UC-NRLF C E fl?l SD1 University of Texas Bulletin No. 1X56: October S. The Weno and Pawpaw Formations of the Texas Gomanchean IIV W. S. AdVins \ On A New Ammonite Fauna of the Lower Turonian of Mexico BY Emil Hose Bureau of Economic Geology and Technoli gy Division of Economic Geology . A. Udden, Director of the Bureau and Head of f ?ie Division PUBLISHED BY THE UNIVERSITY OF TEXAS AUSTIN EARTH SCIENCES LIBRARY 51520 9«04818-2m University of Texas Bulletin No. 1856: October 5, 1918 The Weno and Pawpaw Formations of the Texas Gomanchean BY , . ' . - . • •: ; '.' , W. S. Adkins On A New Ammonite Fauna of the Lower Turonian of Mexico BY Emil Hose Bureau of Economic Geology and Technology Division of Economic Geology J. A. Udden. Director of the Bureau and Head of the Division PUBLISHED BY THE UNIVERSITY SIX TIMES A MONTH, AND ENTERED AS SECOND-CLASS MATTER AT THE POSTOFFICE AT AUSTIN. TEXAS, UNDER THE ACT OF AUGUST 24, 1912 The benefits of education and of useful knowledge, generally diffused through a community, are essential to the preservation of a free govern- ment. Sam Houston Cultivated mind is the guardian genius of democracy It is the only dictator that freemen acknowl- edge and the only security that free- men desire. Mirabeau B. Lamar EARTH SCIENCES LIBRARY The Weno and Pawpaw Formations of the Texas Gomanchean BY W. S. Adkins CONTENTS INTRODUCTION 9 STRATIGRAPHY 13 Rocks underlying the Weno and Pawpaw Formations Pre-Comanchean *" Comanchean *4 Thickness changes Lithological changes Weno and Pawpaw Formations Thickness changes 25 North-South changes 25 East-West changes 26 Lithological changes Pawpaw Formation > Weno Formation 35 Stratigraphic Correlation 40 North Central Texas and Southern Oklahoma 40 South Central Texas 40 West Texas and Mexico 41 Europe and North Africa 4 a PALEONTOLOGY 44 The Weno Fauna 45 The Pawpaw Fauna 4? Comparison of Pyrite Faunae 53 Texas 53 Kiamitia Clay Fauna 54 Duck Creek Marl Fauna 64 Denton Clay Fauna '. 55 Grayson Fauna 5(5 Del Rio Clay Fauna 58 Summary of Pyrite Faunae 60 Europe and Africa DESCRIPTIONS OF SPECIES 68 CEPHALOPODA 68 Nautilus texanus Shumard 6S Nautilus sp Hamites tenawa Adkins and Winton 69 Hamites sp. aff. armatus Sowerby Ancycloceras bendirei n. sp '" Hamulina wortkensis n. sp Baculites comanchensis n. sp ?4 Turrilitcs bosquensis n. Sp Turrilites worthensis Adkins and Winton 78 Turrilites sp Scaphites hilli Adkins and Winton 79 6 University of Texas Bulletin Engonoceras serpentinum (Cragin) 8-1 Engonoceras sp 85 Flickia boesei n. sp 85 Flickia (?) bosquensis n. sp 87 Schloenbachia wenoensis n. sp 89 Schloenbachia wintoni n. sp 90 Mortoniceras worthense n. sp 91 Acanthoceras worthense n. sp 93 ASTEROIDEA , 95 Pentagonaster texensis Adkins and Winton 95 Metopaster hortensae Adkins and Winton 97 Comptonia wintoni n. sp. 97 Pentaceros americanus n. sp 99 ECHINOIDEA 101 Leiocidaris sp 101 Goniopygus sp 102 Pedinopsis symmetries (Cragin) 102 Peltastes sp 102 Salenia sp 103 Cyphosoma volanum Cragin 103 Holectypus limitis Bose 103 Holaster sp. aff. simplex Shumard 104 Epiaster wenoensis n. sp 105 Epiaster aguilerae Bose 109 Epiaster subobesus n. sp : 110 Enallaster wenoensis n. sp 112 Enallaster bravoensis Bose 114 Enallaster sp. aff. texanus (Roemer) Hi Hemiaster calvini Clark ; 114 Hemiaster riovistae n. sp 115 PELECYPODA *. H8 Nucula nokonis n. sp 118 Nucula wenoensis n. sp 120 Area washitaensis n. sp 121 Gervilliopsis invaginata (White) 122 Ostrea carinata ? Lamarck 122 Ostrea sp. aff. diluviana Linnaeus 122 Ostrea (Alectryonia) quadriplicata Shumard 123 Exogyra sp. aff. arietina Roemer 123 Pecten inconspicuus Cragin 123 Pecten georgetownensis Kniker 125 Venericardia wenoensis n. sp 125 Protocardia sp. aff. multistriata (Shumard) 126 Corbula wenoensis n. sp 127 Corbula basiniformis n. sp *. 130 Corbula littoralis n. sp ^33 Cyprimeria washitaensis n. sp 134 Remondia ? acuminata (Cragin) 13g Weno and Pawpaw Formations GASTROPODA 137 Amberleya graysonensis n. sp 137 Trochus laticonicus n. sp 138 Helicocryptua mexicnnus B6i»e 139 Nerita sp 139 Neritina sp 139 Anchura mudgeana White 139 Natica sp 140 Lunatia sp 140 Globiconcha sp 140 Turritella graysonensis n. sp 140 Turritella worthensis I), sp 142 Cinulia washitacnsis n. sp 143 PROTOZOA 145 Nodoiaria texana Conrad 145 BIBLIOGRAPHY 146 PLATES 1—11. . ..149-170 8 University of Texas Bulletin LIST OF ILLUSTRATIONS FIGURES Figure 1. Map of Texas and part of Oklahoma showing outcrops of the Weno and Pawpaw formations, and the lithological facies of the Pawpaw formation 11 Figure 2. Ancycloceras bendirei n. sp., suture of the type individual, camera lucida drawing, x 5 71 Figure 3. Hamulina worthense n. sp., sutures of type individual, camera lucida drawing, x 15 73 Figure 4. Baculites conuanchentis n. sp., sutures of type individual, camera lucida drawing, x 8 75 Figure 5. Turrilites bosquentis n. sp., sutures, type individual, camera lucida drawing, x 8 77 Figure 6. Scaphttes hilli Adkins and Winton, type individual, diagrammatic restoration showing orientation and sutures, camera lucida drawing, x 12 82 Figure 7. Scaphites hilli Adkins and Winton, young individual, showing the last five sutures, camera lucida drawing, x 10 83 Figure 8. Scaphite* hilli Adkins and Winton, external and internal suture, camera lucida drawing, x 10 84 Figure 9. Flickia boeiei n. sp., type individual, sutures, camera lucida draw- ing, x 8 v 86 Figure 10. Flickia bosquensis n. sp., diagrammatic projection of sutures of type individual, camera lucida drawing, x 5 88 Figure 11. Schloenbachia wintoni n. sp., type individual, last suture, camera lucida drawing, x 5. Keel region slightly distorted in type individual r 91 • Figure 12. Mortoniceras worthense n. sp., suture of individual, Plate 1, figure 6, camera lucida drawing, x 10 93 Figure 13. Acanthoceras worthense n. sp., suture, camera lucida drawing, x 8 94 PLATES Plates 1 — 11. Fossils of the Weno and Pawpaw formations . .149-170 THE WENO AND PAWPAW FORMATIONS OF THE TEXAS COMANCHEAN1 By W. S. ADKINS INTRODUCTION The Weno and Pawpaw formations are two thin formations lying near the top of the Comanchean series of strata, and are most typically developed in the region between the Red and the Brazos rivers. The importance of these formations, especially the Pawpaw, is much greater than their thick- ness would seem to indicate. The Pawpaw is a formation of small thick- ness, sharply limited lithologically both above and below, and contains a remarkable series of small pyritic fossils which are so sharply charac- terized and so distinctive in appearance, even in minute fragments such as are encountered in drilling, that this formation should be recognized in wells lying to the east of its outcrop and should furnish at least one certain and dependable stratigraphic level in the Comanchean. In the hope that the formation may have this value, its fauna has been described in some detail and the lateral variations in its lithological character indicated.2 The same statements hold to a lesser extent for the Weno formation. The stratigraphic position of these two formations in the Comanchean series and their equivalents in the Central Texas section are given in the fol- lowing table. The Weno and Pawpaw formations are visible over a small areal extent, their outcrops aggregating somewhat more than 100 square miles, mainly in a narrow strip in Johnson, Tarrant, Denton, Gooke and Grayson Coun- ties, Texas, and Love, Marshall, Bryan and Choctaw Counties, Oklahoma. In addition they have stratigraphic equivalents in Central and Western Texas and in Mexico, that will be discussed later. Their north-south dis- tribution in Texas is between Lat. 32°N. and 34°N. ; and their east-west distribution is practically unknown. In Oklahoma their east-west distri- bution is between Long. 95°15' and 97° ; and their north-south distribution is unknown. The total length of their outcrop north of the Brazos River 'Manuscript accepted June 15, 1920, published November, 1920. "It is hoped that operators and others having well samples suspected of being Upper Comanchean will submit them for examination to the Bureau of Economic Geology at Austin. 3I wish to express my indebtedness to Professor W. M. Winton, with whom the preliminary work on these and other Comanchean formations was done jointly. The results of these studies will appear in forthcoming papers by both authors. 10 University of Texas Bulletin CORRELATION TABLE OF THE COMANCHEAN FORMATIONS OF CENTRAL TEXAS' Series Division Formations North of the Brazos River Formations South of the Brazos River Stage UPPER .CRETA-. ofldya.: ' .'. ."' '. '-•' Uagleford Eagleford TURONIAN COMANCHEAN WASHITA Woodbine Grayson Mainstreet Pawpaw Weno Denton Fort Worth Duck Creek marl Duck Creek Ls. Kiamitia Buda UPPER CENOMANIAN Del Rio Georgetown LOWER CENOMANIAN VRACONIAN FREDERICKS- BURG Goodland Walnut Edwards Comanche Peak Walnut ALBIAN TRINITY Paluxy Glenrose (Basement Sands)1 Glenrose Travis Peak APTIAN PENNSYLVAN- IAN Unconformity PENNSYLVANIAN is about 110 miles in Texas and 100 miles in Oklahoma. The outcrop is S- shaped, and north and west of its limits in North Central Texas the forma- tions are eroded away; while east and south of the outcrop, the Weno- Pawpaw rock sheet continues underground for an unknown distance, being buried beneath the more recent Comanchean and Cretaceous strata. This concealed extension of these formations still awaits exploration by means of detailed well logs and the examination of samples from drillings. The formations show distinct north-south changes along their outcrops and equally distinct east-west changes. As a whole, they thicken moderately from the Brazos river (near Blum) north to the Red River (north of Gainesville) , and thence eastward down the Red River valley through Den- 'See also: Bose, University of Texas Bulletin, 1902, p. 16, fig. 1. 2The Comanchean sea was transgressive northwards over much of Central Texas, and the Basement sand is not a single formation, but at different places is the time equivalent of various off-shore formations. Hi no and Pawpaw Formations 11 Fig. 1. Map of Texas and part of Oklahoma, showing outcrops of the Weno and Pawpaw formations and the lithological facies of the Pawpaw formation. SI— Sandstone and Ironstone; Cl— Clay; M— Marl; LS— Limestone. 12 University of Texas Bulletin ison and Bennington they thicken rapidly ; so that by inference the main thickening is ENE. and the lines of equal thickness run about 60° E. of N. Southward from the Red River in Cooke County the Weno and Pawpaw formations thin gradually to at least the Colorado River where they are probably represented by strata lying near the top of the Georgetown lime- stone. The two formations behave very differently over the area men- tioned. The Weno formation, south of the change of direction of its out- crop in Cooke County decreases slightly in thickness, from about 75 feet near Gainesville to 65 feet near Fort Worth, 60 near Riovista, 40 near Waco, and 20(?) near Georgetown. The Pawpaw clay on the other hand, thins more rapidly from the Red River southward. Near Cedar Mills, Cooke County it is 60 feet thick, in Denton County 40 feet, at the north border of Tarrant County 27 feet, on Sycamore Creek near Fort Worth 24 feet, at the south border of Tarrant County 12 feet, at Riovista 5 feet, at }Blum 3 feet, and near Waco about 2 feet thick. This thinning is a part of the general thinning southwards of the softer formations of the North Texas Washita, which south of the Brazos are represented in the George- town limestone, as is observable in the Kiamitia marl, Duck Creek marl, Denton marl, Pawpaw clay and Grayson marl. The alternate harder for- mations, the Duck Creek limestone, Fort Worth limestone, Weno limestone, Mainstreet limestone, undergo proportionately less thinning southwards and hence contribute relatively larger components to the Georgetown lime- stone. There are equally distinct differences of lithology and facies, which are presented later. The present paper is only an introduction to the large and interesting Weno and Pawpaw faunae, the majority of whose species are still unde- scribed. Much collecting and further study is required before any attempt can be made towards a monographic treatment of these fossils. It will be noted that the limits set in this paper coincide with the boundaries of hori- zons 25 to 33 inclusive, of Adkins and Winton's preliminary section of the North Texas Washita division.1 1 Adkins and Winton, Paleontological Correlation of the Fredericksburg and Washita Formations in North Texas. Univ. Texas Bull. 1945, 1920. STRATIGRAPHY The stratigraphy of the Weno and Pawpaw formations involves the re- gional stratigraphy of the Comanchean area north of the Brazos River, and accordingly, certain lithological and structural features of this region will be described. In almost the whole region in question, along the line of outcrop of these two formations between the Brazos and the Red Rivers, the Comanchean sediments are deposited over a large geosyncline whose axis is transverse to the direction of the Comanchean outcrops — i. e., roughly northwest- southeast — and whose bulk was largely filled in by pre-Comanchean depos- its. However, there is a feeble surface reflection of this buried structure, which influences the thickness and lithologic characters of all Comanchean deposits, including the Weno and Pawpaw formations. The north edge of this deep trough is near the. Red River and the south edge is south of the Brazos ; the north slope is steep and the south slope more gentle. This de- pression, in which the Fort Worth region is located will be called the Fort Worth geosyncline. ROCKS UNDERLYING THE WENO AND PAWPAW FORMATIONS PRE-COMANCHEAN Its extent may be indicated by the meager data available on the under- ground position of the Ellenburger limestone. At Muenster, Cooke County, it was reached at a depth of about 1800 feet, or 1050 feet below sea level. At Myra, Cooke County, the Ellenburger was reached at a depth of 1640 feet below the surface or about -900 feet (sea level).1 In the Polytechnic (Byrens-Burchell No. 1) well near Fort Worth, the Ellenburger if present lies below -3950 feet, at which level the Bend has probably not been reached. The difference in elevations of the last two subsurface points is 3050 feet which represents the minimum change of elevation of the first Ellenburger reached between Myra and Fort Worth, in case the Ellenburger is present at the latter place. Coincidentally the thickness of Pennsylvanian deposits is not more than 600 feet at Myra, but has increased to at least 3600 feet at Fort Worth. Other wells in Tarrant and nearby counties have penetrated similar Pennsylvanian material. Farther south there is doubt that the Ellenburger is present. In the Hillsboro well the pre-Cambrian rocks were said to be reached at a depth 'Matteson, Econ. Geol., XIV, No. 2, p. 1919. 14 University of Texas Bulletin of 2100 feet, apparently without intervening Ellenburger, and at Waco th,e pre-Cambrian is present at about 2500 feet. However, at points still farther south and southwest, as at Gatesville and Leander, the Ellenburger is present but thin, and overlies pre-Cambrian shales or slate-graywacke which near Leander are stated to be identical in appearance with the Virginia shales and to be of upper Huronian age.1 At Georgetown, Leon Springs and Camp Bullis,2 the Trinity directly overlies the pre-Cambrian schists;3 the depths of the contact are respectively 1100 feet, 1015 feet, and 1790 feet. The depression which is triangular shaped and narrower to the north- west, is flanked to the north, at least in Cooke County, by a structurally high area of Ellenburger at -900 feet, and a thin Pennsylvanian ; and to the west by the structurally high Bend Arch in which the -3000 and -3500 Ellenburger contours have a trend east and south.4 Whether this Ellenbur- ger depression opens to the southeast or to the northwest is not known to me. It was, however, invaded by the Pennsylvanian seas which deposited in its central part at least 3600 feet of sediments, and left a surface which was more largely levelled than the original floor. Upon this surface the Comanchean sea transgressed from the southeast, depositing sediments which still show a feeble reflection of the underlying geosyncline. COMANCHEAN THICKNESS CHANGES Any pre-Comanchean ridges and valleys over which the Comanchean seas spread would be indicated by deposition which is thicker in the valleys and thinner over the crests. If therefore we identified a regional thinning of the beds in two directions from a given location, this might be attributed to deposition on two sides of an existing valley in the ocean bottom, whether originally this valley was erosional or synclinal. This lensing is evident in the Comanchean formations, and particularly in the lower ones (Glenrose, Paluxy) . For example the Glenrose fills in much of the depression by lens- ing; at Decatur it is about 35 feet thick but at Fort Worth about 475 feet, aBy Professor A. W. Johnston, oral communication. 2Sellards: The Geology and Mineral Resources of Bexar County, Univ. Texas Bull. 1932, pp. 19-20. 'These facts were discovered by Dr. J. A. Udden, who has kindly permitted their use here. 4SelIards: On the Underground Position of the Ellenburger Formation in North Central Texas, Univ. Texas Bull. 1849, 1920. Weno and Pawpaw Formations 15 and is increasing southeastward at the rate of about 8 feet per mile. (Hill). Likewise the Paluxy entirely disappears to the south. There are in addition two complicating circumstances, which affect the thickness and lithology, general regional thickening and depositional facies. The Fredericksburg division increases steadily in thickness from the Red River to beyond the Rio Grande. Its marl and marly limestone facies persist at most levels to APPROXIMATE THICKNESS OF THE COMANCHEAN FORMATIONS OF NORTH TEXAS, IN FEET t FORMATION » § Bryan and Marshall ? Counties, Oklahoma | Grayson County, Texas ^ § Cooke County •+ x => Denton County o Tarrant County Parker County D = Johnson County 5 P 5 Hill County -f Buda Grayson 50 50t 60 82 80 100 Mainstreet .... 5 10 15 40 50 50 50 35J Pawpaw 56 50 45 27-40 12-27 9 18 5 Weno 114 125 110 ' ro-ioo 62 40 25 Denton 25 25 25 25 25 20-26 5 Fort Worth 30 30 30 30 32 30 25 27 25 Duck Creek marl . . . Duck Creek limestone Kiamitia 40 100 130 60 130 61 30J 50J 40 30{ 50t 30-40 22 45 27-31 201 40 f 30 20 40 18 50 19 Goodland 16 12-20 19 117 Edwards 20 35 40 Comanche Peak .... 120 105 150 Walnut 8 (5) 5-15 ] 125-150 150 100 150 Paluxy 150 150 90 150 Glenrose ? 470 100-300 400 -500 Basement Sand WASHITA(exclu- s i v e Woodbine . . FREDERICKS- BURG 250 550J 25? 250 541J 50 200J 430 25? 200? 394 150J 374 242 150J 120 290 150 338 330 164f 350 TRINITY ? 200? 770J 650 COMANCHEAN... 825 841 655 1386 ^Approximate thickness. 16 University of Texas Bulletin • the region between the Brazos and the Colorado Rivers. South and west of this region the Rudistid facies invades the Fredericksburg division, begin- ning with the level representing the top of the Edwards limestone (see page 24). The Rudistid facies is characterized by considerable thickness of indurated massive limestone, so that southward as this facies vertically invades the stratigraphic column the invaded formations thicken, Rough estimates of the thickness of this division are: Red River (Denison, 50 feet ; Goodland, Oklahoma, 25 feet) ; Trinity River (Fort Worth), 242 feet; Colorado River (Austin), 350 feet. And for the Washita division: Den- ison, 541 feet; Fort Worth, 374 feet; Austin, 220 feet. In the following table of approximate thicknesses it should be noted that the basal Comanchean deposits are transgressive northwards in such a manner that we do not know with certainty what part if any of the Base- ment Sands of Cooke, Grayson and Denton Counties is of Trinity age. The lowest determined Comanchean fossils in this area indicate the level of Exogyra texana and its varieties of Walnut age. In the Duck Creek forma- tion of the table the "marl" is taken to be the portion above the Mineralized Ledge1 (Stratum 17) of the Fort Worth region, i. e., above the horizon of abundance of Scaphites worthensis. LITHOLOGICAL CHANGES The lithology of the Washita division is diverse and each formation must be considered separately. However, it is generally true in North- Central Texas that the formations decrease in thickness southwards to the Brazos-Colorado divide south of Waco, Texas ; these changes in thick- ness and lithology may be considered as a unit, and are related to the depositional conditions in the large North-Central Texas trough already re- ferred to. Crossing the Brazos-Colorado Divide in which the thinned Penn- sylvanian and Ellenburger and pre-Cambrian floor are structurally high, there is in the Cretaceous another set of thickness changes which for cer- tain formations, notably the Buda, amount to a regional increment in thickness as far south as the turning point of the Washita outcrops in Bexar County. Westward from this point there appears a little known set of changes in thickness and lithology of these formations. In West Texas again, the northern, near-shore facies (Cerro de Muleros, Finlay Moun- tains, Kent, Sierra Blanca) passes quickly into the southern, massive limestone, in part rudistid facies (Shafter, Terlingua, Fort Stockton, Shef- field) and the Texas and Pacific Railway is approximately the boundary line between these two facies. The transition zone from the Edwards 1Winton and Adkins: The Geology of Tarrant County, Univ. Texas Bull. 1931 pp. 42-43. Weno and Pawpaw Formations 17 limestone level passes between Fort Stockton and Sheffield and eastward to a point near Pecos, thence some distance north of Coke and Runnels coun- ties, north of the Central Mineral Region, and approximately to the north- ern border of Hood County, near Comanche Peak. Here the Edwards out- crop disappears eastward under the later formations. An extended study of the rudistid facies will be necessary to define this boundary line pre- cisely ; but it is cited here as an illustration of the type of lithological vari- ations seen within the extent of the Texas Comanchean outcrops. For the other Washita formations likewise, much field work will be necessary to map even approximately their different lithological facies ; accordingly the following summary of these formations is brief and condensed. GRAYSON FORMATION Sandstone facie*: Unknown. Clay facie*: Upper half of the Del Rio Clay (approximately the Gryphea mucronata zone, south of the Brazos River). The middle member of the Grayson is a clay as far north as Denton County, Texas. Marl facie*: Near Bennington, Durant and Bokchito, Oklahoma, Denison, Fink, Gainesville, Denton, Fort Worth, and Burleson, Texas. This is the pre- vailing facies along the outcrop. The eastermost exposure in Central Texas is east of Roanoke, Texas, where the few, insignificant limy seams seen in the Fort Worth region are represented by eleven conspicuous limestone strata. There is little doubt that this formation grows rap- idly more calcareous eastward and southeastward, and that its limestone facies lies in this direction from the outcrop in North-Central Texas and not far from the outcrop. Passing down the Red River valley, however, this does not hold, for the formation is marly in the Tishomingo quadrangle and near Bennington, Oklahoma, where it has essentially the same lithology and fossils as in Tarrant County, Texas. WEST TEXAS In the Cerro de Muleros section, Bose's subdivision 81 consisting of yellow marls containing Schloenbachia sp., Pecten subalpinus (Bose), Exogyra whitneyi Bose,2 Hemiaster calvini Clark, Protocardia texana (Conrad), and Enallaster bravoensis Bose, is Grayson. It overlies the Mainstreet formation, here a sandstone, and underlies subdivision 9, a 'Bose: Inst. Geol. Mex. Bol. 25, p. 27-28. 2B6se: Univ. Texas Bull. 1902, p. 10. 18 University of Texas Bulletin limestone which may be either Grayson or Buda, probably the latter ; this underlies the Woodbine (Dakota) sandstone. The Kent section contains equivalents of Weno and Pawpaw in division 3 of Durable and Cummins1 section, which however does not permit of more precise definition. A north-south line drawn two miles east of Roanoke, Denton County, therefore delimits the marl facies of the Grayson from the transitional beds to the limestone facies, since east of this line the Grayson becomes calca- reous. This line however probably turns east since on going down the Red River valley it leaves the marl facies of the Grayson to the north at seen at Denison, Bennington and numerous other places in Southern Oklahoma. What relations exist east and south of these points depends on well records not yet investigated. South of the Brazos River near Waco there is at the Grayson outcrop a transitional zone to the southern clay facies (zone of Gryphea mucronata, upper half of the Del Rio Clay) which continues west- ward to the El Paso region. The sand facies is unknown but is to be ex- pected in the removed areas of North Central Texas, in the isolated Upper Washita remnants of the Panhandle not yet investigated, and in the Tu- cumcari region. Limestone facies: The limestone facies, on the other hand, lying southwards in Sonora and Chihuahua is still unidentified in Texas, except at one point, the Mariscal Mountains, at the south tip of the Big Bend region.2 MAINSTREET Sand facie*: At Cerro de Muleros, near El Paso, Texas ; apparently near Santa Rosa, New Mexico (Dr. Bb'se) . Clay facies (Del Dio Clay, in part) : The Del Rio Clay is poorly known, and therefore its correlation is tentative. It is equivalent to the Grayson and the upper part of the Mainstreet, and contains the following fossil levels : (1) Nodosaria texana Conrad. A zone of abundance above that of Exogyra cartledgei Bose3 in the upper 30 feet of the formation, which at Shafter reaches a thickness of 190 feet. Below this zone of abundance Nodosaria is scattering. (2) Gryphea mucronata Gabb. Upper half of the Del Rio Clay. (3) Exogyra anetina Roemer. Rare near the middle of the clay in tumble and Cummins: Amer. Geol., xii, 1893, 309. 2Udden, Baker and Bose: Univ. Texas Bull. 44, 1919, p. 76. 3B6se, Univ, Texas Bull, 1902, Weno and Pawpaw Formations 19 West Texas, abundant lower; in Central Texas (South Bosque, Round Rock, Austin) it is abundant in the basal half of the formation but rare or wanting above. It also occurs in the top of the Georgetown limestone at Austin. (4) Turrilites brazoensis Roemer occurs in the lowest five feet of the Del Rio Clay at South Bosque and at Austin ; its main zone of abundance is in the top of the underlying Georgetown limestone. Zones (1) and (2) are Grayson; zones (3) and (4) are Mainstreet; or briefly the upper part containing Gryphea mucronata is Grayson, and the lower part containing Exogyra arietina is Mainstreet. The Mainstreet equivalents locally have sandy levels in Central Texas, as for instance at the top of the Georgetown limestone at South Bosque and in the E. arietina slabs at Austin. Westward from the turning point of its outcrop in Bexar County the Del Rio becomes sandier and more flaggy and contains sandy slabs with Nodosaria and other fossils. At the south end of the Quitman Mountains the Del Rio is transitional, showing a mixture of sand and clay facies, and at Cerro de Muleros the Mainstreet, represented by Bose's sub- division 7 is sandstone. North of the turning point the typical Central Texas section continues to the Brazos, where the Del Rio differentiates into two portions by the intercalation of limestone strata basally; this basal part becomes upper Mainstreet and the upper marlier part becomes Gray- son. The lower Mainstreet however continues as a limestone into Central and West Texas. Marl facie*: The upper Mainstreet formation in McLennan County is transitional from clay to marl, and at South Bosque is rather calcareous. North of the Brazos this calcareous marl contains limy seams which become more prom- inent and take on the interbedded appearance of the Mainstreet limestone of North Texas. Limestone facie*: The typically developed Mainstreet limestone between the Brazos and the Red Rivers shows this lithological facies. There is considerable inter- bedded marl as far north as Gainesville. Eastward from Gainesville, down the Red River Valley, at Cedar Mills, Denison, Bennington, Bokchito and near Hugo, the marl is more reduced in amount, and the formation consists of compact, slightly marly, massive shell breccia or indurated limestone with typical Mainstreet fossils. 20 University of Texas Bulletin PAWPAW FORMATION The Pawpaw formation shows along its north-south outcrop an almost idealized sequence of marine facies. Sand facies: Red River Valley, as far south as the southern border of Cooke County, Texas. Clay faciet: Denton, Tarrant and Johnson counties, Texas, to near Riovista. Marl faciei: Johnson and Hill counties, Texas. Limestone facies: The equivalents of the Pawpaw south of the Brazos are questionable. If it is represented in this region, it is the upper part of the Georgetown limestone. (See page 11.) In West Texas its exact equivalent is unknown. At Cerro de Muleros however a distinct Weno and possibly Pawpaw fauna are present in Bose's subdivision 6, but not enough distinctive Pawpaw species are recorded to decide how much of this subdivision represents it. A hiatus at the base and at the top of the Pawpaw has been noted by Stephenson,1 near the Red River, but it is unlikely that this accounts for any great thickness of Wash- ita sediments. WENO FORMATION Sand facies: There is sand in the upper half of the Weno, in the Red River Valley, Denison, Cedar Mills, Gainesville, Texas. In the lower half of the Weno : unknown. At Tucumcari, New Mexico, Dr. Bb'se found a sandstone, prob- ably Weno-Pawpaw, containing Ostrea quadriplicata Shumard, TurriteUa sp., Protocardia multistriata (Shumard), Protocardia sp. aff. texana (Conrad), Gryphea dilatata Marcou2 and other fossils. Clay (shale) facies: Red River Valley, Gainesville and Denison, Texas. Contains a few thin ironstone seams; southward and to a less extent eastward this facies be- comes marly and is intercalated with thin limestone seams. Marl facies: Denton, Tarrant, Johnson and Hill counties, Texas. The upper half of the Weno is limy at places (as Fort Worth) where the lower half is marly. The formation is prevailingly of limestone throughout, south 'Stephenson: U. S. G. S., Prof. Paper 120-H, p. 143. 2Marcou: Geology of North America, plate IV, figures 1, la, 3, 1842. Weno and Pawpaw Formations 21 of the Brazos River. In West Texas at Cerro de Muleros, the Weno is rep- sented in Bose's subdivision 6, which consists of marls, sandstone and lime- stone. This series is therefore composite and transitional, like the Weno at Gainesville and Denison, and contains many identical fossils. Limestone facies: Portion of the Georgetown limestone near top, south of the Brazos. An indurated, massive limestone facies is unknown but probably lies to the east and south of the outcrop in Central Texas. DENTON FORMATION Sand facie*: Unknown. Clay facies: From Blue Mound, near Haslet, Tarrant County, Texas, northward to Denison. Contains pyrite and crustacean fauna. Marl facie*: In North-Central Texas along the outcrop the marl facies appears below Blue Mound, just north of Fort Worth and continues southward. In southern Oklahoma, the Red River Valley and Central Texas north of the Brazos, this formation is a clay, slightly arenaceous at the base and capped by shell conglomerate. This conglomerate is much more conspicuous at the Red River than at Fort Worth and southward, where it has largely disappeared, leaving a very shelly marl. South of the Brazos River, near Waco, there is a transitional zone between the marl and the limestone facies. At Cerro de Muleros a portion of subdivision 5 is a gray marl containing great numbers of Gryphea washitaensis Hill, and represents the Denton. Limestone facie*: The portion of the Georgetown limestone which represents the Denton formation is a consolidated shelly limestone with very little calcareous cementing material, and usually massive without marl interbedding. It extends from a point near Waco southwards to the turning point of the Comanchean outcrops in Bexar County and thence westward to beyond the Pecos River. In the El Paso region, however, the equivalent to the Denton belongs to the northern (littoral-bathyal) facies and is marly as in North Texas. FORT WORTH FORMATION This formation is calcareous over all of North and Central Texas but is somewhat marly in the Red River valley and is prevailingly marly near El 22 University of Texas Bulletin Paso. A line connecting these two areas will give very roughly the boun- dary between the marl and lime areas. Sand faciet: Unknown. Clay facie*: Unknown. Marl facie*: Cerro de Muleros, near El Paso, gray to bluish marls ; Denison and east- wards, marly limestone and marly interbedding. Limestone facie*: South of the Red River and throughout North and Central Texas at the outcrop. The middle portion of the Georgetown limestone represents this facies. A deeper sea subphase found in southern Trans-Pecos Texas con- sists of hard, crystalline, sparsely fossiliferous, relatively pure, fine grained lithographic limestone, which composes most of the Georgetown and Buda. This is the purest and probably the deepest sea deposition known for this formation. DUCK CREEK (Upper) Sand facies: Unknown. Marl facie*: • This group of strata is prevailingly a calcareous marl and contains the least limestone at Gainesville. At Fort Worth it has only slightly more lime than at Gainesville, while at Denison and at Caddo, Oklahoma, it is distinctly more limy. The change from marliness to liminess therefore appears to be in this region at least largely an east- west change. The Duck Creek marl thickens to the northwest, being thickest near Denison and thicker in the Tishomingo than in the Atoka area. Limestone facie*: South of the Brazos-Colorado River divide, the Duck Creek marl is im- bedded in the base of the Georgetown limestone, where it is a marly im- pure limestone. The situation in West Texas is unknown. DUCK CREEK (Lower) Sand facies: Unknown. There are some bituminous sandy layers in the Duck Creek in Cooke County, Texas, but these appear to be local. Shale (clay) facie*: Seen at the type locality, three miles north of Denison, Texas. This shale is somewhat calcareous and is transitional to a marl. Weno and Pawpaw Formations 23 Marl facie* : This facies invades the limestone series at Gainesville, Texas, where all of the lower Duck Creek except the basal ten feet is prevailingly marly. Probably the removed portion of the Duck Creek west and north of the outcrop was prevailingly marly. Limestone facie*: Extends from Denton County southward to the turning point of the Comanchean outcrop in Bexar County, and thence westward to the Trans- Pecos region. The group of strata is composite and at a given point is more marly above than below. For instance, at Denison the Hamites and Desmoceras zones are prevailingly limy marl with some blue shale, and at Denison the zone of Desmoceras brazoense is marly at the top; at Fort Worth the section is limestone to the top of the Schloenbachia trinodosa horizon and limy even above this ; while below the Brazos the whole lower Duck Creek section becomes limy. South of the Brazos the Duck Creek formation lies at the base of the Georgetown limestone where it is a chalky white indurated rather un- fossiliferous limestone, differing considerably in appearance at Austin and at Georgetown, Texas; while west of the southern turning point of the outcrop it becomes a hard, crystalline, consolidated, sparsely fossilifer- ous limestone. At Cerro de Muleros near El Paso, on the contrary, the northern littoral facies is present as at Gainesville and Denison and this level is represented by a series of clay, marl and limestone, which repre- sents a transitional facies. Vraconian faunae from Chihuahua and Zaca- tecas (p. 60) represent in part this stratigraphic level. KIAMITIA FORMATION Sand facie*: Unknown. Clay (abate) facie*: From near Primrose, southwestern Tarrant County, south througn Johnson County to beyond the Brazos. This formation at Blum, Hill County, is a yellowish clay 19 feet thick. This facies contains a con- spicuous limonite fauna, Schloenbachia, Area, small gastropods and pelecy- pods and other fossils. Marl facie*: Southern Tarrant County to between Gainesville and Fink. The forma- tion is increasing in thickness northwards and as the clay facies disap- pears, flag layers enter first as limestone in thin sheets and farther north as shell conglomerate sheets. The bulk of the formation is marl, and the limonite fauna has largely disappeared. 24 University of Texas Bulletin Lime facies (conglomerate): Fink, Grayson County, Texas, to east of Hugo, Oklahoma. Coincident- ally on passing eastwards and northwards from the marl facies the scat- tered shells in the formation become consolidated into conglomeratic sheets with shelly marl between, and these predominate at Gainesville and Deni- son. Turning east down the Red River Valley the thickness of the Kia- mitia and the amount of this conglomerate greatly increase. Near Hugo, Oklahoma, the Kiamitia shell conglomerate is about 150 feet thick and is extensively used for crushed rock. This formation is a shallow water oyster bed deposit of mixed Fredericksburg and Washita fossils, mainly the former. The formation disappears at the Brazos-Colorado uplift, and in West Texas its relations are unknown. EDWARDS FORMATION The Fredericksburg Division also must be considered sectionally, since its various parts behave differently as to their changes of thickness and lithology. Sand facies: Unknown. Clay facies: Unknown. Marl facies: Unknown. Bose's subdivision 3 at Cerro de Muleros contains some marl, but this subdivision is not positively known to be Edwards. Through- out the Red River region and North-Central Texas, the top of the Good- land, which is thought to correspond to the Edwards, is a non-marly lime- stone, usually massive and sometimes crystalline. North of Sheffield and Fort Stockton, the Fredericksburg is stated to be prevailingly marly. Limestone facies: This is known from Fort Worth south to the turning point of the out- crop in Bexar County, and thence west to El Paso. The Red River ex- tension of this level is not identifiable with certainty because it is not clear whether the 12-20 feet of white limestone at the top of the Fredericks- burg division as seen at Denison or north of Goodland, Oklahoma, repre- sents only the Edwards or also in part still lower Fredericksburg. The Edwards is less than 10 feet thick at Fort Worth; it is 33 feet thick at Comanche Peak, and southwards thickens rapidly. Rudistid facies: The Rudistids invaded Texas most widely in upper Fredericksburg time, when they were scattered as far north as Fort Worth ; however, they are very rare and inconspicuous north of the Brazos, in Central Texas. In Weno and Pawpaw Formations 25 West Texas they are reported as far north as Bailey County, and they are common in Coke and Runnels counties. In Trans-Pecos Texas, the Texas and Pacific Railway roughly divides the southern rudistid facies of the Edwards from the northern littoral facies. The rudistids are rare or wanting at Cerro de Muleros, Kent, Sierra Blanca and the Finlay Mountains ; and present at points between these and the Rio Grande. Gabb1 describes from the Sierra de las Conchas near Arivechi, Sonora, fossils which if correctly identified include among diverse stratigraphic levels that of the Edwards limestone ; the facies represented is unknown to me. Felix and Lenk'- also record the great extent of the Fredericksburg reef facies in Mexico. WENO AND PAWPAW FORMATIONS The influence of the underlying syncline on the deposition of these two upper Washita formations is small, due to their small thickness. However, they show an appreciable syncline in the Fort Worth region, and a con- spicuous thinning southward. Since the maximum rate of change of thickness, like the maximum change in lithology, may not coincide in direction with the outcrop, the formation along the outcrop will in general show only a greater or less north-south or an east-west component of change in thickness or lithology and the maximum change will be in a direction lying at an angle to the outcrop. THICKNESS CHANGES North-South Changes This is true of the north-south outcrop of the two formations, which does not exactly coincide with the direction of greatest thickness change. The Weno and Pawpaw strata outcrop in a line passing about a mile east of Gainesville, Cooke County, and thence nearly south to near Denton; thereafter the boundary between the two formations runs near Fort Worth, west of Cleburne, Riovista and Blum. The outcrop thus from the Red River to the Brazos has a general trend of east of north, while the direction of greatest thickness change is slightly east of north. (See figure 3). 'Gabb: Pal. Cal., vol. 2, p. 257 ff. 2Pelix and Lenk: Beitr. z. Geol. u. Pal. d. Rep. Mex., II, p. 28. 26 University of Texas Bulletin East-West Changes (North Texas and Oklahoma) In the whole Red River region these two formations at their outcrops maintain an almost uniform thickness, but they are slightly thicker east- ward as far as Choctaw County, Oklahoma. Their behavior east of this point is unknown to me. TABLE OF APPROXIMATE THICKNESS OF WENO AND PAWPAW FORMATIONS Weno Paw- Locality Lower Upper Total paw Denison 45 80 125 60 Gainesville 40 70 110 44.8 Blue Mound (Haslet) 27.3 Fort Worth 12.7 49.6 62.3 24.6 Riovista '. 10 25 35 5.0 LITHOLOGICAL CHANGES The Weno and Pawpaw formations are marked by striking lithological changes which produce along their outcrops localized lithological regions each with a characteristic fauna. The Pawpaw formation, and to a less extent the Weno, passes from north to south along its outcrop through a "typical" series of lithological fades— sand-clay-marl-limestone, which aside from various complicating factors of deposition is usually taken to represent a progressive series of marine facies from near-shore .to off- shore conditions. Likewise the problem of localized faunales is vividly impressed upon one by the situation in the Pawpaw clay (as also in the Weno), where within a few miles one fauna largely disappears and an equally rich and varied, but different one occupies its stratigraphic posi- tion. For example the Gainesville-Denison fauna (Nacreous, Area), the Fort Worth fauna (Turrilites, Engonoceras, Hamites, Scaphites) and the Riovista fauna (Flickia, echinoids) of the Pawpaw formation represent three different marine facies. The narrow ribbon-like outcrop of these formations in North Central Texas and Southern Oklahoma gives only a limited opportunity for the study of these different marine phases, but the following regional differences in the sediments of these formations are ap- parent. Weno and Pawpaw Formations PAWPAW FORMATION Nature of Material Locality of Outcrop 27 (a) Semi-consolidated sandstone and ironstone Choctaw county, Oklahoma Marshall county, Oklahoma Bryan county, Oklahoma Love county, Oklahoma Grayson county, Texas Cooke county, Texas Faciea of Marine Deposition (b) Clay with sandy layers f Denton county | Tarrant county (c) Marl with limy layers. . . f Johnson county { Hill county (d) Limestone South of Brazos River Neritic Bathyal Deeper Sea (a) (b) (c) UPPER WENO stone | Cooke county Neritic Marl with lime layers Denton county Bathyal Limestone Tarrant county and south wardDeeper Sea (in part Zoogenic) LOWER WENO (a) Shale with sand layers Red River region Neritic (b) Marl and limestone layers Cooke county to Brazos RiverBathyal (c) Limestone South of Brazos River Deeper Sea PAWPAW FORMATION Eastward from the turning point of the Comanchean outcrops in the Red River uplifted area near Orlena, Cooke County, Texas, the Pawpaw is a ferruginous sandstone or an unconsolidated sand. This outcrop runs down the Red River valley in a direction a little south of east, lying in Cooke and Grayson Counties, Texas, and in Love, Marshall, Bryan, and Choctaw Counties, Oklahoma. Sandstone Facies (a) (Semi-consolidated Sandstone and Ironstone) In general, the Pawpaw formation is prevailingly sandy and iron bear- ing at its outcrops north and east of the south border of Cooke County, Texas. 28 University of Texas Bulletin Near Gainesville, the formation is a series of thickbedded, hard, ferru- ginous sandstones with interbedded, laminated impregnated sandy layers and semi-consolidated iron-impregnated sand. The layers are locally a shell conglomerate containing great quantities of casts of Area, Turritella and other bivalves and gastropods. The basal layers are characterized by an abundant pyrite fauna. Turrilites, Scaphites, Hamites and echinoids are rare or absent. This type of lithology continues around the turning point of the Comanchean formations south of Orlena to a point near Potts- boro; and at Denison the Pawpaw formation is almost entirely a coarse consolidated brownish-red sand with few fossils. At Durant the formation is similar to the Denison exposures. Eastward through Bennington and Bokchito the sandy phase continues, and is included in the Bokchito for- mation of Taff. SECTION OF SUGAR LOAF MOUNTAIN, BRYAN COUNTY, OKLA-HOMA Section 22, R. 12 E., T. 5 S. (furnished by W. M. Winton) MAINSTREET: Limestone, iron stained, old cap of hill, practically removed by weathering. Feet PAWPAW: Massive yellow red sandstone, soft in fresh exposures, indurated where long exposed ; no fossils seen 5.0 Soft limonitic sand ; no fossils seen 30 . 0 Ironstone ledge composed of fossils (Area sp., Ostrea quadriplicata, small ammonites, gastropods, etc., a typical Pawpaw fauna) 0.5 Red sand, cross bedded and containing lenticular hard masses of sandstone 10.0 Ironstone ledge composed of fossils (Area sp., Ostrea quadriplicata, am- monites, Nodosaria, etc., a typical Pawpaw fauna) 0.8 Red sand 10.0 WENO: Yellowish hard limestone with typical Weno fossils 0.8 Soft marl ; no fossils seen 0.3 Very hard massive limestone, pinkish in color. Large numbers of fossils having same hardness as matrix and giving uniform fracture. Ledge forms conspicuous topographic break traceable for miles. Schloenbachia sp. M., and other typical Weno fossils 1.9 Soft marl 15.0 Limestone ledge sandy; no fossils seen 1.0 Soft marl with a few thin limestone ledges, each less than 0.5 feet thick 95.0 DENTON: Conglomerate of Gryphea washitaensis, Ostrea carinata, and other Denton fossils. Typical Denton marl ("Caddo" limestone of Taff, top). Ex- posed, about < 2.0 Weno and Pawpaw Formations 29 In the creek, one-fourth mile west of the mountain, the contact between the Duck Creek marl and the Fort Worth limestone is exposed as at Caddo, Oklahoma. In the second cut 1V£ miles north of Hugo, Oklahoma, there is 10 inches of shell conglomerate containing abundant juvenile and adult Ostrea quadriplicata Shumard, Gryphea washitaensis Hill, Plicatula sp., Pecten subalpinus (Bose), abundant Leiocidaris spines, Corbula littoralis Adkins, and other typical upper Weno fossils as found at Gainesville and Denison. This represents part of the Quarry limestone group. Above it is an iron- stone ledge, 4 inches thick, which is red-stained and conglomeratic and re- sembles the basal Pawpaw as seen at Gainesville. Along the St. Louis and San Francisco Railway track between Benning- ton and Bokchito, Oklahoma, the upper Washita section, Woodbine to Weno, is seen to advantage. The Grayson marl with an estimated thick- ness of 50 feet is well developed with its characteristic fossils.1 The Mainstreet limestone is seen in roadside cuts one mile northwest of Bennington, in the caprock of Sugarloaf Mountain, six miles north of Ben- nington, in the bed of Sulphur Creek, where it forms an extensive pave- ment limestone, and in the railroad cuts nearby, particularly in the long cut running west down to Bokchito Creek, which has it well exposed. Everywhere it is underlain by the brown consolidated Pawpaw sandstone. The nature of the Pawpaw and Weno outcrops in this region is seen from the following section. SECTION OF CUT NEAR SULPHUR CREEK, ON THE ST. LOUIS AND SAN FRANCISCO RAILWAY, TWO MILES WEST OF BENNINGTON, OKLAHOMA MAINSTREET: Feet Brown limestone with Turrilites brazoensis, Pecten subalpinus, Exogyra sp. (large), and ammonites. The top of the exposure is an Exogyra arietina conglomerate. Exposed 2 Brown-blue limestone with irregular sandy inclusions 1 Yellow limestone containing Kingena wacoensis, Ostrea marcoui, and Pecten subalpinus 1 . B 'Taff (U. S. G. S. Geologic Atlas of the United States, Atoka Folio, No. 79) has overlooked the Grayson marl, which in this quadrangle is typically developed as at Denison. It may be seen near the Woodbine ("Silo") sandstone knob mapped by Tafl one mile northwest of Bennington, Oklahoma, where it overlies typical Mainstreet limestone containing Turrilites brazoensis Roemer, Exogyra arietina Roemer and othei distinctive fossils, and contains Gryphea mucronata Gabb, Gryphea, sp. (truncate) Pecten subalpimts (Bose), Plicatula sp., Ostrea sp. aff. subovafa. Shumard, and Kngonoceras sp. This locality is mentioned by Taff, ibid., p. 6. It also forms the overburden in the Mainstreet quarry one mile north of Durant, Oklahoma, where it is very fossiliferous. 30 University of Texas Bulletin PAWPAW: Consolidated brown sandstone, no fossils seen 5 Unconsolidated sand, iron stained 10 Blue jointed clay with scattered Gryphea 10 !s sS ai«HS *3UP!3I 1 i i i ; ; 1 I 1 1 t | 1 1 I«W »na < i : i 1 I 1 I 1 1 l 1 1 1 I 1 1 I «png H i . | 1 ! ! ! o< 0 0 O 1 1 1 uo8JtBa0 H 0 i | i | ! ! <- i < < o i o pumpqi « 1 t M H ! ! oc 5 0 < o ! E o o MBa"Bd o6«!o !« !o ! ! the exceptional variety of gerontic ammonites, especially Hamites; Scaph- ites, Schloenbachia, Desmoceras and other genera are also prominent in the fauna. DUCK CREEK LIMONITE AND PYRITE FOSSILS *Scaphites worthensis Adkins and Winton. *Scaphites sp. aff. worthensis. *Engonoceras sp. Hamites tanima Adkins and Winton. •Karaites spp. *Crioceras (?) sp. •Schloenbachia sp. *Neolobites (?) sp. *Arca sp. *Nucula sp. *Turbo sp. *Lunatia sp. *Cerithium sp. *Nerinea sp. aff. pellucida Cragin *Cinulia sp. *Anchura sp. *Turritella sp. *Nerinea sp. *Placosmilia sp. DENTON CLAY FAUNA The clay facies of the Denton formation extends from northern Tar- rant County (Blue Mound, near Haslet) to beyond Denison. It is char- acterized by a great diversity of small pyrite and limonite ammonites, some of them nacreous, and by many small Crustacea, mainly small pyritic crabs. The ammonites seem more abundant southwards than on the Red River and the Crustacea the reverse. FAUNA OF THE DENTON FORMATION * Limonite or pyrite species. U Upper. L Lower. *Acanthoceras sp. aff. aumalense Coquand *Engonoceras sp. *Mortoniceras sp. 56 University of Texas Bulletin *Schloenbachia sp. *Acanthoceras (?) sp. "Turrilites sp. (?) *Baculites (?) sp. Ophioglypha texana Clark *Starfish sp. (ray) *Goniophorus (?) sp. 2 specimens, one with the shell. Leiocidaris sp. (spine and plate). Leiocidaris hemigranosus Shumard. Hemiaster sp. (plate). Hoploparia sp. Cambarus (?) sp. (like sp. in Gainesville brickyards Weno). Crabs 9 spp. Ostrea quadriplicata Roemer. Ostrea carinata Lamarck. Gryphea washitaensis Hill. Ostrea sp. (small zigzag). Stearnsia robbinsi White (?). Gervilliopsis invaginata White (?) Trigonia emoryi Conrad. Plicatula dentonensis (?) Cragin. *Arca sp. Anomia sp. Plicatula spp. *Nucula sp. *Cardium sp. *Leda sp. *Corbula sp. Pecten sp. aff. inconspicuus Cragin. Crania sp. Dentalium sp. ?Porocystis-like masses. *Natica sp. *Cinulia sp. Fish teeth, vertebrae, skin, plates. GRAYSON FAUNA The pyrite and limonite fauna so far discovered in the Grayson forma- tion is confined to the middle clay member of the formation in North Texas, and includes diverse ammonites, gastropods and pelecypods, as listed below. However, the pyrite fauna of the middle Del Rio clay which occurs in McLennan County and southward is of Grayson age, Weno and Pawpaw Formations 57 and contains some identical species. This latter fauna is well developed on the South Bosque River, five miles west of Waco and includes Turrilites bosquensis Adkins, Flickia ( ?) bosquensis Adkins, Acanthoceras worth- ense Adkins, Schloenbachia spp. and other common Grayson and Pawpaw pyrite species. It is notable that the preservation of this fauna is almost exclusively pyritic. FAUNA OF THE GRAYSON MARL * Pyrite or limonite species. (C) Cidarid zone. (Co) Coral zone. U Upper member. M Middle member. L Basal member. CEPHALOPODS: Turrilites sp. (medium size) (M). "Turrilites sp. aff. worthensis A and W. *Turrilites spp. (M). *Turrilites sp. (whiplash) (M). *ammonite aff. Flickia (small, keelless) (M). *Hamites 3 spp. (M). Acanthoceras ? sp. (Denison, WSA). Acanthoceras spp. Engonoceras spp. (L). *Schloenbachia spp. ECHINODERMS: Hemiaster calvini Clark, starfish sp. Goniophorus (?) sp. cidarid spines 3 spp. (C). Cyphosoma volanum (?) Cragin. Enallaster texanus (?) Roemer. Enallaster sp. aff. traski (?) Whitney. Enallaster sp. aff. bravoensis Bose (?). CORALS: •Placosmilia (?) sp. (Co). GASTROPODS: Cerithium sp. Turritella marnochi (?) White. Turritella sp. Cinulia pelletti Whitney. *Gyrodes (?). "Turbo sp. •Turritella sp. (sharp spired) M. 58 University of Texas Bulletin PELECYPODS: Gryphea mucronata Gabb. Gryphea sp. aff. corrugata Say. Exogyra sp. aff. columbae Sowerby (L). Exogyra n. sp. (Denison, M). Exogyra sp. aff. texana (U, under Buda limestone, Bosque River, W of Waco). Pecten texanus Roemer. Pecten subalpinus Bose. *Arca sp. Ostrea sp. aff. subovata Shumard. Lima sp. (elongate). Lima sp. (quadrate). Lima sp. aff. wacoensis Roemer. Ostrea sp. (saucer). Anomia sp. Plicatula spp. Protocardia texana (?) Conrad. Pholadomya shattucki Bose. Tapes sp. Inoceramus sp. M. Corbula (?) sp. Trigonia sp. Cyprimeria sp. (small). Cyprimeria sp. aff. crassa Meek. *Nucula sp. *Crassatella (?) sp. ("Remondia"). *Barbatia sp. Trigonia sp. (large). *Isocardia sp. Shark teeth, vertebrae, bones. DEL RIO CLAY FAUNA The Del Rio limonite fauna is very widespread in Texas, having been found at Waco, South Bosque, Austin, Quihi (Medina County), Del Rio, Terlingua, and the Solitario. In McLennan County at the base of the Del Rio clay, which corresponds to the middle of the Mainstreet limestone, an extensive pyrite and limonite fauna occurs, including the following: *Exogyra arietina Roemer. *Turritella sp. *Cerithium sp. *Turrilites spp. *Schloenbachia sp. Weno and Pawpaw Formations 59 *Nerinea sp. Lunatia sp. •Natica sp. Goniophorus sp. Pecten subalpinus Bose. Turrilites brazoensis Roemer. The Del Rio pyrite fauna corresponding to the base of the Grayson formation of North Texas has already been noted; it includes: * Turrilites bosquensis Adkins. *Flickia (?) bosquensis Adkins. •Acanthoceras worthense Adkins. *Schloenbachia sp. Exogyra arietina Roemer. Gryphea mucronata Gabb. Gryphea sp. Pecten subalpinus (Bose). The first named limonite fauna with an extensive calcite microfauna immediately overlies the Georgetown limestone and is of middle Main- street age. It is seen at South Bosque, and will probably be discovered at many places in Central Texas. Liddle states that the Del Rio clay throughout Medina County, contains great amounts "of dark brown limonitic fragments and fossils.' Good localities are a small Del Rio inlier four miles slightly west of north of Quihi on the Bandera road, and the main area of exposure just north of the inlier. These localities contain limonitic gastropods, *Turrihtes, *Sca- phites, small ammonites, and loose *Nodosaria. At Loma de la Cruz and other localities in the Del Rio clay lowland two miles south and southeast of Del Rio, the basal clay contains limonitic *Schloenbachia sp., *Hamites sp., *Scaphites sp., *Turrilites (two species), *sp. aff. Flickia ( ?) bosquensis Adkins ; *Pyrina or Cassidulus sp., cidarid sp., *Leda (two species) , *Nucvla sp., *Arca sp. *Plicatula sp. ; *Nerinea sp. (abundant), *Cerithium spp. and other fossils. Along the base of the Reed Plateau, Terlingua, the basal Del Rio clay contains abundant brown limonite fossils, the great majority of which are various species of Turrilites. The fauna includes : *Nodosaria texana Conrad, *T:irrilites (three species), * Acanthoceras sp., *Schloenbachia sp. ; *Nucida sp. 'Liddle, The Geology and Mineral Resources of Medina County, Univ. Texas Bull, (in press). 60 University of Texas Bulletin The Del Rio clay surrounding the Solitario Uplift contains a rich assort- ment of brown limonitic fossils, including *Engonoceras sp., *Turrilites (two species), *Turritella sp., gastropods, *Nucula sp., *Tapes sp., *Nodo- saria texana Conrad, and other fossils. It may be mentioned that these limonite faunae in Texas are not confined to the Comanchean, since & rich fauna was found in the Terlingua beds (Taylor marl equivalent) about five miles north of the crossing of the Alpine-Terlingua road through Terlingua Creek, Brewster County, Texas. This fauna includes: *Turrilites sp., *Baculites sp., *Ptychoceras sp., *Desmoceras sp., *Trochosmilia sp., *Lingula sp., *Lunatia sp., *Natica sp., *Nerinea sp., numerous other gastropods, and fish teeth and vertebrae. Bose1 found a rich Vraconian fauna in limestone blocks covering small hills just west of Camacho, Zacatecas, between this station and the Trin- idad mine, and west of Opal, Zacatecas, iri the core of an anticlinal hill consisting of thin-bedded limestone with lenses and concretions of chert. These fossils are mainly silicified, but are! cited here on account of their striking resemblances to the pyrite fossils described in this paper. The fauna includes typical Vraconian genera, as Phylloceras, Lytoceras, Macro- scaphites, Hamites, Hamulina, Ptychoceras, Diptychoceras, Anisoceras, Turrilites, Baculites, Desmoceras, Acanthoceras, Ancycloceras, Toxoceras, Crioceras, Scaphites, Schloenbachia, Brancoceras and Exogyra. SUMMARY OF PYRITE FAUNAE . The Washita marl and clay faunae contain distinctive assemblages of ammonites, Crustacea, starfishes, echinoids, gastropods, pelecypods, corals, and other fossils. The Crustacea are preserved partly with the original integument and partly with limonite replacement. The other fossils are in part calcitic, but mainly limonite and hematite pseudomorphs and casts of the interior of the -original shell. Ammonites: These are very distinctive for each fauna. Species of Schloenbachia abound in each marl and clay formation. Acanthoceras is found in the Denton, Pawpaw and Grayson faunae, but not in the Duck Creek. Hamites are abundant in the Duck Creek marl and present in the other formations. Turrilites abounds in the Pawpaw and is not known with certainty below it. Flickia, Hamulina, Baculites and Puzosia are known only from the Pawpaw clay. ose, On some new Cretaceous Faunas from Mexico, Univ. Texas Bull, (in press). Weno and Pawpaw Formations 61 TABULATION OF KNOWN AMMONITES OF THE WASHITA PYRITE AND LIMONITE FAUNAE Species Hamites Duck Creek marl 10 Number i Denton marl 1 jf Known J Pawpaw clay 3 Ipecies in: Grayson marl 3 Del Rio clay Turrilites 1? 10 4 1 Acanthoceras 2 2 1 1 Scaphites 2 2 Flickia 1 1? Baculites 1 Schloenbachia 3 1 2 2 1 Mortoniceras 1 2 Puzosia . . 1 Hamulina 1 Engonoceras 1 1 3 1 Crioceras (?) 1 Neolobites (?) . 1 ECHINODERMS: TABULATION OF THE KNOWN ECHINODERMATA OF THE WASHITA LIMONITE FAUNAE Number of Known Species in: Duck Creek Denton Pawpaw Grayson Del Rio Species marl marl clay marl clay ASTEROIDEA: Metopaster 1 • • • • Comptonia 1 • • • • Pentaceros 1 . . genus, indeterminate.. 1 2 1 OPHIUROIDEA: Ophioglypha 1 .. ECHINOIDEAi; Holaster 1 2 1 Hemiaster 2 1? 2 2 Stenonia * • • • 1 Epiaster 1 Enallaster 1 3 3 Goniophorus 1 1 1 1? 1 Goniopygus 1 .. Leiocidaris 1 . . Salenia 1 . . cidarid spines 2 3 'Most of these haVe calcitic preservation. 62 University of Texas Bulletin Of these echinoderms the starfishes and brittle stars have so far been found only in the upper formations, Denton and above. The echinoids also seem more abundant and varied in the Upper Washita; Enallaster particularly shows a development of several species in the Weno and Pawpaw formations. Stenonia supernus (Cragin) is known only from the Grayson marl. Among the small echinoids, Regularia, especially Salenidae, predominate. The Salenidae have a wide distribution and their various species seem reliable as horizon markers. CRUSTACEA : There is a great variety of crabs belonging to many different genera. Of the lobsters a small species of Hoploparia is abundant in the Denton marl. Segments of appendages abound in these four formations; claws are found in the Duck Creek and Pawpaw and rarely in the intervening formations. These Crustacea are for the most part calcareous and ex- cellently preserved. In addition there are known in the Texas Coman- chean, from the Goodland indeterminate limb segments; from the Duck Creek limestone Callianassa sp. claws; from the Fort Worth limestone a lobster related to Homarus (Dr. Shuler) ; and from the Weno, two lob- sters and an indeterminate claw. A crab and a lobster claw have been reported from the Buda. TABULATION OF KNOWN CRUSTACEA OF THE WASHITA PYRITE AND LIMONITE FAUNAE Duck Creek Denton Pawpaw Grayson Species marl marl clay marl ASTACURA: Cambarus ? . . . 1 Hoploparia 1 1 appendages, indet , . . . . . . . 3 species, indet . . . . 4 ANOMURA: Callianassa . 1 BRACHYURA: species indet. PELECYPODA : The Duck Creek limonite fauna is marked by the relative poverty of pelecypods and the relative abundance of gastropods. A small species of Area, abundant in the Pawpaw also occurs in the other formations. Weno and Pawpaw Formations 63 The Pawpaw and Grayson each has a considerable assemblage of small pyritic and limonitic pelecypod casts. TABULATION OF KNOWN PYRITE OR LIMONITE PELECYPODS IN THE WASHITA PYRITE FAUNAE Duck Creek Denton Pawpaw Grayson Species marl marl clay marl •Area 1 1 1 1 •Nucula 1 1 1 1 *Leda . . 1 1 "Corbula .. 1 1 *Plicatula 1221 *Barbatia . . . . ". . 1 *Isocardia (?) .. .. .. 1 *Remondia (?) .. .. 1 1 •Lima 1 1 2 1 GASTROPODA : As may be seen in the following table, a fauna of small gastropods is a feature of the pyrite and limonite fossils in these four formations. In the Duck Creek marl these small limonite gastropods are the most con- spicuous element of the fauna. TABULATION OF WASHITA LIMONITE AND PYRITE GASTROPODS Duck Creek Denton Pawpaw Grayson Species marl marl clay marl •Natica 1 1 1 1 •Cinulia 1 1 1 1 *Cerithium 1 . . . . 1 •Turritolla 1 .. 1 2 *Gyrodes 1 .. .. 1 •Turbo 1 .. 1 1 •Lunatia 2 .. 1 *Nerinea 2 . . 1 *Anchnra . 1 OTHER COMPONENTS: Small corals (Trochosmilia, Placosmilia) occur in the Duck Creek and Pawpaw formations, and probably in the Denton and Grayson. There is a notable abundance of small sharks (Lamna, Oxyrhina, Ptychodus) in the Pawpaw, where teeth, vertebrae, plates, skin and bones are found ; the same fossils are found less abundantly in the other formations in 64 University of Texas Bulletin question. These sharks also occur in the intervening limestone forma- tions but their abundance in the marls and clays testifies to the favorable conditions for their existence. In view of the importance which these pyrite faunae may have for correlation purposes, it is considered useful to refer to certain pyrite faunae of approximately the same age known from Europe and Africa. Of these the Vraconian fauna investigated by Pervinquiere shows the closest similarities to the Pawpaw fauna here described, notably in the ammonites. The bearings of these fossils on the correlation of the Paw- paw formation have been discussed elsewhere (page 42). It is evident that unless conditions for the pyritization of fossils are worldwide at a given time, it is useless to attempt to make exact correlations of Texas pyrite zones with particular zones abroad. Instead, those pyrite fossils which have limited vertical ranges may, like any other such fossil, be used to mark within narrow limits the age of the zone in which the fossil occurs. A list of similar Texas and foreign pyrite and limonite species is added. EUROPE AND AFRICA European Limonite and Pyrite Faunae1 VALANGIAN Sayn2 has described a series of pyritic ammonites from the Valangian of Provence and Dauphine; this fauna consists prevailingly of species of Lytoceras, Phylloceras, Garnieria, Neocomites, Thurmannia, Mortoniceras and Leopoldia. ALBIAN In the Haute-Marne, near Montierender are two gray sand layers with pyritic ammonites, separated by one meter of clayey sand. Upper Level: Lower Level: Hoplites deluci denarius Desmoceras beudanti splendens Hoplites deluci auritus denarius Turrilites catenatus quercifolius Hamites rotundus Douvilleiceras mamillatum lyelli Inoceramus concentricus Hamites alternotuberculatw Nucula pectinata Belemnopsis minimus iHaug: Traite de Geologic, pp. 1232-1298. 2G. Sayn, Les ammonites pyriteuses du sud-est de France. Mem. Soc, Geol. France. No. 23, 1901. Weno and Pawpaw Formations 65 Inoceramus concentricus salomonis Plicatula radiola Nucula pectinata Area fibrosa Trigonia fittoni Dentalium decussatura Solarium moniliferum Cerithium trimonile A.LBIAN In the Rhone basin (les Baronnies and le Diois) the Albian is bathya] and contains a level of small pyritic ammonites: Phylloceras alpinum Tetragonites timotheanus Kossmatella chabaudi miihlenbecki Desmoceras latidorsatum VRACONIAN In the Rhone basin, region of Dieulefit, the Vraconian is represented by black marls with pyritic fossils: Gaudryceras dozei Turrilites bergeri tuberculatus Belemnopsis ultimus Cerithium lallerianum1 Avellana muratelli African Pyrite Faunae ALBIAN In the province of Constantine Blayac2 collected the following species, preserved as ferruginous molds: Upper Level: Lower Level: Tetragonites timotheanus Phylloceras velledae Kossmatella agassiziana Puzosia mayoriana Desmoceras parandieri, etc. paronae Desmoceras beudanti latidorsatum Douvilleiceras mamillatum Turrilites gresslyi JJ. E. Fallot: fitude geologique sur les etages moyens et superieurs du terrain cretace dans le Sud-Est de la France. Ann. des Sciences geol., 1, 268 p., 41 fig., 8 pi., 1885. 2J. Blayac: Le Gault et le Cenomanien du bassin de la Seybouse et des hautes plaines limitrophes (Algerie) C. R. Acad. Sci., CXLIII, 252-5, 1906. 66 University of Texas Bulletin ALBIAN In the province of Algiers, near Aumale, Peron1 found marls with ferruginous fossils: Natica Phylloceras velledae Solarium Pozosia mayoriana Cerithium Desmoceras latidorsatum Nucula Desmoceras beudanti Leda Uhligella dupiniana Astarte CENOMANIAN The Cenomanian is uniformally represented in Northern Tunis by an alternation, indefinitely repeated, of marls and limestones. According to Pervinquiere,2 only the lower part of the stage is fossiliferous. Here a Vraconian fauna is found, with the following species preserved as ferruginous molds: Phylloceras ellipticum? Kossmat Turrilites Bergeri Brongniart — Velledae Mich. var. Seresitensis — Wiesti? Sharpe Pervinquiere — Morrisi Sharpe — Tanit Pervinquiere — Scheuchzerianus Bosc. — decipiens Kossmat — costatus Lamarck Lytoceras Flicki Pervinquiere — Puzosianus d'Orbigny cf. Marut Stoliczka — Kerimensis Pervinquiere — Timotheaum Mayor Forbesiceras obtectum Sharpe — cf. Kingianum Kossmat Saynoceras Gazellae Pervinquiere Hamites simplex d'Orbigny Scaphites aequalis Sowerby — virgulatus Brongniart — obliquus Sowerby — armatus Sowerby — Thomasi Pervinquiere Baculites baculoides Mantell Puzosia Paronae Kilian Puzosia Chirchensis Pervinquiere Mortoniceras Nicaisei Coquand — Mayoriana d'Orbigny — proratum Coquand Placenticeras Uhligi Choffat Tunesites Salambo Pervinquiere — Saadense Th. et. P. Acanthoceras Brottianum d'Orbigny Flickia simplex Pervinquiere — Martimpreyi Coquand Brancoceras Zrissense Pervinquiere — Aumalense Coquand Mortoniceras inflatum Sowerby with its var, — Suzannae Pervinquiere subinflata, spinosa and orientalis Stoliczkaia dispar d'Orbigny Belemites (Hibolites) minimus Lister Pervinquiere3 has described many Cenomanian ammonites from Algeria, some of them ferruginous; the fauna contains Phylloceras, Lytoceras, Hamites, Scaphites, Puzosia, Acanthoceras, Turrilites, Mortoniceras, and several other common genera, and is sim- ilar to that of Tunis. 1A. Peron: Essai d'um description geologique d'Algerie pour servir de guide aux geologues dans 1'Afrique franchise. Ann. des Sci. Geol., xiv, art. 4, 202 pp., figs. 1883. 2Pervinquiere : Et. pal. tun., Cephalopodes, pp. 417-418. 3Pervinquiere, Sur quelques ammonites du cretace algerian. Mem. Soc. Geol. France, No. 42, 1910. Weno and Pawpaw Formations 67 Boule, Lemoine and Thevenin1 cite from Madagascar a series of sandy clays of middle and upper Cenomanian age, containing pyritic fossils. These clays are characterized by Acanthoceras subvicinale B. L. & T., Scaphites aequalis Sowerby, Belemnites fibula Forbes, Ostrea foisseyi Lemoine, and contain Acanthoceras prenodosoides B. L. & T., Phylloceras forbesianum d'Orbigny, P. diegoi B. L. & T., etc. PARALLELS BETWEEN WENO-PAWPAW FOSSILS AND FOSSILS OF THE EUROPEAN AND AFRICAN CENOMANIAN AND VRACONIAN *H. *T. Texas *Scaphites hilli Adkins and*S. Winton •Flickia boesei Adkins *F. *Acanthoceras worthense *A. Adkins •Acanthoceras sp. *A. *Hamitestenawa Adkins and *H. Winton •Hamites sp. *Turrilites worthensis Adkins and Winton *Baculites comanchensis Adkins *Mortoniceras worthense Adkins *Puzosia sp. *Lytoceras sp. *Metopaster hortensae Adkins and Winton *Comptonia- wintoni Adkin Schloenbachia wintoni Adkins Corbula Wenoensis Adkin.' Pinna guadalupae Bose Pecten texanus Roemer Pecten subalpinus Bose Plicatula subgurgitis Bose Ostrea carinata ? Lamarck Ostrea marcoui Bose Gryphea washitaensis Hill Africa (Tunis) aequalis Sowerby Europe S. aequalis Sowerby simplex Pervinquiere martimpreyi Coquand A. suzannae Pervinquiere simplex d'Orbigny H. armatus Sowerby wiesti Sharpe martimpreyi Coquand simplex d'Orbigny H. armatus Sowerby B. baculoides Mantell B. baculoides Mantell *M. *P. L. inflatum var. spinpsum Pervinquiere paronae Kilian marut Stoliczka M. parkinsoni Forbes C. comptoni Forbes S. rostrata C. bicarinata Noetling P. decussata Goldfuss P. alpinus d'Orbigny P. alpinus d'Orbigny P. gurgitis Pictet O. carinata Lamarck and O. frons O. syphax Coquand G. vesiculosa Sowerby 'Boule, Lemoine and Thevenin, Paleontologie de Madagascar, Cephalopodes cretaces des Environs de Diego-Suarez, Ann. de Pal., vol. 1, fasc. 4, pp. 2, 4, 1906. 68 University of Texas Bulletin Helicocryptus mexicanus Bose Holectypus limitis Bose Enallaster bravoensis Bosc Epiaster aguilerae Bose Hemiaster calvini Clark H. radiatus Sowerby H. cenomanensis Gueranger E. lepidus de Loriol E. triangularis d'Orbigny H. latigrunda Peron and Gauthier DESCRIPTION OF SPECIES' CEPHALOPODA NAUTILUS TEXANUS Shumard i860: Nautilus texanus Shumard, Trans. Acad. Sci., St. Louis, 1, 1856-60. 1889: Nautilus texanus Hill, Geol. Surv. Texas, Bull. 4, p. 21. 1893: Nautilus texanus Cragin, Geol. Surv. Texas, 4th Ann. Kept., p. 236. 1895: Nautilus washitanus Cragin, Colo. Coll. Stud., 5, p. 67. 1902: Nautilus texanus Shattuck, U. S. G. S., Bull. 205, p. 34, pi. XXIII, figs. 1-2, pi. XXIV, figs. 1-2. 1920: Nautilus texanus Adkins and Winton, Univ. Texas Bull. 1945, p. 32, pi. 20, figs. 1-2. 1920: Nautilus texanus Winton and Adkins, Univ. Texas Bull. 1931, pp. 58, 61, 66. This is the commonest Cdmanchean Nautilus, and has a known range from the basal Duck Creek limestone (at Denison, Texas) to the Buda limestone (at Austin, Texas). It has a zone of abundance in the top of the Weno limestone, and one in the top of the Fort Worth limestone. NAUTILUS sp. The upper Pawpaw clay contains considerable numbers of small Nautili of a size about one-third that of Nautilus texanus Shumard. These Nau- tili are more closely coiled, have a smaller umbilicus, a much thicker and lower volution, and apparently are smooth. The species is not described here because of the poor preservation of the material at hand. 1Types and figured material are deposited in the Bureau of Economic Geology, Austin, unless otherwise specified in the text. The types at Austin are in a metal locker in the fireproof vault of the University of Texas Library. Most of the photo- graphs were made by Mr. F. Christiansen, Austin, but for some I am indebted to Professor John Davis, Fort Worth. Weno and Pawpaw Formations 6i) AMMONITES1 HAMITES TENAWA Adkins and Winton 1920: Hamites tenawa Adkins and Winton, Univ. Texas Bull. 1945, p. 43, pi. 6, fig. 4. 1920: Hamites tenawa Winton and Adkins, Univ. Texas Bull. 1931, p. 21. 1920: Hamites sp., Winton and Adkins, ibid., p. 69. HORIZON: Pawpaw formation, clay fades, base. LOCALITY : About three miles southeast of Haslet, Tarrant County, Texas (type locality); 714, near Fort Worth, Texas; 723, Glen Garden Country Club, near Fort Worth, Texas. Among several Hamites in the Pawpaw clay is a straight equal ribbed species resembling Hamites simplex. The species and its suture have been figured elsewhere; the suture has six lobes and six saddles, mainly bifid and slightly dissected. HAMITES sp. aff. ARMATUS Sowerby HORIZON: Base of the Pawpaw formation, clay facies. LOCALITY : 714, near Fort Worth, Texas. Fragments of a small Hamites preserved in hematite and showing on every second or third rib lour tubercles, two lateral and two ventral, are found in the basal third of the Pawpaw clay. The suture is rather similai to that of Hamites armatus Sowerby and has the following characteris- tics : Suture consists on each side of three saddles and two lobes, in ad- dition to the siphonal and antisiphonal lobes ; suture much more dissected than that of Hamites tenawa; siphonal saddle narrow and low, with three; rounded subdivisions; siphonal lobe narrow, bifid, each lobule narrow at base, trifid terminally; first lateral saddle longer and much broader than siphonal lobe, flared terminally, bifid, each division twice bifid and laterally 'In coiled ammonites the external margin of the volution (often keeled) is ventral and the internal, concealed margin is dorsal; the sides of the volution are the flanks, the terminal opening is the aperture. Lobes point backwards, away from the aperture, and saddles forwards, toward the aperture. The siphonal (external, ventral) lobe lies on the ventral mid-line and its angulated lobules point backwards; the antisiphonal lobe lies on the dorsal mid-line and its lobules point backwards. Next to the siphonal lobe and on each side of it is the first lateral saddle, and dorsal to it the first lateral lobe ; still more dorsally the second lateral saddle, then the* second lateral lobe. Further saddles and lobes are numbered seriatim and are often called adventitive elements. In straight shells (Hamites, Baculites, Ptychoceras, straight portions of Scaphites) and in fragments of Turrilites, the siphuncle should first be located; the siphonal lobe lies upon it. 70 University of Texas Bulletin dissected; first lateral lobe narrow, laterally dissected, twice bifid term- inally; second lateral saddle slightly broader, twice bifid; second lateral lobe lower, simpler, bifid, dissected laterally; third lateral saddle low, broad, rather simple, twice bifid; antisiphonal lobe very simple, rounded, slightly trifid at tip, nearly twice as tall as broad. ANCYCLOCERAS BENDIREI n. tp. PL 11, fig. 1 1920: Hamites sp. B. Winton and Adkins, Univ. Texas Bull. 1931, p. 22. MEASUREMENTS: Diameter of shell without tubercles, dorsoven- tral, at small end of fragment 19 mm., at middle of curve, 28 mm., at large end of curve 25 mm. ; same diameters, right-left, respectively, 16.5 mm., 22 mm., 24.5 mm. Number of ribs in 5 cm. along straight portion, 7; on curve, 4; average number of dorsal costellae per centimeter, 6. HORIZON: Base of Weno formation, marl facies. LOCALITY : 618 (type locality) , middle exposure, about 10 feet above the top of the Denton marl, near Fort Worth, Texas. The type, consist- ing of three fragments, and a fragment of another individual were found here. DESCRIPTION : Two limbs connected by a curve ; of these a greater part of the thicker limb and a part of the thinner limb are missing. There is not enough of the curve present to detect a spiral winding of the coil. The smaller, ascending limb increases moderately in diameter to the curve, where the fragment has its greatest thickness. There are four symmetrically placed rows of prominent, rather slender spines, two ventro-lateral and two mid-lateral. The spines of the two ventro-lateral rows are coarser and are laterally flattened at the base ; those of the mid- lateral rows are more slender and are circular at the base. These spines are widely spaced, and a set of the four spines lies on each rib. The ribs are coarse, remote, and in a plane nearly at right angles to the long axis, however, they slant ventrally towards the aperture, and dorsally from the last line of tubercles are continued as obscure elevations which cross the dorsum as narrow, fine ribs. The four rows of tubercles bound three flat longitudinal strips, one mid- ventral and two ventro-lateral; the re- mainder of the circumference is evenly curved. The cross section of the shell is therefore hexagonal in its ventral half and short oval in its dorsal half. Shell and suture are preserved. Weno and Pawpaw Formations 71 SUTURE : Similar to that of Ancycloceras lineatus Gabb1 and Hamitet quadrinodosus Jimbo.- Suture consists of medium sized siphonal lobe small antisiphonal lobe, and large, nearly equal, first and second lateral lobes and first and second lateral saddles ; the third lateral saddle is smaller. Details of siphonal lobe indistinct; the next four elements are large, slender, spreading, subequal, much dissected, primarily bifid, the subdivi- Fig. 2. Ancycloceras bendirei n. sp., suture of the type individual, camera lucida drawing, x 5. SL — Siphonal lobe; ASL — Antisiphonal lobe. sions bifid, and the resulting inflections generally minutely trifid, some- times bifid, at the tips. These four elements are subquadrate and sub- equal. The third lateral saddle is smaller, laterally dissected and twice bifid terminally. The antisiphonal lobe is about twice as tall as wide, laterally dissected, and trifid terminally, the central prolongation being the longest. This species is not closely similar to any known to me. It has some- what the form of Hamites obstrictus Jimbo, but differs in having four rows of prominent slender spines, and in the ribs, which are coarser and more widely spaced. Superficially also it resembles in form Ancycloceras matheronianum d'Orbigny (Neocomian), but differs from this species in the suture, especially in the size of the siphonal lobe and the amount of dissection of the lateral elements, in the diminished lateral ribs and in the presence of spines throughout the length of the coil instead of tubercles. HAMULINA WORTHENSIS n. .p. PI. 2, figs. 23-26 This fossil has two non-contiguous straight limbs united by a single curve, and furthermore the suture has six lobes in all, like Hamulina hamus 'Gabb, Geol. Snrv. Calif., Paleontology, vol. 2. p. 139, pi. xxiii, fig. 18c. o, Pal. Abh., vi, 3, 1894. 72 University of Texas Bulletin (Quenstedt) and H. quenstedti Uhlig.1 The juvenile portion of the shell, absent in the material at hand, may have been a close coil as in Macro- svaphites, as indicated by the grooved impression on the long limb, but this is not certain, and in addition the suture forbids identification with Macro- scaphites. The suture and the absence of ribbing prevent its reference to Ancycloceras. Bose2 describes a similar Hamulina sp. from the Vraconian limestone blocks of Camacho, Zacatecas. MEASUREMENTS : I (type) II III IV Length of fragment 7.8 mm. 10.0 8.9 8.1 Width, lower end 1.6 1.0 1.5 1.7 Width on bend 3.0 2.1 2.2 HORIZON : Base of the Pawpaw formation, clay facies. LOCALITY : 714, near Fort Worth, Texas. The type and two other individuals have been found here. Three fragments of a straight limbed ammonite, all lacking the aper- ture and part of the larger limb, were found in the basal Pawpaw clay. In the absence of better material their systematic position can not be set- tled, and I assign them with hesitation to the genus Hamulina. The curve connecting the larger limb is preserved, but this limb made no im- pression on the inner face of the smaller limb, as in some Ptychoceras, and therefore was not in close contact with it; in addition, the visible portion of the curve is open, indicating a distant, possibly short, thick limb. This might suggest Hamulina or Ancycloceras, which mostly differ in their sutures and their prominent ribbing. Whether there were three limbs as in Diptychoceras, is unknown ; however, the suture is very differ- ent from, and less dissected than that figured by Gabb for his Diptycho- ceras laevis (laeve)3 and that species also differs greatly in form from ours. Two other individuals (Plate 2, figures 23-25) show distinctly the curve and the proximal portion of the shorter, thicker limb. This is free, and is separated from the thinner limb by the space of about half of its thickness. The aperture is not visible. One individual (Plate 2, figures 23, 25) shows also a part of the curve at the lower end of the slender limb. This end turns with about the same curvature as that of the larger curve, and on the venter of the lower end of the slender limb is a wedge- iPervinquiere, fit. pal. tun., Ceph., pp. 88-89. 2B6se, On some new Cretaceous Faunas from Mexico, Univ. Texas Bull, (in p'ress). "Gabb, Pal. Cal., II, pp. 142-5, pi. xxv, fig. 21a-b. ana fa^^Kiw Formations 73 shaped groove about 1 mm. long with the shallowing, pointed end towards the aperture, which indicates that the lower end of this ammonite was a close coil, as in Ancycloceras, or a closely apposed limb. These three individuals agree essentially in their sutures. DESCRIPTION: Only fragments preserved, showing a small limb, the curve connecting with the larger limb, and a portion of this limb. Suture present ; shell, aperture and lower portion of slender limb absent. The curve, in the type individual does not quite turn to a position parallel to the small limb; and the two limbs are not in contact, at least at the curve. Dorsal side with a central and two lateral flattened smooth strips (the antisiphonal lobe lies on the former), making the cross-section near the turn a very thick crescentic or kidney bean shape, slightly concave dorsally and broadly convex ventrally. The smaller limb is slender in its younger stages and thicker to a point near the curve; here there is a slight dorsal inflation beyond which are no sutures; farther up, at the curve, there is a slight dorsal constriction. The ventral mid-line bears a small ridge which apparently marks the siphuncle. SUTURE : The suture is but slightly dissected, and consists of two Fig. 3. Hamulina worthensis n. sp., Sutures of type individual, camera lucida drawing, x 16. lateral lobes and three saddles, in addition to the siphonal and1 anti- siphonal lobes. The siphonal lobe is bifid and has two slender elongate tips ; it is about twice as tall as broad. The first and second lateral saddles are nearly equal and similar; each is about half as tall as broad, and is bifid by a shallow, simple lobule. The first lateral lobe is trifid and pro- gressively diminishes in size from the younger to the older sutures. The second lateral lobe is rather smaller than the first, and is bifid. The third lateral saddle is of the same height and about half the width of the other two, and is broadly rounded and unequally bifurcated by an angular notch 74 University of Texas Bulletin lying nearer the antisiphonal lobe and making the more dorsal division smaller than the more lateral one. The antisiphonal lobe is peculiarly narrow and elongated, and has a slightly inflated, bifid tip. The suture has the same number of elements, six lobes and six saddles, as Ptychoceras, and the species seems to have some resemblance to P. laeve, var. hamaimensis Pervinquiere1 (Lower Gault, Tunis) ; however, the first two saddles of our species are broader and less dissected; the third saddle is unequally and shallowly bifid ; the first lateral lobe is trifid instead of bifid ; and the other lobes are bifid. The African species also differs greatly in form from ours, in having two apposed limbs and annular constriction and inflations on the thicker limb. The Texas Upper Cretaceous (Navarro) species Ptychoceras texanum (Shumard)2 has the two limbs strongly ribbed and closely apposed. BACULITES COMANCHENSIS n. sp. PI. 2, figs. 20-22 1920: Baculites sp., Winton and Adkins, Univ. Texas Bull. 1931, pp. 21, 69. MEASUREMENTS : I (type) II III Length 12.5 17.3 13.4 Smaller end, major diameter 3.3 4.0 3.9 Smaller end, minor diameter 2.9 3.4 3.0 Number of ribs in 5 mm 5 1-2 Larger end, major diameter 6.1 Larger end, minor diameter 3.4 3.7 3.1 Number of ribs in 5 mm 4 1-2 3 A characteristic Pawpaw baculite lacking the aperture and the coiled portion, will be described here on account of its stratigraphic importance. The straight portion is preserved with the sutures, as a limonite cast. HORIZON : Pawpaw formation, clay facies, base, rare. LOCALITIES: Individual II from locality 714, near Fort Worth, Texas; type individual (PL 2, fig. 21) and the others from locality 719, west — facing hill to east of Crowley road, one! mile south of the Baptist Seminary, four and a half miles south of Fort Worth, Texas. DESCRIPTION: Straight fragments preserved, slightly and uni- formally tapering, lateral outlines slightly undulating but on the whole straight; cross-section a short oval; living chamber not preserved, but 'Et. pal. tun., p. 90, pi. IV, figs. 5, 6a-b. c. Bost. Soc. Nat. Hist., 8, 1861 (1862), p. 190. Weno and Pawpaw Formations 75 sutures suddenly more crowded at larger end. Ribs consist of evenly rounded, low, annular swellings in a plane nearly perpendicular to the long axis of the shell, more crowded near the enlarged end, almost equally steep on both sides of the annulation, tallest on the venter and on the ventral half of the sides, thence decreasing in height toward the dorsum, where they turn sharply toward the more constricted end of the shell and become obsolete upon crossing the dorsum. Over the more constricted lower end of the shell a suture lies in the lower half of the valley between each two annulations, but in the thicker part of the shell the relation of sutures to annulations is variable; near the thicker end in the type, the sutures are crowded. SUTURE: Besides the siphonal and antisiphonal lobes, the sutural elements consist of three lateral saddles and two lateral lobes. The Fig. 4. Baculites comanchensis n. sp., sutures of type individual, camera lucida draw- ing, x 8. siphonal lobe is bifid, having two slender, rather acute points and a rela- tively broad, low, crenulate, external saddle; this lobe is nearly twice as tall as broad. The antisiphonal lobe is extremely small and simple; it consists of a single long, narrow, rounded point. The first lateral saddle is about twice as wide as the siphonal lobe and is deeply bifid by a rather simple lobule with one central and two incipient lateral points; each of these portions is again bifid. The first lateral lobe is very tall and bi- furcated terminally.1 The second saddle is bifid and not quite as wide as the first; of its divisions the ventral one is trifid and the dorsal one bifid. The second lobe is broader at the base than the first, and about two-thirds the height; it is bifid terminally. The third saddle is broadly rounded and shallowly bifid. The suture (Fig. 5) is peculiarly simplified and is very characteristic. It is somewhat similar to that of Baculitef, vertebralis Lamarck (Santonian), but differs in having a very simple and reduced antisiphonal lobe and third lateral saddle, and in the greater breadth and simplicity of its first and second saddles. It has even less resemblance to Baculites baculoides Mantell (Vraconian), whose saddle? 'If the lobes are trifid the fossil belongs to Bochianites Lory; however, the suture agrees better with Baculites. 7li University of Texas Bulletin and lobes are narrow, much dissected and constricted basally. I have not had opportunity to compare this species with other Vraconian and Albiar, species. TURRILITES BOSQUENSIS n. sp. PL 3, figs. 3, 7 MEASUREMENTS : Height of spire 21 mm. Diameter of last volution . 12 mm. Aperture, height 7.2 mm. Aperture, breadth 6.1 mm. HORIZON: Middle of Del Rio clay at top of abundant horizon of Exogyra arietina Roemer, in association with Flickia 1 bosquensis Adkins, Acanthoceras worthense Adkins, Pecten subalpinus (Bose), Gryphea mucronata Gabb, and small pyrite fossils. The turrilite apparently is abundant. LOCALITY : West bank of the South Bosque River, 150 yards south of the bridge on the Speegleville road, tall Del Rio cliff, 5.5 miles west of the courthouse at Waco, Texas (type locality) . DESCRIPTION: Shell conical, sharp spired, spiral angle 37 degrees near tip but spreading slightly on the last volution, sinistral, turreted, five volutions in the type, decreasing rapidly in size towards the apex. In side view the volutions are more angulated and the tubercles relatively more prominent than in any other known Texas turrilite. There are four spiral rows of tubercles, of which three are large and nearly equal and lie on the prominent flank of the volution and the fourth is diminu- tive and lies beneath the upper margin of the volution. The third row of tubercles lies at the exact margin between the volutions and is there- fore covered as is the fourth small row, by the succeeding volution, so that on the earlier volutions only two rows of tubercles are exposed. Of these the lower row, nearest the siphuncle, is separated from the lower ex- posed margin of the volution by a broad smooth evenly curved spiral strip. Tubercles of the first and second rows1 are obliquely placed and are not connected by visible ridges. The third row is closely spaced, the tubercles being more numerous than in the first two rows, and this row 1Counting from below when the turrilite is placed point down (See Pervinquiere, Et. pal. tun., Ceph., p. 428). The siphuncle is then inferior and may be concealed by overlap of the next volution. Weno and Pawpaw Formations 77 is separated from the second row by a sharply excavated spiral groove of only half the width of the space separating the first two rows. Finally, the small tubercles of the fourth row are paired with the tubercles of the third row, the tubercles of a pair being connected by an obsolete radial ridge. The angularity of the volutions is caused by the lateral projection of the first and second rows of tubercles. In the type individual, the sec- tion of the last volution (pi. 3, fig. 7) is elliptical in its basal (dorsal) half, and the inner margin is evenly rounded. The superolateral margin is incised between the three prominent tubercles, and the superior margin in the region of the fourth line of small tubercles is almost straight. SUTURE: The type individual shows a series of suture stages be- ginning on the earliest preserved volution. This volution is rounded and I .•»*•• o/ Q 1 o20, °* Fig. 5. Turrilites bosquensis n. sp., sutures of type individual, camera lucida draw- ing, x 8. The numbers indicate the volutions on which the corresponding sutures occur. is totally smooth and tubercles begin to appear only at a diameter of spiral of 2.8 mm. At this point the volution is 1.1 mm. thick and the first and second rows of tubercles appear simultaneously. The suture is simple and consists of a low, undissected siphonal lobe, a simple first lateral saddle, a slightly smaHer and still undissected first lateral lobe, a slightly bifid but otherwise simple second saddle, and an undivided 78 University of Texas Bulletin second lateral lobe, of which half is concealed by the next volution. The siphonal lobe of the second volution is dissected, and the two lateral sad- dles are bifid with simple rounded subdivisions, but the lateral lobes are rounded and undivided. On the third volution the saddles become still more complicated, in general being trifid, but the lateral lobes have little inflection. The siphonal lobe has elongated to its final form but still lacks secondary inflections. In the fourth volution the siphonal lobe is subdivided laterally, and has mature inflections and form. The lateral lobes are slender and trifid, and the lateral saddles are dissected, in general twice trifid. The final volution of the type individual has all elements of the suture dissected (the siphonal lobe was poorly preserved and likely is more dissected than is shown in the drawing) . The first saddle is twice as broad as the first lobe and is broadly bifid. The second saddle is bifid and the second lobe in this individual indeterminate. Number of individuals: about 10. TURRILITES WORTHENSIS Adkins and Winton PI. 3, figs. 1, 6 This common Pawpaw species marks the clay phase in the region from Denton to Johnson County, Texas. It is more abundant in the basal five feet of the formation. The species is rare in the marl transition phase, one individual having been found near Riovista. The species is very rare or missing in the Red River region. TURRILITES sp. PI. 3, figs. 2, 4 There are several dextral and sinistral turrilites, preserved in hematite or pyrite, which characterize the Pawpaw clay, and material is being collected for a further study of their structure. In numbers these tur- rilites are abundant and are one of the most striking features of the fauna. They likewise are rare except in the clay facies, and have not been found so far, north of Denton County or south of Johnson County, Texas. Turrilites similar to these species have been found in the Del Rio clay just above the Exogyra arietina horizon (equivalent of Grayson formation) near Waco and Austin, Texas. Weno and Pawpaw Formations 79 SCAPHITES HILLI Adkins and Winton PI. 2, figs. 1-12 1920: Scaphites hilli Adkins and Winton, Univ Texas Bull. 1945, p. 37, pi. 7, figs. 3-6. 1920: Scaphites hilli Winton and Adkins, Univ. Texas Bull. 1931, p. 21. 1920: Scaphites sp. A. Winton and Adkins, ibid., pp. 21, 69. I II III IV V VI PI. 2, PI. 2, PI. 2, PI. 2, PI. 2, PI. 2, Fig. 1 Fig. 4 Fig. 7 Fig. 8 Fig. 12 Fig. 17 MEASUREMENTS Greatest length 9.6 9.5 13.5 11.0 8.0 7.5 Greatest thickness 8.2 4.4 7.3 4.8 7.0 6.5 Diameter of coil 7.8 3.8 6.0 6.5 7.0 6.2 Length of uncoiled portion .... 5.0 8.0 7.5 .... ...: Thickness of last turn 8.2 4.4 4.5 2.6 2.6 3.6 Thickness of next to last turn 3.6 3.1 1.5- Greatest length of umbilicus 1.8 1.2 2.1 2.0 1.6 1.2 Number of (ventral) ribs per centimeter, on coil 20 28 20 26 32 26 On uncoiled portion 24 26 .30 HORIZON: Basal half of Pawpaw formation, clay phase. This species has so far not been found outside of Tarrant County, Texas, but it may be expected throughout the extent of the clay phase of the Pawpaw, or farther. LOCALITY: Most frequent at the type locality one-fourth mile south of the International and Great Northern Railway bridge across Sycamore Creek, Fort Worth, Texas (locality 714), and one-half mile west of the Glen Garden Country Club, Fort Worth, Texas (locality 723). NUMBER OF INDIVIDUALS : About 25 individuals have been found. These are in the Bureau of Economic Geology, Austin, Texas, and Texas Christian University, Fort Worth, Texas. TYPE INDIVIDUAL: From locality 714 (described above) : deposited in Walker Museum, Chicago. MODE OF PRESERVATION: Type, dark reddish brown hematite; other individuals light reddish yellow limonite; a few scattered pyrite cubes noted. DESCRIPTION: This scaphite consists of a coiled portion and an elongate unrolled portion terminating in the aperture, and at their junc- tion there is a prominent dorso-lateral tubercle or geniculation which may be taken as an orienting point in describing the ribs and sutures of this fossil. 80 University of Texas Bulletin The coiled portion consists of an unknown number (3 or 4 ?) volutions, and the umbilicus is deep and, due to the position of the dorso-lateral tubercle, has a kidney-bean shape with the end nearer the aperture some- what pointed. There is a distinct elongation, which in the absence of the uncoiled portion will orient the shell. For the most part there are no sutures nearer the aperture than the dorso-lateral tubercle, and the uncoiled portion represents the living chamber, and therefore lacks sutures. Coiled portion ventricose to subglobular, very obese, subovate in out- line, evenly and almost circularly rounded ventrally ; dorsally the circular margin is broken by the incurved margin of the dorso-lateral tubercle, resulting in a more or less open crescentic or tear-shaped umbilicus, lying slightly oblique to the axis of the uncoiled portion; greatest transverse diameter of coil ventral to this tubercle; coil slightly constricted just above the tubercle. The uncoiled portion of which the part below the tubercle is the living chamber, is elongate and ornamented with numerous fine ribs which course obliquely from the dorso-lateral margins to the venter, being nearer the aperture at the latter point. The living chamber is in- flated at the edges at the dorso-lateral tubercle where it is in contact, with the coil, constricted dorsally at a point a little nearer the aperture and thereafter on approaching the aperture is constricted and curved dorsally. Its dorsal side is excavated into a prominent groove, whose width is about half that of the living chamber, and into which the coil fits at the upper end; the groove thus is exposed from the coil to the aperture. The resulting cross section of the living chamber is concave- convex, the short dorsal concave margin passing over the sharply rounded edges of the dorsal groove into the longer lateral and ventral margin. This section varies at different points of the scaphite; near the aperture it is more concave dorsally. FORM : There is a variation in form, amount of embracing and rate of increase in size of the successive volutions, as is seen also in the inter- grades between Scaphites obliquus and Scaphites aequalis.1 The type of Scaphites hilli is an obese individual with thick, rapidly expanding volutions, which closely approaches the typical S. aequalis Sowerby as figured by Pervinquiere. This expansion over the last volu- tion of the coil amounts to a doubling of the breadth of the coil, the breadths at the dorso-lateral tubercle and at the point opposite it on the next volution being in the ratio of 8:3.6 in the type. The amount of thickening interiorly is also great, since the umbilicus is deep. The re- 'Pervinquiere, Et Pal. Tun., pp. 118-120. Weno and Pawpaw Formations 81 suiting cross-section of the last turn is thickly crescentic (pi. 2, fig. 1). The remaining individuals have thick coils but show a less rapid ex- pansion of the last volution. One individual (pi. 2, fig. 7) has preserved most of the uncoiled portion which is a thick crescent with rounded sides and a relatively narrow non-ornamented dorsal groove; the aperture is destroyed. Usually only the coiled portion is preserved, and these in- dividuals are of variable size, even when the dorso-lateral tubercle is also present. They have the same relative thickness and expansion of the coil as the individuals of S. aequalis figured by Pervinquiere.1 It is notable that the ribbing becomes obsolete over the lower half of the dorso-lateral tubercle and the entire apertural region. A straight groove of variable prominence along the ventral midline is a feature of all material found. RIBS : The ribs are branched or unbranched. They are most numer- ous at the ventral mid-line and thence laterally some stop short of the dorso-lateral margin and some pass over this margin with a pronounced sigmoidal flexure and describe across the dorsum an arcuate curve, con- vexed towards the aperture. These principal ribs are thick and elevated laterally. In addition there are shorter ribs which are best developed at the venter and disappear at both ends, or else branch from a principal rib laterally, and crossing the venter disappear laterally, on the opposite side of the coil. There is some irregularity in the distribution of these types of ribs, as follows: In one invividual (pi. 2, fig. 7) in the region at the end of the uncoiled portion there are long and short simple ribs and branched ribs but the long simple ribs predominate. In the branched ribs the point of branching is far ventral, lying one-third the distance from the ventral midline to the dorsal midline. Near the dorso-lateral tubercle there are long and short simple ribs with rare incipient branching; the short ribs decrease in length, as their ends lie farther from the umbilicus. The same statements hold for the other individuals figured. In the distal half of the outer volution of the coiled portion a short simple rib alter- nates with a -long simple rib ; however, there is incipient branching in the long ribs opposite the dorso-lateral tubercle (pi. 2, fig. 7) sporadically near the tubercle (pi. 2, fig. 4) or even over the whole distal half of the volution (pi. 2, fig. 12). In one individual (pi. 2, fig. 8) there are alter- nate long and short simple ribs next to the tubercle, but more proximally, there is an irregular alternation of simple and branched ribs. In general, this region shows an alternation of long simple ribs with short simple, ones, and incipient or developed branching. This is the situation in the 'Et. Pal. Tun., plate IV, figures 24-26. 82 University of Texas Bulletin type individual (pi. 2, fig. 1) in which the ribs are at some places evi- dently branching, and at other places apparently of alternate length. The remaining visible portion of the coil shows in general an alter- nation of one branched with one unbranched rib. This alternation is often irregular ; in pi. 2, fig. 8 the simple ribs preponderate. The branch- Jng may be incipient giving the impression of an alternation of one branched rib with two simple ribs or of one long simple rib alternating with two short simple ribs (pi. 2, fig. 12) . In one individual (pi. 2, fig. 12) a branch from a principal rib at one umbilical margin crosses the venter and fuses with the next principal rib, giving a zig-zag ribbing. Briefly the ribbing is more branched on the coil and simpler' on the straight portion. It is seen that the ornamentation of the coil somewhat resembles that of S. meslei Grossouvre (Coniacian), which, however, has the principal ribs more prominent and the secondary ribs largely un- branched; this species also unrolls much less rapidly than the type of S. hilli. The obesity of the typical S. hilli also removes it from S. obliquus as does the coarseness of its ribbing; in fact, no individual known ap- proaches S. obliquiis in either respect. In both respects it is similar to the thick coiled examples of S. aequulis Sowerby, from which it differs in the rate of increase of its turns, in the dorso-lateral tubercle and shape of the umbilicus, and in the suture. S. aequalis shows the same prom- inence of the primary ribs near the umbilical margin and the same branch- ing laterally on the coil, as S. hilli. Fig. 6. Scaphites hilli Adkins and Winton, suture, type individual, camera lucida drawing, x 12. The fossil is figured on PI. 2, fig. 1. SUTURE: Figure 6 shows the suture of the type, so far as can be seen without dismembering the scaphite. This well developed suture has externally besides the siphonal lobe, two conspicuous lobes and near the umbilical wall a third irregular, low, wide lobe. Of these, the first lateral Weno and Pawpaw Formations 83 lobe is narrow, very tall, and trifid, with the central point strongly de- veloped. The second lateral lobe is broad, nearly the same height as the siphonal lobe, its breadth being about six tenths that of the first saddle, and is bifid with each lobule split into rounded tips. The third lobe is twice as broad as tall and is obscurely split into four rounded divisions. The first saddle is large, subquadrate in outline and deeply bifid; each division is split by a lobule into two unequal bifid components. The second saddle is bifid. The third saddle, which lies on the umbilical wall, is wide and low. Fig. 7. Scaphites hilli Adkins and Winton, young individual, showing the last five sutures, camera lucida drawing, x 10. The fossil is figured on PL 2, figs. 3-4. A comparison of the mature suture of the type with juvenile suture stages is represented in figure 7. This individual differs from the type in many ways ; it is less obese and its coils increase less rapidly ; its rib- bing is possibly coarser; its first lateral saddle is shallow and very wide and is split by a shallow lobule, whereas it is tall, narrow and split by a deep lobule in the type of S. hilli; the two have the same horizon and range and are apparently connected by intergrades. The situation is somewhat similar to that of Scaphites aequalis and S. obliquus, and until further material is available, I would refer this form to S. hitti. This suture is seen to be simpler and to lack the finer divisions of saddles and lobes seen in figure 6. The lobes on both individuals are, however, bifid. 84 University of Texas Bulletin The internal suture of a small individual whose form and ribbing mainly agree with the last named individual is shown in figure 8. This suture has six lateral and internal saddles and five lobes. The anti-siphonal lobe is trifid, the remaining ones bifid. AT^ Fig. 8. Scaphites hilli Adkins and Winton, external and internal suture, camera lucida drawing, x 10. Very closely related to this species is Scaphites worthensis Adkins and Winton (Duck Creek marl) which, however, lacks the ventro-lateral tu- bercle; its suture also differs in several respects. Scaphites semicostatus Roemer and S. texanus Roemer, have been described from the Eagleford formation near New Braunfels; S. vermiculus Shumard from the Eagle- ford near Woodlake, Grayson County; and S. vermicosus Shumard from the Navarro near Dresden, Navarro County. ENGONOCERAS SERPENTINUM (Cragin) PI. 4, figs. 3, 5-6, 12 1900: Sphenodiscus belviderensis, var. serpentinus Cragin, Colo. Coll. Stud., viii, p. 31, pi. 2, figs. 4-6. 1903: Engonoceras serpentinum Hyatt, U. S. G. S., Mon. XLIV, p. 162, pi. XIX, figs. 7-14; pi. XX, figs. 1-5. 1918: Engonoceras serpentinum Stephenson, U. S. G. S., Prof. Paper 120-H, p. 143. This distinctive Engonoceras is frequent in the shales of the Middle Weno formation in Grayson and Cooke counties, Texas. Shell nacreous in the material studied, with fine, close, sigmoid, radial striae; suture simple, as figured by Hyatt (U. S. G. S., Mon. XLIV, pi. XIX, fig. 7) ; venter rather square, angulated and rounded at edges, zigzag due to alternating marginal tubercles on the two flanks. HORIZON: Lower and Middle Weno shale and ironstone; Pawpaw shale. LOCALITIES : Frisco cut, three-fourths mile north of Union Station, Denison, Texas, and the cut of Duck Creek just west of this locality; pit of brickyard, one and three-fourths miles southeast of Gainesville, Texas ; Pawpaw bluff on the Red River, northwest of Cedar Mills, Texas. Weno and Pawpaw Formations 85 ENGONOCERAS sp. PI. 4, figs. 8-10 The most numerous fossil in the basal Pawpaw clay is Engonoceras; this genus is rare in the Duck Creek, Denton, Grayson, and Del Rio pyrite faunae, and its abundance is diagnostic for the Pawpaw clay as so far examined. There is probably more than one species in this formation. The individuals are small (one inch or less), hematitic or pyritic, with sharply etched sutures; flanks smooth and nearly flat; venter straight- edged, angulated, concaved on the midline (so far as observed never acute as in Metengonoceras) ; umbilicus narrow; sutures of varying complexity, mainly very simple, with numerous auxiliary elements. HORIZON: Pawpaw formation, clay facies, abundant: Tarrant County, numerous localities; Denton County, Johnson County. Grayson formation : marl facies and middle clay member, rare, Tarrant and Denton counties. Denton clay : rare, Denison to Blue Mound, north of Fort Worth. Duck Creek marl: rare, Grayson to Tarrant counties. FLICKIA BOESEI n. sp. PI. 1, figs. 1-3 1920: Flickia sp. Winton and Adkins, Univ. Texas Bull. 1931, p. 69. HORIZON : Pawpaw formation, clay facies, base. LOCALITY : Type individual, base of Pawpaw formation, just or top of Weno limestone escarpment, one-fourth mile east of Riovista-Waco road and one mile south of Riovista, Texas. One eroded individual, the type, was found here. MEASUREMENTS : Height of last whorl, 3.5 mm., width, 4.6 mm. ; greatest diameter, 10.5 mm ; width of umbilicus, 3.7 mm. DESCRIPTION: Form discoidal, inflated, volutions thick, with thick, crescentic section, moderately embracing, umbilicus deep, open, showing at least five volutions. Cast smooth and unornamented. From the section of the end of the coil it is evident that the volution at this age embraces only about half of the preceding one; the volutions are also much broader and lower than in the adult Flickia simplex, having at the end of the fifth (?) volution a ratio of breadth to height of 3:2. The flank is broadly convex and passes into the umbilical wall by a sharp 86 University of Texas Bulletin convexity of more than a right angle. The curvature of the venter is nearly elliptical ; a keel is lacking, but at the ventral midline of the latest part of the coil there is a perceptible rounded angulation. The dorsal region of the last volution has a more nearly circular curvature than the venter, and the venter of the next younger volution is therefore taller and more nearly circular than the outer volution. SUTURE : Goniatitic, as in Flickia simplex Pervinquiere, from which it differs only in minor details. All of the sutural elements are less tall and relatively less slender than in the African species. As in that species there are three lateral saddles and three lateral lobes; of these the first and second lateral saddles and most of the second lateral lobe lie upon the flank, while the remainder of the visible suture lies On the steep umbilical wall. The siphonal lobe is bifid with two low, rounded points and a cen- tral (external) saddle; the saddle has a greater breadth and is considerably less pointed than the lobules, in fact it has a very broad, even, arcuate curvature. The first lateral saddle is broad, non-angulate, evenly curved and almost as tall as broad; its breadth occupies nearly half that of the flank. The first lateral lobe and the second lateral saddle have almost the same size and shape: each is rounded terminally, having almost a circular curvature, and slightly more constricted basally; and the second lateral saddle has in one instance a very slight suggestion of angularity, like Neolobites. The second lateral lobe and the third lateral saddle are low, broad and non-angular. The foregoing description is from the type individual. Fig. 9. Flickia boesei n. sp., type individual, sutures, camera lucida drawing, x 8. Pervinquiere1 established the genus and species Flickia simplex to in- clude a small ammonite with simplified suture remotely like Neolobites, from the Vraconnian of Tunis. Comparing the latest sutures of the two types,2 ' we find that the first lateral saddle of the Texas species is somewhat lower and broader than that of Flickia simplex; the second one is higher and lies entirely upon the flank, while in the African species it appears to lie partly upon the umbilical wall; the external saddle of Pervinquiere: Et. pal. tun., p. 212, pi. 9, figs. 2-5, text figs. 80, 82. Weno and Pawpaw Formations 87 Flickia boesei is lower and more flattened than that of F. simplex; and the siphonal lobe is narrower and taller and instead of being inflated,1 tapers slightly to the end. The Texas type is probably juvenile, since the living chamber is lacking, and since it is more similar to the younger than to the older sutures of Flickia simplex. Such simplified ammonites afford few visible characters for comparison, and therefore separations must be*made on the basis of slight superficial differences. Very likely better preserved material will afford a more secure basis for distinguishing the species and for defining its relation- ships. Provisionally it is placed in Flickia on account of its form ana suture. Since the species differs only slightly in form, cross-section and suture from Flickia simplex, essentially the same arguments as to its gen- eric position hold. It is notable, however, that in the Texas species the resemblance to Neolobites suggested by Pefvinquiere is even more striking than in Flickia simplex, especially in the very slight angularity of the saddles. FLICKIA (?) BOSQUENSIS n. sp. PI. 1, fig. 4; PI. 4, fig. 11 There has recently come to light a peculiar Flickia-like ammonite, which although not belonging to this genus as described by Pervinquiere seems to stand closer to it than to any other genus, and is here described on account of the possible light that it may throw on the relations of this obscure group. This ammonite has prominent umbilical tubercles and a few widely spaced low, rounded, coarse ribs, and the marginal tubercles are lacking. In these respects it agrees with Neolobites, but is thicker, more discoidal, has a more rounded keel, a more open umbilicus, and the suture consists of three saddles and two lobes, the first saddle being much taller and broader than the second. It will be seen that the suture has fewer elements than in Neolobites, and in this respect is like Flickia. The suture resembles that of Flickia in the simplicity, the roundness and the non-angularity of its elements; it differs in having the siphonal lobe broader and its sides more convergent towards the tip, the first lateral lobe shorter than the siphonal lobe, and the first lateral saddle much broader than the siphonal lobe. It differs from Flickia simplex and F. boesei in having ribs and umbilical tubercles instead of being smooth. The sutures on this ammonite are more numerous and crowded than in either genus mentioned. Due to lack of literature, a more exact generic determination can not be given. 1Ibid., Pervinquiere, p. 214, figx 82. 88 University of Texas Bulletin HORIZON: Top of lower half of the Del Rio clay, equivalent of Gray- son formation (top of zone of Exogyra arietina, in association with Turrilites bosquensis, Acanthoceras worthense, Pecten subalpinus, Gryphea mucronata) . TYPE LOCALITY : West bank of the South Bosque River, 150 yards south of the bridge on the Speeglevilte road, tall Del Rio cliff; 5.5 miles west of courthouse at Waco, Texas. DESCRIPTION : Form inflated, section of volution rather tall, flanks and venter broadly rounded, keel absent, dorsum concave with a sharper curvature than the venter ; volution covering about one-third of preceding one. Volutions with few widely spaced, very large, smooth, low umbil- ical tubercles each one-third to one-half the height of the volution; from each of these a single low broad rib runs ventrally, reducing in height and disappearing at the ventro-lateral margin. Ventral marginal tubercles absent. Umbilicus wide. Only three volutions visible in the type (in- terior damaged). The form is approximately that of Flickia boesei ex- cept for the presence of ribs and the much more open umbilicus. In the type the crowded sutures end abruptly near the end of the last volution, beyond, which the living chamber has several oblique low ribs each term- inating in a low, indistinct umbilical tubercle. SUTURE: In form the suture is rather like that of Flickia or of Neolobites, with a slight angularity in some places. Three lobes and three saddles visible on each side, including the siphonal lobe. Siphonal lobe Fig. 10. Flickia (?) bosquensis n. sp., diagrammatic projection of sutures of type individual, camera lucida drawing, x 5. subquadrate in outline, with two equal, simple, rounded lobules and a shallow external saddle. First lateral saddle about one and two-thirds times as broad as the siphonal lobe, more angular on its ventral margin, more evenly curved dorsally. First lateral lobe about half as broad as Weno and Pawpaw Formations 89 first saddle, lower than first saddle or siphonal lobe. Second saddle still lower, about one and a half times as tall as the first lobe. Second lobe nearly as broad as second saddle, and somewhat lower. Most of third saddle visible externally, lying entirely on steep umbilical wall. Further elements of suture concealed by overlap on next inner volution. All su- tural elements are simple and entire, as in Flickia. SCHLOENBACHIA WENOENSIS n. sp. PI. 1, fig. 14 MEASUREMENTS: (Type individual). Height of volution, 8.0 mm. Width of volution, 4.7 mm. HORIZON : Base of Pawpaw formation, clay phase. LOCALITY : 723 (type locality) ; 714, both on Sycamore Creek, near Fort Worth, Texas. The species is rather rare; only a few fragments, most of them crushed, have been found. The genus Schloenbachia Neumayr, in the restricted sense adopted by de Grossouvre, Pervinquiere and others, includes ammonites with sinuous simple or branched ribs, umbilical and marginal tubercles, and sutures with the first lateral lobe usually trifid. Mortoniceras on the contrary usually has a square cross-section, coarse, almost straight, tuberculate ribs and the suture less dissected than in Schloenbachia, with the first lateral lobe more or less square and bifid. The type species are Mortoniceras texanum (Roemer) and Schloenbachia varians (Mantell). A rather rare pyritic species of the Pawpaw clay is here described on account of its stratigraphic importance. DESCRIPTION: Form discoidal, volutions rather flat and broad moderately embracing, outer volution covering about one-third the width of the preceding one, umbilicus therefore wide and open and, on account of the flatness of the volutions, rather shallow; three coils only exposed in the type (fragment), the two inner ones being practically smooth, the outer one decorated with numerous, closely spaced, low, evenly rounded, sigmoidal, branched and simple ribs, most of them having distinct, sharply elevated umbilical tubercles, which are nearly of even height and evenly spaced around the inner margin of the volution ; and near the ventral margin a low overturned, sharp-topped, oblique ridge representing the twin marginal tubercles. On this ridge the more dorsally situated tubercle is represented by a gently curved elevation and the more ventral tubercle is sharper-topped and descends abruptly by a steep ridge and becomes 90 University of Texas Bulletin obsolete at a point near the keel, leaving practically no groove bordering the keel. The ribs, on this ridge, have sigmoidal flexures directed for- wards, while at the umbilical margin the ribs are directed backwards. The keel is sharp-topped, triangular in section, and elevated above the level of the lateral tubercles. The section of the volution is rectangular and slightly broader dorsally. At the widest point on the volution its height and breadth are in the ratio of 3 :2. The section is thus truncate- cuneiform; the flanks are practically straight, the venter lightly arcuate, and the dorsum has a V-shaped excavation for the reception of the next inner volution. SCHLOENBACHIA WINTONI n. sp. PI. 3, figs. 8-11 1920: Sehloenbachia sp. M, Adkins and Winton, Univ. Texas Bull. 1945, p. 34, pi. 5, figs. 1-4. 1920: Sehloenbachia sp. M, Winton and Adkins, Univ. Texas Bull. 1931, p. 22. MEASUREMENTS : ( Type individual ) . Greatest height of last volution 34 mm. Greatest breadth of last volution, excluding tubercles 32 mm. Greatest diameter of shell . 104 mm. HORIZON: Upper Weno formation, shale and limestone facies, and ironstone bands in the blue shale of the Red River region. Known also from south-central Texas. LOCALITIES: 601, clay-ironstone layers in blue shale of upper part of Weno formation, pit of brickyards, one and three-fourths miles south- east of Gainesville, Texas (type locality) ; 604, cut of Frisco track, three- fourth mile north of Union Station, Denison, Texas; 612, 618, 714, 715, 716, near Fort Worth, Texas ; 720, 721, near Riovista, Texas. DESCRIPTION: Shell discoidal, volutions thickened, umbilical wall steep, passing onto the flank by a rounded curve. Venter truncate, keel low with a parallel groove on each side. Flanks slightly convex between the ribs. Cross-section of volution subquadrate, slightly wider dorsally than ventrally. Flanks ornamented with ribs, each connected with a ven- tro-marginal tubercle. These ribs are either simple or bifid. The simple ribs disappear dorsally before reaching the umbilical angle. The bifid ribs end dorsally in a single, very tall umbilical tubercle and ventrally in two less elevated marginal tubercles. Visible portion of suture consists of siphonal lobe, two lateral saddles Weno and Pawpaw Formations 91 and two lateral lobes. The siphonal lobe is about twice as tall as broad, and laterally is minutely dissected, and has also two or three prominent lateral inflections. The terminal points are slender and slightly incised laterally. The first lateral saddle is nearly twice as broad as the siphonal lobe and is trifid, having the more dorsal division slightly dissected, the broader central division trifid, and the slender ventral division next to the siphonal lobe entire. The deepest incision in the saddle lies between the first two divisions. The first lateral lobe is slender and about two and Fig. 11. Schloenbachia, wintoni n. sp., type individual, last suture, camera lucida draw- ing, x 5. Keel region slightly distorted in type individual. one-half times as tall as broad. It is bifid terminally and the ventral lobule is larger. Each lobule is trifid. The selond saddle is lower and broader than the first lobe, and is bifid terminally; laterally it has an ir- regular outline. The second lobe is broad and bifid. The internal suture has not been examined. This species differs from Schloenbachia nodosa Bose and S. trinodosa Bose in its suture and in the cross-section of the volution ; it differs from the common Schloenbachia of the Fort Worth limestone (S. leonensis of various authors) in many respects, notably in its marginal tubercles. MORTONICERAS WORTHENSE n. sp. PI. 1, figs. 6-10, 18-19, 26 1920: Mortoniceras sp. Winton and Adkins, Univ. Texas Bull. 1931, p. 68. MEASUREMENTS: I (tpe) II III IV Fragment, outer whorl ; length 15.0 16.5 14.4 10.8 Small end, height 3.5 4.3 3.0 2.4 92 University of Texas Bulletin Small end, width 4.0 4.0 4.0 3.1 Large end, height 4.5 5.5 5.3 4.0 Large end, width 4.3 4.8 4.7 3.6 HORIZON: Basal two-thirds of the Pawpaw formation, clay phase. LOCALITY : 723 (type locality) ; 714, and other localities near Fort Worth, Texas. DESCRIPTION: Shell discoidal, volutions slightly embracing, each covering one-fourth or less of the next inner volution, umbilicus conse- quently broad, volutions strongly ribbed with widely spaced, coarse, short, simple or bifurcated, straight ribs, each with an umbilical tubercle and a pair of coarse marginal tubercles which are connected by a concave topped ridge. These tubercles are abruptly raised above the level of the venter, but the oblique rapidly diminishing rib passes from the tubercle towards the keel and becomes obsolete; the keel is therefore bounded on each side by a narrow valley. Keel prominent, steep sided, triangular in section, taller than the outer ventro-lateral tubercle in the earlier volutions, lower in the later ones. Cross-section of the volutions roughly square, but in a few individuals even broader1 than tall ; to be more detailed, the flanks are inflated, and in the region of a rib bicarinate, corresponding to the umbilical and lateral tubercles; venter tricarinate, corresponding to the keel and the two ventro-lateral tubercles; dorsal midline with a slight excavation, into which the next inner coil fits. Number of volutions six or more. At the 6 mm: stage (about four volutions) the shell is prac- tically without ribs. The ribs then come in as straight, broad, low, wedge- shaped elevations, thicker and higher at the marginal end, where the pair of marginal tubercles is an elongate prominence with a slight tuber- culate swelling at each end. Within the next half volution the umbilical tubercles have become prominent, and the marginal tubercles are as tall as the keel, giving to the cross-section of the volution a nearly square aspect, instead of the triangular section which exists in the younger stages, in which the keel is still prominent. The sutures coincidently increase in complexity. SUTURE : The siphonal lobe is nearly quadrate. It is bifid and each lobule is relatively simple. The first saddle is broad and is twice bifid. The remainder of the suture is invisible on the flanks of the individuals at hand, which are preserved as pseudomorphs of coarse grained hematite which has replaced all structures and destroyed the details. From the ends of fragments broken along suture lines it is inferred that the first lateral lobe is lower than the first saddle and about two-thirds as broad; terminally it is divided and possibly is trifid. The second saddle is lower Weno and Pawpaw Formations 93 and narrower than the first lobe, and apparently is bifid; it lies at the level of the dorso-marginai tubercles. The second lobe lies on the um- bilical wall and is broad and flat, but from the material at hand its de- tails can not be described. Between it and the tall narrow anti-siphonal lobe there is a depressed saddle-like space. This description and figure of sutures are taken from the individual figured on plate 1, figure 6. Fig. 12. Mortoniceras worthense n. sp., suture of individual, Plate 1, Figure 6, camera lucida drawing, x 10. This species has similarities to Mortoniceras inflatum var. spinosum Pervinquiere1 (Vraconian of Tunis). One individual of five volutions has two gaps in the ribbing of the last volution; they have no obvious relation to the branching or doubling of ribs. The same feature is noted in the earlier volutions in this species. ACANTHOCERAS WORTHENSE n. »P. PI. 1, figs. 11-13, 16-17, 20-25 1920: Acanthoceras sp. Winton and Adkins, Univ. Texas Bull. 1931, p. 69. MEASUREMENTS : PI. 1, fig. 12 PI. 1, fig. 13 Type (I) II Greatest diameter 14.9 mm. 13.8 Height of last whorl 6.0 mm. 6.0 Width of last whorl 6.0 mm. 5.0 Width of umbilicus 1.4 mm.(?) 1.0 HORIZON: Pawpaw formation, basal two-thirds, clay facies. LOCALITY: 723 (type locality), near Fort Worth, Texas; 714, 715, 716, 719, 724, near Fort Worth, Texas. The species is generally abundant in favorably weathered exposures of the clay phase. DESCRIPTION: Shell discoidal, compressed, four or more volutions considerably embracing, umbilicus consequently small ; shell keelless, sec- 'Et. pal. tun., p. 229, pi. xi, fig. 3a-b. 94 University of Texas Bulletin tion of volution roughly oval, venter smooth in young individuals and very slightly convex. In older individuals, however, there is a median broad, low, very rounded swelling, similar to a median tubercle. In young individuals the ribs become obsolete just ventral to the ventral marginal tubercle, but in older individuals the ribs are continuous across the venter. Ventro-marginal tubercles acute, one on each rib, becoming obsolete in the later volutions. Ribs long and short, mainly unbranched. Dorso- lateral (umbilical) tubercles few and scattered. Cross-section of earlier whorls subrectangular, flanks straight, venter lightly convex, dorsum very concave; in later whorls the flanks are more rounded and make an even curve with the venter. In certain young individuals the ribs are flexuous, having a prominent sigmoidal curve, and are much thickened at the mar- ginal tubercle. This individual shows no ribs at a diameter less than 3.8 mm. After that diameter, the intercalated ribs, one or two between some branches, are similar to those of the later volutions. The suture of the species resembles that of young individuals of A. martimpreyi Coquand, as figured by Pervinquiere.1 The considerable Fig. 13. Acanthoceras worthense n. sp., suture, camera lucida drawing, x 8. amount of material at hand does not contain any sutures which are much more complicated than the ones figured here. The suture shows exter- nally besides the siphonal lobe, four saddles and four lobes, which pro- gressively decrease in size toward the anti-siphonal region. The bifid first saddle is more irregular and less square than in the examples of A. martimpreyi mentioned. All the remaining saddles are simple, or bifid, and the lobes are generally bifid. The first lobe is as tall as the first iPervinquiere, Et. pal. tun., p. 294, figs. 109-110. Weno and Pawpaw Formations 95 saddle and about three-fourths as broad. The second and third saddles are taller than broad and rather angular in form. The remaining lobes likewise are subquadrate and shallowly bifid. The internal suture has not been examined. This species greatly resembles Acanthoceras martimpreyi Coquand A. aumalense Coquand, and A. suzannae Pervinquiere, all from the Vra- conian of Tunis. ASTEROIDEA The genera of Comanchean starfishes are in such great need of defini- tion that it has been found impossible to assign the Texas species with much certainty to the proper genera ; for in the absence of authentic ma- terial of described species it is difficult to make such definitions fron< figures and text alone. When the Texas starfishes are closely defined it will probably be necessary to form new genera for certain of the species, but in the meantime they have been provisionally assigned to known genera, avoiding when possible those founded on recent species, on ac- count of the great amount of subdivision which the recent Asteroideo are receiving at the hands of modern workers. PENTAGONASTER TEXENSIS Adkins and Winton PI. 7, fig. 7 1920 : Pentagonaster texensis Adkins and Winton, Univ. Texas Bull. 1945, p. 47, pi. 10, figs. 5-6. 1920: Pentagonaster texensis Winton and Adkins, Univ. Texas Bull. 1931, p. 22. A recently discovered individual shows the superomarginal plates, and the interior of the disk is eroded down to the oral surface, of which several adambulacral, circumoral, and a few paramarginal plates are exposed. All of the superomarginal plates are shown, but due to erosion and the thinness of the disk, certain oral plates come into view, and there is over the disk a resulting mixture of oral and aboral plates. This individual was found in a limestone slab, face down, at the type locality described below. HORIZON : Upper five feet of the Weno limestone. LOCALITY: 602, east slope of the valley of Sycamore Creek, four miles southeast of Fort Worth, Texas, at a level 29 feet below the base of the Mainstreet limestone. 96 University of Texas Bulletin DESCRIPTION: SUPERO-MARGINAL PLATES: On each aboral interarc there are fourteen supero-marginal plates excluding the terminal plate, which is common to each two adjacent arcs. These plates, though separated, seem well preserved, and in this individual as in the type, lack ornamentation. It is entirely possible that better material will show superficial structure on the plates since most related species show it. In shape the plates are trapezoidal or cuneiform, as described for the type. They are tallest and widest at the center of the arc and decrease in size to the tips of the rays. The marginal plates of this species are relatively large and are taller than broad ; in Pentagonaster browni Weller, they are broader than tall, and are relatively smaller. PARAMARGINAL PLATES : These are a row of minute, nearly equal and similar subquadrate plates lying apposed to the inner edge of the marginal plates. Only a few, near the tips of the rays, are preserved in this individual; they apparently belong to the aboral surface. ADAMBULACRAL PLATES : These plates, as described in the type, are mostly quadrate and are of about the same size as the other interior oral and aboral plates (about .5 mm. diameter). This individual has along one radius two nearly apposed rows of plates that belong to this class; they diminish in size somewhat toward the tip of the ray. CIRCUMORAL PLATES: There is a group of plates massed around the mouth region, which are in part oral plates and in part dislocated central aboral plates. They are rounded and larger than the other interior plates, and a few are elongate. In the absence of better material, they can not be described more accurately. INTERMEDIATE PLATES : There are a few continuous radial rows of plates lying on the radii and extending from the center of the disk to the tips of the rays. These are apparently aboral plates. They have a rounded, roughly quadrate to hexagonal shape, and are small, equal and similar. The madreporite and ambulacrai details are not visible. RELATED SPECIES : Pentagonaster browni Weller (Fox Hills form- ation, Lander, Wyoming) is described as having 16 supero-marginal plates which are relatively smaller and less tall than in this species. The inter- radial arcs of the Wyoming species are also deeper than in our material. P. lunulatus Woodward and P. megaloplax Sladen (Upper Chalk, Senonian) differ from the Texas species in having punctate or papillose marginal plates, in the concavity of the interarcs, and in the number of marginal plates. P. robustus Spencer (Upper Chalk) differs in the same charac- ters and in the meeting of the supero-marginal plates along the midline Weno and Pawpaw Formations 97 of the ray; and P. obtusus Forbes (Upper Chalk) is stated to have 18 marginal plates, the superior ones punctate and the two sets alternating. I (type) II R (average of five) 23.5 mm. 15.9 mm. r (average of five) 14.8 mm. 9.9 mm. R/r 1.58 1.6 METOPASTER HORTENSAE Adkins and Winton PI. 7, fig. 6 1920: Metopaster hortensae Adkins and Winton, Univ. Texas Bull. 1845, p. 46, pi. 10. figs. 2-4. 1920: Metopaster sp. Winton and Adkins, Univ. Texas Bull. 1931, p. 69. 1920: Metopaster hortensae Winton and Adkins, ibid., p. 21. This rare species, which characterizes the basal Pawpaw clay, has very tuberculated and spiny plates. The marginals are covered with closely set, low, rounded tubercles, and at places have adherent clumps of small thick spines. One row of ambulacral pore plates is shown on the type individual. This has two rows of oblique pores, indicating four rows of tube-feet per groove. As already stated, there are six paired supero- and infero-marginals in addition to the terminal unpaired supero-marginal plate, totalling eight supero-marginals and six infero-marginals. The terminal marginal plate is similar to that of Mitraster, which differs from the Texas form in its cycloid contour and in the shape and ornamen- tation of its marginal plates. COMPTONIA WINTONI n. tp PI. 7, figs. 4-5 1920: Comptonia sp. Adkins and Winton, Univ. Texas Bull. 1945, p. 49, pi. 10, fig. 1. MEASUREMENTS: Major radius, about 24 mm. Minor radius (average) 6 mm. DESCRIPTION: Disk flat although somewhat collapsed in the type. Rays elongate, tapering, incomplete in the type; probably the ratio R:r is about 4:1. Minor radius about 6 mm. in the type. Supero-marginal and infero-marginal plates numerous, usually paired, disk relatively small and 98 University of Texas Bulletin the interradial arcs next to the disk paraboloid, sharply instead of broadly curved, and in this respect more similar to Comptonia comptoni Forbes than to C. elegans Gray. The two rows of supero-marginal plates are apparently nowhere in contact throughout the length of the ray. Oral and aboral sides of disk covered with rather small, unequal, polygonal to rounded raised plates. ABORAL SIDE : The supero-marginal plates at the center of the arc are slightly wedge-shaped with rounded interior margins ; their sides con- verge slightly, passing out from the center of the disk. The plates de- crease in size and are more elongate, on approaching the tip of the ray. Over the central part of the arc seven plates have the breadth of about 10 mm. There are probably about 20 supero-marginal plates in one entire arc (the tips of the rays are absent in the type) . Along the center of each ray is a row of radial plates which are larger than the other central plates but not elevated above them. One elevated rounded plate on each interray bears a small circular pore (gonopore). In one interray there are two such plates. Between these plates are more depressed rows of plates arranged so as to make a pentagon with its cor- ners at the interradii. The central radial rows of plates along the rays meet the middles of the sides of this pentagon. The small, raised, oval madreporite is situated excentrically, and bears 9 or 10 radiating mostly divaricate, V-shaped straight ridges. ORAL SIDE : The infero-marginal plates are equal in width and in num- ber to the supero-marginal and lie opposite them or nearly so. The oral surface of this starfish is distinctly broader than the aboral surface, so that the line of junction of the two sets of marginals is situated well aboral to the edge of the disk (and this does not seem to be due to crushing). The infero-marginal plates are subquadrate-cuneiform in profile, but are very thick and rounded at the external edge. No para-marerinal rows of plates are visible. The other plates of the oral face of the disk, which are poorly preserved, are also not in rows. The five ambulacral grooves are distinct but without perceptible structure in our material. The num- ber of rows of tube feet is unknown. The grooves are prominent, and have near the peristome a breadth of about .6 mm. The marginal and other larger plates are covered by rather fine, low, round, irregularly scattered tubercles. Evidences of spine pits and pedicellariae are absent. The species differs from Comptonia elegans Gray in several noticeable features. The disk is practically flat in our species; it however, shows some evidence of flattening in preservation, since the central plates are considerably and abruptly depressed below the level of the supero-marginal Weno and Pawpaw Formations 99 plates. Comptonia elegans on the other hand has a central ridge of very rounded elevated plates running the length of each ray and connecting to form on the disk a central, narrow, elevated ring. In our species the center of the disk is flat and the plates are very little disarranged, since the depression mentioned above has not disturbed the relations of the central plates to each other. Calliderma and Nymphaster differ from our species in many notable features. Both have the aboral interadial areas in most species confined to the disk, so that the supero-and infero-marginal plates meet over most of the length of the ray. This is not true in the Texas species. Both genera named were described from recent species, the genotypes being Nymphaster protentus Sladen1 and Calliderma emma Gray.2 This species differs from Comptonia elegans Gray in several important respects. The disk is practically flat in our species; it, however, shows some evidence of flattening in preservation, since the central plates are considerably and abruptly depressed below the level of the supero-marginal plates. Comptonia elegans, on the other hand, has a central ridge of very rounded elevated plates running the length of each ray and connecting to form on the disk a central narrow elevated ring. In our species the center of the disk is flat and the plates are very little disarranged, as the foregoing description shows. PENTACEROS AMERICANUS n. sp. PI. 7, figs. 1-3 MEASUREMENTS: R (average of two) 45.0 mm. r (average of five) 10.4 mm. R:r 4.33:1 A species having the form of Pentaceros jurassicus Quenstedt and in most respects agreeing with the described generic characters, is here re- ferred to this genus. HORIZON: Base of the Pawpaw formation, clay fades, TYPE LOCALITY: 714, one-fourth mile south of the International and Great Northern Railway bridge across Sycamore Creek, four and one-half miles southeast of Fort Worth, Texas. One individual, the type, was found here. Sladen: Narrative of Challenger Exp., 1886, vol. 1, p. 612; Zool. Chal. Exp., part li, Report on the Asteroidea, 1889, p. 294. Fisher, W. K., Starfishes of the Philippine seas and adjacent waters. U. S. N. M. Bull. 100, vol. 3, p. 261, 1919. 2Gray: Proc. Zool. Soc. Lond., part XV, 1847, p. 76; Ann. Mag. Nat. Hist., 1847 vol. XX, p. 198; Synopsis of Species of Starfish, British Museum, 1886, p. 7. 100 University of Texas Bulletin TYPE INDIVIDUAL : A well preserved individual showing both sides of the disk in great detail and having two complete and three fragmentary rays. Museum of Texas Christian University, Fort Worth, Texas. DECRIPTION : Marginal plates distinct, subrectangular on edge view, rounded on the face, bearing fine tubercles. Inter-marginalia pres- ent in the interarcs and the proximal half of the rays, decreasing in size outwards from the disk. Disk relatively small, arcs sharply rounded, rays long and slender; oral surface flat with numerous small plates; aboral surface with a central raised pentagonal system of plates and a row of radiating plates on the midline of each ray. ABORAL SIDE : The rays are slender and the interarcs sharply curved. Each interarc contains from tip to tip of the rays 48 supero- marginal plates (17+7 in each half arc) . Of these all except the terminal seven of each ray are elongate in the direction of the ray, sharply rounded on top and separated from those of the opposite side of the ray by radial plates. The terminal seven plates of each margin of the ray are apposed along the mid-line; the plates are transversely elongate and join by alter- nate facetting, along a zigzag line; the terminal plate is unpaired and is common to the two rows. The seven terminal plates are swollen and smooth and present a very different appearance from the others. In the type they are smooth and whitish, lacking the iron stain of the rest of the animal. A single row of radials extends from the inner pair of these terminal plates to a polygonal elevation in the center of the disk, the plates increasing in size towards the disk. Between this row of plates and the supero-marginal plates there are two parallel rows of plates, an adradial row of large plates fitting into the spaces between the radialia, and a para-marginal row of small cuboidal plates lying against the marginal plates, there being about three of these plates to one marginal plate. The interradial areas on the disk are triangular and are covered with three or four rows of small plates lying close to the marginals; at the apex of each area is a perforated, elevated polygonal plate, the genital plate with its gonopore. The radial ridges running on the mid-line of the ray near the disk are composed of three irregular rows of large rounded ossicles and numerous smaller scattered plates, which were apparently imbedded in a membrane. The central polygonal ring-like elevation at their union bears scattered large and small ossicles. The anus is sub- central and large ; the madreporite is excentric, raised, hexagonal in shape, depressed in the center, and has coarse imbricated V-shaped ridges, and straight, simple or branching ridges, radiating from the center. ORAL SIDE : The oral side is strikingly flattened, being only slightly compressed along the ambulacral grooves. Its prevailingly smooth ap- Weno and Pawpaw Formations pearance is due to the smallness and flatness of the numerous ptales: #hi(5h make up its area. Infero-marginal plates as described for the supero- marginals, and paired with them; however, there are only six inflated terminal plates separated to the tip of the ray by the ambulacral groove: The common terminal closing plate is restricted to the aboral side. Infero- marginal plates finely granulose. Interambulacral areas of oral side broadly triangular with numerous crescentic, coarsely granulated small plates in roughly concentric rows. An adambulacral row of plates with combs of spines lies next to the ambulacral grooves. Between these and the marginals is one row of plates over most of the length of the ray, but on approaching the inter- radial areas other rows enter. Peristome central, apparently protected by fine incurved spines. The species resembles in form Nymphaster radiatus Spencer (Lower Chalk, Upper Cenomanian), from which it differs in the shape and orna- mentation of its marginal plates. It also has resemblances to Pentaceros boysii Forbes and P. squamatus Forbes, both from the Upper Chalk of Kent, England (Senonian), but it differs in these in its form and in the ornamentation of the plates. ECHINOIDEA LEIOCIDARIS SP. Cidarids are known from all the Texas Washita formations above the Fort Worth limestone. These are undescribed and their tests and spines unrelated with one exception, Leiocidaris hemigranosus Shumard from the Denton formation, of which spines and test have been found in such close proximity that they almost certainly belong to the same animal. Cidarid plates, apparently of a Leiocidaris, are abundant in the Quarry limestone group of the Red River region and with them occur great num- bers of spines. In addition, in the Pawpaw clay and in the Grayson marls there are several different species of large cidarid spines. In the Main- street limestone well preserved cidarid tests are known. Cidarid sp. 1, spine: The commonest echinoid spine of the Quarry group has the following characteristics : The shaft bears about sixteen carinae which are made up of rows of rounded, bead- like tubercles, whose tips are slightly pointed down the shaft. The rows are even topped and depressed. On some spines certain carinae are elevated considerably above others and are longer, more prominent, and have a sharp serrate keel and a triangular cross-section. The spine is a short oval in cross-section. Below the tip of the shaft several, in part alternate, carinae end, and the remaining ones become more elevated 102 University of Texas Bulletin p.nd- sharp keeled, .giving to the shaft a Cereus-like appearance. At the base of the spine there is an inflated sharp topped milled collar; the condyle is constricted and the articulating surface deeply excavated. Locality: 601, near Gainesville, Texas; widely distributed in North Texas. Cidarid sp. 2, spine: Cidarid spines of medium length, the shaft not inflated. The shaft bears about 30 depressed, even topped, equal and equally spaced continuous lines. The base is gently inflated and straight sided down to the collar. The collar is not milled and is rounded, making a wide angle with the shaft. The straight margin of the base below the collar descends to the rim of the circular articulating socket. This spine differs from the preceding in having numerous nonserrate carinae. Locality: 601, pit of brickyards, near Gainesville, Texas. Cidarid sp. 3, spine: Spines with an inflated, club-like shaft bearing about 10 • sharply but unequally elevated, smooth keeled carinae and a prominently constricted neck. The margins of the base above and below the collar are smooth and straight and make at the collar a rounded angle of about 135 degrees. The rim of the cir- cular articulating socket is a ring-like thickening. Cross section of inflated shaft ang- uJar and subcircular. Locality: 601, pit of brickyards near Gainesville, Texas, Quarrj limestone. GONIOPYGUS .p. A species of Gonipygus from the basal five feet of the Pawpaw forma- tion clay facies, locality 714, near Fort Worth, Texas, is in the hands of Professor F. L. Whitney for description. PEDINOPSIS SYMMETRICA (Cragin) 1893: Dumblea symmetrica Cragin, Geol. Surv. Texas, 4th Ann., Kept., p. 150, pi. xxiv,1 fig. 12; pi. xxv, figs. 4-7; pi. xxvii, fig. 1. 1915: Pedinopsis symmetrica Clark, U. S. G. S., Mon. LIV, p. 64, pi. xxiii, figs. 1 a-h Three individuals of this species found in the basal Weno marl, locality 618, near Fort Worth, Texas, have been placed in the hands of Professor F. L. Whitney for description. PELTASTES sp. A poorly preserved individual somewhat similar to a Peltastes found in the topmost stratum of the Mainstreet limestone at Denison, Texas, was found at locality 714, near Fort Worth, Texas, in the basal stratum of the Pawpaw clay, and it is referred to this genus. These echinoids will be described by Professor F. L. Whitney. Erroneously cited as pi. xxxiv by Cragin and Clark. Weno and Pawpaw Formations 103 SALENIA sp. A large flattened Salenia, resembling in form S. mexicana Schltiter, which is not known to range so high, was found in the basal stratum of the Weno formation, just on top of the Gryphea washitaensis shell con- glomerate of the Denton marl, by the St. Louis and San Francisco Railway track, two and one-half miles north of Denison, Texas. The following are some of the features of this individual: There are about 20 pairs of ambulacral tubercles, obliquely situated ; the ambulacral lips are considerably wider than the inter-ambulacral lips ; the apical sys- tem ("cap") is large, the plates ornately scalloped; the sutures are widely and irregularly excavated. . ^ Salenidae have so far been found at the following levels in the Texas Comanchean : Buda: S. volana. Grayson: Peltastes sp.: Goniophorus sp. Mainstreet: . Pawpaw: Peltastes? sp., Salenia volana. Weno: Salenia sp. aff. texana. Denton: Goniophorus sp. Duck Creek marl: Goniophorus sp. Duck Creek limestone: Salenia sp. Goodland limestone: Salenia mexicana, S. texana, Salenia n. sp. Walnut: S. mexicana; S. n. sp. Glenrose: Salenia n. sp. CYPHOSOMA VOLANUM Cragin This widespread Upper Washita species is occasional in the Weno form- ation, marl facies, in association with a considerable echinoid fauna and other fossils, such as Turritella worthensis, Venericardia worthensis, Remondia ? acuminata and Ancycloceras bendirei. It is known otherwise from the Weno to the Buda limestone. HOLECTYPUS LIMITIS Bose This species is distinguished from Holectypus planatus Roemer by hav- ing the periproct in length about half the radius of the test and situated about halfway between the centrally located peristome and the ambitus, while the Holectypus planatus the periproct occupies almost the entire length between the peristome and the ambitus. This species, described from subdivision 5 of Cerro de Muleros (Duck Creek and Fort Worth formations) occurs in the Upper Washita beds of North Texas as 104 University of Texas Bulletin Holectypus planatus does in the Lower Washita and Fredericksburg beds. It is scattering in the Weno and Pawpaw formations but more abundant in the echinoid horizon at the base of the marl phase of the Weno forma- tion, in association with Enallaster bravoensis, E. wenoensis, Hemiaster riovistae, Epiaster wenoensis, Pedinopsis symmetrica and Holaster. It is sparse in the Mainstreet formation and has a zone of abundance near the base of the Grayson marl. HOLASTER sp. aff. SIMPLEX Shumard HORIZON: Weno formation, marl facies, abundant near base; Paw- paw formation, marl facies, occasional near top. LOCALITIES: 611, 612, 618, 715, 716, 718, near Fort Worth, Texas; 721, 722, near Riovista, Texas; cut of Missouri, Kansas and Texas Railway, one mile north of Union Station, Denison, Texas, between localities 605 and 606. The common Holasters of the Weno and Pawpaw formations have close similarities with the low phase of Holaster simplex Shumard of the Duck Creek and Fort Worth formations, but are specifically distinct. How- ever, it is considered best to defer their description awaiting better ma- terial. These echinoids occur as eroded mud-filled, calcite tests and the ambulacral areas and apical system are almost invariably damaged. Tests ovoid in outline, non-angular, anterior notch shallow, longer than tall, greatest perimeter generally above the base. Ambulacra flush with surface, postero-laterals in some individuals more divergent than in H. simplex; peristome transverse, oval, lying in a de- pressed space near the ambitus. Peripcroct low, ovoid, vertically elongate lying in tall individuals beneath a prominent posterior median projection. Apical system subcentral elongate. It should be borne in mind that the Holasters of the Weno marl are diverse, and that among them Holaster simplex may occur, since its known stratigraphic range extends into the upper Fort Worth limestone. The species of Holaster closely related to H. simplex Shumard of the Duck Creek and Fort Worth formations, and found in the Weno and Paw- paw formations shows the same variation in form as the lower species; sloping individuals with their greater perimeter at the base, and top-heavy individuals with the greatest perimeter above the base, are common, the latter being most abundant. This species seems to differ from H. simplex in the shape of the madreporite which is elongate instead of subquadrate and in details of the apical system. Since such species are not easily de- finable by form alone, it has been thought advisable not to describe the Weno and Pawpaw Formations 105 Weno species until more material is available. Cragin1 described three species of Holaster, some of which are valid species. Holaster supemus Cragin (Grayson marl, Argyle, Texas), a top-heavy echinoid with a cir- cular apical system, is a Stenonia. The small low species, H. nanus, from the "Vola bed" (Mainstreet?) on the Denison-Bonham road, Choctaw Creek, Grayson County, Texas, is apparently the same low species that is common in the Weno and Pawpaw formations throughout North Texas. The other species, H. completus, which was found in the "Denison beds" and the Mainstreet limestone in Goyson County, has a very distinctive apical system, but has the periproct infra-marginal, and is not a Holaster. In addition, a very small pyritic Holaster whose characters are too im- perfectly known to warrant description, occurs in the basal Pawpaw clay. EPIASTER WENOENSIS n. sp. PI. 6, fig. 6 MEASUREMENTS: Type: Length 54 mm. Breadth 50 mm. Height 29 mm. Apical system to posterior border 32.5 mm. HORIZON : Weno and Pawpaw formations, most abundant in the basal third of the Weno, marl facies, in association with Holaster sp. aff. simplex Shumard, Enallaster bravoensis Bose, E. wenoensis n. sp., Hemiaster cal- vini Clark and H. sp. aff. bexari Clark. LOCALITIES: 618, near International and Great Northern Railway track, three miles southeast of Fort Worth, Texas (type locality). 602, 611, 612, near Fort Worth, Texas ; near Riovista and Blum, Texas ; three miles north of Gainesville, Texas; Missouri, Kansas and Texas Railway cut one mile north of Union Station, Denison, Texas; and elsewhere gen- erally distributed in the North Texas Weno. Localities 714, 715, 718, 723, and other Pawpaw localities near Fort Worth, Texas, especially in the upper marly portion of the Pawpaw. DESCRIPTION : Superficially similar to Hemiaster elegans Shumard, but smaller, smoother, less inflated, less bulged between the ambulacral grooves, and with straighter and narrower ambulacra. The species re- sembles E. aguilerae Bose, but is smaller and differs in the form and am- bulacral details. The Texas Comanchean Epiasters may be distinguished 'Cragin, Geol. Surv. Texas, 4th Ann. Kept, pp. 165-168. ' 106 University of Texas Bulletin from Hemiaster calvini and others by the absence of a conspicuous tubercle between the pores of a pair in the unpaired ambulacrum and usually by the larger size, the slighter depression of the ambulacral grooves, and the shape of the test. It is stated that Hemiaster has peripetalous fascicles while Epiaster lacks them ; but this character is of no value in the usual Texas material, which entirely lacks fascicles. Hemiaster elegans and Epiaster aguilerae are of large size, while Hemiaster whitei and Epiaster wenoensis are of medium and small size. Test: Inflated, rotund, smooth, ambulacra nearly straight, only slightly depressed. Widest point of test just anterior of apical system, tallest point on mid-line posterior to apical system and one-third the distance from it to the ambitus. Sides inflated, rather straight, greatest peri- meter at bottom. Aboral side nearly flat, peristome region excavated, with a projecting keel on the posterior lip and the grooves of the antero- laterals and the anterior sulcus slanting into the peristome. Posteriorly on the oral mid-line the test is inflated, the most prominent point being near the posterior end of the test. Ambitus rounded, with only an antero- lateral angulation just back of the point where the antero-lateral ambul- acra cross the ambitus; posteriorly the test has a rounded outline. Test narrowed to a pointed, very narrowly truncate posterior end. Unpaired ambulacrum lies in the shallow anterior sulcus, which is sim- ilar in form to the other ambulacral grooves, but slightly narrower. Each one has about thirty-one pairs of short slit-like pores set at a slight angle to each other. Antero-lateral ambulacra diverge at an angle of about 150 degrees, then turn forwards slightly, being thereafter almost straight to the am- bitus. Pore zones similar, with the pores almost equal. Each zone has about fifty pore pairs, the pores being short, slit-like, and not set at an angle to each other. Both pores of the anterior zone and the anterior pores of the posterior zone are equal ; the posterior pores of the posterior zone are about one and one-third times as long. Postero-lateral ambulacra long, straight, diverge at an angle of about 60 degrees. About fifty-four pore pairs in each zone, pores slit-like, sim- ilar and nearly equal, the interior ones being, however, shorter than the exterior ones. Peristomal ambulacral pores. The ambulacra after crossing the am- bitus continue as smooth finely granulated strips of large plates with reduced pores, and end at the peristome. However, on approaching the peristome the pores become conspicuous and are borne on elevated knobs with a crater-like opening to one side of the top. These are present in the following Texas species examined : Epiaster wenoensis n. sp. (most Weno and Pawpaw Formations 107 prominent), E. aguilerae Bose, Hemiaster elegans Shumard, H. whitei Clark, H. sp. ( Fredericksburg division), H. calvini Clark. The antero- lateral rows are conspicuous, consist of eight to nine cup-like elevations decreasing in size outwards from the peristome, the cavities opening out- wards and forwards in the anterior row, outwards and backwards in the posterior row. Each cavity bears two nearly circular ambulacral pores, placed obliquely. The antero-lateral and postero-lateral craters make two V-shaped rows at their junctions back of the peristome. The postero- lateral rows each contain about five similar, smaller craters which are lower and more widely spaced farther from the peristome. Peristome oval, the long axis transverse, the anterior curvature being even, the posterior margin with a central, bluntly rounded, elevated, for- wardly projecting lip. Periproct rather similar to that of Epiaster aguilerae Bose: shape trapezoid with the bottom and top rounded, the two superior angles being sharply rounded and the superior margin but slightly arched; the sides diverge, making the periproct broader at the bottom than at the top; the inferior angles are broadly rounded and the inferior margin likewise, it being nearly the arc of a circle of the same diameter as the periproct. RELATED SPECIES: Epiaster wenoensis n. sp. is smaller than E. aguilerae Bose; is more narrowed and pointed posteriorly; is less ele- vated medially just posterior to the apical system, but farther posteriorly is more straight-topped, the slope to the periproct being relatively abrupt ; the notch made in the ambitus by the anterior sulcus is shallower and less pronounced than in E. aguilerae; the peristomal ambulacral pores are larger and more pronounced, more numerous and more crowded than in any other Texas species examined ; the species is more smooth in appear- ance and more sparsely tuberculated aborally than E. aguilerae Bose or H. elegans Shumard. The relations existing between Hemiaster, Epiaster and Macraster in the Texas Comanchean have not been satisfactorily solved. Hill1 and Clark- have considered Macraster texanus Roemer3 to be synonymous with Hemiaster elegans Shumard.4 Roemer and Bose5 state that this species comes from the Fredericksburg division, but Hill6 says that| it "makes a well defined horizon near the very top of the immense thickness of lower iHill, Annotated Check List, etc., Geol. Surv. Texas Bull. 4, p. 2, 1889. 'Clark and Twitchell, U. S. G. S. Mon. LIV, p. 88, 1916. "Roemer, Neues Jahrb. f. Min., Geol. p. Pal., Bd. I, pp. 191-195. Tf. VI, 1888. 'Shumard, Pal. Exp. Red River of La. in 1852, p. 210, pi. II, fig. 4a-c, 1853. 5B6se, Inst. Geol. Mex. Bol. 25, p. 173, 1910. "Hill, On the Occurrence of Macraster texanus, Amer. Nat., XXIII, p. 68, 1889. 108 University of Texas Bulletin marine Cretaceous in Texas" (Buda limestone?) and is "not as Dr. Roemer infers from the specimens which accompanied it to Germany: with the Exogyra texana fauna, a statement which has been verified by Mr. George Stolley, the collector." The distinction between Hemiaster and Epiaster revolves around the presence or absence of fascicles, and Clark' refers Epiaster elegans Auctt. to the genus Hemiaster "as better material has shown that peripetalous fascicles are present although poorly developed and commonly destroyed on most specimens." There seems no a priori reason for doubting this statement until well preserved material demonstrates the contrary. Epiaster aguilerae Bose,2 a distinctive species of the lower Fort Worth limestone, described from subdivision 5 of Cerro de Muleros near El Paso, is here redescribed by comparison with E. wenoensis n. sp., an analagous a'nd equally distinct species from the Upper Washita beds of North Texas. In the collections of the Department of Geology, University of Texas, is an unlabeled echinoid, probably an Epiaster wenoensis, and marked with a red T, as many of Cragin's types were marked, but whether this is a type, and of what, is unknown. Its dimensions, length 36.5 mm., breadth 34.0 mm., height 17.0 mm., do not agree with those of any Epiaster men- tioned by Cragin, who described Epiaster electus (Travis Peak forma- tion), E. elegans var. praenuntius (Comanche Peak limestone), E. hem- iasterinus (Grayson formation), and E. whitei Clark (Travis Peak, Comanche Peak and Fort Worth formations). Since Cragin's species are unfigured and the types apparently lost, they are considered invalid species. The present species differs from Hemiaster whitei Clark in being much less tuberculate, in having narrow straight ambulacra in shallow grooves instead of wide ambulacra in deep grooves ; the form is much wider, more broadly rounded posteriorly, and distinctly lower; the slope anterior to the apical system is steeper. In appearance this species can not be con- fused with the common H. whitei Clark of the North Texas Goodland lime- stone. Epiaster hemiasterinus Cragin is considered by Clark3 as identical with Hemiaster whitei, and Cragin admits4 the "probable identity" of the two. It is described as being tall, with deep ambulacral grooves. iClark and Twitchell, U. S. G. S. Mon. LIV, p. 88, 1916. 2B6se, Inst. Geol. Hex., Bol. 25, .p. 173, pi. 47, figs. 2-4, 67; pi. 48, figs. 1, 2, 4, 1910 3Clark, U. S. G. S., Mon. LIV, p. 89, 1915. 4Cragin, Geol. Surv. Texas, 4th Ann. Kept., p. 155, 1893. Weno and Pawpaw Formations 109 EPIASTER AGUILERAE Bose PI. 5, fig. 5; PI. 8, fig. 7 1910: Epiaster aguilerae Bose, Inst. Geol. Mex., Bol. 25, p. 173, pi. 47, figs 2-4, 6-7; pi. 48, figs. 1, 2, 4. 1920: Epiaster aguilerae Winton and Adkins, Univ. Texas Bull. 1931, p. 68. MEASUREMENTS : Bose's type I II mm. mm. mm. Length _ 77.2 66.2 48.0 Width 69.1 65.5 43.5 Height . 39.0 32.0 24.0 Apical system to posterior margin 43.9 37.0 29.0 Two individuals from the basal Fort Worth limestone near Fort Worth are referred to this species, which was described from Subdivision 5 (Fort Worth formation) of Cerro de Muleros on the basis of one imperfectly preserved individual. The individual figured in this paper is of the same proportions as Bose's individual but about one-seventh smaller. It differs also in having the antero-lateral ambulacra diverge at a greater angle, and in being slightly taller and longer from the apical system back : but the last two features mentioned are due in part to a small amount of end- wise crushing suffered by this fossil. In other respects it agrees with Bose's description. This echinoid is proportionately broader and shorter than the typical Fort Worth limestone, Hemiaster elegans Shumard, of the form figured by Adkins and Winton1 and has a decidedly rounded, non- angular contour as compared with that species. It will be noted also that the ambulacra are narrower, more flexuous (near the ambitus), and sunk in much shallower grooves-than in H. elegans. The madreporite is smaller than in H. elegans- or in Macraster texanus Roemer.3 No fascioles are visible. In longitudinal section H. elegans is much taller, straight-sided and less evenly rounded posteriorly than E. aguilerae, and its inter-ambul- acral areas, including the median posterior keel more elevated. In the individual at hand the periproct is situated lower than in material of H. elegans collected in the Fort Worth limestone at Fort Worth, but higher than in examples figured by Clark,4 and the anterior notch is deeper than in Clark's figures but shallower than in some material collected by me. 'Univ. Texas Bull. 1945, pi. 8, fig. 3. "Compare Clark, in Clark and Twitchell: U. S. G. S. Mon. LIV, pi. XL1II. 3B6se: Inst. Geol. Mex. Bol. 25, pi. XLVIII, figs. 1-3, 5. 'Clark, ibid., pi. XLII, fig. 1-4. 110 University of Texas Bulletin It is evident that the group of Hemiaster elegans of the Fort Worth lime- stone is in an unsatisfactory taxonomic condition and contains more than one species. The other individual of Epiaster aguilerae is smaller but similar in proportions to the one figured here. Like it also, the widest point is just anterior to the apical system and the contour is rounded; the form of the test is longer and somewhat more pointed posteriorly. The long- itudinal section is essentially the same. The periproct is situated higher and is perceptibly taller and less rounded, being pointed at both ends. HORIZON: Basal Fort Worth limestone. LOCALITY : Subdivision 5 of Cerro de Muleros ; Individual 1, one-half mile east of Texas Christian University, Fort Worth, Texas, locality 406. Individual 2, one-half mile southeast of Mt. Olivet Cemetery, Fort Worth, Texas, lower 10 feet of Fort Worth limestone. EPIASTER SUBOBESUS n. sp. PI. 11, fig. 3 MEASUREMENTS : Length, 89 mm. ; Width, 78 mm. ; Height, 52 mm. HORIZON : Top five feet of Weno formation, marl facies ; Pawpaw formation, marl facies. TYPE LOCALITY: 720, top of Weno limestone, one mile southeast of Riovista, Texas. DESCRIPTION : Test rotund, elevated, tapering posteriorly to a very narrow tall truncation sloping forwards at the bottom in the top of which the very small periproct is located. Contour same as E. wenoensis except more prolonged posteriorly; form straighter sided, much more elevated than that species, apical system proportionately farther forward. Base nearly flat, slightly raised on the posterior mid-line, but much less than in E. wenoensis, excavated for the peristome. Ambulacra straight, arranged as in E. wenoensis, inter-ambulacral areas notably more elevated. Un- paired ambulacrum with about 60 similar slit-like pore pairs obliquely set. Antero-laterals very long, with 90 or more pore pairs in each zone; all pores equal and similar ; postero-laterals with 80 or more pore pairs, equal similar slits. Peristome medium, transversely oval, 6.5x6.0 mm. ; periproct extremely small, circular, 3.5 mm. diameter, much smaller and situated relatively lower than in E. wenoensis. The description applies to the type individual. This species might be taken as an old individual of E. weno- ensis, but this is precluded by the differences cited above. The species having this characteristic size and form, is common in North Texas. Weno and Pawpaw Formations 111 ENALLASTER The genus Enallaster ranges from the Neocomian to the Turonian, but is especially abundant in the subtropical Cenomanian seas, where its great development and exuberance of closely related species constitute a special and complicated problem. The littoral deposits of the Mediterranean and the Texas regions contain a sequence of poorly defined Enallasters, in which the separate species are probably closely restricted in vertical range and on careful study will prove to have great stratigraphic value; the two areas mentioned have closely similar species. Enallaster differs from Holaster and Stenonia in having the ambulacra! pores sunk in ambulacral grooves instead of being flush with the surface ; it differs from Hemiaster and Epiaster in the exceptional depth of the anterior unpaired ambulacral groove and in the arrangement and length of the pore zones of the unpaired ambulacrum whose pore pairs are of alternate sizes instead of equal. Enallasters are of very diverse form, one group being flattened and short-ovoid, one group depressed but very elongate, and a third group rather tall and of elliptical contour. As defined by Cotteau, Enallaster contains only species in which the anterior unpaired ambulacrum contains alternate long and short pore pairs. Hemiaster differs from Enallaster in having the pore pairs of the unpaired ambulacrum slit-like and similar, and the pores of a pair sepa- rated by a rounded tubercle. The Texas species of Hemiaster are diverse and fall into two general groups. A. Postero-laterals very short, biconvex, apical system placed far back on test ; anterior row of antero-laterals with pairs of minute circular pores, form low, with long anterior slope. H. longisulcus (Adkins and Winton)1. H. riovistae Adkins. B. Postero-laterals long, more nearly straight, apical system nearly central ; anterior zone of antero-laterals with larger slit-like pores ; form more elevated and inflated. H. calvini Clark. H. elegans Shumard^ H. whitei Clark. H. sp. (Goodland limestone). H. comanchei Clark. Erroneously referred .to the genus Enallaster. 112 University of Texas Bulletin ENALLASTER WENOENSIS n. sp. PL 5, figs. 3 MEASUREMENTS : I (Type) Length 25.0 mm. Breadth 23.4 mm. Height 14.3 mm. Length from apical system to posterior border 9.0 mm. HORIZON : Upper five feet of Weno formation, marl facies. Base of Weno: base of Pawpaw clay. LOCALITY : 720 (type locality) , one mile southeast of Riovista, Texas, and one-half mile east of the Waco road ; 602, 618, near Fort Worth, Texas. DESCRIPTION— TEST : Test oval in general outline, broadest point anterior to the center, less elongate and more abruptly truncated poster- iorly than H. riovistae n. sp. : anterior notch more pronounced than in that species and anterior groove shorter. Apical system located a little less than two-thirds the way back on the mid-line. The outline of the test seen from above is ovate, with angulations ; the anterior corners of the test are broadly round to the notch of the anterior sulcus, the posterior corners on the ambitus are abruptly rounded to the excavated periproct area. Oval surface inflated medially, the most prominent point being on the mid-line about two-thirds the way from the anterior end of the test. Aborally the highest point of the test is on the carina midway between the posterior ends of the short postero-lateral ambulacra and the test slopes gently anteriorly from this point, as in E. bravoensis Bose, and H. riovistae. Anterior unpaired ambulacrum sunk in the deep anterior sulcus which is relatively shorter and narrower than that of H. riovistae n. sp. Each zone has about 31 pairs of ambulacral pores. About the first twelve pore pairs are short, similar and equal except that they increase in size from the apical system anteriorly. They have each two equal short slits separated by a tubercle. Next come five pore pairs, three long and two short, alternating. Next come two groups of two short pairs each, alternating with long pairs. Thereafter anteriorly the pores are short and similar. Throughout this series in all the short pairs, the pores of a pair are separated by a tubercle, which in all the long pairs is lacking. The type agrees with this description. The narrow ambulacral plates, reaching the mid-line, have each two transverse rows of variable sized tubercles, irregularly arranged. Weno and Pawpaw Formations 113 Anterolateral ambulacra: Diverge from apical system at angle of 180 degrees, then turn forward, their middle parts making, if produced, an angle of about 45 degrees with each other ; then turn laterally and cross the ambitus at a point posterior to the anterior corner of the test. The anterior pore zone has 18 to 20 small, circular, closely spaced pore pairs. The posterior zone has about 27 pairs of slit-like pores, the anterior pore being much shorter. Posterolateral ambulacra: Short, inflated centrally diverge at angle of about 130 degrees from each other. Each zone has about 12 pore pairs, those of the posterior zone being more elongate than those of the anterior zone. In each zone the anterior pore is shorter than the posterior. Apical system: Four genital plates, their conspicuous thick-lipped per- forations making the four corners of a square. Oculars small, perforated. Peristome: Ovoid, depressed, posterior lip straight, with an elevated median carina behind it. Periproct: Ovoid, inferior margin extended downward; situated at top of vertically excavated area in posterior truncated area. This species is most similar to E. bravoensis Bose, from which it differs in many particulars. E. bravoensis in form resembles E. texanus (Roe- mer) and is the inflated texanus-like species which is widespread in the upper Washita and which has been so frequently mistaken for E. texanus. We have examples of it from the Weno to the Grayson formations, and it has been found in the Buda limestone (Whitney) . E. bravoensis is not so tall as E. texanus and is not therefore so inflated as. that species ; yet it is more rotund than E. wenoensis* and lacks the angular contour of this species. E. wenoensis is more ovate in form and does not have the long posterior narrowing of the test seen in many individuals of E. bravoensis. It is abruptly narrowed posteriorly and has a truncate posterior end. There is variation in the figured material of E. bravoensis in this regard, and in the absence of a designated type individual it is impossible to say which condition is typical for that species. Bose's plate XLI, figure 5, shows an individual in which the posterior narrowing is slight and the truncation is broad, as in E. texanus or E. mexicanus; in plate XLII, figure 9, the narrowing is prolonged and the truncation narrow, as in E. wenoensis. However, a constant and distinctive feature of E. weno- ensis is that the posterior end of the test is not merely truncate but is deeply excavated vertically, and in this excavation the periproct lies. In E. bravoensis as figured, the apical system is subcentral or at least far- ther forward than in E. wenoensis; the main limits of the antero-laterals therefore diverge at a wider angle (about 80 degrees) in E. bravoensis; 114 University of Texas Bulletin and this position of the apical system is to some extent correlated with the elongation of the test. The anterior ambital notch in E. wenoensis is always sharper and deeper than in E. bravoensis; in the latter species it has the same form as in H. riovistae here described, while in this respect E. wenoensis and H. longisulcus (Adkins and Winton) are closely similar to each other. In E. wenoensis there is a conspicuous high point on the median .carina halfway between the apical system and the posterior end of the test; in E. bravoensis and H. riovistae the carina is low and the highest point is variable, often lying near the apical system. E. bravoensis in addition has a distinctly angular inferior inflation to the test which in our species is evenly rounded. ENALLASTER BRAVOENSIS Bose PI. 8, fig. 4 1910: Enallaster bravoensis Bose, Inst. Geol. Mex., Bol. 25, p. 168, pi. 41, figs. 5-10; pi. 42, figs. 2-12; pi. 43, figs. 1-2, 6-7. 1916: Enallaster bravoensis Whitney, Bull. Amer. Pal. No. 26, p. 16, pi. 6, figs. 3-5. 1920: Enallaster bravoensis Adkins and Winton, Univ. Texas Bull. 1945, p 58 pi 9 fig. 11. This species is occasional in the Upper Washita formations, Weno to Buda, and in North Ttexas is still unknown from the lower formations. At Cerro de Muleros it is reported from subdivisions 5, 6, and 8 (Fort Worth to Grayson). This species differs from Enallaster wenoensis, which also is truncated and tapering posteriorly, by its more elevated and in- flated form, smaller depth of ambulacral grooves, and its taller and dif- ferently shaped longitudinal section in which the anterior slope is shorter, more abrupt and more rounded. ENALLASTER sp. aff. TEXANUS (Roemer) There are in the Upper Washita formations undefined species similar in form to Enallaster texanus (Roemer). These are abundant in the Weno and Grayson marls, and are in need of study and revision. HEMIASTER CALVINI Clark PI. 5, figs. 1, 2, 4; PL 6, fig. 3; PI. 8, fig. 6 This species may be recognized by its tall rounded form and its short, deep ambulacral grooves. It is somewhat variable in form and size, but Weno and Pawpaw Formations 115 the most common variants are here figured. Form elevated ; outline angular, broadly truncated and shallowly ex- cavated posteriorly, with a shallow anterior ambital notch, widest just posterior to the antero-lateral ambulacra. The apical system is a little posterior to the center of the test, the distances in front of and behind it having the ratio 10:8. Ambulacra deeply excavated, the unpaired one being longest; the antero-laterals are longer than the postero-laterals (ra- tio 9:7) ; the antero-laterals diverge at an angle of about 105 degrees, the postero-laterals at about 45 degrees. The unpaired ambulacrum is slightly wider than the others. The posterior median keel and the interambulacral areas are elevated, the former being sharp-topped. Peripetalous fascicle visible but irregular. Pores of unpaired ambulacrum short, slit like, oblique, separated by a prominent tubercle. Pores of lateral ambulacra elongate transverse slits which are nearly equal in the forward and the rear zones. Peristome elongated transversely, with a prominent thick- ened posterior lip; periproct high, vertically elongate, ovate. The longi- tudinal section is distinctly elevated, posterior slope straight and inclined, anterior slope rounded, the highest point of the test being on the posterior median keel just back of the apical system. HORIZON: Weno to Buda formations. The Weno marl contains another species which has deeply excavated short ambulacra, much constricted at each end and flared in the middle. These ambulacra are remarkably short and inflated and have a very characteristic appearance. The whole ambulacral system is placed for- wards on the test, the posterior median keel and the interambulacral areas are elevated, she outline is almost circular and non-angular, the form is low, and the anterior median notch is shallow. This species has some resemblance to the poorly figured and described species Hemiaster bexari Clark. HEMIASTER RIOVISTAE n. sp. PI. 6, fig. 4; PI. 8, figs. 2-3,5 MEASUREMENTS : (Type) Length on mid-line 25.5 Width 23.5 Height 14.0 HORIZON: Top of Weno formation, marl facies. LOCALITY: 720 (type locality), one mile southeast of Riovista, Texas, and one-half mile east of the Waco road. 116 University of Texas Bulletin DESCRIPTION— Test: This species has nearly the form of Enallaster bravoensis Bose, but differs in many respects, notably in having the pore pairs of the unpaired ambulacrum all similar. Test low, elliptical in gen- eral outline, notched at the anterior ambitus, rounded laterally, with three distinct angulations, broadly truncate posteriorly. Anterior sulcus long, apical system situated slightly more than two-thirds the length of the mid-line from the notch of the anterior sulcus. Highest point of test on the low posterior median carina about one-fifth the length of the test from the posterior end. From this point the mid-line curves sharply poster- iorly to the top of the truncated posterior end. This point is only slightly taller than the edges of the anterior sulcus just in front of the apical system. Slope of test forward from apical system gentle, almost a straight line, similar to that of E. bravoensis Bose. The middle is the most inflated point on the test. Inferiorly the most prominent point is on the mid-line three-fourths the way back from the anterior end ; the shell therefore is tallest at this point and anteriorly is wedge-shaped, as in E. bravoensis Bose. There is an elevated median tuberculated area and the peristome lies in a deep depression of the recurved anterior sulcus and is bounded posteriorly by an overhanging pointed lip. Margins of shell sharply rounded on approaching ambitus, and coarsely tuberculate. Around each tubercle is a circlet of small tubercles, and the intervening spaces recovered by- fine granules irregularly scattered. Oval projections of postero-lateral ambulacra consisting of large smooth elongate plates with scattered tubercles and fine granules. Laterally the test bears sev- eral fascicle-like bands each consisting of three crowded rows of the smallest sized granules. Anterior unpaired ambulacrum: Long, shallow, sides nearly straight, making a rather shallow notch at the ambitus. Each pore zone has about 32 pairs of transverse slit-like pores, the pores of a pair being separated by a conspicuously elevated, transversely elongate tubercle. The pores are similar and the ten nearest the apical system show a graduation in size; the others are approximately equal, except near the ambitus, where they are more nearly circular. The pore pairs lie each on an elongate ambul- acral plate which reaches the middle. Each plate has a double row of small granules. Antero-lateral Ambulacra: Diverge at an angle of 180 degrees and turn forward making over the central part of their course an angle of about 47 degrees with each other. They then diverge and cross the am- bitus far anteriorly. The anterior pore zone consists of about 22 pores of minute, closely spaced, circular pores, situated for the most part about Weno and Pawpaw Formations 1J7 the diameter of a pore apart. These are situated in the antero-median quadrant of a quadrate or trapezoidal ambulacral plate which bears two or three large tubercles. The posterior zone consists of about 32 pairs, each having an anterior oval pore and a posterior wedge-shaped slit nar- rowest at the forward end. Postero-lateral ambulacra: Short, rather wide and bulging in the cen- ter, axes straight diverging at an angle of about 115 degrees from each other. The anterior zone has about 12 pairs of short slits; the posterior about 14 pairs of nearly equal longer slightly oblique slits. All of these pores decrease in size toward each end of the zones. Apical system: Four genital plates, the right anterior one being the elongated madreporite, the posterior pair slightly farther apart than the anterior pair ; four perforated oculars. Peristome: Transversely oval with a slightly emarginate lip. The lip posteriorly is elevated into a blunt high tip or carina. Periproct: In shape an oval, transversely situated but with the rounded inferior margin slightly bulged downward; each diameter (on the type) about 2.8 mm., situated high on posterior truncated surface two-thirds the way up. Aside from generic characters the following differences will assist in separating H. riovistae n. sp. from Enallaster wenoensis n. sp. E. weno- ensis has the apical system farther forward; the antero-laterals diverge at a slightly greater angle ; the anterior ambital notch is deeper and more sharply incised; the form is broader, less elongate, more nearly circular, distinctly less flat and more constricted posteriorly. The area in which the periproct lies is not merely truncate, but is sharply excavated giving a narrow vertical groove, while in H. riovistae the posterior end of the test is broadly truncate and the excavation is broad and shallow; and the pores of the anterior unpaired ambulacrum are in part alternating long and short pairs, instead of being all similar and separated by a tubercle as in H. riovistae. The more posterior position of the apical system of H. riovistae results in its having a longer anterior sulcus, it being inter- mediate in this respect between E. wenoensis and H. longisulcus. The an- tero-laterals are in many individuals which are here referred to E. weno- ensis much more sunken than in H. riovistae. The only other described species with which H. riovistae might be confused is E. bravoensis which has long and short pore pairs in the anterior unpaired ambulacrum instead of having all the pore pairs similar. H. longisulcus (Adkins and Winton) has these pore pairs similar, but it is at once distinguished by its lower, more elongate form, and by the unusually long anterior sulcus and the con- sequent posterior position of the apical system. 118 University of Texas Bulletin PELECYPODA NUCULA NOKONIS n. sp. PI. 10, figs. 12-16, 19-20 MEASUREMENTS : I Length 17.0 mm. Height 13.4 mm. Thickness 8.3 mm. HORIZON : Blue shale and red clay-ironstones of upper half of Weno formation, Red River region. LOCALITY : 601, pit of brickyards, one and three-fourths miles south- east of Gainesville, Texas (type locality) ; 604, cut of Frisco track, three- fourths mile north of Union Station, Denison, Texas. DESCRIPTION : Shell inequilateral, sub-equivalved, 'sub-triangular in contour, with fine radial ribs. Right valve, exterior: Beak sharply rounded, angle 100 degrees; a straight rounded ridge runs from the umbo to the anterior angle, making with the anterior margin a long low triangle* whose other two sides are almost straight portions of the anterior margin. These portions are in length as two to one, the dorsalmost portion being the lunger, and make with each other an angle of 15 degrees. The ventralward portion, if ex- tended, would make with the extended ventral side an anterior angle of 60 degrees; the actual angle is sharply rounded. The ventral margin is gently convex downward, and extends backward to the sharply rounded posterior angle (90 degrees). The postero-dorsal margin is straight. The ornamentation consists of about 47 very flat low radial ribs which are unbranched and continuous from beak to ventral margin. Between these lie fine straight depressions one-sixth to one-eighth the width of a rib. The ribs are crossed by fine scalloped growth lines with the convex- ities pointed ventrally, giving to the growth lines a fine crenulate appear- ance. On the anterior area (lunule) the ribs disappear and the growth lines thicken slightly. This area contains a radial anterior ridge and a concurrent posterior depression ; the growth lines in crossing these are crenulate. TWO deeper concentric constrictions representing stages of growth lie in the ventral half of the valve. On the shorter posterior area (escutcheon) the growth lines turn dor- sally and passing over a radial depression and a radial ridge, converge to the margin. Right valve, interior: The rounded, posteriorly directed beak is slightly elevated over the posterior margin. This margin is gently convex over Weno and Pawpaw Formations 119 its dorsal three-fifths and bears a taxodont series of nine teeth of which the two dorsalmost and the one ventralmost are shorter and narrower than the others. The antero-ventral two-fifths of the margin is concave and lies just posterior to the truncately elliptical scar of the post-adductor muscle. The posterior end of this margin is the posterior angle, from which the rounded ventral margin runs to the anterior angle. This margin is more sharply rounded near the posterior angle. The antero-dorsal mar- gin is distinctly bulged, and its dorsal two-thirds bears a taxodont series of twenty teeth, which taper in size at each end. Beneath the umbo is a narrow triangular pit directed downward and anteriorly; and posterior to it is a parallel tooth containing along its length, except at the top, a sulcate depression. Left valve, exterior: The beak is rounded and forms an angle of about 105 degrees. The posterior area is contained between the straight post- erior margin and a curved ridge which is the arc of a circle. In this area the growth lines turn sharply dorsally and converge at the margin. In its center is a radial elevation on whose outer surface are irregular crenu- lations which are oblique to the growth lines and continuous with those on the main portion of the valve. Lateral to the elevation is a concurrent depression and dorsal to it a small plane area. The posterior angle is 100 degrees. The ventral margin is curved ; and more sharply so at the posterior end. The anterior area is a triangular space included between the convex anterior margin and a concurrent but divergent ridge which runs from the beak to the anterior angle. It bears numerous^ coarse crenulations which are continuous with those over the main body of the valve. The ornamentation of the valve consists of numerous radial simple flat ribs similar to those of the right valve; and concentric depressions and growth lines. The two valves fit together evenly with a slight ventral gape. Left valve, interior: This valve is essentially similar to the right valve. Anterior to the beak and ventro-lateral to the taxodont series of teeth is an elongate tooth pointed antero-ventrally and fitting into a socket in the right valve. Its end lies below the tenth tooth anterior to the beak. Type individual: This description is compiled from three individual? of which the first, showing the exterior of the right and left valves, is to be considered the type individual. It and the other two, as many of the other individuals, were found in the blue marl of the upper half of the Weno formation, 20 feet below Quarry limestone in cut of Frisco track, one mile north of Union Station, Denison, Texas (604). 120 University of Texas Bulletin NUCULA WENOENSIS n. »p. PI. 10, figs. 10-11 MEASUREMENTS: I (type) II III Breadth 8.5 10.2 13.0 Height 14.9 17.5 18.5 Length 20.5 23.7 26.0 HORIZON : Weno formation, blue shale, Red River region, occasional ; clay ironstone, occasional. LOCALITY: 604, Frisco cut, three-fourths mile north of Union Sta- tion, Denison, Texas (type locality) ; 601, pit of brickyard, one and three- fourth miles southeast of Gainesville, Texas. DESCRIPTION: Shell sub-equivalved, moderately inflated, inequi- lateral, beaks placed back of the middle of the valve. Ventral margin a long, sub-elliptical curve, sharply angulated posteriorly, more rounded an- teriorly. Anterior margin long, slightly convexed, beaks opposite, approx- imate; posterior margin shorter than anterior, nearly straight, lacking a prominent incision just posterior to the beaks. Anterior areas cres- centic, together forming an elongate biconvex strip, posterior areas form- ing a strip proportionately shorter but equally wide. These are crossed by plain recurved growth lines. Valves nearly smooth in appearance; ornamentation consists of numer- ous fine. simple radial s^riaeiform ridges, crossed by growth lines and growth rings. These ridges on reaching the ventral border form a slightly incised, non-crenulate edge. Hinge taxodont, essentially as in Nucula nokonis. This species differs from N. hokonis in its form and ornamentation. The anterior margin 'is straighter and longer; the posterior margin is straighter and lacks the sharp notch just back of the beaks, having in- stead a gentle curvature ; the posterior "areas" are much more pronounced in side view, and instead of lying flat are elevated at the line of junction of the valves by a posterior projecting carina. The ornamentation at once distinguishes the two species, for in N. nokonis the radial ribs are very- pronounced and the concentric growth lines on crossing them form a system of prominent squares ; the concentric ribs on approaching the an- terior border become zigzag or wavy making a conspicuous V-shaped an- gulation, and in the same region the concentric ribs become crenulate and lamellated. The radial ribs form a prominent scalloped edge at the ven- tral margin of the valve. Weno aud Pawpaw Formations 121 ARCA WASHITAENSIS n. »p PI. 10, fig. 6 MEASUREMENTS : I (type) II III IV V Length 9.2 12.6 8.1 6.7 8.0 Height 7.0 9.5 5.0 '4.9 6.2 Thickness 6.6 9.5 5.6 4.6 6.4 <• Length of -hinge line 7.3 9.9 6.8 5.7 7.0 HORIZON: Pawpaw formation, clay faciea, widely distributed, John- son to Denton counties ; ironstone and sandstone f acies, widely distributed, Denton County to east of Bennington, Oklahoma. A similar, and prob- ably identical species of Area occurs in the Grayson marl and clay at Burleson and Roanoke, Texas; in the Denton clay at Denison, Texas; and in the Duck Creek marl, Grayson to Johnson counties, Texas. LOCALITIES: 714, near Fort Worth, Texas (type locality), all Paw- paw localities in the Fort Worth region. This fossil is found wherever Pawpaw fossils occur, in Denton, Tarrant and Johnson counties, and practically so in the Red River region. Its zone of abundance is one of the most reliable markers of the Pawpaw formation. DESCRIPTION: Shell small, valves very inflated, subequal inequi- lateral, taller posteriorly than anteriorly. Beaks prominent, remote, pro- jecting, rounded, situated slightly anterior to the center of the shell. An- tero-dorsal margin short, concaved; posterior margin longer and nearly straight. Anterior margin short, sharply rounded, ventral margin long and nearly elliptical, dorsal margin broadly rounded. Hinge line long and straight and marked by a crenulated thin ridge in casts of the in- terior. The shell gapes slightly at its posterior end. The valves are orna- mented by numerous low, fine, subequal radiating striae, which equal in width the valleys between them ; and a few (7 or more) unequal, coarse concentric ridges lying mainly on the ventral half of the valve. This Area may be distinguished from others described from the Texas Comanchean strata by its form and size. It is a very characteristic pyrite and hematite fossil and is widespread geographically in the Pawpaw form- ation, and in addition appears to have considerable vertical range, reap- pearing in the Upper Washita in association with pyritic Engonoceras, Turrilites, Hamites, Scaphites and starfishes with each invasion of the clay and ironstone phase of deposition. 122 University of Texas Bulletin GERVILLIOPSIS INVAGINATA (White) 1888: Dalliconcha invaginata White, Proc. Acad, Nat. Sci., Phila., p. 35, pi. 2, figs. 4-5. 1889: Gervilliopsis invaginata Hill: Geol. Surv. Texas Bull. 4, p. 9. 1896: Gervilliopsis invaginata Stanton and Vaughan, Am. Journ. Sci., IV series, vol. 1, vol. 1, pp. 21-26. 1910 : GervUleia invaginata Bose, Inst. Geol. Mex., Bol. 25, p. 87. 1920: Gervilliopsis invaginata Adkins and Winton, Univ. Texas Bull. 1945, p. 67, pi. 18, fig. 1. This shell abounds in the lower Weno of Cooke County, where on fresh exposures it is found with the nacreous shell intact. It has a restricted vertical range and is a reliable marker for the basal Weno north of the Brazos River. It has not been reported from South Central Texas. Stanton and Vaughan, however, record the species from subdivision 6 (Weno-Pawpaw) of Cerro de Muleros. OSTREA CARINATA? Lamarck The known distribution of carmata-like species in Texas has already been published.1 Pervinquiere- has figured types of Ostrea carinata Lam- arck ; and Texas material is now being assembled for a critical study and comparison with related European material. Oysters of the group of 0. carinata and widespread in North, Central and West Texas at different stratigraphic levels, and among them a zone of abundance of the smaller forms in the upper part of the Weno limestone (Quarry group of North Texas) and a scattering representation in the Pawpaw formation. OSTREA sp. aff. DILUVIANA Linnaeus There are in the Weno and Pawpaw formations three oysters with zig- zag coarse margins and ribbed valves, resembling the group of Ostrea diluviana. One of these occurs in the Weno and Mainstreet limestones and is similar to that figured by Hill from the Austin Chalk (U. S. G. S.. 21st Ann. Kept., pt. 7, pi. XLV, fig. 2). Another species from the Weno marl is smaller and thinner, and the margins are crenulate (Univ. Texas Bull. 1945, pi. 16, fig. 1). A third unfigured species from the Weno marl has few prominent zigzag ribs of varying height. These species will likely be found to have considerable vertical range. 1 Winton and Adkins, Univ, Texas Bull. 1931, p. 57; Adkins and Winton, Univ. Texas Bull. 1945, p. 59. 2Pervinquiere, Pal. Univ., 3 me ser., 1910, fiches 197-198. Weno and Pawpaw Formations 123 OSTREA (ALECTRYONIA) QUADRIPLICATA Shumard 1860: Ostrea quadriplicata Shumard, Trans. St. Louis Acad. Sci., vol. 1, p. 608. 1879: Ostrea quadriplicata White, llth Ann. Kept. U. S. G. and G. Surv., Terr., pp. 275- 276, pi. 5, fig. 6a. 1920: Ostrea quadriplicata Adkins and Winton, Univ. Texas Bull. 1945, p. 60, pi. 16, figs. 6-10. This species has not been seen above the Mainstreet limestone, where it is rare, or below the Denton marl. It is abundant at the top of the Denton marl, with Ostrea carinata and Gryphea washitaensis ; and at the Weno-Pawpaw contact in the Quarry limestone, with Ostrea carinata. Gryphea washitaensis and cidarid spines. This species is not known in South Central Texas, but is abundant near El Paso in subdivision 6 (equivalent of Weno-Pawpaw). EXOGYRA sp. off. ARIETINA Roemer A small species of Exogyra, juvenile and young adult stages, was found in the basal Weno at locality 611, near Fort Worth, Texas. The evolution of the arietina group leaves large gaps to be filled in ; the group is known from the Goodland limestone, upper third, and the Kiamitia marl (E. spp. aff. plexa, ribbed and non-ribbed), from the Duck Creek limestone (E. plexa) ; the Mainstreet limestone (E. arietina) and the Grayson marl (two species aff. E. arietina). PECTEN INCONSPICUUS Cragin PI. 11, fig. 4 1895: Pecten inconspicuus Cragin, Colo. Coll. Stud. 5, 1894 (1895), p. 61. Cragin's description follows: "Shell small, thin, subcircular, a trifle higher than long, slightly trun- cated anteriorly and posteriorly, right valve gently convex, its outer sur- face smooth except for faint concentric striae and a few remote, subim- bricate growth-lines; umbonal angle sharp at apex, nearly a right angle; anterior ear (imperfect in the type) re-entrant below, as indicated by the direction of the striae upon it, outline of posterior ear marking an obtuse angle, its posterior margin rather more than one and a half times as long as its dorsal. Left valve unknown. "MEASUREMENTS : Height 9.5, length 8.75, convexity of left valve 1 mm. 124 University of Texas Bulletin "OCCURRENCE : On slope of Pawpaw Creek,'east of Denison, Texas, in red ochraceous shell-conglomerate of the Pawpaw clays. The associate fossils are Ostrea quadriplicata, Tapes dentonensis, Yoldia microdonta Turritella seriatim-granulata, Sphenodiscus, Turrilites, etc." Although Cragin's description is very brief and general, it fits a common Weno species of Pecten in many respects; the locality also makes it prob- able that our Gainesville and Denison material is to be referred to Cragin's species.1 HORIZON: Ironstone and shale facies, upper two-thirds of the Weno formation. Basal Pawpaw formation, sand-ironstone facies. Very rare south of the Red River region. "LOCALITY: Cut of St. Louis and San Francisco Railway, one mile north of Denison, Texas (PI. 11, fig. 1) and pit of brickyards, one and three-fourths miles east of Gainesville, Texas. Numerous localities in Cooke and Grayson counties, Texas. In the pit of the Gainesville brick- yard there are extensive sheets of nacreous shells consisting largely of Pecten inconspicuus, Gervilliopsis invaginata and prodissoconchs and later embryonic stages of Gryphea washitaensis. DESCRIPTION : Shell slightly elevated, smooth, jnequivalve, inequi- lateral ; ventral margin almost the. arc of a circle whose diameter is the antero-posterior dimension of the shell. Antero-dorsal margin almost straight, postero-dorsal margin slightly concave near middle and more elevated by a sharp fold above the ear than the antero-dorsal margin • the two make an angle of about 95 degrees at the umbo, the angle being pointed and very slightly rounded at the tip ; the angle made by lines drawn from the extremities of the two margins to the umbo is about a right angle. The umbo projects slightly over the hinge line. Anterior and posterior ears triangular, the latter having a longer base along the margin than the former, and having nearly twice the area. Hinge line straight, making an angle of about 46 degrees with the antero-dorsal margin and an angle of about 42 degrees with the postero-dorsal margin. The term- inal angle of the anterior ear is about 95 degrees; of the posterior ear, about 100 degrees. The latter angle is broadly rounded. The ears have fine parallel sigmoid growth line which bend toward the umbo at the hinge line, but at the dorsal margin bend anteriorly and posteriorly and after ascending these margins, course concentrically across 'This species has never been figured, so far as I can discover; the type is presumably in the Colorado College museum, but efforts to get information about it have been misspent. Weno and Pawpaw Formations 125 the valve. The growth lines on the valve are fine but unequal; there are also irregular coarser, more widely spaced imbricated rings. In addition, the right valve and its ears are ornamented with numerous fine striaeiform radial curved elevated costellae which spread fan-wise as they approach the margin; these are irregularly truncated near the ventral margin, and on the ears, by intersection with the coarser radial striae, form a network of small squares. The left valve is apparently slightly concave and has a similar structure to the right valve. PECTEN GEORGETOWNENSIS (Kniker) 1919: Neithea georgetownensis Kniker, Comanchean and Cretaceous Penctinidae of Texas. Univ. Texas Bull. 1817, p. 31, pi. VI, figs. 1-3. 1920: Pecten georgetownensis Winton and Adkins, Geology of Tarrant County, Univ, Texas Bull. 1931, pp. 22, 64, 66. 1920 : Pecten georgetownensis Adkins and Winton, Univ. Texas Bull. 1945, p. 70, pi. 12, figs. 5-6. This species may be distinguished by its form and by the radial grooves located on the center of the primary and secondary ribs of the right or both valves. These grooves, however, occur sporadically on other species of Pecten of the P. subalpinus type. It marks the basal third of the Weno formation, marl facies, and is associated with Turritella worthensis, Ancycloceras bendirei, Remondia acuminata Cragin, Pedinopsis symmetrica Cragin, and numerous widely ranging species. It is widespread and abund- ant. VENERICARDIA WENOENSIS n. .P. PI. 6, fig. 2 MEASUREMENTS (type individual) : Antero-posterior 23 mm. Dorso-ventral . 23 mm. Right-left 18 mm. HORIZON AND LOCALITY: Basal Weno formation, marl facies, locality 618, near Fort Worth, Texas (type locality) ; middle Weno shales, "buff marl," below the main GerviUiopsis invaginata zone, locality 601, near Gainesville, Texas. DESCRIPTION : This Venericardia somewhat resembles V. alticostata Conrad var.: of the Eocene, but has the ribs more strongly imbricated 126 University of Texas Bulletin and the ventral margin less nearly circular.1 I know of no other similar species from the Comanchean. Shell oblique, elliptical in outline except for the projecting, elevated umbonal region. Beaks greatly recurved. Ventral margin almost an el- lipse, sharply curved below the beak, gently curved behind ; dorsal-posterior margin nearly straight. The valves have about 24 sharply raised ribs, which bear remote but unevenly spaced, elevated, nodose imbrications. The lateral dimension of the shell is thick, and the species varies some- what in outline. The hinge and other interior details are unknown. PROTOCARDIA »p. aff. MULTISTRIATA (Shumard) PI. 10, figs. 21-26, 32 This beautiful Protocardia occurs as casts and molds in the clay-iron- stone of the Gainesville brickyards and shows in nacreous preservation the minutest details of the exterior and the interior of the shell. Most frequently the shell has crumbled into a friable powder and falls to pieces as the rock is broken open. It then leaves in the ironstone excellent molds of the exterior of the shells showing the radial and concentric striations of the exterior and the details of the hinge, and casts of the interior showing details of the dentition, the two muscle scars, pallial line, etc. Frequently the shell has been removed by weathering and the ironstone carries a > cavity of its exact shape bounded by the cast and the mold. Rarely in the ironstone but usually in the blue shale, the original shell is preserved intact. The Protocardia group of the Texas Comanchean has not been satis- factorily studied and its species are still poorly defined. As in many other Texas genera this uncertainty can be resolved only by a critical description and photographic illustration of the types. Here as in other genera where new species might have been founded, this has not been done pending a better understanding of the relations of the species already described. Shell inequivalve, inequilateral, biconvex, ornamented with sixteen or more serrate radial lines and about 75 round topped subequal concentric ribs separated by narrow valleys. The dorsal margin of the shell is arcuate interiorly, and anteriorly is more thickened. It bears several im- bricated lamellae parallel to and below the hinge line. The region under the beak is deeply excavated. 'Harris, The Midway Stage, Bull. Amer. Pal., 4, pi. 4, flg. 12. 1896; and, The Lignitic Stage, Bull. Amer. Pal., 9, pi. 11, fig. 1, 1897. Weno and Pawpaw Formations 127 HORIZON : Middle and Upper Weno shale and clay-ironstone. Locality of figured material : 604, cut of St. Louis and San Francisco track,- three-fourths mile north of the Union Station, Denison, Texas ; the species occurs throughout the Red River region, and is abundant at locality 601, pit of brickyards, near Gainesville, Texas. CORBULA WENOENSIS n. .p. PI. 10, figs. 1-4 MEASUREMENTS: I II III Length 10.6 11.6 11.2 Breadth (one valve) __. 3.8 4.4 4.0 Height 7.7 8.1 8.0 Length of rostrum 2.0 2.5 2.5 HORIZON: Weno formation, upper half, clay and ironstone phase, abundant; Pawpaw clay, rare. Abundant in the Red River region. LOCALITIES: 604, near Denison, Texas (type locality); 601, near Gainesville, Texas. Shell small, inequivalve, concentrically ribbed with a truncated rostrum. Right valve, exterior: Form a very irregular quadrilateral ; size small. Viewed directly from above, the valve is roughly pear shaped and consists of a very inflated rotund body and a narrowed and depressed posterior siphon tube or rostrum. The umbonal margin is roughly the arc of a circle whose diameter equals the height of the shell. This border passes by a sharp- pointed curve of 120 degrees into the anterior border, which is almost a straight line making an angle of about 45 degrees with the dorso-ventral axis of the valve. The anterior border passes into the ventral border by a sharply rounded curve which is approximately the arc of a circle one-half the diameter of the dorso-ventral dimension (height) of the shell ; the anter- ior and ventral borders if extended would meet at an angle of about 55 de- grees. The ventral border is very slightly convex and this approximates a straight line through one-half the greatest length of the shell, where it is perpendicular to the dorso-ventral axis. A little anterior to its middle there is slight concavity which involves the lower two or three ribs of the shell. The ventral border now curves upward and posteriorly, reach- ing the narrowed siphon tube. The snout-shaped siphon tube lies opposite the middle one-third of the height of the shell and is roughly a right angled isosceles triangle whose hypotenuse is the line of attachment to the body of the valve. This line of attachment is a narrow constricted or depressed zone which notches 128 University of Texas Bulletin both the ventral and the dorsal margins of the valve and gives to the rostrum an inflated appearance; the notch in the dorsal margin is the deeper and more pronounced one. Posterior to the depressed zone and running slightly divergent to it is a rounded ridge which assumes a con- ical inflation as it approaches the postero-ventral extremity of the ros- trum; on the rostrum dorsal to this ridge is a parallel narrow depression and beyond it a rounded inflation which forms the postero-dorsal extrem- ity of the rostrum. The ornamentation consists of thickened, rounded, concentric ribbings, which are broadly flattened on their tops and descend by almost right- angled sides to small plane-bottomed valleys lying between them. On the dorso-ventral axis the widths of ribbings and valleys are about as 2 to 1. The ribs and valleys decrease in width at the anterior margin and at the constriction of the siphonal tube. The ventral one-half of the shell contains 12 rounded ribbings ; the dorsal one-half contains 17 rounded ribbings of similar form but of constantly decreasing size, and in addition in the umbonal region 25-30 fainter rib- bings which resemble growth lines. These 29 heavier ribbings course posteriorly making broad downward convexities to the region of the siphon tube constriction ; their posterior ends lie in the depressed zone mentioned. They then rise onto the elevated ridge which lies near the anterior end of the rostrum, and course over the inflated rostrum to its dorsal margin. On this elevated ridge the com- ponent growth lines in the ribbings apppear as slight thin imbricated lamellae. Not all of the ribbings run continuously from the anterior to the posterior margin. Towards the anterior margin some of the rib- bings, especially the dorsal ones fuse by twos into broader and more de- pressed flat bands. The ribbings on a whole are more flattened and more consolidated on the anterior margin, and more resolved into growth lines on the posterior margin, in the neighborhood of the siphon-tube. In one ribbing, splitting is seen over the middle half of the shell. In one place a small auxiliary ribbing between two of usual size, is seen over the middle half of the shell. The right valve is. somewhat larger than the opening into which the left valve fits, so that the arched, rotund margins of the right valve enclose an elliptical basin shaped visceral space upon which the reduced left valve lies. Right valve, interior: Viewed directly from above, the cavity of this valve has an elliptical contour except at the siphonal end where the mar- gins of the ellipse are drawn out so that each margin has an inward facing convexity ; the dorsal margin then slants ventrally and posteriorly to meet Weno and Pawpaw Formations 129 the ventral margin. There is also a deep rounded concealed recess under the umbo, from this viewpoint. The anterior adducter muscle scar is a small subcircular basin-like depression with a raised rim whose dorsal border connects with the pallial line, a faint narrow groove which ap- proaches the ventral margin as it courses towards the post adducter scar. This scar occupies a rounded-triangular elevated area lying between two more elevated ridges. The more anterior ridge is a shelf-like lamina which separates the body cavity proper from the siphonal (rostral) extension of the shell; and as it passes umbonally it unites with the more posterior ridge forming a U-shaped junction and enclosing between the two ridges the scar of the adductor muscle. The united ridge continues anteriorly as the ventral edge of a broad excavated pit or socket. The external (prismatic) layer of the valve forms a distinct umbonal imbrication which makes up the dorsal edge of this socket. This inner edge of the external layer passes anteriorly, including the umbo but excluding the tooth against which it is apposed; and proceeds to encircle and parallel the anterior and ventral margins of the valve as far as the ventral border of the rostrum, making an imbricated impression about midway between the pallial line and the ventral margin. The thick external portion is cancellated and penetrated by irregular concentric airspaces formed by the loose apposition of long lamellae. The external prismatic portion makes up .8 of the thickness of the shell ; the inner portion is porcellanous and in places pearly-irides- cent. Rostrum: The inner layer emerges from the body cavity proper onto the rostrum, where it is thrown into two small elevated folds which cross each other almost at right angles and consequently form four depressed spaces sloping away from them at either side. The shorter fold is in the antero-posterior axes, and the longer one is continuous with the um- bonal imbrication mentioned above. DISCUSSION : The description of the unfigured Cragin species C. cras- sicostata, agrees with this species in some particulars, but disagrees es- pecially in the number of concentric ribs. In Cragin's Kansas material this number is "7 or 8 on the basal half of a shell the same number of millimeters high," while in our material the number is 11 to 12. Cragin states that the Kansas and the Denison specimens show "no differences of specific value," but further information of a deciding nature is not forth- coming. Cragin's description of the species, Corbula crassicostata, is as follows:1 Cragin, Colo. Coll. Stud., 5, 1895, p. 61. 130 University of Texas Bulletin "Corbula crassicostata, sp. nov. "Shell triangular-ovate, gibbous ; nearly as broad as high, shorts ; gaping posteriorly by a short, conically inflated, gently truncated rostrum, which is placed high above the base of the shell ; unbones placed in advance of the middle, that of the right valve only moderately high arched, its sum- mit obtuse ; surface ornamented with very coarse, flattish-topped, concen- tric ribs, separated by abrupt, deep narrow intervals. There are seven or eight of the ribs on the basal half of a right valve the same number of millimeters high. "Measurements : Height 7.5, length 10, breadth about 7 mm. "Occurrence: In arenaceous limestone bands of the Kiowa shales at Belvidere, Kansas ; in Nos. 2-4 of the writer's 'Belvidere Section.' "So far as the writer can judge from material now in hand, the similar Corbula that abounds in the condition of casts and molds in Texas, presents no differences of specific value from the Kansas shell above described. The casts show that the pallial line is very sharply impressed." CORBULA BASINIFORMIS n. sp. PI. 9, figs. 7-24; PI. 10, figs. 7-9 MEASUREMENTS : Type- Length 17.4 mm. Height 12.1 mm. Breadth 7.7 mm. Difference in length of valves 2.4 mm. HORIZON : Blue shale and clay-ironstone layers of upper half of Weno formation, Red River region, abundant; Pawpaw clay, occasional. LOCALITIES: 604, cut of Frisco track, three-fourths mile north of Union station, Denison, Texas (type locality) ; 601, pit of brickyards one and three-fourths miles southeast of Gainesville, Texas; numerous other localities in Cooke and Grayson counties, Texas. Rare, as limonite stained casts in the Fort Worth region. DESCRIPTION : Shell small, inequivalve, almost smooth, with a short pointed rostrum. Right valve, exterior: Valve rather inflated, evenly rounded, its out- line almost a truncated ellipse. As seen from directly above, the umbonal angle is about 120 degrees ; the dorso-anterior margin is thereafter almost straight for about one-third the greatest length of shell ; the anterior mar- gin then describes an evenly rounded curve, a portion of an ellipse, which continues to the middle of the ventral margin ; here the margin is more nearly straight, but again curves more sharply dorsally and posteriorly, and reaches the posterior (rostral) angle. This angle is 90 degrees and is very slightly rounded-acuminate. The postero-dorsal margin is almost Weno and Pawpaw Formations 181 straight, having a roughened, striate protruding area — the rostrum — reach- ing to the umbo; and anterior to it is the straight posterior margin of the valve. The greatest height of the valve is near its center. Its convexity is greater on the umbonal margin than on the ventral margin; from the center the surface slopes gently to a line, marked in places by a prominent growth line, below which the surface is curved at a sharply rounded angle of 90 degrees to the margins of the valve, giving to the valve a charac- teristic geniculated and basin-like appearance. The rim of the valve thus slopes inward at all points except on the dorsal margin of the ros- trum, so that the margin of the valve has a smaller circumference than the prominent growth line mentioned above. The ornamentation consists of radial striae and concentric growth lines. The radial striae are fine, unbranched, wavy, or punctate lines which end near the geniculation. The concentric growth lines are more conspicuous (toward the ventral margin they resemble fine ribs), and pass posteriorly, turning sharply dorsally at the line of junction of the main body of the valve and the slightly developed rostrum. They then pass dorsally in straight lines which give to the elongate triangular rostrum a roughened striated appearance. Right valve, interior: As viewed directly from above the interior of the right valve has three prominent contours : the outer one is the margin of the valve ; the middle one is a narrow groove, the junction between the thicker outer (prismatic) shell layer and the thinner inner (porcellanous) shell layer; the innermost contour is the limit of the main body cavity. The first two are the shape of a long ellipse, and are situated a short distance apart ; they begin at the antero-dorsal one-third of the prominent tooth, and run concentrically around the anterior and ventral margins of the valve, making an evenly rounded elliptical curve to the postero-ventral extremity of the rostrum. The innermost contour encloses roughly a sub- quadrate area whose boundary begins at the ventral margin of the tooth and describes a slight curve to the dorsal end of the anterior adductor scar. Here it runs almost straight ventrally with a slight posteriorward convexity formed by the scar, in such a manner that a sharp-edged, cres- cent shaped shelf, elevated above the main body cavity, is formed between it and the middle contour mentioned. The scar is pear-shaped and its inflated ventral end lies at the widest point of the shelf. The shelf con- tinues along the interior of the ventral side of the visceral space to a point one-third the way from the anterior end, and then fuses with the wall of the valve. Just anterior to it lies the pallial line, a narrow groove with a slight and irregular interior elevated crest which descends to the bottom 132 University of Texas Bulletin of the visceral space and proceeds backward to a point underneath the posterior adductor muscle scar. Here it turns backward making a 45 degree angle, then turns straight dorsally, making with its former course a 90 degree angle, and reaches the lower angle of the scar. This rounded triangular scar likewise lies on an elevation formed by the inner contour mentioned, which passes dorsally and anteriorly, then turns anteriorly reaching the ventral border of the tooth. It thus leaves dorsal to it and posterior to the tooth, a kidney-shaped pit, into whose posterior border a small tooth projects. Left valve, exterior: This valve is smaller and distinctly shorter than the right valve, but has almost the same depth. Its smaller length is due to the shortness of the rostrum which fails to cover about one-half the rostral area of the right valve, and thus leave a narrow wedge-shaped gap for the siphon tubes. The left valve is in contour an obliquely truncated ellipse. Seen from above, it has an umbonal angle of about 100 degrees and an almost straight antero-dorsal margin. This continues as a sharply and evenly rounded curve into the ventral margin which is gently curved, but which posteriorly curves more sharply, reaching the tip of the ros- trum. The postero-dorsal margin is roughly a straight line, except for a slight bulging near the posterior half. The valve has a marginal gen- iculation of about two-thirds the height of the corresponding one on the right valve, and consequently a basin-like form for the entire valve. The ornamentations consist of growth lines and weak concentric ribs, of which there are about seven below the geniculation, and 26 or more above it, the ribs decreasing in size in the dorsal one-third of the shell. The ventral one-half of the valve, above the geniculation, bears about 12 ribs. Left valve, interior: This valve has a truncate elliptical margin. It may be divided into two regions : the visceral cavity and the rostrum. The anterior part lacks the prominent shelf seen in the other valve. The visceral cavity is a subquadrate depressed area from which a shallow curved recess extends under the beak. Its margin is separated from the posterior margin of the valve by the triangular shaped rostrum whose inner surface is practically plane ; the dorsal and narrow two-thirds of the triangle is occupied by the elliptical scar of the posterior adductor muscle ; the anterior edge of this scar is smooth and forms the rim of the "shelf" ; from it a perpendicular wall descends to the floor of the visceral cavity. The ventral and wider one-third of the rostrum is the space for the siphon tubes, and is plane with the floor of the visceral space. From the lower end of the posterior adductor scar the narrow ribbon- like pallial line descends ventrally for a short distance, turns sharply pos- Weno and Pawpaw Formations 133 teriorly and then makes an acute re-entrant angle (25 degrees) passing now anteriorly and almost perpendicularly to its former course; it runs in almost a straight line to the anterior one-third of the valve, where it gently curves upward meeting the postero-ventral corner of the scar of the anterior adductor muscle. This scar is roughly pear-shaped and its tip is continuous postero-dor- sally with an elevated ridge which passes along the bottom of the pit for the resilium. Dorsal to it, the elevated margin of the valve runs poster- iorly, stopping short at the middle of this pit. This pit is subcircular and lies anterior to the central tooth just dorsal to its mid-dorsal point is the umbo. Posterior to it is a circular elevation which is separated by a con- stricted neck from the post-adductor muscle scar. LOCALITY : Cut in Frisco railroad, three-fourths mile north of Union Station, Denison, Texas, in Weno marl, 20 feet below Quarry limestone (locality 604). CORBULA LITTORAL1S n. sp. PI. 10, fig. 5 MEASUREMENTS: (Type) length of valve 18.0mm. Length of rostrum 4.0 mm. Height of valve _ 11.5 mm(?) HORIZON: "Buff marl," near middle of the Weno formation, and immediately below zone of abundance of Gervilliopsis invaginata (White) in association with Venericardia wenoensis, Trochus laticonicits, cidarid spines, Trigonia clavigera and Placosmilia sp. LOCALITY : 601, pit of brickyard, one and three-fourths miles south- east of Gainesville, Texas (type locality). A fragmentary right valve, lacking umbo, antero-dorsal margin and posterior half of ventral margin is apparently different from any other de- scribed species, and it is considered best to describe it here. The indi- vidual is rather similar to C. wenoensis Adkins. Right .valve, exterior: The (restored) contour is elongate-triangular, with probably a nearly straight antero-dorsal margin, a sharply rounded anterior angle (probably about 60 degrees), a long nearly straight ven- tral side, curving up only slightly to meet the ventral margin of the ros- trum. The rostrum is short, truncate, and the form of an isosceles tri- angle ; its rounded postero-ventral angle is 100 degrees ; its sharp postero- dorsal angle is 110 degrees; an almost obsolete shallow oblique groove separates it from the body of the valve, forming the base of the isosceles triangle. The postero-dorsal side is nearly straight except for a slight 134 University of Texas Bulletin convexity in its posterior one-third. The valve is distinctly rotund and elevated. The ornamentation consists of 12 coarse rounded concentric ribs, and a number of fine growth lines in the umbonal region; the. ventral half of the height contains nine of the coarse ribs. These ribs turn dorsally along the anterior end of the rostrum and just posterior to the oblique shallow groove, making an angle of 95 degrees to 100 degrees. The ribs near this angle bear each about four or five fine growth lines. The edges of the ribs appear as thin slightly imbricated and overlapping lamellae. Dorsal to the angle, the rostrum is conically inflated, the width of the fold in- creasing postero-ventrally and at the posterior end occupying the whole height of the rostrum. Dorsal to the inflation is a narrow concurrent and slightly divergent depression. The rostrum is half the height of the shell and is very close to the ventral margin. The ribs are unbranched and continuous from the anterior to the posterior ends of the valve. They are elevated with rather sharply rounded tops and are separated by plane bottomed, vertical-sided valleys whose width is one-sixth that of a rib. Remarks: The following species of Corbula are to be found in the literature on the Comanchean : C. pikensis Hill (Trinity division) ; and C. crassicostata Cragin, Kiowa, Kansas, and (by implication) in the "ochreous shell-conglomerate of the Denison beds, Denison, Texas." C. basiniformis is distinguishable from the other species mentioned by its relatively unornamented surface and its geniculate margin. C. littoralis is distinguished from the others by its few coarse elevated and broad ribs ; C. wenoensis is distinguished from C. littoralis by its smaller size, its different and less elongate form, its greater number of ribs, the more dor- sal position of its rostrum, the shape and relative height and position of the rostrum, and by the internal characters as described. CYPRIMERIA WASHITAENSIS n. *p. PI. 9, figs. 1-6 Type MEASUREMENTS: PL 9, fig. 1 PL 9, fig. 4 PL 9,.fig. 2 Height 52.0 52.0 76 Length 58.5 59.0 77+ Breadth 15.0 17.5 25 HORIZON: Weno formation, upper and middle thirds, shale facies. LOCALITIES : 604, cut of St. Louis and San Francisco Railway, one mile north of the Union Station, Denison, Texas (type locality) ; 601, pit of brickyards, three-fourths mile southeast of Gainesville, Texas. Weno and Pawpaw Formations 135 DESCRIPTION: Shell subovate, inequilateral, subequivalve, beaks pointed anteriorly (prosogyrate) ; surfaces of both valves covered with numerous, simple, fine, striaeiform, concentric growth lines, and having a few widely spaced, coarser growth rings. Shell preserved, interior filled with ironstone. The beaks are inconspicuous, recurved anteriorly forming anterior to them a small notch in the margin and are rounded, incurved and approximate ; anterior to them the margins of the valves are in contact and the growth lines are imbricated and separated, making several lines parallel to the margins of the valves. Posterior to the beaks is a much wider triangular depression between the margins of the valve. It runs from the umbo backwards to the postero-dorsal, angle; its bottom is the apposed inner dorsal margins of the valves, its top the separated outer dorsal margins, while its sides consist of growth lamellae terminating abruptly and together constituting the thickness of the valves at this point. The groove in one individual contains over the medial half of its length a well preserved external hinge ligament. This has a chitinous appearance but is replaced by calcareous material. The dentition is approximately that of Cyprimeria Conrad. The hinge of the left valve consists of two posterior lamellae, two teeth and an an- terior lamella. The most dorsal posterior lamella is very broad and ob- lique, and is nearly parallel to the inner dorsal shell margin, which it has overgrown. It is roughly lanceolate or blade-shaped, the point being di- rected toward the umbo, the curved back directed ventrally, the edge di- rected dorsally and a narrowed portion directed postero-dorsally. It is separated by a narrow groove from the shorter second posterior lamella, which lies parallel to it and is coalescent with its umbonal half. Ventral to this lamella there is a narrow, deep, elongated pit, which separates it from the more posterior tooth. This pit in one individual contains a mass of brownish material chitinous in appearance but in fact calcareous. The two teeth are sharp, ridge-like and elongated, making an angle of about 60 degrees with each other; they are remote and are separated by a tri- angular area, raised centrally. Running anteriorly from the base of the tooth is an elongate elevated margin which may be taken as an anterior lamella. Dorsal and parallel to this is an elongate groove which is bounded dorsally by the upturned inner dorsal edge of the valve. Parallel and an- terior to the anterior tooth is a narrow deeper depression the length of the tooth, which anteriorly connects with the groove. Below the teeth is an elongated area of small pits and punctations on the dorsal portion of the inner surface of each valve. Cyprimeria crassa Meek has been recorded1 'Hill, Annotated Check List, p. 14. 136 University of Texas Bulletin from the Eagleford shales near Denison, Texas and Cragin considers it to be widespread in the Fredericksburg division in South Texas. This species is stated to differ from C. texana (Roemer) in its large thickness and size. Cragin1 also records Cyprimeria sp. aff. excavata Morton from the Eagle- ford shales ("top of Ostrea quadriplicata beds"). Still a larger Cypri- meria, called C. gigantea* by Cragin is recorded from the Grayson marl near Roanoke, Texas ; we have found similar individuals in the Grayson at Roanoke, Denison, Burleson and elsewhere. Our species appears to be close to Cyprimeria texana (Roemer) which is known as casts from the Fredericksburg division. One individual of this species at hand shows a simple entire pallial line, some details of dentition, and papillae represeting the pits on the inner surface of the valves below the hinge, as mentioned above in the description of C. washitaensis and as figured by Roemer and Conrad for C. texana. The two species seem to differ but slightly, yet in view of the uncertain systematic position of the Fredericksburg species and its poor preservation it is thought best to describe the present material separately. The relations of the pallial line to the posterior adductor muscle scar are entirely different in the two species and the scar is of a different shape. In a fragment of the left valve of a large individual of C. washitaensis from near Denison the scar is subquadrate in shape and the pallial line attaches directly to its lower anterior corner, while in Roemer's figure3 of the impression of the right valve, the scar is an inclined oval and its postero- ventral end lies in a prominent loop in the pallial line ; this loop is missing in our species. Roemer's species also appears to have a considerably sharper marginal curvature just anterior to the umbo than has C. washitaensis, of which however I have not yet found any interior casts for direct comparison, all of the known material consisting of nac- reous shells. REMONDIA ? ACUMINATA (Cragin) PL 6, fig. 1 This species does not have close similarities in form to that figured by Gabb," yet the hinge is rather similar. Stanton5 has figured and dis- cussed the species of this genus. The hinge is here figured (PI. 6. fig. 1). The species has an acuminate tip, nearly straight antero-dorsal and postero- dorsal margins and a gently rounded ventral margin. Posteriorly the 'Cragin, Geol. Surv. Texas, 4th Ann. Report., pp. 176-7, 1893. 2Cragin, Ibid., p. 176. sRoemer, Kr. Texas, pi. VI, fig. 8a. *Gabb, Geol. Surv. Calif., Pal. II, p. 270, pi. 36, figs. 17-17a, 1869 (Remondia furcata). 5Stanton, Proc. U. S. N. M., XIX, 299-301, 1920. Weno and Pawpaw Formations 137 shell is incurved to form a rostrum-like constriction. There are 8 to 15 roughly concentric, sharply elevated ridges which contract towards the posterior end of the shell. The species is occasional in the lower Weno marl of the Fort Worth region, especially at locality 618, in association with Pecten georgetown- ensis, Ancycloceras bendirei. Schloenbachia wintoni, Turritella worthensis, and Venericardia wenoensis. GASTROPODA AMBERLEYA GRAYSONENSIS n. sp. PI. 6, fig. 5 MEASUREMENTS : ( Type individual ) . Height 21.0 mm. Breadth (estimated) 17.2 mm. Last whorl, height 11.0 mm*. Last whorl, breadth 10.0 mm. HORIZON: Basal stratum of Weno shale, in association with Ostrea quadriplicata, Gryphea washitaensis, Salenia sp. and various echinoids. LOCALITY: 606, just south of Frisco track, two and one-half miles north of Denison, Texas. DESCRIPTION : Shell conical, turreted, spiral angle about 63 degrees (estimated, shell of type distorted) ; volutions three or more, the terminal one being over one and one-half times the diameter of the next smaller one. Volutions angular, projecting, cross-section somewhat pentagonal. The volutions bear externally three coarse revolving ridges, of which the outer ones form the upper and lower shoulders of the volution. These ridges are equal and equally spaced, the distance between them being about two times the width of a ridge. The volution is crossed transversely by lan- ellar growth lines with thin overlapping irregular edges. From the center of the spire these trend sharply forwards, and crossing the first heavy ridge then pass obliquely across the outer face of the volution and after travers- ing the marginal strip of the volution on the other side of the ridges, dis- appear at the suture. They form slightly elevated imbricated low nodes on crossing the three spirals. Umbilicus absent, aperture indeterminate. 138 University of Texas Bulletin TROCHUS LATICONICUS n. sp. • PI. 10, figs. 30-31 MEASUREMENTS : I II Height 9.0 7.8 Greatest width 8.9 8.8 Aperture, height 3.0 2.5 Aperture, width 4.4 4.0 HORIZON: Weno formation, shale facies. Has so far been found only in the zone of Gervilliopsis invaginata (White) . TYPE LOCALITY: 601, pit of brickyard, one and three-fourths miles southeast of Gainesville, Texas. DESCRIPTION: Shell small, conical, angulated. Volutions five of which, two earliest in this type, are nearly smooth. Form trochoid, apical angle 55 degrees, sutures impressed, ornamentation consists of a coarse, revolving spiral on the keel, ten finer spirals above, the alternate ones being coarser and consisting of equal low rounded tubercles, the others being straight fine revolving elevated ridges ; and below the keel ten eqaul similar non-tuberculate spiral ridges, each about half the width of the intervening valley. Growth lines numerous, fine, sigmoid, oblique to the ridges. Umbilicus concealed, small if any; aperture broken; probably obliquely oval. The next tuberculate ridge above the keel is thicker than the others and the keel and it lie just above the suture on the younger whorls and form a distinct angulation at the base of each volution. The shell on the last volution is thick (one half mm.) and the external markings well preserved. Trochus sp. Shattuck1 from the Buda limestone at Austin differs from our species in having a larger apical angle (66 degrees) and straighter, non-angulated sides. Trochus texamts Roemer2 from the Barton Creek (Austin, Texas) fauna of the Edwards limestone differs locally from our species in the nature of the ornamentation, the straightness of the sides and apparently in the shape of the aperture. This species is also described as having a pointed tooth on the inner margin of the outer lip. iShattuck, U. S. G. S. Bull. 205, p. 31, pi. XIX, figs. 2-3. 2Roemer, Pal. Abh., vol. 4, pt. 4, p. 15, pi. 1, fig. 13. Weno ami Pawpaw Formations 139 HELICOCRYTPUS MEXICANUS Bose 1910: Helicocryptus mexicanus Bose, Inst. Geol. Hex., Bol. 25, p. 140, pi. 46, figs. 1-6; pi. 47, fig. 1. A single individual lacking the mouth but otherwise well preserved and agreeing with the original description, was determined by Dr. Bose as be- longing to this species. LOCALITY : 714, near Fort Worth, Texas, in the basal Pawpaw clay. NERITA .p. PI. 10, fig. 28 This fossil is found in the "buff marl" of the Weno brickyards at Gaines- ville, Texas, in association with Trochus laticonicus, Venericardia weno- ensis, and other fossils listed in the geological section of this locality. NERITINA .p. PI. 10, fig. 27 This small calcitic fossil is one of a group of peculiar small fossils as- sociated in the "buff marl" of the brickyard pit, near Gainesville, Texas. The others are Trochus laticonicus Adkins, Nerita sp., Venericardia weno- ensis Adkins, Placosmilia spp., Trigonia clavigera Cragin, Leioddaris spines, Corbula littoralis Adkins, Pecten sp. and numerous widely distrib- uted Weno fossils. • ANCHURA MUDGEANA White PI. 10, figs. 39-40 1879: Anchura mudgeana White, llth Ann. Kept. Geol. and Geogr. Surv. Terr., p. 312, pi. 7, fig. 3a-b. 1889: Anchura (Drepanocheilus) mudgeana Hill, Geol. Surv. Texas Bull. 4, p. 19. 1894: Anchura mudgeana Hill, Bull. Geol. Soc. Amer., vol. 5, p. . 1918: Anchura mudgeana Stephenson, U. S. G. S. Prof. Paper 120-H, p. 141. This common species of the Weno shale at Denison and Gainesville has not been found outside the Red River region, to my knowledge. It is con- spicuous in the ironstone and blue shale layers of the Weno in association with a large nacreous fauna including Corbula spp., Nucula spp., Turritella sp., Cerithium sp., Natica sp., and others. It differs from Anchura pro- labiata White in having a single instead of a double lip ; and from A. ruida 140 University of Texas Bulletin White and A. haydeni White1 in having a rounded, tabulated, externally directed lip instead of an upturned sharply pointed one. It differs from Anchura monilifera Gabb2 found at Arivechi, Sonora, in the less elongate form and greater apical angle, in the greater width of the aperture, and in the tabulated lip. NATICA *p. PI. 10, fig. 29 A small nacreous Natica is known from the ironstone layers of the Upper Weno shale of the Red River region. It is preserved with the slightly altered calcareous shell. Locality 601, pit of brickyards near Gainesville, Texas. LUNATIA »p. PI. 10, fig. 38 This Weno species has a nacreous preservation and occurs in both the Upper Weno shale and the interspersed clay-ironstone seams. It is oc- cosional in the ironstone heap thrown out of the brickyards pit near Gaines- ville, Texas. GLOBICONCHA *p. PI. 10, fig. 41 This large species is rare in the Red River region, and is known from the clay-ironstone layers of the upper part of the Weno shale, in associa- tion with Protocardia sp. aff. multristriata (Shumard), Turritella gray- sonensis, Cinulia washitaensis, Gervilliopsis invaginata, Schloenbachia win- toni, Cambarus ? sp. and other Upper Weno fossils. Locality, 601, near Gainesville, Texas. TURRITELLA GRAYSONENSIS n. sp. PI. 10, fig. 43 MEASUREMENTS : Type, greatest height ----------------------- 36.0 mm. Width of last volution _______________________ 11.5 mm. Section of last volution, height _______________ 7.5 mm. Section of last volution, width ________________ 7.0 mm. e, llth Ann. Kept., U. S. G. and G. S. Terr., 1879. "Gabb, Geol. Surv. Cal., Pal. II, p. 262, pi. 35, fig. 7, 1869. Weno and Pawpaw Formations 141 HORIZON: Weno shale and ironstone, abundant; Pawpaw clay and sand, rare. Rare south of the Red River region. LOCALITY : This is the common nacreous Turritella of the Weno iron- stone and clay at Denison, Gainesville, and elsewhere in the Red River region. Locality 604, Frisco cut three-fourths mile north of Union Sta- tion, Denison, Texas (type locality) ; 601, near Gainesville, Texas. DESCRIPTION: Shell turreted, steep, spiral angle 17 degrees; ten or more volutions, straight-sided, sutures sharply impressed, angles of volutions sharply rounded, surface almost smooth, bearing about fourteen lightly tuberculate spiral lines of unequal height. Of these, ten lie on the side of the volution and four below the shoulder. On the terminal volution of the type these are arranged as follows : Beginning at the suture, the first ridge is strongest and bears widely spaced low obscure tubercles with flat spaces between; the thickness of this rib equals the width of the space separating it from the second rib. The second, fifth and seventh ribs are slightly narrower, but are ribbon- like and low in proportion to their breadth and have slight nodular eleva- tions widely spaced from each other. The other ribs are low, subequal and have rounded tops and slight nodular elevations at wide intervals. The last four ribs lying beyond the shoulder of the volution are relatively nar- rower and more elevated than those on the flanks, and the inner three are closely spaced, being separated by about the width of a rib ; the last rib is more widely separated but is the same size. The rest of the volution next to the umbilicus is smooth except for one or two obsolete spiral ribs. In the intervals between the ribs mentioned there are three to five fine equal raised lines. The transverse growth lines are prominent and sig- moid, and resemble those in T. bravoensis Bdse, but are finer. Aperture unknown ; crass-section of volution sub-quadrate, outer side straight, inner side rounded. This species is separated from Turritella bravoensis Bdse, T. budaensis Shattuck, and T. planilateras Conrad by having the tubercles very low, and depressed, instead of coarse and prominent. It is separated from T. leonensis Conrad, T. marnochi White, and T. denisonensis Cragin in having a greater number of spiral ridges and more tubercles in each ridge. Cragin1 describes without figuring, a variety under the name of T. kan- sensis, which has less crowded revolving ridges than our species. Like- wise, T. seriatim-granulata Roemer2 differs from T. wenoensis in having only five elevated tuberculated ridges, the middle one of which is flanked iCragin, Notes on some fossils of the Comanche series, Science, n. s., vol. 6, pp. 134- 136, 1897. zRoemer, Kr. Texas, p. 39, pi. 4, fig. 12. 142 University of Texas Bulletin on each side by a low, non-tuberculate ridge. The ridges are wider and more prominent than in our species and the intervening spaces much nar- rower ; the tubercles are more widely spaced ; the fine secondary revolving lines are apparently lacking; and the contour is more angular. Roemer's species is also figured as having a smaller apical angle (about 12 degrees). TURRITELLA WORTHENSIS n. sp. PI. 10, fig. 42 MEASUREMENTS: Type length of fragment 26 mm.; width (esti- mated) 14.5 mm. HORIZON: Basal Weno formation, marl facies. Abundant in the Fort Worth region in association with Ancycloceras bendirei, Remondia acuminata and Pecten georgetownensis. LOCALITIES: 618, near Fort Worth, Texas (type locality); exten- sively distributed in Tarrant County, Texas. DESCRIPTION: Shell conical, steeply turreted, apical angle 23 de- grees, with six or more volutions. Shell nearly straight sided, sutures impressed, surface with usually six nearly elevated spiral ridges bearing conspicuous, equal, equally-spaced, rounded tubercles. Beneath this are two parallel thin spiral ridges with obsolete tubercles. These form the bottom of the volution, and the uppermost of the six ridges mentioned, which is longer than the others, forms the top. Between each two ridges are four to six fine non-tuberculate spiral lines, but exceptionally one or two of these may be thickened, giving the appearance of an alternating series of fine and coarse revolving ridges on the volution. In most of the material at hand the six revolving ridges are equally spaced, and are sep- arated by a depression only slightly wider than one of the ridges. The tubercles are equally spaced on all the ridges, and number about 65 on the last volution. These tubercles decrease in size on the earlier volutions, and all are present in the youngest stage examined. Transverse growth lines are not visible. The details of the aperture are not preserved. The cross-section is rounded and triangular, the ex- ternal side of the volution being longest. Below the shoulder of the usually tuberculate volution are about four impressed lines, of which the two al- ready mentioned are not covered by the succeeding volution. Below this point the volution is smooth. Many species of Turritella have been described from the Texas Coman- chean, and some of these are indeterminate, on account oi faulty figures and description, or lack of necessary information concerning stratigraphy and locality. Weno and Pawpaiv Formations 143 The present species is nearly straight-sided and is slightly angulated, while in T. bravoensis Bose1 the middle rows of tubercles form a conspicu- ous angular projection on each volution. The number of rows of tubercles is greater than in Bb'se's species and the tubercles are more crowded in the rows. The conspicuous transverse striated growth lines of his species are absent in our material. T. pkmilateras Conrad2 is somewhat similar in form to our species, but has a prominent alternation of tuberculate and smooth spiral ridges, while in our species the intermediate lines are tuber- culate and do not approach the main ridges in thickness. T. budaensis Shattuck3 has the rows of tubercles diverse, the second row from the suture being most prominent, and the form is more angulated than in our species. T. worthensis is at once separated by its strong tubercles from the faintly tuberculate or granulated species, T. seriatim-granulata Roemer4 (Freder- icksburg, Lower Washita), T. marnochi White,5 T. leonensis Conrad (Fred- ericksburg)6 and T. denisonensis Cragin7 (Mainstreet, Grayson). Ellisor8 has described several species of TurriteUa of which only T. man- chacensis (Buda) and T. washitensis (Buda> seem to approach the present species in ornamentation or form. CINULIA WASHITAENSIS n. .p. PL 10, figs. 33-37 1920: Cinulia sp. Winton and Adkins, Univ. Texas Bull. 1931, p. 66. MEASUREMENTS : Total height 15 mm. Total breadth . 14 mm. Body whorl, excluding lip, height 10 mm. Body whorl, excluding lip, breadth 10 mm. Breadth of lip 4 mm. HORIZON: Weno blue shale and clay-ironstone layers, middle and upper portions of the formation, especially in the Red River region. LOCALITY : 601, pit of brickyards, one and three-fourths miles south- ifiose, Inst. Geol. Mex., Bol. 25, p. 149, pi. 31, figs. 8-9; pi. 32, figs. 1-2, 1910. 'Conrad, Mex. Bdry. Surv., Vol. 1, Pt. II, p. 158, pi. 14, figs, la-b, 1857. "Shattuck, U. S. G. S. Bull. 205, p. 31, pi. XIX, figs. 4-6, 1902. 4Roemer, Kr. Texas, p. 39, pi. 4, figs. 12a-b, 1852. 'White, U. S. G. and G. S. Terr., llth Ann. Kept., pp. 314-315, pi. 7, figs. 5a-b, 1879. «Conrad, Mex. Bdry. Surv., Vol. 1, Pt. II, p. 165, pi. 21, figs. 7a-b, 1857. 'Cragin, Colo. Coll. Stud., 5, p. 65, 1895. "Ellisor, Univ. Texas Bull. 1840, 1920. 144 University of Texas Bulletin east of Gainesville, Texas (type locality) ; 604, cut of St. Louis and San Francisco Railway, three-fourths mile north of Union Station, Denison, Texas. Occasional in Cooke and Grayson counties, Texas. About 25 in- dividuals found. DESCRIPTION : Shell of medium size, sub-globose, total outline sub- elliptical; four volutions, of which the last is much the largest and occu- pies two-thirds the height of the shell. Surface ornamented with evenly rounded equal revolving lines, about 25 on the last volution. Between the lines are concave depressions each about one and one-half times the width of a line. These contain numerous equally spaced vertical cross striations, which run perpendicular to the depressions and to the adja- cent revolving lines. Aperture elongate, rounded-cuneate, narrowed at the top and enlarged at the bottom. Outer lip much thickened and rounded, elongate, extending the length of the two last volutions in the type (slightly shorter in other individuals), and bearing on the inner margin about 14 nearly equal blunt tubercles in two equal groups. The inner lip is flat and expanded and bears on its apertural margin three elevated spiral folds or laminae which project into the aperture ; these are thickened and rounded at their free margins ; the basal two lie almost horizontal while the upper one is directed somewhat downwards and is concealed underneath the jnner lip. Viewed from outside the outer lip is very broad and thick- ened and bears about seven irregular coarse overlapping laminae. This species resembles Cinulia tarrantensis Cragin1 of the Goodland limestone near Fort Worth, but differs in several respects. C. tarrantensis is poorly described and figured and some of its critical points are inde- terminate, no further material having been discovered from the type locality, Goodland limestone near Benbrook, Tarrant County, Texas. The type apparently is lost, or at least it is not in the other Bumble Survey material at Austin. Cinulia is extremely rare in the Goodland limestone of the Fort Worth region. The species appears to differ from C. wash- itaensis in having a narrow and much less imbricate lip and in having the spire lower in proportion to the length of the lip. In Cragin's species the lip does hot seem to reach the top of the body whorl, while in the type of our species it is more elongate, extending the whole length of the term- inal and next adjacent whorls instead of only three-fourths of the term- inal whorl. In some other individuals it is lower, but never so low as in C. tarrantensis. The figure of C. tarrantensis shows the angulation of the turns above the body whorl to be pronounced, while in our species also differs in numerous details. The outer lip is broader in proportion Cragin, Geol. Surv. Texas, 4th Ann. Kept., p. 223, pi. XLII, fig. 1. Weno and Pawpaw Formations 145 these turns are rounded. The shape of the aperture and of the teeth to the body and bears much coarser imbricated lamellae than in Cragin's species; the aperture is more slender throughout and is noticeably more compressed below; the sub-central crenulate region of the inner edge of the outer lip is distinctly angular ; the inner lip is broader and the three teeth placed differently, the two terminal ones being more closely spaced. Our species is apparently larger than C. tarrantensis, and comes from a higher horizon. The unfigured and indeterminate species Cinula ? texana (Shumard)2 was described from the Fredericksburg division of Bosque County; its description will apply to most species of the genus. C. rectilabrum Gabb1 is a lower species and bears on its inner lip two teeth instead of three; it is more slender, more pointed apically, and has narrower lips and a more elongate aperture. Cinulia pelletti Whitney and C. conradi Whit- ney,3 both. from the Buda limestone differ in several respects from the Weno species, the former in the proportions of the shell, the height and shape of the aperture, and the thickness of the outer lip, the latter in the shape, size and number of costellae. PROTOZOA NODOSARIA TEXANA Conrad PI. 11, fig. 2 This characteristic foraminiferean shell has already been described* in some detail and the features mentioned apply to the Weno and Pawpaw material at hand. The fossil ranges in North Texas through the upper third of the Weno limestone and the base of the Pawpaw clay. The in- dividuals are generally scattered, but also rarely occur in slabs. At Fort Worth there is a zone of abundance at a point about 18 feet below the top of the Weno formation, which is found at this stratigraphic level every- where between the Red River and the Brazos. This zone appears to be different from the common Del Rio Nodosaria zone of West Texas, for prevailingly in West Texas the zone of abundance of Nodosaria is in the top of the Del Rio clay .iust underneath the Buda limestone, and the fossil is scattering in the middle Del Rio clay. Near Del Rio, Texas, where the formation is about 200 feet thick the Nodosaria slabs are prominent near the top, and near the Chisos Mining Company, Brewster County, where iGabb, Geol. Surv. Calif., Pal. II., p. 264, pi. 35, figs. 10-10a. 'Shumard, Trans. Acad. Sci., St. Louis, I, 1860, 597. "Whitney, Trans. Texas Acad. Sci., XII, p. 23, pi. 10, figs. 9-11. «B6se, Inst. Geol. Mex., Bol. 25, p. 177, 1910; Adkins and Winton, Univ. Texas Bull. 1945, p. 76, 1920. 146 University of Texas Bulletin the Del Rio clay is 120 feet or more thick, the zone of abundance of Nodosaria is above the occurrence of Exogyra cartledgei Bose, which lies 10-30 feet below the Buda limestone.1 This level probably corresponds to the Grayson formation of North Texas. Nodosaria is rare at Austin in the middle Del Rio clay. At Cerro de Muleros, which is in the northern facies, it is reported as occurring in subdivision 5 (Duck Creek and Fort Worth), and as abundant in subdivision 6 (Denton, Weno and Pawpaw) ; this is its lowest recorded occurrence.3 BIBLIOGRAPHY Adkins, W. S., and Winton, W. M.: Paleontological Correlation of the Fredericksburg and Washita Formations in North Texas. Univ. Texas Bull. 1945, 1920. (Bib- liography.) Berry, E. W. : The lower Cretaceous floras of the world. Maryland Geol. Surv., Lower Cretaceous, pp. 99-151. Baltimore, 1911. The upper Cretaceous floras of the world. Maryland Geol. Surv., Upper Cretaceous, pp. 183-313. Baltimore, 1916. Bose, Emil: Monografia geologica y paleontologica del Cerro de Muleros, etc. Inst. Geol. Mex., Bol. 25, 1910. On a new Exogyra from the Del Rio clay and some Observations on the Evolution of Exogyra in the Texas Cretaceous. Univ. Texas Bull. 190?, 1919. Cotteau, G.: Echinides, in Paleontologie francaise. Cragin, F. W. : A contribution to the Invertebrate Paleontology of the Texas Creta- ceous. Geol. Surv. Texas., 4th Ann. Rept., pp. 141-294. Descriptions of Invertebrate fossils from the Comanche Series in Texas, Kansas, and Indian Territory. Colo. Coll. Stud., 5, 1895, 49. Dumble, E. T.: The Geology of East Texas. Univ. Texas Bull. 1869, 1920 Grossouvre, A.: Recherches sur la Craie Superieure. I. Stratigraphie generale. II. Paleontologie. Paris, 1893-1901. Haug, Emile: Traite de Geologic. Paris, 1911. Hill, R. T.: The Geology of the Black and Grand Prairies of Texas. U. S. G. S. 21st Ann. Rept., Pt. 7, 1901. Geology of the Territory adjacent to the Red River in Arkansas, Texas. and Indian Territory. Bull. Geol. Soc. Amer., 5, pp. 297-338, 1893. Noetling, F.: Die Fauna der baltischen Cenoman-geschiebe. Pal. Abh., BH. II. heft 4, 1885. Pervinquiere, L.: Etudes de paleontologie tunisienrie. I. Cephalopodes des terrains secondaires. II. Lamellibranches et gastropodes des terrains secondaires. Paris, 1907. Pervinquiere. L. : Sur quelques ammonites du cretace alger'en. Mem. Soc. Geol. France, Paleontologie, tome xvii, fasc. 2-3, Mem. No. 42, pp. 1-86, pis. 1-7 (x-xvi), 1910. 'Bose, Univ. Texas Bull. 1902, p. 19, 1919. -Bose, Inst. Geol. Mex., Bol. 25, pp. 24-26, 1910. Weno and Pawpaw Eormations 147 Richardson, G. B.: Report of a reconnaissance in Trans-Pecos Texas north of the Texas and Pacific Railway, Univ. Texas Mineral Surv., Bull. No. 9, 1904. Sayn, G. : Les ammonites pyriteuses des marnes valangiennes du sud-est de France. Mem. Soc. Geol. France, Paleontologie, tome 9, Mem. No. 23, pis. 1-6 (vi-x, pi. vii repeated), pp. 1-66, 1901. Sellards, E. H.: The Geology and Mineral Resources of Bexar County. Univ. Texas Bull. 1932, 1920. Sladen, P., and Spencer, W. K. : A monograph of the British fossil Echinodermata, Asteroidea. Paleontogr. Soc. Szajnocha, Ladislaus: Zur Kenntniss der mittelcretacishen Cephalopodea-fauna der Inseln Elobi an der Westkiiste Afrika. Denkschr. d. Kais. Akad. Wiss., Wien., XLIX, pp. 1-8, pis. 1-4, 1884. Whitney, F. L.: The Echinoidea of the Buda limestone. Bull. Amer. Pal., No. 26, 1916. Winton, W. M., and Adkins, W. S.: The Geology of Tarrant County. Univ. Texas Bull. 1931, 1920. PLATE 1 Flickia, Schloenbachia, Mortoniceras, Acanthoceras 150 University of Texas Bulletin PLATE l. Flickia, Schloenbachia, Mortoniceras, Acanthoceras Plate 1 Figures 1-3. Flickia boe«ei n. sp Page 85 Rare, basal Pawpaw formation, marl-clay transitional area. Fig. 1, type indi- vidual, side view, x 4.7; fig. 2, same individual, ventra' view, x 4.7; fig. 3, same individual, x 1.33. Locality: 714, near Fort Worth, Texas. Figure 4. Flickia (?) bosquensis n. sp Page 87 Rare, top of Exogtfra arietina horizon, middle Del Rio clay (equivalent of base of the Grayson formation). Locality: cliff on west bank of the South Bosque River, 100 yards south of the bridge of the Speegleville road, and 5.5 miles west of the courthouse at Waco, Texas. Type individual, side view, x 2.0. (See PI. 4, fig. 11.) Figure 5. Schloenbachia sp Rare, basal Pawpaw clay. Locality: 714, near Fort Worth, Texas. Figures 6-10, 18-19, 26. Mortoniceras worthense n. sp Page 91 Abundant, Pawpaw formation, base, clay facies. Fig. 19, type individual, x 4.0. Locality: 723, near Fort Worth, Texas; figs. 10, 26, same locality, x 4.0. Other figures, x 2.0, same locality. Figures 11-13, 15-17, 20-25. Acanthoceras worthense n. sp Page 93 Abundant, Pawpaw formation, base, clay facies. Fig. 12, type individual, x 2.0. Locality: 723, near Fort Worth, Texas. Other individuals, x 2.0, same locality. Figure 14. Schloenbachia wenoensis n. sp Page 89 Rare, Pawpaw formation, base, clay facies. Fig. 14, type individual, x 2.0. Locality: 723, near Fort Worth, Texas. University of Texas Bulletin No. 1856 PLATE 2 Scaphites, Hamulina, Metopaster, Comptonia 152 University of Texas Bulletin PLATE 2. Scaphitei, Baculites, Ptychoceras, Metopaster, Comptonia Plate 2 Figures 1-12. Scaphites hilli Adkins and Winton Page 79 Occasional, basal 10 feet of the Pawpaw formation, clay facies, sparse outside of Tarrant County region. Fig. 1, type individual, x 4.0, ventral view, showing suture and mid-ventral groove. Locality: 714, near Fort Worth, Texas. Fig. 2, individual showing venter with sutures outlined in the hematite and limo- nite areas, x 4.0. Locality: 714. Fig. 3, individual showing suture, dorso- lateral tubercle, and aperture, x 4.0. Locality: 714. Fig. 4, same individual, reverse side, x 6.0. Figs. 5, 6, individuals x 4.0. Locality: 714. Fig. 7, indi- vidual showing uncoiled portion and dorso-lateral tubercle, x 2.0. Locality: 723, near Fort Worth, Texas. Fig. 8, individual showing uncoiled portion, tubercle and juvenile suture, x 4.0. Locality: 723. Figs. 9-12, showing rib variations, x 4.0. Locality: 723. Figures 13, 15-18. Scaphites sp. aff. hilli Adkins and Winton Occasional, Pawpaw clay, base. Fig. 14, x 3.0; figs. 13, 16-18, x 2.0, showing rib variations. Locality: 713, near Fort Worth, Texas. • Figure 14. Metopaster hortensae Adkins and Winton Page 97 Rare, Pawpaw formation, base, clay facies. Type individual, aboral side, x 2.0. Locality: 714, near Fort Worth, Texas. Figure 19. Comptonia wintoni n. sp Page 97 Rare, Pawpaw formation, base, clay facies. Type individual, aboral side, x 3.0. Locality: 714, near Fort Worth, Texas. Figures 20-22. Baculites comanchensis n. sp Page 74 Occasional, Pawpaw formation, base, clay facies. Type individual. Fig. 21, x 4.0. Locality: 719, near Fort Worth, Texas. Fig. 20, x 2.0, same locality. Fig. 21, x 2.0. Locality: 714, near Fort Worth, Texas, Figures 23-26. Hamulina worthensis n. sp Page 71 Rare, basal Pawpaw clay. Type individual, Fig. 26, x 5.0, showing suture. Locality: 714. Fig. 23, individual showing form of curve and short limb, x 4.0. Locality: 714. Fig. 25, same individual, ventral view, x 2.0. Fig. 24, individual showing form of long limb and of curve, x 4.0. Locality: 714. Individuals of Figs. 23, 24 in museum of Texas Christian University, Fort Worth, Texas. University of Texas Bulletin No. 1856 Plate 2 PLATES Turrilites, Acanthoceras, Schloenbachia 154 University of Texas Bulletin PLATE 3. Turrilites, Acanthoceras, Schloenbachia Plate 3 Figures 1, 6. Turrilites worthensis Adkins and Winton Page 78 Abundant, Pawpaw formation, base, clay facies. Fig. 1, x 4.0; locality: 714, near Fort Worth, Texas. Fig. 6, showing portion of suture, x 4.0; locality: 714, near Fort Worth, Texas. Figures 2, 4. Turrilites sp Page 78 Abundant, Pawpaw formation, base, clay facies. x 4.0; locality: 714, near Fort Worth, Texas. Figures 3. 7. Turrilites bosquensis n. sp Page 76 Rare, top of Exogyra arietina horizon, middle Del Rio clay (equivalent of base of the Gray son formation). Locality: cliff on west bank of the South Bosque River, 100 yards south of the bridge of the Speegleville road, and 5.5 miles west of the courthouse at Waco, Texas. Fig. 3, type individual, x 4.0, show- ing tubercles and angularity of profile. Fig. 7, same individual, x 2.0, show- ing aperture. Figure 5. Acanthoceras worthense n. sp Page 93 Abundant, basal and middle Pawpaw clay. Individual showing venter, x 4.0. Locality: 714, near Fort Worth, Texas. Figures 8-11. Schloenbachia wintoni n. sp. . . Pag* 90 Occasional, Pawpaw formation; abundant, Weno formation. Figs. 8, 11, type individual, x 1.0; locality 601, near Gainesville, Texas, nacreous individual from ironstone in upper third of Weno formation. Figs. 9-10, nacreous indi- vidual, x 1.0, same locality. Fig. 9 shows the slightly bifid marginal tubercles. Type in museum of Texas Christian University, Fort Worth, Texas. University o.' Te as Lulletin No. 1856 Plate 3 PLATE 4 Schloenbachia, Engonoceras, Flickia, Corbula 166 University of Texas Bulletin PLATE 4. Schloenbachia Engonocreas, Flickia, Corbula Plate 4 figure 1. Schloenbachla sp Rare, Pawpaw clay, x 4.0. Locality: 714, near Fort Worth, Texas. (See PI. 1, fig. 6.) i Figure 2. Engonocerai sp Page 85 Rare, Pawpaw clay, x 2.5. Locality: 714, near Fort Worth, Texas. Figure 4. Acanthocera* wortheiue n. sp Page 93 Abundant, Pawpaw clay, x 4.0. Locality: 714, near Fort Worth, Texas. Figures 3, 5-6, 12. Engonoceras serpentinum (Cragin) Page 84 Occasional, Weno shale, Grayson and Cooke counties, Texas and southern Okla- homa; rare, Pawpaw clay and shale. Figs. 3, 5, x 2.5; locality: 714, near Fort. Worth, Texas. Figs. 6, 12, x 1.0; locality: 604, near Denison, Texas. Figures 8-10. Engonoceras sp Page 85 Very abundant, Pawpaw clay, especially near the base; rare, Grayson, Denton, and Duck Creek formations, clay and marl facies, x 3.0, locality: 714, near Fort Worth, Texas. Figure 11. Flickia (?) bosquensi* n. sp Page 87 Rare, top of Exogyra arietina horizon, middle Del Rio clay (equivalent of base of Grayson formation). Type individual, x 4.0. Locality: cliff on west bank of South Bosque River, 100 yards south of the bridge of the Speegleville road, and 5.5 miles west of the courthouse at Waco, Texas. (See pi. 1, fig. 4.) University of Texas Bulletin No. 1856 12 PLATE 5 Hemiaster, Epiaster, Enallaster 158 University of Texas Bulletin PLATE 5. Hemiaster, Epiaster, Enallaster Plate 5 Figures 1-2, 4. Hemiaster calvini Clark Page 114 Occasional, Weno and Pawpaw formations; rare, Denton and Mainstreet forma- tions; abundant, middle Grayson formation. Fig. 1, large sized individual with strongly developed ambulacral grooves, x 2.0; locality: Argyle, Texas, Gray- son marl, Baylor University Museum. Fig. 2, individual in some respects re- sembling Hemiaster bexwi Clark, x 3.0; locality: 720, basal Pawpaw marl, near Riovista, Texas. Fig. 4, x 2.0; locality: west branch of Little Mineral Creek, one mile northeast of Fink, Texas. Figure 3. Enallaster wenoensis n. sp Page 112 Abundant, Weno formation, marl facies; rare, Pawpaw formation, marl and clay facies. Type individual, x 4.0; locality: 720, basal Pawi.iaw marl, near Rio- vista, Texas. Figure 5. Epiaster aguilerae Bose Page 109 Rare, basal Fort Worth limestone. Locality: 406, one-half mile east of Texas Christian University, Fort Worth, Texas. Aboral side, x 1.0. Univeriity of Texas Bulletin No. 1856 Plate 5 PLATE 6 Remondia( ?), Venericardia, Amberleya, Hemiaster, E piaster 160 University of Texas Bulletin PLATE 6. Remondia, Venericardia, Amberleya, Hemiaster, Epiaster Plate 6 Figure 1. Remondia (?) acuminata (Cragin) Page 136 Occasional, basal Weno marl; rare, Pawpaw clay. Locality: 618, near Fort Worth, Texas, individual, x 1, showing hinge structure. Figure 2. Venericardia wenoensis n. sp Page 125 Occasional, Weno formation, shale facies, Red River region, and marl facies, Fort Worth region. Fig. 2, individual, x 2.0, showing ribbing. Locality: 618, near Fort Worth, Texas. Figure 3. Hemiaster calvini Clark Page 114 Occasional, Weno and Pawpaw formations. Fig. 3, x 3.0. Locality: 903, Gray- son marl, one-half mile southeast of Denison, Texas. Rare, basal Pawpaw formation, clay-marl transition area; rare, Weno marl. Type individual, x 4.0. Locality: 720, near Riovista, Texas. Figure 4. Hemiaster riovistae n. sp Page 115 Rare, Weno formation, shale facies. Locality: 606, basal stratum of Weno form- ation, near Denison, Texas. Type individual, x 2.0, showing carinae and ribbing. Figure 5. Amberleya graysonensis n. sp Page 137 Abundant, basal Weno formation, marl facies; rare Pawpaw clay and marl. Type individual, x 1.0. Locality: 618, near Fort Worth, Texas. Figure 6. Epiaster wenoensis n. sp Page 105 Abundant, basal Weno formation, marl facies; rare, Pawpaw clay and marl. Type individual, x 1.0. Locality: 618, near Fort Worth, Texas. University of Texas Bulletin No. 1856 Plate 6 PLATE 7 Pentaceros, Comptonia, Metopaster, Pentagonaster 162 University of Texas Bulletin PLATE 7 Pentaceros, Comptonia, Metopaster, Pentagonaster Plate 7 Figures 1-3. Pentaceros americanus n. sp Page 99 Pawpaw formation, clay facies, basal 5 feet, rare. Fig. 1. Type individual, aboral side, x 2. Locality: 714, one-fourth mile south of the International and Great Northern Railway bridge across Sycamore Creek, four and one-half miles southeast of Fort Worth, Texas. The large ~ plate above and to the left of the center of the disk is the madreporite. Type in museum of Texas Christian University, Fort Worth, Texas. Fig. 2. Type individual, oral side, x 2. Fig. 3. Type individual, aboral side, x 1.5. Figures 4-5. Comptonia wintoni n. sp Page 97 Pawpaw formation, clay facies, basal portion, rare. Fig. 4. Type individual, aboral side, x 2. Locality: 714, near Fort Worth, Texas. Fig. B. Type individual, oral side, x 2. Figure 6. Metopaster hortensae Adkins and Winton Page 97 Pawpaw formation, clay facies, base, rare. Type individual, oral side, x 2. Locality: 714, near Vort Worth, Texas. Figure 7. Pentagonaster texensis Adkins and Winton Page 95 Weno formation, limestone facies, upper 10 feet, rare Locality: 602, east bank of Sycamore Creek, about four miles Southeast of Fort Worth, Texas. Aboral side, x 1.5. Figured individual in museum of Texas Christian University, Fort Worth, Texas. University of Texas Bulletin No. 1856 Plate 7 V 164 University of Texas Bulletin PLATE 8. Hemiaster, Epiaster, Enallaster. Plate 8 Figure 1. Hemiaster longisulcus (Adkins and Winton) Occasional, top of Fort Worth limestone. 1/pe individual, x 2.0. Locality: On Cedar Creek, two miles southeast of Blum, Texas. Note the similar pores of the anterior unpaired ambulacrum, and the posteriorly placed apical system. Figures 2-3, 5. Hemiaster riovistae n. sp Page 115 x 2.0. Locality: 720, near Riovista, Texas. Figure 4. Enallaster bravoensis Bosc Page 114 Occasional, Weno formation, marl and clay facies; rare, Pawpaw, Mainstreet and Buda formations; abundant, Grayson formation, marl and clay facies. Fig. 4, individual x 2.0. Locality 618, near Fort Worth, Texas. Figure 6. Hemiaster calvini Clark Page 114 Locality unknown, Cummins Collection. Note position of apical system, and the deep ambulacra! grooves. Figure 7. Epiaster aguilerae Bose Page 109 Rare, basal Fort Worth limestone. Locality: 406, one-half mile east of Texas Christian University, Fort Worth, Texas. (Same individual as PL 5, fig. 5.) Apical system, x 4.0. University of Texas Bulletin No. 1856 Plite 8 PLATE 9 Cyprimeria, Corbula 166 University of Texas Bulletin PLATE 9. Cyprimeria, Corbula Plate 9 Figures 1-6. Cyprimeria washitaensis n. sp Page 134 Occasional, Weno shale, Cooke and Grayson counties, Texas Fig. 1, type indi- vidual, x 1.0; locality: 604, near Denison, Texas. Figs. 2-4, x 1.0, same locality. Figs. 3-5, individuals showing hinge structure, x 1.0, same locality. Fig. 6, individual showing posterior adductor muscle scar and part of pallial line, x 1.0, same locality. Figures 7-24. Corbula basiniformU n. sp Page 130 Abundant, Weno shale and ironstone. Cooke and Grayson counties, Texas and southern Oklahoma. Fig. 21, type individual, x 1.5; locality: 604, near Den- ison, Texas. Other individuals, x 1.5, same locality. University of Texas Bulletin No. 1856 Plate 9 20 PLATE 10 Corbula, Area, Protocardia, Neritina, Nerita, Natica, Lunatia, Trochus, Anchura, Cinulia, Globiconcha, Turritella 168 University of Texas Bulletin PLATE 10. Corbula, Nucula, Area, Protocardia; Neritina, Nerita, Natica, Lunatia, Plate 10 Trochus, Anchura, Cinulia, Globiconcha, Turritella Figures 1-4. Corbula wenoeiuU n. sp Page 127 Weno shale, rare. Fig. 4, type. All individuals x 1.5. Locality: 601, pit of brickyards, one and three-fourths miles southeast of Gainesville, Texas. Figure 5. Corbula littoralis n. sp : Page 133 Weno shale, rare. Fig. 5, type individual, x 1.5. Locality: 601, pit of brick- yards, one and three-fourths miles southeast of Gainesville, Texas. Figure 6. Area wasbitaensi* n. sp Page 121 Abundant, Pawpaw clay; rare, Grayson, Den ton and Duck Creek formations, clay facies and more rare in the marl facies. Fig. 6, type individual, x 1.5. Locality: 714, one-fourth mile south of the International and Great Northern Railway bridge across Sycamore Creek, near Fort Worth, Texas, at the base of the Pawpaw clay. Figures 7-9. Corbula basiniformis n. sp Page 130 Abundant, Weno shale. Locality: 604, cut of St. Louis and San Francisco Rail- way, one mile north of Union Station, Denison, Texas. (See PI. 9, figs. 7-24.) x 1.5. Figures 10111. Nucula wenoentis n. sp Page 120 Rare, Weno shale. Fig. 10, type individual, x 1.5. Fig. 11, x 1.5. Locality: 601, pit of brickyards, one and three-fourths miles southeast of Gainesville, Texas. Figures 12-16, 19-20. Nucula nokonu n. sp Page 118 Occasional, Weno shale, x 1.5. Locality: 604, near Denison, Texas. Type, Fig. 19, x 1.5, same locality. Figures 21-26, 32. Protocardia sp. aff. multistriata (Shumard) Page 126 Abundant, Weno ironstone and shale, x 1. Locality: 601, near Gainesville, Texas. Figure 27. Neritina sp Page 139 Rare, middle Weno shale (buff marl). Locality: 601, near Gainesville, Texas. xl.5. Figure 28. Nerita sp Page 139 Rare, middle Weno shale. Locality: 601, near Gainesville, Texas, x 1.5. Figure 29. Natica sp Page 140 Rare, ironstone and upper Weno shale. Locality: 601, near Gainesville, Texas. Weno and Pawpaw Formations 169 Figures 30-31. Trochu* laticonicut n. sp. . Page 138 Rare, middle Weno shale (buff marl). Locality: 601, near Gainesville, Texas. Fig. 30, type individual, x 1.6. Fig. 31, x 1.5. Figures 33-37. Cinulia washitaensii n. sp Page 143 Occasional, middle and upper Weno shale. Locality: 601, near Gainesville, Texas. Fig. 33, type individual, x l.B. Figs. 34-37, x 1.5. Figure 38. Lunatia sp Page 140 Rare, Weno ironstone and upper Weno shale. Locality: 601, near Gainesville, Texas. x 1.5. Figures 39-40. Ancjiura mudgeana White Page 139 Abundant, middle and upper Weno shale, Cooke and Grayson counties, Texas. Locality: 604, near Denison, Texas, x 1.5. Figure 41. Globiconcha sp Page 140 Rare, Weno ironstone. Locality: 601, near Gainesville, Texas, x 1.5. Figure 42. Turritella worthensis n. sp Page 142 Abundant, lower Weno marl, Tarrant County, Texas. Type. Locality, 618, near Fort Worth, Texas. Fig. 42, type invidual, x 1.5. Figure 43. Turritella grayioneniis n. sp Page 140 Abundant, Weno shale, Grayson County, Texas; occasional, Cooke County, Texas. Locality: 604, near Denison, Texas. Type, Fig. 43, x 1.5. University of Texas Bulletin No. 1856 Plate 10 39 PLATE 11 Pecten, Epiaster, Nodosaria, Ancycloceras 172 University of Texas Bulletin PLATE 11. Pecten, Epiaster, Nodosaria, Ancycloceras. Plate 11 Figure 1. Ancycloceras bendirei n. sp Page 70 Rare, Weno formation, base, marl facies. Fig. 4, type individual, x 1.2. Locality: 618, near Fort Worth, Texas. Figure 2. Nodosaria texana Conrad Paije 145 Abundant as isolated individuals and rarely in slabs, upper third of Weno and base of Pawpaw formations in north central Texas; abundant in flag layers, upper and to a less extent the middle Del Rio clay in West Texas. Fig. 3, x 5.0. Locality: Terlingua, Texas. (Compare Univ. Texas Bull 1945, pi. 21.) Figure 3. Epiaster subobesus n. sp Paga 110 Occasional, Weno formation, marl facies, and Pawpaw formation, marl facies. Abundant near base of Weno, in the "first terrace" of the Fort Worth region. Fig. 2. Locality: 618, near Fort Worth, Texas, type individual, x 1.0. Figure 4. Pecten inconspicuus Cragin Page 12.3 Abundant, Weno shales and ironstone; rare, Denton clay; rare, Pawpaw forma- tion, sand and ironstone facies. Cooke and Grayson counties, Texas, and southern Oklahoma. Fig. 1, clay-ironstone shell conglomerate from the middle Weno shales, x 4.0. Locality: 604, near Denison, Texas. University of Texas Bulletin No. 1856 • . .' On A New Ammonite Fauna of the Lower Turonian of Mexico BY Emil Bbse 176 University of Texas Bidletin Exogyra Say 230 Exogyra haarmanni sp. nov 230 Exogyra of r. olisiponensis Sharpe 230 GASTROPODA 232 Tylottoma Sharpe 232 Tylostoma aff . ovatum Sharpe 232 • ECHINODERMATA 232 Hemiaster Desor 232 Hemiaster sp 232 LIST OF ILLUSTRATIONS FIGURES Figure 1. Metoecocerai aff. white! Hyatt, suture 204 Figure 2. Suture, Vatcocera* angermanni «i. sp. (above) and Vascocerat aff. adonense Choffat (below) 216 Figure 3. Suture, Va.cocera. aff. gamai Choffat 21G Figure 4. Sutures, Vascocera* mohovanenie n. sp. (above) , and Mammite* mohovaensi* n. sp. (below) 220 Figure 5. Suture, Neoptychite* aff. cephalotu* Courtiller 222 Figure 6. Suture, Neoptychite* aff. cephalotu.- Courtiller 222 Figure 7. Sutures, Neoptychite* aff. xetriformU Pervinquiere (lower left hand corner) and Hoplitoide* sp. (other three) 226 PLATES Plates 12-20. Lower Turonian Fossils from Cerro del Macho.. ..235-252 ON A NEW AMMONITE FAUNA OF THE LOWER TURONIAN OF MEXICO BY EMIL BOSE I INTRODUCTION A number of years ago the existence of Turonian beds was proven in Mexico and later on it was shown that these beds have a great distribu- tion in the country. At first very few localities with faunas of this age were known, but later the finds of fossils of Turonian age have augmented in such a manner that we now know that the Turonian has a vast dis- tribution in Mexico, numerous localities having been discovered between Lat. 20°30' N. and Lat. 32° N. All of these beds are petrographically very uniform and consist of argillaceous shales and laminated limestones with intercalations of thin beds of limestone, all of black to light gray color. The fauna of these beds is also rather uniform and consists mostly of numerous specimens of Inoceramus labiatus Schlotheim, in some places accompanied by Inoceramus hercynicus Petraschek ; in some localities fishes are relatively numerous ; in others bivalves other than Inoceramus are found. Cephalopods have been found very rarely, all of them crushed and nearly indeterminable. The determination of the age had to be founded exclusively on the Inoceramus and on the position of the beds in relation to the Senonian and the Cenomanian. About nine years ago I received the first collections of Turonian am- monites, which allowed a much better determination of the age of the beds mentioned here because these cephalopods were found together with well preserved specimens of the same Inoceramus which already had been determined by us as 1. labiatus. In February, 1911, Dr. Ernst Angermann sent me a email collection of fossils collected by him on the Cerro del Macho, Hacienda del Moh6vano, Municipality of San Pedro, District of Parras in the State of Coahuila. The greater part of these fossils consisted of internal molds of bivalves and gastropods, but there were also present three cephalopods relatively badly preserved and several indeterminable fragments of ammonites. I recognized at once that these fossils belonged to a facies and a horizon altogether unknown in Mexico, one of the ammonites being a Vascoceras of the group of V. Kossmati and another a Neoptychites of the group of N. xetriformis Pervinquiere, the bivalves belonged mostly to Trigoniu, 180 University of Texas Bulletin Avicula of the group of A. gravida Coquand, the gastropods to Tylostoma and similar genera. A short time afterwards I showed these fossils to Dr. E. Haarmann, geologist of the Cia. Perforadora Mexicana, who then told me that he had a much larger collection of fossils from the same locality which he had made before Dr. Angermann had visited the place ; and he offered me his material for a detailed paleontological study. The collection of Dr. Haar- mann proved to be much larger than that of Dr. Angermann and con- tained a large number of ammonites some of which were rather well preserved. Haarmann in making his collection had separated the fos- sils of the different beds. The lowest of these beds was represented by a single piece of rock with impressions of bivalves, but as this rock had a very distinct character from that of the other beds and as in a locality of apparently the same age a badly preserved sea urchin had been found which appeared to belong to Hemiaster, I asked Dr. Haarmann to collect better material in the lowest horizon, because this horizon seemed to be- long to the Cenomanian. Haarmann visited the locality again in August, 1911, collected ammonites in each of the three beds distinguished by him, and turned this material over to me in April, 1912. The material thus collected proved to be of great stratigraphical and paleontological interest, as will be shown by the following description. But before I enter into a detailed study I wish to express my gratitude to Dr. E. Haarmann to whose amiability I owe the opportunity of studying this interesting fauna. I also wish to express my obligations to Professor Dr. W. Branca in Berlin who kindly sent me a great number of photo- graphs of Turonian ammonites from Egypt, studied by Dr. Eck but at that time still undescribed. LIST OF LITERATURE CITED IN THIS PAPER 1. Boule, Lemoine et Thevenin, Diego Suarez. — M. Boule, P. Lemoine et A. Thevenin, Paleontologie de Madagascar. Cephalopodes cretaces des environs de Diego- Suarez. — Ann. de Palontologie t. I et II, Paris, 1906-07. 2. Choffat, Especes nouv. ou peu conn. — P. Choffat, Recueil d'etudes paleontologiques sur la faune cretacique du Portugal. Vol. L, Especes nouvelles ou peu connues. Ire. serie. Section des Travaux geologiques du Portugal. Lisbon, 1886. 3. Choffat, Syst. cret. Portugal II. — P. Choffat, Recueil de Monographies strati- graphiques sur le systeme cretacique superieur au nord du Tage. Service geol. du Portugal. Lisbonne, 1900. 4. Chudeau, Ammonites du Damergou. — R. Chudeau, Ammonites du Damergou (Sahara meridional). — Bull. Soc. geol. France, 4me ser., t. 9, fasc. 1-2, 1909. 5. Coquand, Geol. et Pal. de Constantine. — H. Coquand. Geologic et Paleontologie de la region sud de la Province de Constantine. Mem. Soc. d'Emulation de la Provence, II. Marseille, 1862. A New Ammonite Fauna of the Lower Turanian of Mexico 181 6. Cotteau, Peron et Gauthier, Ech. foss. de 1'Algerie. — Cotteau, Peron et Gauthier, Echinides fossiles de 1'Algerie. Description des especes deja recueillies das ce pays et considerations sur leur position stratigraphique. IV, Etage Ceno- manien. Paris, 1878. 7. Eck, Turon in Aegypten. — O. Eck, Vorlaufige Mitteilungen tiber die Bearbeitung der Cephalopoden der Schweinfurthschen Sammlung und Uber die Entwick- lung des Turons in Aegypten. Monatsber. d. Deutsch. Geol. Ges. 1910. Ber- lin, 1911. 8. Fourtau, Faune cret. d'Egypte. — R. Fourtau, Contribution a 1'etude de la faune cretacique d'Egypte. Bull. Institut Egyptien, ser. 4, vol. 4, 1903. 9. Fritsch, Ceph. bohm. Kreideform. — A. Fritsch, Cephalopoden der bohmischen Kreideformation (unter Mitwirkung des Dr. Urb, Schlonbach). Prag, 1872. 10. Geinitz, Elbthalgebirge. — H. Br. Geinitz, Das Elbthalgebirge in Sachsen. Pala- eontographia Bd. 20, I u. II. 1872-75. 12. Gueranger, Album Paleontol. — Ed. Gueranger, Album Paleontologique de la Sarthe representant au moyen de la photographic les fossiles recueillis dans cette circinscription. Le Mans, 1867. 13. Guillemain und Harbort, Profil d. Kreidesch. a. Mungo. — C. Guillemain und E Harbort, Profil der Kreideschichten am Mungo. Abh. d. k. Preuss. Geol. Landesanstalt Neu Folge, Heft 62, 1909. 14. Haug, Traite de Geologic. Paris, 1908-11. 16. Hyatt, Pseudocer. — A. Hyatt, Pseudoceratites of the Cretaceous. Edited by T. W. Stanton. U. S. Geol. Surv. Monogr. vol. 44, Washington, 1903. 16. Jack and Etheridge, Queensland.— R. L. Jack and R. Etheridge, Jr. The Geology and Paleontology of Queensland and New Guinea. Brisbane and London 1892. 17. v. Koenen, Nachter. Foss. Mungo in Kamerun. — A. von Koenen, Nachtrag zu Ueber Fossilien der Unteren Kreide am Ufer des Mungo in Kamerun. Abh. K. Ges. d. Wiss. zu Gottingen, Math. Phys. Kl. Neue Folge, Bd. 1, No. 1 1898. 18. Kossmat, Stidind. Kreideform. — Fr. Kossmat, Untersuchungen uber die sudin- dische Kreideformation. Beitrage zur Palaeontologie und Geologie Oester- reich-Ungarns und des Orients, I Bd. 9, 1895; II u. Ill Bd. 11, 1897. 19. Lartet, Geol. de la Palestine.— L. Lartet, Essai sur la geologie de la Palestine et des contrees avoisinantes telles que 1'figypte et PArabie. II me partie Paleontologie. Ann. d. Sciences Geologiques publ. s. 1. dir. de M. Hebert et A. Milne-Edwards. T. III. Paris, 1872. 20. Laube und Bruder, Amm. d. bohm. Kreide.— G. C. Laube und G. Bruder, Ammo- nites der bohmischen Kreide. Palaeontographica Bd. 33, 1887. 21. Lisson, Amm. del Peru. — C. I. Lisson, Contribucion al conocimiento sobre algunos Ammonites del Peru. 4o Congreso cientifico Latino-Americano, lo Panamer- icano, celebrado en Santiago de Chile. Lime, 1908. 22. Lisson, Terr, recon. en el Peru.— C. I. Lisson, Terrenes reconocidos hasta hoy en el Peru y sinopsis de su fauna y flora fosiles. Bol. de Minas, Ind. y Constr publ. por la Escuela de Ingenieros, ser. II, t. IV. Lima, 1912. 23. Peron, Amm. du Cret. sup. de 1'Algerie. — A Peron, Les ammonites du Cretace superieur de 1'Algerie. Mem. Soc. geol. France, Paleontologie, t. 6 et 7 mem. no. 17. 1896-97. 24. Pervinquiere, fit. geol. Tunisie.— L. Pervinquiere, Etude geologique de la Tunisie 182 University of Texas Bulletin Centrale. Theses presentees a la Faculte des Sciences de Paris p. obt. le grade de Docteur-es-Sciences Naturellea. Paris, 1903. 25. Pervinquiere, Paleontologie Tunisienne. — L. Pervinquiere, fitudes de Paleontologie Tunisienne. I Cephalopodes des Terrains Secondaires. Dir. Gen. des Travaux Publics, Carte geol. de la Tunisie. Paris, 1907. 26. Petrascheck, Amm. d. sachs. Kreideform. — W. Petrascheck, Die Ammoniten der sachsischen Kreideformation. Beitr. z. Pal. u. Geol. Oesterreich-Ungarns u. d Orients. Bd. 14, 1902. 27. Petrascheck, Inoc. a. d. Kr. Bohmens. — W. Petrascheck, Ueber Inoceramen aus der Kreide Bohmens und Sachsens. Jahrb. d. K. K. Geol. Keichsanstalt. Wien Bd. 53, 1903 (1904). 28. Roemer, Kreidebild. v. Texas. — F. Roemer, Die Kreidebildungen von Texas und ihre organischen Einschliisse. Bonn, 1852. 29. Schlagintweit, Vracon u. Cenoman in Peru. — 0. Schlagintweit, Die Fauna des Vracon und Cenoman in Peru. N. Jahrb. f. Min., Geol. u. Pal., Beilagebd. 33, 1912. 30. Sharpe, Secondary distr. of Portugal. — D. Sharpe, On the Secondary District of Portugal which lies on the North of the Tagus. Quart. Jour. Geol. Soc London, Vol. VI, 1850. 31. Sharpe, On Tylostoma. — D. Sharpe, On Tylostoma, a proposed genus of Gaste- ropodous Mollusks. Quart. Jour. Geol. Soc. London, Vol. 4, 1849. 32. Solger, Mungokreide. — Fr. Solger, Die Fossilien der Mungokreide von Kamerun und ihre geologische Bedeutung, mit besonderer Beriicksichtigung der Am moniten. Beitrage zur Geologic von Kamerun herausgeg. v. E. Esch. Stutt- gart, 1904. 33. Stanton, Colorado Form.- — T. W. Stanton, The Colorado Formation and its in- vertebrate Fauna. U. S. Geol. Surv. Bull. No. 16, 1893. 34. Stoliczka, Ceph. Cret. Rocks India. — F. Stoliczka, The fossil cephalopoda of the Cretaceous Rocks of Southern India (Ammonitidae). Mem. of the Geolog- ical Surv. of India. Palaeontologia Indica, 1865. 35. Thomas et Peron, Hauts-Plateaux de la Tunisie. — Ph. Thomas et A. Peron Description des mollusques fossiles des Terrains Cretaces de la region sud des Hautes — Plateaux de la Tunisie recueillis en 1885 et 1886. Exploration Scientifique de la Tunisie. Paris, 1889-90. 36. White, Inv. foss. Nevada, Utah, etc. — Ch. A. White, Report upon the inverte- brate fossils collected in portions of Nevada, Utah, Colorado, New Mexico, and Arizona, by parties of the expeditions of 1871, 1872, 1873 and 1874. Report upon Geogr. and Geol. Expl. and Surv. west of the 100th Meridian by Geo. A. Wheeler. Eng. Dept. U. S. Army, Part IV Palaeontology. Wash- ington, 1875. 37. White, Brazil. — Ch. A. White, Contributes a Paleontologia do Brazil. Archives do Museu Nacional do Rio de Jeneiro, Vol. VII, 1887. 38. Woods, Cret. dep. Northern Nigeria. — H. Woods, The palaeontology of the upper Cretaceous deposits of Northern Nigeria. The Geology and Geography of Northern Nigeria by J. D. Falconer. London and Bungay, 1911. 39. Yabe, Cret. Ceph. Hokkaido II. — H. Yabe, Cretaceous Cephalopoda from the Hokkaido. Part II. Jour, of the College of Science, Imp. Univ., Tokyo, 1904, Vol. 20, art. 2. A New Ammonite Fauna of the Lower Turanian of Mexico 183 40. Yabe, Strat, u. Pal. Hokkaido.— H. Yabe, Zur Stratigraphie und Palaontologie der oberen Kreide von Hokkaido und Sachalin. Zeitschr. d. Deutsch. geol. Ges. Bd. 61, 1909. 41. Zittel, Lib. Wiiste. — K. A. Zittcl, Beitrage zur Geologie und Palaeontologie der Libyschen Wiiste und der angrenzenden Gebiete von Aegypten. I. Geolo- gischer Theil. Palaeontographica Bd. 30, I. 1883. STRATIGRAPHY The Cerro del Macho is a small hill in the eastern part of the Hacienda del Mohovano belonging to Mr. Frederick Ritter. The hacienda lies to the southeast of the station Carillo of the railway which connects Sierra Mo- jada, Coahuila with Escalon, Chihuahua (Mexican Central Railway) and part of its land belongs to the State of Chihuahua while the rest lies in the State of Coahuila. The Cerro del Macho belongs to this last region and lies near the boundary line of both states. Dr. E. Haarmann gave me the following geological cross-section of the fossiliferous locality, to which I add the stratigraphical explanation ob- tained as the result of the study of the fauna. -JT Fig. 1 Fossil bearing beds on the Cerro del Macho, Hacienda del Moh6vano, Coahuila. III. Gray hard limestones "1 II. Gray-bluish marls J I. Yellow and red marls and argillaceous limestones Upper Cenoman- Lower Turonian. Three different petrographical horizons can be distinguished : the low est beds consist of yellow and red marls with argillaceous limestones con- taining numerous fossils, especially bivalves; this horizon which for the present we shall designate with the number I has a thickness of only two 184 University of Texas Bulletin meters in this locality, but its base is covered. Above these marls lie gray- bluish marls with large cephalopods ; the thickness of this horizon which we designate as Number II, is 2.5 meters. On top of these marls we find gray limestones with numerous cephalopods, bivalves and gastropods ; the thickness of this horizon, which we call Number III, is about 5 to 6 meters, its upper limit being unknown. According to Dr. Haarmann the beds show a strike of N50-60°E and a dip of approximately 10°NW.1 The whole outcrop has thus only a thickness of about 10 meters, but nevertheless we find two different horizons, as will be shown in the following. Among the fossils collected in this locality I have been able to distinguish twenty-one different species which are distributed in the three horizons in the following manner : Horizon I. Metoecoceras aff. Whitei Hyatt Metoecoceras n. sp. Exogyra Haarmanni n. sp. Exogyra cfr. olisiponensis Sharpe Hemiaster sp. Horizon II. Mammites mohovanensis n. sp. Pseudaspidoceras aff. Footeanum Petrascheck Pseudaspidoceras aff. pedroanum White Vascoceras aff. Adonense Choffat Fagesia Haarmanni n. sp. Fagesia Pervinquieri n. sp. Horizon III. Vascoceras Angermanni n. sp. Vascoceras ex. aff. Gamai Choffat Vascoceras (?) sp. Vascoceras mohovanense n. sp. Neoptychites aff. xetriformis Pervinquiere Hoplitoides aff. mirabilis Pervinquiere Inoceramus labiatus Schlotheim Avicula Aguilerae n. sp. Trigonia sp. Crassatella sp. Tylostoma aff. ovatum Sharpe To show the stratigraphic importance of the different species we shall have to compare them with related forms. iAccording to a sketch of Dr. Angermann the strike of the beds i3 N-S and the dip 10 degrees W. A New Ammonite fauna of the Lower Turanian of Mexico 185 Horizon I. Upper Cenomanian Turonian Species from Cerro del Macho Related species Metoecoceras aff. Whitei Hyatt M. Whitei Hyatt ? T Metoecoceras n. sp. M. Geslianum Petrascheck + Exogyra Haarmanni n. sp. Exogyra cfr. olisiponensis Sharps Ex. olisiponensis Sharpe + + Hemiaster sp. The age of this horizon cannot be determined quite exactly. The fossils are few, the cephalopods among them indicate only that the horizon belongs either to the lower Turonian or the upper Cenomanian. Metoecoceras aff. Whitei is similar to forms found in the Colorado Formation of the United States, a division which up to now has not been subdivided stratigraphic- ally with the necessary exactness ; it probably represents in its larger part the Turonian, but may possibly contain some upper Cenomanian and a por- tion of Emscherian. The portion in which M. Whitei has been found be- longs to the lower part of the formation, which is either the lower Turonian or the upper Cenomanian. Our Metoecoceras n. sp. is very similar to M. Geslianum Petrascheck,1 which occurs in the upper Cenomanian of Saxony, but we do not know exactly if our specimen has been found in this lowest horizon or in one a little higher. Interesting is the occurrence of an Exogyra certainly belonging to the group of Exogyra olisiponensis Sharpe. This species is found on the bor- der of the Mediterranean in the Cenomanian as well as in the Turonian, although the variety which is most similar to our specimen seems to be limited principally to the Cenomanian. Our Exogyra Haarmanni n. sp. is a new species and not very characteristic, therefore without any strati- graphic value. The Hemiaster found in the same bed can not be used for the determination of the age as it does not appear to be identical with any described species nor to be closely related to any known species which might indicate the age of these beds. The small number of fossils of this horizon does not allow an exact de- termination of its age. Taking into consideration the radical difference be- tween the character of this fauna and that of Horizon II, and the presence of a form of Metoecoceras very similar to the one of the upper Cenomanian of Saxony, I feel inclined to consider this horizon provisionally as upper Cenomanian until other and more characteristic fossils allow a more exact determination of the age. Much more numerous is the fauna of Cephalopods in Horizon II and iPetrascheck. Amm. d. sachs. Kreideform., 1.140 (10) pi. 7 (1) ; figs. 3-5. 186 University of Texas Bulletin their forms are so characteristic that they easily allow the determination of the age of these beds. In the following table we shall compare them with related species of other countries. Horizon II. Turonian Species from Cerro del Macho Related species Lower Middle Mammites mohovanensis n. sp. M. nodosoides Schlotheim Pseudaspidoceras aff. Footeanum P. Footeanum Petrascheck + Pseudaspidoceras aff. pedroanum P. Footeanum Stoliczka + Vascoceras aff. adonense V. adonense Choffat + Fagesia Haarmanni n. sp. F. superstes Kossmat + Fagesia Pervinquieri n. sp. F. tevesthensis Peron + All the species of this horizon indicate that it belongs to the lower Tu- ronian or Salmurian. It s true that Choffat cites his Vascoceras adon- ense from the middle Turonian, but I believe that this middle Turonian of Portugal belongs in reality still to the Salmurian, i.e., the lower Turonian. The occurrence of forms belonging to the groups of Fagesia superstes, Fa- gesia tevesthensis, Mammites nodosoides, Inoceramus labiatus, etc., ap- pears to be quite decisive for the determination of the age of those beds. In our own case we have to consider that this horizon lies immediately above what we take to be upper Cenomanian ; there seems to be no reason to doubt that our Horizon II represents the very lowest Turonian. This idea is confirmed also by the fauna of Horizon III, which will be discussed farther on. Our Mammites mohovanensis is very nearly related to M. nodosoides Schlotheim. It differs principally in its broader cross section; still more similar to our species is Mammites conciliatus Stoliczka, which belongs to the same group, the main difference consisting in its more evolute form and some details of ornamentation. In these details our form is still more similar to a form determined by Fritsch as Mammites conciliatus which in reality occupies an intermediate position between our species and that of India. The species which we have called Pseudaspidoceras aff. Footeanum Pe- trascheck is much less related to the type of this group (P. Footeanum Stoliczka) than to the specimens from the lower Turonian of Saxony de- scribed by Petrascheck, on account of the more rounded and less subquad- rangular cross section, as well as the greater height of the whorl. This dif- ference may be explained in our section by its large size; comparing the different figured forms of P. Footeanum we see that the adult specimens tend to lose their quadrangular cross section. This group has been found A New Ammonite Fauna of the Lower Turanian of Mexico 187 in the lower Turonian in many cases where an exact determination of the age of the beds has been possible. Varieties of this group have be.en de- scribed from India, from different parts of northern Africa, as Egypt1 and Tunis- ; from Portugal3, from Nigeria4, from Saxony"', and from Bra- zil." It is therefore a universally distributed form which characterizes the lower Turonian. To the same group of Pseudaspidoceras Footeanum belongs also the species called by me Pseudaspidoceras an*, pedroanum White. It is still nearer related to the Indian type than the former species, but differs by its less strong ribs and the smooth ventral part. In all its characters it is similar to the Ammonites pedroanus White and only differs in some de- tails of the ornamentation. The similarity is so great that I have not been able to separate the two forms specifically and have not united our speci- men with the Brazilian species only because this latter form is still imper- fectly known. ' . Our Vascoreras aff. adonense is certainly very similar to the Portuguese type from the Turonian, but differs by its suture and the form which is still more evolute. The form of greatest stratigraphic interest in our fauna is perhaps our Fagesia Haarmanni n. sp. It belongs to the group of Fagesia superstes Kossmat, but differs from the type as well as from all the other species of this genus by its more evolute form. The species belonging to this group are limited to the Turonian and especially to the lower part of it. The type was described from the Utatur group of India,7 and a very typical form has also been found in Tunis8 ; a nearly related species has been cited from the Turonian of Portugal.0 Fagesia Pervinqieri n. sp. is a very characteristic species and belongs to that group of Fagesia which loses its ribs in a rather juvenile state of growth ; the type of this group is Fagesia tevesthensis Peron. Our species differs from the type by its higher and less broad whorls. According to Pervinquiere Fagesia Rudra Stoliczka10 belongs also to this group; this •Zittel, Lib. Wuste, p. LXXIX (A. cfr. Footeanus) Eck, Turon in Acgypttn. p. 3^0 (Acanthoceras cfr. Footeanum). 2Pervinquiere. Paleontologie Tunisienne, p. 314 (Mammites Salmuriensi*) . 'Choffat, Especes nouv. ou peu conn., p. 66 (Acanthoceras cfr. Foolfanum', 4Woods, Cret. dep. Northern Nigeria, p. 283 (Mam-mites [Pseudaspidocerat] up.) ^Petrascheck, Amm. d. sachs. Kreideform., p. 144 (Mammites f "White, Brazil, p. 212 (Ammonites pedroanus). 'Kossmat, Sudindische Kreideform., p. 133, pi. 17, fig. 1. "Pervinquiere, Palecntologie Tunisienne, p. 322, pi. 20, fig. 1-3. »Choffat, Especes nouv. ou peu conn., p. 69, pi. 10, fig. 4. '"Stoliczka, Ceph. Cret. Rocks India, p. 122, pi. 60. 188 University of Texas Bulletin species which occurs in the Utatur group of India is similar to our species on account of the missing umbilical nodules in a stage of development which still shows the ribs on the ventral part; it differs, though, by its much broader and larger whorls. Another form which by Pervinquiere is considered as belonging to the same group is Ammonites Kotoi Yabe.1 Per- vinquiere believes that this species is perhaps identical with Fagesia teves- thensis Peron, but it appears to me that we have here a different species although it is certainly related to the African form. According to Yabe2 it is not quite certain from which beds this form has been collected ; it oc- curs either in the Mammites beds or in the Scaphites beds. The age of Fagesia Rudra is not well known, although Kossmat presumes that this species belongs to the middle Utatur group. Fagesia tevesthensis charac- terizes the lower Turonian ; a very similar form exists in beds of the same age in France and another in the Turonian of Portugal. Still richer than the fauna of Horizon II is that of the upper limestones which we have distinguished as Horizon III. For their comparison with related species we shall again unite them in a table. Lower Species from Cetro del Macho Related species Turonian Emscherian Vascocerat ' tigermanni n. sp. V. Kossmati Choffat + Vascocera*, ex aff. Gamai V. Gamai, Choffat + Vascoceras (?) sp. V. (?) arnesense Choffat + Vascoceras mohovanense n. sp. V. polymorphum Pervinquiere + Neoptychites aff. cephalotus N. cephalotus Courtiller + Neoptychites aff. xetriformis N. xetriformis Pervinquiere + Hoplitoides aff. mirabilis H. mirabilis Pervinquiere + Inoceramns labiatus Schlotheim /. labiatus Sch'otheim + Avicula Aguilerae n. sp. A. gravida Coquand + + Tylostoma aff. ovatum Sharpe T. ovatum Sharpe + (Cenomanian to upper Turonian Nearly all of the groups of ammonites cited in this list occur only in the lower Turonian, to which, according to my opinion, belong also the beds with Vascoceras of the so-called middle Turonian of Portugal. Vascoceras Angermanni n. sp. is very similar to V. Kossmati Choffat, but its form is still a little broader, there is no doubt that it belongs to the same group and this is until now only known in the Turonian of Portugal and the lower. Turonian of Egypt.3 The fossil which we have called Vascoceras ex. aff. Gamai Choffat is a juvenile form and not very well preserved which is very similar to the iYabe, Cret. Ceph. Hokkaido II, 26, pi. 6, figs. 3-4. 2Yabe, Strat. u. Pal. Hokkaido, p. 441. 3Eck, Turon in Tegypten, p. 381, 382. A New Ammonite Fauna of the Lower Turanian of Mexico 189 small individuals figured by Choffat1 in figures 3 and 4 of plate 7 and figure 2 of plate 10. Considering the size and state of preservation this specimen is not of great stratigraphic value. Vascoceras (?) sp. is a pretty large specimen which is very similar to Ammonites arnesensis Choffat. The generic determination is not quite certain as is also the case with A. arnesensis. Our specimen is a little twisted ; it does not have much importance for the determination of the age of the beds. Vascoceras mohovanense n. sp. is a specimen relatively small but very characteristic; it belongs certainly to the group of Vascoceras polymor- phum Pervinquiere of the lower Turonian of Tunis. It differs from the type by a missing intermediate row of nodules but in its general character and also in its suture is nearly related to the type. Pervinquiere considers Vascoceras subconciliatum Choffat from the Turonian of Portugal as a form of the same group but this species is different from ours on account of its general form and its suture. The species described by me as Neoptychites aff. cephalotus Courtiller is a juvenile specimen which resembles greatly the small individuals of the cited species, as has been demonstrated in the paleontological part of this paper. The group of Neoptychites cephalottts characterizes the lower Tu- ronian ; it occurs frequently in Algiers and Tunis, also in the neighborhood of Saumur, France. Similar and perhaps identical forms have been found in India (Neoptychites Telinga Stoliczka)2 and in Kamerun (Neoptychites Telingaeformis Solger3) ; the aee of the beds where these latter species have been found is not exactly known. The form which I compare with Neoptychites xetriformis Pervinouiere, is not very well preserved but resembles sufficiently the species from Tunis. Pervinquiere considers as a nearly related form Neoptychites crassus Sol- ger,4 the age of this latter species is not determined with certainty. In the limestones of Horizon III we find frequently cephalopods which resemble very much the bicarinated Hoplitoides of Pervinauiere. The greater part of these specimens is entirely corroded but in one I have been able to prepare a portion of the interior whorl which clearly shows the ex- istence of the two lateral keels on the ventral portion ; one also notes the suture in part, certainly much destroyed but showing the same elements as in the bicarinated Hoplitoides. A large specimen has the external form of 'Choffat, Especes nouv. cm peu conn. 2Stoliczka, Ceph. Cret. Rocks India, p. 125, pi. 62; Kossmat, Sudind. Kreideform., p. 71, pi. 7, fig. 1, pi. 17, fig. 13. 'Solger, Mungokreide, p. 108. 'Solger, Mungokreide, p. 119, pi. 3, fig. 5. 190 University of Texas Bulletin Hoplitoides mirabilis but is a little less involute. This group is of some in- terest in so far as having been found only in the lower and upper Turon- ian. The types of Hoplitoides mirabilis1 and H. Munieri2 occur in Tunis mainly in the lower Turonian, H. Munieri also in the upper Turonian. A similar species has been found also in the Turonian of Egypt.3 In the same Horizon III, Dr. E. Haarmann also collected four specimens of Inoceramus of which three are typical individuals of Inoceramus labia- tus Schlotheim. According to an observation made by Jose G. Aguilera, this fossil occurs in great numbers in beds north of the station of Carillo which apparently overlie limestones identical with those described here. In Horizon III occurs very frequently Avicula Aguilerae n. sp. This species is very similar to Avicula- gravida Coquand which occurs in north- ern Africa in the Turonian as well as in the lower Senonian or Emscherian. The form and size of this Avicula are so similar to those of ours that this find in Mexico has a certain stratigraphic interest. In the material of Horizon III we find a great number of other bivalves, but all in the state of internal molds ; a specific determination is entirely impossible. The most frequent form probably belongs to Tylostoma or some subgenus of Natica; the greater part of the material is badly pre- served, but some specimens are a little more complete, although preserved as internal molds, and resemble strongly Tylostoma ovatum Sharpe which in Portugal occurs in beds from the Cenomanian to the upper Turonian. From the character of the fauna of Horizon III we have to conclude that these beds still belong to the lower Turonian. This appears rather proba- ble from the circumstance that Horizon II is extremely thin and is well confirmed especially by the cephalopod fauna. Interesting is the occur- rence of Inoceramus labiatus Scholtheim. This fossil is extremely common in Mexico and generally is found in great numbers in calcareous shales and shaly limestones. The question now is, what relation exists between those beds and those of Cerro del Macho? In the described locality the shales, etc., do not exist, but according to the identification of J. G. Aguil- era these are found north of the station of Carillo where they apparently overlie limestones similar to those of the Cerro del Macho. If we accept this explanation, our beds at Cerro del Macho have to be considered as the lowest part of the Turonian, while the shales with Inoceramus labiatus would be a little younger and perhaps represent the lower as well as the upper Turonian. We have no data with which to solve this problem, as up to now the beds with Inoceramus labiatus have not been found in contact 1Pervinquiere, Paleontologie Tunisienne, p. 218, pi. 10, fig. 3. 2Idem, ibid., p. 217, pi. 10, figs. 1, 2. 3Eck, Turon in Aegypten, p. 380, 386. A New Ammonite Fauna of the Lower Turanian of Mexico 191 with the cephalopod beds described here ; neither have those beds with Ino- ceramus labiatus been found in immediate contact with fossiliferous beds of the Emscherian. Only in one place, Opal, Zacatecas, I have found beds with Inoceramus labiatus (rare) and /. hercymicus (very frequent) in contact with sandstones containing an Inoceramus nearly related to Inoce- ramus cycloides, but the cross section of this locality is too incomplete and the fauna too poor for a decision of this rather important problem. The locality of Cerro del Macho is stratigraphically important in so far as it gives us some data for the limitation of the upper Cenomanian and the lower Turonian. In a former work we have been able to subdivide the Cenomanian of Cerro de Muleros near Ciudad Juarez, but we have not been able to find fossils in the sandstones between the beds with Inoceramus labiatus and the marls with Hemiaster'Calvini; thus it was impossible to decide if those sandstones belonged to the Cenomanian or the Turonian. In the present case we have very fossiliferous beds very near the limit be- tween the Cenomanian and the Turonian. The fossils of the Cenomanian are very different from those found up to the present in Cenomanian rocks of Mexico. Of especial importance is the occurrence of Metoecoceras. The Turonian ammonite fauna is also entirely new for Mexico, the few ammonites so far found in the beds with Inoceramus labiatus belonging to entirely different groups. Haarmann has distinguished two horizons, II and III, but these do not appear to be more than local subdivisions notwithstanding the circum- stance that the fauna of the two beds seem to be rather different. We must not give too much importance to this circumstance, as the collections so far made are still rather small and the aspect of the fauna may change alto- gether with larger collections made. As far as we can see, the lower bed contains principally cephalopods while in the upper one bivalves and gas- tropods predominate. With respect to the conditions of life in this locality we may say with some certainty that at the end of the CeYiomanian in the Cerro del Macho region as well as in others of northern Mexico, especially in the State of Chihuahua, there existed a littoral facies or at least a very shallow sea; this is indicated by the great quantity of Ostreidae which nearly form beds or which have been carried away from neighboring beds. At the begin- ning of the Turonian age the sea seems to have deepened a little, the pre- dominance of the ammonites and the absence of littoral bivalves indicating a less shallow sea. It is probable that during the time of the deposition of the upper part of the Salmurian the sea again became a little shallower; this is indicated by the predominance of Lamellibranchia and Gastropoda with thick shells, but the facies is not quite as much a littoral one as in 192 University of Texas Bulletin Cerro del Muleros near Ciudad Juarez at the same time, where the corre- sponding beds consist entirely of sandstones. According to the observations of Haarmann and our palaeontological studies the stratigraphical cross section of the Cerro del Macho presents the following features : 5-6 m. of gray limestones with: Vascoceras Angermanni n. sp., V. ex aff. Gamai Choffat, Vase, sp., V. mohovanense n. sp., Neoptycliites aff. cepha- lotus Courtiller, N. aff. xetriformis Pervinquiere, Hopli- toides aff. mirabilis Pervinquiere, Inoceramus labiatt1? Schlotheim, Avicula Aguilerae n. sp., Tngonia sp., Cras- satella sp., Tylostoma aff. ovatum Sharpe, (Lamellibran- chia and Gastropoda extremely frr-quentj^ Hor. Ill Lower Turonian (Salmurian) 2.5 m. of gray-bluish marls with: Mammites mohovanensis n. sp., Pseudaspidoceras arf Footeanum Petrascheck, Ps. aff. pedroanum White, Vasco- ceras aff. adonense Choffat, Fagesia Haarmanni n. sp F. Perviniquieri n. sp. Hor. II 2 m. yellow and reddish marls and limestones with: Metoecoceras aff. Whitei Hyatt, Meto?.co-;eras nov. sp., Exogyra Haarmanvi n. sp., Ex. cfr. disiponensis Sharpe Hemiaster sp. (Lamellibranchia predominate). Hor. I Upper Cenomanian If really the beds with Inoceramus labiatus lie immediately on top of the cephalopod beds, as the observations of J. G. Aguilera seem to indicate, another deepening of the sea may have followed and the general rising of the bottom of the ocean did not begin before the age of the lower Se- nonian. ON THE RELATIONS BETWEEN THE FAUNA OF CERRO DEL MACHO AND ISOCHRONOUS FAUNAS OF OTHER REGIONS OF THE EARTH The fauna of the upper Cenomanian of Cerro del Macho is too small to be compared with others ; the most important fossil, Metoecoceras n. sp. belongs to a group which has been found in the upper Cenomanian. Of certain interest is the occurrence of Exogyra cfr. olisiponensis Sharpe be- cause it indicates a faunistic similarity with the development of the Ceno- manian along the border of the Mediterranean, a circumstance which to a certain degree can be noted also in the fauna of other Cenomanian beds of Mexico. A New Ammonite Fauna of the Lower Turanian of Mexico 193 I The fossils of the lower Turonian or Salmurian of the Cerro del Macho present a much better material for faunistic comparisons. Already while comparing our species with related ones from other regions we have seen that similar forms are found mainly around the Mediterranean, inclusive of Portugal. Comparing the faunas of the Salmurian in the above men- tioned region, we find that all of them contain certain elements which either do not exist in most other regions or which occur only very rarely there. We shall see later on that this special fauna is not restricted to the Mediterranean but extends also to other parts of Africa and that certain elements belonging to it occur also in Asia and America. This indicates a large extension of the same horizon, but1 at the present time it is impossible to say if this distribution coincides with that of the same paleontological facies. But before we enter into such a discussion we must compare our fauna with the isochronous faunas of the Mediterranean and other parts of the earth in a somewhat more detailed manner. Portugal: We begin with the region of Portugal. According to Choffat1 we find in the lower part of the Turonian (beds with Ostrea columba major) the following cephalopods: Puzosia cfr. planulata Sowerby Vascoceras Mundae Choffat Vascoceras Gamai Choffat Pseudaspidoceras cfr. Footeanum Stoliczka Neolobites sp. nov. In his middle Turonian we find the following species: Vascoceras Gamai Choffat Vascoceras Gamai Choffat var. triangularis Choffat Vascoceras Mundae Choffat Vascoceras amieirense Choffat Vascoceras silvanense Choffat Vascoceras adonense Choffat Vascoceras Grossouvrei Choffat Vascoceras Barcoicense Choffat Vascoceras Douvillei Choffat Vascoceras subconciliatum Choffat Vascoceras harttiforme Choffat Vascoceras Kossmati Choffat Vascoceras ( ?) arnesense Choffat iChoffat, Syst. cret. Portugal II. p. 162, 170, 173. Choffat, Especes nouv. ou peu conn., p. 44, 47. 194 University of Texas Bulletin Mammites pseudonodosoides Choffat Pseudaspidoceras cfr. Footeanum Stoliczka Fagesia aff. superstes Kossmat Fagesia aff. tevesthensis Peron Puzosia cfr. Gaudama Forbes Puzosia sp. Pachydiscus peramplus var. beyrense Choffat Pseudotissotia Barjonai Choffat Ammonites cfr. Pachydiscus Rollandi Peron Ammonites sp. ind. From the upper Turonian the author cites: Vascoceras Gamai Choffat Schloenbachia ? Algeria: The Salmurian in northern Africa, especially in Algeria, Tunis and Egypt is very well developed. Still, in the year of 1904, Solger1 could not cite from Algeria more than the following species of cephalopods : According to Peron : Acanthoceras deverioide Grossouvre Sphenodiscus Requiem d'Orbigny (Hoplitoides ingens according to Pervinquiere) Pachydiscus peramplus Mantell and other species of the same genus Neoptychites Telinga Stoliczka (N. cephalotus according to Per- vinquiere) Puzosia Austeni Sharpe According to Coquand: Amm. Fleuriausi d'Orbigny Amm. papalis d'Orbigny Hetet -ammonites ammoniticeras Coquand (Hemitissotia Morreni Coquand according to Pervinquiere) Peron cites further the following species:2 Mammites ? tevesthensis Peron (=Fagesia tevesthensis according to Pervinquiere) Pachydiscus Durandi Thomas et Peron (^Vascoceras Durandi ac- cording to Pervinquiere) Pachydiscus Rollandi Peron (=Thomasites Rollandi according to Pervinquiere) Tunis: In the present time we owe to the painstaking investigations of L. Pervinquiere a much more complete knowledge of the fauna of the iSolger, Mungokreide p. 203. 2Peron, Amm. du Cret. sup. de 1'Algerie. A New Ammonite Fauna of the Lower Turanian of Mexico 195 Salmurian in northern Africa, especially of Tunis. Pervinquiere cites and describes the following cephalopods: Puzosia Austeni ? Sharpe Pachydiscus peramplus Mantell Hoplitoides Munieri Pervinquiere Hoplitoides mirabilis Pervinquiere Prionotropis Neptuni Geinitz Acanthoceras Douvillei Pervinquiere Mammites nodosoides Schlotheim Pseudaspidoceras salmuriense Courtiller Pseudaspidoceras armatum Pervinquiere Fagesia superstes Kossmat Fagesia tevesthensis Peron Fagesia Peroni Pervinquiere Fagesia Fleuryi Pervinquiere Vascoceras Durandi Thomas et Peron Vascoceras cfr. barcoicense Choffat Vascoceras polymorphum Pervinquiere Thomasites Rollandi Peron Thomasites Meslei Pervinquiere Thomasites Jordani Pervinquiere Pseudotissotia segnis Solger Pseudotissotia Pavillieri Pervinquiere Pseudotissotia Luciae Pervinquiere Pseudotissotia Massipiana Pervinquiere Neoptychites cephalotus Courtiller Neoptychites xetriformis Pervinquiere Neoptychites Courguechoni Pervinquiere Egypt: Until a very few years ago our knowledge of Turonian faunas of Egypt was rather fragmentary, but in 1911 Eck published a prelim- inary study1 of the collections made by Schweinfurth which contain faunas of the Cenomanian, Turonian and Senonian. From the lower Turonian Eck cites the following cephalopods : Neolobites Schweinfurthi Eck Fagesia bomba Eck Fagesia cfr. tevesthenensis Peron Vascoceras cfr. amieirense Choffat Vascoceras Kossmati Choffat aEck, Turon in Aegypten. (On account of the war I have not been able to obtain the later work of the author.) 196 University of Texas Bulletin Vascoceras Durandi Thomas et Peron Vascoceras barcoicense Choffat Pseudotissotia segnis Solger Pseudaspidoceras cfr. Footeanum Stoliczka Hoplitoides sp. (?) Hoplitoides cfr. mirabilis Pervinquiere ( ?) Southern Sahara: In Africa there are other localities where fossils indicating- the existence of the Salmurian in a facies similar to that of Portugal, Tunis, Egypt, etc., have been found. Chudeau1 describes some cephalopods from Damergou, a region which lies nearly exactly where Longitude 9°E Greenwich crosses Latitude 15°N. This author cites from that part: Vascoceras Cauvini Chudeau Acanthoceras Gadeni Chudeau According to the author Vascoceras Caudini is similar to V. Durandi Thomas et Peron. Nigeria? Woods2 describes several cephalopods from northern Nigeria which seem to belong to Turonian forms. The species described are the following : Vascoceras Nigeriense Woods (similar to V. Durandi Thomas et Peron) Vascoceras Gongilense Woods (similar to V. subconciliatum Chof- fat) Pseudaspidoceras sp. (similar to Ps. Footeanum Stoliczka) Hoplitoides Nigeriensis Woods (similar to H. Munieri Pervinquiere) Kamerun: One can not doubt that the above cited fauna represents the Turonian and probably the Salmurian; therefore it is rather astonishing that a similar fauna has not been discovered in Kamerun, where only the Neoptychites of the Mungo remind us of Salmurian forms. Solger sup- poses that the Turonian exists in that region, but Guillemain and Harbort3 maintain that the beds in all their extension belong to the Emscherian. From what we have seen in the foregoing description we conceive the idea that in northern and central Africa and in Portugal exists a facies of special features representing the Salmurian. This facies is distin- guished by the frequence of the genera: Vascoceras, Fagesia, Neopty- chites, Pseudaspidoceras, and in second place Pseudotissotia, Thomasites and Hoplitoides. Chudeau, Ammonites du Damergou, p. 66. 2Woods, Cret. dep. northern Nigeria, pp. 281-286. 3Guillemain und Harbort. Profil der Kreidesch. a. Mungo, p. 431. A New Ammonite Fauna of the Lower Turanian of Mexico 197 Syria and Palestine: Of this characteristic fauna nothing seems to be known in other parts of the Mediterranean. In Syria and Palestine, Turonian beds are scarcely known. Notling cites from there a cephalopod similar to Prionotropis Woolgari, and Diener cites a Mammites nodosoides. This does not prove that .the Salmurian in its north African facies does not exist there, because only a few years ago we did not know any more about the Turonian of Egypt, until Eck published his first lists of cephalopods. Southern France: It seems that on the European border of the Med- iterranean the north African facies of the Salmurian with its character- istic fauna of cephalopods is yet unknown. In France the same horizon has quite a different fauna. In Provence there are, according to Gros- souvre,1 beds with: Mammites nodosoides, M. conciliatus and Pseudo- tissotia Douvillei, but at least the first two of these species are nearly universally distributed types. Pervinquiere adds to this list Fagesia Boucheroni Coquand. In Aquitania the following cephalopods have been found : Pseudaspidoceras salmuriense, Fagesia superstes ?, Fagesia Bou- cheroni Coquand, Fagesia tevesthensis, and Neoptychites cephalotus. Thus this fauna contains quite a good number of the Salmurian fauna of the Mediterranean, although in the case of Fagesia and Neoptychites it seems that only very rare specimens have b.een found. Saxony and Bohemia: The fauna of tli- Salmurian in Saxony and Bohemia contains a still smaller number of elements which might belong to the Mediterranean facies. Fritsch- describes from there as Mammites conciliatus Stoliczka a form which certainly belongs to this group, although as Kossmat already has noted, the species is different. The same author cites Acanthoceras Neptuni. Laube and Bruder3 figure Mammites nodo- soides and other species of this genus, as well as Puzosia Austeni. Petra- scheck* cites Mammites Footeanus Stoliczka, Mammites cfr. crassitesta Stoliczka, Barroisiceras ( ?) Fleuriausianum d'Orbigny, Acanthoceras cfr. Choffati Kossmat; all forms of groups which in part occur around the Mediterranean and in part in India. Northern Europe: The faunas of the Salmurian of northern France and nothern Germany show much less similarity with the Mediterranean facies. They contain only ammonites belonging to groups of a universal distribution, like Mammites nodosoides, Barroisiceras (?) Fleuriausianum, Acanthoceras Neptuni, Pachydiscus peramplus, Puzosia Austeni, etc. Of course, we have to take into consideration that neither in northern Ger- 'Grossouvre, Craie Superteure, Stratigr., p. 507. 2Fritsch, Ceph. bohm. Kreideform., p. 35. 3Laube und Bruder, Amm. d. bohm. Kreide, p. 229. «Petrascheck, Amm. d. sachs. Kreideform., p. 155. 198 University of Texas Bulletin many nor in Bohemia is there a modern stratigraphic-paleontological work on the Turonian fauna. Less still do we know about England, from which Solgar could cite only a very few species as probably of Turonian age. From the foregoing we see that the more we advance toward the north, the more the elements belonging to the Mediterranean facies of the Sal- murian diminish. India: Certain faunal relations exist between the Salmurian of India and that of the Mediterranean. In India the group of Mammites nodo- soides is represented by two species, Mammites conciliatus Stoliczka and M. crassitesta Stoliczka; the group Pseudaspidoceras by one, Ps. Footea- num Stoliczka. The genus Fagesia is represented by two species, Fagesia superstes Kossmat, and F. Rudra Stoliczka. In the same manner we find Neoptychites represented by two species: Neuptychites Telinga Stoliczka (=cephalotus Courtiller according to Pervinquiere) and N. xetra Stoliczka. Japan: In Japan there is probably also Turonian with elements of the Mediterranean facies. Yabe cites the occurrence of beds with Mammites. In these he found a Mammites of the group of M. nodosoides Schlotheim.1 The same author describes a Fagesia Kotoi which occurs either in the same beds or in those with Scaphites, which are a little younger. Australia: It seems that in Australia the Turonian has not yet been found; at least the fossils found in the Desert Sandstone, considered by Jack and Etheridge as the representative of the upper Cretaceous,2 do not allow such a conclusion. Brazil: In South America only very few localities have been discov- ered where fossils of the Salmurian have been found. Some species were described from Brazil by White but without any indication of their age. Several authors have already noted that the Salmurian must exist there, but it seems nearly impossible to separate the Salmurian fossils from those of the other Cretaceous horizons. Pervinquiere notes the similarity between Vascoceras Durandi and Ammonites Harttii Hyatt,3 while Choffat who had before that time called attention to the similarity between that species and his Vascoceras harttiforme Kossmat believes that A. Harttii might be a Fagesia, but the suture published by Hyatt4 shows that the species belongs to Vascoceras. Kossmat has also indicated the similarity between Ammonites pedroanus iYabe, Strat. u. Pal. Hokkaido, p. 441. -Jack and Etheridge, Queensland, p. 557 et seq. 3White, Brazil, p. 226, pi. 19, figs. 1, 2; pi. 20, fig. 3 (erroneously called A. Pedroanus in the explanation of the plate and in the text). *Hyatt, Pseudocer., pi. 14, fig. 16. A New Ammonite Fauna of the Lower Turanian of Mexico 199 White1 and Pseudaspidoceras Footeanum Stoliczka. This species is found at the same locality (Bom Jesus, Larangeiras, Provincia de Sergipe) where Vascoceras Harttii occurs. It is therefore probably safe to say that the Salmurian exists in that region in a facies similar to that of northern Africa. Pervinquiere finally has noted that his Vascoceras polymorphism is very similar to Ammonites offarcinatus White,2 a species found at Trapiche das Pedras Velho, Porto dos Barcos and Bom Jardin in the Province of Sergipe. It seems to me probable that this type belongs to the multi- tuberculated Vascoceras. Peru: Species from the Salmurian have also been found in Peru. Lis- son3 described and figured in 1908 two specimens of Vascoceras which he identifies with Vase, amieirense Choffat. There can be no doubt that this form is a real Vascoceras very similar to Vase, amieirense, although the Peruvian form is a little more involute and the cross-section different. Later on Lisson4 cites from Cuesta de Huanambra, in the province of Caja- marca, a Mammites nodosoides var. Afra Pervinquiere, but notes that the fossil seems to occur in the lower Senonian (Emscherian). From the same locality he cites Hoplitoides ingens v. Koenen ; this makes the deter- mination of the first species doubtful or indicates that both the Salmurian and the Emscherian exist in this locality. This latter opinion is con- firmed by a geological cross-section published by Schlagintweit,5 whose locality "Cuesta de Huanyanba," is probably identical with the "Cuesta de Huanambra" of Lisson, as both indicate that the place lies to the west of Celendin. Schlagintweit gives the following cross-section: 6. Senonian beds. 5. Few meters of marly limestones of yellow color with Mammites nodosoides Schlotheim. Turonian. 4. About 15 m. sandy dolomitic limestone. 3. Few meters of yellow marls of the Cenomanian with Exogyra columba Lamarck. 2. 100-150 meters of light-colored limestone. Vraconian. 1. Aptian-Gault with fossils. United States: In the rest of America no fauna similar to the Medit- erranean facies of the Salmurian appears to have been discovered. In the western United States the Turonian is represented by the Eagleford shales, 'White, Brazil, p. 213, pi. 22, figs. 1, 2 (won pi. 20, fig. 3). 'White, Brazil, p. 219, pi. 23, figs. 3, 4. sLisson, Amm. del Peru, p. 9, 9a, 9b. 4Lisson, Terr, recon. en el Peru, II, p. 1. 5Schlagintweit, Vravon u. Cenoman i. Peru, p. 57. 200 University of Texas Bulletin similar to the beds of Mexico, with Inoceramus labiatus ; and in the central United States by the Benton and the Colorado formation. This latter probably contains also the Emscherian. The cephalopods collected in these beds are entirely different from those of the Mediterranean Salmurian and seem to occur in slightly younger beds. Possibly the Salmurian may yet be found in Texas, as there is only a short distance between this state and our locality. From the foregoing we reach the conclusion that our fauna of Cerro del Macho has very near relations with the African and Portuguese facies of the Salmurian and that a similar fauna probably exists in South Amer- ica on the Pacific coast (Peru) as well as on the Atlantic border (Brazil). In South America, especially in Peru, the similarity with the faunas of north Africa appears to begin even in the Cenomanian (Schlagintweit) and to persist still in the Senonian (Lisson), while in Mexico we can not say the same, although in the Cenomanian as well as in the Senonian there exist certain elements which remind us of forms from north Africa. We certainly have to take into consideration that the fauna of the Ceno- manian of Mexico is still very little known, only the faunas of Cerro del Muleros and of the Vraconian of Camacho, Zacatecas, having been studied in detail; and this latter fauna resembles entirely that of Europe. The few fossils contained in the probably Cenomanian beds of Cerro del Macho seem to indicate in a certain degree that the upper Cenomanian of this region has a fauna similar to that of north Africa; but this problem can only be solved in the future when larger collections have been made. The Salmurian faunas of the African-Portuguese region as well as those of Cerro del Macho have some, although not very near, relations with the Salmurian of India and Japan, the connecting elements consisting of a few groups of Mammites, Pseudaspidoceras, Fagesia and Neoptychites; and we might even say that our facies is as much related to that of India and Japan, as it is to that of France and Saxony-Bohemia. I do not pretend that these results are to be considered as definite, because the Salmurian in general is yet very little studied, not only in far away countries like India and Japan but also in a great part of Europe. PALEONTOLOGY— CEPHALOPODA METOECOCERAS Hyatt Hyatt1 proposed the name of Metoecoceras2 for the forms belonging to the group of Ammonites Swallovi Shumard and united in the genus the iHyatt, Pseudocer., p. 116. 2I accept the proposal of Pervinquiere to change the original name Metmcoccras into Metoecoceras. A New Ammonite Fauna of the Lower Turanian of Mexico 201 following species : M. Swallowi Shumard, M . gibbosum Hyatt, M. Whitei Hyatt, M. acceleratum Hyatt, and M. Kanabense Hyatt (figured but not de- scribed). These are forms similar to Acanthoceras in one direction and to Pulchellia in the other ; they are always involute, with relatively flat flanks, a nearly rectangular or lanceolate cross section, much higher than broad. The ornamentation consists of straight or slightly flexous ribs which begin at the umbilical border without forming real nodules in that region, al- though in some cases they show slight thickening in that place. The ribs continue on the flanks, showing near the ventral border a thickening or very little pronounced nodule, and on the ventral shoulder a very sharp nod- ule which is somewhat longitudinally prolonged and very near the above mentioned thickening. Between the main ribs other secondary ribs are intercalated which begin above the umbilical border in different heights ; the main ribs are often bifurcated. Between the two rows of nodules on the ventral shoulders there is a flattened zone, smooth in some cases while in others the very low ribs cross this zone. The nodules of the two ventral shoulders frequently form a kind of undulated or interrupted keels. The suture of small individuals resembles that of Heinzia and Pulchellia, while that of larger specimens is similar to the suture of certain groups of Acanthoceras (Mantelliceras) and Acompsoceras. Characteristic is the ex- ternal saddle divided by a secondary rather deep lobe ; the first lateral lobe is broad and not very deep, the first lateral saddle is narrow but in general higher than the external saddle; the second lateral lobe is narrow and short, showing scarcely half of the depth of the first one. The second lat- eral saddle is similar to the first one but much lower; there are always three or four auxiliary saddles or even more in very large specimens. All the saddles are very little ramified, the auxiliary ones often entirely whole. The first lateral lobe seems to be always bifid. Very characteristic also is the manner of involution in this genus. While the internal whorls are completely involute, the external whorl covering the greater part of the inner one, we see that the larger whorls and the animal chamber show a much wider curve and cover a much larger part of the next smaller whorl. The species belonging to this group are so characteristic that one has to consider them as an independent genus or subgenus. Hyatt considers this group as a special family, giving it a position between the Heinzidae and the Mantelliceratidae. To the species united by Hyatt in the genus Metoecoceras we probably have to add some European forms. One of these is Pulchellia Gesliana Petrascheck1 from the upper Cenomanian of Saxony. Petrascheck con- 1Petrascheck, Amm. d. sachs. Kreideform., p. 140, pi. 7, figs. 3-5. 202 University of Texas Bulletin siders this species as a Pulchellia and it certainly has the greatest sim- ilarity with this genus if we do not take into account Metoecoceras. . Com- paring the figures of Petrascheck with those of the American Metoeco- ceras we note a surprising similarity ; for example, between figure 4 of Pe- trascheck and figure 2 of Stanton,1 and between, figure 3 of Petrascheck and figure 10 of plate 15 of Hyatt.2 The suture of the specimens from Saxony is imperfectly known, but the elements which can be recognized in figure 4 of plate 7 and figure 5 of the text (p. 141) of Petrascheck, coincide very well with those of Metoecoceras. Petrascheck identifies his specimens with Ammonites Geslianus d'Or- bigny,* but Sayn points out that the figure of d'Orbigny differs very much from the figures of Petrascheck. It is possible that Ammonites Geslianus d'Orbigny belongs also to Metoecoceras but this can not be decided as long as the suture is entirely unknown. The specimen figured by Gueranger" under the name of A. Geslianus is so badly preserved that no details can be recognized. What Geinitz5 figures as A. Geslianus d'Orbigny seems to differ considerably from the type and belongs perhaps to Stoliczkaia. Pe- trascheck accepts the determination of Geinitz but does not figure any specimen which shows the transition between the smooth ventral part and the form in which the ribs pass the venter without interruption. Kossmat6 has noted the external similarity between Acanthoceras vici- nale Stoliczka7 and "Buchiceras" Swallovi Shumard, indicating at the same time the difference in the suture which is much more complicated, especially in the auxiliary saddles of the Indian species. Still more similar to M. Swallovi is a cephalopod from Madagascar de- scribed by Boule, Lemoine and Thevenin8 under the name of Acanthoceras (Prionotropis) subvicinale. The suture of these specimens coincides per- fectly with that of Metoecoceras, as has already been observed by the au- thors, but it also has a great similarity with Pulchellia. The specimens are very small and show an ornamentation very similar to that of Metoecoce- ^tanton, Colorado Form., p. 168, pi. 38 (Buchiceras Swallovi White; according to Hyatt, this is a new species, M. Whitei, Hyatt). 2Hyatt, Pseudocer. • 3D'Orbigny, Pal. fran c.,terr. cret., ceph. p. 325, pi. 97, figs. 1-2 (under the name of Am. catillus Sow.; this determination was corrected by d'Orbigny in Prodrfime II, p. 146). 4Gueranger, Album Paleontol., pi. 5, fig. 2. 5Geinitz, Elbthalgebirge I, p. 280, pi. 62, fig. 3. 6Kossmat, Siidind. Kreideform., p. 201 (105). 'Stoliczka, Ceph. Cret. Rocks India, p. 84, pi. 44. Kossmat, Siidind. Kreideform.. p. 200 (104), pi. 25 (11), fig. 2. "Boule, Lemoine et Thevenin, Diego-Suarez, p. 31, pi. 8, fig. 5; fig. 16 of the text. A New Ammonite Fauna of the Lower Turonian of Mexico 203 ras; they differ principally by the presence of a median row of scarcely perceptible, very small tubercles on the ventral part. Unfortunately the specimens are all very small, therefore we can not know if this row of tu- bercles becomes stronger in larger specimens, or if it disappears com- pletely, or if it persists in larger individuals in the same manner as in juvenile specimens. Hyatt does not mention the existence of a median row of tubercles in juvenile specimens of Metoecoceras. Acanthoceras subvicinale occurs in the Cenomanian of Diego-Suarez. Thus we see that in Europe as well as in India and Madagascar there seem to exist forms which resemble the Metoecoceras of America. Prob- ably we have to include in this genus at least Pulchellia Gesliana Petras- check and perhaps also Ammonites Geslianus d'Orbigny. Very similar is also Acanthoceras subvicinale Boule, Lemoine et Thevenin, especially on account of the suture, while Acanthoceras vicinale Stoliczka, although showing a very similar ornamentation, differs by its more complicated suture. But we should note that the suture changes considerably in the different Metoeceras of America, that of M. Whitei being much more com- plicated than that of M. Swallovi (in the limitation of Hyatt). At pres- ent we can not decide how many forms should/ be included in the genus Metoecoceras, but can only indicate that this genus is probably represented in the Cenomanian of Europe and perhaps of Madagascar, and that similar forms but with a much more complicated suture, are found in the Ceno- manian and Turonian of India. METOECOCERAS aff. WHITEI Hyatt » PL 12 figures 4, 7 1876: Buchiceras svallovi White, Inv. foss. Nevada, Utah, etc., p. 202, pi. 20. 1893: Buchiecras svallovi Stanton, Colorado Form., p. 168, pi. 37, fig. 1 (?pl. 38, figs. 1-3). 1903: Meloicoceras Whitei Hyatt, Pseudocer., p. 122, pi. 13, figs. 3-5, pi. 14, figs. 1-10, fig. 15. In the lower bed of Cerro del Macho occur two fragments of cephalopods which greatly resemble the group of Metoecoceras Whitei: they are espec- ially similar to specimens figured by Hyatt. Our individuals show the fol- lowing features : Shell discoidal, very involute, with whorls of nearly rectangular cross section, much higher than broad. The flanks are very little convex, nearly flat, the ventral portion is flattened. The umbilicus is extremely narrow. The ornamentation consists of strong ribs which begin on the umbilical 204 University of Texas Bulletin border; they are slightly thickened near the umbilical border but do not form real nodules. Between these main ribs other secondary ones are in- tercalated ; they begin above the umbilical border and are a little less strong on the flanks than the main ribs. The ribs are slightly bent forward on the flanks but do not considerably increase in strength. Near the ventral shoulder the ribs show a tuberculiform thickening and from this point bend more strongly forwards ; they end on the ventral shoulder in a strong nodule which is longitudinally prolonged. Between the two rows of nod- ules on the ventral shoulders we observe an entirely flat and smooth zone of the venter ; the ribs do not continue over the ventral portion, but every pair of the ventral nodules is connected by a slight thickening, which pro- duces on the ventral zone a slight undulation. The suture is only partly visible. We recognize the external saddle, the first lateral lobe, the first lateral saddle and the second lateral lobe. The suture is not very well preserved because this part of the specimen is some- what corroded, but still we are able to note the general character. The ex- ternal saddle (compare figure) is broad and divided into two parts by a rather deep secondary lobe ; the first lateral lobe is broad and shallow, end- ing in two points, and on the sides are two rather large branches ; the first lateral saddle is higher than the external one, its ramifications are few and simple ; the second lateral lobe is much shallower than the first one, and it is also narrower and trifid. In this specimen the umbilical portion is not preserved but one sees that the second lateral saddle remains rather far from the umbilicus, therefore several auxiliary lobes and saddles must have existed in the intermediate space. Figure 1. Metoecoceras aff. whitei Hyatt, suture The ornamentation of our specimens coincides perfectly with that of Metoecoceras Whitei Hyatt, only on the ventral part we do not observe as A New Ammonite Fauna of the Lower Turanian of Mexico 205 deep furrows as in Hyatt's plate 13, figure 3, but simply an undulation. As far as the suture is visible it corresponds with that of M. Whitei, especially with that of plate 14, figure 8 of Hyatt. I do not identify my specimens with M. Whitei because they are not sufficiently well preserved, but I am sure that they belong to the group of M. Whitei. We know very little about the stratigraphic position of M. Whitei; some of Hyatt's originals have been found in the Kanab Valley, Utah. According to Walcott and Stanton1 the species occurs there up to a height of 335 feet above the base of the Cretaceous. Stanton refers that division to his Colo- rado Formation which probably contains several horizons, perhaps from the upper Cenomanian, or at least from the lower Turonian to the Emsche- rian. For the determination of the age of our beds the species found in the United States do not help us much. On the other hand, we do not know any European form which might be identified with our species, although this has a great similarity with Pulchellia Gesliana Petrascheck from the upper Cenomanian of Saxony, as we have shown in the stratigraphical part. Number of specimens : 2. A//e: Upper Cenomanian (?), lower beds of Cerro del Macho. METOECOCERAS sp. nov. PI. 12, figs. 1-3 The collection of Dr. Haarmann contains a specimen of Metoecoceras which is certainly different from the species described above ; unfortunately we do not know in which horizon this specimen has been found ; according to its petrographical character it belongs to Horizon I, but it might have been found also in Horizon II. Its features are : Shell discoidal, very involute, with whorls of a lanceolate cross section truncated in the ventral part, much higher than broad. The flanks are a little convex, the ventral' portion is flattened. The ornamentation consists of rather strong ribs, which are slightly flexuous and which bend forward. These begin near the umbilical border, where they are slightly thickened, but do not form nodules. Part of these ribs bifurcate below the middle of the height of the flank. Between these main ribs we find other secondary ones intercalated which begin in different heights of the flank, and which at their beginning are less strong than the main ribs. All the ribs show near the ventral shoulder a slight thickening of a kind of very low and rounded nodules ; on the ventral shoulder the ribs end in a nodule which is longi- tudanally elongated. These nodules form together a kind of interrupted 'Stanton, Colorado Form., p. 35. 206 University of Texas Bulletin keel on both sides of the ventral portion. Between the rows of nodules we observe on the ventral portion a rather broad, flat and smooth zone. With respect to the involution we observe that the last whorl seems to show a tendency to form a wider curve than the preceding whorl. No part of our specimen shows a trace of the suture. According to its form and ornamentation our specimen belongs certainly to Metoecoceras, and I unite it provisionally with this genus although the suture is unknown. The species differs from M. Whitei Hyatt typus in its' flexuous ribs, but it resembles the specimens figured by Stanton1 in figures 1-2 of plates 38 and called Buchiceras Swallovi. Hyatt unites it with his Metoecoceras Whitei, notwithstanding that it differs much from the type. It seems that our spec- imen has a smaller number of ribs than that figured by Stanton and that the ribs are more flexuous. Our species resembles much more Pulchellia Gesliniana Petrascheck2 than the above described species. This similarity is really very great but our species is distinguished by a smaller number of ribs which are also less flexuous. I do not doubt that both species belong to the same group. Meto- ecoceras Geslinianum Petrascheck occurs in the upper Cenomanian in Saxony. Number of specimens : 1. Age : Upper Cenomanian ( ?) or lower Turonian. MAMMITES Laube et Bruder, Emend. Petrascheck MAMMITES MOHOVANENSIS sp. nov. PI. 12, figs. 6, 8 In Horizon II of Cerro del Macho there has been found a well preserved specimen of Mammites, and also several fragments belonging to the same species. They show the following features : Shell globose, rather involute, with whorls of a trapezoidal or nearly subquadrangular cross section, much broader than high. The umbilicus is rounded. On the umbilical border we observe six thick nodules, which are rather pointed and a little rounded. In these nodules begin broad, rounded, radial ribs, partly simple, partly in pairs. Between these ribs are interca- lated generally two secondary ribs also low and rounded, which begin above the umbilical border, but without showing nodules at their beginning. On these secondary, as well as on the main, ribs we find two strong and rounded 1Stanton, Colorado Form. 2Petrascheck, Amm. d. sachs. Kreideform., p. 140 (10), pi. 7 (1), figs. 3-5. A New Ammonite Fauna of the Lower Turanian of Mexico 207 nodules near and on the ventral part. These nodules form two rows, each of which is composed of 16 to 17 nodules on the last whorl ; those of the row on the ventral portion are a little elongated longitudinally. Thus we find on each side of the shell three rows of nodules : the umbilical, the interme- diate and the ventral row. It seems that the nodules of the intermediate row increase in thickness in the front part of the whorl, while those of the ventral row decrease a little and extend themselves more longitudinally, but none of the specimens is large enough to show the development of the nodules in an advanced age. Between the two ventral rows we observe a narrow concave zone in the inner whorl and a nearly flat one on the exter- nal whorl. The suture is very much destroyed but its main features can still be recognized. The external lobe is rather deep and narrow, ending in two branches ; the external saddle is broad and high, divided into two branches by an adventive lobe of relatively great depth ; the first lateral lobe is deep and ends in two points ; the first lateral saddle is apparently broad but its exact form can not be recognized because the shell is much destroyed in this part. Dimensions: Diameter 87.0 mm. (1) Height of the last whorl 33.0 mm. 0.38 Width of the last whorl 42.0 mm. 0.48 Diameter of the umbilicus 23.0 mm. 0.26 Height of the last whorl in the same diameter but half a whorl backwards 30.5 mm. 0.35 Width of the last whorl in the same diameter and half a whorl back- wards 39.0 mm. 0.46 Our species certainly belongs to the group of Mammites nodosoides Schlotheim. Its suture coincides in general fairly well with the one figured by Laube and Bruder1, but its form and ornamentation resemble more that of Mammites conciliatus Stoliczka,2 which differs from the type of the group especially by the greater thickness of the whorl and the more numerous nodules on the ventral portion. Our species differs from Mammites conciliates by its more involute form, the external whorl covering nearly two-thirds of the preceding one. barely leaving uncovered the row of umbilical tubercles. We find another difference in the number of intermediate and ventral nodules, which is much less in our specimen than in the species of Stoliczka. In this direc- tion our individuals resemble more the type of Mammites nodosoides, but 'Laube und Bruder. Amm. d. bohm. Kreide, p. 230. 2Stoliczka, Ceph. Cret. Rocks India, p. 99. pi. 50, fig. 4; pi. 51, fig. 1. 208 University of Texas Bulletin they differ from this as well as from M. conciliatus through the small dis- tance between the two ventral rows of nodules. In these comparisons I take as type of the species M. nodosoides, the specimen figured by Laube and Bruder because this comes from the same locality as the originals of Schlotheim, which were never figured. Similar to our specimens is also the small individual figured by Pervin- quiere1 as a typical M. nodosoides. Fritsch2 figures a Mammites under the name of Ammonites conciliate Stoliczka, and Kossmat3 confirms the conclusion that this specimen is very nearly related to the species from southern India; he notes that the main difference consists in the involution. In this direction the Mammites con- ciliatus Fritsch resembles more our species than that of Stoliczka. Though in this latter species the external whorl barely covers the preceding one up to the row of intermediate nodules, we observe that in the specimen fig- ured by Fritsch the external whorl covers the preceding one nearly to the row of umbilical nodules. The group of Mammites nodosoides has a quite universal distribution ; it is represented in the lower Turonian of all Europe, of Africa, Asia, and South America. In North America we probably find it represented by Ammonites Loewianus White,4 an observation previously made by Per- vinquiere. Number of specimens: 3. Age: Lower Turonian (Salmurian), lower horizon. PSEUDASPIDOCERAS Hyatt emend. Pervinquiere PSEUDASPIDOCERAS aff. FOOTEANUM Petrascheck 1902: Mammites Footeanus Stoliczka, Petrascheck, Amm. d. sachs. Kreideform., p. 144, pi. 9, fig. 1. Among the material collected by Dr. Haarmann in the lower horizon of the Turonian of Cerro del Macho is a rather large, not very well preserved but quite characteristic cephalopod, showing the following features : Shell moderately evolute with whorls of a subrectangular-oval cross- section, much higher than broad. The flanks are flattened, the ventral portion rounded. The umbilicus is moderately wide, the umbilical wall is 1Pervinquiere, Paleontologie Tunisienne, pi. 18, fig. 1. 2Fritsch, Ceph. bohm. Kreideform., pi. 7, figs. 1, 2. 'Kossmat, Siidind. Kreideform., p. 22 (129). 4Stanton, Colorado Form., p. 178, pi. 43. figs. 3-4. Some authors write Am laevi- anus but it must be Loewianus because the species was dedicated to Dr. Oscar Loew. A New Ammonite Fauna of the Lower Turanian of Mexico 209 abrupt. The ornamentation consists in widely separated, low, rounded, nearly straight ribs which begin in a nodule at the umbilical border and which end in another very high and pointed nodule at the ventral shoulder. Between the two rows of nodules on the ventral part we observe a broad, slightly convex and smooth zone. In the last half whorl we count five ribs. The suture is not visible. Dimensions: Diameter 280mm. (1) Height of the last whorl 117 mm. 0.42 Width of the last whorl 94 mm. 0.34 Diameter of the umbilicus 104 mm. 0.37 Our specimen certainly belongs to the group of Pseudaspidoceras Foot- eanum Stoliczka,2 but differs from it by its cross-section which is much higher than wide. This is not an absolutely distinctive character because we should take into consideration the large size of our specimen and we do not know the latest development of the species of Stoliczka. Our speci- men resembles Pseudaspidoceras Footeanum Petrascheck more than it does the type. The cross-section of the species of Petrascheck is more similar to ours and also has widely separated ribs. The group of Pseudaspidoceras Footeanum Stoliczka has a very wide distribution; it is represented in all the northern part of Africa (we in- clude in this group Ps. salmuriense) , in Nigeria, in Portugal, in Saxony, and in India. Number of specimens : 1. Age: Lower Turonian (Salmurian), lower horizon. PSEUDASPIDOCERAS aff. PEDROANUM Whit^ PL 13, fig. 1; PL 15, fig. 1 1887: Ammonites Pedroanus White, Brazil, p. 212, pi. 22, figs. 1, 2 (not pi. 20, fig. 3). In the lower horizon of the Turonian of Cerro del Macho we find a large and relatively well preserved specimen which belongs to the group of Pseudaspidoceras Footeanum Stoliczka. Its features are: Shell large with whorls of a subquadranglar cross-section, nearly as high as wide. The flanks are flattened, the ventral portion is nearly flat. The umbilicus is relatively wide and deep, the umbilical wall is vertical but without a sharp umbilical shoulder. The external whorl covers only the ventral portion of the preceding one and leaves the nodules of the ven- tral shoulder free. The ornamentation consists of extremely low and 2Stoliczka, Ceph. Cret. Rocks India, p. 101, pi. 52, figs. 1, 2. 210 University of Texas Bulletin rounded, nearly straight ribs which sometimes are scarcely perceptible; on the last whorl we count thirteen of these ribs. The ribs begin on the umbilical border in a strong and pointed nodule and end with another and still more prominent but somewhat longitudinally elongated nodule on the ventral shoulder. Between the two rows on the ventral shoulders we observe a smooth and very slightly convex zone which does not show any signs of nodules or ribs ; only the two last nodules seem to be connected by a kind of low rounded rib which crosses the smooth zone of the venter. Between the nodules of the rows on the ventral shoulder we find some ribs or nodules intercalated which do not correspond to umbilical nodules. Traces of the suture are visible in different parts but I have not been able to draw a complete line. Dimensions : Diameter: 214 mm. The last part of our specimen bemg somewhat crushed and twisted, we have taken the following dimensions frcm a little smaller diameter : Diameter 164mm. (1) Height of the last whorl 63 mm. 0.38 Width of the last whorl 70 mm. 0.43 Diameter of the umbilicus 59 mm. 0.36 Height of the last whorl on the same diameter but half a whorl back- wards 42 mm. 0.26 Width of the last whorl on the same point 45 mm. 0.27 Our specimen belongs, as we have already mentioned, to the group of Pseudaspidoceras Footeanum Stoliczka1 which it resembles in its involu- tion, the cross-section of the whorls, the two series of prominent nodules, etc. It differs from the type through its weaker ribs, and the entire ab- sence of ribs and nodules on the ventral portion and of a concave zone along the line of symmetry on the ventral portion. Our species shows much nearer relations to Pseudaspidoceras pedroanum White from Brazil than to the type of the group. It has the same kind of involution, a very similar cross-section, a nearly identical ornamentation; it only seems to differ a little with respect to the nodules on the ventral shoulder, which according to the figure of White are connected on the last part of the whorl by a kind of low crest, which is also mentioned in the text. White also says that in very large individuals the nodules on both sides of the venter are connected by a crest which crosses the venter. We have indicated a similar phenomenon in the last two nodules of our specimen. We thus see that our species resembles in a surprising man- ner Ammonites pedroanus Kossmat and others have already recognized A New Ammonite Fauna of the Lower Turanian of Mexico 211 that this species belongs to the group of Pseudaspidoceras Footeanum. White compares his species with Ammonites Leonensis Conrad, which is probably a Schloenbachia, and also with Prionotropis Woolgari. We know nothing about the age of the beds where the type of the species has been found but the similarity with Pseudaspidoceras Footeanum allows us to conclude that they probably belong to the Salmurian. In this idea we are confirmed by the circumstance that in the same locality Vascoceras Harttii Hyatt has been discovered. Number of specimens : 1. Age: Lower Turonian (Salmurian), lower horizon. FACES I A Pervinquie're FACES I A HAARMANNI sp. nov. PL 14, figs. 1, 2; PL 15, fig. 2 In the lower bed of the Salmurian of Cerro del Macho Dr. Haarmann found a not quite complete specimen of so characteristic a Fagesia that I have no hesitation in giving it a new name. Another more complete but somewhat deformed specimen collected by Dr. E. Wittich, was given to me by Mr. Federico Ritter. The features of the larger specimen are : Shell moderately involute with whorls of transversally elliptical cross- section, much broader than high. The umbilicus is rather narrow and deep; the umbilical wall is abrupt, in the internal whorls nearly vertical. The ventral portion is broad and slightly convex, the region of the flanks is very narrow and one might say scarcely developed and in reality only represented by the umbilical nodules ; the ventral part nearly touches the umbilical wall. The ornamentation consists on the umbilical border of some nine very strong, pointed and round nodules. From these nodules start rounded, broad, rather high ribs which cross the ventral portion without interruption in a curve directed toward the front; in general a pair of ribs starts from each nodule and one or two more become inter- calated between every two pairs. This disposition can not be observed with entire certainty because the border of the whorl is a little broken. The suture could not be made visible. Dimensions: Diameter 165 mm. (1) Height of the last whorl 52 mm. 0.32 Width of the last whorl ?74 mm. 0.45 Diameter of the umbilicus 66 mm. 0.40 212 University of Texas Bulletin At the first view1 our species resembles greatly a Stephanoceras, a simi- larity which has been noted also in other species of Fagesia especially Fagesia superstes Kossmat.1 From this species, which represents the type of the genus, our species differs by being much more evolute and by its stronger ribs; the umbilical nodules are less numerous and thicker, the ribs are also less numerous and a little stronger. Our species is certainly the most evolute one of all the Fagesia so far described, but its nearest relative is without doubt Fagesia superstes Kossmat. According to the figure published by Kossmat no nodules can be seen on the internal whorls, while in our species these nodules can be distinguished even on the smallest whorls. The occurrence of this species is of certain stratigraphical importance in so far as it belongs to a very characteristic group which seems at present to be limited to the Turonian. According to Pervinquiere only six species are known and all of these belong to the Turonian. Fagesia superstes, which resembles ours more than any other species, has been found in India (upper Utatur group) and in Tunis (lower Turonian) ; similar forms have been discovered in the Turonian of Portugal and France.2 Number of specimens : 2. Age: Lower Turonian (Salmurian), lower horizon. FAGESIA PERVINQUIERI sp. nov. PI. 14, fig. 3 In the lower horizon of our Salmurian we find a relatively well preserved specimen which belongs to Fagesia but differs essentially from the fore- going species by its entirely different form and the weaker ornamentation. Its general features are: Shell subglobose, very involute, with whorls of transversally semilunar cross-section. The umbilicus is narrow and deep, the umbilical wall is nearly vertical. On the umbilical border of the internal whorls appear not very strong nodules; on the last part of the external whorl the um- bilical border seems to be entirely smooth. On the internal whorl we observe numerous broad and low ribs which are strongest in the central part of the ventral portion, while they seem to flatten out toward the umbilical border. On the ventral portion the ribs curve slightly toward the front. The number of ribs could not be counted because the ventral iRossmat, Siidind. Kreideform., p. 26 (133), pi. 6 (17), fig. 1. 2Pervinquiere, Paleontologie Tunisienne, p. 325, note 5. A New Ammonite Fauna of the Lower Turanian of Mexico portion of the last whorl is a little corroded, but there are certainly more than forty on the last whorl. The suture is not visible. Dimensions: Diameter 94mm. (1) Height of the last whorl 36 mm. 0.40 Width of the last whorl 60 mm. .0.64 Diameter of the umbilicus 31 mm. 0.33 Height of the last whorl on the same diameter but half a whorl backwards 27 mm. 0.29 Width of the last whorl at the same point 55 mm. 0.59 On account of its general form and its ornamentation I place this speci- men in the genus Fagesia although the suture could not be made visible. Our species is quite similar to Fagesia tevesthensis Peron1 especially the large specimen figured by Pervinquiere- (pi. 20, fig. 6). This individual shows on the umbilical border nodules quite similar to those of our speci- men. But the African species has much broader and lower whorls which in part may be explained by its stage of development, because all the species of Fagesia change their cross-section of the whorls with their age and grow more rapidly in width than in height. Another species which resembles ours is Fagesia rudra Stoliczka.3 This species shows very similar ribs and the umbilical border is entirely smooth. Fagesia rudra differs from our species by its much broader and lower whorls. Unfortunately only a single specimen of our species has been found. It was impossible to study the internal whorls in their details and there- fore we can not make more detailed comparisons with other species. Number of specimens: 1. Age: Lower Turonian (Salmurian), lower horizon. VASCOCERAS Choffat When Choffat4 established his new genus Vascoceras he subdivided it into four groups: 1. mono-tuberculated forms with wide umbilicus; 2. subglobose forms with rounded umbilical border ; 3. globose forms with angular or subangular umbilical border; 4. multi-tuberculated forms. These groups could be called: 1. Group of Vascoceras Gamai; 2. Group 'Peron, Amm. du Cret. sup. de PAlgerie, p. 23, pi. 7, figs. 2, 3. 2Pervinquiere, Paleontologie Tunisienne, p. 325, pi. 20, figs. 5, 6. 3Stoliczka, Ceph. Cret. Rocks India, p. 122, pi. 60, fig. 1. «Choffat, Especes nouv. ou peu conn., p. 51. 21-1 University of Texas Bulletin of Vascoceras Douvillei; 3. Group of Vascoceras harttiiforme; 4. Group of Vascoceras subconciliatum. Pervinquiere1 unites the first two groups in one and distinguishes only three subdivisions. This seems to me to be the best solution, as the divi- sion of the first two groups appears to be rather artificial. Among the material of Cerro del Macho we find forms representing the three groups. To the first one (in the sense of Pervinquiere) belongs our Vascoceras aff. Gamai Choffat and Vascoceras aff. adonense; to the second one Vascoceras Angermanni sp. nov., and perhaps Vascoceras aff. arnesense Choffat; to the third one Vascoceras mohovanense n. sp. The genus Vascoceras so far has been found in Portugal, Spain, Algeria, Tunis, Egypt, the Sahara, Nigeria, Brazil, Peru, and Mexico. VASCOCERAS sp. nov. ex aff. V. ADONENSE Choffat PL 14, fig. 4; PL 17, fig. 2 1886: Vascoceras adonense Choffat, Especes nouv. ou peu conn., p. 59, pi. 9, fig. 3; pi. 21, fig. 12. Our specimen shows the following features: Internal mold rather large, a little oblique on account of deformation, quite evolute, with whorls of a transversally semi-lunar cross-section, much broader than high. The umbilicus is wide, the umbilical wall is quite abrupt, the umbilical border is rounded and scarcely subangular. In the external whorl no nodules exist on the umbilical border; the internal whorls are not visible. The surface of the species is smooth, no orna- mentation can be distinguished. The suture is very simple ; it is not very well preserved but the general features can be well distinguished. The external lobe is quite wide and not very deep and ends in two branches; the external saddle is wide at the base, becoming narrower upward, and is very little ramified; the first lateral lobe is funnel shaped, very wide at the mouth ; the first lateral saddle is similar to the external one but smaller and inclined toward the umbilicus while the external one rather bends over toward the venter; the second lateral lobe is funnel shaped, very wide at the mouth and much shallower than the first one; the second lateral saddle (on the umbilical border) is similar to the first one but smaller. The dimensions could not be measured exactly on account of the de- formation of the specimen. Pervinquiere, Paleontologie Tunisienne, p. 331. A New Ammonite Fauna, of the Lower Turanian of Mexico 215 With respect to its external form our species resembles Vascoceras adonense Choffat, but this latter species shows nodules on its umbilical border, while these are entirely missing in our specimen. This might be explained by the stage of development, our individual being much larger than that of Choffat, but our species is certainly much more evolute. A Figure 2. Suture, Vascoceras angermanni n. sp. (above) and Vascoceras aff. adonense Choffat (below). fundamental difference can be found in the suture. In the type species we find on the umbilical border the first lateral saddle, but we see that in our specimen the second lateral saddle is in this place. In its general character our suture is much more similar to that of Vascoceras Gamai. Our species therefore has to be considered as a new form which in its external figure resembles Vascoceras adonense while the suture places it in the vicinity of Vascoceras Gamai. We can not give it a new name because the specimen is too badly preserved. Number of specimens: 1. Age: Lower Turonian (Salmurian), lower horizon. 2T6 University of Texas Bulletin VASCOCERAS aff. GAMAI Choffat PI. 15, figs. 3-5 1886: Vascoceras Gamai Choffat, Especes nouv. ou peu conn., p. 54, pi. 7, figs. 1-4; pi. 8, fig. 1; pi. 10, fig. 2; pi. 21, figs. 1-5. In the collection made by Dr. Angermann I found a cepholopod which probably represents a juvenile stage of some species belonging to the group of Vascoceras Gamai. Judging from the petrographical aspect of the specimen I suppose that it was found in the upper horizon of the Salmurian of Cerro del Macho. Its features are : Shell relatively small, quite involute with whorls of a subquadrangular rounded cross-section, broader than high. The umbilicus is narrow and probably deep, the umbilical wall is abrupt. The flanks are flattened, the ventral part rounded. On the umbilical border we count seven thick, round, and pointed nodules. From each of these starts either a pair of ribs or a simple rib, which curves slightly forward and crosses without interruption the ventral portion. Between these main ribs one or two secondary ones are intercalated. These begin above the umbilical border, but on the venter are as strong as the main ones. The ribs are thick, broad, rounded, wider than the interstices by which they are separated. On the ventral shoulders the ribs seem to have u tendency toward a slight thickening but real nodules do not form there. On the anterior part of the last whorl, and especially on the ventral region, the ribs seem to dis- appear. This region is partially corroded but in a place which is well preserved one notes clearly that the ribs are very low and scarcely per- ceptible on the line of symmetry. Figure 3. Suture, Vascoceras aff. gamai Choffat The suture is very little ramified. The external lobe has two branches and is quite deep and narrow; the external saddle is little ramified, broad and rounded ; the first lateral lobe is less deep than the external one and rather narrow. The first lateral saddle is little ramified and resembles in its form the external one, but is narrower. Our specimen resembles the juvenile form figured by Choffat in figure 4 A New Ammonite Fauna of the Lower Turonian of Mexico 217 of plate 7 ; unfortunately no figure of the form viewed from the side has been published. The juvenile specimen of figure 3 of plate 7, the lateral view of which is given in figure 2 of plate 10 of Choffat is also similar. The main difference exists probably in the smaller number of umbilical nodules in our specimen and in the narrower cross-section, although this latter feature changes with the age. In the juvenile specimens of Vascoceras Mundae the ribs are less numer- ous and thicker. Vascoceras Gamai Choffat occurs in Portugal mainly in the lower and middle Turonian of Choffat, both of which according to my opinion belong to the Salmurian. Number of specimens: 1. Age: Lower Turonian (Salmurian), probably from the upper horizon. VASCOCERAS ANGERMANNI sp. nov. PI. 16, figs. 1-4; PI. 17, fig. 1 In the collection of Dr. Angermann as well as in that of Dr. Haarmann we find a globose cephalopod which at the first view resembles completely a Nautilus. In the collection of Angermann there is a small, quite well preserved specimen, and in Mr. Haarmann's collection a much larger one, but the features of both are the same. There are also a number of frag- ments which probably should be united with this singular species. Its features are : Shell large, globose, extremely involute, with whorls of semi-lunar cross- section, much broader than high. The whorls cover the preceding ones nearly entirely. The umbilicus is narrow and deep, the umbilical wall abrupt, the umbilical border smooth and angular. The surface of the shell is entirely smooth without any nodules or ribs. The suture is not very well preserved but its general features can be well recognized. The external lobe is quite deep and moderately wide, ending in two branches. The external saddle is moderately broad, quite high, very little ramified ; the first lateral lobe is little ramified, broad, ends in two points and is deeper than the external one ; the first lateral saddle is broad and rounded, less high than the external saddle. The second lat- eral lobe is probably similar to the first but less deep ; it is not entirely pre- served. Dimensions of the smaller specimen : 218 University of Texas Bulletin Dimensions: Diameter 75 mm. (1) Height of the last whorl 32 mm. 0.45 Width of the last whorl 69 mm. 0.92 Diameter of the umbilicus 14 mm. 0.19 Height of the last whorl on the same diameter but half a whorl back- wards 27 ^..-n. 0.36 Width of the last whorl at the same point 62 mm. 0.83 Diameter of the largest specimen : 124 mm. Our species resembles greatly Vascoceras Kossmati Choffat1; it is of course evident that all the species belonging to this group must be very similar, as none of them shows any ornamentation. The main difference between our species and Vascoceras Kossmati consists in the different curve of the cross section of the internal whorls, which is always of greater radius. The suture is also different, the saddles of our species be- ing relatively higher and the lobes deeper. One might add that our species grows to a larger size than the Portuguese species. Vascoceras Kossmati Choffat has been found in Choffat's middle Turon- ian of Portugal, which, according to my opinion, belongs to the Salmurian. In Egypt it occurs in the lower Turonian.2 Our larger specimens have been found in the upper bed of the Salmurian of Cerro del Macho and the specimen collected by Angermann belongs to the same horizon, judging from its petrographical character. Number of specimens : 3 and several fragments. Age: Lower Turonian (Salmurian), upper horizon. VASCOCERAS sp. PI. 18, fig. 12 Dr. Haarmann found in the upper horizon of Cerro del Macho a cepha- lopod, the generic determination of which remains somewhat in doubt be- cause its suture can not be made visible. Mr. Frederico Ritter gave me another and a little better preserved specimen which shows traces of the suture. Their features are : Shell subglobose of moderate size, very involute with whorls of semi- lunar cross section, broader than high. Flanks and ventral portion round- ed. The umbilicus is small and deep, the* umbilical wall is vertical and even a little overhanging; the umbilical border is angular. The shell 1Choffat, Especes nouv. ou peu conn., p. 63, pi. 13, figs. 8, 9; pi. 14, figs. 1, 2; pi. 21, figs. 26, 27. 2Eck, Turon in Aegypten, p. 384. A New Ammonite Fauna of the Lower Turanian of Mexico 219 seems to be entirely smooth, no nodules can be observed on the umbilical border. The suture is similar to that of the group of Vascoceras Kossmati but it is not complete enough for a drawing. Dimensions : Diameter 106 mm. (1) Height of the last whorl 43 mm. 0.41 Width of the last whorl 72 mm. 0.68 Diameter of the umbilicus 22 mm. 0.21 One of the specimens is a little obliquely deformed which makes the de- termination still more difficult. The species resembles externally much Ammonites arnesensis Choffat1, the generic position of which is equally doubtful; it seems to me to belong to Vascoceras or to a new subgenous, the suture being quite different from that of the type of the genus. In one of our specimens the suture is not visible ; in the other one we see parts of it which are similar to the elements of the suture of Vascoceras Angermanni. Therefore I place our species provisionally in the genus Vascoceras. Externally this species resembles somewhat Vascoceras Ar- germanm but the umbilicus is wider, the general form less globose, and the whorls are less broad in relation to their height. Number of specimens: 2. Age: Lower Turonian (Salmurian), upper horizon. VASCOCERAS MOHOVANENSE sp. nov. PI. 18, figs. 1-2 Dr. Haarmann collected in the upper bed of our Salmurian a juvenile individual of a cephalopod which certainly represents a new species. Its features are : Shell small, subglobose, quite involute with whorls of trapezoidal cross section, much broader than high. The flanks are somewhat flattened, as is also the ventral part. This gives the cross-section its angular form. The umbilicus is narrow and deep, the umbilical wall is abrupt, the um- bilical border is angular. The ornamentation consists in the last whorl of about eleven high and pointed nodules (nearly all broken in the present specimen) on the umbilical border; from each of these generally starts a pair of ribs. Between this pair of ribs now and then secondary ribs are intercalated which begin above the umbilical border. The ribs are thick 'Choffat, Especes nouv. ou peu conn., p. 68, pi. 13, fig. 10 ; pi. 14, fig. 3, pi. 22, fig. 39. 220 University of Texas Bulletin and high. They become a little lower on the venter but cross it without interruption; no longitudnal furrow exists on the venter. On the ventral shoulders the ribs thicken a little, forming on each shoulder a row of ra- dially elongated nodules ; these are not very strong and rather low. These nodules make the ventral shoulders appear angular and the ventral zone more flattened than concave. Figure 4. Sutures, Vascoceras mohovanense n. sp (above) and Mammites mohovan- ensis n. sp. (below). The suture is very simple. The external lobe is quite wide and deep, and bifid ; the external saddle is broad, low, or a rounded form and a little ramified ; the first lateral lobe is wide, approximately as deep as the exter- nal lobe but much wider, and it ends in two points ; the first lateral saddle is very low, rounded and broad and lies in the umbilical nodule; the form of the second lateral lobe, which lies mostly on the umbilical wall, can not be well distinguished. Dimensions : Diameter 56 mm. (1) Height of the last whorl 21 mm. 0.38 Width of the last whorl 45 mm. 0.80 (with the nodule) Diameter of the umbilicus 19 mm. 0.34 Height of the last whorl on the same diameter but half a whorl backwards 16 mm. 0.29 Width of the last whorl at the same point 34 mm. 0.61 This very characteristic species certainly belongs to the group of Vasco- ceras sub conciliation Choffat1, but it resembles Vascoceras polymorphum 1Choffat, Espfcces nouv. ou peu conn., p. 64, pi. 15, figs. 1-3; pi. 16, fig. 4; pi. 22, figs. 28-31. A New Ammonite Fauna of the Lower Turanian of Mexico 221 Pervinquiere1 more than it does the type. From both species it differs through the absence of an intermediate row of nodules and consequently through the different cross section of tne whorl. From Vascoceras subcon- ciliatum our species is also distinguished by its very reduced and simple suture. In this case it resembles much more Vascoceras polymorphum Pervinquiere, which shows a very similar suture. Pervinquiere has extensively discussed the relations of Vascoceras poty- morphum with the other Vascoceras, as well as with Mammites and Acon- thoceras, indicating the similarity of certain groups of Aconthoceras and Mammites, and emphasizing the singular nature of the suture, which is similar to that of other Vascoceras. I believe that Pervinquiere's reasons are well founded and that the present group should be placed in the genus Vascoceras, especially as this genus is nearly related to Acanthoceras and Mammites; therefore the similarity between certain groups of the three genera is not very surprising. Vascoceras polymorphum Pervinquiere occurs in the lower Turonian of Tunis; Vascoceras subconciliatum Choffat is found in beds of a similar age in Portugal. Pervinquiere also emphasizes the similarity between this group and a cephalopod from Brazil, Ammonites offaccinatus White,2 but this latter species is too little known to allow a detailed comparison. The suture is not figured but according to White it is rather complicated. It is therefore possible that it belongs to a different group, or even to a dif- ferent genus. Number of specimens : 1. Age: Lower Turonian (Salmurian), lower horizon. NEOPTYCHITES Kossmat NEOPTYCHITES aff. CEPHALOTUS Courtiller PI. 18, figs. 3, 10, 13 1907: Neoptychites cephalotus Courtiller Pervinqutere, Paleontologie Tunisienne, p. 393, pi. 27, figs. 1-3. Cum syn. • Among our material exists a cephalopod of small size which in its ex- ternal form and its suture resembles the juvenile specimens of Neoptychi- tes. Its features are : Shell subglobose, very involute, last whorl broader than high with nearly Pervinquiere, Paleontologie Tunisienne, p. 336, pi. 21, figs. 2-5. 'White, Brazil, p. 219, pi. 23, figs. 3, 4. 222 University of Texas Bulletin semilunar cross-section. The umbilicus is very narrow; the wall can not be seen. The flanks are slightly convex, the venter is rounded. The orna- mentation consists of low, rounded, broad, numerous ribs (about 32 to the whorl) which apparently do not reach down to the umbilical region and which are strongest on the ventral portion. On the internal whorl we note a well defined and rather broad constriction which toward the front is limited by a slight thickening ; the constriction is especially evident on the venter. The ribs are curved forwards, as is the case with the constriction, although in less degree. Figure 5. Suture, Neoptychites aff. cephalotus Courtiller The suture is very similar to that of Neoptychites and corresponds in general to that of Neopychites cephalotus, although the figure published by Pervinquiere is taken from a much larger specimen ; a little more similar still is the suture of the small specimen of N. xetriformis, in the above cited work of Pervinquiere (p. 398, fig. 153) , although there the external saddle is more slender than in our specimen. The suture of our individual is not complete and in some places can not be very well followed, but in general narrow, ending in two branches; the external saddle is quite broad and one recognizes the main features. The external lobe is deep and relatively high and little ramified ; the first lateral lobe is a little shallower than the external one, ends in two points and shows also a branch directed obliquely toward the ventral region ; the first lateral saddle is similar to the external one but is lower and narrower. Figure 6. Suture, Neoptychites aff. cephalotus Courtiller Dimensions : Diameter ............................................. ...... 50mm. (1) Height of the last whorl ............................ ^ ........ 2<5 mm. 0.52 Width of the last whorl ...... .......................... " . . ...... 33 mm. 0.66 Our specimen represents the juvenile stage of a Neoptychites similar to the one figured by Pervinquiere in pi. 27 fig. 2, which it resembles much in its external features ; it differs mainly in its great width. But according to Pervinquiere the dimensions change much in the genus, and we should not give too much importance to this feature. A specific determination of our A New Ammonite Fauna of the Lower Turanian of Mexico 223 specimen is not possible on account of its small size ; we can only say that it is a Neoptychites similar to Neoptychites cephalotits but probably a dif- ferent species. Neoptychites cephalotus occurs in the lower Turonian of Tunis, Altrerla and France. Grossouvre proposes to unite it with Neoptychites Telinga. Stoliczka and Pervinquiere accepts this opinion. There is no doubt that the adult individuals of the two species resemble each other very much, although the suture seems to be somewhat different and a little more rami- fied in N. cephalotus; but this last character is not decisive as long as we know only the suture of a very large specimen of N. Telinga.. A definite result can only be reached through the study of the development of N. Te- linga or at least of that of small specimens. Number of specimens : 1. Age: Lower Turonian (Salmurian), upper horizon. NEOPTYCHITES aflf. XETRIFORMIS Pervinquiere PL 18, figs. 9, 11 1907: Neoptychite xetriformis Pervinquiere, Paleontologie Tunisienne, p. 398, pi. 27, figs. 5-7. Among the material collected by Dr. Angermann is a very typical Neop- tychites. The specimen is sufficiently well preserved for a generic deter- mination. Its features are : Shell discoidal, very involute, with whorls of nearly sagittiform cross section, much higher than broad. The greatest width is near the umbilical border. The flanks are quite flattened and very little convex, and the ven- ter is rounded. The umbilicus is extremely narrow and deep ; the umbil- ical wall is vertical ; apparently a slight thickening exists on the umbilical border, at least in the last part of the external whorl. On the flanks we observe radial, broad, low, and rounded ribs which are strongest in the region near the venter and which decrease in strength toward the umbilical as well as toward the ventral region ; they disappear near the umbilicus. On the venter the ribs are very low and scarcely discernible ; near the ven- tral portion, they bend forward. The number of ribs could not be counted because part of the surface is corroded. The suture is not very well preserved but the main features can be rec- ognized. The external lobe is relatively wide and shallow, ending in two short branches; the external saddle is not very high nor very broad but little ramified. The first lateral lobe is wide and ends in two points ; it also has a branch on each side, and is deeper than the external lobe. The first 224 University of Texas Bulletin lateral saddle is narrow, a little lower than the external saddle, and little ramified ; second lateral lobe is similar to the first in its form but smaller and much shallower ; the second lateral saddle is very low and very broad and of oblique form. Dimensions : Diameter 73 mm. (1) Height of the last whorl 40 mm. 0.55 Width of the last whorl 33 mm. 0.45 Diameter of the umbilicus 6.5 mm. 0.09 With respect to its external form our specimen is very similar to Neop- tychites xetriformis; even the dimensions coincide sufficiently, if we take into consideration the variability of Neoptychites. The main difference consists in the ornamentation; the ribs are much more numerous in our species (probably 25 to 30 on the last whorl) and they do not disappear completely on the venter. The specimen thus occupies an intermediate position between N. cephalotus and N. xetriformis, or between this and 2V. xetra, if the small individual figured by Stoliczka1 really belongs to N. Xetra. The suture of our specimen resembles that of N. Xetra still more than that of N. xetriformis. N. xetriformis occurs in the lower Turonian of Tunis. N. Xetra Stoliczka belongs to the lower and middle Utatur group according to Koss- mat, but we should not forget that the determination of the horizons of the Utatur group is in general based on the petrographical character of the fossils and on the locality. The determination of the age is therefore not always certain for each species. How doubtful it sometimes is we can see in our own case. On page 168 (72) Kossmat cites N. Xetra from the lower and middle Utatur group; on page 196 (131) he cites it from the lower and upper Utatur group. This doubt with respect to the age of the different species can not surprise us. because Kossmat could not base his determinations on well divided and stratigraphically well studied cross sections, but rather on general observations and subdivisions based more on the petrographical character of the rocks than on the faunas. Kossmat himself (loc. cit. p. 132 (197)) is convinced that a paleontological and stratijrraphical subdivision of the Utatur group is possible, but until this has been executed in a modern manner, we should not crive too much im- portance to the age which has been assigned to a certain species from In- dia. We should always take into account that in such old collections labels 'Stoliczka, Ceph. Cret. Rocks India, pi. 61, fig. 2. A New Ammonite Fauna of the Lower Turanian of Mexico 225 may have been changed and that the fossils frequently have not been col- lected with the necessary exactness. Number of specimens : 1. Age: Lower Turonian (Salmurian), lower horizon. HOPLITOIDES V. Koenen Emend. Solger et Pervinquiere The genus Hoplitoides has been established by von Koenen1 for certain ammonites from the limestones of the Mungo in Kamerun; later Solger2 studied the same fauna and made the definition of the genus more precise. Then Pervinquiere1 amplified this definition still more and distinguished two groups within the genus Hoplitoides: the bicarinate and the monocar- inate forms. The first group seems to be limited to the Turonian, the sec- ond one to the Emscherian. Among our material we find a few ammonites which very probably be- long to the first group, the bicarinate Hoplitoides. The specimens are not very well preserved and the generic determination is not entirely certain. The external form corresponds completely with that of the Hoplitoides, but the suture is much destroyed and scarcely permits recognition of the general character of the line; this, however, coincides entirely with the suture of the bicarinate Hoplitoides. The character of the suture on the other hand shows that the specimens do not belong to Placenticeras, a genus which externally is quite similar to Hoplitoides. HOPLITOIDES aff. MIRABILIS Pervinquiere PI. 19, figs. 1-3 1907 : Hoplitoides mirabilis Pervinquiere, Paleontologie Tunisienne, p. 218, pi. 10, fig. 3 Among the material placed at my disposition I found two relatively complete specimens and four fragments which, according to their suture and external form, belong to the so-called Pseudoceratites of the Creta- ceous. The best preserved specimen shows the following features : Shell discoidal, entirely evolute, with whorls of lanceolate cross section truncated at the point, much higher than broad. The umbilicus is very narrow, the umbilical wall is vertical and the umbilical border rounded. The flanks are smooth, very little convex, nearly flat. The venter is flat with a sharp shoulder on each side; on the internal whorl we observe on both shoulders of the venter a sharp keel and the zone there is concave. Jv. Koenen, Nachtr. Foss. Mungo i. Kamerun, p. 53. 2Solger, Mungokreide, p. 127. 226 University of Texas Bulletin The suture is badly preserved, because all the specimens are corroded on the surface, and rio suture could be made visible on the internal whorls. We note a little ramified external saddle, which is rather broad and low; the first lateral lobe is broad, shallow and ends in three points, those on the umbilical side being longer than the one on the ventral side. Some smaller ramifications exist on the sides of this lobe. The first lateral i/^ VJ Figure 7. Sutures, Neoptychites aff. xetriformis Pervinquiere (lower left hand corner) and Hoplitoides sp. (other three). saddle is broad and relatively high, and a secondary lobe divides it in two parts. The following saddles are much destroyed and no longer show their ramifications. The lobes are much shallower than the first lateral lobe. Dimensions : Diameter 149 mm. (1) 119 mm. (1) Height of the last whorl 76mm. 0.51 58mm. 0.49 Width of the last whorl 45mm. 0.30 34mm. 0.29 Diameter of the umbilicus 19 mm. 0.13 18 mm.? 0.15 Our specimens belong very probably to the genus Hoplitoides and to the bicarinate group of it. Externally they resemble this group in an extra- ordinary manner and especially Hoplitoides mirabilis Pervinquiere. Per- vinquiere has united these forms, which distinguish themselves by a flat venter even in a very advanced stage, with the Hoplitoides of the Emsche- rian, which show a flat venter only in their youth, the venter in the adult age becoming sharp or a little rounded. Only the study of a large and > A New Ammonite Fauna of the Lower Turanian of Mexico 227 rich material could decide if it would not be better to separate these two groups at least subgenerically. It was probably the want of sufficient ma- terial which decided Pervinquiere not to separate the two Turonian species from the rest of the genus. If such study should prove that all the species from the Turonian belong to .the bicarinate group, it would be better to unite them in a different species. The main difference between our species and H. mirabUis consists prob- ably in the larger diameter of the umbilicus, but our material is not suffi- ciently well preserved to allow a more detailed comparison. The two species of bicarinate Hoplitoides described by Pervinquiere oc- cur in the lower Turonian ; one of them has also been found in the upper Turonian (H. Munieri). Eck1 cites with some doubt Hoplitoides mirabilis, or a similar form, from the Turonian of Egypt. Woods2 describes a Hoplites Nigeriensis from Ni- geria which he takes to belong to the bicarinate Hoplitoides. These spec- imens occur in probably Turonian beds. In the same locality have been found Vascoceras Gongilense Woods and Pseudaspidoceras sp. Woods mentions that Hoplitoides has also been found in another locality of Ni- geria. Number of specimens : 2, and 4 fragments. Age: Lower Turonian (Salmurian), upper horizon. LAMELLIBRANCHIATA AVICULA Bruguiere AVICULA AGUILERAE sp. nov. PI. 20, figs. 1-2, 11-12 The material from the upper horizon of the Salmurian of Cerro del Macho contains a number of specimens of a large and well characterized Avicula. Its features are : Shell thin, of subquadrate form, nearly as high as broad, not very con- vex ; the right valve is a little more convex than the left one. On the an- terior side is a prolongation in form of an auricula which is not quite com- pletely preserved but which certainly was not very long ; on the posterior side we note a prolongation in form of a wing, with a precise limit be- tween this wing and the rest of the shell. The auricula as well as the wing !Eck, Turon in Aegypten, p. 382 and 386. 2Woods, Cret. dep. Northern Nigeria, p. 284, pi. 23, fig. 3; pi. 24, figs. 1-5; fig. 1 of the text. 228 University of Texas Bulletin form with their superior border approximately the prolongation of the cardinal border and do not elevate themselves above the beaks. The beaks are small and pointed. The cardinal border is straight, long, and vertical in relation to the longitudinal axis of the shell. The surface of the shell is entirely smooth and shows only fine concentric striae of growth. All our specimens are internal molds but some have preserved remains of the shell. Our very characteristic species resembles Av icula gravida Coquand.1 The main difference seems to consist in the greater convexity of the valves in this latter species, also in the different position of the beaks in relation to the upper border of the auricula and the cardinal border ; but it is possible that this last difference may be explained as an error of the draftsman, because Coquand mentions expressly that neither the auricula nor the pos- terior wing elevate themselves above the beaks. In every case our species is nearly related to the African one. Coquand mentions that his species occurs in the Turonian (Mornasian)1 ; later on Peron2 corrected this determination of the horizon. He says that he has always found this species in the Santonian, at the ^ase of the Se- nonian, in the beds with Buchiceras and Hemiaster Fourneli. But not- withstanding this correction it is possible that Coquand was right in his determination of the horizon, because Pervinquiere3 also mentions that he has found Avicula gravida in the lower Turonian. The species seems to occur also in the Emscherian, from which horizon it is cited by Pervin- quiere4 who has also found it at the base of the Senonian immediately above the Turonian. The species thus probably lived from the Salmurian to the Senonian; it is of course possible that the specimens found in the different horizons really were different species, although these certainly belong to the same group. At first view, one might believe that our species are identical with Avi- cula pedernalis Roemer1 but Avicula Aguilera does not have the singular scars of that species, which remind us of those of Meleagrina. Roemer has figured them and I have observed them also on a specimen from the Vraconian of Arivechi, Sonora. The general form of Roemer's species is also a little different from ours. Number of specimens : 6. Age: Lower Turonian (Salmurian), upper horizon. Coquand, Geol. et Pal. de Constantine, p. 216, pi. 13, figs. 17, 18. 2Thomas et Peron, Hauts-Plateaux de la Tunisie, p. 241. 3Pervinquiere, Et. geol. Tunisie, pp. 101, 108. 4Pervinquiere, Et. geol. Tunisie, p. 115, 117, 151. A New Ammonite Fauna of the Lower Turanian of Mexico 229 INOCERAMUS Sowerby INOCERAMUS LABIATUS Schloth-aim PI. 20, fig. 5 1813: Oxtracites labiatus Schlotheim in Leonhard's min. Taschenb. VII p. 93, fide Geinitz. 1875: Inoceramus labiatus Geinitz, Elbthalgebirge II, p. 46, pi. 12 cum syn. 1893: Inoceramus labiatus Stanton, Colorado Form., p. 77, pi. 10, fig. 4; pi. 14, fig. 2 cum syn. 1903: Inoceramus labiatus Petrascheck, Inoc. a. Kr. Bohmens, p. 156. In the upper horizon of the Salmurian of Cerro del Macho, Dr. Haar- mann found four Inoceramus of which at least three are typical Inoceramus labiatus Schlotheim. They are relatively small individuals but are en- tirely identical with those from Parras, Mexico, and different European localities. I have discussed this species extensively in Boletin 30 of the Institute Geologico de Mexico; a detailed description of the specimens found on Cerro del Macho does not seem to be necessary. The occurrence of this species at our locality is of some importance because the determination of the age of the Mexican Turonian beds up to the present is entirely founded on bivalves, especially Inoceramus, and this class of fossils is always stratigraphically of less value than the cephalopods. My former determinations are now confirmed by the. oc- currence of Inoceramus labiatus together with typical ammonites of the lower Turonian. Up to the present, Inoceramus labiatus has not yet been found in the lower beds of our Salmurian ; it only occurs in the upper one, and even there it is not very frequent. Of course we can not yet draw any con- clusions from this distribution. The stratigraphical conditions of the region of Mohovano should first be studied with care, larger collections from the lower horizons should be made, so as to show if Inoceramus labiatus really does not appear in those beds ; and finally the relation be- tween the cephalopod beds and the shales with Inoceramus of other re- gions of northern Mexico should be ascertained. Number of specimens: 3 (4?). Age: Lower Turonian (Salmurian), upper horizon. 230 University of Texas Bulletin EXOGYRA Say EXOGYRA HAARMANNI sp. nov. PL 18, figs. 4-8 In the lowest beds of Cerro del Macho numerous specimens of an en- tirely smooth Exogyra have been found. This species resembles to a certain degree Ex. columba Lamarck but is not completely identical with it._ Its character is : Larger valve thin, very convex, especially in the central portion, thus forming a kind of rounded crest which goes from the beak to the lower margin. This crest gives the shell an asymmetric aspect because it is not entirely in the center, but a little nearer the anterior margin ; this asym- metry is particularly noted in large specimens and much less in juvenile individuals. The beak is quite slender, spirally coiled at its point. The valve is broad, without forming wings and without a furrow in any of the sides. From the above mentioned crest the shell slopes rapidly toward the anterior margin and slowly toward the posterior margin. The sur- face is entirely smooth, showing only fine striae of growth and in a large specimen there is an indication of two slight concentric ridges, certainly produced by the manner of growth. The smaller valve is nearly flat. In none of the specimens is the surface entirely preserved and a detailed description of this valve can not be made. Oar species resembles Ex. columba Lamarck but is much smaller and never shows a radial ornamentation, and the rounded crest is nearer to the anterior margin while in the European species it is nearer the posterior one. In its shape our species resembles still more Ex. columbella Meek,1 especially on account of the position of its crest, but the radial ornamenta- tion of that species is entirely missing in ours. Number of specimens : 12 and numerous fragments. Age: Upper Cenomanian?, lower beds of Cerro del Macho. EXOGYRA cfr. OLISIPONENSIS Sharpe 1850: Exogyra olisiponensis Sharpe, Secondary Distr. of Portugal, p. 185, pi. 19, figs. 1, 2. 1911 : Exogyra olisiponensis Woods, Cret dep. Northern Nigeria, p. 278, pi. 20, figs.1-3. cum syn. In the upper part of the marls which we believe belong to the Ceno- manian, Dr. Haarmann found a fragment of a large Exogyra. This 'Stanton, Colorado Form., p. 63, pi. 8, figs. 2-4. A New Ammonite Fauna of the Lower Turanian of Mexico 231 species is distinguished by a moderately broad and coiled beak which slopes quickly toward the anterior margin; this steep slope continues on the valve itself, while toward the posterior margin the valve slopes in a very regular curve. The ornamentation consists of radial, thick, and not very numerous ribs. Where these are crossed by specially strong concentric lamellae of growth, a kind of prolongations is formed which nearly re- semble spines. The shell itself is very thick. The specimen does not seem to be very nearly related to the Exogyra with radial ribs, of the Mexican middle and upper Cretaceous (Ex. Whit- neyi, Ex. costata, etc.) but much more to the varieties with few ribs be- longing to the group of Ex. Olisiponensis from the border of the Med- iterranean. Our fragment is especially similar to an individual from the Cenoma- nian of Wadi Am Rimpf figured by Fourtau1 ; this specimen shows a very similar ornamentation. Very similar also are some specimens from Deba Habe in Nigeria figured by Woods ; these show particularly the strongly sloping region of the shell toward the anterior margin. Exogyra olisiponensis occurs in the Cenomanian as well as in the Turo- nian. Many authors certainly take the species in a very wide sense and we do not yet know if it is possible to separate specifically the form of the Cenomanian from that of the Turonian. In general it seems to me that our specimen resembles more the varieties figured from the Cenomanian (compare among others Lartet, Geol. de la Palestine, pi. 11, fig. 1) than those from the Turonian. With this view the layer in which our specimen has been found coincides well; it occurs in the upper part of the marly limestones directly below the Salmurian of Cerro del Macho. We have considered these marls with some doubt as upper Cenomanian. Unfortu- nately we do not know the exact stratigraphic position of the individuals from Nigeria. Woods presumes that they come from the Turonian, be- cause in Gongila, in Nigeria, not only typical cephalopods of the Turonian (Vascoceras, Pseudaspidoceras, bi-carinated Hoplitoides) have been found, but also specimens of Exogyra olisiponensis, while in Deba Habe only Ex. olisiponensis has been collected. A solution of this problem is im- possible for the moment, but there is the possibility that at Deba Habe the Cenomanian might be represented by beds with Ex. olisiponensis. Number of specimens: 1. Age: Upper Cenomanian (?), upper part of the lowest horizon 6f Cerro del Macho. 'Fourtau. Faune cret. d'fegypte, p. 287, fig. 5. 232 University of Texas Bulletin GASTROPODA TYLOSTOMA Sharpe TYLOSTOMA aff. OVATUM Sharpe PL 20, fig. 3 1849: Tylostoma ovat-um, Sharpe, On Tylostoma, p. 379, pi. 9, figs. 7, 8. In the upper horizon of our Salmurian numerous specimens of gastro- pods have been collected; among these Tylostoma or similar genera seem to predominate. The greater part consists of internal molds which are badly preserved. In some specimens we note that the labrum is thick- ened on the inner side, thus these individuals very probably belong to Tylostoma. It is very possible that there are different species in the col- lection but in consideration of the bad state of preservation of the ma- terial it is impossible, to distinguish them with certainty. The best speci- men, as well as some less well preserved, has much similarity with T. ova- turn Sharpe. Its features are: Shell subglobose, of broad oval form, with a low spire of approximately six coils, mouth suboval and relatively narrow, labrum having an inner thickening. The surface is entirely smooth. According to Choffat1 T. ovatum occurs in all the beds from the Bella- sian to the upper Turonian ; it is thus not very surprising that a similar form is found in our beds. Number of specimens : 5 and probably numerous fragments. Age: Lower Turonian (Salmurian), upper horizon. ECHINODERMATA HEMIASTER Desor HEMIASTER sp. PI. 20, figs. 6-10 In the lower marls of Cerro del Macho, Dr. Haarmann found a Hemiaster which probably represents a new species. He found another specimen loose below the hill which seems to belong to the same species, but it is too badly preserved for determination. The features of the better pre- served specimen are : 'Choffat, Syst. cret. Portugal II, p. 190. A New Ammonite Fauna of the Lower Turanian of Mexico 233 Shell of small size, little convex, slightly polygonal in the ambitus, thin- ning toward the back and toward the front, the greatest width lying far in front of the center of the shell ; slightly notched in front and truncated behind. The upper face is convex, the ambitus rounded, the lower face is nearly flat, a little thickened on the plastron and slightly depressed in the region of the peristome. The impair ambulacrum lies in a relatively broad and moderately deep furrow which begins in the apex and from these regularly widens toward the ambitus, narrowing from there to the peristome; the furrow notches the contour considerably. The zones of pores are composed of pairs of small, nearly circular pores; the pores of each pair seem to be separated by a slight thickening. The zone is wide and nearly smooth ; large tuber- cles are missing there and only the fine granulation can be observed. The zones of pores occupy less than half the furrow between the apex and the ambitus. Farther on follow pores separated by larger intervals and of an oblique position, arranged in such a manner that the pairs of the two zones alternate. The exact number of these pairs could not be counted. The anterior paired ambulacra are moderately large and of lanceolate form ; they lie in relatively deep furrows. The poriferous zones are broad and consist of pairs of elongated, nearly equal pores ; the pores of each pair are connected by a very distinct furrow. The interporiferous zone is rela- tively narrow and has not quite the width of one of the poriferous zones. The posterior paired ambulacra are a little shorter than the anterior ones. The poriferous zones consist of pairs of elongated nearly equal pores; the pores of each pair are connected by a slight furrow. The in- terporiferous zone is rather narrow and less wide than each of the porif- erous zones. Outside of the petals the pores are smaller and the pairs are separated by large intervals. On the whole surface of the interambulacra we observe apparently cren- ulated and perforated tubercles, enclosed by narrow areas and very near together; they are stronger on the anterior portion than on the posterior one. In the interporiferous zones of the ambulacra of the upper face, tubercles do not seem to exist. In the ambulacra of the lower face tuber- cles are infrequent, while the interambulacra of the same face are densely covered by tubercles, especially the plastron; they decrease in size from the center toward the outside. The whole surface of the shell is covered by a fine granulation. The impair posterior inter-ambulacrum of the upper face has a sharp crest which is higher than the apicial apparatus. The anterior interam- bulacra of the same face show much less pronounced crests; the lateral interambulacra are flattened on the center, the flattened zone being lim- 234 University of Texas Bulletin ited by well marked borders. These margins and the crests of the other interambulacra give the polygonal contour to the figure of the shell. The peristome is small and of subpentagonal form. Its position is ex- centric toward the front; the lip is rather prominent. The periproct is not well preserved, but is of oval form and lies in the upper part of the posterior face. The apicial apparatus is relatively large, the two posterior pairs are widely separated from the anterior ones ; the details can not be clearly recognized. Dimensions: Antero-posterior diameter 27.8 mm. Transversal diameter 27.3 mm. Height 19.0 mm. Distance between the apex and the posterior margin 16.2 mm. Our species is not very characteristic but I have not found one with which it might be identified entirely. It resembles to a certain degree Hemiaster Meslei Peron et Gauthier,1 but in this species the posterior am- bulacra diverge much more than in ours, the contour is more notched in front, the furrow of the impair ambulacra is much narrower and deeper. As we have not more than one well preserved individual I only describe and figure it without giving a new name to this species, or identifying it with a known one. Number of specimens: 2. Age : Upper Cenomanian ( ?) , lower horizon of Cerro del Macho. lCotteau, Peron et Gautheir, Ech, foss. de 1'Algerie IV, p. 102, pi. 2, Igs. 5-8. PLATE 12 Metoecoceras, Fagesia, Mammites 236 University of Texas Bulletin Metoecoceras, Fagesia, Mammites. Plate 12 Figures 1, 2, 3. Metoecoceras sp. nov page 205 Upper Cenomanian (?) or lower Turonian. Cerro del Macho, Hacienda de Moho- vano, Coahuila. Fig. 1. View from the opposite side from Figure 3. Fig. 2. Venter of the same specimen. Fig. 3. Side view. Figures 4, 7. Metoecoceras aff. Whitei Hyatt page 203 Upper Cenomanian (?), lower horizon of Cerro del Macho, Hacienda de Moho- vano, Coahuila. Fig. 4. Venter. Fig. 7. Side view. Figure 5. Fagesia Pervinquieri sp. nov page 212 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Venter and cross-section. V Figures 6, 8. Mammites mohovanensis sp. nov page 206 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Fig. 6. Cross-section and venter. Fig. 8. Side view. University of Texas Bulletin No. 1856 ,'. 'Flate 12 PLATE 13 Pseudaspidoceras 238 University of Texas Bulletin PLATE 13 Pseudaspidoceras Plate 13 Figure 1. Pseudaspidoceras aff. Pedroanum White sp page 209 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view. University of Texas Bulletin No. 1856 Plate 13 1 PLATE 14 Fagesia, Vascoceras 240 University of Texas Bulletin PLATE 14 Fagesia, Vascoceras Plate 14 Figure 1. Fagesia Haarmanni sp. nov page 211 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. View of the other side of the specimen figured as Fig. 2, PI. 15. Figure 2. Fagesia Haarmanni sp. nov page 211 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Cross-section and venter of specimen figured as Pis. 15 and 14. Figure 3. Fagesia Pervinquiri sp. nov page 212 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view of specimen figured on PI. 12, fig. 5. Figure 4. Vascoceras n. sp. ex. aff. V. adonense Choffat page 214 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Cross-section and venter. University of Texas Bulletin No. 1856 I M.,..- 14 PLATE 15 Pseudaspidoceras, Fagesia, Vascoceras 242 University of Texas Bulletin PLATE 15 Pseudaspidoceras, Fagesia, Vascoceras Plate 15 Figure 1. Pseudaspidoceras aff. Pedroanum White sp page 209 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Cross-section and venter. Figure 2. Fagesia Haarmanni sp. nov page 211 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view. Figures 3, 4, 5. Vascoceras aff. Gamai Choffat page 216 Lower Turonian, probably from upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Figs. 3 and 5, view of both sides. Fig. 4. Cross-section and venter of the same specimen. University of Texas Bulletin No. 1856 Plate IS PLATE 16 Vascoceras 244 University of Texas Bulletin PLATE 16 Vascocera* Plate 16 Figures 1, 2, 3, 4. Vascoceras Angermanni sp. nov page 217 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Fig. 1. -Side view. Fig. 2. Cross-section and venter of specimen figured on Fig. 4. Fig. 3. Cross-section and venter. Fig. 4. Side view of a larger specimen. University of Texas Bulletin No. 1856 Plate 16 • PLATE 17 Vascoceras 246 University of Texas Bulletin PLATE 17 Vi.coceras Plate 17 Figure 1. Vascoceras Angermanni sp. nov , page 217 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view of a large specimen. Figure 2. Vascoceras n. sp. ex. aff. V. adonense Choffat. page 214 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view of the specimen figured on PL 14, fig. 4. University of Texas Bulletin No. 1856 Plate 17 1 f w PLATE 18 Vascoceras, Neoptychites, Exogyra 248 University of Texas Bulletin PLATE 18 Vascoceras, Neoptychites, Exogyra Plate 18 Figures 1, 2. Vascoceras Mohovanense sp. nov page 219 Lower Turonian, lower horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Fig. 1. Side view. Fig. 2. Cross-section and venter. Figures 3, 13, 10. Neoptychites aff. Cephalotus Courtiller. pags 221 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Fig. 3. Side view. Fig. 13. Cross-section and ventef of the external whorl of the same specimen. Fig. 10. Cross-section and venter of the inner whorl. Fiures 4, 5, 6, 7, 8. Exoyna Haarmanni sp. nov page 230 Upper Cenomanian (?). Lowest horizon of Cerro del Macho, Hacienda de Moho- vano, Coahuila. Fig. 4. Side view. Fig. 5. Side view. Fig. 6. Small valve. Fig. 7. Large valve. Fig. 8. Large valve. Figures 9, 11. Neoptychites aff. Xetriformis Pervinquiere page 223 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Fig. 9. Cross-section and venter. Fig. 11. Side view. Figure 12. Vascoceras sp PaSe 218 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view. University of Texas Bulletin No. 1856 P'«te 18 12 PLATE 19 Hoplitoides 250 University of Texas Bulletin PLATE 19 Hoplitoides Plate 19 Figures 1, 3. Hoplitoides aff. mirabilis Pervinquiere page 225 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Side view of two specimens. Piure 2. Hoplitoides aff. mirabilis Pervinquiere page 225 Lower Turonian, upper horizon. Cerro del Macho, Hacienda de Mohovano, Coahuila. Cross-section and venter of specimen figured on Fig. 3. University of Texas Bulletin No. 1856 f PLATE 20 Avicula, Tylostoma, Exogyra, Inoceramus, Hemiaster 252 University of Texas Bulletin PLATE 20 Avicula, Tylostoma, Exogyra, Inoceramus, Hemiaster. Plate 20 Fiures 1, 2, 11, 12. Avicula Aguilerae sp. nov page 227 Lower Turonian, upper horizon. Cerro del Macho, Hacienda del Mohovano, Coahuila. Fig. 1. Left valve of specimen. Fig. 2. Left valve. Fig. 11. Cardinal margin of same specimen. Fig. 12. Anterior side. Figure 3. Tylostoma aff. ovatum Sharpe page 232 Lower Turonian, upper horizon. Cerro del Macho, Hacienda del Mohovano, Coahuila. Figure 4. Exogyra cfr. olisiponensis Sharpe page 230 Upper Cenomanian (?) Lowest horizon of Cerro del Macho, Hacienda del Moho- vano, Coahuila. Figure 5. Inoceramus labiatus Schlotheim page 229 Lower Turonian, upper horizon. Cerro del Macho, Hacienda del Mohovano, Coahuila. Figures 6, 7, 8, 9, 10. Hemiaster sp. . . . page 232 Upper Cenomanian (?). Lowest horizon of Cerro del Macho, Hacienda del Moho- vano, Coahuila. Fig. 6. Front. Fig. 7. Posterior side. Fig. 8. Left side. Fig. 9. Lower face. Fig. 10. Upper face. University of Texas Bulletin No. 1856 Plate 20 12 INDEX italics d«poie description of species. Abbreviations, tables of fossils 46, 61, 55, 67 Acanthoffra.1 201, 221 cfr. Choffati KOKSIUM 197 neptvni ... 197 prmodosoidet u. L. & f. .. 67 «J>. 44 *i 20' 2L 24. 32- «• 51 limonite and pyrite fauna of 43, 61, 62, 63 Fort "orth formation ..21, 2: marl 41, 46, 53, 64, 62 facies of Descriptions of species __68, et. seq geosynchne Desert sandstone _ 198 limestone 22, 62 Desmoceras brazoense 23 Fossil-bearing beds of Cerro del Macho 183 Diego-Suarez . ..203 Fossils, pyrite 9, 83, 42, 44. 53. 60 Diener, C. _ 197 Fourteau, R. 231 Dieulefit France _ __ 65 France, Salmurian fauna of... DouviUeiceras mammilar'e '.'. "_ 43 Turanian of 212. 223 Duck Creek marl... ...42, 53, 54, 62 Fredericksburg division . fauna of 54, 60 ^f1?8 — limonite and pyrite fauna of 43, 61, 62, 63 _ thickness of upper and lower facies 22 F«tsch, A. ..196, 197, 208 Dumble. E. T. 146 and Cummins, W. F. 18 Gabb, W. F. 25 Durant, Oklahoma 17, 28, 29 Gainesville, Texas, 12, 17, 19, 20, 25, 31. 32. 47, 51, 54 Gainesville Brick Company 31. 36. 47, 51 Eagleford shales 1 43, 199 Gastropoda 137, 191, 232 Echinodermata 232 Gastropods, tabulation of pyritic or limonitic.. 63 tabulation of limonite 61 Gatesville. Texas 14 Echinoidea 101 Geinitz. H. Br. 202 Echinoid fauna of Washita formation 52 Georgetown, Texas 12, 14 of Weno formation 44, 52 limestone 19, 20, 21, 41, 59 Eck, O. 180, 195, 197, 227 Geosyncline, Fort Worth formation 13 Edwards formation _- 24 GerviUiopsis invaginata 34 facies 24. (White) Ill Egypt 214, 218. 227 Ginger shale 36 ammonites from 180 Glenrose formation 14, 43 fauna of 196 Globiconcha sp 140, 168 Salmurian of 193, 196 Gongila, Nigeria .-231 Turonian of 188, 190 Goniopygus sp. 102 Ellenburger limestone 13, 14, 16 Goodland. top of El Paso, Texas 21, 24 fauna of 62 Emscherian, the 190, 196. 200, 205, 225, 226, 228 A New Ammonite Fauna of the Lower Turanian of Mexico 255 Grayson County, Texas 9, 27 thickness of formation in 15 Grayson formation 17, 19, 29, 41, 58 facies of 17 fauna of 48, 66. 60, 63 limonite and pyrite faunae of 61, 62, 63 Graywacke 14 Gryphea 29, 86 mucronata 18, 19 dilatata 20 washitaentit . 21, 28, 29, 41 Grossouvre, A. 146, 223 Guillemain, C. 196 Haarmann. E. ...180. 188, 184. 190. 191, 192. 206. 208. 211, 217. 218, 229. 230 Hacienda del Mohovano 179, 188 Hamites 28. 26. 28 quadrinodofuf Jimbo 71 simplex 42, 69 »P 54 sp. aff. armatvs Sowerby 69 tinaira Adkins and Winton gg llamulina worthengis n. sp. 71, 162 Harbort, E. 196 Haslet. Texas 21, S3, 51, 65 Haug, E. 64, 146 Heinzia 201 Helicocryptus mexicanvs 41 Boese 189 Hemiaster 180, 232 Coirini Clark 17, 42, 114, 168, 191 Fmirneli 228 Meslei Peron et Gauthier 234 sp. tSt, 252 riovistae n. sp. Its, 160 Hill County, Texas 20, 85 thickness of formation 16 Hill. R. T. 16, 46. 146 Hillsboro. Texas 13 Holanter sp. aff. simplex Shumard 104 tvbglobomw 48 Holectypus limitis 88, 108 Homarua 62 Hood County, Texas 17 Hoplitoides 189. 196. 225. 231 aff. mirabilis Pervinquiere tts, 250 ingens v. Koenen 199 mirabili* Pervinquiere 190, 226 Munieri 190, 227 niaerientw 227 sp. 226 Hoploparia 62 Horizons, fossil 12 Hugo, Oklahoma 19, 24, 29 Huronian slates 14 Hyatt, A. __ 201, 202 India, fauna of _- 198, 200, 209, 212 Inoceramus Sowerby 229 hercynicus Petrascheck 179, 191 Inl'itituH Schlotheim 179. 186. 190, 192. 200. tS9, 252 cycloide* 191 Institute Geologico de Mexico 229 Jack R. L. 198 Japan. Turonian fauna of 198 Johnson County. Texas 9, 20, 85, 61, 54 thickness of formations in 15 Johnston, A. W. . ._ 14 Juarez, Mexico 191, 192 Kamerun, Africa 189, 225 fauna of 196 Kanab Valley, Utah 206 Kent, Texas 16, 18, 25, 35 Kiamitia formation 23, 40, 68, 54 conglomerate clay, fauna of .. M facies ""•*' 91 Kidney shale ""."." Kingena ~™S~f ~ 38 Koenen. A. von ~~~. ' 225 Kossmat, A. igg, 198~"2(>2~"2087"224 -191 Lamellibranchia _______ Lamellibranchiata ____ """227 Lamna _________ Lartet, L. ........... ~" •"£ Laube. G. C. . — ...... _•___. ""197" 207 Lemoine, P. . ""«V ion o Leander. Texas .:~~~"~:. T..' 18°' 2Jf Lensing, in Comanchean formations"" Leiocidaris . _____________ 2!)"~ini Leon Springs. Texas .. Liddle, R. A. ____________ ~ Limonite and pyrite fauna of Africa""" of Europe ____________________ of Madagascar . of Texas ........... ----- summary of ... Lisson, C. I ....... . a Lithological changes .. ' ,« Loew. Oscar _________ """208 Love County, Oklahoma Lunatia sp. ---------- '"il'Ttn" tfta McLennan County, T«as "-Tr:.".".".'.".'!! 86, 64 66 Madagascar ---------- 209 9nv . pyritic fossils of 209 2°2' Mainstreet limestone .. ~rrr~™""48,"V7","BV 59 facies ~_ f£- }jj fauna of sandstone in Mammites ~" " 2o6""221 cfr. cranaitetta Stoliczka "197" iqs conciliates ""107 } Fntech i"."~~ lm Steliczka _ ~"fBR~~9n7~~on< -186. tot, 236 Laube et Bruder. emend. Petrascheck""" "_tna Mohovanenng n. sp. 186. toe. 220, 286 nodosotden Schlotheim. .186, 197, 198, 199 207 208 var. Afra Pervinqniere ' 199 Mantelliccras 201 Mariscal Mountains, Texas fg~ 41 Marshall County, Oklahoma ___IH" thickness of formations Medina County. Texas " 68~ 69 Meleagrina ' ...is Metoecoceras .. 19l" Mn""9ni""->n9 aff. Whitei Hyatt Geslianum Petrascheck sp. nov. . igs> 192, t'os, 2S5 ^VIMei* 2°2'' 20S Metopaster 'hortensae Adkins" "•nd'wfnton "" 97 162 Mexico _ a-,* and West Texas — IIIIII_II"i; 41 Mornasian 228 Mortoniceras n- »P- 1™"™-~ ;il»ir"l60 worthense 43 Mungo region, of Africa "_19e""226 Myra, Texas _!.!____ 13 Nacreous fossils, Weno 26, 44. 64 - NautHiu sp. gg texanua fc .r, ., j Neoptychites -"-"-V."."."_".V."."l967200,' 221 aff. cephalotus Courtiller 189, ttl. 248 aff. xetriformix Pervinquiere 179, US, 226 248 erataus Solger igg telingaeformis Solger " 139 256 University of Texas Bulletin Telinaa Stoliczka 189, 198, 223 xetra 224 xetriformis 189, 222, 224 Nerinea sp. Nerita sp. ***• 168 Neritina sp. «». 168 Nigeria, fauna of 196, 209. 214, 227, 231 Nodosaria texana 18, 19, 28, 32, 34, 41, 146, 170 Noetling, F. 146, 197 Noland's River North Central Texas North Denison sands _.: Northern Europe, fauna of - France, fauna of Germany, fauna of Tunis, pyritic fauna of 66 Nucula —29. 31, 3: nokonis n. sp. — 118, II wenoensis n. sp. -. . — 1*0, 168 Oklahoma 40 Opal, Zacatecas .—60, 191 Ostrea(Alectryonia}quadrir>licata Shumard _ carinata carinata ? Lamarck . columba major — • 193, 194 foisseyi Lemoine _. 6| marcoui quadriplicata 20, 28, 29, 31, 32, 36, 41 sp. aff. diluviana Linnaeus -- subovata Ostreidae Oxyrhina Pachydiscus peramplus _ Pachymya Paleontology Palestine, fauna of _ Paluxy sand Parker County, Texas, thickness of formation-- 16 Parras, Mexico 229 Pawpaw formation 9, 41, 42, 43, 51. 53, 60, 62 clay facies of 32 correlation of 1°, 40 facies of 11. 20, 26. 27 fauna of 44, 45, 60-63 fossils 9, 10 ironstone of limonitic and pyritic fauna of 61-63 lithology 26, 27 location of outcrop --9, II marl facies S< thickness 26, 26, 33 changes in 10, 12 sandstone facies shales 45 stratigraphy Pecos, Texas 1? Pecten - 29, 33 georgetownensix (Kniker) _ inconspicuus Cragin 123, 170 mbalpinus 17, 29, 31 Pedinopsis symmetrica (Cragin) . Pelecypoda Pelecypods, pyritic or limonitic, tabulation of — 63 Peltastes sp. ._.102 Pennsylvanian strata .--18, 14, 1 Pentaceras ainericanus n. sp. 3.9, 162 Pentagonaster teitnsis Adkins and Winton— S5, 162 Peron, A. «6, 194 Peru, Salmurian fauna of _. . — 199, 200, 214 Pervinquiere, L. 42, 45, 64, 66, 146, 189, 194, 196, 208, 212, 221, 222 Petrascheck, W 186, 186, 197, 201, 202 Petrographical horizons 183 Phyllocr.raa forbexiatium d'Orbigny : 67 diegoi Boule, Lemoine and Thevenin 67 Pinna 33 yuadalupe Boese 41 Placenticeras 226 Placonmilia 63 bravoensis 41 mexicana 41 gp. 41 Plicatula sp. 29 Polytechnic well. Fort Worth 13 Porto dos Barcos 199 Portugal, fauna of 196, 209, 214, 217 Turonian fauna of, 186, 187, 188, 193, 212, 218, 221 Pre-Cambrian strata --. 18. 14, 16 Primrose, Tarrant County 54 Prionotropis 202 Woolgari 197, 211 Protocardia 34 multistriata 20 «p. aff. mltistriatum (Shumard) 1X6, 168 sp. aff. texana 20 texana 17 Protozoa 145 Province of Sergipe, Brazil 199 Pseudaspidoceras 196, 198, 200, 231 aff. Footeanum Petrascheck 186, tOS aff. pedroanum White 187, 209, 238 Footeanum Stoliczka 186, 198, 199, 209, 210 pedroanum White 210 aalmuriense 197, 209 sp. 227 PfteudotisBotia Douvillei 197 Ptychoceras 69 Ptychodun ' 63 Puzosia Austeni 197 Pyrite ammonites 42, 55, 66, 58, 69, 60-61, 64-67 fauna, comparison of 53 of North Texas Comanchean 53-67 of Pawpaw formation 44.47-53 summary of 60-67 Pyritic starfishes 54 Quarry limestone 29, 31, 32, 35, 36, 37 Quihi, Texas 68, 59 Red River J 64, 55 Red River valley 19. 20, 21, 27, 36 Reed Plateau, Texas 59 Regularia 62 Remondia 32 Remondia? acuminata (Cragin) 1S6, 160 Rhone basin 65 Richardson, G. B. 147 Riovista, Texas 12, 20, 25, 51 Ritter, Frederico 183, 211. 218 Roanoke, Texas 17, 18 Roberts, Jno. R. 41 Roemer, F. 228 Round Rock, Texas 19 Rudistid facies 17, 24 Runnels County, Texas 25 Sahara desert, the 214 Salenia sp. Salenidae 62 Salmurian, faunas of, 186, 199, 194, 195, 196, 208. 211, 212, 213, 215, 217, 218, 219, 227, 228, 231 Santonian 228 Saumur, France 189 Saxony, Cenomanian of — 186, 209 fauna of 197 Saxony-Bohemia, Sa'murian of 200 Sayn. G. 64, 147, 202 Scapkites .-26. 2: aefjualia 42, 67 Hilli Adkins and Winton '9, 162 sp. —54, 69 sp. aequalia 43 wortkenftis 16 Sch'agintweit, O. 199, 200 Schlvcnbachia 211 A New Ammonite Fauna of the Lower Turanian of Mexico 257 ftobieiuu _.> 48 in/lata - 42 manteUi 48 sp ._ 17. 23 trinodosa 23 rarian* 43 wenoennif n. %v. 89, 160 wint&ni n. sp. 90, 164 Schweinfurth. collections of ...195 Sellards. E. H. 14. 147 Senonian ...179, 190, 1»9, 200. 228 Shafter, Texas 16. 18 Sharks, remains of 68 Sheffield. Texas 16, 24 Shuler. E. W. 62 Sierra Blanca. Texas 16, 26 Sierra Mojada. Mexico _ 183 Sladen. P. 147 Slate, Pre-Cambrian _ 14 Solirer. Fr. 194. 196. 198, 226 Solitario. the _ 68. 60 Sonora. Mexico 18 South America, Salmurian fauna of 198. 208 South Bosque. Texas _ 19, 68 South Bosque River 5V South Central Texas 40 Southern France, fauna of 197 Sahara, fauna of 196 Spain __^ 214 Spencer, W. K. 147 Stanton 201, 205. 206 Starfishes, pyritic 54 Ste-nonia sujifrnut iCnmini 62 Stephanocera* 212 Stephenson, L. W. 20. 36. 40. 46 Stoliczkaia 202 Stoliczka. F _. 207. 223. 224 Stratitrraphy 13. 183 Sugar Loaf Mountain. Bryan County. Okla- homa „ 28, 29 Sulphur Creek _. 29 Sycamore Creek _-_33. 38. 39, 47. 51 Syria, fauna of 197 Szjanocha. L. 43, 147 Tah'e of fossils: of Del Rio clay 58-69 of Denton clay _.i. 66 of Duck Creek formation ._ 55 of Grayson marl 67-68 of Pawpaw formation 51-52 of Weno formation 48-50 pyritic and limonitic _61-66 Taff. J. A. 29. 30 Tarrant County, Texas _ _ 9, 12. 20. 23. 33. tt. Yl.'l't. 55 thickness, of formation ._ 15 Terliniroa. Texas ._ 16, 58, 59 Creek _ 60 Thevenin, A. 67, 202 Thicknesses, of Comanchean ~~. .. 15 ThomajtitfK " 196 Tishominfro, Okla Tifiaotia spp. 44 Trapichc das Pedras Velho, Braiil... !IIl99 Trigonia 29, 32. 179 Trinidad mine ' go Trinity division, thickness of ] '~_ 15 TrofhoKmilitt gjj Trochus laticonicu* n. sp. ~~lYs~~168 Tucumcarii. N. M. __18 '0 Tunis 46, 66. 187. 190. 196, 212. 214. 221. 223 ' 2~> I fauna of 194 Turonian .-205. 2«fi 208 209. 212. 213. 215. 217, 219. 221. 223. 226' 228 correlation of 10 of Mexico V 179 <"«> Turonian. Lower, Ammonite fauna of-.. '_ 179 TurninK point of outcrop Id northern, at Orlena, Cooke County 27 ' southern, Bexar County 19, 21, 24 Turrilites 26, 28 bo8iiuvnnix n. sp. 76. 164 brtuotnn* 19, 31, 38, 41 sp. 33. 64. 69. 7S, 154 worthenttig Adkins and Winton 78, 154 Turritflla 28. 29 t/rayttonennia n. sp. ~14<), 168 •p. 54 U'orthcnnin n. sp. 141, 168 TyloKtoma ovatuin 232 Type collection 68 Udden. J. A. .. 14 Union Station, Denison " 47 United States, Salmurian lacking in 199 Turonian fauna of 199 Utatur trroup, of India 187, 212, 224 Valangian 61 Voscocxro* 196. 213, 221, 231 adonenne 186, 187 aff. adonense 214, 216 aff. arnesenae Choffat 214 aff. Gamut Choffat 214, 216. 242 amieirense Choffat 199 Angermanni 219 sp. nov. 214, 216, Sir, 244 Caudini 196 Douvillei 214 Durandi 193 ex. aff. Gamai Choffat IIIIIlSS Gamai 213. 216 Gongilentte Woods 227 Harttii Hyatt ". illzil harttiiforme 214 KoKsmati 179 mohovanenae n. sp. 189, 214, SIS, 248 Mundae 216 n. sp. ex. aff. V. adanense Choffat 114, 240 liolynioriikum Pervinquiere 189. 199, 220. 221 sp 189. tlS, 248 Hubcanciliatum 214, 220, 221 Venericardia wenoennis n. sp. 125, 160 Von Koenen, A. 225 Vraconian. correlation of 10 faunae __ 23, 42"".~66,~~66~, 67 of Arivechi, Sonora 228 Waco __67, 58 Wadi Am Rimpf ...231 Walcott. C. G. __205 Washita division 42, 46 fauna of 43. 44, 52, 64. 60-62 thickness of 15 Weno formation 9, 20, 33. 43, 46, 61, 62 correlation of 10 4(1 facies n, 20, 26, 27 fauna 45.50 fossils 12 ranjre of 46 table of 48-60 litholoiry 26. 27 location of outcrop 9, 10 sandstone in , .' 20 stratigraphy of ~ 13 thickness of 26. 26 changes in 10, 12 West Texas 41 and Mexico ._ 41 Whitney. F. L. 102 147 Winton. W. M. 9, 28, 32. 33. 146. 147 and Adkins .. i r, Wittich, E. . IIIIIIIIIIIIIzil Woodbine? flora 44 Woods, H. 1M, 227, 231 Yabe. H. igg Zacatecas. Mexico go \ 14 DAY USE RETURN TO DESK FROM WHICH BORROWED EARTH SCIENCES LIBRARY This book is due on the last date stamped below, or on the date to which renewed. Renewed books are subject to immediate recall. LD 21-50m-4,'63 (D6471810)476 General Library University of California Berkeley 11 / Illl lUI I