrence of Cirratri- radites gracilis in the Cedar Grove, Chilton, Winifrede, and Coalburg Coals from the upper part of the Kanawha Group (Potts- ville Series) and from the No. 5 Block Coal from the lower part of the Allegheny Series. Schopf (1949) noted, in his discussion of bladdered spores of this type, the occur- rence of spores similar to those of C. (?) gracilis Schopf, Wilson, and Bentall in some upper Pennsylvanian coals in Illinois. He also questioned Dijkstra's (1946) sug- gestion that this species and Ibrahim's Sporonites radiatus are closely related. Although seemingly most abundant in older coals of the Caseyville Group of Illi- nois, some spores of Spencerisporites occur sporadically in coals of the Tradewater, Carbondale, and McLeansboro Groups. Those younger coals in which Spenceri- sporites is fairly commonly represented are the Willis Coal, DeKoven Coal, No. 5 Coal, and a few of the coals in the McLeansboro Group. No spores of Spencerisporites were noted in the Warrior Basin coals examined or in coals of upper Mississippian age. Spencerisporites radiatus (Ibrahim) n. comb. 1932 Sporonites radiatus Ibrahim, in Potonie, Ibrahim, and Loose, p. 449; pi. 16, fig. 25. 1933 Zonal es-sporites radiatus (Ibrahim) Ibrahim, p. 28-29; pi. 3, fig. 25. 1934 Triletes karczewskii Zerndt, p. 27; pi. XXXI, fig. 3. 1944 Triletes radiatus (Ibrahim) Schopf, Wilson, and Bentall, p. 24. 1944 Endosporites (?) karczewskii (Zerndt) Schopf, Wilson, and Bentall, p. 45-46. 1946 Microsporites karczewskii (Zerndt) Dijkstra, p. 64, pi. 4, fig. 40. 1951 Spencerisporites karczewskii (Zerndt) Chalo- ner, p. 862; figs. 1, 2, 6, 7. 1955 Endosporites (?) radiatus (Ibrahim) Dijkstra (1955a), p. 314-316, 342-343; pi. XLV, fig. 54. 1955 Microsporites radiatus (Ibrahim) Potonie and Kremp, in Horst, p. 192-194; pi. 18, fig. 15; pi. 19, fig. 16. 1956 Microsporites radiatus (Ibrahim) Dijkstra, in Potonie and Kremp, p. 157-158; pi. 20, figs. 449, 450. Spencerisporites cf. S. radiatus (Ibrahim) Plate 13, figures 1-6 Description. — Spores trilete, commonly in proximo-distal compressions, character- ized by a more or less circular body cavity (in proximal view) which is encircled equatorially by an inflated bladder (pi. 13, fig. 2) . Bladder triangular to subtriangular in proximo-distal outline, more or less disk- shaped transversely, widest at opposite ends of trilete rays, and possessing a marginal flange. Total diameter of spores, including bladder and marginal flange, from 272 to 412 fx (mean 354^ for 27 specimens) . On any one spore, one diameter, taken from corner to opposite midpoint of interradial margin, seemingly longer than the other two diameters. Marginal flange from less than 15 to 40 ^ wide at corners of bladder and less than 10 to 29 /x wide interradially. Total flange width, measured on both sides of specimen, averaging 10.5 percent of the total spore diameter. On several specimens, upper and lower surfaces of bladder at equatorial attachment area appear to be 30 ii apart at the juncture of the trilete rays and bladder, but only 15 /x apart at the interradial margin. Trilete rays generally prominent. Lips thin, membranous, sometimes split apart (pi. 13, fig. 1), straight to sinuous, up to 36 /jl in height, sometimes expressed as thin folds extending from the inner bladder margin to outer margin of flange (pi. 13, figs. 4, 5a) . Each contact area invariably ornamented writh distinct, fine, sometimes broken lines or striations radiating gener- GENUS SPENCERISPORITES 57 ally from a central area on the contact sur- face. Radial striations sometimes appearing as coarse gouges (pi. 13, fig. 3) , as opposed to more delicate sinuous striations as shown by figure 5b on plate 13. Distal side of spore body and, in some specimens, distal surface of bladder appear smooth. Proximal surface of bladder and marginal flange ornamented with vague in- tersecting or anastomosing fine folds. Spores golden to brownish yellow cen- trally, generally very light yellow at flange by transmitted light. Discussion. — In most details of spore morphology these spores, although some- what larger, agree with those of Spenceri- sporites karczewskii and of Spencer ites in- signis as described by Chaloner (1951) . On one specimen the distal spore body coat is twice as thick (4 y) as the thickness given by Chaloner. Measurements of the diame- ter of the spore body, or body cavity, are not given here because it is not measurable with accuracy on compressed specimens. The compressed specimens studied agree with Chaloner's interpretation that the marginal flange is a single membrane (al- though Potonie and Kremp [1956] regarded it as two membranes) contiguous with the upper surface of the bladder. The radial striations on each contact face do not all radiate from a common point in the center. More or less parallel lines extend nearly through the center of each contact face from the corners of the spore body. The lines, both towards the apex and towards the margin of the spore body, become more and more flexed near their midpoints (pi. 13, fig. 5b) . The gen- eral aspect is of slightly superimposed finger-prints on each contact area, and al- though on some specimens (pi. 13, fig. 3) the lines appear straight and as gouges, the pattern is more or less the same. These lines also appear to extend slightly onto the bladder but end at the base of the lips. Spores of two slightly different aspects are included in this species because inter- grading or transitional forms are numerous, and any distinction, at present, would have to be based on arbitrary numerical values, for example, for width of the marginal flange. Those spores of the lowest coal in a diamond drill core in the Caseyville Group (pi. 13, fig. 3) in Wabash County, Illinois, generally have a narrow marginal flange that accounts for 10 percent or less of the total diameter, and some specimens possess a flange so narrow that it is barely notice- able. The intersecting lines on the bladder generally are vague. The trilete rays in some specimens are expressed as folds on the bladder. They are similar to those illus- trated by Horst (1955, pi. 18, fig. 15; pi. 19, fig. 16) from the Hruschau zone of the Na- murian A in the Mahrische-Ostrau region. Smaller but seeminglv related spores re- ported by Dijkstra (1957) as Endosporites chaloneri occur in the coal beds of the Limestone Coal Group of Scotland. In con- tradistinction, those found in the Reynolds- burg Coal appear to have a generally wider marginal flange accounting for up to 18 percent of the total diameter. A more con- spicuous ornamentation appears on the bladder, in some cases even apiculations, and the rays are more commonly expressed as folds on the bladder. The spores of this species are distinguish- able from those of Spencerisporites cf. S. gracilis by the presence of radial striations on the contact areas and by a generally narrower marginal flange. Previously reported occurrences of spores referable to Spencerisporites radiatus are given in Diikstra (1946) and Potonie and Kremp (1956). In general this species is represented in the Namurian A, B?, and C? and in the Westphalian A, B, C, and D?. Occurrence.— These spores are most abundant, even occurring in masses, in the lowest coal in a diamond drill core (macer- ation 798) of two Wabash County cores, but are rare in two of the upper coals (mac- erations 795, 797) of these two cores. They are rare in one sample of the Battery Rock Coal (maceration 587) , but are present in another sample (maceration 629) . They also are present in the "Makanda" Coals (macerations 905, 906) and very abundant in the Reynoldsburg Coal (maceration 618) . They are rare in the shale above the Pinnick Coal (maceration 163) and in the 58 // LINOIS STATE GEOLOGICAL SUR) EY Cannelton Coal (maceration 780) from In- diana. These spores, therefore, are a fairly common constituent in the maceration residues of coals in the Caseyville Group. \ lew specimens are found in the Tarter Coal (macerations 604A, 901, 914), in the Willis (?) Coal (maceration 631), and in the lower pan of the Willis Coal (macera- tion 625B) . Specimens are rarely present in one sample of the Rock Island (No. 1) Coal (mac caal ion 599A) . Spencerisporites gracilis (Zerndt) n. comb. 1937 Triletes gracilis Zerndt (1937b), p. 586-587: pi. 10, figs. 1-10. 1914 Cirratriradites (?) gracilis (Zerndt) Schopf, Wilson, and Bentall, p. 44. 1946 Microsporites gracilis (Zerndt) Dijkstra, p. 64-65. Spencerisporites cf. S. gracilis (Zerndt) Plate 13, figures 7-9 Description. — Spores of Spencerisporites cf. S. gracilis similar to those of S. cf. S. ra- diatus in general body form, bladder de- velopment, and compressional orientation. Total diameter of spores, indudirg bladder and marginal flange, from 278 to 468 ^ (mean 378 ^ for 25 specimens) . Marginal flange accounting for 10 to 28 percent (mean 19.4 percent) of the total diameter. Flange width from 25 to 65 ^ at corners of bladder and from 15 to 65^ interradially. More than three-fourths of the spores have a flange width of more than 40 p. Trilete rays distinct, lips open in many specimens, membranous, in some speci- mens expressed as thin folds on bladder (pi. 13, fig. 9). Contact areas apparently not marked by radial striatums, in some instances showing an anastomosing network of folds similar to those developed on dis- tal areas of central spore body. Bladder ornamented with vague anastomosing folds, in some specimens appearing radially pleated and finely apiculate. Marginal flange in some specimens almost smooth, pleated, or ornamented with vague inter- secting lines; flange generally crenulate or scalloped at outer margin and in some in- stances clearly demarcated from the outer margin of the bladder (pi. 13, fig. 8) . Spore coal generally light yellow, central portion slightly darker by transmitted light. Discussion. — These spores are very simi- lar in appearance to those originally illus- trated and described by Zerndt (1937b, p. 586-587, pi. 12) as Triletes gracilis, especial- l\ id the development of a wide marginal flange ("der ausserste Sporensaum" of Zerndt, 1937b, p. 587). Zerndt refers to small ear-like flaps on the corners, about 96 fx wide and 48^ long. This feature is often cited as characteristic of these spores, but it is not clearly described or illustrated. Zerndt may have been referring to the lobe-like aspect of the outer margin of the bladder or the outer margin of the mar- ginal flange (as shown in his figure 8 on plate 12, at the upper righthand corner). The spores described here may appear to have a lobe-like outline at the outer mar- gin of the marginal flange at two of three corners (pi. 13, fig. 9), but this is caused by slight folds along the margin. Because the position of the ear-like lobes is not at all clear from Zerndt's description or illus- trations, I cannot compare adequately these Illinois spores to those originally described as T. gracilis by Zerndt, and have, there- fore, referred to them as Spencerisporites cf. S. gracilis. In comparison to those of Spencerispor- ites cf. S. radiatus, these spores have a much lighter colored central area, the proximal and distal surfaces of which usually bear anastomosing folds (pi. 1 3, fig. 8) . The con- tact areas have no clearly defined radial striations and some even lack the anasto- mosing folds. The marginal rim is, with few exceptions, much wider relative to total spore size and is not as highly orna- mented with anastomosing folds as are spores of S. cf. 5. radiatus (pi. 13, fig. 6). The marginal flange may be smooth and may be scalloped at the edge. The change from the type of flange of early Pennsylvanian age (pi. 13, fig. 1) to the type of late Pennsylvanian age (pi. 13, fig. 9) is rather gradual and no definite de- lineation between spores of Spencerispor- ites cf. .S'. radiatus and S. cf. S. gracilis can be made on the basis of flange width alone. GENUS CALAMOSPORA 59 However, none of the specimens here re- ferred to S. cf. S. gracilis possesses radially striated contact surfaces. Such surfaces are shown only by spores found in the Rock Island (No. 1) Coal and older coals whereas those with anastomosing folds rather than radial striations on the contact areas are found only in younger coals. The marginal flange on spores of the Reynoldsburg Coal (maceration 618) ac- counts for 9 to 18 percent (mean 13.5 per- cent) of the total diameter; the same spores have well defined contact area striations. The marginal flange on spores from the DeKoven Coal (maceration 519A-B) ac- counts for 11 to 19 percent (mean 15.7 percent) of the total diameter. None of these spores has contact area striations. On spores from some of the McLeansboro coals the marginal flange accounts for 10 to 28 percent (mean 21 percent) of the total diameter. The spores to which these Illinois spores are compared were originally described by Zerndt (1937b) from the Westphalian E (Stephanian) of Bohemia. Occurrence. — This species is represented in the Wiley (maceration 525A) , Davis (maceration 518B), and DeKoven (macer- ation 519A-B) Coals from the upper part of the Tradewater Group. These spores are fairly common in the lower part of the De- Koven Coal. In the Carbondale Group the spores are rare in the Colchester (No. 2) Coal (maceration 580) , rare to common in the No. 5 Coal (macerations 630, 879, re- spectively) , and present in the Briar Hill (No. 5a) Coal (maceration 633A) . In the McLeansboro Group spores of this species are rare in a Friendsville Coal (maceration 490D) , in the "LaSalle" Coal (maceration 600) , and in a coal bed desig- nated as the "Divide" Coal (maceration 811). In the Illinois State Geological Sur- vey maceration records, their presence has been noted in coal beds designated as "Bo- gota," "Newton," Shelbyville, and Trow- bridge, mainly from Effingham, Fayette, and Shelby Counties, Illinois. Many of these have been checked as to their identity with Spencerisporites cf. S. gracilis. They are common to abundant and well pre- served in the "Bogota" Coal (maceration 133), an upper McLeansboro coal in Illinois. Genus Calamospora Schopf, Wilson, and Bentall, 1944 Type species. — Calamospora hartungiana Schopf, in Schopf, Wilson, and Bentall, 1944, by their designation. Description. — Spores of Calamospora are trilete and radially symmetrical. Their original shape is more or less spherical, so that when compressed, they develop char- acteristic taper-point folds of crescentic or lenticular outline. Spore size may range from 30 to several hundred microns. Horst (1955) extended the upper size limit to more than 1000 p. Trilete rays are generally short, less than one-half the spore radius in length. Lips may be present. Contact areas may show some differentiation of the spore coat in surface texture or thickening. Spore coat thickness ranges from more than 15 /x in spores larger than 500 p in diameter to less than 2 p in those less than 100 jX in di- ameter. The coat is characteristically smooth and highly refractive. Discussion. — Only the larger spores of Calamospora, undoubtedly megaspores, are described in this paper. The smaller mega- spores appear to have a long stratigraphic range, occurring throughout the Pennsyl- vanian in Illinois; the large megaspores (C. cf. C. sinuosa) seem to be restricted to older coal beds of the Tradewater Group. Affinity. — These spores are of sphenopsid alliance and may be borne by plants of the Sphenophyllales, Equisetales, and Noegge- rathiales. Calamospora is unique among taxa based on spores, in that isospores, mi- crospores, and megaspores are included within it. Occurrence. — Only one poorly preserved megaspore, questionably referable to Cala- mospora, was found in coals of upper Mis- sissippian age. Megaspores referred to C. laevigata are present in many of the Penn- sylvanian coals; those referred to C. sinuosa occur only in the older coals of the Trade- water Group. In addition, a few specimens, indeterminable on the specific level, were found in the Rock Island (No. 1) Coal 60 ILLINOIS STATE GEOLOGICAL SURVEY (maceration 599B) and in the DeKoven (?) Coal (maceration 554D) . Calamospora megaspores are also present in the Jagger, Blue Creek, and Newcastle Coals of the Mary Lee Group in the Warrior Basin of Alabama. Calamospora sinuosa (Potonie and Kremp) ex Horst, 1955 1955 Calamospora (Triletes) sinuosa (Horst, 1943, fig. 3) Potoni6 and Kremp, p. 48 (nom. nudum). 1955 Calamospora sinuosa (Horst) Potonie and Kremp, in Horst, p. 155-156; pi. 17, fig. 3. Calamospora cf. C. sinuosa Plate 13, figure 10 Description. — Spores large, originally nearly spherical, developing many taper- point folds upon compression. Maximum diameter ranging from 610 to 1020 ^ (mean 804 p for 17 measured specimens). Trilete rays one-third to one-half the spore radius in length with lips up to 20 ^ in height. Trilete mark usually incorporated into taper-point folds. Contact areas not differ- entiated by spore coat thickening or change in spore coat texture. Spore coat ranging from 6 to 13 /x in thickness, golden yellow to brownish yellow by transmitted light, glossy by reflected light. Discussion. — These spores are of the same size as those described by Horst (1955) but may have slightly higher lips and apparently do not show the infra- granulate texture of the contact area de- scribed by him. Horst's (1955) suggestion that the spores described as Sporites plica- tus by Schopf (1938) could be referable to Calamospora sinuosa is untenable. Similar megaspores are described by Arnold (1944) from a sphenophyllaceous fructification, Bowmanites delectus, found in a shale be- low Cycle "A" at Grand Ledge, Michigan. The larger spores range from 660 to 750 ^ in maximum diameter and some of the abortive spores are one-third this size. Those illustrated by Arnold (1944, figs. 4, 7) appear very similar to the one shown by figure 10 on plate 13. Horst (1955) originally described this species from the Namurian A of Mahrisch- Ostrau and west Upper Silesia. Occurrence. — These spores are common to present in the Willis Coal (macerations 625 A-B, 631) and rare in the Tarter (mac- eration 604A) and Babylon (maceration 523 A) Coals of the Tradewater Group. Calamospora laevigata (Ibrahim) Schopf, Wilson, and Bentall, 1944 1933 Laevigati-sporites laevigatus Ibrahim, p. 17; pi. 6, fig. 46. 1934 Laevigati-sporites laevigatus Ibrahim, in Loose, p. 146; pi. 7, fig. 36. 1934 (Calamitif)-sporites laevigatus Ibrahim, in Wicher (1934a), p. 172. 1944 Calamospora laevigatus (Ibrahim) Schopf, Wilson, and Bentall, p. 52. Calamospora cf. C. laevigata Plate 13, figure 11 Description. — Spores originally more or less spherical, when compressed developing characteristic taper-point folds, maximum diameter ranging from 270 to 445 p (mean 336 ii for 19 specimens) . Trilete rays short, ranging in length from 15 to 30 percent of the spore radius. Labial development usu- ally not obvious. Contact areas sometimes appearing punctate (pi. 13, fig. 11). Spore coat ranging from 2 to 10^ in thickness, thicker and darker at contact areas, golden yellow by transmitted light. Discussion. — These spores, which may represent several different plants, at pres- ent seem to lack distinguishable features. They may not properly be referable to C. laevigata, because Potonie and Kremp (1955) stated that there is no contact area differentiation on spores of this species. The size range of the Illinois spores is iden- tical to that given by both Potonie and Kremp (1955) and by Horst (1955) . How- ever, the coat thickness of the Illinois spores ranges from less than to greater than the limits given by these authors. Horst (1955) recorded Calamospora laevigata from the Namurian A of the Mahrisch-Ostrau region and from the West- phalian A of the west Upper Silesian re- gion. Potonie and Kremp (1955) recorded this species from the Upper Westphalian B of the Ruhr Basin. Occurrence. — These spores are present to rare in Caseyville coals (macerations 795, GENUS MONOLETES 61 796, 797, 908) . They also are present to rare in the following Tradewater coals: Babylon (maceration 588) , Tarter (macer- ation 901), Rock Island (No. 1) (macera- tion 929), Bald Hill (maceration 520A) and an unnamed coal above DeKoven (maceration 35) . In the Carbondale Group they are generally present in the Colchester (No. 2) Coal (macerations 611, 579C, 603B-C, 826, 582), in the Summum (No. 4) Coal (maceration 463) , and in the Grape Creek (No. 6) Coal (maceration 878) . Spores of this species are rare in the Indi- ana IV (maceration 881) and Springfield (No. 5) (maceration 630) Coals, but seem to be common in the Briar Hill (No. 5a) Coal (maceration 633A) . In the McLeans- boro Group they are present in the Indiana VII (?) Coal (maceration 939A) , the "Bo- gota" (maceration 133), and "Woodbury" (maceration 703) Coals; common in the Friendsville Coal (maceration 490D) ; abundant in the "LaSalle" (maceration 600) and Friendsville (?) (maceration 136) Coals. Calamospora sp. Plate 13, figure 12 This spore is 185^ in diameter, much smaller than the spores of Calamospora cf. C. laevigata with which it occurs. The spore coat is extremely thick in relation to spore size, especially at the contact area. This single example wras found in the "La- Salle" Coal (maceration 600) of the McLeansboro Group. Genus Monoletes (Ibrahim) Schopf, Wilson, and Bentall, 1944 Type species. — Monoletes ovatus Schopf, by desig- nation of Schopf, Wilson, and Bentall, 1944. Description. — Prepollen of Monoletes appear bilateral and monolete although they are asymmetrically bilateral in that the suture deviates from a straight line and exhibits a characteristic angular deflection medially. Occasionally what may be a short vestigial ray is observed at the point of de- flection. Schopf, Wilson, and Bentall (1944) noted that the prepollen may have originated in tetrahedral tetrads. Com- pressed specimens are nearly circular to rounded lenticular in outline, ranging from slightly more than 100 ^ to more than 500 p in length. The distal surface on ex- panded prepollen is often marked by two longitudinal grooves separated by a well rounded umbo. Compressed examples usu- ally have longitudinal folds parallel to the distal grooves. The coat is minutely granu- lose, up to 18/x thick proximally and dis- tally, sometimes less than 5 ^ thick at the base of the distal grooves. An inner mem- brane is frequently present. More complete discussions of the morphology of Monoletes prepollen were given by Schopf (1938) , Schopf, Wilson, and Bentall (1944), and Schopf (1948). Discussion. — Schopf, Wilson, and Ben- tall (1944) pointed out that the two recog- nized species, Monoletes ovatus Schopf and M. ellipsoides (Ibrahim) Schopf, are wide- ly distributed and must still be regarded as rather generalized types. Prepollen of these two species were distinguished by Schopl (1938) on the basis of published descrip- tions and illustrations available at that time which indicated that M. ellipsoides lacked distal grooves. It now appears, with the illustration of the type of M. ellipsoides by Potonie and Kremp (1956, pi. 22, fig. 478) that these spores also possess distal grooves. It would seem that morphological features of prepollen of the two species overlap to a considerable degree. Potonie and Kremp (1956) recognized Monoletes aureolus Schopf as a species of Schopfipollenites, a synonym of Monoletes, but Schopf, Wilson, and Bentall (1944) referred this species to Zonalo-sporites Ibrahim. This prepollen is similar to that of Monoletes but appears to have a thin outer coat and thick inner coat. The specimens illustrated on plate 14, figures 1 to 9, show some of the natural, compressional, and preservational varia- tions in aspect of isolated, compressed Monoletes prepollen. At present there is no advantage to referring these to either of the two widely cited species, although some could readily be referred to M. ovatus Schopf. 62 ILLINOIS STATE GEOLOGICAL SURVEY Affinity. — These prepollen grains are pteridospermic and probably largely co- extensive with the Medullosaceae (Schopf, Wilson, and Bentall, 1944) . Some may lack distal grooves, as do those of Codonotheca (Schopf, 1948) , but all seem to be charac- terized by a medially deflected suture. Occurrence. — According to Dijkstra (1955a), this prepollen is found in the Westphalian and Stephanian of European coal basins. MONOLETES Spp. Plate 14, figures 1-10 Discussion. — Very few specimens of Monoletes were noted to lack the distal longitudinal folds as are typically shown by figures 6 and 9 on plate 14. Many speci- mens (pi. 14, fig. 8) from the "West Frank- lin" Coal exhibit long thin folds of the coat, but these generally are variously dis- posed relative to the long axis. All ex- amples observed have a medially deflected suture and some appear to possess a third ray (pi. 14, figs. 5, 7, 9) . The third ray shown by figure 5 on plate 10 is 26^ in length. One of the smallest prepollen, and also one of the oldest specimens, is 200 ^ in length (pi. 14, fig. 1) ; one of the more robust specimens is more than 500 ^ in length (pi. 14, fig. 6) . In a few prepollen grains of many differ- ent samples of coal, the inner membrane is observed to be pulled away from the outer coat (pi. 14, figs. 1, 3, 4, 7) . In any one prepollen mass where most specimens ap- pear "normal," one or two may have "shrunken" inner membranes. The speci- men illustrated by figure 7 on plate 14 is similar to those originally described as Monoletes aureolus by Schopf (1938). Al- though the inner body of this specimen is very dark — the negative of this illustration required extensive dodging in order to show central detail — the inner coat is only 6 ^ thick, a few microns thicker than the inner coat of the holotype of M. aureolus. The outer coat, poorly preserved, appears very thin, but is actually about 20 /x thick around the margin. The holotype of M. aureolus also appears to have an outer coat of similar thickness. Although the pre- pollen may represent a distinct species of Monoletes, it also is possible that it repre- sents "sports" of prepollen which, if nor- mally developed, might be referred to M. ovatus. Such "sports" of Spencerisporites also possess much smaller and darker cen- tral bodies than do the majority of spores of Spencerisporites. Monoletes prepollen often occurs in masses, as that shown in figure 10 on plate 14, from the "Divide" Coal in which Mono- letes is abundantly represented. The pre- pollen is very glossy under reflected light. Occurrence. — Monoletes is not repre- sented in upper Mississippian coals. No prepollen was observed in the coals of the Black Creek, Mary Lee, or Pratt Groups from the Warrior Basin of Alabama, al- though resin rodlets, of medullosan origin and in many instances associated with Monoletes prepollen, were present in some of the coal beds of the Black Creek and Mary Lee Groups. Monoletes is commonly represented in two coals (macerations 795, 910) and sparsely represented in other coals of the Caseyville Group. The prepollen is first abundant in the Babylon Coal (maceration 588) . It is also abundant in one sample of the Rock Island (No. 1) Coal (maceration 528B) and in two Tradewater coals (mac- eration 950, 95 IB) from Goose Lake, Illinois. Monoletes prepollen is generally present to common in most coals of the Tradewater Group and may be abundant in the Col- chester (No. 2) , No. 5, Briar Hill (No. 5a) , and Herrin (No. 6) Coals of the Car- bondale Group. In the McLeansboro Group, prepollen is common in the Indiana VII (?) Coal (maceration 939A) and the "West Franklin" Coal (maceration 831) ; abundant in the Friendsville Coal (macera- tions 153, 135, and 490D) , the "Divide" Coal (maceration 811); present in the "LaSalle" Coal (maceration 600) , the "Bo- gota" Coal (maceration 133), and the "Woodbury" Coal (maceration 703) ; rare in the Friendsville (?) Coal (maceration 136) . Monoletes is also known from the GENUS PUNCTATISPORITES 63 Danville (No. 7) , Macoupin, and Flanni- gan Coals. Very few samples of Tradewater or younger coals lack M oriole tes prepollen. Genus Parasporites Schopf, 1938 Type species. — Parasporites maccabei Schopf, 1938, by monotypv. Description. — These prepollen grains are characterized by opposite and distally dis- posed bladders, appearing bilaterally sym- metrical. Fundamentally they are radially symmetrical and possess a proximal trilete mark. Two of the rays, extending more or less towards the lateral bladders, may be well developed; the third ray is shorter than the other two and commonly indis- tinct. The over-all dimension as given by Schopf (1938) and Schopf, Wilson, and Bentall (1944) is as much as 300 p. The spore body is round to oval. The body wall is relatively thicker than the bladder mem- brane, which extends completely around the body but is expanded into bladders only laterally and may be rugose. Affinity. — The affinity of these prepollen grains is still in question. Schopf, Wilson, and Bentall (1944) stated that they may be allied to the pteridosperms, cordaita- leans, or conifers. Occurrence. — Previous records of the oc- currence of these microfossils show them restricted to coal beds of the upper Carbon- dale and lower McLeansboro Groups of Illinois (Schopf, Wilson, and Bentall, 1944) . Present information extends their stratigraphic range down to the Rock Is- land (No. 1) Coal of the Tradewater Group. This genus has not been reported in other coal basins. Parasporites spp. Plate 14, figures 11, 12 Discussion. — Relatively few specimens were found in any one sample and there- fore there is no adequate basis either for referring them to the one described species or for making formal distinction on the specific level. The total size, including bladders, ranges from 257 to 340 /u. In general the specimens found in Trade- water coals seem to have slightly thicker bladder membranes and a more ovoid body outline (pi. 14, fig. 12) than do those illus- trated by Schopf (1938) for Parasporites maccabei. The specimen shown in figure 11 on plate 14 also has a more ovoid body outline and the bladders are disposed lat- erally and distally. The convolute rugose- appearing folds seem to be a result of the bladder membrane folded upon compres- sion rather than the expression of rugosity of the spore body coat. The medial deflec- tion of the suture is commonly obvious, but the third ray is generally not apparent. Wrinkled and poorly preserved specimens of Monoletes, as were noted in three differ- ent coal beds, are superficially similar in appearance and could easily be mistaken for Parasporites. Occurrence. — Parasporites is represented in the Rock Island (No. 1) (maceration 589) , Wiley (maceration 525A-B) , Davis (maceration 518A), DeKoven (maceration 519A) Coals, and an unnamed coal above the DeKoven (maceration 35) , all of the Tradewater Group; in the Colchester (No. 2) (macerations 579B-C, 582), No. 5 (Schopf, 1938; Schopf, Wilson, and Bentall, 1944), Harrisburg (No. 5) (maceration 879), and Herrin (No. 6) (Schopf, 1938; Schopf, Wilson, and Bentall, 1944) Coals of the Carbondale Group; and in the "Di- vide" (maceration 811) , Friendsville (mac- erations 135 and 490D) Coals of the McLeansboro Group. Parasporites is also known from the Danville (No. 7) Coal. The prepollen seems to be most common in an unnamed coal above the DeKoven, Colchester (No. 2), Herrin (No. 6), and the Friendsville Coals, although compared to Monoletes, Parasporites is represented by an insignificant number of prepollen. DESCRIPTIONS OF "SMALL" SPORES Genus Punctatisporites (Ibrahim) Schopf, Wilson, and Bentall, 1944 Punctatisporites obesus (Loose) Potonie and Kremp, 1955 1932 Sporonites obesus Loose, in Potonie, Ibra- him, and Loose, p. 4.51; pi. 19, fig. 49. 1934 Laevigati-sporites obesus Loose, p. 145. 64 ILLINOIS STATE GEOLOGICAL SURVEY 1944 Calamospora (?) obesus (Loose) Schopf, Wil- son, and Bentall, p. 52. 1955 Punctatisporiies obesus (Loose) Potonie and Kremp, p. 43-44; pi. 11, fig. 124. PUNCTAT1SPORITES cf. P. OBESUS Plate 15, figures 1, 2 Description. — Small spores of Punctati- sporites cf. P. obesus are circular to round- ed subtriangular, generally proximo- distally compressed, range from 111 to 151 ix in diameter. Trilete suture is distinct, commonly open; rays extend 26 to 35 [x from proximal pole, equalling in length 35 to 55 percent of the spore radius. Labial development is lacking. Spore coat is 3.8 to 5 [x thick, outer surface smooth, some- times infrapunctate, brown to brownish yellow by transmitted light. Discussion. — The Punctatisporites spores are apparently identical to those originally described by Loose (1932, p. 451) as Sporonites obesus, later described by Po- tonie and Kremp (1955, p. 43-44) as Punc- tatisporites obesus (Loose) . The maximum diameter of the Illinois spores is less than that given by Loose, but somewhat greater than that given by Potonie and Kremp. Ray length on the Illinois spores ranges between one-third of the spore radius (the measurement originally given by Loose) and a little more than one-half of the spore radius (the measurement given by Potonie and Kremp) . Horst (1955) described similar spores from the Namurian A and B and the West- phalian A. These generally are smaller and have a somewhat more variable coat thick- ness and longer rays than those typical of the species. Potonie and Kremp (1955) stated that the spores of Punctatisporites, as they in- terpret the genus, could be allied with the Psilopsida, Filicineae, and Cycadofilici- neae ? . Punctatisporites obesus occurs in the Middle and Upper Westphalian B in the Ruhr Basin (Potonie and Kremp, 1955) . Occurrence. — Spores are common in the Willis Coal (macerations 625A-B) from Gallatin County, and are present in the Tarter Coal (maceration 901) from War- ren County, Illinois. Genus Reticulatisporites (Ibrahim) Schopf, Wilson, and Bentall, 1944 Reticulatisporites irregularis Kosanke, 1950 1950 Reticulatisporites irregularis Kosanke, p. 26; pi. 5, fig. 1. Reticulatisporites cf. R. irregularis Plate 15, figure 3 Discussion. — The spore of Reticulati- sporites cf. R. irregularis is 158 ^ in diame- ter, 32 [X larger than the maximum diameter given by Kosanke, and shows trilete rays, about 20 fx long, in a vaguely denned circu- lar area. The species apparently is re- stricted in occurrence to the "Sub-Babylon" Coal. Occurrence. — This specimen was found in the "Sub-Babylon" Coal (maceration 144), Fulton County, Illinois. Genus Renisporites, n. gen. Type species. — Renisporites confossus (pi. 15, figs. 4, 5), from the Willis and Tarter Coals in Illinois. Symmetry. — Spores of Renisporites are bilateral, monolete. Shape. — Spores originally expanded bean- shaped, oval in plane of longitudinal sym- metry, more or less round in transverse plane. Compression is generally along lon- gitudinal axis, rarely in transverse plane. Size. — Greatest dimension is length, from 126 to 217 ix. Ornamentation. — Spore coat is smooth with scattered puncta or pores completely traversing the spore coat. There are gener- ally two subcircular areas of closely spaced puncta, oriented at the geometrical equator and in the median transverse plane, one on either side of the suture. Haptotypic features. — Suture is straight, monolete, some specimens have low, vague- ly defined, membranous lips, usually longer than half the length of the spore. Well de- fined arcuate thickenings are present, at least at ends of suture and in some speci- GENUS RENISPORITES 65 mens extending completely around and close to the suture. Spore coat. — Coat ranges from 2.5 to 10 ju, in thickness, thickest around ends of su- ture, golden yellow to yellowish brown by transmitted light. Affinity. — Unknown. Discussion. — Spores of this genus are much larger than most of those referred at present to the genus Laevigatosporites (Ibrahim) Schopf, Wilson, and Bentall. Spores of Renisporites have a much thicker spore coat and more clearly defined arcuate ridges. The distinctive ornamentation, dis- crete puncta completely traversing the coat and groups of puncta, is unknown, at pres- ent, on the spores of Laevigatosporites or on any other plant spore. The puncta are superficially similar to those found on the unrelated disseminules of Tasmanites. The spores of Renisporites cannot be considered, on the basis of present informa- tion, as of medullosan affinity because of their generally smaller size, lack of distal grooves, straight rather than medially de- flected suture, and punctate ornamentation. In size they are comparable with, but slightly larger than, the spores of the medullosan Dolerotheca villosa Schopf (1948), but do not possess the distal grooves. Spores of Codonotheca do not pos- sess distal grooves (Schopf, 1948), but do have the typical deflection in the suture. Because of the size of these spores, one would expect only a few to be found in the minus 65-mesh residue upon which small spore studies are based; unless very com- mon, these spores would scarcely be notice- able in the plus 65-mesh residue, especially if the residues are examined dry. Renisporites is apparently represented only in the Willis and Tarter Coals of Illi- nois, but not in all samples of these two coal beds that were examined. The correla- tion of the two coals has been confirmed on the basis of small spores (Kosanke, 1950). Renisporites confossus n. sp. Plate 15, figures 4, 5; text figures 4, 5 Description. — Spores monolete, large for "small" spores, generally compressed par- LENGTH 225/i LENGTH/BREADTH 1.0 1.2 I. 3 I. 4 1.5 Text fig. 4 (above). — Length-breadth measure- ments, groups in 10^ intervals, from 59 spores of Renisporites confossus. Lined area represents holotype. Text fig. 5 (below). — Length-breadth proportions of spores of Renisporites confossus, based on meas- urements given in text figure 4. Lined area rep- resents holotype. allel to the long axis, but rarely folded, probably originally of a somewhat rotund bean-shape. Length ranging from 126 to 66 ILLINOIS STATE GEOLOGICAL SURVEY 217 fx (mean 172.5 ll for 65 specimens); breadth from 113 to 179 yu. (mean 145 ll for 59 specimens) ; length-breadth ratio (text fig. 5) averaging 1.19. Monolete suture dis- tinct, in some specimens open, averaging 57 percent (range 44 to 86 percent) of the spore length, between extremes of 75 ll and 151 fi. Suture terminations usually masked, in proximo-distal compressions (pi. 15, fig. 5a) , by an arcuate thickening of the spore coat. Thickening most conspicuous around the ends of the sutures (pi. 15, fig. 4) , some- times extending as an elongate oval band completely around suture. Lips difficult to distinguish, membranous, up to 3.7 ll in height. Spore coat bearing characteristic and unique type of punctate ornamentation. Discrete puncta or pores, completely trav- ersing spore coat and appearing larger at outer surface of coat, scattered randomly over spore coat (pi. 15, fig. 5a), commonly 10 to 20 ll apart. Generally two fairly well defined subcircular areas of closely spaced punctae, also completely traversing spore coat (pi. 15, fig. 5b) , occurring at the geo- metrical equator on either side of the su- ture, roughly in the median transverse plane (pi. 15, fig. 5a) . Puncta group meas- uring 25 to 40 ll across, sometimes much larger. Spore coat highly translucent, golden yel- low to yellowish brown by transmitted light; coat from 2.5 to 10 ll thick, thickest near terminations of suture (pi. 15, fig. 4) . Holotype. — Maceration 625B-f slide 2, lower part of the Willis Coal, Gallatin County, Illinois (pi. 15, figs. 5a, b) . Discussion. — The histogram presented in text figure 5 characterizes the shape of these spores. The few specimens that possess longitudinal folds are not included. There- fore, the slight skewness — more spores tend- ing beyond the mean towards the elongate rather than isodiametric proportions — can- not be an expression of the tendency to form elongate folds as it is for spores of Monoletes ovatus (Schopf, 1938, fig. 2, p. 44) . In comparison to spores of M. ovatus, these spores tend to be more isodiametric in shape. The actual measurements of length and breadth are shown in text figure 4. Al- though 126 ll is given in the text above as the minimum spore length observed, this is not indicated on the histogram (text fig. 4) because the breadth of this spore is not measurable. The spore coat has a high translucency, somewhat similar to that of the larger spores of Calamospora. It may appear thicker (pi. 15, fig. 5b) in the area of the puncta groups. The puncta and suture do not show as clearly on unstained specimens as on the stained ones (compare figures 4 and 5a on plate 15) . Although the groups of puncta are gen- erally two in number, one on either side of the suture, there is some variation in the number, position, and size of the groups. The holotype (pi. 15, figs. 5a, b) and the spore shown by figure 4 on plate 15 are typi- cal examples. On the latter spore one puncta group is in sharp focus whereas the other, on the opposite side of the spore, is out of focus, just above and to the right in the photograph. A few spores have scattered discrete puncta; one has three groups of puncta; another has two puncta groups covering at least half the spore coat area; the largest spore is completely covered with closely spaced puncta. Worn or poorly preserved spores merely have shredded holes in the coat at the position of the puncta groups. Those specimens that do not have puncta groups appear shallowly infrapunctate. It is possible that this ornamentation is initi- ated on the inner surface of the spore coat. Occurrence. — Renisporites confossus is abundantly represented in the lower part (maceration 625B) , but less abundantly in the upper part (maceration 625A) of the Willis Coal, Gallatin County, and in the Tarter Coal (maceration 901), Warren County, Illinois. A poorly preserved spore, questionably referable to this species, was found in a coal in the Mansfield (?) Forma- tion (maceration 779) in Indiana. OTHER MICROFOSSILS 67 OTHER MICROFOSSILS OF THE PLUS 65-MESH RESIDUES Plant spores are not the only microfossils found in macerated coal residues. Other microfossils, such as fragments of cuticle that may bear the impressions of the orig- inal underlying epidermal cell structure, seed membranes, resin blebs and rodlets, sporangial masses of small spores, or woody fragments, are abundant constituents of some residues. Some papers that are specifically devoted to seed membranes (Arnold, 1948; Schemel, 1950b) have been published in this coun- try. Harris (1956) has recently emphasized the importance of the study of fossil cuticle. Brief mention is given below to some of the various types of plant and animal (?) mi- crofossils that were encountered during this study. Sporangial masses of Densosporites Plate 15, figures 6, 7 Two ovoid sporangial masses, enclosed in a thin membrane, were picked from the maceration residue of the Tarter Coal (maceration 604A) . The more or less com- plete specimen (pi. 15, fig. 6) is about 4200 /a in over-all dimension. The broken specimen, about 2900 ^ in length, was dis- sected and found to contain a mass of spores similar to those of Densosporites lobatus Kosanke. These spores also were seen at the margins of the complete specimen. Somewhat smaller, but empty, sporangial sacs showing cell patterns similar to that illustrated by figure 7 on plate 15 were seen in prepared slides of the shale (maceration 163) above the Pinnick Coal of Indiana. Abundant spores of Densosporites loba- tus were associated with the sacs, but their origin in the sacs is not demonstrable as it is with those from the Tarter Coal. Of course, many sporangial masses of other kinds of small spores, such as Schulzospora in the Mississippian and early Pennsyl- vanian, also were noted, but Densosporites masses are described here because the spores commonly are not found in masses and little was known of their affinity until the recent discovery of this type of spore in the lycopod cone Selaginellites canonbiensis Chaloner (1958a). Seed Membranes Plate 15, figures 8-10; plate 16, figures 1, 2 Seed membranes are present in many coals, but are especially abundant in the coal in the Tar Springs Formation, the "Sub-Babylon" Coal, and in one of the im- pure coals from a sinkhole deposit. Some of the seed membranes from the coal in the Tar Springs Formation are extremely large (pi. 15, fig. 9), and some have well pre- served apical caps (pi. 15, fig. 10) . Large seed membranes also are present in the coal in the Bethel (Moore town) Formation. Although the one shown from the Willis Coal (pi. 16, fig. 1) is well preserved, the folds have obscured details of the apical portion. Membranes like that shown in figure 2 on plate 16 are fairly common in McLeansboro coals. One of the most conspicuous seed mem- branes is illustrated in figure 8 on plate 15. Many of these membranes, very similar to those described as Spermatites reticulatus by Arnold (1948), occur throughout the Pennsylvanian. They were not noted in coals of upper Mississippian age or in those that were studied from the Warrior Basin. In the Caseyville Group they occur in the Wayside (maceration 609) , Battery Rock (macerations 908, 909) , and Reynoldsburg (maceration 618) Coals and in an un- named coal (maceration 798) . In the Tradewater Group they occur in the Baby- lon (maceration 145A-B) , Willis (macera- tion 625A-B) , Pope Creek (maceration 916), Rock Island (No. 1) (macerations 528B, 599B) , New Burnside (maceration 938C) , Murphysboro (?) (maceration 628B) , Bald Hill (maceration 520A) , and Wiley (maceration 525A-B) Coals. In the Carbondale Group they occur in the Colchester (No. 2) (macerations 824, 603C) and Briar Hill (No. 5a) (macera- tion 633A) Coals. In the McLeansboro Group they occur, sometimes commonly, in the Indiana VII (?) (maceration 939A), "West Franklin" (maceration 831A-B), "LaSalle" (maceration 600), Friendsville 68 ILLINOIS STATE GEOLOGICAL SURVEY (macerations 136, 153), "Merom" (macera- tion 146), "Watson" (maceration 148), "Di- vide" (maceration 811), "Woodbury" (maceration 703) , and "Bogota" (macera- tion 133) Coals. Out of twelve instances in which the coal was sampled in two or more portions, these seed membranes are present only, or are more abundant, in the lower samples of ten of the coals. Both resin rodlets and resin blebs are common in some coal beds, generally but not necessarily most abundant in those sam- ples containing abundant Monoletes pre- pollen. Resin blebs may be isodiametric to lenticular, but do not generally show the "stalk" illustrated in figure 3. Resin blebs are easily mistaken for Monoletes prepollen under low power binocular microscope. Miscellaneous Plant Microfossils Plate 16, figures 3-9 At least half of the maceration residue of the Reynoldsburg Coal contains a distinc- tive type of cuticle (pi. 16, fig. 7) . The cuticles are especially reminiscent of the Lepidodendron cuticle illustrated by Bart- lett (1929, especially pis. XIX, XX, XXI) . He describes small cuticular crests, several of which may occur within a single cell out- line as in the case of the areolar dome cells (pi. 16, fig. 7) , and other crests up to thirty times as long as a single cell. Athough most abundant in the Reynoldsburg Coal (maceration 618), this type of cuticle also has been seen in the lowest Caseyville coal in a diamond drill core (maceration 798) , in "Makanda" (maceration 142) , Rock Is- land (No. 1) (maceration 929) , and Col- chester (No. 2) (maceration 603A) Coals. It also occurs in the Pinnick (maceration 150) and Cannelton (maceration 780) Coals in Indiana. The cuticle illustrated in figure 4 on plate 16 shows an arrangement of stoma ta in parallel rows. This arrangement has been noted in cuticles from several samples of Murphysboro Coal. Cuticular fragments such as are illustrated by figures 5 and 6 on plate 16 also occur in Tradewater Coals. The original cells were radially arranged around the circular openings, becoming more regularly six-sided away from the openings. Many macerations contain vascular frag- ments showing various types of structures (pi. 16, figs. 8, 9) . Medullary rays are illus- trated by figure 8 on plate 16. The pit mouths on this fragment are narrow, about 1 0 /a in length, and crossed. Animal (?) Membranes Plate 16, figures 10,11 Membranes that may be animal in origin occur in several coals, such as the coal in the Bethel (Mooretown) Formation, the Tarter, and the lowest Caseyville age coal Text fig. 6. — Macerated coal samples examined for this report came from the counties shaded above. LOCATION OF SAMPLES 69 in a diamond drill core from Wabash County, Illinois. The membranes have nearly circular openings and are orna- mented with closely spaced pits or depres- sions. Small round thickenings are present on the example illustrated from the Tarter Coal (pi. 16, fig. 11). The membranes illustrated in the pres- ent paper are similar to the "Cuticle Type B" of Wilson and Hoffmeister (1956, pi. V, figs. 1,2) in that they have round openings and do not show any cellular structure, but are dissimilar in being thicker and distinct- ly ornamented with tiny depressions. Eisen- ack (1956) and Wills (1959) illustrate sim- ilar membranes or pellicles of, respectively, eurypterids and "scorpions." LOCATION OF SAMPLES Figure 6 indicates the counties in Illinois from which samples of coals and carbona- ceous layers have been collected and mac- erated. Geographic locations are listed by county and maceration number on table 2. Samples from other states, especially from coals of late Mississippian and early Penn- sylvanian age, also were examined. Their geographic locations are given in table 3. In addition, outcrop samples of 15 coals from the Black Creek, Mary Lee, and Pratt Groups from the Warrior Basin, Walker County, Alabama, were examined. Table 2. — Geographic Locations in Illinois Maceration8 Typeb Coalc I vocation Number Quarter Sec. T. R. 561 DD Macoupin Bond County NW NE NE 17 6N 3W 600 579 A-C OU SU "LaSalle" Colchester (Nc Bureau County SE .2) SW NW NW 33 33 16N 16N he he 146 830 OU OU "Merom" Cohn Clark County NW Cumberland County NE SE SW NE 2 21 UN ION 12W 12W 703 OU "Woodbury" SE 32 9N 8E 878 879 880 881 DD DD DD DD Edgar County Grape Creek (No. 6) No. 5 (u) No.S (1) Indiana IV NW NW NW NW NE NE NE NE 1 1 1 1 13N 13N 13N 13N 11W 11W 11W 11W 621D TD DeKoven (?) Edwards County NW NE SE 18 IN 10E 148 OU "Watson" Effingham County SE 1 6N 5E 133 OU "Bogota" Fayette County 25 8N 3E 554D 554E 535 537Q 554F DD DD DD DD DD DeKoven Davis Davis Unnamed coal Stonefort (?, Unnamed coal Stonefort (?) Franklin County SE SE SE just above SE just above SE NE NE NW NW NE NE NE NE SE NE 18 18 16 27 18 5S 5S 6S 6S 5S 2E 2E IE 3E 2E 70 ILLINOIS STATE GEOLOGICAL SURVEY Table 2 — Continued Maceration a Typeb Coalc Location Number Quarter Sec. T. R. Fulton County 603A-C ou Colchester (No. 2) NE NW NE 16 4N 3E 899 ou Colchester (No. 2) W^ NE 16 4N 3E 525A-B ou Wiley NE NW NE 16 4N 3E 527B ou Upper DeLong NE NW SW 19 5N 2E 528A-B ou Rock Island (No. 1) SW SW 23 6N IE 599A-B ou Rock Island (No. 1) SW SW 23 6N IE 602 ou Pope Creek SE SW SE 11 7N IE 604A ou Tarter NW NW SE 19 5N 2E 145A-B ou Babylon NE NE SE 2 5N IE 523A-B ou Babylon NW NE NE 14 7N IE 588 ou Babylon NW NE NE 14 7N IE 144 ou "Sub-Babylon" Gallatin County NE NE SE 2 5N IE 633A-B ou Briar Hill (No. 5a) SE SW SE 17 9S 8E 631 ou Willis (?) South side o f Eagle Valley 625A-B SM Willis Grundy County NW SE 30 10S 9E 580 ST Colchester (No. 2) 12 33N 8E 611 ST Colchester (No. 2) SE SE 9 33N 8E 951 ST Upper coal (Tradewater)1 N^ 11 33N 8E 950A-B ST Lower coal (Tradewater)1 W 11 33N 8E 949 ST Lower coal (Tradewater)1 Hamilton County NV2 11 33N 8E 581 TD No. 2 (?) SW NE SW 19 5S 5E 582 TD No. 2 (?) Hardin County NE NW NE 15 5S 7E 587 MD Battery Rock Henry County 27 US 10E 589 SU Rock Island (No. 1) NE NW SE 3 16N IE 626 SU Rock Island (No. 1) Jackson County NE NE 33 14N IE 549 MD Murphysboro NW NW 36 7S 4W 550 MD Murphysboro NW 30 7S 2W 608 OU Murphysboro SW NE SE 21 7S 3W 799A-C OU Murphysboro 2 7S 3W 800A-C ST? Murphysboro 22 7S 3W 905 MD "Makanda" NE SW SW 28 10S 1W 906 OU "Makanda" NE SW SW 28 10S 1W 907 OU "Makanda" NE SW SW 28 10S 1W 142 OU "Makanda" (Battery Rock?) SE SE 29 10S 1W 143 OU In upper part of Degonia Forma- 13 8S 5W 952 ou tion At top of Palestine Formation2 Jefferson County SE SW 16 8S 5W 811 ou "Divide" Jersey County NW SW SW 7 IS IE 463 ou Summum (No. 4) Johnson County NW SW SE 16 7N 10W 938A-C ST New Burnside SW NE NE 8 us 4E 618 MD Reynoldsburg SW 32 us 4E 609 OU Wayside SE NW NE 4 12S 2E 168 OU In Vienna Formation C sy2 12 13S 4E 687A-B OU In Vienna Formation W3^ SE 12 13S 4E LOCATION OF SAMPLES 71 Table 2. — Continued 567 929 918 917 916 914 908 909 910 629 200 627 936 35 518A-B 628A-B 630 826 825 824 829 828 Maceration8 Typeb Coalc Location Number Quarter Sec. T. R. Johnson County — Continued 765 ou In Vienna Formation cy2 sy2 12 13S 4E 842 ou In Vienna Formation 12 13S 4E 764 ou In Vienna Formation wy2 se 12 13S 4E 758 ou In Vienna Formation wy2 se 12 13S 4E 760 ou In Tar Springs Formation w of c Ey2 sw 10 13S 3E 166 ou In Hardinsburg Formation ("Glen Dean, lower bed") NE NW SE 24 13S 4E 763 ou In Hardinsburg Formation ("Glen Dean, lower bed") Kankakee County NE NW SE 24 13S 4E 203 ou Sinkhole deposit 7 30N 14W 755 ou Sinkhole deposit 7 30N 14W ST OU OU ou ou ou DD DD OU ou MD OU OU OU su ST OU OU OU DD OU OU ou ou ou LaSalle County Colchester (No. 2) NW NE 25 McDonough County Rock Island (No. 1) SW SE SW 23 Mercer County Pope Creek (u) Pope Creek (m) Pope Creek (1) Tarter Perry County Upper part of Menard Formation, 756-758'3 Upper part of Golconda Formation, 1053-1061'3 NE NE NE NE NE NE NE NE SW SW SW SW SW SW NW SW SW NW Pope County Battery Rock (1) NW Battery Rock (u) NW Caseyville SW Battery Rock In Degonia Formation Randolph County Waltersburg Formation4 Rock Island County Rock Island (No. 1) NW Saline County Unnamed coal nine feet above E}4 DeKoven Unnamed coal above DeKoven Davis Murphysboro (?)5 NE Sangamon County Springfield (No. 5) Schuyler County Colchester (No. 2) (u) Colchester (No. 2) (1) Colchester (No. 2) (1) Upper DeLong (?) Middle DeLong (?) SE SE SE SE NW SE NE NE SE SE SE SW SW sy2 NE NE NE NE NE NE 33 33 33 33 31 31 35 6 19 NE 32 SW 20 NW>£ 21 NW 21 NW 27 15 31 31 31 31 31 33N 6N 14N 14N 14N 14N dS 6S us 11s 11s 11s 12s 7S 16N 10S 10S 10s 10s 14N 2N 2N 2N 2N 2N 4E 3W 2W 2W 2W 2W 1W 1W 5E 5E 6E 6E 5E 6W 1W 5E 5E 5E 6E 4W IE IE IE IE IE 72 ILLINOIS STATE GEOLOGICAL SURVEY Table 2. — Concluded Location Maceration* Typeb Coal* Number Quarter Sec. T. R. Wabash County 135 SU? Friendsville 13 IN 13W 153 SU? Friendsville 13 IN 13W 136 OU Friendsville (?) NW 13 IN 14W 490D MD Friendsville NW SW SE 29 2S 13W 583 TD Harrisburg (No. 5) NE SE NW 27 2S 13W 795 DD In Caseyville Group SE NW SE 9 IN 12W 796 DD In Caseyville Group SE NW SE 9 IN 12W 797 DD In Caseyville Group NW/C SW 3 IN 12W 798 DD In Caseyville Group Warren County NW/C SW 3 IN 12W 901 OU Tarter Will County NE 26 9N 1W 455 OU Sinkhole deposit NE NE 22 35N 10E Williamson County 519A-B OU DeKoven NW SW 13 10S 4E 639 OU Unnamed coal just above Stonefort NW SE 25 10S 4E 640 OU Stone fort NW SE 25 10S 4E 520A-B OU Bald Hill NW SE 25 10S 4E 915 OU Murphysboro (?) NW NW 30 9S IE a. not macerated c 1. Doehler (1957) b. DD Diamond drill 2. Rexroad (1957, locality 15) TD Rotary drill 3. Coo per (1942 p. 768) SU Underground mine 4. Reload (195 7, locality 11, samples 3, 4) ST Strip mine 5. Weller, Henbest, an d Dunbar (1942. p. 1« . fig. 2) MD Mi^e dump (1) lower, (m) middle, and (u) upper part of one bed OU Outcrop Table 3. — Geographic Locations in States Other Than ] LLINOIS Macer- Location State and Type Coal County ation number Quartei Sec. T. R. Lawrence 832 OU 834 OU 836 OU Orange 163 OU 150 OU 151 OU Owen 779 OU Perry 780 OU Posey 831 OU 939A DD Washington 468 OU Bell 913 OU Caldwell 206 OU Crittenden 733c SU 810 OU Hardin 943 OU Letcher 911 OU Wise 912 888 OU OU Indiana In Bethel (Mooretown) Formation C E line 11 3N 2W In Bethel (Mooretown) Formation SE 5 3N 2W In Bethel (Mooretown) Formation SE 3 3N 2W Shale above Pinnick SE NW 32 2N 2W Pinnick SW 32 2N 2W French Lick NW 32 2N 2W In Mansfield (?) Formation SW NW 27 12N 4W Cannelton NE 5 7S 2W "West Franklin" (below upper 24 7S 12W bench) VII (?) NW NE SW 12 7S 12W In Bethel (Mooretown) Formation N 1 IN 2E Kentucky In Pennington Shale In Tar Springs Formation Battery Rock In Hardinsburg Formation In Bethel (Mooretown) Formation Coaly streak in upper Stony Gap S ndstone. Streak in upper Stony Gap SS. Virginia Plant bed base (?) of Glen Dean (20 B 70 : Carter grid) (5 G 21 : Carter grid) (C Sy2 5 L 19 : Carter grid) (SW 1 J 18 : Carter grid; (11 P41 : Carter grid) (4 H 83: Carter grid) (4 H 83 : Carter grid) (Big Stone Gap) SPORE DISTRIBUTION 73 SPORE DISTRIBUTION Introduction This discussion of the plus 65-mesh resi- dues of samples from coals and carbona- ceous layers is a supplement to a preceding report on small spores by Kosanke (1950), who studied the small spores from the mi- nus 65-mesh residues. Many of the macer- ated samples were used in both studies. The occurrences of spores noted in the plus 65- mesh residues are given for many of the formations in the Chester Series of the Mis- sissippian System and for many of the coals in the Pennsylvanian System of Illinois. A few Pennsylvanian samples from Indiana and Alabama are included. Those of upper Mississippian age were collected from four states: Illinois, Indiana, Kentucky, and Vir- ginia. In general the samples had been col- lected and macerated long before the im- mediate project was undertaken. This re- port therefore represents a general survey of plus-residue material, with primary em- phasis on "large" spores, or megaspores, al- ready available in the Illinois State Geo- logical Survey collections. The spore distribution chart (text fig. 9) records the presence of 33 designated spe- cies assigned to six genera and the presence of spores of two other genera. Eleven spe- cies and varieties have restricted ranges; others have less restricted but important stratigraphic ranges. Only one species is represented throughout most of the section studied. In order to present a readable distribu- tion chart, when a coal was collected in two or more samples, the assemblages have been reported as a unit for the whole coal. Forms notably restricted to the bottom or top of a bed are discussed in the text. Because the assemblages of various samples of the same coal may differ considerably from place to place, only the assemblage from a coal (maceration number noted on text fig. 9) at one locality is reported. This sample is either one from a locality nearest the type section of the coal (or from the cyclothem in which the type section occurs) or one judged most representative of the whole bed. The assemblages of these sam- ples and of the others studied are discussed in the following pages. Portions of the distribution chart have been abstracted and adjusted to illustrate certain features of spore distribution. Text figure 7 illustrates the contrast between as- semblages of upper Mississippian and im- mediately overlying Pennsylvanian rocks. Text figure 8 represents the stratigraphic distribution of seven genera and that of the spores assigned to the sections of Triletes. These figures are a composite interpreta- tion, in contrast with text figure 9, and are necessarily generalized. Because the samples were not systemat- ically and uniformly taken for the statistical analysis of megaspore content, the terms, "rare" (R), "present" (P), "common" (C), and "abundant" (A) , are subjective and based on the number of specimens ob- served. In general "rare" denotes less than three specimens noted, whereas "abundant" denotes the presence of a hundred or more specimens. When prepared slides only were available for study and the actual relative abundance was unknown, the term "pres- ent" is used unless the maceration records clearly indicate the relative abundance of the various spore types. The occurrences re- ported in text figure 9 have been handled in the same manner; for example, spores of Cystosporites varius are "abundant" in the Rock Island (No. 1) Coal, but "rare" in the DeKoven Coal. Rough percentages of relative abundance of spores of different species are given for some coals in the following discussion. Mississippian System chester series Previous investigations on upper Missis- sippian megaspores in the United States have been limited in extent, primarily be- cause of lack of commercial coals in rocks of this age. Although cyclic sedimenta- tion is evident in the rocks of the Chester Series of the Illinois Basin, formation of coal was limited to a few thin beds and car- bonaceous streaks. Rocks of the Chester Series underlie most of the southern half of Illinois. The 16 alternating limestone-shale 74 ILLINOIS STATE GEOLOGICAL SURVEY ^ fi\&- ^■^m^fj **■ REYNOLDSBURG "MAKANDA" BATTERY ROCK PINNICK UNDO FRENCH LICK (IND.) O Q. UJO E- x KINKAID DEGONIA MENARD WALTERSBURG VIENNA TAR SPRINGS GLEN DEAN HARDINSBURG GOLCONDA CYPRESS Mwmm i ^VWVlVVWWc I'll I I i i "i ■I"* i i i i i i ■ ■ ill. ■■■■ i i i i i i PAINT CREEK YANKEETOWN RENAULT AUX VASES Text fig. 7. — Generalized stratigraphic occurrence of spores of Triletes, Cystosporites, Spencerisporites, Monoletes, and Didymosporites. Coals or formations sampled are indicated by crossed lines (X). Chart illustrates the contrast between the assemblages found in upper Mississippian rocks and those found in the unconformably overlying Pennsylvanian rocks. and sandstone-shale formations average from about 30 to 150 feet thick (Workman, Swann, and Atherton, 1950) . Mississippian coals are rarely more than a few inches thick and less persistent than those known from Pennsylvanian strata (Wanless, 1947) . The 26 samples of thin coals or carbona- ceous layers investigated are from Illinois, Indiana, Kentucky, and Virginia. Those from southern Illinois were collected from Jackson, Johnson, Perry, Pope, and Ran- dolph Counties. Although sample cover- age is by no means satisfactory, it is far more complete than that of previously pub- lished investigations. The samples containing the most abun- dant megaspores are those of the coal in the Bethel (Mooretown) Formation from Ken- tucky and of the coal in the Vienna Forma- tion from Illinois. The assemblages of the samples are here discussed in ascending order of their stratigraphic position. Lower Chester Series No samples were examined from the three lower formations: the Aux Vases Sandstone, Renault Formation, and Yan- keetown Sandstone. The Paint Creek For- mation of the Chester outcrop area is repre- sented, in part, by the Bethel Sandstone in Illinois and by the Bethel (Mooretown) Sandstone in Indiana and Kentucky (Swann and Atherton, 1948) . Five sam- ples of coals within the Bethel (Moore- town) Formation (reported on the distri- bution chart, text fig. 9, as Paint Creek) were examined. The following genera and species have been identified from a 4-inch coal in the Bethel (Mooretown) Formation (macera- tion 943) from Hardin County, Kentucky: SPORE DISTRIBUTION — CHESTER 75 /MISSISSIPPI/ PENNSYLVANIAN (CHESTER / CASEYVILLE / TRADEWATER CARBONDALExMC LEANSBORO SERIES) J GROUP / GROUP / GROUP/ GROUP o '"MS* C) Calamospora cf. C. sinuosa (C,P) T. auritus (C,R) T. globosus var. (C) (C, -) Monoletes (R>R) Cystosporites breretonensis ( -, P) T. superbus (R, - ) One other sample of the Willis (?) Coal (maceration 631) did not contain the great diversity of spore types. T. ramosus is dom- inant; T. mamillarius, T. globosus var. (C), Calamospora cf. C. sinuosa, S. cf. S. radia- tus, and T. triangulatus also are repre- sented. For comparison, the following genera and species were identified from the Tarter Coal (maceration 901), NE14 sec. 26, T. 9 N., R. 1 W., Warren County, Illinois: Triletes brasserti (A) Renisporites confossus n. sp. (A) T. triangulatus (P) Punctatisporites cf. P. obesus (P) Monoletes (P) Calamospora cf. C. laevigata (P) T. ramosus (R) Cystosporites varius (R) Spencerisporites cf. S. radiatus (R) Triletes brasserti is the dominant species, accounting for 90 percent of the mega- spores. T. brasserti also was dominant in the uppermost inch of the Tarter Coal (maceration 604 A) at another locality. Spe- cies from maceration 604 A not represented in maceration 901 are T. auritus, T. ap- pendiculatus?, T. cf. T. eregliensis, and possibly Calamospora cf. C. sinuosa. However, one sample (maceration 914) of the Tarter Coal, 6 inches thick, from Mercer County, has a unique assemblage. Triletes auritus makes up 95 percent of the large spore assemblage; other genera and species represented are T. cf. T. hirsutus, T. horridus, Spencerisporites cf. S. radiatus, Cystosporites, and Monoletes. The assem- blage is unlike those of the other samples of Tarter or Willis Coals, but in the dom- inance of T. auritus and the occurrence of T. cf. T. hirsutus is similar to the assem- blage of the overlying Pope Creek Coal from the same locality. The Willis Coal contains abundant and greatly diverse types of spores. The Tarter Coal, with the exception of the one sample from Mercer County, has a similar but less diversified assemblage, lacking some of the species typical of the Willis Coal, such as Triletes mamillarius and T. globosus var. (C). The two coals are characterized by an abundance of zonate megaspores. Those of T. brasserti even occur in tetrad arrange- ment in both coals. This species also is known from one sample of the Pope Creek Coal. Triangulate spores are abundant as in the Babylon Coal. Kosanke (1950) re- ported Cirratriradites as the subdominant genus of the Willis and Tarter Coals and that it was present in fair abundance in the Babylon Coal. This occurrence of Cirratri- radites parallels the high incidence of tri- angulate megaspores. Both Renisporites confossus and Puncta- tisporites cf. P. obesus appear to be re- stricted to the Willis and Tarter Coals. Tri- letes globosus var. (C) is known only from the two samples of Willis Coal. Spenceri- sporites cf. S. radiatus is present or abun- dant for the first time since its abundant representation in the Reynoldsburg Coal of the Caseyville Group. Monoletes or other evidence of medullosans, such as resin rod- lets, are not common. The assemblages of the Tarter and Willis Coals are among the most distinctive of any of the Pennsylva- nian coals and are readily distinguishable from those of older and younger coals. SPORE DISTRIBUTION— TRADEWATER 85 Pope Creek Coal Kosanke (1950) correlated the Delwood Coal in NWi/4 NW14 sec. 3, T. 11 S., R. 6 E., Pope County, with the Pope Creek Coal (maceration 602) in SE14 SW14 SE14 sec. 11, T. 7 X., R. 1 E., Fulton County. Un- fortunately, the coarse residue of the Del- wood Coal is not now available for exam- ination. The coarse residues studied were from the Pope Creek Coal (5 inches thick) cited above and from the Pope Creek Coal (26 inches thick) from the type locality of the Pope Creek Cyclothem, XE14 NE14 SW14 sec. 33, T. 14 X., R. 2 W., Mercer County, Illinois. The Pope Creek Coal of Mercer County was prepared and studied in three samples: a basal 4-inch block (maceration 916), a middle 12-inch block (maceration 917), and an upper 8-inch block (maceration 918). Because these samples are from an area close to the type locality of the cyclothem, the following list of genera and species iden- tified from them will serve as the standard for the Pope Creek large spore assemblage: Triletes auritus ( -, C,C) Triletes? saturnipunctatus n.sp. (P,-,C) Monoletes (P,R,P) T. cf. T. hirsutus ( -, P,P) Cystosporites varius ( -, -, P) C. verrucosus ( -, -, P) T. triangulatus ( -, P, - ) T. mamillarius ( -, -, R) Both large and small spores are some- what less abundant in the Pope Creek Coal than in the Tarter and Willis Coals. The basal 4 inches of the Pope Creek Coal con- tains a much more varied assemblage than either the middle or upper portions. Tri- letes auritus is dominant; T.f saturnipunc- tatus, T. cf. T. hirsutus, and Monoletes are subdominant. T.f saturnipunctatis appar- ently is restricted to the Pope Creek Coal. The Pope Creek Coal is distinguished from the underlying Tarter Coal (macera- tion 914) at the same locality by the pres- ence of Cystosporites verrucosus, Triletes triangulatus, and T.f saturnipunctatus. It is similar to the older coal in the continued dominance of T. auritus and the common occurrence of spores of T. cf. T. hirsutus. The Pope Creek Coal (maceration 602) from Fulton County, contains a different assemblage. The dominant element in this sample is Triletes augustae; the subdomi- nant elements are T. triangulatus and T. brasserti. In addition Cystosporites gigan- teus, C. varius, and T. mamillarius are rep- resented. This assemblage is similar to that of the underlying Tarter Coal (maceration 604A) in the common occurrence of spores of T. brasserti and T. triangulatus, but dis- similar in the species of auriculate mega- spores. The Pope Creek Coal of Fulton County differs from that of Mercer County in that it contains abundant spores of T. augustae rather than T. auritus, no Mono- letes, Triletes? saturnipunctatus, T. cf T. hirsutus, or C. verrucosus. T. brasserti is not represented in the Mercer County samples. Rock Island (No. 1) Coal The Rock Island (Xo. 1) Coal is an im- portant commercial coal in the Tradewater Group and is known definitely only in western Illinois. It is typically developed in Rock Island and Mercer Counties and is characterized by lenticular occurrence in narrow channel-shaped areas (Cady, 1952) . The large spore content from the coarse residues of six samples from Henry, Rock Island, McDonough, and Fulton Counties is not uniform in character. The following genera and species were identified from a 14-inch coal (maceration 599A-B, — top of bed not represented) , in Fulton County near the type section of the Seville Cvclothem: Cystosporites varius (A,A) Triletes rugosus (-.A) Monoletes (->C) C. breretonensis (->P) T. triangulatus (R.-) T. auritus (*.-) Spencerisporites cf. S. radiatus (R, - ) Calamospora ( -, ? ) Lageniculate megaspores referable to Triletes rugosus appear for the first time in the Pennsylvanian of Illinois. Another sample from the same area (maceration 528A-B) contains the same variety of mega- spores but seems to have a higher propor- 86 ILLINOIS STATE GEOLOGICAL SURVEY tion of Cystosporites breretonensis than C. varius. Monoletes spores and Cystosporites spores with apical tufts are dominant. Kosanke (1950) noted that Lycospora, im- portant in coals above and below the Rock Island (No. 1) Coal, is rare. In contrast, botanically related megaspores of Cysto- sporites and T. rugosus are common in this coal. A 6- to 8-inch coal (maceration 929) from McDonough County differs from the assemblage given above in the dominance of Triletes cf. T. hirsutus and the sub- dominance of T. auritus. Spores of Cysto- sporites varius, T. mamillarius, T. su- perbus, T. triangulatus, T. ramosus, and Calamospora cf. C. laevigata also are pres- ent in this sample. Triletes augustae is dominant in the Rock Island (No. 1) Coal from Pryce mine (maceration 627) , Rock Island County; from Werner mine (maceration 589) , Henry County; and co-dominant with T. ramosus in the sample from Bugos White mine (maceration 626) , Henry County. T. augustae is not known from the other sam- ples of the Rock Island (No. 1) Coal. The only other sample that contained T. ra- mosus is maceration 929 from McDonough County. In the Werner mine sample (maceration 589) one spore of Parasporites was found, representing the first occurrence of that genus in the Pennsylvanian of Illinois. None of these northern Illinois samples contains the smooth lageniculate spores found in the Fulton County samples; spores of Cystosporites and Monoletes range from rare to present. The lack of Lycospora (Kosanke, 1950) in the Rock Island (No. 1) Coal from Henry and Rock Island Counties parallels the lack of lageniculate spores and the lack or extreme rarity of Cystosporites spores. The assemblages from the Rock Island (No. 1) Coal of northern Illinois compare relatively closely with that found in the coal at New Burnside (maceration 938) from Johnson County in southern Illinois. Murphysboro Coal The Murphysboro Coal in southern Illi- nois is another commercially important coal in the Tradewater Group (Cady, 1952) . The coal ranges from 1 to 7y2 feet thick and tends to split into two benches toward the margins of the Murphysboro area to the east and north (Cady, 1952) . Its maximum thickness occurs only in Jack- son County. Its exact equivalent outside of Jackson and Williamson Counties is un- known. The following genera and species have been identified from a sample (maceration 550) from the mine dump of the aban- doned Brinker mine near Oraville, Jackson County: Triletes triangulatus (A) T. rugosus (C) Cystosporites varius (P) C. breretonensis (P) C. giganteus (P) T. auritus (P) Monoletes (R) The uppermost 12 inches (maceration 608) of the Murphysboro Coal from south of Sato only rarely contains spores of Cysto- sporites varius and Triletes triangulatus. Spores of T. augustae are common and a few specimens of Monoletes are present in maceration 549 from an abandoned slope mine south of Ava. Two samples of Murphysboro Coal (macerations 799 and 800) were given only a cursory examina- tion; T. triangulatus and auriculate mega- spores were present. A coal (maceration 915) occurring under the sandstone in the spillway of Crab Orchard Lake dam, NW14 NW14 sec. 30, T. 9 S., R. 1 E., Williamson County, has a spore content generally similar to that of the Murphysboro Coal. In this coal Triletes rugosus and Monoletes are co-dominant; Cystosporites giganteus and T. mamillarius are represented by only a few spores. The assemblage differs from that of the Murphysboro in its lack of T. triangulatus and tufted Cystosporites spores. A coal (maceration 628A-B) below the Curlew Limestone (Weller, Henbest, and Dunbar, 1942, p. 15, fig. 2), NE14 SE14 NW1/4 sec. 27, T. 10 S., R. 6 E., Saline SPORE DISTRIBUTION — TRADEWATER 87 County, contains spores of the following genera and species: Triletes auritus (A,A) Monoletes (C,C) T. rugosus ( -, A) Cystosporites giganteus ( -, P) C. sp. (R, - ) T. triangulatus ( -, R) T. mamillarius ( -, R) This coal differs from that of the Murphys- boro in the dominance of T. auritus rather than T. triangulatus and in the absence of tufted spores of Cystosporites. Cady (1952) suggested that a coal, 4 to 5 feet thick, lying below the Curlew Sand- stone near New Burnside, Johnson County, may be the equivalent of the Murphysboro Coal. A sample (maceration 938A-C) from a coal 43 inches thick in a strip mine in that area contains spores of the following genera and species: Monoletes (A,P,P) Triletes augustae ( -, C,A) T. triangulatus (R.P.P) Cystosporites varius ( -, R,A) T. ramosus (C, -, - ) T. auritus (R,R, - ) C. breretonensis ( -, -, P) C. giganteus (R, -, - ) T. rugosus ( -, R, - ) In the presence of Triletes augustae and T. ramosus and the rarity of T. rugosus, the assemblage resembles those of the Rock Island (No. 1) Coal from northern Illi- nois. In the same respect maceration 938A- C differs from most of those from the Mur- physboro Coal, except for one or two in which T. augustae is represented. This New Burnside sample is the only one in south- ern Illinois with spores of T. ramosus at this general horizon. Bald Hill Coal The Bald Hill Coal may be as much as 28 inches thick but it is not considered as important economically as the Rock Island (No. 1) , Murphysboro, or some of the over- lying coals of the Tradewater Group. It has been suggested, Kosanke (1950) noted, that it is equivalent to the Upper DeLong Coal of western Illinois. The following genera and species were identified from the Bald Hill Coal (macer- ation 520A-B) near its type locality, NW14 SE14 sec. 25, T. 10 S., R. 4 E., Williamson County: Triletes auritus (C, - ) Cystosporites varius (C, - ) C. breretonensis (P, - ) T. rugosus (P, - ) Monoletes (P, - ) Calamospora cf. C. laevigata (R, - ) This assemblage differs from those of the Murphysboro Coal mainly in the lack of Triletes triangulatus, and it differs from the coal bed below the Curlew Limestone (maceration 628A-B) in that tufted Cysto- sporites spores are present. One sample of the lower bench of the Upper DeLong Coal (maceration 527B) from Fulton County was barren of megaspores. One sample of Middle DeLong Coal (?) (maceration 828) from Schuyler County, contained only a few spores of T. triangulatus and Monoletes. A sample of Upper DeLong (?) Coal (maceration 829) from the same lo- cality contained the same spores as the Middle DeLong (?) and a few spores of Cystosporites breretonensis. Stonefort Coal The Stonefort Coal lies above the Bald Hill Coal and below the Stonefort Lime- stone. The coarse residue of this coal (mac- eration 640) near the type Stonefort Cyclo- them, Williamson County, yielded only a few spores of Monoletes and Triletes tri- angulatus. An unnamed coal (maceration 639) , just above the Stonefort Coal, near the same locality, yielded only a few spores of Cystosporites giganteus, T. auritus, T. tri- angulatus, and more abundant spores of Monoletes. The residue of this coal con- sisted almost entirely of cuticle. One sample of a 12-inch coal (macera- tion 554F) , questionably the unnamed coal just above the Stonefort Coal, Franklin County, contained a few spores of Triletes auritus and Cystosporites breretonensis. Another sample of an 11 -inch coal (macer- ation 537Q) , also questionably the un- named coal just above the Stonefort Coal, contained only cuticle and spores of C. breretonensis. Davis and Wiley Coals The Davis Coal, generally of minable thickness in southeastern Williamson and 88 ILLINOIS STATE GEOLOGICAL SURVEY southern Saline Counties, southeastern Illinois, lies above the Stonefort Limestone and from 15 to 40 feet below the DeKoven Coal. This coal has been correlated with the thin but persistent Wiley Coal of west- ern Illinois (Wanless, 1939; Kosanke, 1950; Wanless, 1955) . The Wiley Coal lies above the Seahorne Limestone and below the Greenbush Coal. The following genera and species were identified from the Davis Coal (maceration 518A-B), Saline County: Triletes triangulatus (A, - ) T. rugosus (P,R) Monoletes (P,R) Cystosporites giganteus (?, - ) Parasporites (R, - ) Spencerisporites cf. S. gracilis ( -, R) Two other samples from Franklin Coun- ty, possibly of the Davis Coal, also were examined; one (maceration 535) contained no identifiable spores, and the other (mac- eration 554E) contained only a few frag- ments of cuticle, resin rodlets, and spores of Monoletes. The Wiley Coal (maceration 525A-B) , 1 1 inches thick, Fulton County, has an as- semblage remarkably similar, with respect to the variety and relative abundance of spores, to that of the Davis Coal. However, in the Wiley Coal the spores are generally more abundant and, in addition, spores of Triletes mamillarius are common and T. aaritus and Cystosporites varius are pres- ent. The two coals seem to be character- ized by the joint, but rare, occurrence of spores of Parasporites and Spencerisporites cf. S. gracilis. DeKoven Coal The DeKoven Coal, 30 to 36 inches thick in Saline and Williamson Counties, over- lies the Davis Coal and is the highest named coal in the Tradewater Group of southeastern Illinois. In places it has been cut into or entirely cut out by the Palzo Sandstone, the basal unit of the Carbon- dale Group. The Greenbush Coal of west- ern Illinois has been correlated with the DeKoven Coal by Wanless (1939), a cor- relation corroborated by studies of small spores (Kosanke, 1950) . Wanless (1955) stated that the Greenbush Coal of western Illinois is generally absent or represented by only a thin film of carbonaceous material. The following genera and species were identified from the DeKoven Coal (macer- ation 519A-B), Williamson County: Triletes triangulatus (C,P) Monoletes (?,?) Spencerisporites cf. S. gracilis (P,C) Parasporites (R>R) Cystosporites giganteus ( -, R) C. varius ( -, R) The DeKoven Coal generally is distin- guishable from the underlying Davis Coal by the lack of Triletes rugosus. T. triangu- latus and Monoletes seem to be dominant elements in both coals. A sample of the DeKoven (?) Coal (mac- eration 554D) from a Franklin County core yielded only rare spores of Monoletes, Cala- rnospora, and Triletes rugosus. The latter species is unknown from the DeKoven Coal (maceration 519A-B) from Williamson County. A coal was found about 9 feet above the DeKoven Coal, Ei/2 NE14 NE14 sec. 20, T. 10 S., R. 5 E., Saline County. Two hundred feet to the west the coal was absent. The following genera and species have been identified from this unnamed coal (mac- eration 936) : Triletes rugosus (P) T. auritus (P) Monoletes (?) Cystosporites varius (R) T. ramosus ? (R) T. triangulatus, Parasporites, and Spenceri- sporites cf. S. gracilis, found in the under- lying DeKoven Coal, are not represented. T. rugosus and T. auritus are not known from the DeKoven Coal. A sample of an unnamed coal 12 inches thick (maceration 35) occurring above the DeKoven Coal in the NW14 sec. 21, T. 10 S., R. 5 E., Saline County, Illinois, contains an assemblage similar to that of the De- Koven Coal (with one exception) in re- spect to kinds of spores and to relative abundance of the different types. In gen- eral, large spores seem to be more abundant in this unnamed coal, which, in contrast to the DeKoven Coal, contains some spores of Triletes mamillarius, Calamospora cf. C. laevigata, and one questionably referred to SPORE DISTRIBUTION — CARBONDALE 89 T. rugosus, but no spores of Spencerispo- rites cf. 5. gracilis, which are fairly common in the DeKoven Coal. A pre-No. 2 coal (maceration 62 ID) , penetrated by a rotary drill in Edwards County, has a large spore assemblage much more similar to that of maceration 936 than to that of the DeKoven Coal. This coal does not contain any zonate spores, but contains the others listed for the unnamed coal (maceration 936) 9 feet above the De- Koven Coal. In addition a few spores of Trilctes mamillarius, Cystosporites gigan- teus, and possibly one of T. augustae are present. Miscellaneous Coals Two of the lower coals from the Illinois Clay Products pit near Goose Lake, Grundy County, were examined. The Colchester (No. 2) Coal mined in this area lies above these coals outside the vicinity of the pit. The lower of the two coals may be as much as 6y4 inches thick and is persistent but somewhat irregular in thickness, thin- ning to 1 1/9 inches within the area of the pit (Doehler, 1957) . The following genera and species were identified from this coal at its maximum thickness (maceration 950A-B) : Monoletes (A»p) Triletcs superbus (P»P) Cystosporites varius ( -, R) T. mamillarius ( -, R) T. appendiculatus ? ( -, R) T. ramosus ( -, R) The other sample (maceration 949) of this coal contains only one spore of Spenceri- sporites, unidentifiable as to species. Tri- letcs appendiculatus? is known from only one other sample, the Tarter Coal (macera- tion 604A) . T. superbus is known from the "Sub-Babylon" (maceration 144) , Willis (maceration 625A) , and Rock Island (No. 1) (maceration 929) Coals. The upper of the two coals, about 3i/2 inches thick, is not persistent. Maceration 951 contained only abundant spores of Monoletes. Summary The lower coals of the Tradewater Group, especially the Tarter and Willis Coals, are characterized by a wide variety of megaspores and a maximum develop- ment of some of the zonate spores, such as those of Triletcs brasserti. In addition Renisporites and Punctatisporites cf. P. obesus seem to be restricted to these coals. With the exception of one sample of the Tarter Coal (maceration 914) , the coals of the Tradewater Group lack spinose lageniculate spores that are so common in the coals of the Caseyville Group. How- ever, the smooth, lageniculate megaspores are prominent in the Rock Island (No. 1) , Murphysboro, and younger coals of the Tradewater Group. Parasporites and Spen- cerisporites cf. S. gracilis, although never abundantly represented, are conspicuous in several of the upper coal beds of the Trade- water Group. Triletes glabratus, repre- sented in the "Makanda" Coals of the Caseyville Group and generally conspicu- ous in the coals of the Carbondale Group, has not been recognized in Tradewater Coals. CARBONDALE GROUP The Carbondale Group, next higher stratigraphic division of the Pennsylvanian in Illinois, extends from the base of the Palzo Sandstone in southern Illinois and from the base of the Isabel Sandstone in western Illinois to the base of the Anvil Rock Sandstone. The group, up to 400 feet thick (Cady, 1952) , contains more promi- nent marine limestone than does the Trade- water Group and exhibits a more regular cyclic alternation of beds. Some of the coals are extensive; Colchester (No. 2) , No. 5, and Herrin (No. 6) Coals are the commer- cially important coals of Illinois. The Summum (No. 4) Coal is less extensive and the Briar Hill (No. 5a) Coal is re- stricted essentially to southeastern Illinois (Kosanke, 1950) . The Carbondale Group is considered generally equivalent to the middle third of the Desmoinesian Series of the Mid- continent region, to the middle portion of the Allegheny Series of the Appalachian re- gion (Wanless, 1955) , and to the West- phalian D, at least in part, of Europe (Kremp, 1955) . At least the upper part of the group contains the flora of zone 7 (Zone 90 ILLINOIS STATE GEOLOGICAL SURVEY of Neuropteris flexuosa) of Read (1947) . Bhardwaj (1957) considers the lower part of the Illinois Carbondale Group as the transition zone and Briar Hill (No. 5a) and Herrin (No. 6) Coal as roughly equivalent to seam 1 (Stolberg) of the Saar and to the Velener Schicten (Lower West- phalian D) of the Ruhr. Discussion of the large spore occurrences is based on a study of 24 samples from eleven Illinois counties. J. M. Schopf's ex- tensive report on the megaspores from Her- rin (No. 6) Coal is discussed below and incorporated into the spore distribution chart (text fig. 9) . Primary emphasis has been placed on the coals of the Caseyville and Tradewater Groups so that discussion of those coals in the Carbondale and McLeansboro Groups is held to a minimum. Colchester (No. 2) Coal Wanless (1955) stated that the Colches- ter (No. 2) Coal is the most extensive Pennsylvanian coal in the United States. Unlike most other coals in Illinois, it has its maximum development in the northern part of the basin. The small spore content of the Colches- ter (No. 2) Coal in northern, western, and southern Illinois is uniform; the floral ele- ments of the thinner coal in southern Illi- nois are in approximately the same relative abundance as in the thicker Colchester (No. 2) Coal from western and northern Illinois (Kosanke, 1950) . Samples of Col- chester (No. 2) Coal (and probable No. 2 Coal) from nine localities were examined for large spore content. The variation in megaspore content between these coals is marked. The following genera and species were identified from the Colchester (No. 2) Coal (macerations 824, 825, and 826), more than 30 inches thick, outcropping in Mill Creek, Schuyler County: Cystosporites giganteus (C, A, C) Monoletes (P, C. C) C. varius (P, C, P) C. breretonensis (P, C, P) Triletes rugosus (C, -, A) C. verrucosus (C, R, P) T auritus (A, -, ■) T triangularis (P, -, -) Calamospora cf. C. laevigata (P, -, - ) The sample from the bottom portion of the bed is dominated by spores of Triletes mgosus, accounting for about 50 percent of the assemblage. Cystosporites spores clearly dominate in the middle sample of the bed. T. auritus is dominant in and re- stricted to the upper 2 feet of the coal. T. triangulatus and Calamospora cf. C. laevi- gata also appear to be restricted to the upper portion of the bed. The high inci- dence of spores of T. rugosus and Cysto- sporites parallels the reported dominance (Kosanke, 1950) of the botanically related small spores of Lycospora. Another outcrop sample of the Colches- ter (No. 2) Coal 19 inches thick (macera- tion 603 A-C) , from Fulton County, con- tains all the genera and species of macera- tions 824, 825, and 826, except Cystosporites verrucosus. Triletes mamillarius is repre- sented by rare spores in the bottom 4 inches of the bed. In addition to a different megaspore distribution throughout the bed, Cystosporites seems to be less well represented. Another sample of the Colchester (No. 2) Coal (maceration 899) from Fulton County only contains abundant spores of Monoletes and rare spores of Triletes triangulatus. Four samples of Colchester (No. 2) Coal from northern Illinois were examined. One (maceration 579A-C) from the Spring Val- ley No. 3 mine, Bureau County, had repre- sentatives of the genera and species given for macerations 824, 825, and 826 above, except Cystosporites verrucosus and Tri- letes auritus. In addition, Parasporit'js is known from the lower two-thirds of the bed; however, as in macerations 824, 825, and 826, Cystosporites and Monoletes are dominant. Two samples from Grundy County ex- hibit extreme variations in large spore con- tent. One (maceration 611) contains spores of Triletes rugosus, Monoletes, Calamo- spora cf. C. laevigata, T. triangulatus, and Cystosporites breretonensis. T. rugosus is dominant; Monoletes is subdominant. The other sample from Grundy County (macer- ation 580) contains fairly abundant spores of Cystosporites. Monoletes is rare, in SPORE DISTRIIH'TION — CARBONDALE 91 marked contrast to the other samples of Colchester (No. 2) Coal. None of the spe- cies of Triletes in macerations 824-826 nor Calamospora is represented. In contrast to all other samples of the Colchester (No. 2) Coal, T. augustac and Spencerisporites cf. S. gracilis are found in maceration 580. The fourth sample of this coal (macera- tion 567) , from LaSalle County, contains no mega spores. Two samples, questionably of the Col- chester (No. 2) Coal, from rotary drill samples, Hamilton County, were examined. One (maceration 581), probably is a coal of Tradewater age, in that Triletes ramosus with adhering spores of Densosporites was identified. The other (maceration 582) contains some of the more common spores found in the Colchester (No. 2) Coal. All of the genera and species represented in the Colchester (No. 2) Coal occur in some of the underlying coals of the Trade- water Group. Although the assemblages from different localities vary considerably, they appear to differ from those of the upper part of the Tradewater Group by 1) a lower incidence of Parasporites and Spencerisporites, 2) greater relative abun- dance of Cystosporites, and 3) fewer spores of Triletes triangulatus. All the samples are distinguishable from the Summum (No. 4) Coal and the overlying coals of the Carbondale Group by the greater rela- tive abundance of Cystosporites and the ab- sence of T. glabratns (text fig. 9) . C. verru- cosus is represented in the Indiana Coal IV but is not known to occur in any younger coal. Indiana Coal IV The Indiana Coal IV is geographically restricted to an area centering in Greene County, Indiana (Wanless, 1955) . It is known to extend into parts of Edgar, Clark, Crawford, and Lawrence Counties of Illi- nois. This coal occurs between the Col- chester (No. 2) and the Summum (No. 4) Coals of Illinois. The Indiana Coal IV is split in a dia- mond drill core from Edgar County, Illi- nois. The thinner (8-inch) lower coal of the split (maceration 881) is dominated by spores of Triletes rugosus (80 percent) . Monoletes, Cystosporites varius, C. gigan- teus, and C. verrucosus also were well rep- resented. The assemblage from this coal is similar in content to that of several sam pies of the Colchester (No. 2) and in the relative abundance of Cystosporites, T. ru- gosus, and Monoletes. In this core the In- diana Coal IV is distinct from the overly- ing No. 5 and Grape Creek (No. 6) Coals, which contain numerous spores of T. glab- ratns but lack those of Cystosporites. Summum (No. 4) Coal Summum (No. 4) Coal is extensive in southern Illinois, although commonly only a few inches thick. Its equivalent, Indiana IVa, locally attains a thickness of from 1 to 2 feet in Indiana. This coal, like the Rock Island (No. 1) Coal in western Illinois (Cady, 1952), is lenticular. The following genera and species were identified from one sample of the Summum (No. 4) Coal (maceration 463) , Jersey County: Triletes triangulatus (A) T. glabratns (C) T. augustae (C) T. mamillarius (P) Calamospora cf. C. laevigata fp) Monoletes (R) This assemblage is distinct from those of most samples of the Colchester (No. 2) , No. 5, Briar Hill (No. 5a) , and Herrin (No. 6) Coals, in its lack of Cystosporites, Triletes rugosus, and the relative rarity of Monoletes. T. glabratns is abundant for the first time in the Pennsylvanian of Illi- nois. The only previous occurrence was the few spores found in the "Makanda" Coals of the Caseyville Group. Although Lyco- spora is dominant among the small spores (Kosanke, 1950) , none of the megaspores known to be botanically related to Lyco- spora are present in this sample of the Summum (No. 4) Coal. No. 5 Coals The No. 5 Coal of Illinois, called Har- risburg (No. 5) in southern Illinois and Springfield (No. 5) in central, western, and northern Illinois, is second to Herrin (No. 6) Coal in commercial importance in Illinois. 92 ILLINOIS STATE GEOLOGICAL SURVEY The following genera and species were identified from the Springfield (No. 5) Coal (maceration 630) , Sangamon County: Monoletes (A) Triletes glabratus (P) T. triangulatus (P) Cystosporites varius (P) T. auritus (R) T. rugosus (R) T. mamillarius (R) Spencerisporites cf. S. gracilis (R) Calamospora cf. C. laevigata (R) This sample and another (maceration 583) from Wabash County differ from the Summum (No. 4) Coal in that T. rugosus and Cystosporites are present. Three sam- ples of the No. 5 Coal contained fairly abundant spores of T. glabratus. This spe- cies is also noted in two other samples of the No. 5 Coal (macerations 422C and 569D, not listed in table 2) . A diamond drill core sample of No. 5 Coal (macerations 880 and 879) from Ed- gar County did not contain any spores of Cystosporites or Triletes rugosus and was similar to the sample of Summum (No. 4) Coal in this respect. It did, however, con- tain fairly abundant spores of T. glabratus and representatives of both Spencerisporites and Parasporites. Briar Hill (No. 5a) Coal Briar Hill (No. 5a) Coal is generally re- stricted to the southeastern part of the Illi- nois Basin and is rarely mined. The following genera and species were identified from the Briar Hill (No. 5a) Coal (maceration 633A-B) from the gen- eral area of its type section in Gallatin County, where it is 2 feet thick. Monoletes (A, A) Triletes rugosus (A, C) Cystosporites giganteus (A, - ) C. varius (A, - ) T. triangulatus (P, P) Calamospora cf. C. laevigata (C, - ) Spencerisporites cf. C. gracilis (P, - ) Cystosporites breretonensis ( -, R) T. glabratus ( -, R) This assemblage differs from those of the No. 5 Coal in the rarity of spores of Triletes glabratus, and in the more abun- dant occurrence of spores of T. rugosus and Cystosporites. Only Calamospora and T. rugosus have been identified from one other sample of Briar Hill (No. 5a) Coal (macer- ation 507 A-B, not listed in table 2) . Herrin (No. 6) Coal The Herrin (No. 6) Coal is the princi- pal commercial coal of Illinois. It may at- tain a maximum thickness of 14 feet or more. The extensive study by Schopf (1938) of the megaspores of this coal is well known. His results have been incor- porated into the distribution chart (text fig. 9) . The dominant elements appear to be Triletes glabratus, T. rugosus, Mono- letes, T. triangulatus, T. mamillarius, and Cystosporites. A sample (maceration 878) of Grape Creek (No. 6) Coal from Edgar County contained very abundant spores of Triletes glabratus, but none of Cystosporites. Apparently Spencerisporites, found in two samples of the No. 5 Coal and in one of the Briar Hill (No. 5a) and one of the Colchester (No. 2) Coals, is not represented in the Herrin (No. 6) Coal. The larger spores of Calamospora, noted in several samples of the No. 2 Coal, the Summum (No. 4) Coal, and in one sample of both the No. 5 and No. 5a Coals, also are miss- ing. Parasporites is common for the first time since its occurrence in an unnamed coal above the DeKoven Coal of the Tradewater Group, although scattered occurrences are noted in the No. 2 and No. 5 Coals. Summary The coals of the Carbondale Group, above the Colchester (No. 2) Coal and the Indiana Coal IV, are distinguished from older coals by a fairly abundant occurrence of both the spinose and smooth aphanozo- nate megaspores. Spores of Triletes gla- bratus first occur in "Makanda" Coals of the Caseyville Group, are absent from coals of the Tradewater Group and from Col- chester (No. 2) Coal and Indiana Coal IV, but reoccur, at many places in great abun- dance, in the younger coals of the Carbon- dale Group. Spores typical of T. auritus are not as common in the Carbondale coals as they are in some of the Tradewater coals. Spores of the section Zonales of Triletes apparently are not represented in the Car- bondale and younger coals. SPORE DISTIMU'TION — McLEANSBORO 93 M(. I.EANSBORO GROUP The McLeansboro Group is the upper- most group of the Pennsylvanian in Illi- nois. The base of the group is defined as the base of the Anvil Rock Sandstone. The group is more than 1200 feet thick and is composed predominantly of shales, silt- stones, and sandstones, with numerous ma- rine limestones and thin lenticular coals. Cady (1952) noted the presence of from 22 to 27 coals or coal horizons within the group. Of these, the Jamestown, Danville (No. 7) , Friendsville, and Trowbridge Coals are of economic importance. The group is considered to correspond to the upper third of the Desmoinesian Series, the Missourian Series, and possibly to part of the Virgilian Series, all of the Midconti- nent region; to the upper Allegheny and Conemaugh Series of the Appalachian Basin (Wanless, 1 955) ; and possibly to part of the Westphalian D and Lower Stephan- ian of Europe (Kremp, 1955) . Kosanke (1950) noted a major change in the flora shortly after the beginning of Mc- Leansboro deposition but prior to the depo- sition of the Trivoli (No. 8) Coal. No species of Lycospora is known from the Trivoli (No. 8) Coal nor from overlying coals. The change essentially conforms to the Desmoinesian-Missourian boundary of the M idcontinent region and agrees with a major faunal change discussed by Dunbar and Henbest (1942) . Only 14 samples of McLeansboro coals or coaly streaks, principally from six coun- ties in south-central Illinois, have been ex- amined. Most of the samples are from units overlying the Trivoli (No. 8) Coal, or in other words, occurring above the major floral change discussed by Kosanke (1950) . The sequence in which the units are listed on the distribution chart (text fig. 9) should be regarded as tentative because many stratigraphic problems in the Mc- Leansboro Group have not yet been re- solved. Each of the assemblages given on the dis- tribution chart represents a single sample from each unit given; therefore, discussion of these assemblages is unnecessary. In ad- dition to the strata shown on the distribu- tion chart, a few slides from three other units were examined. Parasporitcs, Mono- letes, Triletes triangulatus, and T. glabra- tus are known from the Danville (No. 7) Coal. T. glabratus, Monoletes, and auricu- late spores are known from the Macoupin Coal. Monoletes and auriculate spores also are known from the Flannigan Coal. Be- cause the total assemblages from these coals were not examined, they have not been given on the distribution chart. In contrast to the occurrence of Triletes mamillarius in some of the coals of the Carbondale Group, the species is not repre- sented in the McLeansboro Group. Neither T. riigosus, except for one questionable specimen, nor Cystosporites is known from the Trivoli (No. 8) or younger coals. This parallels the absence of the small spores of Lycospora. However, lageniculate-type spores, T. lev is, are very common in upper McLeansboro coals. In general, the upper McLeansboro coals — Trivoli (No. 8) and those above — seem to be characterized by the presence of common cuticles, seed membranes, the rather small large spores of Parasporites, Monoletes, Spencerisporites, and Calamo- spora; megaspores of Triletes glabratus and T. levis and of the auriculate type; and by rather rare occurrences of the triangulate megaspores. Discussion upper mississippian Published studies concerning plant mega- spores of Mississippian age from localities in North America are few (Chaloner, 1954b, three samples at three localities; Schemel, 1950a, one sample) . Even the small spore studies have been neglected, mainly for economic reasons, although not to as great an extent since oil companies have increased their interest in this phase of paleobotany (for example, Hoffmeister, Staplin, and Malloy, 1955). More pub- lished studies, at least in part dealing with some of the older coals, are available from Europe (Dijkstra, 1952b; Nowak and Zerndt, 1936; Zerndt, 1934, 1937a; Horst, 1955; Potonie and Kremp, 1955, 1956) be- 94 ILLINOIS STATE GEOLOGICAL SURVEY cause many of their older coals are of com- mercial importance. Schemel (1950a) reported the occurrence of spores of Triletes agninus (Zerndt) , Schopf, Wilson, and Bentall and a single specimen referred to T. radiatus Zerndt (T. radiosus Schopf, Wilson, and Bentall) from a coal of Chester or Springer age in Utah. Zerndt (1937a) originally described spores of these species and of T. splendidus (Zerndt) Schopf, Wilson, and Bentall from the Dinantian and Namurian A of the Up- per Silesian Coal Basin of Poland. All three species have about the same strati- graphic range in this basin. Although a few spores of T. splendidus were found in the uppermost Chester sample examined, nei- ther of the two species reported by Schemel (1950a) was represented. Chaloner (1954b) described megaspores of probable Osage or Kinderhook age and some from the Beaver Bend Limestone in the lower part of the Chester Series in Indi- ana. Spores reported from the Beaver Bend Limestone are those of Triletes subpilosus forma major, T. indianensis, T. echinoides, T. paleocristatus (Chaloner, 1956b) , and Cystosporites giganteus. All except the latter two species of Triletes were repre- sented in the coal in the Bethel (Moore- town) Formation of Kentucky, and T. ech- inoides was noted, as occurring sporadi- cally, higher in the section. No specimens of T. paleocristatus were seen during this investigation. Only spores of T. indianen- sis seem to be restricted to the lower part of the Chester; Didymosporites is appar- ently abundantly represented only in the lower part of the Chester; spores of both T. subpilosus forma major and C. giganteus occur, at some places abundantly, through- out the Chester, the latter species alone ex- tending up into Pennsylvanian rocks. Spores other than those described by Chal- oner also were found; several of them, or of closely related forms, occur in the lower- most Pennsylvanian coals of Illinois. Chaloner's interpretation of a lepido- dendrid-lepidocarp flora, based on mega- spores, is still applicable to the Chester as a whole. From what is known of cone studies, Chaloner's interpretation implies a great abundance of the small spores of Lycospora in the Chester Series and this is borne out by the study of Hoffmeister, Staplin, and Malloy (1955) on the Hardinsburg Forma- tion. PENNSYLVANIAN The spores reported by Arnold (1950) from the Michigan Basin, with the excep- tion of Triletes rugosus, compare favorably with those found in coals from the Makan- da Sandstone of the Caseyville Group up to and in Pope Creek Coal of the Tradewater Group in Illinois. The species from Ar- nold's localities 9 and 11 may occur in Illi- nois Caseyville coals; most, except T. rugo- sus and possibly T. ramosus, from his lo- calities 1, 8, and 10, also are known from the "Makanda" Coals of Illinois. T. bras- serti, from Arnold's localities 4 and 6, is known in Illinois only from the Tarter, Willis, and Pope Creek Coals of the Trade- water Group. In general terms, therefore, the spores described from the Michigan Basin by Arnold (1950) are similar to those commonly found in coals of the upper part of the Caseyville Group and the lower part of the Tradewater Group. Bailey (1936) , in a description of micro- fossils from the shales of the Cherokee For- mation and lower part of the Henrietta Formation of central Missouri, illustrated and discussed a few megaspores. His illus- trations imply that he found spores of Tri- letes auritus and T. mamillarius in a sink- hole or channel-fill deposit at the base of the Pennsylvanian section, spores of T. augustae from the Bevier (?) Coal, Cysto- sporites? and weakly to strongly apiculate aphanozonate megaspores from the Tebo Coal. Abortive and small, apiculate aphan- ozonate megaspores are illustrated from the Mulky Coal. In general, the stratigraphic occurrences of the spores that Bailey illus- trated are concordant with the occurrence of similar spores in the coals of the Illinois Basin. A discussion of Schopf 's (1936a, 1936b, 1938) extensive studies on the megaspores of the Herrin (No. 6) Coal of Illinois has been included in previous discussion of that coal. The assemblage of that coal is SPORE DISTRIBUTION — McLEANSHORO 95 more or less typical of those assemblages in the upper coals of the Carbondale Group but differs in some respects and may prove to be distinguishable. The only previous comprehensive study of megaspore occurrences throughout the Pennsylvania]! of North America is that by Cross (1947) on the spore floras of West Virginia and Kentucky. Using Cross' chart (1947, fig. 2, p. 287), showing spore distri- bution for West Virginia and Kentucky, some general comparisons can be made with the megaspore occurrences known from Illinois coals. Cross found smooth aphanozonate spores (in particular those of Triletes glabratus, s. 1.) in the Lower War Eagle Coal and a few coals in the upper part of the Potts- ville Series, but they seem to occur with some regularity, from coal to coal, in and above the Upper Freeport Coal. These oc- currences parallel the marked abundance of these spores in the upper part of the Car- bondale Group and in the McLeansboro Group of Illinois. Spinose lageniculate spores apparently are found in some coals of the Pottsville Series but are not known to occur above the No. 5 Block Coal in the lower part of the Allegheny Series. In Illinois, distinctly spinose lageniculate spores are unknown above the Tarter Coal of the Tradewater Group. Smooth lageniculate spores of the Triletes rugosus (s. 1.) type occur with regularity in the upper coals of the Potts- ville Series. This also may parallel their sudden occurrence in, and more or less common occurrence above, the coals of the upper part of the Tradewater Group. Spores similar to those described as T. levis and questionably referred in this report to the section Lagenicula were reported by Cross from the Waynesburg Coal in the up- per part of the Monongahela Series. Dijk- stra (1958) reported similar spores from the Lawrence Shale of Kansas. These spores are typical of the upper portion of the McLeansboro Group in Illinois. Zonate megaspores are not known with certainty above the No. 5 Block Coal; their most common occurrences appear to be re- stricted to the Pottsville Series. These spores are not known from Illinois coals above the top of the Tradewater Group. Triangulate and auriculate megaspores occur sporadically from the Cedar Grove Coal in the Pottsville Series throughout the Pennsylvanian of West Virginia and Ken- tucky. These megaspores also occur, more or less, throughout the Pennsylvanian of Illinois. Cross also noted the presence of spores of genera other than Triletes. He did not record the presence of Cystosporites above the Pittsburgh Coal at the base of the Mo- nongahela Series. The genus occurs through upper Mississippian and most of the Penn- sylvanian of Illinois, but is not represented in the upper portion of the McLeansboro Group. Monoletes is reported only from the Buffalo Creek and Coalburg Coals of the Pottsville Series although it is repre- sented in most of the coals in the Pennsyl- vanian of Illinois. Spores, probably of Spencerisporites , are noted as occurring up to the lower part of the Allegheny Series. The genus is represented sporadically throughout the Illinois Pennsylvanian. More detailed comparisons and conclu- sions are left to the reader. These will nec- essarily vary depending on each individ- ual's opinion on the circumscription of the various taxa. As more studies on both small and large spores are completed, a clearer total picture of floral elements and their areal and stratigraphic distribution should emerge. 96 ILLINOIS STATE GEOLOGICAL SURVEY REFERENCES Arnold, C. A., 1938, Note on a lepidophyte stro- bilus containing large spores, from Braid- wood, Illinois: Am. Midland Naturalist, v. 20, no. 3, p. 709-712. Arnold, C. A., 1944, A heterosporous species of Bowmanites from the Michigan Coal Basin: Am. Jour. Botany, v. 31, no. 8, p. 466-469. Arnold, C. A., 1948, Some cutinized seed mem- branes from the coal-bearing rocks of Michi- gan: Torrey Bot. Club Bull., v. 75, no. 2, p. 131-146. Arnold, C. A., 1950, Megaspores from the Michigan Coal Basin: Michigan Univ., Mus. Paleon- tology Contr., v. 8, no. 5, p. 59-111. Bailey, W. F., 1936, Micropaleontology and stratig- raphy of the Lower Pennsylvanian of central Missouri: Jour. Paleontology, v. 9, no. 6, p. 483-502. Bartlett, H. H., 1929, Fossils of the Carboniferous coal pebbles of the glacial drift at Ann Ar- bor: Michigan Acad. Sci., Arts, and Letters Papers, v. 9 (1928), p. 11-28. Bennie, James, and Kidston, Robert, 1886, On the occurrence of spores in the Carboniferous Formation of Scotland: Royal Physical Soc. Edinburgh Proc, v. 9, p. 82-117. Bhardwaj, D. C, 1955, The spore genera from the Upper Carboniferous coals of the Saar and their value in stratigraphical studies: Palaeo- botanist, v. 4, p. 119-149. Bhardwaj, D. C, 1957, The spore flora of Velener Schichten (Lower Westphalian D) in the Ruhr Coal Measures: Palaeontographica, Abt. B, Bd. 102, Lief. 4-5, p. 110-138. Bochenski, Tadeusz, 1936, liber Sporophyllstande (Bliiten) einiger Lepidophyten aus dem pro- duktiven Karbons Polens: Ann. Geol. Soc. Pologne, t. 12, p. 193-240. Cady, G. H., 1952, Minable coal reserves of Illinois: Illinois Geol. Survey Bull. 78, 138 p. Chaloner, W. G., 1951, On Spencerisporites, gen. nov., and S. karczewskii (Zerndt), the isolated spores of Spencerites insignis Scott: Ann. and Mag. Nat. History, ser. 12, v. 4, p. 861-873. Chaloner, W. G., 1952, On Lepidocarpon waltoni, sp. n., from the Lower Carboniferous of Scotland: Ann. and Mag. Nat. History, ser. 12, v. 5, p. 572-582. Chaloner, W. G„ 1953a, A new species of Lepido- strobus containing unusual spores: Geol. Mag., v. 90, no. 2, p. 97-110. Chaloner, W. G., 1953b, On the megaspores of four species of Lepidostrobus: Ann. of Botany, new ser., v. 17, no. 66, p. 263-293. Chaloner, W. G., 1953c, On the megaspores of Sigillaria: Ann. and Mag. Nat. History, ser. 12, v. 6, p. 881-897. Chaloner, W. G., 1954a, Notes on the spores of two British Carboniferous lycopods: Ann. and Mag. Nat. History, ser. 12, v. 7, p. 81-91. Chaloner, W. G., 1954b, Mississippian megaspores from Michigan and adjacent states: Michigan Univ., Mus. Paleontology Contr., v. 12, no. 3, p. 23-35. Chaloner, W. G., 1956a, On Sporangiostrobus lang- fordi, sp. nov., a new fossil lycopod cone from Illinois: Am. Midland Naturalist, v. 55, no. 2, p. 437-442. Chaloner, W. G., 1956b, Triletes palaeocristatus Chaloner, new name: Micropaleontology, v. 2, no. 3, p. 298. Chaloner, W. G., 1958a, A Carboniferous Selaginel- lites with Densosporites microspores: Palae- ontology, v. 1, pt. 3, p. 245-253. Chaloner, W. G., 1958b, Polysporia mirabilis New- berry, a fossil lycopod cone: Jour. Paleon- tology, v. 32, no. 1, p. 199-209. Chaloner, W. G., 1958c, Isolated megaspore tetrads of Stauropteris burntislandica: Ann. of Bot- any, new ser., v. 22, no. 86, p. 197-204. Christensen, Brorson, 1954, New mounting media for pollen grains: Danmarks geol. Under- s0gelse, ser. 2, no. 80, p. 7-11. Cooper, C. L., 1942, Occurrence and stratigraphic distribution of Paleozoic ostracodes: Jour. Paleontology, v. 16, no. 6, p. 764-776; re- printed as Illinois Geol. Survey Rept. Inv. 83. Cropp, F. W., 1956, Pennsylvanian spore floras from the Warrior Basin, Mississippi and Ala- bama: unpublished Master's thesis, Univ. of Illinois. Cross, A.T., 1947, Spore floras of the Pennsylvanian of West Virginia and Kentucky: Jour. Ge- ology, v. 55, no. 3, p. 285-308. Dijkstra, S. J., 1946, Eine monographische Bear- beitung der karbonischen Megasporen: Me- dedeel. van de Geol. Stichting, Ser. C-III-1- No. 1, p. 1-101. Dijkstra, S. J., 1949, La signification stratigra- phique des spores: 75e anniversaire Soc. geol. Belgique, t. 72, fasc. special 1949, p. B493- B498. Dijkstra, S. J., 1950, Carboniferous megaspores in Tertiary and Quaternary deposits of S. E. England: Ann. and Mag. Nat. History, ser. 12, v. 3, p. 865-877. Dijkstra, S. J., 1952a, New Carboniferous mega- spores from Turkey; Ann. and Mag. Nat. History, ser. 12, v. 5, p. 102-104. Dijkstra, S. J., 1952b, Megaspores of the Turkish Carboniferous and their stratigraphical value: Internat. Geol. Congress, Rept. 18th Sess., Great Britain, 1948, Part X, p. 11-17. Dijkstra, S. J., 1952c, The stratigraphical value of megaspores: 3eme Congres de Strat. et de Geol. du Carbonifere, Heerlen, 1951, Compte rendu, t. 1, p. 163-168. Dijkstra, S. J., 1955a, Megasporas carboniferas espanolas y su empleo en la correlaci6n estratigrafica: Estudios Geol6gicos, t. 11, nr. 27, 28, p. 277-354. REFERENCES 97 Dijkstra, S. J., 1955b, The megaspores of the West- phalian D and C: Mededeel. van de Geol. Stichting, nieuwe ser., no. 8, p. 5-11. Dijkstra, S. J., 1955c, La correlation des veines de charbon par les megaspores: Ass. £tud. Paleont. Pub., no. 21, hors ser., p. 107-119. Dijkstra, S. J., 1956, Some Brazilian megaspores, Lower Permian in age, and their comparison with Lower Gondwana spores from India: Mededeel. van de Geol. Stichting, nieuwe ser., no. 9, 1955, p. 5-10. Dijkstra, S. J., 1957, Lower Carboniferous mega- spores: Mededeel. van de Geol. Stichting, nieuwe ser., no. 10, 1956, p. 5-18. Dijkstra, S. J., 1958, On a megaspore-bearing ly co- pod strobilus: Acta Bot. Neerlandica, v. 7, no. 2, p. 217-222. Doehler, R. W., 1957, Variation in the mineral composition of underclays — its causes and significance: unpublished doctoral thesis, Univ. of Illinois. Dunbar, C. O., and Henbest, E. G., 1942, Pennsyl- vanian Fusulinidae of Illinois: Illinois Geol. Survey Bull. 67, 218 p. Eisenack, Alfred, 1956, Beobachtungen an Frag- menten von Eurypteriden-Panzern: Neues Jahrb. Geol. u. Palaont., Abh. 104, Heft 2, p. 119-128. Felix, C. J., 1954, Some American arborescent ly- copod fructifications: Ann. Missouri Bot. Garden, v. 41, no. 4, p. 351-394. Guennel, G. K., 1952, Fossil spores of the Alle- ghenian coals in Indiana: Indiana Geol. Survey Rept. Prog. 4, p. 1-40. Guennel, G. K., 1954, An interesting mesgaspore species found in Indiana Block Coal: Butler Univ. Bot. Studies, v. 11, p. 169-177. Harris, T. M., 1956, The fossil plant cuticle: En- deavour, v. 15, no. 60, p. 210-214. Henbest, O. J., 1933, Plant residues of Coal No. 6: Illinois Acad. Sci. Trans., v. 25, no. 4, p. 147-149. Henbest, O. J., 1935, Size and ornamentation of some modern and fossil lycopod spores: Illi- nois Acad. Sci. Trans., v. 28, no. 2, p. 91-92. H0eg, O. A., Bose, M. N., and Manum, Svein, 1955, On double walls in fossil megaspores, with description of Duosporites congoensis, n. gen., n. sp.: Nytt Magasin for Botanikk, v. 4, p. 101-107. Hoffmeister, W. S., Staplin, F. L., and Malloy, R. E., 1955, Mississippian plant spores from the Hardinsburg Formation of Illinois and Kentucky: Jour. Paleontology, v. 29, no. 3, p. 372-399. Horst, Ulrich, 1955, Die Sporae dispersae des Xamurs von Westoberschlesien und Mahr- isch-Ostrau: Palaeontographica, Abt. B, Bd. 98, Lief. 4-6, p. 137-236. Hoskins, J. H., and Abbott, M. L., 1956, Selaginel- lites crassicinctus, a new species from the Desmoinesian Series of Kansas: Am. Jour. Botany, v. 43, no. 1, p. 36-46. Ibrahim, A. C, 1932, Beschreibung von Sporen- formen aus Floz Agir, in Potonie, Robert, Sporenformen aus den Flozen Agir und Bis- marck des Ruhrgebietes: Neues Jahrb., Beilage-Band 67, Abt. B, p. 447-449. Ibrahim, A. C, 1933, Sporenformen des Aegirhori- zonts des Ruhr-Reviers: Konrad Triltsch, Wiirzburg, 47 p. Kalibova, Milada, 1951, Megaspores of the Rad- nice Coal Measure Zone of the Kladno- Rakovnik coal basin: Geol. Survey Czecho- slovakia, v. 18 (Paleontology), p. 21-63. Kosanke, R. M., 1947, Plant microfossils in the cor- relation of coal beds: Jour. Geology, v. 55, no. 3, p. 280-284; reprinted as Illinois Geol. Survey Circ. 131. Kosanke, R. M., 1950, Pennsylvanian spores of Illi- nois and their use in correlation: Illinois Geol. Survey Bull. 74, 128 p. Kosanke, R. M., 1954, Correlations of coals and spore analysis: Univ. Missouri School of Mines and Metall. Bull., tech. ser., no. 85, p. 11-16. Kowalewska-Maslankiewtczowa, Zofja, 1932, Meg- asporen aus dem Floz "Elzbieta" in Siersza: Acta Soc. Bot. Poloniae, Bd. 9 (supp.), p. 155-174. Krfmp, G. O. W., 1955, Stratigraphic correlations in Paleozoic horizons with help of plant spores and pollen: Penn. State Univ. Min- eral Industries Exp. Sta. Bull., no. 68. Kubart, Bruno, 1910, Untersuchungen tiber die Flora des Ostrau-Karwiner Kohlenbeckens. I. Die Spore von Spencerites membranaceus, nov. spec: Akad. Wiss., Wien, Math.-natur- wiss. Kl., Denkscht., v. 85, p. 83-89. I amar, J. E., 1925, Geology and mineral resources of the Carbondale quadrangle: Illinois Geol. Survey Bull. 48, 172 p. Lanjouw, Joseph (Ed.), 1956, International code of botanical nomenclature, regnum vege- table, v. 8, Internat. Bur. for Plant Tax- onomy and Nomenclature, Utrecht, 338 p. Loose, Friedrich, 1932, Beschreibung von Sporen- formen aus Floz Bismarck, in Potonie, Rob- ert, Sporenformen aus den Flozen Agir und Bismarck des Ruhrgebietes: Neues Jahrb., Beilage-Band 67, Abt. B, p. 449-452. Loose, Friedrich, 1934, Sporenformen aus dem Floz Bismarck des Ruhrgebietes: Arb. Inst. fur Palaobot. und Petrog. der Brennsteine, Bd. 4, p. 126-164. McCabe, L. C, 1931, Some plant structures of coal: Illinois Acad. Sci. Trans., v. 24, no. 2, p. 321- 326. McCabe, L. C, 1933, The lithological and botanical constituents of Coal No. 6 at Nashville, Illi- nois: unpublished doctoral thesis, Univ. of Illinois. Moore, R. C, et al., 1944, Correlation of Pennsvl- vanian formations of North America: Geol. Soc. America Bull., v. 55, p. 657-706. 98 ILLINOIS STATE GEOLOGICAL SURVEY Nowak, J., and Zerndt, J., 1936, Zur Tektonik des ostlichsten Teils des Polnischen Stein- kohlenbeckens: Bull. Intern. Acad. Polon. Sci., ser. A, p. 56-73. Pierart, Pierre, 1956, Quelques megaspores con- tenues dans les charbons stephaniens des bassins de Blanzy et de Decazeville: Bull, de la Soc. beige de Geol., de Paleontol. et d'Hydrol., t. 64 (1955), fasc. 3 et dernier, p. 587-599. Pierart, Pierre, 1957, Note preliminaire sur les megaspores du Westphalien C superieur en Campine beige: Palaont. Zeitschr., Bd. 31, Nr. 1 and 2, p. 46-52. Potonie, Robert, 1954a, Stellung der palaozoischen Sporengattungen in natiirlichen System: Palaont. Zeitschr., Bd. 28, Heft 3-4, p. 103- 139. Potonie, Robert, 1954b, Les spores des plantes paleozoiques dans les systeme naturel (raor- phologique): Lejeunia, Rev. de Bot., t. 18, p. 5-20. Potonie, Robert, and Kremp, Gerhard, 1954, Die Gattungen der palaozoischen Sporae dis- persae und ihre Stratigraphie: Geol. Jahrb., Bd. 69, p. 11-194. Potonie, Robert, and Kremp, Gerhard, 1955, Die Sporae dispersae des Ruhrkarbons, ihre Mor- phographie und Stratigraphie mit Ausblick en auf Arten anderer Gebiete und Zeit- abschnitte - Teil I: Palaeontographica, Abt. B, Bd. 98, Lief. 1-3, p. 1-136. ' Potonie, Robert, and Kremp, Gerhard, 1956, Die Sporae dispersae des Ruhrkarbons, ihre Morphographie und Stratigraphie mit Aus- blicken auf Arten anderer Gebiete und Zeit- abschnitte - Teil II: Palaeontographica, Abt. B, Bd. 99, Lief. 4-6, p. 85-191. Read, C. B., 1947, Pennsylvanian floral zones and floral provinces: Jour. Geology, v. 55, no. 3, p. 271-279. Remy, Winfried, and Remy, Renate, 1956, Noeg- gerathiostrobus vicinalis E. Weiss und Be- merkungen zu ahnlichen Fruktifikationen: Deutsch. Akad. Wiss., Berlin, Kl. Chem., Geol., u. Biol., Jahrg. 1956, Nr. 2, p. 1-11. Rexroad, C. B., 1957, Conodonts from the Chester Series in the type area of southwestern Illi- nois: Illinois Geol. Survey Rept. Inv. 199, 43 p. Sahabi, Yadollah, 1936, Recherches sur les spores des houilles franchises: Dissertation, Lille, p. 1-59. Schemel, M. P., 1950a, Carboniferous plant spores from Daggett County, Utah: Jour. Paleon- tology, v. 24, no. 2, p. 232-244. Schemel, M. P., 1950b, Cretaceous plant microfos- sils from Iowa: Am. Jour. Botany, v. 37, no. 9, p. 750-754. Schopf, J. M., 1936a, The paleobotanical signifi- cance of plant structure in coal: Illinois Acad. Sci. Trans., v. 28, no. 2, p. 106-110. Schopf, J. M., 1936b, Spores characteristic of Illi- nois Coal No. 6: Illinois Acad. Sci. Trans., v. 28, no. 2, p. 173-176. Schopf, J. M., 1938, Spores from the Herrin (No. 6) Coal bed in Illinois: Illinois Geol. Survey Rept. Inv. 50, 73 p. Schopf, J. M., 1941a, Contribution to Pennsylva- nian paleobotany - Notes on the Lepidocar- paceae: Am. Midland Naturalist, v. 25, no. 3. p. 548-563; reprinted as Illinois Geol. Sur- vey Circ. 73. Schopf, J. M., 1941b, Contributions to Pennsylva- nian paleobotany - Mazocarpon oedipternum, sp. nov., and sigillarian relationships: Illi- nois Geol. Survey Rept. Inv. 75, 53 p. Schopf, J. M., 1948, Pteridosperm male fructifica- tions; American species of Dolerotheca, with notes regarding certain allied forms: Jour. Paleontology, v. 22, no. 6, p. 681-724; re- printed as Illinois Geol. Survev Rept. Inv. 142. Schopf, J. M., 1949, Research in coal paleobotany since 1943: Econ. Geology, v. 44, no. 6, p. 492-513. Schopf, J. M., Wilson, L. R., and Bentall, Ray, 1944, An annotated synopsis of Paleozoic fos- sil spores and the definition of generic groups: Illinois Geol. Survey Rept. Inv. 91, 72 p. Schulze, Franz, 1855, tJber das Vorkommen wohl- erhaltener Cellulose in Braunkohle und Steinkohle: K. preuss. Akad. Wiss., Berlin, Math.-phys. Kl., Sitzungsber., p. 676-678. Scott, D. H., 1898, On the structure and affinities of fossil plants from the Paleozoic rocks. II. On Spencerites. a new genus of lycopodi- aceous cones from the Coal Measures, found- ed on the Lepidodendron spenceri of Wil- liamson: Royal Soc. London Philos. Trans., ser. B, 1897, v. 189, p. 83-106. Siever, Raymond, 1951, The Mississippian-Pennsyl- vanian unconformity in southern Illinois: Am. Assoc. Petroleum Geologists Bull., v. 35, no. 3, p. 542-581; reprinted as Illinois Geol. Survey Rept. Inv. 152. Sittler, C, 1955, Methodes et techniques physico- chimiques de preparation des sediments en vue de leur analyse pollinique: Inst, francais petrole Rev. et Annales combustibles liq- uides, v. 10, no. 2, p. 103-114. Stach, E., and Zerndt, Jan, 1931, Die Sporen in dem Flamm-, Gasflamm-, und Gas-kohlen des Ruhrkarbons: Gliickauf, Jahrg. 67, Nr. 35, p. 1118-1124. Surange, K. R., 1952, The morphology of Staurop- teris burntislandica P. Bertrand and its megasporangium, Bensonites fusiformis R. Scott: Royal Soc. London Philos. Trans., ser. B., v. 237, no. 642, p. 73-91. REFERENCES 99 Swann, D. H., and Atherton, Elwood, 1948, Sub- surface correlations of lower Chester strata of the Eastern Interior Basin: Jour. Geology, v. 56, no. 4, p. 269-287; reprinted as Illinois Geol. Survey Rept. Inv. 135. Wanless, H. R., 1939, Pennsylvanian correlations in the Eastern Interior and Appalachian coal fields: Geol. Soc. America Spec. Paper 17, 130 p. Wanless, H. R., 1947, Regional variations in Penn sylvanian lithologv: Jour. Geology, v. 55. no. 3, p. 237-253. Wanless, H. R., 1955, Pennsylvanian rocks of East- ern Interior Basin: Am. Assoc. Petroleum Geologists Bull., v. 39, no. 9, p. 1753-1820. Wanless, H. R., 1956, Classification of the Penn- sylvanian rocks of Illinois as of 1956, with correlation chart compiled bv Raymond Siever: Illinois Geol. Survey Circ. 217, 14 p. Wanless, H. R., and Weller, J. M., 1932, Correla- tion and extent of Pennsylvanian cvclo- thems: Geol. Soc. America Bull., v. 43, p. 1003-1016. Weller, J, M., 1930, Cyclical sedimentation during the Pennsylvanian period and its signifi- cance: Jour. Geology, v. 38, p. 97-135. Weller, J. M., 1945, Geologic map of Illinois, Illi- nois Geol. Survey. Weller, J. M., Henbest, L. G., and Dunbar, C. O.. 1942, in Dunbar, C. O., and Henbest, L. G.. Pennsylvanian Fusulinidae of Illinois: Illi- nois Geol. Survey Bull. 67, p. 9-28. Wicher, C. A., 1934a, Sporenformen der Flamm- kohle des Ruhrgebietes: Arb. Inst, fur Pa- laobot. und Petrog. der Brennsteine. Bd. 4. p. 165-212. Wicher, C. A., 1934b, Dber Abortiverscheinungen bei fossilen Sporen und ihre phylogenetische Bedeutung: Arb. Inst, fiir Palaobot. und Petrog. der Brennsteine, Bd. 5, p. 87-95. Williamson, W. C, 1879, On the organization of the fossil plants of the Coal Measures, Part IX: Royal Soc. London Philos. Trans., 1878, v. 169, pt. 2, p. 319-364. Williamson, W. C, 1894, On the organization of the fossil plants of the Coal Measures, Part XIX: Royal Soc. London Philos. Trans., ser. B., 1893, v. 184, p. 1-38. Wills, L. J., 1959, The external anatomv of some Carboniferous "Scorpions," Part I: Palaeon- tology, v. 1, pt. 4, p. 261-282. Wilson, L. R., and Hoffmeister, W. S., 1956, Plant microfossils of the Croweburg coal: Okla- homa Geol. Survey Circ. 32, 57 p. Witham, H. T. M., 1833', The internal structure of fossil vegetables found in the Carboniferous and oolitic deposits of Great Britain: Adam and Charles Black, Edinburgh, and Long- man, Rees, Orme, Crown, Green, and Long- man, London, 84 p. Wodi house, R. P., 1935, Pollen grains, their struc- ture, identification, and significance in sci- ence and medicine, 1st ed., McGraw-Hill Book Company, Inc., New York, 574 p. Workman, L. E., Swann, D. H., and Atherton, Elwood, 1950, Summary of stratigraphy shown in geologic cross section of Illinois Basin: Illinois Geol. Survey Circ. 160, 14 p. Zerndt, Jan, 1930a, Petrograficzne badania wegla z pokladu "Izabcla" w Trzebini: Przeglad Gorniczo-Hutniczy, t. 22, no. 1 (444), p. 5-8. Zerndt, Jan, 1930b, Megasporen aus Isabella-Floz (Schichten v. Laziska) in Trzebini: Ann. Soc. Geol. Pologne, Annee 1929, t. 6, p. 302- 313. Zerndt, Jan, 1930c, Megasporen aus einem Floz in Libi^z (Stephanien): Bull. Intern. Acad. Polon. Sci., ser. B (1), Annee 1930, p. 39-70. Zerndt, Jan, 1930d, Triletes giganteus, n. sp., eine riesige Megaspore aus dem Karbon: Bull. Intern. Acad. Polon. Sci., ser. B (1), Annee 1930, p. 71-79. Zerndt, Jan, 1931, Megasporen als Leitfossilien des produktiven Karbons: Bull. Intern. Acad. Polon. Sci., ser. A, Annee 1931, p. 165-183. Zerndt, Jan, 1932a, Megasporen aus dem Zwickauer und Lugau-Olsnitzer Karbon: Jahrb. f. d. Berg.- und Hiittenw, in Sachsen, Jahrg. 1932, p. A9-A16. Zerndt, Jan, 1932b, Versuch einer stratigraphischen Bestimmung von Steinkohlen-Gerollen der Karpaten auf Grund von Megasporen studien: Bull. Intern. Acad. Polon. Sci., ser. B (1), p. 1-7. Zerndt, Jan, 1934, Les megaspores du bassin houiller Polonais, Partie I: Acad. Polon. Sci., Trav. Geol., no. 1, p. 1-56. Zerndt, Jan, 1937a, Les megaspores de bassin houiller Polonais, Partie II: Acad. Polon. Sci., Trav. Geol., no. 3, p. 1-78. Zerndt, Jan, 1937b, Megasporen aus dem Westfal und Stefan in Bohmen: Bull. Intern. Acad. Polon. Sci., ser. A, p. 583-599. Zerndt, Jan, 1938a, Die Eignung von Megasporen als Leitfossilien: 2eme Congres de Strat. et de Geol. du Carbonifere, Heerlen, 1935, Compte rendu, t. 3, p. 1711-1732. Zerndt, Jan, 1938b, Yertikale Reichweite von Meg- asporentypen im Karbon des Bassin du Xord: Ann. Soc. Geol. Pologne, t. 13, Annee 1937, p. 21-30. Zerndt, Jan, 1940, Megasporen des Saarkarbons: Palaeontographica, Abt. B, Bd. 84, p. 133- 150. 100 ILLINOIS STATE GEOLOGICAL SURVEY + < X o o h- Z) m cr co Q cr o Q_ C/) SN0I1 -Vd30VlM CD o sj- to — CD in o rO O - CD * * * * * < & JO u> * 4 CD CD CD CD O CD 0> I * ifiOm CD CD CM CD rt- m =• to z (sauas J8|S8L|0) SNOIlVlMdOJ ao (UDIUDA -|AsUU3d) saaa ivoo . cr = UJ _| . is O CD CD u r ouj soiri ir CO < O _J CO 5 O " CE ~ _ LlI x <* < O u. = z CO 2 u z in — C\J o «> ~q 6 CT O J jZU ^xfe jx1 cr < it 2 _j U (T Q. DO X CD CO CO O .8UJ o > -J > 5 9§2 a> O _ CC co co oil- i2>> -Q LU CD X X O Z Q CL 0- -J o _i § gc cr < t- < LU => 3 R co cd z S 5 Q * Z LU < LU jtCQ CO u o - o b^ LU $ O 0 I z ,n ^ ° «0 uj _| Ij t- >- j cr m s < < 5 P CD dnoa< oaoasNV3i ow 31VC) -Noaavo a31VM3QVai W31SAS NVI N\7A~I AS NN 3d SPORE DISTRIBUTION CHART 101 •< 2: <* o • 2 " 3 - 5 o O 2 2 2 MISSISSIPPIAN (CHESTER SERIES) NEW DESIGN HOM- BERG i en ^ o co m ELVIRA CASEYVILLE > m m 33 si co0 CO -H * * * oj * — 00 O — I I CD r\> ooocdcd ^ * g * -n| ^1 ->J CD CJt CD CDCDCT) tD CO tf> CD O 00 OOO- oo -vi en en to -^ cn cn-NiO° E B c 0, en — & - U £ — B B ed 0 0- eu n z t/i J=. bfi a 3 0 — — B ed ed B <1 X B CM > B ^ 0 B B RJ U CJ s- u (M = c B c cd •~ c B U fl ( •« rv ■d s be 0 B x ^ if 43 0 Oh — - y: s 2 ed g 1 B OJ C = h u H c X - a. H t« *> K o ~^ ^ U GENUS SPECIES CYSTOSPORITES C giganteus C. verrucosus C. varius C. breretonenis C. sp. ♦ ♦ ♦■ SECTION LAGENICULA LAGENICULA? NO SECTIONAL ASSIGNMENT ZONALES TRIANGULATI { APHAN0Z0NAT AURICULATI T crassiaculeatus ' T. subpilosus T. subpilosus forma major ; T. horndus T. rugosus T. levis T.l nudus in Schopf (1938) T. indianensisi T. splendid us* T. echinoides T. globosus T globosus war. (A) T. globosus var. (B) T. globosus var. (C)' T. cf. T hirsutus T praetextus • T. rotatus T. romosus T superbus T. brasserti t T triangulatus T mamillarius T. glabratus T. auntus T. augustae T (Aunculati) spp ♦ ♦ TRILETES1 7"? corycilisx T. ? saturmpunctatus CALAMOSPORA C. spp. C. cf. C laevigata C. cf. C smuosa ' SPENCERISPORI TES S cf S. radiatus n.comb 5. cf. S. gracilis n.comb. M0N0LETE5 M. spp. RENISPORITESn gen R confossus ' n. sp. PUNCTATISPORITES P. cf P obe*. PARASPORITES P spp. ♦ ♦ PLATES AND EXPLANATIONS [103 PLATE 1 All specimens photographed with transmitted light. Color of filter, when used, indicated. Triletes subpilosus forma major (Dijkstra) ex Chaloner p. 18 Figure 1. Characteristic lateral compression with lips partially torn. Total length 1610 u. Maceration 943 slide 5, coal in the Bethel (Mooretown) Forma- tion, Hardin County, Kentucky. Red filter, same scale as figure 8, (x30). 2a. Smaller spore with more delicate spines. Slightly oblique compression. Maceration 943 slide 6, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Red filter, same scale as figure 8, (x30). 2b. Same spore, detail of spines. Same scale as figures 4, 7b, (X150). 3. Spore with strap-like (preservational?) spines. Slightly oblique com- pression. Maceration 943 slide 6, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Red filter, same scale as figure 8, (X30). 4. Closely spaced spines of small immature spore. Spines about 154 p in length with cup-shaped terminations. Maceration 943 slide 9, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Scale indicated below figure, (X150). 5. Broken spore. Spines up to 124 n in length. Maceration 943 slide 12, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Red filter, same scale as figures 4, 7b, (xl50). 6. Partially broken spore. Lateral compression. Total length 1480 p. Spines sharper, more delicate, and more closely spaced towards apex. Maceration 810 slide 11, coal in the Hardinsburg Formation, Critten- den County, Kentucky. Red filter, same scale as figure 8, (x30). 7a. Lateral compression. Total length 1385 /*. Maceration 166 slide XXII (5. 6. 7), coal in Hardinsburg Formation, Johnson County, Illinois. Red filter, same scale as figure 8, (x30). 7b. Same spore, detail of spines. Red filter, scale indicated above figure, (xl 50). 8. Lateral compression. Total length 1170/*. Maceration 687A slide 1, coal in the Vienna Formation, Johnson County, Illinois. Red filter, scale indicated below figure, (x30). 9. Spines about 124 /x in length. Maceration 200 slide 2, in Degonia For- mation, Pope County, Illinois. Red filter, same scale as figures 4, 7b, (X150). 04 Illinois State Geological Survey Bulletin 8(5, Plate Winslow — Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 86, Plate 2 400/J. Winslow — Mississippi n-Pennsylvani an Spores PLATE 2 All specimens photographed with transmitted light. Color of filter, when used, indicated. Triletes subpilosus (Ibrahim) Schopf, Wilson, and Bentall (sensu Dijkstra) . p. 17 Figure 1. Proximo-distal compression. Diameter 840 p. Maceration 795 slide 6, coal in Caseyville Group, Wabash County, Illinois. Red filter, scale in- dicated below figure, (x40). 2. Lateral compression. Apical prominence and contact area spines characteristically developed. Maceration 795 slide 4, coal in Caseyville Group, Wabash County, Illinois. Red filter, same scale as figure 1, (X40). 3. Lateral compression. Width 940 jx. Maceration 795 slide RMK, coal in Caseyville Group, Wabash County, Illinois. Red filter, same scale as figure 1, (x40). 4. Detail of stout spines. Maceration 587 slide 3, Battery Rock Coal, Har- din County, Illinois. Red filter, same scale as figure 5, (xl50). 5. More delicate spines. Maceration 797 slide 3, coal in Casevville Group, Wabash County, Illinois. Red filter, scale indicated below figure, (X150). Triletes horridus (Zerndt) Schopf, Wilson, and Bentall (sensu Dijkstra) . . p. 20 6. Side view of large and subsidiary spines. Maceration 200 slide 3, in Degonia Formation, Pope County, Illinois. Red filter, same scale as figure 5, (X150). 7. Lateral compression with delicate spines. Total length 1045 fi. Macera- tion 905 slide 2, "Makanda" Coal, Jackson County, Illinois. Red filter, same scale as figure 1, (x40). 8. Proximo-distal compression. Diameter 920 (U. Maceration 905 slide 2, "Makanda" Coal, Jackson County, Illinois. Red filter, same scale as figure I, (X40). 9. Characteristic lateral compression. Total length 1010^. Maceration 905 slide 2, "Makanda" Coal, Jackson County, Illinois. Red filter, same scale as figure 1, (x40). 10. Lateral compression. Smaller spore with more closely spaced spines, but with apical prominence of normal size. Total length 865 p. Maceration 907 slide 6, '"Makanda" Coal, Jackson County, Illinois. Red filter, same scale as figure 1, (x40). 11. Detail of characteristically developed well preserved spines. Small subsidiary spines present. Maceration 796 slide 6, coal in Casevville Group, Wabash County, Illinois. Red filter, same scale as figure 5, (X150). 12. Detail of slightly worn spines. Small subsidiary spines present. Macera- tion 905 slide 2, "Makanda" Coal, Jackson County, Illinois. Red filter, same scale as figure 5, (xl50). [107 PLATE 3 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes horridus (Zerndt) Schopf, Wilson, and Bentall (sensu Dijkstra) . p. 20 Figure 1. Slightly oblique compression. Maceration 914 slide 2, Tarter Coal, Mercer County, Illinois. Reflected light, same scale as figure 12, (x40). Triletes crassiaculeatus (Zerndt) Schopf, Wilson, and Bentall p. 21 2. Lateral compression. Lips partially torn away. Total length 2155 /*. Maceration 943 slide 2, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Reflected light, scale indicated below figure, (x20). 3. Spines up to 288 ^ in length. Maceration 943 slide 9, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Red filter, scale indicated at right of figure, (X150). Triletes rugosus (Loose) Schopf (sensu Dijkstra) p. 22 4. Slightly oblique compression. Greatest dimension 645 /*. Spore coat thin. Maceration 599B slide 5, Rock Island (No. 1) Coal, Fulton County, Illinois. Same scale as figure 9, (X50). 5. Slightly oblique proximo-distal compression. Diameter 895 p. Macera- tion 825 slide 3, Colchester (No. 2) Coal, Schuyler County, Illinois. Red filter, same scale as figure 9, (x50). 6. Small example. Diameter 410^. Maceration 599B slide 7, Rock Island (No. 1) Coal, Fulton County, Illinois. Scale indicated below figure, (X100). 7. Lateral compression. Spore coat ornamented with small spines. Great- est dimension 950 /x. Maceration 599B slide 5, Rock Island (No. 1) Coal, Fulton County, Illinois. Red filter, same scale as figure 9, (x50). 8. Lateral compression. Lips open. Arcuate ridges well defined. Total length 955 /*. Maceration 825 slide 3, Colchester (No. 2) Coal, Schuyler County, Illinois. Red filter, same scale as figure 9, (x50). 9. Oblique compression. Lips open. Maceration 915 slide 3, Murphys- boro (?) Coal, Williamson County, Illinois. Scale indicated below figure, (x50). Triletes levis (Zerndt) Schopf, Wilson, and Bentall p. 24 10. Lateral compression of small example with relatively thick arcuate ridges and prominent trilete rays. Total length 445 fi. Maceration 600 slide 8, "LaSalle" Coal, Bureau County, Illinois. Scale indicated at left of figure, (X80). 11. Typical lateral compression. Total length 710 /i. Maceration 703 slide 1, "Woodbury" Coal, Cumberland County, Illinois. Reflected light, same scale as figure 12, (x40). 12. Lateral compression with inner membrane. Total length 1305 /x. Mac- eration 136, Friendsville (?) Coal, Wabash County, Illinois. Red filter, scale indicated at left of figure, (x40). 13. Lateral compression with characteristic outline. Contact areas rela- tively large. Apical prominence dense. Total length 1400 fx. Maceration 136, Friendsville (?) Coal, Wabash County, Illinois. Red filter, same scale as figure 12, (x40). 14. Lateral compression. Spore coat ornamented with small tubercles. Lips split apart midway between their extremities and apex. Total length 1175^. Maceration 148, "Watson" Coal, Effingham County, Illinois. Red filter, same scale as figure 12, (x40). [108 Illinois State Geological Survey Bulletin 86, Plate 3 Winslow — Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 86, Plate 4 Winslow— Mississippian-Pennsylvanian Spores PLATE 4 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes globosus Arnold var. (A) p. 43 Figure 1. Proximo-distal compression. Radiating ridges vaguely developed on contact areas. Diameter 480 /x. Maceration 810 slide 12, coal in the Hardinsburg Formation, Crittenden County, Kentucky. Reflected light, scale indicated below figure, (x50). 2. Characteristic proximo-distal compression. Diameter 495 /x. Macera- tion 810 slide 2, coal in the Hardinsburg Formation, Crittenden County, Kentucky. Red filter, same scale as figure 6, (xlOO). 3. Maximum spine development observed. Spines up to 22 /x in length. Maceration 810 slide 7, coal in the Hardinsburg Formation, Critten- den County, Kentucky. Green filter, scale indicated below figure, (X150). Triletes globosus Arnold var. (B) p. 44 4. Lateral half of spore showing spinose contact area and lips. Total length 420^. Maceration 798 slide 12B, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Red filter, same scale as figure 6, (xlOO). 5. Proximo-distal compression. Maximum dimension 570 /x. Maceration 798 slide 3, lowest coal in diamond drill core, Caseyville Group, Wa- bash County, Illinois. Reflected light, same scale as figure 1, (x50). 6. Proximo-distal compression. Characteristic development of distal ornamentation and flange. Maximum diameter 555 /x. Maceration 798 slide 11, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Red filter, scale indicated below figure, (xlOO). 7. Proximo-distal compression, apparently abraded. Maximum dimen- sion 470 ix. Maceration 796 slide 7, coal in Caseyville Group, Wabash County, Illinois. Red filter, same scale as figure 6, (xlOO). 8. Detail of spines. Maceration 798 slide 2RMK, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Red filter, same scale as figure 3, (xl50). 9. Extreme development of distal ornamentation. Spines up to 57 /x in length. Maceration 798 slide 1RMK, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Green filter, same scale as figure 3, (xl50). 10. Same spore. More or less solid flange, folded over in part, up to 53 /x in width. Green filter, same scale as figure 3, (xl50). Triletes globosus Arnold var. (C) p. 45 11. Characteristic proximo-distal compression. Maximum diameter 685^. Maceration 631 slide 1, Willis (?) Coal, Gallatin County, Illinois. Re- flected light, same scale as figure 1, (x50). 12. Detail of ornamentation. Tubercles up to 23^ in diameter. Macera- tion 625A1} slide 14, Willis Coal, Gallatin County, Illinois. Red filter, same scale as figure 3, (xl50). [in] PLATE 5 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes globosus Arnold p. 42 Figure 1. Proximo-distal compression. Radiating ridges only vaguely developed on contact areas. Diameter 545 /a. Maceration 618 slide 2, Reynoldsburg Coal, Johnson County, Illinois. Reflected light, scale indicated below figure, (X50). 2. Detail of rather stout spines. Maceration 909 slide 9, Battery Rock Coal, Pope County, Illinois. Red filter, same scale as figures 3, 5, (X150). 3. Detail of spines. Maceration 618 slide 6, Reynoldsburg Coal, Johnson County, Illinois. Red filter, scale indicated below figure, (xl50). 4. Fragment showing lips, torn apical prominence, and ornamentation of contact area and distal surface. Maceration 909 slide 5, Battery Rock Coal, Pope County, Illinois. Red filter, scale indicated below figure, (xlOO). 5. Deeply cleft spines up to 41 ^ in length. Maceration 906 slide 5, "Makanda" Coal, Jackson County, Illinois. Green filter, scale indicated above figure, (X150). 6. Detail of ornamentation. Maceration 929 slide 6, Rock Island (No. 1) Coal, McDonough County, Illinois. Green filter, same scale as figures 3, 5, (X150). Triletes cf. T. hirsutus (Loose) Schopf, Wilson, and Ben tall p. 45 7. Detail of characteristic ornamentation. Maceration 929 slide 6, Rock Island (No. 1) Coal, McDonough County, Illinois. Green filter, same scale as figures 3, 5, (xl50). Triletes splendidus (Zerndt) Schopf, Wilson, and Bentall p. 27 8. Broken lateral compression showing pyramidal apical prominence and stout distal spines. Total dimension, including spines, 1370 y^c. Macera- tion 200 slide 1 XXV, in Degonia Formation, Pope County, Illinois. Reflected light, same scale as figures 9a, 9b, (x30). Triletes praetextus Zerndt p. 46 9a. Oblique compression showing prominent apical prominence and ridges parallel to the rays. Equatorial dimension 1160yu. Maceration 587 slide 1, Battery Rock Coal, Hardin County, Illinois. Reflected light, scale indicated below figure, (x30). 9b. Same spore. View of other side showing the restriction of ornamenta- tion to a zone around the equator. Reflected light, scale indicated above figure, (x30). 10. Detail of the equatorial ornamentation showing the characteristic branching of the spines. Maceration 587 slide 3, Battery Rock Coal, Hardin County, Illinois. Red filter, same scale as figures 3, 5, (xl50). 112] Illinois State Geological Survey Bulletin 8(>, Plate 5 Winslow — Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 8(5, Plate 6 2000/i, Winslow — Mississippian-Pennsylvanian Spores PLATE 6 All specimens photographed with reflected light, unless otherwise indicated. Color of filter, when used, also indicated. Triletes indianensis Chaloner p. 26 Figure 1. Inner surface of one of three segments of apical prominence. Lip at apex up to 226 /j, in height. Maceration 943 slide 12, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Transmitted light. Red filter, same scale as figure 3, (xl50). 2. Proximo-distal compression showing pyramidal apical prominence. Diameter 1195^. Maceration 943 slide 1, coal in the Bethel (Moore- town) Formation, Hardin County, Kentucky. Same scale as figure 4, (X30). 3. Maximum development of spines observed. Spines up to 20 fx in length. Maceration 943 slide 14, coal in the Bethel (Mooretown) Formation, Hardin County, Kentucky. Transmitted light, red filter, scale indi- cated below figure, (xl50). Triletes echinoides Chaloner p. 47 4. Fragment of spore coat showing detail of spines. Length of straight spine 1595 /x. Maceration 888 slide 3, carbonaceous layer near base (?) of Glen Dean Formation, Wise County, Virginia. Transmitted light, scale indicated below figure, (x30). 5a. Lateral compression of a poorly preserved example. Spines present on contact areas, but longer and more closely spaced on distal sur- face. Total length including ornamentation 3560 /*. Maceration 888 slide 1, carbonaceous layer near base (?) of Glen Dean Formation, Wise County, Virginia. Scale indicated below figure, (xl5). 5b. Same spore. View of other side showing height of lips and contact area spines. Same scale as figure 5a, (xl5). Triletes cf. T. eregliensis Dijkstra p. 48 6. Two spores still in tetrad association along one contact face. Equa- torial dimension, measured below arcuate ridge, of larger spore 1130 y.. Maceration 604A slide 6, Tarter Coal, Fulton County, Illinois. Same scale as figure 8, (x20). Triletes glabratus Zerndt (sensu Dijkstra) p. 28 7. Immature spore with subtriangular outline. Diameter 665 /x. Macera- tion 463 slide 2, Suraraum (No. 4) Coal, Jersey County, Illinois. Same scale as figure 4, (x30). 8. Mature spore. Suture open. Diameter 2100 /x. Maceration 583 slide 1, Harrisburg (No. 5) Coal, Wabash County, Illinois. Scale indicated below figure, (x20). 9. Large specimen with slightly parted low lips. Diameter 2200 /x. Macera- tion 878 slide 1, Grape Greek (No. 6) Coal, Edgar County, Illinois. Same scale as figure 8, (x20). 10. Proximo-distal compression. Suture open. Diameter 2345 fx. Spore coat 26-31 ix in thickness. Maceration 600 slide 4, "LaSalle" Coal, Bureau County, Illinois. Transmitted light. Red filter, same scale as figure 8, (X20). [115 PLATE 7 All specimens photographed with reflected light. Triletes mamillarius Bartlett (sensu Dijkstra) p. 28 Figure 1. Immature spore with subtriangular outline. Diameter 820 p. Macera- tion 625 A2 slide 1, Willis Coal, Gallatin County, Illinois. Same scale as figure 15a, (x20). 2. Slightly larger spore with more rounded outline. Maceration 625AX slide 2, Willis Coal, Gallatin County, Illinois. Same scale as figure 15a, (X20). 3. Still larger example with open trilete suture. Maceration 625Aa slide 2, Willis Coal, Gallatin County, Illinois. Same scale as figure 15a, (x20). 4. One of largest examples. Maceration 625Aj slide 2, Willis Coal, Galla- tin County, Illinois. Same scale as figure 15a, (x20). 5. Largest dry specimen observed in Willis Coal. Diameter 1540^. Mac- eration 625B slide 4, Willis Coal, Gallatin County, Illinois. Same scale as figure 15a, (x20). 6a. Characteristic example showing small contact area spines and well de- veloped distal spines. Suture open. Maceration 795 slide 1, coal in Caseyville Group, Wabash County, Illinois. Same scale as figure 15a, (x20). 6b. Same spore. Distal view. Same scale as figure 15a, (x20). Triletes auritus Zerndt (sensu Potonie and Kremp) p. 30 7-9. Proximo-distal compressions illustrating the range in size and "ear" configuration of spores of the species from one coal. Total diameter of spores 855//,, 955//,, and 1205^, respectively. Maceration 733c slide 1, Battery Rock Coal, Crittenden County, Kentucky. Same scale as figure 16, (x25). 10. Proximo-distal compression. Maximum dimension 830 /x. Maceration 914 slide 1, Tarter Coal, Mercer County, Illinois. Same scale as figure 16, (x25). 11. Lateral compression showing highly developed "ears" and slight apical prominence. Maximum dimension 1110/*. Maceration 604A slide 2, Tarter Coal, Fulton County, Illinois. Same scale as figure 16, (x25). Triletes augustae (Loose) Schopf, Wilson, and Bentall (sensu Potonie and Kremp p. 31 12. Proximo-distally compressed spore with the highest lips observed for spores of this species. Maximum dimension 1095 /t. Maceration 588 slide 2, Babylon Coal, Fulton County, Illinois. Same scale as figure 16, (x25). 13. Small example with low, straight rays. Diameter 925 /*. Maceration 602 slide 5, Pope Creek Coal. Fulton County, Illinois. Same scale as figure 16, (x25). Triletes appendiculatus ? Maslankiewiczowa p. 31 14. Spore with one "ear" and portion of one interradial area broken away. Width of largest ear 410 /*. Maximum dimension 1120/x. Maceration 950A slide 1, coal in Tradewater Group, Grundy County, Illinois. Same scale as figure 16, (x25). Triletes (Auriculati) spp p. 32 15a. Spore with low ridge-like lips. Total diameter 1900 /t. Maceration 583 slide 1, Harrisburg (No. 5) Coal, Wabash County, Illinois. Scale indi- cated below figure, (x20). 15b. Same spore. Distal view. Same scale as figure 15a, (x20). 16. Lateral compression with slightly undulatory arcuate ridges and pitted contact areas. Maximum dimension 1795 /*. Maceration 583 slide 1, Harrisburg (No. 5) Coal, Wabash County, Illinois. Scale indicated below figure, (x25). 17. Proximo-distal compression. Diameter 1130 /i. Maceration 703 slide 1, "Woodbury" Coal, Cumberland County, Illinois. Same scale as figure 16, (X25). 18. Spore with undulatory arcuate ridges, pitted contact areas, and straight rays. Diameter 1300 /*. Maceration 811 slide 1, "Divide" Coal, Jeffer- son County, Illinois. Same scale as figure 16, (x25). [116] Illinois State Geological Survey Bulletin 8(>, Plate 7 500 ft Winslow — Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 86, Plate 8 Winslow— Mississippian-Pennsylvanian Spores PLATE 8 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes rotatus Bartlett p. 32 Figure 1 . Detail of flange showing short, thornlike projections on rim of flange. Maceration 910 slide 2, coal in Cascyville Group, Pope County, Illinois. Red filter, scale indicated below figure, (XlOO). 2. Broken proximo-distal compression. Maximum dimension 1465 fi. Maceration 910 slide 2, coal in Caseyville Group, Pope County, Illi- nois. Red filter, scale indicated below figure, (x40). Triletes ramosus Arnold p. 33 3a. Proximal view. Contact areas ornamented with scattered tubercles. Total diameter 1590 u. Maceration 625A2 slide 2, Willis Coal, Gallatin County, Illinois. Reflected light, scale indicated below figure, (x20). 3b. Same spore. Distal view showing ornamentation over entire distal sur- face. Reflected light, scale indicated above figure, (x20). 4a. Proximo-distal compression. Flange elements closely spaced. Maximum dimension 1600^. Maceration 625Aj slide 12, Willis Coal, Gallatin County, Illinois. Red filter, same scale as figure 2, (x40). 4b. Same spore. Detail of marginal projections of flange. Red filter, same scale as figure 1, (X100). 5. Oblique compression. Flange elements not as closely spaced as on spore shown in figure 4. Maximum dimension 1600^. Maceration 625Aj slide 12, Willis Coal, Gallatin County, Illinois. Red filter, same scale as figure 2, (x40). G. Detail of flange with longer marginal projections. Projections up to 103 ,u in length. Maceration 626 slide 4, Rock Island (No. 1) Coal, Henry County, Illinois. Red filter, same scale as figure 1, (X100). Triletes superbus Bartlett p. 31 7. Rare example of laterally compressed specimen. Thin processes present on contact areas, apparently absent on distal surface. Maceration 625Aj slide 4, Willis Coal, Gallatin County, Illinois. Reflected light, same scale as figures 3a, 3b, (x20). 8. Distal view of proximo-distal compression showing completely orna- mented distal surface. Most of flange broken away. Spore body di- ameter 1830 fi. Maceration 906 slide 1, "Makanda" Coal, Jackson County, Illinois. Reflected light, same scale as figures 3a, 3b, (x20). [119 PLATE 9 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes superbus Bartlett p. 31 Figure 1. Fragment of flange 1175^ in width. Maceration 906 slide 3, "Ma- kanda" Coal, Jackson County, Illinois. Same scale as figure 2, (x40). 2. Typically fenestrate flange showing delicate nature of some of the flange elements. Width 1180>. Maceration 906KOH slide 3, "Ma- kanda" Coal, Jackson County, Illinois. Red filter, scale indicated below figure, (X40). Triletes brasserti Stach and Zerndt p. 35 3. Tetrad. Maceration 604A slide 4, Tarter Coal, Fulton County, Illinois. Reflected light, scale indicated below figure, (xlO). 4a. Characteristic proximo-distal compression. Total diameter 1710 [x. Maceration 604A slide 3, Tarter Coal, Fulton County, Illinois. Re- flected light, same scale as figure 5, (x20). 4b. Same spore. Distal view showing granulose to spongy appearance of distal surface of flange. Reflected light, same scale as figure 5, (x20). 5. Lateral compression. Part of contact surface, flange, and distal coat lorn away showing thickness of flange at its juncture with trilete rays. Maceration 604A slide 3, Tarter Coal, Fulton County, Illinois. Re- flected light, scale indicated below figure, (x20). 6. Proximo-distal compression with pleated flange. Total diameter 1795 p. Maceration 625B slide 1, Willis Coal, Gallatin County, Illinois. Re- flected light, same scale as figure 5, (x20). 7. Small example, immature (?). Maximum dimension 990^. Maceration 625B slide 2, Willis Coal, Gallatin County, Illinois. Reflected light, same scale as figure 5, (x20). 8a. Oblique compression of small example with part of flange attached. Inner membrane distinctly ornamented. Total diameter 925 /x. Macera- tion 625 Ai slide 13, Willis Coal, Gallatin County, Illinois. Red filter, scale indicated below figure, (x50). 8b. Same spore. Detail of inner membrane. Red filter, scale indicated be- low figure, (xlOO). 9. Corner of flange torn from spore body. Distal margin of contact with spore body shows as dark medial band. Width at corner 490 jx. Mac- eration 625 B slide 7, Willis Coal, Gallatin County, Illinois. Red filter, same scale as figure 8b, (xlOO). 10. Detail of flange showing imbricating platelike nature of the distal surface of the solid, nonfenestrate flange. Maceration 625B slide 6, Willis Coal, Gallatin County, Illinois. Red filter, same scale as figure 8b, (xlOO). [ 120 Illinois State Geological Survey Bulletin 86, Plate 9 Winslow — Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 86, Plate 10 400yU. 'fir *T^ &i % ^S$kid* .10 500/* 800 /i Winslow— Mississippian-Pennsylvanian Spores PLATE 10 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes triangulatus Zerndt (sensu Dijkstra) p. 38 Figure la. Proximo-distal compression showing coarse distal reticulation. Total diameter 740 p. Maceration 798 slide 12 A, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Red filter, same scale as figures 3, 4a, (X50). lb. Same spore. Detail of ornamentation. Red filter, same scale as figure 2b, (xl 00). 2a. Proximo-distal compression showing distal reticulation of a slightly different aspect. Total diameter 625 /*. Maceration 798 slide 15, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illi- nois. Red filter, same scale as figures 3, 4a, (x50). 2b. Same spore. Detail of ornamentation. Red filter, scale indicated below figure, (X100). 3. Distal view showing fine reticulation. Maceration 588 slide 2, Babylon Coal, Fulton County, Illinois. Reflected light, scale indicated below figure, (X50). 4a. Proximal view. Maximum dimension 685 /n. Maceration 604A slide 6, Tarter Coal, Fulton County, Illinois. Reflected light, scale indicated above figure, (x50). 4b. Same spore. Distal view. Reflected light, same scale as figures 3, 4a, (X50). 5. Distal ornamentation in focus. Maximum dimension 595 fi. Macera- tion 550 slide 2, Murphysboro Coal, Jackson County, Illinois. Red filter, same scale as figures 3, 4a, (x50). 6. Proximo-distal compression showing reticulations on flange. Macera- tion 603B slide 4, Colchester (No. 2) Coal, Fulton County, Illinois. Green filter, same scale as figures 3, 4a, (X50). 7. Lateral compression showing lips, coarse distal reticulation, and ir- regularly developed proximal reticulation. Maximum dimension 810^. Maceration 603C slide 2, Colchester (No. 2) Coal, Fulton County, Illi- nois. Red filter, same scale as figures 3, 4a, (x50). 8. Lateral compression showing fine proximal and coarse distal reticula- tions. Maceration 799B slide 1, Murphysboro Coal, Jackson County, Illinois. Red filter, same scale as figures 3, 4a, (x50). 9. Proximo-distal compression of denuded example. Inner membrane characteristically ornamented. Diameter 540^. Maceration 603B slide 4, Colchester (No. 2) Coal, Fulton County, Illinois. Red filter, scale indicated above figure, (x75). 10. Proximal ornamentation in focus. Total diameter 680 jx. Maceration 599B slide 7, Rock Island (No. 1) Coal, Fulton County, Illinois. Red filter, same scale as figures 3, 4a, (x50). Triletes ? saturnipunctatus n. sp p. 48 11. Slightly oblique compression. Holotype. Diameter 433^. Maceration 916 slide 5, Pope Creek Coal, Mercer County, Illinois. Red filter, same scale as figure 2b, (xl00). 123] PLATE 11 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Triletes ? corycilis n. sp p. 49 Figure 1. Lateral compression. Holotype. Suture slightly open. Length 1055 fi. Maceration 798 slide 10, lowest coal in diamond drill core, Casey ville Group, Wabash County, Illinois. Red filter, same scale as figure 6, (X50). 2. Lateral compression. Narrow frill shows at edges of one contact area. Length 1110^. Maceration 798 slide 10, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Same scale as figure 6, (X50). 3a. Broken lateral compression. Two contact areas show central scar. Maximum dimension 1270 /x. Maceration 798 slide 10, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Same scale as figure 6, (x50). 3b, 3c. Same spore. Details of contact areas. Scale indicated below figure 3c, (x75). Cystosporites verrucosus Dijkstra p. 53 4. Lateral compression of fertile spore with long distal appendage. Total length 3420^. Maceration 825 slide 1, Colchester (No. 2) Coal, Schuyler County, Illinois. Reflected light, scale indicated to right of figure, (xl5). 5. Lateral compression of fertile spore. Apical area characteristically pleated. Small portion of distal appendage still attached. Maximum dimension 2535^. Maceration 881 slide 1, Indiana Coal IV, Edgar County, Illinois. Reflected light, scale indicated to left of figure, (X15). 6. Lateral compression of abortive spore. Part of spatulate apical promi- nence torn away. Total length 700 fi. Maceration 916 slide 5, Pope Creek Coal, Mercer County, Illinois. Red filter, scale indicated below figure, (X50). 7. Detail of spinose spore coat from fertile spore. Fibrous meshlike char- acter of spore coat well developed. Maceration 916 slide 2, Pope Creek Coal, Mercer County, Illinois. Scale indicated below figure, (xl50). 8. Detail of spinose spore coat from fertile spore. Maceration 916 slide 2, Pope Creek Coal, Mercer County, Illinois. Scale indicated above figure, (X150). Cystosporites giganteus (Zerndt) Schopf p. 52 9. Oblique compression showing proximal view of relatively small con- tact area. Maximum dimension 2600 fi. Maceration 825 slide 2, Col- chester (No. 2) Coal, Schuyler County, Illinois. Same scale as figures 4, 5, (xl5). 10. Lateral compression of fertile spore. Small abortive spore also present. Total length 6210^. Maceration 943 slide 3, coal in the Bethel (Moore- town) Formation, Hardin County, Kentucky. Scale indicated below figure, (X10). [124 Illinois State Geological Surve :v Bulletin 86, Plate n Winslow— Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 86, Plate 12 Winslow — Mississippian-Pennsylvanian Spores PLATE 12 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Cystosporites giganteus (Zerndt) Schopf p. 52 FlCURE 1. Abortive spore. Maximum dimension 720 ll- Maceration 908 slide 2, Battery Rock Coal, Pope County, Illinois. Reflected light, scale indi- cated below figure, (x40). 2. Apical portion of fertile spore. Abortive spore also present. Maceration 824 slide 2, Colchester (No. 2) Coal, Schuyler County, Illinois. Re- flected light, same scale as figure 1, (x40). 3. Detail of spore coat from middle region of fertile spore. Maximum de- velopment of fibrous meshlike coat observed. Maceration 824 slide 3, Colchester (No. 2) Coal, Schuyler County, Illinois. Same scale as fig- ures 9b, 9c, (X150). 4. Lateral compression of small fertile spore with distal appendage. Maceration 523A slide 1, Babylon Coal, Fulton County, Illinois. Re- flected light, scale indicated below figure, (x20). Cystosporites varius (Wicher) Dijkstra p. 51 5. Lateral compression of larger abortive (?) spore. Total length 1180/4. Maceration 604A slide 1, Tarter Coal, Fulton County, Illinois. Re- flected light, scale indicated below figure, (x30). 6. Proximo-distal compression of small abortive spore with prominent three-lobed apical cushion. Maximum dimension 530 p. Maceration 824 slide 2, Colchester (No. 2) Coal, Schuyler County, Illinois. Reflected light, scale indicated below figure, (x50). 7. Detail of apical region of large abortive (?) spore. Apical cushion torn away revealing open trilete suture. Maceration 625B slide 14, Willis Coal, Gallatin County, Illinois. Scale indicated below figure, (xlOO). 8. Detail of spore coat from middle region of fertile spore. Fibrous struc- ture not as well developed as is usual for these spores. Maceration 824 slide 8, Colchester (No. 2) Coal, Schuyler County, Illinois. Same scale as figures 9b, 9c, (xl50). Cystosporites breretonensis Schopf p. 50 9a. Fertile and abortive spores, both possessing apical cushions and a re- ticulate-appearing pattern on the spore coat. Length of fertile spore 3390 fi. Maceration 611 slide 1, Colchester (No. 2) Coal, Grundy Coun- ty, Illinois. Scale indicated below figure, (xl5). 9b. Same specimen. Detail of spore coat of fertile spore in apical region showing the reticulate-appearing pattern. Scale indicated below figure, (X150). 9c. Same specimen. Detail of spore coat of abortive spore showing some- what coarser reticulate pattern. Scale indicated above figure, (xl50). 10. Abortive spore showing granulose outline of apical cushion and reticu- late-appearing coat Total length 1030 it. Maceration 825 slide 3, Col- chester (No. 2) Coal, Schuyler County, Illinois. Red filter, same scale as figure 5, (x30). 11. Distal view of abortive spore. Closely spaced, low prominences cause the reticulate appearance of the coat. Maximum dimension 665 fx. Maceration 583 slide 1, Harrisburg (No. 5) Coal, Wabash County, Illi- nois. Reflected light, same scale as figure 6, (x50). [127] PLATE 13 All specimens photographed with transmitted light. Color of filter, when used, indicated. Spencerisporites cf. S. radiatus (Ibrahim) n. comb p. 56 Figure 1. Spore with lips and contact areas split apart and partly folded. Total diameter 375/*. Maceration 798 slide 13, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Green filter, same scale as figures 2, 5a, (xlOO). 2. Spore with torn bladder showing upper and lower bladder membranes. Total diameter 365 /x. Maceration 798 slide 1RMK, lowest coal in dia- mond drill core, Caseyville Group, Wabash County, Illinois. Green filter, scale indicated below figure, (xlOO). 3. Spore showing gouge-like appearance of radial striations and a narrow marginal flange. Total diameter 385 /x. Maceration 798 slide 13, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Green filter, same scale as figures 2, 5a, (xlOO). 4. Spore showing high lips expressed as folds on upper surface of blad- der. Total diameter 345 /x. Maceration 798 slide 13, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Green filter, same scale as figures 2, 5a, (xlOO). 5a. Spore with slightly wider marginal flange. Total diameter 314 p. Maceration 618 slide 3, Reynoldsburg Coal, Johnson County, Illinois. Scale indicated above figure, (xlOO). 5b. Same spore. Detail of spore body and radial striations. Green filter, same scale as figure 6, (x200). 6. Detail of marginal flange. Maceration 618 slide 3, Reynoldsburg Coal, Johnson County, Illinois. Scale indicated below figure, (X200). Spencerisporites cf. S. gracilis (Zerndt) n. comb p. 58 7. Poorly preserved spore with wide marginal flange and reticulate- appearing central area. Maximum dimension 443 /x. Maceration 519B slide 3, DeKoven Coal, Williamson County, Illinois. Green filter, same scale as figures 2, 5a, (xlOO). 8. Small spore showing wide marginal flange and distinct reticulate- appearing folds in central area. Total diameter 315/*. Maceration 879 slide 4, Harrisburg (No. 5) Coal, Edgar County, Illinois. Green filter, same scale as figures 2, 5a, (xlOO). 9. Spore with wide marginal flange which appears lobe-like in outline at two of the corners. Total diameter 388 /x. Maceration 133, "Bogota" Coal, Fayette County, Illinois. Green filter, same scale as figures 2, 5a, (xlOO). Calamospora cf. C. sinuosa (Potonie and Kremp) ex Horst p. 60 10. Folded proximo-distal compression. Diameter 700 /x. Maceration 625AX slide 10, Willis Coal, Gallatin County, Illinois. Scale indicated below figure, (x75). Calamospora cf. C. laevigata (Ibrahim) Schopf, Wilson, and Bentall . . p. 60 11. Oblique compression with relatively short suture and vaguely defined contact areas. Diameter 314 fx. Maceration 600 slide 11, "LaSalle" Coal, Bureau County, Illinois. Scale indicated below figure, (xl50). Calamospora sp p. 61 12. Oblique compression of small spore with relatively thick coat. Thick- ening of spore coat in contact area showing at upper margin. Diameter 185 fx. Maceration 600 slide 11, "LaSalle" Coal, Bureau County, Illinois. Same scale as figure 11, (xl50). [128 Illinois State Geological Survey Bulletin 8(5, Plate 13 -*~&^ 200 fi 500/i J L 300 /J. 4J£ f Winslow— Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 86, Plate 14 3000/X Winslow — Mississippian-Pennsylvanian Spores PLATE 14 All specimens photographed with transmitted light, unless otherwise indi- cated. Color of filter, when used, also indicated. Monoletes spp p. 62 Figure 1. Small proximo-distal compression showing distal folds and medially deflected suture. Inner coat detached from outer coat and folded at each end. Total length 200^. Maceration 795 slide 11, coal in Casey - ville Group, Wabash County, Illinois. Green filter, same scale as fig- ures 8, 11, (X150). 2. Proximo-distal compression showing distal folds and medially deflected suture. Length 353 /j.. Maceration 906KOH slide 6, "Makanda" Coal, Jackson County, Illinois. Same scale as figures 8, 11, (X150). 3. Proximo-distal compression. Distal folds and medially deflected suture evident. Inner coat detached from outer coat and folded. Total length 489 fi. Maceration 915 slide 5, Murphysboro (?) Coal, Williamson County, Illinois. Red filter, same scale as figures 4, 7, (xlOO). 4. Proximo-distal compression showing distal folds and medially deflected suture. Inner coat detached from outer coat and folded. Length 401 u. Maceration 599B slide 9, Rock Island (No. 1) Coal, Fulton County, Illinois. Red filter, scale indicated below figure, (xlOO). 5. Proximo-distal compression showing vague outline of distal folds. Suture medially deflected with extremely short possible vestigial third ray. Length 298 p.. Maceration 899 slide 2, Colchester (No. 2) Coal, Fulton County, Illinois. Same scale as figures 8, 11, (X150). 6. Well preserved proximo-distal compression showing distal folds and medially deflected suture. Length 515 fx. Maceration 35 slide 3, un- named coal above DeKoven Coal, Saline County, Illinois. Same scale as figures 4, 7, (xlOO). 7. Proximo-distal compression. Central body small with thick coat, 288 /j. in length. Short third ray 26 fi in length. Maceration 35 slide 2, un- named coal above DeKoven Coal, Saline County, Illinois. Red filter, scale indicated above figure, (xlOO). 8. Proximo-distal compression. Suture masked by thin folds. Length 278 fi. Maceration 600 slide 11, "LaSalle" Coal, Bureau County, Illi- nois. Green filter, scale indicated below figure, (xl50). 9. Proximo-distal compression of spore from spore mass showing distal folds and medially deflected suture. Very short third ray present. Length 355 /z. Maceration 811 slide 9, "Divide" Coal, Jefferson County, Illinois. Same scale as figures 8, 11, (xl50). 10. Spore masses. Maceration 811 slide 2, "Divide" Coal, Jefferson County, Illinois. Reflected light, scale indicated below figure, (xl5). Parasporites spp p. 63 11. Slightly oblique lateral compression showing position of bladders. Length of spore body 272 y,. Maceration 490D slide 4, Friendsville Coal, Wabash County, Illinois. Scale indicated above figure, (xl50). 12. Proximo-distal compression showing medially deflected suture with very short third ray. Total length 309 p.. Maceration 579C slide 5, Col- chester (No. 2) Coal, Bureau County, Illinois. Red filter, same scale as figures 8, 11, (xl50). 131 1 PLATE 15 All specimens photographed with transmitted light. Color of filter, when used, indicated. Punctatisporites cf. P. obesus (Loose) Potoni£ and Kremp p. 64 Figure 1. Poorly preserved example. Suture open. Diameter 145 /x- Maceration 625Bf slide 4, Willis Coal, Gallatin County, Illinois. Safranin stained. Same scale as figure 3, (x300). 2. Smaller example with more triangular outline. Diameter 112 /x. Mac- eration 625Bf slide 5, Willis Coal, Gallatin County, Illinois. Safranin stained. Same scale as figure 3, (x300). Reticulatisporites cf. R. irregularis Kosanke p. 64 3. Proximo-distal compression. Two rays of suture barely visible. Diam- eter 158 ix. Maceration 144, "Sub-Babylon" Coal, Fulton County, Illi- nois. Green filter, scale indicated below figure, (X300). Renisporites confossus n. sp p. 65 4. Lateral compression showing thickening of spore coat around suture. One lateral puncta group in focus. Length 169 /x. Maceration 625A2 slide 10, Willis Coal, Gallatin County, Illinois. Same scale as figure 3, (X300). 5a. Proximo-distal compression. Holotype. Length 170 /x. Maceration 625Bf slide 2, Willis Coal, Gallatin County, Illinois. Safranin stained. Same scale as figure 3, (x300). 5b. Same spore. Detail of lateral puncta group. Scale indicated below fig- ure, (X600). Sporangial masses of Densosporites p. 67 6. Total length 4200 p. Maceration 604A slide 8, Tarter Coal, Fulton County, Illinois. Scale indicated below figure, (xlO). 7. Cuticle from sporangial mass of Densosporites. Maceration 604A slide 11, Tarter Coal, Fulton County, Illinois. Scale indicated below figure, (X150). Seed membranes p. 67 8. Inner membrane enclosed in a thin membrane with coarse reticulate- appearing surface. Length 3435 p. Maceration 798 slide 7, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Same scale as figure 9, (xl5). 9. Large membrane with thick coat. Length about 5345 p. Maceration 760 slide 1, coal in Tar Springs Formation, Johnson County, Illinois. Red filter, scale indicated below figure, (xl5). 10. Seed membrane with apical cap. Length 2980 p. Maceration 760 slide 4, coal in Tar Springs Formation, Johnson County, Illinois. Same scale as figure 9, (xl5). [132] Illinois State Geological Survey Bulletin 86, Plate 15 ■400 m Winslow— Mississippian-Pennsylvanian Spores Illinois State Geological Survey Bulletin 8(>, Plate 16 Winslow — Mississippian-Pennsylvanian Spores PLATE 16 All specimens photographed with transmitted light. Color of filter, when used, indicated. Seed membranes p. 67 Figure 1. Seed membrane? Length 3455 /j,. Maceration 625B slide 15, Willis Coal, Gallatin County, Illinois. Scale indicated below figure, (xl5). 2. Inner thick membrane enclosed in thin membrane, partially torn away from apical region. Length 2540^. Maceration 811 slide 4, "Di- vide" Coal, Jefferson County, Illinois. Scale indicated below figure, (X15). Miscellaneous plant microfossils from Illinois coals p. 68 3. Resin bleb with spinose "stalk." Total length 835 [i. Maceration 599B slide 4, Rock Island (No. 1) Coal, Fulton County, Illinois. Same scale as figure 4, (X50). 4. Cuticle showing arrangement of stomata in parallel rows. Maceration 608 slide 2, Murphysboro Coal, Jackson County, Illinois. Red filter, scale indicated below figure, (x50). 5. Pitted cuticle. Maceration 631 slide 3, Willis (?) Coal, Gallatin County, Illinois. Same scale as figure 9, (x40). 6. Cuticle. Openings up to 46 ^ in diameter. Maceration 918 slide 1, Pope Creek Coal, Mercer County, Illinois. Red filter, same scale as figure 9, (x40). 7. Characteristic cuticle of the Reynoldsburg Coal. Cuticle has dome cells with cuticular crests. Maceration 618 slide 5, Reynoldsburg Coal, Johnson County, Illinois. Scale indicated below figure, (x25). 8. Wood fragment with medullary rays. Pit mouths up to 10 ^ in length. Maceration 525B slide 6, Wiley Coal, Fulton County, Illinois. Same scale as figure 9. (x40). 9. Fusinized wood fragment. Maceration 906 slide 6, "Makanda" Coal, Jackson County, Illinois. Scale indicated to right of figure, (x40). Membranes of animal (?) origin p. 68 10. More or less round openings up to 66 ^ in diameter. Membrane as a whole ornamented with closely spaced depressions up to 10^ in di- ameter. Maceration 798 slide 7, lowest coal in diamond drill core, Caseyville Group, Wabash County, Illinois. Same scale as figure 9, (x40). 11. Membrane similar in pattern to that shown above, but thinner and with smaller openings and depressions. Maceration 914 slide 7, Tarter Coal, Mercer County, Illinois. Same scale as figure 9, (x40). [135] Illinois State Geological Survey Bulletin 86 135 p., 16 pis., 9 figs., 3 tables, 1959