DEPARTMENT OF THE INTERIOR

BULLETIN

OP THE

UNITED STATES

GEOLOGICAL SURVEY

No. 97

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1893

UNITED STATES GEOLOGICAL SURVEY

J. \f. POWELL, DIRECTOR

THE

MESOZOIC ECHINODERMATA .

OF THE

UNITED STATES

BY

WILLIAM BULLOCK CLARK

WASHINGTON

GOVERNMENT PRINTING OFFICE' 

1893

CONTENTS.

* Page.

Letter of transmittal.............................................« ............ 9

Preface ..................................................................... 11

Introduction ................................................................. 13

Bibliography ............................................................... 15

Systematic review .......................................................... 21

Crinoidea............................................................... 21

UiutacrinidiB ................................................... 21

Apiocrinidte .................................................... 24

Peutacriuidu) ................................................... 25

Asteroidea.............................................................. 29

0 p h iurid oe...................................................... 29

Sfcelleridie ...................................................... 31

Echinoidea ............................................^................ 33

Euechinoidea......................................................... 33

Regulares .......................................................... 33

CidaridsB ....................................................... 33

Salenidte ....................................................... 40

Diadematidro .................................................... 44

Echiuidae....................................................... 54

Irregulares ......................................................... 58

Echinoconidie .................................................. 58

CassidulidiB .................................................... 59

HolasteridiB .................................................... 74

Spatangidie..................................................... 78

Doubtful and unrecognized species ...................................... 92

Geological distribution ..................................................... 94

Catalogue of specific names employed by writers upon the Mesozoic Eclmiodennata of the United States.............................................. 95

Plates ...................................................................... 103

Index ....................................................................... 205

ILLUSTRATIONS.

Page. 

Plate I. Uintacrinns socialis Grinnell................................. 106

II. Uintacrinus socialis Grinnell--.-....-......-...-...---..-...-. 108

III. Bourgueticrinus alabamensis deLoriol; Pentacrinus asteriscus 

Meek & Haydeu; Pentacrmus Bryaui Gabb; Peutacrinus 

Whitei Clark................... '..-.....-. ........... HO

IV. Opldoglypbabridgerensfs (Meek); Ophioglypha texana Clark. 112

V. Goniaster mammillata Gabb; Asterias dubiam Whitfield...... 114

VI. Ciclads taylorensis Clark; Cidaris caliibrnicus Clark; Cidaris

spleiidens Morion; Cidaris Walcotti Clark*.................. 116

VII. Cidaris texanns Clark; Leiocidaris hemigranosns (Sliumard).. 118 

VIII. Leiocidaris hemigranosuS (Sliumard) ......................... 120

IX. Leiocidaris hemigranosus (Sliumard) ......................... 122

X. Saleuia texaiia Credner ...................................... 124

XI. Salenia tumidula Clark; Salenia bellula Clark................ 120

XII. Hemicidaris iutuniescens Clark; Pseudodiadema Emersoni

Clark...................................................... 128

XIII. Pseudodiadema diatretum (Morton); Pseudodiadema texanum

(Roemer) ........:......................................... 130

XIV. Pseudodiadeina texanum (Roemer) ........................... 132

XV. Diplopodia texanum (Roemer) ............................... 134

XVI. Diplopodia texanum (Roemer); Diplopodia Hilli Clark ....... 136

XVII. Coptosoma Mortoui (de Loriol)............................... 138

XVIII. Coptosoma speciosum Clark; Goniopygus Zitteli Clark....... 140

XIX. Gouiopygus Zitteli Clark .................................... 142

XX. Psamrnechinus ciugulatus Clark.............................. 144

XXI. Pedinopsis Pondi Clark ...................................... 146

XXII. Pedinopsis Pondi Clark...................................... 148

XXIII. Stomechinus Hyatti Clark; Holectypus plan atus Roemer ..... 150

XXIV. Pyrina Parryi Hall...................... ..^.................. 152

XXV. Botriopygus alabameusis Clark .............................. 154

XXVI. Echinobrissus expaiisus Clark; Echinobrissus texanus Clark.. 156

XXVII. Trematopyguscrucifer (Morton); Catopygns o\riformis Conrad;

Catopygus pusillus Clark ................................... 158

XXVIII. Cassidulus florealis (Morton) ................*................. 160

XXIX. Cassidulus sequoreus Morton ................................. 162

XXX. Cassidulns micrococcus Gabb ................................ 164

XXXI. Cassidulus subquadratus Conrad ............................. 166

XXXII. Cassidulus subconicus Clark ................................. 168

XXXIII. Cassidulus porrectus Clark................................... 170

XXXIV. Cassidulus porrectus Clark .... . r ............................. 172

XXXV. Cassidulus porrectus Clark; Cassidulus Stantoni Clark....... 174

XXXVI. Auaucbytes ovalis Clark ..................................... 176

7
8 ILLUSTRATIONS.

Page.

Plate XXXVII. Cardiaster cinctus (Morton) ................................ 178

XXXVIII. Holaster simplex Shumard ................................. 180

XXXIX. Holaster simplex Shumard; Euallaster texauus (Roemer)... 182

XL. Euallaster bbliquatus Clark................................ 184

XLL Epiaster elegans (Shumard) ................................ 186 .

XLII. Epiaster elegans (Shumard) ................................ 188 j~

XLIII. Epiaster elegaits (Shumard); Epiaster Whitei Clark.... .1.. 190

XLIV. Epiaster Whitei Clark ..................................... 192

XLV. Hemiaster parastatus (Morton)............................. 1 94

XLVI. Hemiaster Stella (Morton); Hemiaster ungula (Morton) .... 196

XLVII. Hemiaster texanus Roemer................................. 198

XL VIII. Hemiaster Humphreysanus Meek and Hay den; Hemiaster

Dalli Clark.............................*................- 200

XLIX. Hemiuster californicus Clark; Hemiaster Calviui Clark..... 202

L. Linthia tumidula Clark ..................................... 204
LETTER OF TRANSMITTAL.

DEPARTMENT OP THE INTERIOR, 

UNITED STATES GEOLOGICAL SURVEY, 

DIVISION OF MESOZOIC INVERTEBRATES,

Washington, D. G., October 15, 1891.

SIR : I herewith transmit the manuscript of a memoir on the Mesozoic 

Echinodermata of the United States by Dr. William B. Clark, which 

you authorized him to prepare as a part of the work of the division of 

the Survey in my charge. I recommend that it be published as a bulletin of the Survey.

/Very respectfully,

C. A. WHITE,

Geologist in charge. 

Hou. S. W. POWELL,

Director U. S. Geological Survey.

PREFACE

The present bulletin on the Mesozoic Echinoderniata of the United 

States is the first of a series of reports on American fossil radiates. 

The material for a review of the Oenozoic Echinodermata has already 

been collected, and the results of that work will be shortly added.

The investigation of the Mesozoic Echinodermata, first undertaken at 

the request of Dr. C. A. White, was intended to include only the material 

in the possession of the U. S. National Museum, but the necessity for 

wider comparisons and a general treatment of American species became 

apparent as the work advanced. The larger collections in other institutions were accordingly drawn upon, and as a result the number of 

new forms has been greatly increased, while misconceptions that have 

hitherto existed as to the limitations of many of the earlier species have 

been rectified.

Much poor material that indicates other and new species has been 

ignored in this review, so that farther collections will doubtless largely 

increase the number of American forms.

The writer is under great indebtedness to Prof. Bobert T. Hill for information in regard to the geological range and localities of many of the 

Texan species and for the loan of a large amount of material. Further, 

the writer desires to extend his thanks to Prof. Augelo Heilprin, of the 

Academy of Natural Sciences of Philadelphia, Prof. li. P. Whitfield, of 

the American Museum of Natural History, New York, Prof. Alpheus 

Hyatt, of Boston, Prof. O. C. Marsh, of New Haven, Mr. G. Wolf Hoistein, of Texas, Dr, G. Hambach, of St. Louis, Prof. Samuel Calvin, of 

the University of Iowa, Mr. E. T. Durable, State Geologist of Texas, 

Mr. E. J. Pond, of Washington, Mr. F. A. Sampson, of Sedalia, Missouri, 

and others, for the opportunity to use the important collections in their 

possession.

The writer is under the greatest obligations to Mr. C. E. Keyes, who 

has executed the very complete and accurate series of structural drawings, and whose extensive knowledge of the Echinodermata gives to the 

other illustrations prepared by him an especial value for determinative 

purposes. The author is also indebted to Mr. H. C. Hunterfor the care 

he has shown in the preparation of the drawings intrusted to him.

11

THE MESOZOIC ECHfflODERMATA OF THE UNITED

STATES.

BY WILLIAM BULLOCK CLARK.

INTRODUCTION.

The need of arevision of American systematic paleontology is nowhere 

more apparent than in the snbkingdom of the Echinoderinata. The valuable contributions of Wachsmuth and Springer upon the Paleozoic 

Crinoidea have largely covered the field for that division, while as yet 

nothing exhaustive has been attempted for the Mesozoic and Cenozoic. 

The value of the Echinodermata in the later horizons may not be so great 

as in the earlier, yet many important forms of wide geological and geographical range are found in both the Mesozoic and Cenozoic.

The reports of Morton upon Atlantic Coast species and of Boenier and 

Shumard upon Texan types are among the most important publications 

upon North American Mesozoic Echinodermata, but the articles are in 

each case difficult of access to the student and the,results recorded 

Avholly inadequate for present systematic or stratigraphical requirements.

In previous discussions of North American Echinodermata no attention has been paid to the South American forms, so that much confusion exists as to the true relations of the two faunas. Very little is 

known of the geographical range of the various species, but that many 

of the North and South American forms described under different names 

are identical is beyond doubt. When more exhaustive collections have 

been made and comparisons instituted, this similarity of echiuoderm 

faunas in the two continents will be made apparent. The present poor 

descriptions and meager figures afford a very inadequate basis for such 

a study.

The identity of American with European species seems doubtful, although a few forms present characters that closely ally them.

In the succeeding pages is presented a complete bibliography of 

works on North American Mesozoic Echinodermata, and of certain 

others that deal with closely related forms.

In the systematic review that follows, and that constitutes the major 

portion of the report, descriptions of moderate length are accorded the

13
14 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [6ULL.97.

different species. It has been deemed sufficient to present simply those 

characteristics that are necessary for an accurate determination of the 

forms, omitting many of the minute though interesting details of 

structure. A table is given showing the geological range of the different American Mesozoic species. In conclusion an index to the various 

terms employed by those who have written on the Mesozoic Echinodermata of the United States is presented.

An attempt has been made to very fully illustrate all'the species. 

Many of the details of structure, not recorded in the descriptive portions^ 

of the report, are shown on the various figures.
CLABK.] BIBLIOGRAPHY.

BIBLIOGRAPHY.'

1829.

MORTON, S. G. Note: Containing a notice of home Fossils recently discovered in 

New Jersey. Philadelphia Acad. Nat. Sci. Jonr., 1st ser., vol. 6, pp. 120-129.

1830.

MOKTON, S. G. Synopsis of the Organic Remains of the Ferruginous Sand Formation

of the United States, with Geological Remarks. Amer. Jour. Sci., 1st ser.,

vol. 17, pp. 274-295. 

MOKTON, S. G. Synopsis of the Organic Remains of the Ferruginous Sand Formation

of the United States, with Geological Remarks. Amer. Jour. Sci., 1st ser.,

vol. 18, pp. 243-250, pis. 1-3. 

MOKTON, S. G. Additional Observations on the Geology and Organic Remains of

New Jersey and DelaAvare. Philadelphia Acad. Nat. Sci. Jour., 1st ser., vol.

6, pp. 189-204.

1833.

MORTON, S. G. Supplement to the "Synopsis of the Organic Remains of the'Ferruginous Sand Formation of the United States," contained in volumes xvn, 

and xviii of this Journal. Amer. Jour. Sci., 1st ser., vol. 23, pp. 288-294, 

2 pis.

MOKTON, S. G. Supplement to the "Synopsis of the Organic Remains of the Form- - 

ginous Sand Formation of the United States." Amer. Jour. Sci., 1st ser., 

vol. 24, pp. 128-132, pis. 9,10. 

1834.

MORTON, S. G. Synopsis of the Organic Remains of the Cretaceous Group of the 

United States.

1835.

AGASSIZ, L. Prodrome d'une monographie des Radiares on Echinodermes (1834). 

Neuchatel Soc. Sci. Nat., Mem. I, pp. 168-199.

1837.

DESMOUI.INS, C. Etudes sur les fichinides. ; -*.

1840.

AGASSIZ, L. Catalogus systematicus Ectyporum Echinodermatum fossilium.

LEA, I. Notice of the Oolitic Formation in America, with Descriptions of some of its

Organic Remains. Amer. Phil. Soc. Trans., 2d ser., vol. 7, pp. 251-260, pis.

8-10. 

NYST, H., and GALEOTTK, H. G. Description de quelques fossiles du calcaire jurassique

de Tehuacan au Mexique. Brnxelles Acad. Sci., Bull. 7, pte. 2, pp. 212-221,

2 pis.

1 The literature referred to in the accompanying list includes only those works in which Korth American species are directly referred to, or in which identical or related forms are described.
16 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [BULL.97.

1841.

MORTON, S. G. Descriptions of two new species of fossils from the Lower Cretaceous 

strata of New Jersey. Philadelphia Acad. Nat. Sci. Proc., vol. 1, pp. 131, 

132.

1842.

MORTON, S. G. Description of some new species of Organic Remains of the Cretaceous Group of the United States. Philadelphia Acad. Nat. Sci. Jour., 1st 

ser., vol. 8, pp. 207-215.

MORTON, S. G. Tabular view of the Organic Remains hitherto discovered in the 

Cretaceous Strata of the United States. Philadelphia Acad. Nat. Sci. Jour., 

1st ser., vol. 8, pp. 216-227.

D'ORBIGNY, A. Voyage dans I'Ame'rique meYidionale. Paleontologie. Text in vol. 

3; plates in vol. 8.

D'ORBIGNY, A. Coqullles et fichinoderines fossiles de Coluuibie, recueillies par 

M. Boussingault.

1844.

FORBES, E0\v. Ou the fossil shells collected by Mr. Lyell from the Cretaceous 

Formations of New Jersey. Geol. Soc. London Proc., vol. 4, pp. 307-310.

1846-'47.

AGASSIZ, L. arid DESOR, E. Catalogue raissoun6 des families, des genres, et des 

especes de la classe des Echiuodermes. Aim. Sci. Nat. (Zool.), vol. 6, pp. 305- 

374; vol. 7, pp. 129-168; vol. 8, pp. 5-35, 355-381.

1848. 

BRONN, H. G. Index Palaeontologicus.

* 1849.

ROEMER, F. Texas, mit besouderer Rticksicht auf Deutsche Auswanderung und die 

physischen Verhatnisse des Landes nach eigener Beobachtung geschildet\t. 

Mit einem uaturwissenschaftlichen Auhange und einer topographisch-geognostischen Karte von Texas.

1850.

D'ORBIGNY, A. Prodrome de Pale~ontelogie. Terrains Cre'tace's. Senouien. Echinodermes, n, pp. 268-275.

CONRAD, T. A. Description of one new Cretaceous and seven new Eocene fossils. 

Philadelphia Acad. Nat. Sci. Jour., 2d ser., vol. 2, pp. 39-41.

RAVENEL, E. On the Recent Squalidse of the Coast of South Carolina, and Catalogue of the Recent and Fossil Echinoderms of South Carolina. Ainer. 

Assoc. Adv. Sci. Proc., vol. 3, pp. 159-161.

1850-'60.

D'ORBIGNY, A. Paleontologie Fraucaise. Description des Auimaux Inverte'bre's. 

Terrain Cre'tace'. fichinides. Tome 7.

1851.

BAYLE and COQUAND. M6moire sur les fossiles secondaires recueillis dans le Chili 

par M. Ignace Domeyko. Geol, Soc, France, Mem. n, 4, pp. 1-47, pis. 1-8.
CLARK.] BIBLIOGRAPHY. 17

1852. 

ROEME"R, F. Die Kreidebildungeri vou Texas nucl ihre organischen Einschliisse.

1853.

SHUMARD, B. F. Paleontology of the Exploration of the Red River of Louisiana in 

the year 1852, by Capt. R. B. Marcy, U. S. Army, pp. 199-211.

GIEBEL, C. G. Beitrag zur Palteontologie des Texanischen Kreidegebirges. Jahresber. d. naturw. Vereins in Halle (1852), pp. 358-375, pis. 6, 7.

1854.

D'ORBIGNY, A. f Note rectificative sur divers genres d'Echinoides. Rev. et. Mag. 

Zool., vi, pp. 16-28.

1855.

SCHIEL, JAMES. List and Description of Organic Remains collected during the 

Exploration of the Central Pacific R. K. line, 1853-;54. Pacific Railroad 

Reports, vol. 2, pp. 108-109, pis. 1^.

1857.

HALL, JAMES. Geology and Paleontology of the Boundary. U. S. and Mex. Bound. 

Surv., vol. 1, pt. 2, pp. 101-174.

MEEK, F. B. and HAYDEX, F. V. Description of new Species and Genera of Fossils, 

collected by Dr. F. V. Hayden in Nebraska Territory, under the direction 

of Lieut. G. K. Warren, U. S. Topographical Engineer; with some remarks 

on the Tertiary and Cretaceous formations of the Northwest, and the parallelism of the latter with those of other portions of the United 'States and 

Territories. Philadelphia Acad. Nat. Sci. Proc., vol. 9, pp. 117-148.

1858.

MARCOU, JULES. Geology of North America.

DESOR, E. Synopsis des Jfichinides fossiles.

MEEK, F. B. and HAYDEN, F. V. Descriptions of New Organic Remains collected 

in Nebraska Territory in the year 1857 by Dr. F. V. Hayden, Geologist to 

the Exploring Expedition under the command of Lieut. G. K. Warren, Topographical Engineer., U. S. Army, together with some remarks on the geology 

of the Black Hills and portions of the surrounding country. Philadelphia 

Acad. Nat. Sci. Proc., vol. 10, pp. 41-59.

1859.

»

GABB, WM. M. Catalogue of the Invertebrate Fossils of the Cretaceous Formation 

of the United States, with references. Special publication of the Academy 

of Natural Sciences of Philadelphia.

1860.

SHUMARD, B. F. Observations upon the Cretaceous Strata of Texas. St. Louis

Acad. Nat. Sci., Trans., vol. 1, pp. 582-590. 

SHUMARD, B. F. Descriptions of new Cretaceous fossils of Texas. St. Louis Acad.

Nat. Sci. Trans., vol. 1, pp. 590-610. 

CONRAD, T. A. Descriptions of New Species of Cretaceous and. Eocene fossils of

Mississippi and Alabama. Philadelphia Acad. Nat. Sci. Jour., 2d ser., vol.

4, pp. 275-298. 

GABB, WM. M. Descriptions of New Species of American Tertiary and Cretaceous

Fossils. Philadelphia Acad, Nat, Sci. Jour.. 2d ser.; vol. 4, pp. 375-416, Bull. 97 3 ' - -*- ' 
18 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [HULL. 97.

GABB, WM. M. Description, of New Species of Cassidulus from the Cretaceous

formation of Alabama. Philadelphia Acad. Nat. Sci. Proc., vol. 12, p. 519. 

PHILIPPI, R. A. Viaje al Desierto dc Atacama. (German and other translations.)

1862-'67.

COTTEAU, G. Pale~ontologie Francaise. Description desAnimanx In vert<Sbr6s. Terrain Cre"tace~ Echinides. Tome vn.

1864.

MEEK, F. B. Check List of the Invertebrate Fossils of North America. Smith. 

Misc. Coll., vol. 7 (177). '

1865. ^

MEEK, F. B., and HAYDEN, F. V. Paleontology of the Upper Missouri. Smithsouian 

Contrib. Knowledge, vol. 14 (172),

1868.

COOK, GEORGE H. Common and characteristic fossils of the three marl beds

Geology of New Jersey, pp. 374-377. 

CONRAD, T. A. Synopsis of the Invertebrate Fossils of the Cretaceous Formation of

New Jersey. Geology of New Jersey, Appendix A, pp. 721-731.

1869.

GABB, WM. M. Descriptions of Cretaceous Fossils from Mexico. Geol. Surv. of 

California, Paleontology, vol. 2, sec. 3, pp. 255-276.

1870. '

CREDNER, H. Die Kreide von New Jersey. Zeifcsch. der Deutsch. Geol. Gesells. l 

xxn, pp. 191-251. ^

1871. \

MARSH, 0. C. On the geology of the eastern Uintah Mountains. Amer. Jour. Sci., j 

3d ser., vol. 1, pp. 191-198. V

1875. ' <

WHITE, C. A. Paleontology. U. S: Goog. Survs. West 100th Meridian, vol. 4, pt. 1. 

CRKDNEK, G. R. Ceratites fastigatus und Salenia texaua. Zeitsch. f. d. Ges. Naturw. XLVI, pp. 105-116, PI. v, Figs. 1-6.

1876. 

GRIN NELL, G. B. On a new Crinoid from the Cretaceous formation of the West.

Amer. Jour. Sci., 3d ser., vol. 12, pp. 81-83. 

GABB, WM. M. Note on the Discovery of Representatives of Three Orders of Fossils

new to the Cretaceous Formation of North America. Philadelphia, Acad.

Nat. Sci. Proc., vol. 28, pp. 178, 179. 

GABB, WM. M. Notes on American Cretaceous Fossils, with descriptions of some New

Species. Philadelphia, Acad. Nat. Sci. Proc., vol. 28, pp. 276-324. 

GABB, WM. M. Description of a Collection of Fossils made by Dr. Antonio Raimondi in Peru. Philadelphia, Acad. Nat. Sci. Jour., 2d ser., vol. 8, pp.

262-336. 

LORIOL, P. DK. Note sur qjielques .especes nouvelles appartenant a la classe des

Echinoderines. Soc. de Phys. et de Hist. Nat. de Geneve, Me~in. xxiv, pp.

659-673.
CLARK.] BIBLIOGRAPHY. 19

MEEK, F. B. Note on the new genus, Uintacrimis Griunell. U. S. Geol. anil Geog.

Surv. of the Territories, Bull., vol. 2, pp. 375-378. 

MEEK, F. B. Report on the Paleontological Collections of the Expedition. Expl.

Great Basins of Utah by Simpson, Appeiuax J, pp. 337-373. 

"MEEK, F. B. Invertebrate Paleontology. U. S. Geological Surv. of the Territories,

vol. 9.

1877.

HAGUE, A., and EMMONS, S. F. Descriptive Geology. U. S. Geological Expl., 40th

Parallel, vol. 2.

WHIT FIELD, B. P. Preliminary Report on the Paleontology of the Black Hills. t 

HALL JAMES, and WHITFIELD, R. P. Paleontology. U. S. Geological Expl., 40th

Parallel, vol. 4, pt. 2, pp. 199-302.

1878.

ScriLtJTER, C. Ueber oinige astylide Crinoiden. Zeitschr. der Deutsch. Geol.

Gesells. xxx, pp. 28-66, Pis. 1-4. 

KING, C. Systematic Geology. U. S. Geological Expl., 40th Parallel, vol. 1.

1879.

PEALE, A. C. Jura-Trias Section of Southeastern Idaho and Western Wyoming. U. 

S. Geol. and Geog. Surv. of the Territories, Bull., vol. 5, pp. 119-123.

1880.

WIIITFIELB, E. P. Paleontology of the Black Hills of Dakota. U. S. Geol. and 

Geog. Snrv. of the Rocky Mt. Region. In Report on the Geology and Resources of the Black Hills of Dakota.'

1881.

STEINMANN, G. Zur Kenutniss der Jura-und Kreideforrnation von Caracoles (Bolivia). Neues Jahrb. f. Miu. Geol. u. Pal., Beilageband i, pp. 239-301, Pis. 

9-14.

STEINMANN, G. Ueber Tithon und Kreide in den peruauischen Anden. Neues 

Jahrb. f. Min. Geol. u. Pal., Bd. 11, pp. 130-153, Pis. 6-8.

1882.

BE LOHIOL, P. Description of a new species of Bourgueticrinus. Cincinnati, Soc. 

Nat. Hist. Jour., vol. 5,-p. 118, PI. v. Figs. 1, U.

- 1883.

WHITE, C. A. Contributions to Invertebrate Paleontology, No. 2. Cretaceous Fossils of the Western States and Territories. U. S. Geol. and Geog. Surv. of 

the Territories, 12th Aun. Rept. for 1878, pt. 1, pp. 5-39, pis. 11-18.

» 1887.

HILL, ROBT. T. The Texas Section of the American Cretaceous. Arner. Jour. Sci.,

3d set., vol. 34, pp. 287-309. 

BE LORIOL, P. Notes pour servir a Pe'tudea des e"chiuodernies. Recueil Zoologique

Suisse. torue iv, pp. 365-407, pis. 15-18.

1888.

ROEMER, F. Macraster, eine neue Spatangoiden^Gattung aus der Kreide vori Texas. 

Neues Jahrbuch fur Min. Geol., und Pal., Bd. i, pp. 191-195.
20 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [HUM,. 97.

WHITE, C. A. Contributions to the Paleontology of Brazil; comprising descriptions 

of Cretaceous Invertebrate Fossils, mainly from the provinces of Sergipe, 

Pernambuco, Para, and Bahia. Archivoa do Museu Nacional do Rio de 

Janeiro, vol. vn, pp. 1-273, Pis. i-xxvu.

1890.

COTTEAU, M. Note sur quelques Echinides du terrain cre"tace" du Mexique. Geol. 

Soc. France Bull, in, 18, pp. 292-299, pis. 1, 2.

1891.

CLARK, WM. B. A Revision of the Cretaceous Echinoidea of North America. Johns 

Hopkins University Circulars, No. 87, pp. 75-77.

. 1892.

GREGORY, J. W. The relations of the American and European Echinoid faunas. 

Geol. Soc. America Bull., vol. 3, pp. 101-108.
. SYSTEMATIC REVIEW.

CRINOIDEA. 

UINT ACRINID.ZE.'

Calyx unsymmetrical, without column. Basis mouocyelic. Basals' 

five,inclosing acentro-dorsalplate. Eadials 5x3. Interradialsnumerous, the lowest between the second radials. Arms 5x2, very long, 

with pinnules.

f? 

UrNTACRINUS Grinnell.

UiNTACRiNUS SOCIALIS Grinnell. 

Plate i, Figs, la-c; Plate n, Figs. la-e.

Uintacrinus socialis Grinnell, 1876. Amer. Jour. Sci., 3d ser., vol. 12, pp. 81-83, PI.

iv, Figs. l-2b. 

Uintacrinus socialis Meek, 1876. U. S. Geol. and Geog. Survey of the Territories,

Bull. vol. 2, pp. 375-378, Figs. A-B.

Determinative characters. Calyx subglobose, composed of numerous 

thin, slightly convex plates, joined together by channeled sutures and 

without distinct surface markings. Column wanting. Basis composed 

of a small pentagonal centro-dorsal plate, surrounded by a circle of five 

small similar basals. Encircling the pentagonal base and alternating 

with the basals are five large radials, hexagonal in outline and wider 

than high. Succeeding the primary radials are secondary and tertiary 

radials, the latter axillary in form. The primary radials alone are in 

contact, the others being separated by interradials. Succeeding the 

radials are several distichals, which gradually change to true rounded 

brachials, forming ten long arms. Between the distichals are two 

large interdistichals, situated one above the other. From the second 

distichal, which is axillary in form, a row of plates diverges interradially, alternating with similar plates from the same distichal of the 

adjacent area. From the fourth distichal a like row of plates diverges 

radially, alternating with similar plates from the same distichal of the 

other half of the same area. Higher up other rows diverge both radially

1 Thofamilyof theUintacrinidte, as characterized byvon Zittelinhis "HandbuchderPaleontologie," 

includes only two species, Uintacrinus socialis Grinnell, from the Cretaceous of Utah and Kansas, 

and V. we»t/alicua Schliiter from the Cretaceous of Westfalia. The genera Uintacrinus and Marsupites alone among Mesozoic types afford points for comparison with the Paleozoic crinoids. 

Ueumayr in "Die Stamme des Thierreiches " considers the difficulty of bringing them into a consistent 

classification with the other crinoids but suggests several points of relationship between Uiutacriuus 

and the Ichthyocrinidte.

21
22 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [BUU,. 97.

and interradially until true pinnules are developed on the free brachials. 

The brachials are united either by articulation or sizygial suture, in 

the latter case the line of union often becoming obliterated. The interradial plates, eight or nine in number, form a rounded, slightly 

elevated shield-like area, surrounded above by the alternating rows of 

plates that diverge from the second distichal.

Dimensions. Calyx: height, 2 inches5 breadth, 2£ inches. Arms: 

length, 20 inches (?).

Description. The first specimen of this species was collected by 

Prof. O. C. Marsh in 1870 from the Cretaceous of the Uinta Mountains 

of Utah and by him compared with Marsupites of the English chalk. 1 

Subsequently other specimens were obtained from Kansas, and in 1876 

were described by Mr. G. B. Griunell, an assistant to Prof. Marsh at 

that time, under the name of Uintacrinus socialis. Prof. F. B. Meek, 

who had already in his possession similar material, added, in the Bulletin of the U. S. Geological and Geographical Survey of the Terrtories, 

descriptions of certain points in the structure not mentioned by Grinuell.

All the specimens hitherto collected are much compressed, so that 

the original form is with difficulty determined. In general, on any 

single specimen only the plates of one side are preserved sufficiently . 

well for identification.

The calyx is subglobose, with ten long, simple arms extending from 

the upper side (PI. i, Fig. 1ft). The plates are thin, slightly convex, 

and joined together by simple, though well marked, sutures, that are 

generally slightly channeled. The calyx is without column or stalk, 

and belongs to the class of "free" forms.

The basis is composed of a centro-dorsal plate, surrounded by five 

basals. The centro-dorsal ,plate is doubtfully visible upon only a 

single specimen. Judging from the problematical portion of the plate 

exposed, and the shape of the lower edges of the basals, it must be 

small and pentagonal in form. Its presence was not noted by either 

Grinnell or Meek, upon the specimens examined by them. The five 

basals, also undescribed by previous writers, encircle the centro-dorsal 

plate (PI. it, Figs, la, 1ft). They rest with one side against the latter 

and terminate in a sharp angle above. The whole basis forms a nearly 

perfect pentagon, which is slightly depressed where the line of juncture of two adjacent basals reaches the edge. Five large primary 

radials surround the basals and alternate with them. They'are six 

or seven sided, the latter occurring when the edge toward the basis 

is broken by an angle into two portions. These plates are wider than 

high, and come in contact with one another only in the lower portion 

of each side. The upper parts are separated by the interradial area, 

as are the secondary and tertiary radials that succeed the primary. 

The secondary radials are smaller than the primary, and are separated 

by horizontal suture lines from. them. The tertiary radials are axil1 Amer. Jour. Sci., 3d ser., vol. 1, 1871, p. 195.
TJINTACRINUS SOCIALIS. 23

lary, bearing two large distichals that come in contact only along a 

portion of their lateral margins (PI. I, Fig. Ic). Succeeding the primary 

distichals are four others of large size and varying shape, beyond which 

the plates rapidly decrease in size and change to true brachials (PI. I, 

Fig. Ic).

In the angle between the larger distichals of each radial series are 

two large inter distich al plates. The lower of these comes in contact 

with the primary distichals in the angle formed by the upper portions 

of the lateralomargins of those plates. It likewise touches the sides of 

the second and a portion of the third distichal. The upper interdistichal rests with horizontal edge upon the lower, and is embraced between the upper portion of the third disticlials and the. lower portion 

of the fourth, ending above with angular margin between the modified 

plates that branch from the fourth distichals, to be presently referred to.

The second distichals are axillary and support interradially rows of 

plates, the first of each row separated from one another by the iiiterradials (PI. I, Fig. la). The first plates are smaller than the second of 

the same row, which meet with a vertical suture and slightly-overlap, 

a character which becomes more pronounced higher in the series, so 

tliat true alternation results. Beyond the third plate a rapid reduction 

in size of plates takes place. Ten to twelve plates have been recognized in each row. &

From the fourth distichals, which are likewise axillary, similar rows 

diverge radially (PI. I, Fig, Ic). From the fifth distichals are other 

rows interradial in position, while the seventh again bear radial 

branches. These rows gradually grow smaller and as the brachials 

become movable appear as pinnules. The lower rows become incorporatedin the calyx, and as they are immovable have become modified 

for the position they occupy.

The interradials are eight, nine, or more in number and form an ele-. 

vated, shield-like area, each plate likewise showing a slightly convex 

surface (PI. i, Fig. 1ft). The arrangement of the plates does not 

vary; seven in an oval band inclose the eighth, or eighth and ninth, 

according to the number of interradials. The lower interradial occupies 

the angle between the upper portions of the lateral margins of the 

primary radials and likewise separates the secondary radials. The two 

upper interradials occupy the angle formed by the branches from the 

second distichals and the distichals themselves. The four other inter - 

radials .of the outer band lie two on each side between the lower interradial and the upper pair of plates. The lower two of these four are 

in contact, while the upper two arc separated by the inner plate or 

plates. In contact with the four plates are the secondary and tertiary 

radials and the first and second distichals. The inner plate is more frequently replaced by two smaller ones irregular in outline and position.

The brachial plates are the continuation of the distichals and form 

ten simple arms. They gradually assume a half-round, horseshoe-
24 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [BULL. 97.

shaped outline, the depression on the inner surface increasing until a 

well-marked ambulacral farrow is produced. The plates are likewise 

perforated a short distance in front of the same. The plates are united 

in two ways, by articulation (PL n, Fig. 3 e) and by sizygial suture (PI. rr, 

Fig. 1$), the former producing a movable joint, the latter uniting adjacent plates immovably. Eows of pinnules are developed on the inner 

surface of the arms alternately from opposite sides, each row branching from the epizygale, where the sizygial suture is observed (PI. n, 

Fig. Ic).

The arms attain very great length. Grinnell mentions a specimen 

examined by him where the arms measured 8 inches, and one examined 

by the writer was very nearly as long. Grinnell thinks the arms may 

reach 2 feet in length.

Related forms. The present species is closely allied to Uintacrinus 

tvestfaliens, described by Schliiter 1 in 1878 from the Upper Cretaceous 

(Senonian) of Reeklinghausen, in Westphalia. It is the only other species of this genus thus far described, so that a statement of the affinities of the two forms is important. In the composition of the basis the 

two species are very nearly identical. The radials and distichals show 

very slight differences, but the brachials in U. socialis are decidedly 

broader than in U. westfalicus. In the number and arrangement of the 

interradials the most marked difference is manifested. In U. socialis 

seven interraclial plates encircle the eighth, or eighth and ninth, as the 

case may be, while in U. ivestfaliens the interradials are five in number, 

all of which come in contact with plates of other areas. Several minor 

differences appear in the rows of small plates that branch from the 

distichals. Otherwise, however, there is a marked similarity in the 

arrangement and form of the several plates. In general outline the 

two species are very similar.

Locality and geological horizon. The first specimen was found on the 

slopes of the Uinta Mountains, in Utah, by Prof. Marsh, associated 

with Ostrea congesta Con., a typical Cretaceous form. . Later, others 

were found in Kansas, associated with Odontornithes, Pterodactyls, 

and mosasauroid reptiles, likewise characteristic of the Cretaceous. 

Meek assigns the species to the Niobrara Group, a horizon of the upper 

Cretaceous.

Collections. Peabody Museum, New Haven; U. S. National Museum.

APIOCRINID2E.

Calyx regular, composed of thick, articulated plates; basals five; 

radials 5 x 1-3. Exceptions frequent. Arms strong, numerously 

divided. Column long.

1 Zeitsclir. der Deutsch. geol. Gesells., xxx, 1877, pp. 55-63, PI. iv.
CLARK.] BOURGUETICRINUS ALABAMENSIS. 25 

BOUEGUETICELTOS D'Orbigny.

BOUEGUETICEINUS ALABAMENSIS de Loriol. 0

Plate in, Figs, la-c.

Bonrgueticrinus alabamensis de Loriol, 1882. Cincinnati Soc. Nat. Hist. Jour., vol. 

v, p. 118, PI. v, Fig. 1, la, 1Z>.

As it lias been impossible for the writer to obtain possession of the 

type of this species the description of de Loriol, as translated by Prof. 

S. A. Miller, is given verbatim: "This species is as yet known only 

by the basal cone which supports the calyx, and which is composed of 

several enlarging segments of the column surmounted by the basal 

plates. The height of the inverted coneis5mm ; the diameter of the 

basal plate is 3£Ilini , and that of the inferior segment of the column is 

3llim in its major axis. Its form is faintly swollen in the middle; the 

surface is smooth. The sutures are very indistinct, and it is a difficult 

matter to determine what was the height of the basal plate. The superior face of the cone carries five slender and comparatively elevated 

radiating ridges, which bound five deep depressions in which the basal 

pieces of the calyx were lodged; in the center an enlargement of the 

central canal constitutes the bottom of the, calyx cavity. The articular face of the lower joint of the column forming the inferior end of the 

cone is elliptical, but the length of its major axis does ijot, however, 

much exceed that of its minor axis. It .is, slightly concave and encircled by a feeble rim along the circumference line; the transverse articular ridge process is reduced to two elongated tubercles which proceed 

from the marginal rim. Central canal comparatively large."

Related forms. "Although this species is still very imperfectly 

known one can affirm that it is certainly distinct from Bourguetlcrinus ellipticHS Miller, by the much less swollen form of the basal cone, 

which is but slightly convex in outline, and by the facts that the lower 

segment of the cone is already elliptical and already possesses the rudiments of a transverse articular ridge. Furthermore, the radiating 

carinse are very much more salient, and consequently the depressions 

which they separate very much deeper. Finally, by its central canal 

being relatively much larger."

Locality and geological horizon. " Livingstone, Alabama, Eipley 

Group of the Cretaceous, or at the top of the'Eotten limestone."

Collection. Cincinnati Society of Natural History.

PENTACRINIDJE.

Calyx small, "composed of five basals and five radials with under - 

basals in one genus. The rays divide.from one to eight times. The 

stems bear verticils of cirri at intervals. Two joints are united by 

syzygy at each node, to the upper one of which the cirri are articulated.
26 THE ME8020IC EICHtNODERMATA OF UNITED STATES. [ftuLi,9T.

The internodes are traversed by five ligameutous bundles, which are 

interradially disposed, and give rise to a more or less petaloid figure 

on the joint-faces. No root nor radicnlar cirri." (P. H. Carpenter.)

PENTACRINUS Miller. 

PENTACRINUS ASTERISCUS Meek and Hayden. 

Plate in, Figs.

Pentacrinus asteriscns Meek and Hayden, 1858. Philadelphia Acad. Nat. Sci. Proc.,

vol. 10, p. 49. 

Pentacrinus asteriscus Meek and Hayden, 1860. Philadelphia Acad. Nat. Sci. Proc.,

vol. 12, p. 419.

Pentacrinus asteriscus Meek, 1864. Smith. Misc. Coll. (177), p. 27. 

Pentacrinites asteriscns Meek and Haydeu, 1865. Pal. Upper Missouri, Smith. Contr.

Knowledge (172), p. 67, PI. in, Fig. 2. 

? Pentacrinites asteriscns Whitfield, 1880. Geol. Black Hills of Dakota, p. 345, PI. in,

Figs. 1, 2.

Determinative characters. Calyx branching. Stem or column composed of small, pentagonal joints, rather thick,' that bear at intervals 

small rounded processes or cirri. The column joints are connected by 

crenated ridges arranged in pentapetalous form. The stein is perforated by a central canal.

Dimensions. Oolumn: breadth of joint, £-0 to % inch; length of joint, 

/o inch.

Description. This species was first described by Meek and Hayden in 

1858, in the- Proceedings of tne Academy of Natural Sciences of Philadelphia, from several fragments of the column. The calyx or arms are 

not known, and, as in the succeeding species, the distinguishing characteristics are confined entirely to the column joints. On the large slab 

figured by Meek and Hayden in the Paleontology of the Upper Missouri are several detached portions of the column 1 to 2 inches in 

length. The sutures are clearly marked and the nodal can be readily 

separated from the internodal joints. Of the latter, ten are plainly seen 

between two nodes on one fragment (PL in, Fig. 2 a), while in other 

instances the number seems .to be slightly greater. All the joints are 

rather thick (PL in, Fig. 2c). Five cirrus scars are found on each node 

in the reentering angles. Each node is joined to the underlying internode by syzygial suture, while the overlying plate is connected by 

creuulated ridges, as are = also the internodal plates themselves. The 

arrangement of these ridges is distinctly petaloid (PL in, Fig. 2 1). 

The reentering angles of the outer surface of the stem are not deep, so 

that the points of each star-shaped prolongation are short and broad.

The cirri are composed of small round joints that are longer than 

broad. They are joined, as far as' could be discerned, by simple sutures 

(PL m, Fig. 2d).

There is some doubt whether the form referred by Whitfield to P. 

asteriscns in the Geology of the Black Hills, and so figured and de-
CLARK.] PENTACRINUS WHITEI. 27

scribed, should be considered such. The reentering angles are much 

too deep. Unfortunately there is no side view of the plates.

Related forms. This species is wholly unlike the other American 

forms. In the first place, it is much smaller than P. Whitei, and P. 

Bryani and has a distinctly different form from P. Whitei with which 

it has been hitherto confounded. In P. Wliitei the reeu.teri.ug angle is 

made deeper and of different shape. Likewise tlie crenulatious of the 

petaloid area of the joints are differently arranged. The joints themselves are also relatively much thicker.

Locality, and geological horizon. Beported. by Meek and Hayden 1 

"associated with other Jurassic fossils from the southwest base of Black 

Hills, and opposite Ked Buttes, North Platte river," the former in Dakota, the latter in Nebraska. In the Check List of Invertebrate Fossils 

from the Jurassic, Meek also mentions Idaho and Colorado. Pealementions the occurrence of specimens in Idaho;

Collection. U. S. National Museum.

PENTACRINTJS WHITEI Clark. 

Plate in, Figs. 4a-c.

Pcntacrinites asteriscus White, 1875. U. S. Geog. Survs. Avest of 100th Meridian, vol.

4, 1875, p. 162, PI. xnr, Figs. 6a-b. 

IPeiitacriniteH asteriscns ( ?) Hall and Whitiield, 1877. U. S. Geol. Expl. 40th Parallel,

vol. 4, pp. 280, 281, PI. vi, Fig. 16. 

^Pcntacrinites asterisvus Whitfield, 1880. Geology of Black Hills of Dakota, p. 345,

PI. in, Figs. 1, 2. ,

Determinative characters. Calyx wanting. Column composed of 

large, thin, pentagonal joints that possess deep reentering angles. 

The creuulated ridges of the suture have a petaloid arrangement. Column perforated by central canal.

Dimensions. Column: breadth of joint, i to ^ inch; length of joint, 

aV inch.

Description. In the volume upon paleontology of the quarto publications of the U. S. Geological Surveys West of the One-Hundredth 

Meridian, Dr. White figures and refers a form to Pentacrinites asteriscns 

Meek and Hayden, that belongs evidently to another species. A comparison by the writer of the specimens figured by Meek and Hayden 

and by White shows that the differences are too great to permit 

their reference to the same species. The name P. Whitei is therefore suggested for the new form in honor of the distinguished scientist 

who has done so much to advance our knowledge of American 

Mesozoic geology and paleontology. As with P. asteriscus only portions of the column of P. Whitei have been discovered. The outer side 

of the column is furrowed by deep reentering angles producing five 

promineut*ridges at the salient angles. The joints are relatively thin, 

with rounded edges, so that the column does not appear compactly

1 Paleontology Upper Missouri, p. 67.
28 THE MESOZOIC EICHINODERMATA OF UNITED STATES. [BULL. 97.

formed from outward aspect (PI. in, Fig. 4c). A distinctly petaloid 

arrangement of the crenulated ridges is exhibited (PI. m, Figs. 4a, 4&).

Hall and Whitfield refer to Pcntacrinites asteriscus Meek and Hayden 

certain specimens collected by Hague in Nevada from " limestone of 

supposed Triassic age." There is some doubt as to the identity of this 

form, though the description and figures render it probable that it 

should be referred to P. Whitei.

The form figured and described by Whitfield from the Black Hills 

under the name P. asterisctis-is, on account of the deep reentering angles, 

to be probably associated with P. Whitei. No side view of the joints is 

given by which comparison may be made.

Related forms. Separated from P. asteriscus, with which it has been 

hitherto confounded, by its larger size, deeper reentering angles, and 

relatively much thinner plates.

Locality and geological horizon. The type specimens of this form are 

from the Jurassic of Salt creek and Diamond valley, Utah. 

. Collection. U. S. National Museum.

PENTAOBINUS BBYANI Gabb. 

Plate in, Figs. 3a-b.

Pentacrinus Bryani Gabb, 1876. Philadelphia Acad. Nat. Sci. Proc. ; vol. 28, p. 178, 

PL 5, Figs. 1, la, U.

Determinative characters. Calyx wanting. Column composed of 

moderately large, rather thick, pentagonal joints, with sharp reentering 

angles. The crenulated ridges are broadly petaloid and each area is 

rounded at its outer extremity. Column perforated by canal.

Dimensions. Column: breadth of joint, ^ inch; length of joint, 

J inch.

Description. Two small fragments of the stein of this form are 

described by Gabb in the Proceedings of the Academy of Natural 

Sciences of Philadelphia for 1876. As the only representative of this 

family reported from the American Cretaceous it possesses considerable interest. The column is composed of moderately large, thick joints, 

that in breadth reach quite one-quarter of an inch in diameter and 

about one-fifth of that in thickness. The broad rounded ridges at the 

salient angles of the pentagonal outline form a nearly unbroken line, 

while the furrow at the reentering angles is alternately depressed and 

elevated in successive joints." The edge of each joint is slightly rounded. 

The crenulated surfaces form five broad petaloid areas distinctly 

rounded at the outer extremities (PI. in, Fig. 3a) and unite near the 

inner edge of the reentering angles to form a double flat-topped ridge 

that reaches to the central canal, around which there is likewise a 

slight elevation. The creuulations are visible on the oute* surface of 

the column. The column is perforated by a central canal.

Related forms. As the only representative of this family in the
CLARK.] OPHIOGLYPHA BRIDGERENSIS. 29

Cretaceous, there is little among the American forms with ^which it 

may be compared, especially as the two Jurassic types previously 

described show marked differences in every particular.

Locality and geological horizon. The specimens described by Gabb 

and examined by the writer are from, the yellow limestone of Vincentown, New Jersey. The yellow limestone belongs to the middle 

marl bed and is upper Cretaceous.

Collections. Philadelphia Academy of Natural Sciences; Johns 

Hopkins University.

ASTEROIDEA. 

OPHITJRID^E.

Body star-shaped, with central disk and elongated arms, which are 

distinctly separated from the disk. The ainbulacral grooves are generally covered with plates.

OPHIOGLYPHA Lyman.

OPHIOGLYPHA BKIDGERENSIS (Meek).

Plate iv, Figs. 2a-6.

Ophioderma ? bridgerensis Meek, 1873. U. S. Geol. Surv. Territories for 1872, p. 475. 

Ophioderma ? bridgerensis White, 1883. U. S. Geol. and Geog. Surv. of the Territories for 1878, pp. 8, 9, PL 12, Fig. 12a.

Determinative characters. Disk composed of numerous small imbricating plates. Upper arm plates wider than long,' the outer angles 

sharp and extending between the side arm plates; which are slightly 

smaller. Under arm plates long and nearly rectangular in shape.

Dimensions. Diameter of disk, £ inch. Length of arm, £ inch. 

Width of arm near disk, -^ inch.

Description. The single specimen of this species thus far found is 

described in a foot-note to a list of specimens appended to the paleontological report of F. B. Meek in the Annual Keport of the U. S. 

Geological Survey, of the Territories for 1872, and redescribed and 

figured by Dr. C. A. White in the Annual Eeport for 1878 of the same 

organization. This specimen, which has been carefully examined by the 

writer, presents the upper surface of the disk and fragments of the five 

arms. Upon all but one fragment the upper and side arm plates are 

shown, while upon that a minute portion of the under surface of a single 

arm with the under arm plates and ambulacral openings is preserved.

The disk is described by Meek as "depressed, nearly circular, showing on the dorsal side ten ovate-sub trigonal radial plates/that are joined 

together over the inner ends of the arms, so as to form five pairs." A 

close examination of the specimen shows that the disk is made up of 

numerous small imbricating plates, and that the supposed division intp
30 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [BULL.97.

ten, as mentioned by Meek, may be explained by the fractured condition 

of the poorly-preserved specimen.

The arms are small, and are, as stated by Meek, perhaps £ inch in 

length, although none of them are preserved entire. The upper arm 

plates are Avider than long, and hexagonal in form (PI. iv, Fig. 2b). 

The outer angles are sharp, and are embraced between the upper portions 

of the side plates. The latter are slightly swollen, but are not shown 

in their entire length. The lower arm plates are poorly preserved, but 

so far as exhibited are long and narrow, nearly rectangular in shape 

and slightly swollen in their central portions.

Related forms. There is some doubt as to the generic position of this 

species. So many of the distinctive characters are wanting that a definite determination in that particular is quite impossible, but from the 

apparent structure of the disk, formed of numerous imbricating plates, 

its reference to Opliioglyplia, seems probable. The only other form, 

0. texana, has a somewhat smaller and differently constructed disk 

so far as can be discerned, and both the upper and under arm plates 

are of different shape.

Locality and geological horizon. This form is reported by Meek, from 

the "last foot of Bridger Peak, 4 miles north of Fort Ellis, Montana," 

associated with undeterminable species of the genera Oryphcva, Avicula, 

Inoceramus, Crassatella, Pholadomya, Turritella and Gyrodes, that denote the Cretaceous age of the strata.

Collection. U. S. National Museum.

OPHIOGLYPHA TEXANA Clark. 

Plate iv, Figs. la-c.

Determinative characters. Disk round; composition indistinct. Arms 

long, with wedge-shaped under arm plates about as wide as long; upper arm plates about twice as wide as long.

Dimensions. Diameter of disk, i inch; length of arm, 2 inches; 

width of arm at disk, ^ inch.

Description. The determination of this species is dependent upon 

three fairly well preserved forms that are grouped upon a single 

slab of limestone, all with the lower side exposed. The surface upon 

which they rest is considerably weathered, so that many of the details 

of structure have consequently suffered. The general form of the disk 

is preserved, though its composition can not be made out. In many instances the arm plates have disappeared, leaving only the skeletal pieces. 

Where preserved, the under arm plates are Avedge-shaped and about as 

wide as^long (PI. iv, Fig. Ic). The upper arm plates, which are slioAvn 

only as impressions upon the limestone, are nearly twice as \vide as 

long, and have their lateral edges rounded (PI. iv, Fig. 1&).

Related forms. Although tbis form can not with certainty be referred 

to Ophioglypha, it possesses, however, many points of similarity to
CLARK.] ASTERIAS DUBIUM. 31

the previous species, from which, on the other hand, it is separated by 

the different shape of the disk and of the under and upper arm plates.

Locality and geological horizon. The slab containing the specimens 

described is from the Denison beds of the Washita division of the Comanche series (Lower Cretaceous), C miles north of Fort Worth, on the 

banks of Fossil creek. It is found associated with Ostrea guadriplicata 

Shumard, Stearmia Robbinsi White, and Leiocidaris hemigranosus (Shumard).

Collection. U. S. National Museum.

STELLEKIDJE.

Body star-shaped or pentagonal, composed of a central disk and five 

prolongations of the same, called arms, that are portions of the body 

proper. Integument strengthened by calcareous plates irregularly arranged. Ambulacral furrow uncovered.

ASTEKIAS Linnaeus. 

ASTERIAS ? DUBIUM Whitfield. 

Plate V, Fig. 2.

Asteriasl dnlrinm Whitfield, 1877. Prelim. Rept. Pal. Black Hills, p. 15. 

Asterias^ duMum Whitfield, 1880. Geol. Black Hills of Dakota, pp. 344, 345, PL 3, 

Fig- 3.

Determinative characters.' Imperfectly preserved forms of small size, 

with slender flexuous arms, apparently covered superiorly with longitudinal rows of plates.

Dimensions. Length of arms, f inch to 1^ inches.

Description. This interesting but doubtful form is thus characterized 

by Whitfield: "The specimens are not in condition to -afford a full description of their specific characters. They are of small size, the rays 

being from, three-fourths of an inch to one and one-fourth inches long, 

measuring from the center of the body. The rays are slender and flexnous, most of them, being more or less curved in their direction and 

elevated along the middle, as shown on a gutta-percha cast taken in a 

natural mold of a group of three individuals. The upper surface is 

subangular, and in structure they are apparently composed of small 

uniform plates, placed in longitudinal rows. The center of the body 

or disk is marked by an obscurely pentangular depression on the upper 

surface. None of the specimens show the under side of the body or 

rays, so that the characters of these parts are entirely unknown.

"The species appears to have been somewhat abundant, judging from 

the condition in which they are grouped on the sandstone, and, although 

the specimens are obscure and too 'imperfect for positive determination 

and description, it has been-thought best to designate them, by names, 

as they will undoubtedly prove a characteristic form over a certain re-
32 THE MESOZOIC ECHINODERMATA OF UNITED STATES. [BULL. 97.

gion and of a limited horizon. The sandstone is marked by the layers 

in which they are found by ripple or wave marks, having a width of 

about 3 inches, and indicates a near proximity to a shore line over the 

area where they were obtained, and that the individuals are probably 

stranded specimens. A single very imperfect impression of a laniellibranchiate shell is present on the same fragments of rock, but too 

imperfect for determination."

Related forms. This very doubtful species scarcely admits of comparison with other forms. There is nothing hitherto reported from 

American strata that can be closely associated with it.

Locality and geological horizon. This form is reported by Whitfield 

as occurring "in red sandstones of Jurassic age, 70 feet above the red 

beds, on the east side of Spearflsh creek, near its junction with the 

Eedwater, Black Hills, Dakota."

Collection. U. S. National Museum.

GONIASTER Agassiz.

GONIASTER MAMMILLATA Gabb.

Plate v, Figs. la-h.

Goniaster mammillata Gabb, 1876. Philadelphia Acad. Nat. Sci. Proc., vol. 28, pp. 

178,179, Figs. 2, 2a, 2&.

Determinative characters. Body pentagonal, provided with a dorsal 

and a ventral row of marginal plates that are narrower than high, and 

distinctly tumid on their outer surfaces. Only detached marginal 

plates preserved.

Description. Gabb mentions the discovery of about thirty detached 

marginal plates of this species. They differ widely in shape by reason 

of their position upon the margin, but among those examined the majority are higher than wide, and swollen on the outer surfaces. Certain 

of the plates show marked protuberances upon the general level of the 

plate (PI. v, Figs, la, 16). The surface of the plates is punctate, the 

small depressions being arranged in rows that cross one another at 

right angles (PI. V, Fig. Ih).

Related forms. There are no American forms similar to this species 

with which it may be confounded, while the absence of all knowledge 

of the characters outside of a few marginal plates renders wide comparisons impossible.

Locality and geological horizon. Yellow limestone of the middle 

marl bed of the Cretaceous from Yincentown, New Jersey.

Collections. Philadelphia Academy of Natural Sciences; Johns Hopkins University.
CIDAKIS SPLENDENS. 33

ECHINOIDEA. 

tiUECIIINOIDEA.

KEGULAKES,

Test spheroidal. Ambulacra! areas narrow, more or less flexuous, 

and covered only with very small tubercles. Interambulacral areas 

very wide, with two rows of large tubercles that bear the primary 

spines. The apical disk is composed of five genital and five ocular 

plates.

CLDARIS Klein emend. Lamarck.

ClDAEIS SPLENDENS MortOll.

Plate vi, Figs. 3a-y.

Cidaris ( ?) sp. Morion, 1829. Philadelphia Acad. Nat. Sci. Jour., 1st ser., vol. 6, p. 123. 

Echinus 82). Morton, 1830.. Amer. Jour. Sci., 1st ser., vol. 17, p. 287; vol. 18, PI. in,

Figs. 12, 13.

Cidarites splendens 1 Morton, 1841. Philadelphia Acad. Nat. Sci. Proc., vol. 1, p. 132. 

Cidarites armiger Mortou, 1842. Philadelphia Acad. Nat. Sci. Jour., 1st ser., Arol. 8,

p. 215, PL n, Fig. 1.

Cidaris armiger Gabb, 1859. Cat. luvert. Fossils, Cretaceous Formation, p. 18. 

Cidaris splendeus Gabb, 1859. Cat. Invert. Fossils, Cretaceous Formation, p. 18. 

Cidaris armiger Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 75.

Determinative characters. Test of moderate size, spheroidal. Ainbulacral areas narrow, flexuous, with four rows of granules between the 

pore pairs, the outer rows larger than the inner; imperfectly defined 

granules also appear between the pores of each pair. Interambulacral 

areas very wide, with seven or eight plates in each column, each plate 

bearing a tubercle of large size, that is characterized by a wide circular 

areola, smooth boss, and small perforated inarnelon. Miliary area 

small and covered with numerous thickly- set granules of small size. 

Sutures sharply defined, depressed. Spines elongated, cylindrical, 

with longitudinal rows of sharp denticulated processes.

Dimensions. Height, % inch; width, If inches.

Description. The first mention of this form is made by Morton in 

1829, when he doubtfully referred a few fragments to Cidaris without 

an attempt at specific determination. Several of the more important 

characters were then given, but as the material examined included only 

detached plates and a few spines the description necessarily lacked 

much of completeness. In 1841 Morton proposed the name Cidarites 

splcndens and then more accurately defined the species. In 1842 lie 

redescribed and now for the first time figured the same form as Cidar-

'Murtun doubtless intended to use tlio turm splendent inxtuiul of splendent!, which is probnbly a typographical error. In t ho publication of 18i'J, vfhonTarmiijer Ls substituted, tho form splcndcns is useil.

Bull. 97 3
34 MESOZOIC ECHtNODEBMATA OF THE UNITED STATES. [BULL. 97.

ites armiger, a name which he stated he desired substituted for C. 

splendens. G-abb, in. his Catalogue of the Invertebrate Fossils of the 

Cretaceous Formation of the United States, employs both names, mistaking them for independent species, although C. splendens is referred 

to as C. splendeus. .The specimens examined by the writer are chiefly 

detached plates, and in no instance is the entire test preserved, as in 

the figure given by Morton. Two entire, or nearly entire, interarnbulacral areas, with part or all of the adjoining ambulacra, are among this 

material (PI. vi. Fig. 3a). In these specimens the oral side is slightly 

more depressed than the aboral, although not to the extent exhibited 

in Morton's figure. The ambulacral areas, which are narrow and fiexuous, have, between the poriferous avenues, four granules. In the 

center of each column of plates these granules are approximately of 

equal size, the outer rows slightly larger, but toward the disk or toward 

the mouth opening the inner rows rapidly diminish in size and finally 

disappear. The pores are oval in shape, with funnel-like openings exteriorly. Bach row of pores is separated from that which accompanies 

it in the same avenue by a row of imperfectly defined granules that 

form an undulating ridge (PI. vi, Fig. 3c).

The interambulacral areas are very wide and bear large tubercles, 

each of which covers the greater portion of its respective plate (PI. vi, 

Fig. 36). Upon the larger plates, in the center of each column, the areolas are circular, but become somewhat oval toward both disk and mouth 

opening. The outer edge of each areola is surrounded by a circle of 

large granules that give it a crenulated appearance. The areola rises 

from its "depressed margin, gradually at first, then rapidly, to the boss, 

which reaches a marked elevation above the general level of the plate. 

The boss is of moderate width and smooth. From its center rises the 

mamelon, which is small, perforated, and slightly flattened upon the 

upper surface (PI. vi, Fig. 3d). The miliary space is covered by small 

granules, that are most numerously developed along the median line of 

the interambulacra.

None of the specimens afford the apical disk. Strong auriculae show 

the presence of powerful jaws.

The spines are slender, elongated, cylindrical, with longitudinal, serrated ribs that gradually become obsolete toward the base (PI. vi, 

Fig. 3e). The collar is short and finely striated longitudinally (PI. vi, 

Fig. 3/). The acetabulum is bordered by a smooth margin and is perforated in the center (PI. vi, Fig. 3#).

Related forms. In many particulars Gidaris splendens (Morton) shows 

points of comparison with C. serrata Desor of the European Cretaceous, 

but the American species differs from it in its smaller miliary areas and 

higher areolas, and also in the presence of only four rows of granules 

between the poriferous avenues.

Locality and geological horizon. This species is reported by Morton 

from Timber creek, New Jersey, which establishes the horizon as that
CLAKK.] CIDARIS TAYLOKENSIS. 35

of the yellow limestone of the middle marl bed (upper Cretaceous). 

It has also been found by the writer near Viucentown in the same 

formation.

Collections. Philadelphia Academy of Natural Sciences; Johns Hopkins University.

CIDARIS TAYLORENSIS Clark. 

Plate VI, Figs. 2a-b.

Determinative characters. Test small. Interambulacral areas wide. 

Tubercles large, Avith circular areolas, much depressed marginally; 

boss crenulated; inarnelon perforated. Miliary space narrow. Spines 

long, cylindrical, covered with small granules arranged in longitudinal 

rows.

Dimensions. Test undetermined. Spines: length 1£ inches ( 1} ; width 

in broadest portion, -£s inch.

Description. The fragments of this form, although they admit of 

determination of but few of the important characters, warrant specific 

description from the fact that they are totally distinct from the only 

other representative of Cidaris from the Jurassic rocks of America. 

The small fragments of the interambulacral area and the spine occur 

together and doubtless formed part of the same individual. The interambulacral phites, of which only portions are preserved on the specimen 

figured, indicate a form, of no great size (PI. vi, Fig. 2a). The tubercles 

are large, with depressed areolas surrounded by a circle of large granules. The boss is crenulated and the mamelon perforated. The miliary 

space is apparently narrow, the tubercles of adjacent plates in the same 

column being nearly confluent.

The spine is Ion g, ; gently tapering toward the base in the portion 

preserved, atid' covered with longitudinal rows of small granules (PI. 

vi, Fig. 2&).

.Related forms. As the Jurassic strata of North America afford few 

fossil Echinodermata as compared with the Cretaceous, there are not 

many American types with which the present form may be compared. 

Cidaris californicus, the only other representative of this genus thus 

far reported, has no portion of the test preserved, so that the comparison 

is limited to the spines. In C. taylorensis the spines are long and 

cylindrical, while in. C. californicus they are short and thick set, and 

there is a totally different surface decoration.

Locality and geological horizon. This species is known only from the 

Jurassic strata of Taylorsville, California.

Collection. U. S. National Museum.
36 MESOZOIC ECHINOPERMATA OF THE UNITED STATES. [BULL. 97. 

ClDARIS CALIFORNICUS Clark.

Plate vi, Figs. la-b.

Determinative characters. Test unknown. Spines large, club-shaped, 

with rows of large granules that coalesce to form longitudinal ridges 

which extend from neck to point of spine.

Dimensions. Spine: length, ^ inch; breadth in thickest part, -^ inch.

Description. This species is based upon detached spines, four or 

five specimens of which are afforded in material from Taylorsville, 

California. They are distinctive in every way, and can not be mistaken, even in fragments. The specimens examined occur as casts, but 

so well preserved that impressions in gutta-percha, from which the 

drawings were made, show the characters completely. Each spine has 

a short narrow neck, beyond which it rapidly increases in size so as to 

give a club-shaped outline to the middle and upper portions. Eows of 

longitudinal granules cover the surface from the neck to the point of 

the spine, presenting the appearance of long serrated ridges (PI. vi, 

Figs. la-b).

Related forms. Separated from G. taylorensis by its club-shaped 

form and surface characters.

Locality and 'geological horizon. This species is found in Jurassic 

strata at Taylorsville, California.

Collection. U. S. National Museum.

CIDARIS TEXANUS Clark.

Plate vn, Figs. la-e. 

Cidaris texanus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 75.

Determinative characters. Test large, inflated. Ambulacral areas 

narrow, sinuous, with four ro^vs of granules between the poriferous 

avenues, which at the ambitus are increased to six and toward the apical 

disk and mouth opening are reduced to two rows. Pores oval, separated by transverse elevations, which partially envelop the openings. 

Interainbulacral areas wide, with large circular tubercles. Areola circular, depressed; boss smooth; mamelon small, perforated. Miliary 

space wide, covered with numerous small granules. 

. Dimensions. Height, 1£ inches; width, 2^ inches.

Description. A large portion of the test of this beautiful species is 

in an excellent state of preservation. All of the characteristic features, 

with the exception of those relating to the apical disk and mouth edges, 

are clearly shown. The test, however, is somewhat compressed, so 

that the original form can not be with certainty made out. The ambulacra! areas are narrow and slightly flexuous. Between the poriferous avenues, which are narrow and depressed, are four rows of granules 

of nearly equal size which directly at the ambitus are increased to six,
CLARK.] CIDAETR WALCOTTI.. 37

while toward both apical disk and mouth opening- they are reduced to 

two. Irregularly scattered among- the rows of granules are others 

smaller in size. The pores are oval and separated by transverse elevations that partially encircle the openings, leaving a depression 

between each pair (PL vn, Fig. Ic).

The interambulacral plates are wide and bear large circular tubercles (PL vn, Fig. 1$). The areola of each tubercle is radially ridged, 

deeply depressed, and surrounded by a row of mammilated granules. 

The boss is slightly elevated above the level of the plate, and presents 

a smooth and sharp ridge around the small perforated mamelon (PL vn, 

Fig. le). The .miliary space is wide and thickly set with small elevated 

granules of equal size. The apical disk and mouth edges are lacking.

Related forms. At first sight this species shows strong points of 

similarity with C. sceptrifcra Mantell from the White Chalk of England, 

although the arrangement of granules in the ambulacral area is different. The areola of C. aceptrifera is described as smooth, while that of 

G. texanus is clearly ridged radially. The only related form reported 

from Texas is Leioddaris hemigranosus, formerly referred to Cidaris, but 

which, as will be shown, does not belong to that genus. Gidaris Branncri, from Brazil, described by White, is allied to G. texanus, although 

presenting differences in the character of the areola and arrangement 

of granules in both the ambulacral and interambulacral areas.

Locality and geological horizon. This form is found in the Washita 

formation of the Comanche series (lower Cretaceous) of Bexar county, 

Texas.

Collection. U. S. National Museum.

CIDARIS WALCOTTI Clark.

 ,

Plate vi, Figs. 4=a-d

Cidaris Walcotti Clark, 1891. Johns Hoplcius University Circulars, No. 87, p. 75.

'.Determinative characters. Test small, inflated. Ambulacral areas 

narrow, sinuous, with four rows of granules between the depressed 

poriferous avenues. Interambulacral areas broad; each tubercle with 

depressed circular areola, smooth boss and small imperforate mamelon. 

Miliary space wide, thickly covered with small granules.

.Dimensions. Height, 1 inch (?). Width, 1£ inches (*?).

Description. The fragments of this form examined are sufficiently 

distinctive to separate it from other species. A nearly complete iuterambulacral area, with the adjoining ambulacra, shows that the test of 

tlie species is small and in a marked degree inflated (PL vi, Fig. 4«).

The ambulacral areas are narrow, slightly sinuous, and provided with 

four nearly equal rows of granules between the poriferous avenues (PL 

VI, Fig-. 4c). At times additional granules are irregularly interspersed. 

The poriferous avenues themselves are narrow, deeply depressed, and 

slightly sinuous. The pores are round, with funnel-shaped openings,
38 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

produced by the intersecting ridges. These ridges, which separate the 

individual pores and the pore pairs, give a lattice-like appearance to 

the poriferous zones.

The interambulacral plates are moderately large. On account of the 

indistinctly marked sutures the small tubercles and numerous granules 

cause a very even surface over the entire interambulacral area (PI. vi, 

Fig. 4ft). The tubercles are circular and stand nearer the outer margin 

of the plates than the inner. The areolas are deeply depressed, the 

central portion but slightly exceeding the margin in height. The boss 

is smooth and-stands but little above the level of the plate. The mamelon is imperforate (PL vi, Fig. 4«5). The wide miliary space is covered 

with a large number of irregularly arranged granules of equal size. 

The broken specimens afford no information as to the character of the 

apical disk or mouth edges.

Related forms. This species is very readily separated from G. splendens, the only other representative of this genus thus far reported from 

the Atlantic Coast Cretaceous, in possessing imperforate inamelons 

and wide miliary spaces, over which the granules are regularly scattered. The even surface of the test is likewise a distinguishing feature.

Locality and geological horizon. The specimens of this form examined 

by the writer were found associated with C. splendens in the yellow 

limestone of the middle marl bed (upper Cretaceous), of Timber creek, 

New Jersey.

Collection. Philadelphia Academy of Natural Sciences.

LEIOCIDARIS Desor.

LEIOCIDARIS HEMIGRANOSUS (Shumard).

Plate vu, Figs. 2o-d. Plate vm, Figs. la-b. Plate ix, Fig. lci-c.

Cidaris liemigranosus Shumard, 1860. Sfc. Louis, Acad. Sci. Traus., vol. 1, p. 609.

Cidaris hemigranosus Meek, 1864. Smith. Misc. Coll. (vol. 1, 177), p. 2.

Cidaris hemigranosus White, 1883. U. S. Geol. and Geog. Surv. of the Territories, 12th

Ann. Kept, for 1878, p. 38, PI. 18, Figs. 2a-l. 

Leiocidaris hemigranosus Clark, 1891. Johns Hopkins University Circulars, No. 87,

p. 75.

Determinative characters. Test very large, subspherical. Ambulacra! areas narrow, sinuous, with six rows of granules in the middle. 

Poriferous avenues wide, deeply depressed. Pores of each pair united 

by clearly denned furrow. Interambulacral areas broad. Tubercles 

very large5 areola circular or slightly polygonal, depressed; boss 

smooth; mamelon large, perforated. Miliary space covered with large 

scattered oval granules. Sutures clearly marked, depressed.

Dimensions. Height, 2£ inches; width, 3f inches.

Description. This form, which was quite fully described by Shumard 

in 1860, but not figured, was incorrectly referred to the genus Cidaris,
cr-AKK.] LEIOCIDARTS HEMIGRAHOSUS. 39

from which it is separated by the presence of furrows uniting the pores 

of each pair. In this respect it is a typical representative of the genus 

Leiocidaris of Desor. A very good illustration is given by Dr. White 

in the Twelfth Annual Eeport for 1878 of the U. S. Geological and Geographical Survey of the Territories, although necessarily, from the size 

of the figure, the furrows connecting the pores are not very distinctly 

shown. This species is the largest echinoid known from the Texas 

Cretaceous, and, with possibly a single exception, the hfrgest from the 

American Mesozoic. In one unusually fine specimen obtained from 

Prof. E. T. Hill the test is subspherical, although considerably broader 

and more flattened on the oral than aboral side. 1

The ambulacral areas are narrow and sinuous, with six rows of granules between the poriferous avenues (PI. vn, Fig. 2 lj).- The regular 

arrangement of the granules is not persistent, the number being increased irregularly near the middle of the column and somewhat reduced 

towa,rd the apical disk and the mouth opening. The poriferous avenues 

are wide and deeply depressed, the pores of each pair being united 

by a shallow furrow.

The interambulacral areas are wide and the plates of massive size 

(PI. vn, Fig. 2a). The /tubercles occupy the center of the plates and 

are large and prominent. The areolas are deeply depressed, subcirculai- or slightly polygonal, and occupy more than half of the greatest diameter of the plates. On all the specimens examined the areolas show 

perfectly smooth surfaces, although Shumard mentions the occurrence of 

radiating ridges. Toward the center each areola rises to form the boss, 

which is provided marginally with a sharp smooth ridge. The mamelon is large, subspherical, with a deep perforation upon its summit (PI. 

vn, Fig. 2c). The niiliary space is wide and covered with large, irregularly-shaped and flattened granules, some round and some oval in form. 

Interspersed among these are much smaller grannies, which increase in 

number along the margin of the plates. The apical disk and mouth 

edges are wanting.

Related forms. This species is readily separated from any hitherto 

described from American or European strata. Its characters are well 

defined and distinctive.

Locality and geological horizon. Shumard says that it is found "in the 

Washita limestone [Coiuanche series (lower Cretaceous)], forming the 

upper part of the Bluff of Eed river, Lamar county, and 10 miles above 

the mouth of Kiamesha creek, at both localities associated with Ostrea 

quadriplicata." This places it in the Denison beds. It has only been 

reported from Texas.

Collections. U. S. National Museum; Prof. E. T. Hill.

1 A much more perfect specimen (PI. ix, Figs, lo-c) lias been examined by the writer since the above 

description was prepared.
40 MESOZOIC EGHINODERMATA OF THE UNITED STATES. [BULL. 97.

SALENIDJE.

Test spheroidal or depressed. Ainbulacral areas narrow, straight 

or flexuous; poriferous zones narrow; pores round, uuigeniinal, often 

increased in number toward the mouth-opening. Interambulacral areas 

broad, with two rows of primary tubercles. Apical disk large and 

prominent. Mouth opening large, with incisions at regular intervals. 

Anal opening eccentric.

SALEMA Gray.

SALENIA TEXANA Credner.

Plate x, Figs; la-h.

Cidaris diatretum Giebel, 1853, Jahresber. d. Naturw. Vereins in Halle, 1852, p. 374,

PI. 7, Fig. 2. 

Salenia texana Credner, 1875. Zeitschr. f. d. Ges. Naturw., XLVI, pp. 105-116, PI. v,

Figs. 1-6. 

Salenia texana Clark, 1891. Jolfns Hopkins University Circulars, No. 87, p. 75.

Determinative characters. Test subglobo'se; upper surface convex; 

sides inflated; under surface flat. Ambulacra narrow, flexuous, with 

two rows of mammillatecl granules in each area: poriferous zones flexed; 

pores unigeininal. Interambulacral areas wide, with two rows of alternating plates, six in each row. Apical disk large, convex, subcircular; 

anal opening prominent. Mouth opening moderately large.

Dimensions. Height, f inch; transverse diameter, 1 inch.

Description. Credner in the Zeitschrift fiir die gesaminten Naturwissenschaften zu Berlin for 1876 presents the first complete diagnosis 

of a North American Mesozoic echinoid, in the detailed descriptions 

accorded the present species. Its reference by Professor Giebel in 

1852 to Cidaris diatretum (=Pseudodiadema diatretum) is shown from 

the carefully prepared specimens to have been erroneous.

The test is subspherical when complete, but in the specimens examined is generally somewhat flattened, both actinally and abactioally. 

The lower surface is slightly concave in the vicinity of the mouth opening. The sides are inflated, presenting a rounded surface which is fuller 

above than below (PI. x, Fig. Ic).

The ambulacral areas are narrow, increasing gradually in width from 

the apical disk to the mouth opening. Two rows of mamniillated granules, twenty-four to twenty-six in each, occupy the middle of each area. 

Yery minute granules extend in a line between the rows and in the 

vicinity of the mouth opening surround the larger granules themselves. 

The poriferous zones are narrow and flexuous and the pores are regularly arranged in a unigeminal series; near the mouth opening they 

are slightly more crowded. The most pronounced flexure is opposite 

the second interambulacral plate from the apical disk. Toward the 

mouth opening the zones become nearly straight (PI. x, Figs, le, If).
CLAIIK.] SALENIA TUMTD1TLA. ' 41

The interainbulacral areas are broad, and formed of two alternatingrows of broad plates, six in each row (PI. x, Fig. 1$). The tubercles 

increase rapidly in size from the mouth edges, where they are scarcely 

larger than the mamillated granules of the ambulacral areas. The 

areolas are large, and surrounded by mamillated granules of various 

sizes, that are crowded together along the inner edge of the plates. 

Between the larger granules are numerous minute granules. The areola rises to a prominent boss, that is deeply crenulated, and bears an 

imperforate mamelon (PI. x, Fig. Hi).

The apical disk is very large, convex, subcircular, with radiating 

ridges that extend from the ovarial openings of each plate and unite 

with similar ridges of adjacent plates. Small punctures arc found at 

the angles of the plates and intermediate between them (PL x, Fig. 10). 

The subanal plate is situated before the anal opening, and occupies the 

center of the disk. The anal opening is subelliptical, rounded anteriorly, angular posteriorly, and slightly elevated at the border.

The under surface is flat and the mouth opening large, covering 

nearly one-half the diameter of the test. The mouth opening is circular, with ten incisions upon the edge that divide it into nearly equalsized lobes (PL x, Fig. II).

Related forms. Credner, in discussing the affinities of this form, considers it to be closely related to Salenia petalifera Defr., and S. J)esori 

Wriglit. It is somewhat more elevated than S. petalifera, and the 

radial ridges on the apical disk are less pronounced on the latter.than 

on the former. The ocular plates also enter less compactly into the 

composition of the disk in the latter species. In S. Desori, on the other 

hand, there is a wider difference, both in the character of the test 

plates and the decorations of the.apical disk. With 8. scutigera Gray 

it also shows some points in common.

Locality and geological horizon. This form is from Cileola, Comanche spring, Texas, in the Washita formation of the Comauche 

series (lower Cretaceous).

Collections. U. S. National Museum; Boston Society of Natural 

History.

SALENIA TUMIDULA Clark.

Plate xi, Figs. la-j. 

Salenia tumidula Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 75.

Determinative characters. Test small, subglobose; outline of upper 

surface regularly convex. Ambulacral areas narrow, nearly straight, 

with two rows of mammillated grannies between the pore pairs; poriferous zones slightly flexed; pores unigeminal. Interambulacral areas 

wide', composed of two alternating rows of five or six plates. Apical 

disk large, regularly convex, subcircular; anal opening slightly elevated. Mouth opening small.

-Dimensions. Height, f inch; transverse diameter, £ inch.
42 MESOZOIC ECHItfODEEMATA OF THE UNITED STATES. [BULL. 97.

Description. The perfectly preserved specimens of this beautiful 

species admit of a determination of all the details of structure.

The general form of the test is subglobose. The sides are inflated 

and regularly curved, rising into a convex upper surface, from which 

the anal opening projects but slightly (PI. XT, Fig. Ic). ^The lower surface is quite flat, and toward the mouth opening slightly depressed.

The ambulacral areas are rather broad, increasing in width from the 

apical disk to the mouth edges (PL xi, Fig. I/). Extending along the 

center of each area are two rows of mammillated granules, fifteen or 

sixteen in each row, between which are other minute granules. The 

poriferous zones are narrow and nearly straight; the pores round, 

regularly arranged in a unigerninal series, and largest in the middle of 

the column. *

The interambulacral areas consist of two rows of alternating plates, 

five or six in each TOW (PI. XI, Fig. Id). The larger tubercles diminish 

rapidly in size toward the mouth edges, and are very indistinct on the 

plates bordering the same. Each areola is large and circular, the boss 

crenulated, and the rnamelon flattened and imperforate (PL xi, Fig. Ij). 

The miliary space is bordered with oval granules of irregular size and 

arrangement, although most numerous between the rows of tubercles. 

The sutures of the plates are very indistinctly marked.

The apioal disk is prominent, subcircular, with a regularly curved convex surface, from which the anal aperture projects but slightly. The 

granular decorations of the surface often coalesce and appear as broken 

ridges extending radially from the five openings in the genital plates 

(PL xi, Fig. Ig). The anal opening is oval ? slightly pointed below, and 

projects but slightly above the level of the apical disk. It is bordered 

by a flange-like edge that is formed of the anal and two genital plates.

The mouth opening is small, occupying scarcely two-fifths of the diameter of the test. Ten incisions divide the edge into lobes, the ambulacral lobes projecting the farther (PL xi, Fig. 1?').

Related forms. The identity of this species is readily established by 

tbe straight poriferous zones and peculiar decorations of the apical 

disk. The number of mammillated granules in the ambulacral areas is 

less than in 8. texana, while the oval granules of the interambulacrai 

areas are readily distinguishable from the round forms of-8. bellula.

The anal aperture also projects far less than in 8. texana, although 

in this respect it is not unlike 8. bellula.

Locality and geological horizon. This species is from the yellow limestone of the middle marl bed (upper Cretaceous) of Timber creek, New 

Jersey.

Collection. Philadelphia Academy of Natural Sciences; Johns Hopkins University.
CLAHK.] SALENIA BELLULA. 43

SALENIA BELLULA dark. 

Plate xi, Figs. 2a-g.

Salenia lellula Clark, 1891. Johns Hopldus University Circulars, No. 87, p. 75.

Determinative characters. Test small, compressed, circular; upper 

surface convex; sides inflated; under surface flat. Ambulacral areas 

rather broad, nearly straight, with two rows of granules in each row; 

poriferous zones broad, very slightly flexed; pores round, unigeininal. Interambulacral areas wide. Apical disk convex and nearly 

circular. Mouth opening small.

Dimensions. Height, £ inch; transverse diameter, -f$ inch.

Description. This Salenia is a very rare form; only a few specimens 

having come under the notice of the writer, yet from certain peculiarities of outline and structure it is not to be confounded with other species 

heretofore described.0

In general 'outline the test is somewhat flattened; the upper surface 

is regularly convex, the sides are inflated, the lower surface is flat or 

slightly concave at the mouth opening.

 The ambulacra! areas are prominent and change but slightly in width 

from the apical disk to the mouth edges. Two rows of mammillated 

granules, fifteen in each, occupy the center of each area.

The interambulacral areas are wide and consist of two rows of alternating plates, five or six in each. The tubercles are prominent, but 

decrease rapidly in size toward the mouth edges. The areola is of moderate size, the boss narrow and indistinctly crenulated, and the mamelon small, flattened, and imperforate (PI. xi, Fig. 2g). An indistinct 

circle of mammillated granules surrounds each tubercle. They unite to 

form a, sinuous double series between the rows of tubercles. Between 

the larger granules are scattered irregularly numerous small granules 

that are crowded together along the central line of the interambulacral 

area (PI. xi, Fig. 2cl}.

The apical disk is slightly convex, the anal opening interfering but 

little with the regularity of the curved surface. The anal opening is 

subcircular, with a flange-like rim. The plates are decorated with 

oval granules that are arranged in radial rows extending from the 

opening of each genital plate and, unite with corresponding rows'of adjacent plates at the suture (PI. xi, Fig. 2/).

The mouth opening is small, being but one-third of the transverse 

diameter of the test. Ten weak incisions divide the edges into lobes 

that are nearly of equal size (PI. xi, Fig. 21).

Related forms. This species is quite distinct from Salenia texana or 

$. tumidula, and a,t the same time does not admit of reference to any of 

the European species. It is most closely related to 8. tumidula, but is 

more compressed, has a differently shaped and decorated apical disk', 

and has round and mammillated granules in the miliary space, while 

those of S. tumidula are characteristically oval.
44 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

Locality and geological horizon. This species, like S. tttmidula, is 

only found in the yellow limestone of the middle marl bed (upper Cretaceous) of Timber creek, New Jersey.

Collections. Philadelphia Academy of Natural Sciences; American 

Museum of Natural History, New York.

DIADEMATID^.

Test more or less spheroidal. Ambulacral areas broad, at times approaching the iuterambulacral in width. The ambulacra! plates are 

generally compound; the pores unigeminal, increasing oftentimes in 

the vicinity of the peristoine. The mouth opening is large, with deep 

incisions, and provided near the margins with well-developed auriculae. 

The spines are frequently large and variable in shape.

HEMICIDARIS Agassiz. " 

HEMIOIDARIS INTUMESCENS Clark. 

Plate xii, Figs. la-i.

Determinative characters. Test spheroidal, upper surface inflated, 

lower surface flat. Ambulacral areas moderately broad, increasing in 

width from the apical disk to the mouth edges. The tubercles at the 

peristoine are nearly equal in size to those of the iuterambulacral areas, 

but become greatly reduced in passing from the ambitus to the a.pical 

disk. Interambulacral areas rather wide, with two rows of large tubercles. Miliary space wide, covered with numerous granules. Mouth 

opening moderately wide, with deep incisions.

'Dimensions. Height, £ inch; transverse diameter, f inch.

Description. The very perfectly preserved molds of this species permit 

the taking in gutta-percha of all the details of form and structure. As 

the only representative of this genus in American deposits it possesses 

considerable interest. The test is of moderate size, with a convex and 

slightly inflated upper surface and nearly flat lower surface. The 

slightly flexuous ambulacral areas broaden- from the region of the apical disk toward the ambitus and slightly contract again before the 

peristome is reached. The tubercles are prominent in the lower part 

of the column, where several pairs attain a size nearly equal to those 

of the interambulacral areas. Minute perforated granules succeed them 

above and continue as a double row to the apical disk. The poriferous 

zones are slightly flexuous, and the small pores are uuigeminally arranged, although somewhat increased in the vicinity of the mouth 

edges.

The interambulacral areas are from three to four times the width of 

the ambulacral at the ambitus. The two rows of medium sized tubercles occupy the center of the plates; the areola is circular and slightly 

elevated; the boss deeply crenulated, and the mamelon distinctly per-
OLA .] PSEUDODIADEMA EMERSONI. 45

forated. There are about eight primary tubercles in each row. The 

apical disk is rather large, although not sufficiently well preserved to 

admit of a determination of the individual plates.

The mouth opening is small and occupies scarcely one-half of the diameter of the test. It is deeply notched, the lobes being nearly equal 

in size.

Related forms. The present species of Heinicidaris is the only representative of the genus known from American deposits. A comparison 

with European species fails to identify it with any described forms.

Locality and geological horizon. This species is from the Jurassic 

strata of Taylorsville, California.

Collection. U. S. National Museum.

PSEUDODIADEMA Desor.

PSEUDODIADEMA EMERSONI Clark.

Plate xii, Figs 2a-e.

Determinative characters. Test circular, depressed. Ambulacral 

areas straight and prominent; poriferous zones narrow; pores uni geniinal. Interambitlacral areas not quite twice the width of the ambulacral, with two rows of large tubercles, eight or nine in each row. 

Mouth opening wide.

Dimensions. Height, % inch; transverse diameter, f inch (!).

Description. The beautifully preserved molds of this interesting 

form were collected by Prof. Hyatt from the Jurassic beds of Taylorsville, California. The gtitta percha casts from which the drawings 

were made represent very perfectly all the details of structure. The 

test is nearly circular, the prominent ambulacral areas giving it a 

slightly subpentagoual outline. The ambulacral areas are rather more 

than one-half the width of the interambulacral, and support two rows 

of primary tubercles somewhat smaller than the interambulacral 

tubercles. There are nine or ten iu each row. Between the tubercles 

are numerous granules that are arranged in an undulating line between 

the rows and along the margin. They nearly disappear between the 

tubercles of the same series. Toward the apical disk the tubercles are 

greatly reduced in size. The pores are uuigeminal, there being three 

or four opposite each ambulacral plate.

Theinterainbulacral areas bear two rows of primary tubercles, eight or 

nine in each, that are only slightly larger than those of the ambulacral 

areas. They increase from the peristome to the ambitus, after which 

they rapidly decrease in size. The areolas are nearly confluent above 

and below, broader than long, and rise into prominent bosses that are 

not deeply crenulated. The mamelou is distinctly perforated. The 

miliary space is covered with granules of different sizes. There are no 

secondary tubercles developed near the mouth opening. The lower sur-
46 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

face is flat, the mouth opening large and deeply notched; the ambulacra! lobes larger than the interambulacral. The apical disk is not 

preserved.

Related forms. As the only Pseudodiadema in the Jurassic of America 

it is unique, while its identity with any European form is very doubtful.

It closely resembles P. Baileyi, from England, in many particulars, 

but it is a less depressed form, with more rounded sides and more 

numerous granules in the miliary space.

Locality and geological horizon. This species is found in the Jurassic 

beds of Taylorsville, California, and is named in honor of Prof. B. K. 

Emerson, of Amherst College, from whom the writer received his first 

instructions in geology and paleontology.

Collection. U. S. National Museum.

PSEUDODIADEMA DIATRETUM (Morton). 

Plate xiu, Figs. la-f.

Cidaris diatretum Morton, 1833. Am. Jour. Sci., 1st ser., vol. 23, p. 294.

Cidarites diatretum,Morton, 1834. Synop. Organ. Remains, Cretaceous, p. 75, PI. 10,

Fig. 10.

Cidaris diatretum Bronn, 1848, Index Pal., vol. 1, p. 298. ^ 

Pseudodiadema diatretum Desor, 1858. Synopsis des fichinides fossiles, p. 73. 

Cidaris diatretum Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 18. 

Pseudodiadema diatretum Cotteau, 1862-'67. Paldont. francaise, vol. 7, p. 519. 

 Pseudodiadema diatretum Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 2. 

Pseudodiadema diatretum Conrad, 1868. Geol. of N. ,!., Appendix, p. 722. 

Cidaris clavigera Credner, 1870. Zeitschr. d. deutsch. geol. Gesells., vol. 22, p. 218, 

Cidaris scejptrifera Credner, 1870. Zeitschr. d. dentsch. geol. Gesells., vol. 22, p. 218. 

Pseudodiadema diatretum Clark, 1891. Johns Hopkins University Circulars, No. 87,

p. 75.

Determinative characters. Test circular, convex above, concave below, sides inflated. Ambulacra wide, sinuous, with two rows of tubercles, that are large at the ambitus and decrease toward the poles; 

poriferous zones narrow, sinuous. Inter ambulacra with two rows of 

primary tubercles and several irregular rows of secondary tubercles. 

Month opening narrow, about one-third the diameter of the test.

Dimensions. Height, £ inch; transverse diameter, 1^ inches.

Description. The specimens of this species vary greatly in size, the 

full-grown forms being moderately large. The test is circular, depressed, 

slightly convex above, concave below. The sides are inflated (PI. xm, 

Fig. 16).

The ambulacral areas are wide, slightly raised, and furnished with 

two rows of tubercles, thirteen to fourteen in each row. They are 

large and prominent at the ambitus, but decrease gradually toward 

the poles. The broad areolas, that are sharply depressed in their marginal portions, are striated by faint radial ridges on the outer sides. 

At the upper and inner angle of each plate is a small secondary tubercle, while irregularly scattered over the othoi- portions of the plates are
CLARK.] PSEUDODIADEMA TEXANUM. _ 47

smaller tubercles, and between them minute granules. The poriferous 

zones are slightly flexed, the pores of each, plate being disposed in 

curved form about the margin (PI. xnj, Fig. Id). Although there are 

generally three pairs of pores on each plate, four pairs are not infrequent near the ambitus (PI. xm, Fig. le).

The iuterainbulacral areas are about one and one-half times the width 

of the ambulacra!, and have two rows of tubercles .somewhat larger than 

those of the latter. There are, in addition, several irregular rows of. 

secondary-tubercles, of various sizes, that are most numerous between 

the rows of primary tubercles and the poriferous zones. Sparsely 

scattered over the interainbulacral space are flattened granules (PI. 

xm, Fig. le).

The primary tubercles of both the ambulacra! and interainbulacral 

areas have wide circular areolas, elevated and deeply crenulated bosses, 

and distinctly perforated mainelons (PL xm, Fig. If).

The mouth opening is narrow, reaching scarcely one-third the diameter of the test. The incisions of the margin are weak (PI. xm, Fig. la).

The discal opening is subpentagonal.

.Related forms. This species resembles in some particulars Pseudodiadema ornattim Goldftiss, of the Cretaceous of Europe, but the latter 

form has a different arrangement of the secondary tubercles and granules and lacks the radial striation upon the areolas.

Locality and geological horizon. Pseudodiadema diatretum is from 

the yellow limestone of the middle marl bed (upper Cretacous) of Timber creek, New Jersey.

Collections. Philadelphia Academy of Natural Sciences 5 American 

Museum of Natural History, New York.

PSEUDODIADEMA TEXANUM (Koemer). 

Plate xm, Figs 2a-b. Plate xiv, Figs. la-g.

Diadema texanum Roeiner, 1852. Die Kreidebildungeri von Texas, p. 82, PI. 10, Fig. 5. 

Pseudodiadema texanum Deaor, 1858. Synop. des Echinides foseiles, p. 72. 

Diadema texanum Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Pseudodiadema texanum Meek, 1864. Smith Misc. Coll. vol. 7 (177), p. 2. 

Pseudodiadema Eoemeri Clark, 1891. Johns Hopkics University Circulars, No. 87, p. 75.

Determinative characters. Test small, circular, depressed; sides inflated; upper and lower surfaces about equally flattened. Ambulacra 

narrow, with two rows of primary tubercles, eleven or twelve in each row; 

poriferous zones narrow, pores unigeminal. Interambulacra wide, with 

two rows of primary tubercles of larger size than those of the ambulacra. Mouth opening wide, covering nearly one-half the diameter of the 

test. Discal opening subcircular, with deep incision in right anterior 

ambulacrum.

Dimensions. Transverse diameter, f inch; height, -fa inch.

Description. This form, described by .Roeiner, in 1852, as Diadema 

texanum, was assigned a new name (P. Eoemeri) by the writer in his
48 MESOZOIC ECHINODEBMATA OF THE UNITED STATES. [BULL. 97.

preliminary report, 1 when Cypkosoma texanum of the same author was 

referred to Pseudodiadema. The reference of the latter form to Diplopodia, in the present report, makes it possible to return to the earlier 

name for the present species.

The test is circular, very much depressed on both the upper and 

lower surfaces and inflated at the sides (PI. xiv, Fig. Ic).

The ambulacral areas are narrow and lanceolate. They bear two 

rows of tubercles, eleven or twelve in each ro vr, that decrease rapidly 

in size from the ambitus to the poles (PI. xiv, Fig. le; PL xiii, Fig. 2b). 

The areolas are circular, the bosses stout and prominent, the mamelons 

distinctly perforated (PL xiv, Fig. .!</). Small secondary tubercles are 

irregularly dispersed between the rows of primary tubercles. A few 

scattered granules surround the same. The poriferous zones are unigeminal throughout, though the pores show a slight tendency to increase at the peristome.

The interainbulacral areas are about twice the width of the ambulacral. There are two rows of primary tubercles, nine or ten in each 

row, that decrease in size from the ambitus to the poles (PL xiv, Fig. 

Id; PL xiii, Fig. 2a). The areolas are depressed, circular, and distinctly outlined, the bosses elevated and deeply crenulated, the inamelons large and deeply perforated. Small secondary tubercles surround 

the primary tubercles, between which are interspersed minute granules 

(PL xiv. Fig. If).

Tfye mouth opening is wide, covering nearly one-half of the diameter 

of the test. Ten incisions produce well-defined lobes at regular intervals (PL xiv, Fig. 16). The discal opening is large and subcircular, with 

a deep incision in the right anterior ambulacrum (PL xiv, Fig, la).

Related forms. Both Koemer and Desor mention the similarity of 

this species to P. tenue, cf the Ceuomanian of Europe, from which, however, it is separated by its smaller tubercles and more numerous granules.

Locality and geological horizon. This important species is common in 

the Fredericksburg formation of the Coinaiiche series (lower Cretaceous) 

of Texas, and is found at Fredericksburg and near San Saba valley.

Collection. U. S. National Museum.

DIPLOPODIA McCoy.

DIPLOPODIA TEXANUM (Eoemer).

Plate xv, Figs, la-/; Plate xvi, Figs. la-d.

Diadema texanum Eoeruer, 1849. Texas, etc., p. 392.

Cyphosoma texanum Roeiner, 1852. Die Kreidebildungen von Texas, p. 82, PI. 10,

Fig. 6. 

Cypliosoma texanum Conrad, 1857. U. S. aud Mex. Bound. Surv. Kept., vol. 1, pt. 2, p.

1-15, I'l. 1, Fig. 3. - ' 

Phymoaoma tcxanmn Do.sor, 1858. Synopsis des Echinides fossiles, p. 90.

1 Johns Uopkins "University Circulars, 1891, No. ti7, pp. 75-77.
CLAEK.] DIPLOPODIA TEXANUM. 49

Cyphosoma texanum Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 18.

Cijpliosoma texanum Gabb, 1869. Calitbruia Geol. Snrv., Paleontology, vol. 2, p. 276.

rseudodiadema, texanum Clark, 1891. Johns Hopkins University Circula rs, No. 87, p. 75.

Determinative characters. Test large, subcircular; .sides inflated5 

upper surface elevated; lower surface depressed, concave. Ambulacra 

prominent, with two rows of primary tubercles; poriferous zones broad 

above, narrow below; pores in single pairs from peristome to ambitus, 

beyond which to the apical disk they are bigeininal. Interambulacra 

wide, with four rows of primary tubercles at the ambitus, which become 

reduced to two at the poles. Mouth opening wide, about two-fifths 

the diameter of the test. Discal opening large, subpentagonal.

Dimensions. Transverse diameter, If inches; height, £ inch.

Description. This species was first described by Boomer, in 1849, in 

Texas, etc., as Biadema texanum, but subsequently, in 1852, referred to 

Gypliosoma. Although the perforated mamelons are not always shown 

with distinctness at the first glance, they are sufficiently numerous 

upon careful inspection to warrant the removal of this form from the 

genus Cyphosoma.

The test is large, subcircular- and elevated (PI. xv, Fig. Ic). The 

sides are inflated, and the upper surface elevated and convex. The 

base is depressed and concave.

The ambulacra! areas are broad and lanceolate. They have two rows 

of primary tubercles, fourteen or fifteen in each, series, that are large at 

the ambitus and decrease gradually toward the poles (PI. xv, Fig. 1$). 

A circle of scattered granules surround the narrow areolas. The poriferous zones are broad upon the upper surface, but below the ambitus are 

very much narrowed. The pores are in single pairs below the ambitus, 

except directly at the mouth edges, where they become greatly increased, 

as shown in Plate xvi, Fig. la. From the ambitus to the apical disk 

they are bigeminal (PL xv, Fig. le), a character which Duncan, in his 

recent revision of the Echinoidea, considers of generic importance and 

sufficient ground for a separation of Diplopodia from Pseudodiadema.

The interanibulacral areas are about one and one-half times the width 

of the ambulacra! at the ambitus. There are four rows of primary 

tubercles at the ambitus (PL xv, Fig. If), which, become reduced to 

two in the vicinity of the apical disk and mouth edges (PL xvi, Fig. 1&, 

Ic). In the center of the column the tubercles of the four rows are of 

about equal size, but those of the outer rows become much more rapidly 

reduced in size toward the poles. Small secondary tubercles are found 

on the outer margin of the plates, while irregularly scattered granules 

cover the space between the tubercles. A broad depression occurs 

along the line of the central suture in the vicinity of the discal opening.

The mouth opening is circular, but is broken by distinct incisions. 

Its diameter is about two-fifths that of the test (PL xv, Fig. 11).

The discal opening is large and subpentagonal (PL xv, Fig. la), 

Bull. 97 4
50 MESOZOIC ECHINODEEMATA OF THE UNITED STATES. [BULL.97.

Related forms. This species is closely allied to or perhaps identical 

with the form described by D'Orbigny in 1842 from the United States of 

Colombia under the name of Echinus Bolivarii, and later recognized by 

Gabb in a collection obtained from Peru. As the original description 

and figures leave some doubt as to the determination of the species, the 

term texanum is retained here.

Locality and geological horizon. This form is found in the Fredericksburg formation of the Comauche series (lower Cretaceous) of Texas. It 

is from the Comanche Peak beds, and is reported from Fredericksburg and near the head of the San Saba river.

Collections. U. S. National Museum; Boston Society of Natural History; Texas Geological Survey; University of Iowa; Prof. Eobt. T. Hill.

DIPLOPODIA HILLI Clark. -

Plate xvi, Figs. 2a-g.

Pseudodiadema HiUi Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test subpentagonal3 depressed; sides inflated; upper and lower surfaces flattened. Ambulacra prominent, 

straight, with two rows of primary tubercles, twelve or thirteen in each 

row; poriferous zones narrow, with slight increase in width toward the 

apical disk; pores in single pairs below but bigeminal on the upper 

surface. Interambulacra with two rows of primary tubercles of equal 

size with those of the ambulacra. Mouth opening narrow, circular. 

Discal opening broad, pentagonal.

Dimensions. Transverse diameter, f inch; height, -/g- inch.

Description. This rare Diplopodia has a subpentagoual outline, the 

projecting ambulacra occupying the angles. It is depressed on both 

the upper and lower surfaces, the latter becoming somewhat concave 

toward the mouth opening. The sides are moderately inflated.

The ambulacra are broad, very prominent, and furnished with two 

rows of large tubercles, twelve or thirteen in each row, that decrease 

rapidly from, the ambitus toward the apical disk and peristome. The 

poriferous zones are narrow and lanceolate. The pores are arranged 

in single pairs on the lower surface, but from the ambitus to the apical 

disk are increased slightly in number, and near the 'apical disk become 

bigeminal (PL xvi, Fig. 2d)'. The mterambulacral areas are narrow 

and appear flattened, as compared with the slightly projecting ambulacra. They are provided with two rows of primary tubercles of equal 

size with those of the ambulacra (PL xvi, Fig. 2/). There are ten or 

eleven in each row. The areolas are narrow, circular, and elevated, the 

bosses prominent and distinctly crenulated, and the mamelons deeply 

perforated. The tubercles are somewhat widely separated and the intervening space is covered with small secondary tubercles and sparsely 

scattered granules.

The mouth opening is broad, depressed, and circular. It is divided
CLAEK.] COPTOSOMA MORTONI. 51

by ten incisions into well-defined lobes, those of the ambulacra broader 

and extending farther into the opening than the others (PI. xvi, Fig. 26).

The distal opening is pentagonal, the angles occurring at the point of 

the medial suture of the inter ambulacra (PL xvi, Fig. 2a).

Eclated forms. Diplopodia Jlitti appears at first glance closely allied 

to, if not -identical with, Pseudodiadema texanum. It is separated from 

the same, however, by its larger size, subpentagonal form, and increase 

in number of pores from the ambitus to the apical disk. In this latter 

particular it is not unlike D. texanum, from Avhich, however, it is separated by its smaller size, subpentagonal form, and two instead of four 

rows of primary tubercles. It is similar to P. Rhodani of the European 

Cretaceous in some particulars, but that form is without the increase in 

number of pores on the upper surf ace and likewise possesses more plates 

in each column.

Locality and geological horizon. This species is from the Austin chalk 

(upper Cretaceous) of Texas.

Collections. U. S. National Museum; Prof. Kobt. T. Hill.

COPTOSOMA Desor.

COPTOSOMA MORTONI (de Loriol).

- Plate xvn, Figs. la-c.

Cyphosoma Mortoni de Loriol, 1887. Eecueil Zoologique Suisse, Tome iv, No. 3, 

pp. 389-391, PI. xvn, Fig. 2te-c.

Determinative characters. Test circular, depressed. Ambulacra very 

wide, with two rows of primary tubercles, thirteen in each row, the 

three or four at the ambitus large and nearly confluent, but diminishing rapidly in .size toward cither pole; poriferous zones narrow, sinuous; 

pores unigeiniual, those of each pair separated by a granule. Inter - 

ambulacra with two rows of tubercles, nine or ten in each row. Mouth 

opening very large.

Dimensions. Transverse diameter, £ to $ inch; height, £ inch.

Description. The writer has been unable to obtain a specimen of 

this species, but the very full description and excellent figures given 

by de Loriol admit of its satisfactory identification. The description 

that follows is a translation in nearly every particular of that given by 

de Loriol. The two specimens in the possession of de Loriol were so 

deformed that he could not determine the height accurately. The 

test is circular and depressed. The ambulacra! areas are relatively 

very wide, almost as large as the interanlbulacral, and bear two rows 

of large tubercles, thirteen in each row. The first four or five tubercles 

from the apical disk are far apart and very small. At the ambitus 

three or four of the tubercles are very large, with nearly confluent 

areolas (PI. xvn, Fig. Ic), but rapidly diminish in. size toward the 

lower surface, the last four or five being very small and with difficulty distinguished. The areolas, except at the ambitus, are not large.
52 MESOZOIC ECHINODERMATA OF THE UNITED STATES. IBULUOT.

The bosses are finely crenulated and the mamelons small and iinperforate. Upon the lower surface there are large maminillated granules 

which can be with difficulty distinguished from the primary tubercles. 

Each areola is also partially surrounded by a circle of small granules 

that occur most numerously near the line of the central suture. The 

granules are few in number on the upper surface. The poriferous zones 

are narrow, slightly sinuous, and composed of small pores without any. 

increase toward the apical disk or mouth opening. A small granule is 

found between the pores of each pair (PI. xvn, Fig. le).

The interambulacral areas bear two rows of primary tubercles that 

are similar to those of the ambulacra, but larger and less numerous 

(PI. xvn, Fig. la). The lower surface is covered by large mammillated 

granules that can scarcely be distinguished from the tubercles, and 

also by numerous small ones. There are few granules on the upper 

surface. The mouth opening is large, with slight incisions.

Related forms. This species is most closely related to Coptosoma 

speciosum, but in form and in several details of structure is unlike it. 

The presence of granules between the pores of the present species is a 

marked feature.

Locality and geological horizon. This form is from, the Botten limestone 

(upper Cretaceous) of Nahalak, Kemper county, Mississippi.

Collection. P. de Loriol, Switzerland.

COPTOSOMA SPECIOSUM^ Clark. 

Plate xvin, Figs. la-h.

Cyphosoma speciosum Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test circular, inflated at the sides, flattened on the upper and lower surfaces. Ambulacra wide, with two 

rows of primary tubercles, twelve or thirteen in each, that gradually 

diminish in size toward the poles; poriferous zones sinuous; pores unigeminal. Interambulacra with two rows of tubercles slightly larger 

than those of the ambulacra. Mouth opening one-third the diameter 

of the test.

Dimensions. Transverse diameter, ^- inch; height, f inch.

Description. This delicate species has a circular test with inflated 

sides. Both poles are flattened, the lower more than the upper (Pi. 

xvin, Fig. 16).

The ambulacral areas are wide and prominent, and bear two rows of 

large tubercles, twelve or thirteen in each row. The areolas are nearly 

confluent above and below, and are striated by irregular radiating ridges 

(PI. xvin, Fig. I/). The bosses are deeply crenulated, and the small 

mamelons are imperforate. Minute tubercles and granules irregularly 

surround the primary tubercles, occurring in greatest number along 

the central suture. The poriferous zones are slightly sinuous, the 

three pore pairs having a curved arrangement on each ambulacral plate.
CLAKK.] GONIOPYGUS ZITTELL 53

The iuterambulacral areas are about one and one-half times as wide 

as the ambulacral. They have two rows of primary tubercles that are 

somewhat larger than those of the ambulacra (PI. xvm, Fig. Id). The 

areolas are very large and are confluent above and below. Throughout 

the greater part of the column the two rows approach each other, but 

toward the .apical disk are widely separated from one another. The 

smaller tubercles are disposed in rows, with greater or less regularity, 

on either side of the primary series.

The mouth opening is narrow, occupying a little more than one-third of 

the diameter of the test. It has an irregular pentagonal outline. The 

discal opening is large and pentagonal in form (PI. xvm, Fig. la).

Related forms. This form is apparently closely related to Coptosoma 

Mortoni, but is more elevated and does not exhibit the granules between 

the pores.

Locality and geological horizon. This species is from the yellow 

limestone of the middle marl bed (upper Cretaceous) of Timber creek, 

New Jersejr.

Collection. Philadelphia Academy of Natural Sciences.

GONIOPYGUS Agassiz.

GONIOPYGUS ZITTELI Clark.

Plate xvm, Figs. 2 a-d. Plate xix, Figs. 1 a-e.

Goniopygus Zitteli Clark, 1891. Johns Hokins University Circulars, No. 87, p. 76.

Determinative characters. Test subconoidal, circular in circumference; upper surface elevated; base flattened. Ambulacra broad, with 

a double row of alternating tubercles, eighteen to twenty in each series; 

poriferous zones, Avith a double row of pores, multiplied at the peristome. Interambulacra broader than the ambulacra, with a double 

row of primary tubercles, ten to twelve in each row. Apical disk prominent, compact. Mouth opening large, Avith shallow incisions.

Dimensions. Transverse diameter, 1£ inches; height, 1 inch.

Description. All the specimens of this species examined by* the 

writer have a distinctly subconical form that is highly characteristic. 

The upper surface is very much elevated, AAThile the loAver is flat and 

slightly depressed around the mouth edges (PI. xvm, Fig. 2a).

The ambulacral areas are broad, increasing regularly in width from 

the apical disk to the ambitus, beyond Avhich they decrease toAvard the 

mouth opening (PL xix, Fig. Id). There is a double row of eighteen to 

twenty tubercles in each area, that rapidly increase in size from the 

apical disk doAvnward. The pores are arranged in a double roAv on 

each ijoriferous zone except in the vicinity of the mouth edges, Avhere 

they become suddenly increased in number (PL xvm, Fig. 2 1).

The interaulbulacral areas are about one and one-half times the width 

of the ambulacral, and each contains a double row of large tubercles,
54 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BOLL. 97.

ten to twelve in each series (PL xix, Fig. Ic). These tubercles are considerably larger than those of the ambulacra! area, and have wide 

circular areolas, smooth bosses, and imperforate mamelons (PI. xvm, 

Fig. 2c). On the base the tubercles of all the areas are of nearly equal 

size. The miliary space is wide, very nearly smooth in the upper portions of the column, and sparsely covered with granules toward the 

mouth edges.

The apical disk is large and compact, the elongated genital plates 

giving it a star-shaped appearance (PI. xvm, Fig. 2d). The well-defined ocular plates, wedged into the interspaces, make the entire 

outline subpentagonal. Each genital plate is angular at the outer extremity and perforated. On the inner edge of the same there is a 

semicircular depression, in the center of which is a small niammillated 

tubercle.

The mouth opening is large, covering quite one-half the diameter of 

the base. It is divided into ten lobes by ten shallow incisions (PI. xix, 

Fig.lfc).

Related forms. This species shows many points of similarity to 

Echinus patagonensis, described by d'Orbigny in 1842, from the Tertiary 

of southern Patagonia. The margin of d'Orbi guy's species is sharper 

and the apical disk of somewhat different shape. Moreover, if properly referred to the Tertiary, it is undoubtedly a different form. Echinus nndinus, from the desert of Atacaina, described by Philippi in 1860, 

is likewise closely allied to Cr. Zitteli, though more conical and presenting a different surface decoration of the plates. Goniopygus major, 

from the Oeuomanian of Europe, is similar in many particulars, though 

the pores are not increased around the peristome as in G. Zitteli, and 

the anneal disk is of more compact form.

Locality and geological horizon. Goniopygus Zitteli is from the Caprina limestone, a division of the Fredericksburg formation of the 

Comanche series (lower Cretaceous), and has been collected at many 

points in Texas, among others Spanish Oak branch, Williamsou county, 

and Bound Kock.

Collections. TJ. S. National Museum: Texas Geological Survey.

ECHINIDJE.

Test spheroidal. Ambulacra wide, with two or more rows of primary 

tubercles; poriferous zones usually trigeminal or polygeminal. Interanibulacra with two or more rows of primary tubercles, generally of 

equal size with those of the ambulacra. Mouth opening large, decagonal. Apical disk composed of ten plates.
PSAMMECITTNUS CIJTCttJLATUS. 55 

PSAMMECHINUS Agassiz.

PSAMMECHIKTJS CINGULATUS Clark;

Plate xx, Figs. la-i.

PsammecMnus cingnldlus dark, 1891. Johus Hopldiis University Circulars, No. 87, 

P. .

Determinative characters. Test small, hemispherical, with circular 

circumference; sides inflated; upper surface elevated; base1 flattened 

and concave. Ambulacra wide, with two rows of primary tubercles, 

sixteen or seventeen in each series; poriferous zones depressed, trigeminal. Interambulacra about one and one-half times the width of 

the ambulacra; plates covered with, numerous uncrenulated and imperforate tubercles. Mouth opening- large, with ten deep incisions,

Dimensions. Transverse diameter, -| inch; height, % inch.

Description. This delicate form, of which two very perfect specimens 

 were examined by the writer, is hemispherical in shape with circular 

circumference, inflated sides, elevated upper surface, and flattened base. 

In the vicinity of the mouth opening the lower surface is depressed, 

producing a slight concavity.

The ambulacral areas are wide and composed of eighteen to twenty 

plates (PI. xx, Fig. I/). The lower sixteen or seventeen of each series 

bear prominent tubercles that occur in a continuous line to the peristorn e. On either side of the primary tubercles are smaller ones of like 

shape. The three pore pairs are arranged in semicircular form, the 

two upper separated from the lower by one of the secondary tubercles 

(PL xx, Fig. I//).

The interambulacral areas are about one and one-half times as wide 

as the ambulacral and the plates about fifteen in number. Each plate 

bears a large tubercle in the center, a.nd irregularly arranged about it 

smaller tubercles of various sizes (PI. xx, Fig. le).

The mouth opening is large, with ten deep incisions (PL xx, Fig. 17i). 

The apical disk is lacking, but the broken opening is large and pentagonal in form.

Related forms. This unique species is quite unlike any hitherto 

described, and is readily characterized by the arrangement of the 

tubercles and pore pairs. As the only representative of this genus 

recognized in American deposits it has especial interest.

Locality and geological horizon. This species is labeled as simply 

from New Jersey, but in character of preservation is not unlike other 

specimens from, the yellow limestone of the middle marl bed (upper 

Cretaceous) of Timber creek.

Collection. Philadelphia Academy of Natural Sciences.
56 MESOZOIC ECHINODEKMATA OF THE UNITED STATES. [BULL. 97.

STOMECHmUS Desor.

STOMECHINUS HYATTI Clark. 

Plate xxin, Figs. la-e.

Determinative characters. Test high, circumference circular. Ambulacra with four rows of small primary tubercles; poriferous zones wide, 

trigeminal. Interambulaera Avith eigl.it or ten rows of tubercles that 

diminish in number toward apical disk and mouth opening, with a depression along the line of the central suture.

Dimensions. Height, 1 inch; transverse diameter, 1 inch.

Description. The single specimen of this interesting Jurassic form has 

only the cast of a portion of the exterior preserved. The test is high, 

and the circumference circular or slightly subpentagonal. The sides 

rise abruptly from the margin (PL xxin, Fig. la).

The ambulacral .areas are about one-half the width of the interambulacral, and preserve a nearly uniform width throughout. There are 

four rows of tubercles that increase slightly in size from above downward. A depression appears along the line of the central suture. 

The poriferous zones are wide; the pore pairs are placed in oblique 

ranks of three, and each rank is separated from that next to it by two 

small tubercles (PL xxni, Fig. Ib).

The interambulacral area is about twice the width of the ambulacral, 

and the plates of the former are but slightly higher than those of the 

latter (PL xxin, Fig. Ic). Each plate is covered'at the widest part of 

the area with an irregular row of four or five tubercles that are of about 

equal size. The tubercles of the interambulacral areas are of about the 

same size as those of the ambulacral. The tubercles are uncrenulated 

and imperforate. A wide depression extends along the medial line of 

each interambulacral area according Avith the position of the central 

suture.

The regions of the apical disk and mouth opening are largely wanting, but a deep incision shown upon the margin of the latter indicates 

that it is distinctly lobed throughout.

Related forms. The American species shows some points of identity 

with Stomechinus nudus Wright of England, though the latter is less 

elevated, has a sharper marginal angle, and a less regular arrangement 

of the tubercles.

Locality and geological horizon. This species is from the Jurassic 

strata of Taylorsville, California.

Collection. U. S. National Museum.
C-LAKK.] PEDINOPSIS PONDI. 57

PED1NOPS1S Cotteau.

PEDINOPSIS PONDI Clark.

Plate xxi, Figs. la-b. Plate xxn, Pigs. la-c.

Determinative characters. Test large, circular, inflated at the sides, 

convex on the upper surface. Ambulacra with six rows of tubercles at 

the ambitus, the two marginal rows complete and the tour inner incomplete; poriferous zones broad, bigeniinal. Interambnlacrawith twenty 

rows of tubercles at the ambitus, which become reduced to four at the 

margin of the mouth opening; tubercles small, equal, crenulated, and 

perforated. Mouth opening small, with distinct incisions.

Dimensions. Transverse diameter, 3| inches; height, 2^ inches.

Description. The single very large specimen of this species examined by the writer has portions of the test in a very perfect state of 

preservation. The test is Ifirge, circular, inflated at the sides, and convex on the upper surface. The lower surface is flattened, with a slight 

concavity in the region of the mouth opening (PI. xxn, Pig. la). The 

ainbulacral areas are wide, and have at the ambitus six rows of tubercles (PI. xxn, Fig. Ic), the two marginal rows alone continuing from the 

discal opening to the peristome. The four inner rows are incomplete, 

but of equal size with the outer. The tubercles are finely crenulated 

and perforated. The poriferous zones are broad and bigeininal (PI. 

xxii. Fig. Ic), except on the lower surface, where the rows become 

crowded together. Near the mouth, opening they again broaden out 

and become greatly increased in number at the margin. The pores 

are small and round. The inter'ambulacral areas are broad and have 

twenty rows of tubercles at the ambitus, which become reduced to four 

at the mouth edges (PL xxn, Fig. Ib). The tubercles are of equal size 

with those of the ambulacra. Small mammillated granules are found 

scattered over both the ambulacral and interambulacral plates, together with a fine granulation covering the entire surface. '

The mouth opening is small and measures about seven-eighths of an 

inch in diameter. It has ten distinct incisions in the interambulacra. 

The discal opening is partially outlined, but is very indistinct.

This species is named for Mr. Edwin J. Pond, of the TJ. S. Coast and 

Geodetic Survey, by whom the specimen described by the writer was 

discovered.

.Related forms. The present species is unlike any described from 

American or European deposits.

Locality and (jeological horizon. The specimen was.found on the south 

bank of Onion creek, Travis county, Texas, about one-fourth mile southwest of the crossing of the Austin and San Antonio wagon road. It is 

probably from the lower portion of the Austin chalk (upper Cretaceous).

'Collection. Johns Hopkins University.
58 MESOZOIC ECHLtfODERMATA OF THE tJNITEt) STATES. [BdLL.97.

IKKEGULARES. 

ECHINOCONID^E.

Test circular, elliptical, or pentagonal. Ambulacra narrow; poriferous zones unigeminal, seldom bigeminal. Interambulacrabroad; surface 

covered with small, perforated, and crenulated tubercles, that are larger 

on the base. Mouth opening central, circular, or decagonal, with jaws 

and distinct incisions. Apical disk central, composed of ten plates. 

Anal opening between apical disk and mouth opening.

HOLECTYPTJS Desor.

HOLECTYPUS PLANATUS Eoemer.

Plate xxm, Fig. 2a-f.

ffolectypus planatus Roeiner, 1849. Texas, etc., p. 393.

Holectypus planatus Roeiner, 1852. Die Kreidebilduugen von Texas, p. 84, pi. 10,

Fig. 2. , Holectypus planatus Shumarcl, 1852. Eept. Expl. Red River of La., p. 211. 

ffolectypus planatus Giebel, 1853. Jahresber. d. Naturw. Ver. in Halle, p. 373. 

ffolectypus j>l anus Giebel, 1853, ibid. 

Holvciypus planatus Conrad, 1857. U. S. and Mex. Bound. Surv. Rept. vol. 1, pt. 2,

p. 145, pi. 1, Fig. 4.

ffolectypus planatus Desor, 1858. Synop. des fichinides fossiles, p. 174. 

ffolectypus planatus Gabb, 1860. Cat. Invert. Fossils, Cretaceous, p. 18. 

Holectygus planatus Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 2. 

Holectypus planatiis Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test subcircular, sub'conical, flattened ou 

thetinder surface. Ambulacra narrow, straight, and somewhat lanceolate, with six irregular rows of tubercles; poriferous zones straight, 

narrow, unigeminal. Interambulacra wide, plates numerous and narrow, each with a nearly horizontal row of small tubercles' Apical 

disk small, the madreporite large. Mouth opening small, subcircular. 

Anal opening large.

Dimensions. Height, f inch; transverse diameter, 1-| inches.

Description. This very common form, from the Cretaceous of Texas, 

was first reported by Koemer in " Texas," etc.,in 1849, and subsequently, 

in 1852, more accurately defined and figured. ^Although wide differences 

in outline and in the size and arrangements of the tubercles occur? 

they appear to be rather individual"than specific. The majority of the 

specimens are subcircular; in the case of some, however, distinctly circular, while in that of others clearly pentagonal. The ambitus in some 

individuals is sharp, in others, rounded, while the upper surface is distinctly elevated at the center with slightly tumid sides. The under 

surface is flat and slightly depressed in the vicinity of the mouth opening.

The ambulacral areas are narrow, straight, increasing in width toward 

the ambitus and somewhat lanceolate in form. The poriferous zones 

are narrow, the pores small and unigeininal. Six rows of small tuber-
CLARK.] PYRINA PARRYI. 59

cles are found in the broader portion of the areas, which become reduced to .four toward the apical disk and mouth edges (PL xxm, Fig. 2e).

The iuterambulacral areas are about three times the width of the 

ainbulacral at the ambitus. The plates are narrow, each with a horizontal row of small tubercles, five or six in a row at the ambitus, but 

fewer above and below. Each tubercle has a small circular areola, 

crenulated boss, and perforated mamelou. The tubercles cover the 

greater portion of the plates, with minute granules interspersed between them (PL xxm, Fig. 2d). The tubercles are very much larger 

on the lower surface, and the difference in size shown betAveen those of 

the ambulacra and interambulacra on the upper surface disappears.

The apical disk is small. The five ovarial plates are all perforated; 

the madreporite is of large size and indistinctly separated from the 

otker plates (PL xxm, Fig. 2/).

The mouth opening is small, with slight incisions that give a decagonal 

margin. The large oval anal opening extends from the vicinity of the 

mouth edges to the ambitus (PL xxin, Fig. 26).

Related forms. Cotteau has recently described, under the name of 

H. Castilloij a new species of Holectypus from Mexico that is not unlike 

certain individuals of H. planatus examined by the writer. As a sufficient number of intermediate forms has been found to connect all the 

specimens examined Avith the type form described by Koerner, no attempt Ilia's been made to establish new species. H. planus described by 

Giebel is considered such a variation.

Locality and geological horizon. This widely distributed form is from 

the Washita formation of the Oomanche series (lower Cretaceous) of 

Texas. It has been found at Austin, Fredericksburg, and elsewhere.

Collections. U. S. National Museum; Philadelphia Academy of Natural Sciences; Boston Society of Natural History; Texas Geological 

Survey 5 Prof. Eobt. T. Hill.

CASSIDTJLID^E AGASSTZ.

Test circular, oval or subpentagonal. Ambulacra simple or petaloid, generally similar. Mouth opening central or subcentral, generally 

with a pentapetaloid floscelle. Anal opening excentric.

PYEINA Desmoulins emend, de Loriol. 

PYRINA PARRYI Hall. 

Plate xxiv, Figs. Ia-l:

Pyrina Parryi Hall, 1857. U. S. and Mex. Bound. Surv. Kept., vol. 1, pt. 2, p. 144, PI. 1,

Fig. 1-13.

Pyrina Parryi Gabb, 1859. Cat. Invert. Fossils Cretaceous, p. 19. 

Pyrina, Parryi Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 2. 

Pyrina Parryi Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 76.

Determinative characters. Test subpentagonal, broader anteriorly 

than posteriorly, inflated at the sides, flattened above and below.
b() MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

Ainbulacral areas narrow, uuigeminal; both areas covered with minute 

tubercles.

Mouth opening large, elliptical, oblique. Anal opening oval, supramarginal.

Dimensions. Length, 1^ inches j height, | inch.

Description. The two specimens originally described by Hall, in the 

Mexican Boundary Survey Reports, are the only representatives of this 

interesting species that have been examined by the writer. The test 

is regular and symmetrical, slightly pentagonal in outline, enlarged 

anteriorally, contracted posteriorly. The upper surface is convex, 

though somewhat flattened at the summit. The sides are inflated, the 

base flattened and slightly depressed in the vicinity of the mouth opening (PI. xxiv, Figs Ic, Id).

The auibulacral areas are narrow and lanceolate 5 the porifergus 

zones straight and depressed, the pores small, oval, and unigeniinal 

(PI. xxiv, Fig. If). The interanibulacral areas are broad and less elevated than the ambulacral. Both the ambulacra and interanibulacra 

support numerous small tubercles, that are larger and more distinct 

on the lower than the upper surface. Fine microscopic granules are 

disseminated between the tubercles (PI. xxiv, Figs, le, Ig).

The mouth opening is large, elliptical, and obliquely situated slightly 

in front of the center of the base. The anal opening is oval and placed 

nearly in the center of the posterior margin. The apical disk is small, 

composed of four ovarial plates, the large right antero-lateral modified 

to form the madreporite. The five small ocular plates are firmly wedged 

between the ovarial plates (PI. xxiv, Fig. Ik).

Related forms. The species just described is the only representative 

of this genus reported from American strata, and both in form and 

structural features admits of a ready separation from all European 

species. It presents some points of similarity with Pyrina Desmoulinsii 

D'Archiac, but is broader posteriorly and less elevated.

Locality and geological -horizon. Pyrina Parryi Hall is from the 

Washita formation of the Comanche series (lower Cretaceous), and in 

vol. i of the United States and Mexican Boundary Survey Reports is 

reported from Leon Springs, El Paso Road, Texas.

Collection. U. S. National Museum.

BOTRIOPYGUS 33'Orbigny.

BOTBIOPYGUS ALABAMENSIS Clark.

Plate xxv, Figs. la-f.

Botriopygus alabamiensis Clark, 1891. Johns Hoplcins University Circulars, No. 87, 

p. 76.

Determinative characters. Test oblong ; more or less depressed OR 

upper surface, highest anteriorly; under surface concave. Ambulacra 

broad, lanceolate; poriferous zones subpetaloidal above. Interambu-
CLAUK.] " ECHINOBRISSUS EXPANSUS. 61

lacral plates covered with numerous, irregularly distributed tubercles. 

Apical disk anteriorly situated. Mouth opening small, oblique, forward of the center.

Dimensions. Length, 2£ inches; width, 2£ inches; height, 1 inch.

Description. ^The single imperfectly preserved specimen of this species, although apparently lacking some of the characteristics of Botriopygus, is nevertheless referred to that genus. The test is oblong, 

considerably depressed on the upper surface, and concave on the base. 

The apex of the upper surface is forward of the center, making the anterior margin full, the posterior flattened (PI. xxv, Pig. Ic).

The ambulacral areas are broad and lanceolate. They contract appreciably just above the ambitus, giving to the poriferous zones a sub- 

. petaloidal form. The pores of the subpetaloidal portions are large and 

oval, those of the outer rows more elongated than those of the inner 

and acuminated on their inner margins. The pores of each pair are 

united by a furrow. The inner portions of ambulacral plates are covered with tubercles that in the broadest portion of the subpetaloidal 

areas reach five or six in number (PI. xxv, Fig. Ic). Below the subpetaloidal a,reas the pores recede from the outer margin of the plates. 

Those of each pair are close together, small, and nearly round. The 

plates also become broader (PI. xxv, Fig. Id).

The interarnbulacral plates are largn and covered with numerous, 

irregularly arranged tubercles. A microscopic granulation covers the 

intertubercular space (PI. xxv, Fig. I/).

The position of the apical disk is forward of the center of the upper 

surface, although none of the plates are preserved on the specimen examined. The mouth opening is small and obliquely placed slightly in 

front of the center of the base.

Related forms. Gabb describes a species of Botriopygus from. Peru 

under the name of B. elevatus that is not unlike B. alalamensis in many 

particulars, though the American species is larger, less rounded anteriorly, and has a more depressed posterior margin.

Locality and geological horizon. This form is from the Eipley group 

(upper Cretaceous) of Alabama. Its exact locality is unknown.

Collection. Philadelphia Academy of Natural Sciences.

ECHINOBRISSUS Breyn. 

ECHINOBRISSUS EXPANSUS Clark.

Plate xxvi, Figs. la-//. 

Echinol)ns8U8 expanses Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test subquadrate, broader posteriorly, 

moderately convex on upper surface, concave on the base. Ambulacra 

narrowly lanceolate. Anal opening large, supraniarginal; anal sulcus 

broad, deep, extending from near the apex to the ambitus, Mouth 

opening large, situated in front of the middle of the base,
62 MESOZOIC ECHINODERMATA OF THE UNITED STATES. ' [BULL. 97.

Dimensions. Length, 1£ inches; width, 1£ inches; height, £ inch.

Description. This typical Echinobrissus is of moderate size, somewhat depressed above, and subquadrate in marginal outline. The posterior portion is broader than the anterior and distinctly lobed. The 

base is concave.

The ambulacral areas are narrowly lanceolate, and on the upper surface the poriferous zones are subpetaloidal (PI. xxvi, Fig. la). The 

inner rows of pores are round, the outer oval, with acuminated inner 

margins and obliquely placed (PI. xxvi, Fig. I/). The interambulacral 

areas are formed of broad plates that bear numerous small perforated 

and maminillated tubercles. A microscopic granulation covers the 

miliary space (PI. xxvi, Fig. le).

The apical disk is small and compact and the perforations of the 

genital plates distinct (PI. xxvi, Fig. Ig).

The mouth opening is large, excentric, situated at some distance in 

front of the center of the base. The anal opening is large, acuminated 

on the upper margin, and placed in a broad, deep anal sulcus that extends from near the apical disk to the posterior margin (PI. xxvi, 

Fig. Id).

Belated forms. Echinobrissus expansus has no points that would 

closely ally it with any species of this genus hitherto described.

Locality and geological horizon. This species is from the Eipley 

group (upper Cretaceous) of Alabama or Mississippi, but its exact 

locality is not recorded.

Collection. Philadelphia Academy of Natural Sciences.

ECHINOBRISSUS TEXANUS Clark.

Plate xxvi, Figs. 2a-f.

Echinobrissm texanus Clark, 1891. Johns Hopkins University Circulars, No, 87, p. 76.

Determinative characters. Test ovate, rounded anteriorly, subquadrate posteriorly; upper surface convex, apex forward of the center; 

base concave. Ambulacra lanceolate, subpetaloidal. Apical disk forward of the center. Mouth opening small, excentric. Anal opening 

small, oval, in narrow sulcus that begins some distance below the apical 

disk.

Dimensions. Length, f inch; width, f inch; height, -&- inch.

Description. The single specimen of this species is somewhat damaged on the sides, so that the ambital outline is not complete. It is 

ovate in form, broader posteriorly, and subquadrate. The upper surface is convex, but more or less compressed. The lower surface is concave.

The ambulacra! areas are narrowly lanceolate. The poriferous zones 

for a short distance from the apical disk are subpetaloid in form. The 

posterior ambulacra are much longer than the others, the unpaired 

ambulacrum being the shortest. The pores of each plate are oval and 

set at an angle to one another (PI. xxvi, Fig. 2e).
CLAKK.] TREMATOPYGUS CRUCIFER. 63

The interainbulacral plates are large and covered with irregularly 

arranged tubercles. Between the tubercles a microscopic granulation 

covers the surface (PI. xxvi, Fig. 2/).

The apical disk is small and situated forward of the apex. The individual pla,tes can not be fully distinguished on the specimen examined. 

The mouth opening is apparently small, though somewhat obscured. 

It is situated forward of the center of the base.

The anal opening is small, placed in a narrow sulcus that begins some 

distance posterior to the apical disk.

Related forms. UcMnobrissus texanus is readily separated from E. 

expansus by its ovate form and the shape and size of the anal sulcus. 

It is unlike any European species.

Locality and geological horizon. This form is from the Austin chalk 

(upper Cretaceous) of the south bank of the Colorado river, Austiu, 

Texas.

Collection. U. S. National Museum.

TKEMATOPYGUS d'Orbigny. 

TREMATOPYGUS CRUCIFEE, (Morton).

Plate xxvii, Figs. la-i.

Ananohytes cruciferus Mortou, 1830. Am. Jour. Sci., 1st scr., vol. 18, p. 245, PI. 3,

Fig. 8. 

Ananchytes cruciferus Morton, 1830. Philadelphia Acad. Nat. Sci., 1st ecr., vol. 6, pp.

201, 202.

Nucleolites crucifer Morton, 1833. Am. Jour. Sci., 1st ser., vol. 23, p. 294. 

Nucleolites eritcifer Morton, 1834. Synop. Organ. Remains, Cretaceous, p. 75, PI. 3,

Fig. 15.

Nucleolites cruciferus Agassiz, 1840. Cat. Syst., p. 4.

Nucleolites cruciferus d'Orbigny, 1847. Prodrome, vol. 2, p. 271, Etage 22, No. 1197. 

Nucleolites cruciferus Agassiz and Desor, 1847. Cat. rais., p. 97. 

Nucleolites crucifer Broun, 1848. Index Pal., vol. 1, p. 818. 

Pyyorliyncluis crucifer Ravenel, 1850. Am. Assoc. Adv. Sci. Proc., p. 160. 

Trematopyyus crucifer d'Orbigny, 1853-'60. Pal6ont. fraiifaiso, vol. 6, p. 387, PI. 953,

Figs. 10, 11; PI. 963, Figs. 1-5.

J3chinol)ri88U8 cruciferus d'Orbigny, 1854. Revue zool., p. 25. 

Nucleolites crucifer Desor, 1858. Synop. des fichinides fossiles, p. 262. 

Ni(deolites mitifer Gabb, 1859. Cat. Invert. Fossils Cretaceous, p. 19. 

Nucleolites crucifer Meek, 1864. Smith Misc. Coll., vol. 7 (177), p. 2. 

Nucleolitcs crucifer Cook, 1868. Geol. of New Jersey, p. 377. 

Nucleolites crucifer Conrad, 1868. Geol. of New Jersey, App., p. 722. 

Nucleolites cruciferus Credner, 1870* Zeitschr. d. deutsch. geol. Gesells., xxn, p. 217. 

%rematopy(jus crucifer Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test ovate, inflated at the sides and base 

and slightly contracted anteriorly. Aubulacra long, well denned; pores 

uiiigeminal, prominent on the upper surface, indistinct on the base. 

Apical disk situated anteriorly. Mouth opening large and oblique. 

Anal opening large, oval, supramargmal.

Dimensions. Length, 1 inch; breadth, § inch; height, -fa inch.

Description. This urchin is not uncommon at Timber creek, New 

Jersey, where many very perfect specimens ha,yG been obtained. Its
64 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

outline is ovate and very regular, lacking at the ambitus or apex any 

sharply defined angularity. The sides are highly inflated, together 

with the outer portion of the base.

The ambulacral areas are long, lanceolate, and unequal; the posterior 

pair are the longest, the unpaired anterior area is the shortest. The 

areas do not produce any irregularity in the outline of the test beyond 

inconsiderable depressions in the immediate vicinity of the mouth edges. 

The poriferous zones are clearly marked on the upper surface, and the 

pore pairs are nearly horizontal (PI. xxvn, Fig. I/), but toward the 

ambitus the pores become smaller, those of each pair nearer together, 

and the pairs obliquely situated at the lower, outer corner of each plate 

(PI. xxvii, Fig. le); near the mouth edges they again become larger and 

slightly increased in number.

The interambulacral areas, are wide and composed of large plates 

that are bent in the middle. The surface is covered with irregular 

rows of tubercles that are perforated and inammillated. The miliary 

space in its turn is covered with numerous minute and irregularly distributed granules.

The apical disk is small and anteriorly situated; the four genital 

plates are distinctly perforated, those of the anterior pair situated much 

nearer together than those of the posterior (PI. xxvii, Fig. !</).

The mouth opening is large, oblique, and placed somewhat forward of 

the center of the base. The anal opening is large, oval, and acuminate 

at the upper extremity. It is situated in an anal sulcus, that makes a 

marked indentation in the posterior margin, and is bordered by two 

well defined ridges (PL xxvii, Fig. Id).

Eelated forms. Trematopygus crucifer (Morton) is a unique species 

that affords no closely allied forms in either American or European 

deposits. It is the single representative of this genus recorded from 

American strata.

Locality and geological horizon. The only specimens of this form 

thus far reported are from the yellow limestone of the middle marl 

bed (upper Cretaceous) of Timber creek, New Jersey.

Collections. American Mu seum of Natural History, New York; Philadelphia Academy of Natural Sciences; Johns Hopkins University.

CATOPYGTJS Agassiz.

CATOPYGUS OVIFORMIS Conrad.

Plate xxvii, Figs. 2a-f.

Catopygus oviformis Conrad, 1847. Philadelphia Acad. Nat. Sci. Jour., 2d ser., vol.

2, p. 39, PI. 1, Fig. 9.

Nucleolites oviformis (Catopygus; Conrad, 1868. Geol. of New Jersey, App., p. 722. 

Catopygus oviformis Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test ovate, broader posteriorly; upper 

surface nearly flat; apex posterior to apical disk. Ambulacra narrow, 

subpetaloidal. Interambulacra. wide; single interainbulacrum elevated,
CLABK.] CATOPYGUS PUSILLUS. 65

Apical disk excentric, nearer the anterior border. Month opening small, 

excentric, nearer the anterior margin. Anal opening oval, situated in a 

narrow sulcus, that terminates above in a projecting arch.

Dimensions. Length, £ inch; width, f inch; height, £% inch.

Description. The test of this very beautiful little form is ovate, with 

rounded, inflated sides and elevated upper surface. The base is nearly 

flat, slightly concave in the vicinity of the mouth edges, and lobed posteriorly.

The ambulacral areas are narrowly lanceolate, subpetaloidal on the 

upper surface, the two posterior areas being much longer than the 

others. The plates in the petaloidal portions are narrow, but beyond 

increase in breadth (PI. xxvn, Fig. 2e).'

The large interambulacral plates are covered with minute tubercles, 

between which are numerous microscopic granules.

The apical disk is small, excentric, and situated far anterior to the 

apex (PI. xvu, Figs. 2«, 2c).

The mouth opening is small and situated nearer the anterior margin,

The anal opening is oval and placed at the upper part of a nearly vertical anal sulcus. The upper margin of this sulcus forms a beak-shaped 

prominence that overhangs the opening (PI. xxvii, Fig. 2d).

Related forms. It is separated from C. pusillus Clark, the other 

American species, by its narrower outline, more inflated sides, and the 

anterior position of its apical disk. In form it is somewhat like G. 

columbarius, which is widely distributed in the Ceuomanian of Europe, 

but the position of the apical disk at once distinguishes it.

Locality and geological horizon. This species is from the yellow 

limestone of the middle marl bed (upper Cretaceous) of Timber creek, 

New Jersey.

Collection. Philadelphia Academy of Natural Sciences.

CATOPYGUS PUSILLUS Clark. 

Plate xxvii, Figs. 3a-d.

Catopygus imsillus dark, 1891. Jolms Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test ovate to subquadrate, rounded anteriorly, subquadrate posteriorly, broader behind than before; upper 

surface elevated; base concave. Ambulacra narrowly lanceolate, subpetaloidal on the upper surface. Apical disk small, nearly central. 

Mouth opening small, anteriorly placed. Anal opening oval, in vertical 

sulcus beneath overhanging arch.

Dimensions. Length, f- inch; width, -^ inch; height, f inch.

Description. All the specimens of this species examined by the writer 

are casts, that are, however, sufficiently well preserved to admit of the 

determination of all the more important characters. The test is ovate 

to subquadrate, occasioned by the slight angularity of the posterior 

margin. The anterior portion is regularly rounded. 

97 5
66 MESOZOIC ECHINQDERMATA OF THE UNITED STATES. [BULL. 97.

The ambulacral areas are narrow, the posterior pair only slightly 

longer than the anterior. 

 The interainbulacral areas are wide and composed of lai'ge plates.

The apical disk is small and situated nearly in the center of the upper 

surface. '

The mouth opening is small and placed forward of the center of the 

base. The anal opening is situated in a nearly vertical sulcus that 

is overhung at its upper extremity by a projecting arch (PI. xxvii, 

Fig. 3c).

Related forms. Catopygus pusillus is separated from C. oviformis by 

its broader and slightly subquadrate form, less- rounded sides, and 

nearly central position of the apical disk.

Locality and geological horizon. Catopygus pusillus is from the lower 

marl bed (upper Cretaceous) of Wordills, Monrnouth county, New Jersey.

Collection. U. S. National Mnseum.

CASSIDULUS Lamarck.

CASSIDULUS IXOREALIS (Morton).

Plate xxvin, Fig. la-l.

Clypeaster sp. Morton, 1830. Philadelphia Acad. Nat. Sci. Jour., 1st ser., vol. 6, p. 202. 

Clypeaster florealis Morton; 1833. Amer. Jour. Sci.,. 1st ser., vol. 23, p. 294. 

Clypeaster florealis Morton, 1834. Syuop. Organ. Remains Cretaceous, p. 76, PI. 3, Fig.

12, and PI. 10, Fig. 12.

Pygurus florealis Agassiz and Desor, 1847. Cat rais., p. 141. 

Clypeast&r floreali* Bronn, 1848. Index Pal., p. 312. 

Faujasia florealis d'Orbigny, 1853-;60. Pale~ont. francaise, vol. 6, p, 319, PI. 920,

Figs. 5,6.

Faujasia florealis Desor, 1858. Synop. des Echiuides fossiles, p. 318. 

Clypeaster florealis Gabb, 1859. Syuop. Invert. Fossils, Cretaceous, p. 18. 

Cassidulus florealls Meek, 1864.' Smith Misc. Coll., vvol. 7 (177), p. 2. 

Pygurus florealis Conrad, 1868. Geol. of New Jersey, App., p. 722. 

Cassi&ulus florealis Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test subconoidal in outline, subpentagonal, slightly longer in the antero-posterior diameter than the lateral, 

rounded anteriorly, angular posteriorly; apex slightly forward of the 

center. Ambulacra narrow; poriferous zones petaloidal on the upper 

two-thirds of the dorsal surface. Interambulacra wide, covered with 

small perforated tubercles. Apical disk small, situated anteriorly. 

Mouth opening pentagonal, with well-developed floscelle. Anal opening 

supramarginal, in short, narrow sulcus.

Dimensions. Length, If inches; breadth, \\ inches; height, £ inch.

Description. This species, the earliest of this genus recognized from. 

American deposits, has a subconoidal test of moderate height, with a 

subpentagonal margin. The angularity is more pronounced posteriorly than anteriorly, the anterior portion of the margin being distinctly rounded, The antero:posterior diameter is but slightly greater
CLARK.] CASSIDULUS FLOEEALIS. 67

than the lateral, while the height is a little more than one-half of the 

same. The apex is a short distance in front of the center of the upper 

surface, the slope of the anterior face being sharper than the posterior 

(PI. xxvni, Fig. Ic).

The ambulacral areas are narrow. The poriferous zones consist of a 

double row of pores that are arranged in petaloidal form on the 

npjper two-thirds of the dorsal surface, and as phylloidal expansions in 

the vicinity of the month edges (PI. xxvm, Fig. le). In the petaloidal 

portion the pores of the inner row are oval, those of the outer elongated, and each, pair united by a shallow furrow (PL xxvui, Fig. I/). 

Toward the margin the pores are smaller and placed near together 

(PL xxvni, Fig. 1#), and so continue until near the peristome, when 

the poriferous zones suddenly expand. At this point the pores increase 

in size and distance from one another. Between the oral lobes the poriferous zones again suddenly contract.

The interambulacral areas "are of unequal width; the anterior pair are 

the narrowest; the three posterior are of about equal width and nearly 

one-half wider than the anterior. The surface of the plates is irregularly covered with numerous small perforated tubercles with sunken 

areolas, between which are numerous microscopic granules (PL xxvni, 

Fig, It).

The apical disk is composed of four perforated genital and five small 

ocular plates. The fifth genital is apparently obsolete, as it could not 

be observed ,,on any of the several very .perfect specimens examined. 

The large right antero-lateral genital plate, the madreporite, extends 

across the disk, forming a large portion of the center of that body (PL 

xxvni. Fig. Ij).

The mouth opening is large, pentagonal, and slightly nearer the 

anterior margin. It is surrounded by five prominent lobes, that project over the oral opening. Between the lobes the ambulacra are contracted and beyond the same expand to form wide phylloidal areas. 

The peculiar, somewhat star-shaped, form thus produced has been 

termed floscclle by Desor (PL xxvni, Fig. 1&).

The anal opening is small, circular, and supra-marginal, and is situated 

in a short, narrow sulcus (PL xxvni, Figs. la-Id}.

Related forms. Cassidulus florealis is allied to G. mquoreus, though 

the latter is more depressed and more elongated. C. subconicus presents some points of similarity, but has a more sharply defined pentagonal outline, a differently situated anal opening, and more elongated 

pores in the outer rows of the petaloidal areas.

Locality and c/eological horizon. This species is reported from the 

lower marl bed (upper Cretaceous) of New Jersey and Delaware.

Collection. Philadelphia Academy of Natural Sciences.
68 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

'CASSIDULUS ^QTJOEETJS Morton. 

 Plate xxix, Figs. la-i.

Cassidulus ccquorcus Morton, 1834. Synop. Organ. Kemaius, Cretaceous, p. 76, PI. 3, Fig.

14.

Cassidulus cequoreus Desmoulins, 1837. Etudes sur los Echinides, p. 146. 

Cassidulus cequoreus Agassiz and Desor, 1847. Cat. rais., p. 141. 

Cassidulus cequoreus d'Orbigny, 1847. Prodrome, vol. 2, p. 271. 

Cassidulus a}q^loreus Bronn, 1848. Index Pal., vol. 1, p. 244. 

Cassidulus wquorcus d'Orbigny, 1853-;60. Pale"ont. francaise, vol. 6, p. 329, PI. 926, Fig.

6-12.

Cassidulus cvquoreus Desor, 1858. Synop. des Echinides fossiles, p. 290. 

Cassidulus ceqnorum Gab b, 1859. Cat. Invert. Fossils, Cretaceons, p. 18. 

Cassidulus cequoreiis Meek, 1864. Smith Misc. Coll., vol. 7 (177), p. 2. 

Cassidulus (equorcus Conrad, 1868. Geol. of New Jersey, App., p. 722.. 

Cassidulus mqiioreus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test subpentagonal, depressed; upper surface convex; under surface concave, slightly rostrated posteriorly; 

apex forward of the center. Ambulacra narrow; poriferous zones petaloidal on the upper surface; contracted above the margin and expanded 

again on the lower surface, much narrowed at the peristome. Interambulacra wide, covered with small perforated tubercles. Apical disk 

small, situated forward of the center. Mouth opening small, with floscelle. Anal opening supramaTginal, in short sulcus.

Dimensions. Length, 1£ inches; width, 1£ inches; height, f inch.

Description. This typical Cassidulus, early recognized as such by 

Dr. Morton, has a depressed test, subpentagonal in outline. It is 

longer in the antero-posterior diameter than the lateral. The upper 

surface is convex, with sharp marginal edges, while the lower surface 

is flat, with a slight concavity toward the center. The apex is somewhat anterior to the center.

The ainbulacral areas are narrow. The poriferous zones are unigeininal, the pores of the upper part of the dorsal'surface arranged in petaloidal form. At a point varying in ,the different areas from onequarter to one-third of the distance from the margin to the apical disk, 

the zones are contracted and continue as narrow bands over the margin and to the vicinity of the peristome, where they broaden again perceptibly, becoming finally much contracted at the margin of the oral 

opening (PI. xxix, Fig. le). The pores are distinct in the petaloidal 

portion (PL xxix, Fig. If) and in the broadened area near the peristome (PI. xxix, Fig. 1#), but in the intermediate contracted portion 

are small and indistinct. The interambulacral areas are broad, and 

covered by small perforated tubercles with sunken areolas.

The apical disk is comprised of four perforated genital and five small 

ocular plates. As explained under the previous species, the fifth genital is obsolete (PI. xxix, Fig. Ih).

The mouth opening is pentagonal and surrounded by a well-developed
CLABK.] CASSIDULUS MICROCOCCUS. 69

floscelle. The oral lobes are very prominent and the ambulacral furrows 

much contracted (PI. xxix, Fig. li).

The anal opening is situated in a short sulcus on the upper surface 

(PI. xxix, Figs. la-Id).

Related forms. This species is separated from the preceding, with 

which it has much in common, by its more depressed and elongated 

form. From G. micrococcus it is separated by its sharper a,pex, more 

angular margin, the position of the anal opening, and the shorter pore 

openings in the outer rows.

Locality and geological horizon. This species is reported from the 

Eipley group (upper Cretaceous) of Alabama. No more definite statement as to the locality is given.

Collection. Philadelphia Academy of Natural Sciences.

CASSIDULUS MICROCOCCUS Gabb. 

Plate xxx, Figs. la-i.

Cassidulus micrococcus Gabb, 1860. Philadelphia Acad. Nat. Sci. Proo., p. 51.9. 

C(i88id'iilu8 micrococcus Clark, 1891. Johns Hopldns University Circulars, No. 87, p. 76.

Determinative diameters. Test oval, rounded anteriorly, slightly rostrated posteriorly; upper surface convex, flattened at the apex; sides 

equally declining. Ambulacra moderately broad; poriferous cones 

petaloidal on dorsal surface; outer row of pores slit-like in petaloidal 

portion. Mouth opening small, pentagonal, with floscelle. Anal opening oval, situated high on upper surface, in long, narrow sulcus.

Dimensions. Length, If inches; width, 1£ inches; height, f inch.

Description. This species has a distinctly oval form, wider posteriorly. The upper surface is elevated at the margin, but somewhat flattened at the apex. The sides decline very nearly equally. The base 

is flattened, with a slight concavity at the mouth edges. The posterior 

margin is truncated and slightly rostrated.

The ambulacral areas a.re rather broad, contracted about one-quarter 

of the distance from the ambitus to the apex, and narrowed nearly to the 

peristome, where they are again broadened to form indistinct phylloidal 

areas (PI. xxx, Figs. If, Ig). The pores are slit-like in the outer rows 

of the petaloidal portion (PL xxx, Fig. If).

The interambulacral plates are covered with minute tubercles, with 

sunken areolas, that increase in size and number on the base (PL xxx, 

Fig. li).

The apical disk is situated slightly in front of the center of the 

upper surface. The right, anterior genital plate, which is modified to 

form the madreporite, is very large. The posterior genital is not developed, or if present the suture is obscured (PL xxx, Fig. 1/t).

The anal opeifing is oval, situated high upon the upper surface, in a 

long, narrow, and deep sulcus (PL xxx, Figs, la, Id).

Related forms. A comparison of this species with Cassidulus
70 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BOLL. 9?.

retis, as made also by Gabb in his original description, shows that the 

present form is much larger and more oval, and that the anal opening is 

situated higher and in a deeper and longer sulcus, and, furthermore, 

that the pores of the outer row in the petaloidal portion are elongated 

and slit-like.

Locality and geological horizon. This species is from the Ripley group 

(upper Cretaceous) of Eufaula, Alabama.

Collection. Philadelphia Academy of Natural Sciences.

CASSIDULTJS SITBQTJADKATTJS Conrad. 

Plate xxxi, Figs. 1 a-h.

Cassidulus sulquadratm Conrad, 1860. Philadelphia A cad, Nat. Sci. Jour., 2d ser.,

vol. 4, p. 291, PI. 47, Fig. 19. 

Cassidulus subquadratus Clark, 1891. Johns Hopkius University Circulars, No. 87,

p. 76.

Determinative characters. Test subquadrate to subpentagonal. hemispherical; sides equally declining, upper surface convex; lower surface 

concave; posterior margin truncated and rostrated. Poriferous zones 

broadly petaloidal on upper two-thirds of the dorsal surface; sharply 

contracted at lower margin of petaloidal areas. Mouth opening small, 

pentagonal, with well-defined floscelle. Apical disk large, slightly 

anterior to the center. Anal opening round, in deep sulcus.

Dimensions. Length, 2£ inches; width, 2 inches; height, 1 inch.

Description. This remarkably symmetrical Cassidulus has a nearly 

hemispherical form. In outline it is nearer subpentagonal than subquadrate, due to the rostrated character of the posterior margin, which 

is at the same time truncated. The anterior margin is rounded. The 

lateral edges are nearly parallel, though somewhat more approximated 

anteriorly. The apex is slightly forward of the center.

The ambulacral areas are moderately wide in the petaloidal portion, 

narrow beyond. The poriferous zones are composed in the petaloidal 

portion of an inner row of small, nearly circular pores and of an outer 

row of oblique slit-like openings. The pores of each pair are united by 

a shallow furrow (PI. xxxi, Fig. I/). Beyond the petaloidal areas the 

narrow plates of those portions give place to broad plates, each with a 

pair of small, round pores in the lower and outer corner (PI. xxxi, Fig. 

Ic). In the vicinity of the peristome the poriferous zones expand and 

the pores increase in size, though apparently reduced in number (PI. 

xxxi, Fig. Ig). The last pair of plates are much contracted.

The interainbulacral areas are wide. The plates are covered with 

minute tubercles with depressed areolas, which become larger and more 

prominent on the lower surface.

The apical disk is large, composed of four perforated genital and five 

ocular plates. The fifth genital is apparently obsolete (PI. xxxi, 

Fig. 1/0.
CASSIDULUS SUBCONICUS. 7l

The month opening is small, pentagonal, and surrounded by a welldeveloped floscelle. The anal opening is round and situated high 

above the margin, in a deep snlcns, that becomes narrower and shallower toward the ambitus.

Related forms. This species is most closely related to Cassidutils 

subconicuSy'bnt the latter is much more elevated, while the anal opening 

is situated higher and in a less depressed sulcus than in G. subqiiadratus.

Locality and geological horizon, This form is from the Kipley formation (upper Cretaceous) of Mississippi. The specimen described, is from 

Holly Springs, and was collected by Mr. W. J. McGee.

Collection. U. S. National Museum.

CASSIDULUS SUBCONICUS Clark. 

Plate xxxii, Figs, la-it.

Casaiduliie sulconlcus Clarlc, 1891. Jolms Hopldus University Circulars, No. 87, p. 76.

Determinative characters. Test subconical; margin subpentagonal, 

truncated and rostrated posteriorly; apex anteriorly placed. Ambulacra broad in petaloidal portion, narrow beyond; poriferous zones 

unigeminal, pores with slit-like openings in outer row of petaloidal 

areas. Apical disk large, anteriorly situated. Mouth opening subcircular, with very prominent floscelle. Anal opening large, situated high 

on upper surface in shallow sulcus.

Dimensions. Length, 1£ inches; width, 1$ inches; height, 1£inches.

Description. The outline of this form is so similar to the one preceding that there was some hesitation, at first, in establishing it as an independent species. More careful examination of numerous specimens of 

each species has proved the constant occurrence of the individual differences. Cassidulus subconicus is, as its name signifies, subconical. In 

marginal outline it is subpentagonal, the posterior border more or less 

rostrated and clearly truncated. The apex is slightly forward of the 

center, giving a somewhat sharper slope to the anterior portion of the 

test than to the posterior.

The ambulacral areas are broad in the petaloidal portion, beyond 

which they are narrowed. At the margin they again acquire considerable width, but gradually contract beyond, although expanded for a 

short distance in the phylloidal area near the mouth opening (PI. xxxii, 

Fig. le). At the peristome the final pair of plates is highly attenuated 

(PI. xxxii, Fig. !</). The pores of the outer rows, in both the petaloidal 

and phylloidal' areas, are in a marked degree elongated. In the intermediate portion of the column they are small and indistinct.

The interambulacral areas are more prominent than the ambulacral, 

which are slightly depressed. The surface is covered with minute 

tubercles and a microscopic granulation (PI. xxxir, Fig. li).

The apical disk is large, and composed of four perforated genital
72 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

plates and five ocular plates. The fifth genital is apparently obsolete 

(PI. xxxii, Fig. Ifc).

The mouth opening is large, subcircular, and surrounded by a very 

prominent floscelle (PI. xxxn, Fig. Ih). The anal opening is large, 

circular, and is situated high above the margin in a shallow sulcus.

Belated forms. Gassidulus subconictis is closely related to G. subquadratus, but is separated from it by its high subconical test, more 

elevated anal opening, and shallow anal sulcus.

Locality and geological horizon. Like the preceding species, Cassidulus subconicus is from the Eipley group (upper Cretaceous) of Mississippi.

Collection. U. S. National Museum.

CASSIDULTJS POBRECTUS Clark.

Plate xxxin, Figs. Ia-b; Plate xxxiv, Figs. lo-&; Plate xxxv,

Figs. la-d.

Cassidulus porrectus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 76.

Determinative characters. Test very large, subcircular, oval, depressed; upper surface convex; lower surface concave; broader posteriorly than anteriorly; apex forward of the center. Ambulacra broad. 

Ihterambulacra thickly covered with minute tubercles. Apical disk 

small, forward of the center. Mouth opening large, subconical, with 

prominent floscelle. Anal opening supra-marginal, in short shallow 

sulcus.

Dimensions. Length, 4 inches; width, 4 inches; height, 2 inches.

Description. This very large Cassidulus, with one exception the 

largest Echinoid in the American Mesozoic, has an irregularly oval, 

depressed test, that is subcircular in marginal outline. The breadth is 

equal to the length, but is greatest in the posterior portion, so that the 

margin appears contracted anteriorly. The apex is some distance forward of the center and slightly flattened. The posterior margin is 

feebly truncated. *

The ambulacral areas are wide; the contractions below the petaloidal 

region and above the phylloidal continue for short distances, while the 

lowest pair of plates in the column- bordering the mouth opening are 

long and greatly attenuated (PI. xxxv, Fig. la). The pores of the 

outer rows are slit-like in form and obliquely placed (PI. xxxv, Figs.

1&, Ic). 

The interambulacral areas are prominent; the plates are covered with

numerous small tubercles, with depressed areolas, which are larger and 

more prominent on the under than the upper surface (PI. xxxin. Fig. 

Id). The apical disk is small and is placed forward of the center.

The mouth opening is large, subcircular, with very prominent floscelle. The oral lobes project far beyond the level of the base and are 

separated by deep ambulacral furrows (PI. xxxiv, Fig. la).
CLARK.] CASSIDULUS STANTONI. 73

The anal opening is large, oval, and is situated a,t the head of a 

short, narrow sulcns (PI. xxxin, Figs, la, 1&).

Related forms. Gassidulus porrectus is from its size, form, and details of structure readily separated from the other species of Cassidnlus 

described from the American and European Mesozoic.

Locality and geological horizon. Gassidulus porrectus is from the 

Bipley group (upper Cretaceous), of Eufaula, Alabama. In the preliminary report, published in the Johns Hopkius Circulars, the writer 

incorrectly cites Mississippi as the locality.

Collection. U. S. National Museum.

CASSIDULUS STANTONI Clark. 

Plate xxxv, Figs. 2a-d.

Cassidulus Stantoni Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 76.

Determinative characters. Test small, subovate, elevated; up"per 

surface convex, lower surface concave; apex forward of the center. 

Ambulacra very narrow. Apical disk small, forward of the' center. 

Month opening small, with floscelle. Anal opening high above margin, in long, narrow, and deep sulcus.

Dimensions. Length, f inch; Avidth, £ inch; height, £ inch.

Description. This minute Cassidulus has a suboA^ate test, an eleA^ated, 

convex upper surface and a concave lower surface. It is broader posteriorly than anteriorly, and the posterior margin is truncated. The 

apex is situated slightly anterior to the center of the upper surface 

(PI. xxxv, Fig. 2a).

The ambulacra! areas are very narroAV. The petaloidal portion but 

slightly exceeds the remainder in width, Avhich is nearly equal throughout. The phylloidal region is feebly outlined.

The interainbulacral areas are broad, but the poor state of preservation of the specimens renders it impossible to determine all the details 

of structure.

The apical disk is small and forward of the center, but not sufficiently 

well preserved to distinguish the individual plates. The mouth opening is small and surrounded by a feeble floscelle. The anal opening is 

round and situated high aboA7e the margin, at the head of a narrow, 

deep sulcus (PI. xxxv, Figs. 2a, 2d).

Related forms. Gassidulus Stantoni is quite unlike any other representative of this genus from American strata, and can not be readily 

associated with any European species.

Locality and geological horizon. This species is from the Colorado 

group (upper Cretaceous) of Muddy creek, Huerfano county, Colorado.

Collection. U. S. National Museum.
74 MESOZOIC ECSINODERMATA OP THE UNITED STATES. [BULL. ST.

Test ovate or cordate. Ambulacra narrow; poriferous zones narrow, 

pores unigeminal. Apical disk elongated, at times so much that the 

three anterior ambulacra are widely separated from the two posterior. 

Mouth opening excentric, anteriorly situated. Anal opening inframarginal or marginal.

ANANCHYTES Mercati.

ANANCHYTES OVALIS- Clark.

Plate xxxvi, Fig. la-/t.

Determinative characters. Test subovate cordate; contracted posteriorly; upper surface convex; lower surface flat. Apical disk elongated, consisting of four perforated genital aud five ocular plates 

situated slightly forward of the center. Mouth opening near the anterior margin. Anal opening oval, situated on a slight protuberance 

of the posterior margin.

Dimensions. Length, If inches; width, 1£ inches; height, 1^ inches.

Description. The two specimens of this species collected by the 

writer are remarkably well preserved aud admit of the determination 

of all the essential features. The test is in lateral outline subovate, 

though somewhat cordate in form when viewed from above or below. 

A marked protuberance (PI. xxxvi, Fig. le) is present on the posterior 

margin that appears as a slight ridge on the lower surface between 

the mouth and anal openings. The upper surface is convex. The sides 

are full and rounded at the ambitus. The base is nearly flat, with the 

exception of the slight ridge and depressed mouth edges.

The ambulacra! areas are wide and straight, attaining their greatest 

width just above the ambitus. The pores are oval, and those of each 

pair are placed at an angle to one another (PI. xxxvi, Fig. Ig). The 

surface of both the ambulacral and interambulacral plates is covered 

by small tubercles, between which are numerous microscopic granules. 

The apical disk is elongated (PI. xxxvi, Fig. I/). The four genital 

plates are large and distinctly perforated. The anterior, right-hand 

genital plate, which serves as the madreporite, is much larger thau any 

of the others, being several times the size of the anterior left-hand 

genital, with which it is in contact. The posterior genitals are very 

nearly of equal size.

The mouth opening is transversely oblong and situated near the anterior margin. The anal opening is oval and situated on a marked 

protuberance on the posterior margin.

Related forms. The present species is the only representative of the 

genus recognized from American deposits. It is niore. ovate and less 

elevated than the forms described from European strata.
CLARK.] CARDIASTER CINCTUS. 75

Locality and geological horizon. This species is from the yellow limestone of the middle marl bed (upper Cretaceous) of Vincentown, New 

'Jersey.

Collection. Johns Hopkins University.

OAKDIASTER Forbes.

CARDIASTER CINCTUS Morton.

Plate xxxvn, Figs. la-h.

Spatangus sp. Morton, 1829. Philadelphia Acacl. Nat. Sci. Jour., 1st ser., vol. 6, p. 122.

Anancliytes sp. Morton, 1830. Aiu. Jour. Sci., 1st ser., vol. 17, p. 287.

'Anancliytes cinctus Morton, 1830. Philadelphia Acad. Nat. Sci. Jour., 1st ser., vol. 6,

p. 200. 

Anauchytes fimlriatiis Morton, 1830. Philadelphia Acad. Nat. Sci. Jonr., 1st ser., vol.

6, p. 20(3.

Anancliytes cinctus Morton, 1830. Am. Jour. Sci., 1st ser., vol. 18, p. 246, PI. 3, Fig. 7. 

Anancliytes fimlriatiis Morton, 1830. Am. Jour. Sci., 1st ser., vol. 18, p. 245, PL 3,

Fig. 9. 

Anauchytes cinctus Morton, 1834. Synop. Organ. Remains, Cretaceous, p. 78, PL 3,

Fig. 19. 

Anancliytes fimlriatus Morton, 1834. Synop. Organ. Remains, Cretaceous, pp. 77, 79,

PL 3, Fig. 20.

Holaster cinctus Agassiz and Desor, 1840. Cat. Syst., p. 1. 

Holaster cinctus Agassiz and Desor, 1847. Cat. rais., p. 133. 

Holaster fimlriatus Agassl/, 1847. Cat. rais., p. 141. 

Holaster cinctus d'Orbigny, 1847. Prodrome, vol. 2, p. 269. 

Holaster-fimlriatus d'Orbigny, 1847. Prodrome, vol. 2, p. 269. 

Holaster cinctus Broun, 1848. ludex Pal., vol. 1, p. 593. 

Anancliytes fimlriatus Broun, 1848. Index Pal., vol. 1, p. 70.

Cardiaster cinctus d'Orbigny, 1853-'60. Paldont. fraucaise, vol. 6, p. 147; PL 905, Fig. 4. 

Cardiaster fimlrialus d'Orbiguy, 1853-'60. Paldont. fraucaise, vol. 6, p. 147; PL 905,

Pig. 3. 

Cardiaster cinclus (Cardiaster fimbriatus) Desor, 1858. Syuop. des Hchiuides fossiles,

p. 346.

Anancliytes cinctus Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 18. 

Anancliytes fimlrialus Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 18. 

Holaster cinctus Creduer, 1870. Zeitschr. d. deutsch. geol. Gesells. xxu, p. 218. 

Holasler cinctus Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 77.

Determinative characters. Test cordate, distinctly grooved anteriorly; contracted posteriorly; upper surface convex; lower surface flat. 

Ambulacra wide. Apical disk much elongated, consisting of four perforated genital and five ocular plates situated slightly forward of the 

center. Mouth opening near the anterior margin. Anal opening oval, 

situated on the truncated posterior margin.

Dimensions. Length, 2 inches; width, 2 inches; height, 1£ inches.

Description. This species, which is among the earliest of the Echinoid 

forms recognized from American Cretaceous strata, is distinctly cordiform, with a pronounced groove on the anterior face that is occupied 

by the unpaired ambulacrum. Opposite thereto is a slight ridge at the 

central suture of the unpaired posterior interambulacruin that is sud-
76 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

denly terminated by the nearly vertically truncated surface of the 

posterior margin. The sides decline equally to the ambitus, giving an 

oval outline to the vertical lateral section. The lower surface is nearly 

flat, with the exception of the slight depressions directly at the mouth 

edges and the elevated area extending from the center of the base to 

the posterior margin.

The ambulacral areas are wide, apetaloid, and separated at the apex. 

The antero-lateral pair are bent backward in their upper part, beyond 

which they" extend straight to the margin. The postero-lateral pair 

are bent somewhat forward, after which they extend straight over the 

margin. The single ambulacrum is situated in the deep anterior sulcus. 

The pores of the paired ambulacra consist, in the upper portion of the 

columns, of oblique oval openings united by furrows (PI. xxxvii, Fig. 

I/), while lower down they become small and often indistinct (PI. 

xxxvii, Fig. I/). In the unpaired ambulacrum the pores are extremely 

small.

The surface of the interambulacral as well as of the ambulacral plates 

is covered with fine granules, among which are irregularly scattered 

numerous small perforated tubercles.

The apical disk is narrow, elongated. The four perforated genital 

plates are disposed in pairs, between which two of the five ocular plates 

are situated. Forming the posterior portion of the disk are two moreocular plates, while the fifth plate comprises the anterior part. The 

ambulacral areas are on this account separated at their apices (PI. 

xxxvii, Fig. Ih).

The mouth opening is transversely oblong and is situated near the 

anterior margin of the base. The anal opening is oval and situated on 

the truncated surface at the posterior margin of the test (PI. xxxvii, 

Fig. le).

Belated forms. This species js separated from Holaster simplex, the 

only other closely related form found in American Mesozoic deposits, 

by its deep anterior sulcus and less inflated upper surface.

Locality and geological horizon. Cardiaster cinctus is from the yellow 

limestone of the middle marl bed (upper Cretaceous) of Timber creek, 

New Jersey.

Collections. Philadelphia Academy of Natural Sciences j American 

Museum of Natural History, New York.

HOLASTER Agassiz.

HOLASTER SIMPLEX Shumard.

Plates xxxvin, Figs, la-g; xxxix, Figs. la-d.

Holaster simplex Shumard, 1853. Kept. Expl. Red River of Louisiana in 1852, p. 210,

PI. 3. Fig. 2.

Holaster comanchesi Marcou, 1858. Geol. of North America, p. 40, PI. 3, Fig. 3. 

Holaster simplex Desor, 1858. Synop. des Echinides fossiles, p. 450. 

Holaster comanchesi Desor, 1858. Synop. des Echinides fossiles, p. 449.
CLARK.] HOLASTER SIMPLEX. 77

Jlolastcr simplex Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Holaster comancliesi Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Holnster simplex Meek, 1864. Smith. Misc. Coll., vol. 7, (177), p. 3. 

Holaster comanchesi Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 3. 

Holaster simplex Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 77.

Determinative characters. Test oblong, cordiforni; upper surface 

much elevated, rounded, and grooved on the anterior face; lower surface flat; apex nearly central. Ambulacra wide; pores unigeminal, 

with sli^-like openings in upper portion of the column that become indistinct toward the margin and upon the base. Apical disk compact 

and not greatly elongated. Mouth opening transversely oval, situated 

near the anterior margin. Anal opening large, on truncated posterior 

margin.

Dimensions. Length, 2£ inches; width, 2£ inches; height, 2 inches.

Description. After the most careful examination of a large number 

of specimens the writer has been unable to find any constant characters 

that would warrant the separation of the forms described as Holaster 

simplex and Holaster comancliesi. They are accordingly included under 

the same species. The tesfr is oblong, cordiforra, much elevated, 

rounded above and flattened below. A shallow groove occupies the 

anterior face of the test, producing, a feeble emargination of the anterior ambitus. A slight ridge extends along the line of the central 

suture of the single interambulacrum, which is suddenly terminated by 

the truncated face of the posterior margin.

The arnbulacral areas are wide. The poriferous zones of the paired 

ambulacra are in the case of the posterior pair bent, more or less forward in their upper portions, and in the case of the anterior slightly 

backward. The pores of the paired ambulacra have elongated openings in the upper portion (PI. xxxvm, Fig. Id) and become very small 

and indistinct below (PI. xxxvm, Fig. le). The pores of the unpaired 

ambulacrum are exceedingly small.

The surface of both iiiterambulacral and ambulacra! plates are covered by small tubercles, between which are numerous microscopic 

granules (PI. xxxix, Figs. Ic, Id).

The apical disk is compact and rather short. The four genital plates 

are large and broad. The two interposed oculars are large; the remaining three very small (PI. xxxvm, Fig. I/).

The mouth opening is large, transversely oblong, and situated near 

the anterior margin (PI. xxxvm, Fig. 1&). The anal opening is oval, 

acuminate above, and situated on the truncated posterior border (PL 

xxxix, Fig. 1&).

Related forms. Holaster simplex is separated from Cardiaster cinctus 

by its more elevated upper surface and shallow anterior sulcus. It is 

very like Holaster Icevis, v&r.planus, from the European Cretaceous, but 

is more elevated and distinctly broader posteriorly.

Locality and geological horizon. This species is from the Washita 

formation of the Comanehe series (lower Cretaceous) of Texas, It 19
78 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BOLL. 97.

found in Bell and Bexar counties, and near Fort Worth; also at Preston, Grayson county, on the Eed river and at Austin. It is also 

found near Fort Washita, Indian Territory. 

Collection. U. S. National Museum.

SPATANGIDJE.

Test bilaterally symmetrical, generally cordiform. ambulacra miequal and petaloidal. Apical disk compact. Mouth opening transversely 

bilabiate or pentagonal, situated anteriorly. Anal opening posteriorly 

situated and supra-marginal. Spines of different sizes.

ENALLASTEK D'Orbigriy.

ENALLASTER TEXANUS (Roemer).

Plate xxxix, Figs. 2a-g.

Toxaster texanus Roeiner, 1849. Texas, etc., p. 393.

Toxaster texanus Roemer, 1852. Die Kretdebildungen vou Texas, p. 85, PI. 10, Fig. 3. 

Toxaster ungula Giebel, 1853. Jahresber. des naturw. Vereins in Halle, p. 373. 

Enallaster texasus d'Orbigny, 1853-'60. Fallout, frauoaise, vol. 6, p. 184, PI. 850,

Fig. 1-7. 

Toxaster texanus Conrad, 1857. U. S. ami Mex. Bound. Surv. Rept., vol. 1, pt. 2, p. 145,

PI. 1, Fig. 2«-2c.

Enallaster texanus Desor, 1858. Synop. des fichinides fossilee, p. 358. 

Toxaster texanus Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Toxaster texanus Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 3. 

Enallaster texanus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test oblong, cordiform, broad in anterior 

portion, contracted and truncated posteriorly, with deep anterior 

groove; upper surface convex, elevated; base flat, depressed, at the 

mouth opening; sides rounded; apex excentric and posterior. Ambulacra narrow and unequal, the postero-lateral pair much shorter than the 

others. Apical disk small and compact. Anal opening situated high 

above the margin.

Dimensions. Length, If inches; width, 1^ inches; height, § inch.

Description. The exact limitations of this species have in most of 

the earlier publications been very imperfectly designated. Other 

forms, even one of a different genus, have been included. The test 

is oblong, cordiform, and elevated. The upper surface is convex, with 

a well-defined anterior groove, narrow and slightly depressed at its 

head. On the posterior face the surface is truncated to the margin. 

The sides are rounded and inflated. The base is flat, except for the 

peristomial depression near the anterior margin and the central elevated region extending from th% same to the posterior border.

The ambulacral areas are narrow and very unequal. The anterolateral pair are large and curved backwards in their upper portions. 

The pores are very unequal; those of the anterior zone are small and 

near together, those of the posterior elongated, the external nearly
CLARK.] ENALLASTER TEXANUS. 79

twice as large as the internal series (PI. xxxix, Fig. 2e). There are 

about 35 pairs of pores in the petaloidal portion of each poriferous 

zone.

The postero-lateral pairs are short and quite symmetrical in structure. 

There are 16 pairs of pores in the petaloidal portions of each poriferous 

zone.

The anterior unpaired ambulacrum is situated in the anterior groove, 

and is wider than the other areas. An elongated pore appears in the 

external rows on alternate plates. On the intervening plates the 

small rows are closely approximated (PI. xxxix, Fig. 2/). In the lower 

portion of each column the plates are large and oblong. A pair of minute 

pores occupy the lower outer corner of each.

The surface of the test is* covered with a minute granulation, scattered among which are numerous small tubercles.

The apical disk is small and compact, and the four large genital 

plates are distinctly perforated. The right antero-lateral plate occupies 

the center of the body. The five small oculars are wedged in between 

the genitals (PI. xxxix, Fig. 2g).

The mouth opening is transversely oblong and situated in a depression.

The anal opening is situated high upon the truncated posterior 

margin, and is small and oval, acuminate below (PI. xxxix, Fig. 2d).

Related forms. It seems not improbable that Spatangus columbiamtm, 

described by Lea in 1840, from the United States of Colombia, may 

prove to be identical, or at least very closely related to the Texan 

form. The indistinct figure shows a different arrangement of the pores 

in the antero-lateral ambulacra, but it is doubtful whether it can be depended upon for such details of structure. It seems unwise, however, 

to replace the term texanus when any doubt upon this point still remains.

JBnallaster peruviamis, described by Gabb in 1876, from material obtained from Peru, seems to be identical.

Among the European Enallasters none apparently are closely related 

to Enallaster texanus.

Locality and geological horizon. Enallaster texanus is found widely 

in Texas in the Fredericksbur'g formation of the Comanche series 

(lower Cretaceous). It is characteristic of the Comanche peak horizon.

Collections. TJ. S. National Museum; Texas Geological Survey; Boston Society of Natural History; Prof. Eobt. T. Hill.

ENALLASTER OBLIQUATTJS Clark. 

Plate XL, Figs. la-l.

Determinative characters. Test oval, cordiform; upper surface convex, flattened and depressed anteriorly, elevated posteriorly; lower 

surface flat, with peristomial depression; apex forward of the center. 

Ambulacra narrow, unequal, Surface of the plates covered with small
80 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

tubercles and intervening microscopic granulation. Apical disk compact. Mouth opening transversely subpentagonal. Anal opening situated on truncated posterior margin.

Description. This species has a broad cordiforni test, that is flattened 

.and slanting on the anterior upper surface, whence the name obliqiiatus. 

The anterior groove is deep, wider at its head, and cuts broadly into 

the anterior margin. The posterior portion of the test is elevated near 

the apex and obliquely truncated toward the margin. The sides are 

sloping anteriorly, fuller posteriorly. The base is flat with a deep 

peristomial depression.

The ambulacral areas are narrow and unequal. The antero-lateral 

pair are slightly depressed and curved backwards in the upper portion. 

The pores are unequal, those of the anterior zone small and near 

together, those of the posterior elongated, the exterior much more so 

than the anterior series (PL XL, Fig. I/). There are about forty pairs 

of pores in each zone.

The postero-lateral pair are short and slightly depressed. The 

pores are more nearly equal and about twenty-four pairs are found in 

each zone. The single ambulacrum is placed in the anterior groove 

and is much wider than the paired ambulacra. The pores of the 

different plates vary in size and position (PL XL, Fig. le). The plates 

in the lower portions of the areas are large and oblong in form.

The surface of the test is covered with minute tubercles between 

which is a microscopic granulation. The apical disk is small and coinpact (PL XL, Fig. li).

The mouth opening is transversely subpentagonal (PL XL, Fig. 1/t). 

The anal opening is oval and situated high on the truncated posterior 

margin (PL XL, Fig. Id).

Related forms. Enallaster obUquatus is separated from JE. texanus, 

the only other representative of this genus from the Cretaceous deposits 

of the United States, by its broader more depressed-form, more sunken 

anterior sulcus, and the lower position of the anal opening. It is closely 

related to JH. mexicanus, described by Cotteau, in 1890, from material 

obtained from Mexico.

Locality and geological horizon. This species is from the Fredericksburg formation of the Comanche series (lower Cretaceous) of Texas. 

It is characteristic of the alternating or Glen Eose beds of Austin and 

Glen Kose.

Collections. U. S. National Museum; Texas Geological Survey.

EPIASTEE D'Orbigny.

EPIASTER ELEGANS (Shumard)^

Plate XLI, Figs, la-b; Plate XLII, Figs. !«-&; Plate XLIII, Figs. la-e.

Hemlaster elegans Shumard, 1853. Kept. Expl. Ee.d Eiver of Louisiana in 1852, p, 210, 

PI. 2, Figs. 4o-4c.

r eleyans Ga'blj, 1859, Cat, Invest. Fossils Cretaceous, p. 19.
CLARK.] «> EPIASTER ELEGANS. 81

Tomster elegans Meelc; 1864. Smith. Misc. Coll., vol. 7 (177), p. 3.

Mao-aster texanus Koemer, 1888. Neues Jahrbuch fiir Mm., Geol., u. Pal., Bd. I, pp.

191-195, PI. 6, Figs. 1-4. 

Epiaster elegans Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test large, oblong, cordiform, flattened 

both above and below; sides rounded, with a shallow anterior groove 

and truncated posterior margin. Ambulacra subpetaloidal, depressed; 

poriferous /ones straight, pores with elongated, slit-like openings. 

Apical disk small, compact. Mouth opening transversely oval, situated 

near the anterior margin. Anal opening oval, situated on the truncated 

posterior margin.

Dimensions. Length, 4 inches; width, 3f inches; height, 2 inches.

Description. Eoemer in 1888 established a new genus and species 

(Macraster texanus) for a form that is identical with Hemiaster elegans 

described by Shumard in 1853. The species properly belongs to the 

genus Epiaster. There does not seem to be a sufficiently wide difference between the characters assigned to Macraster and those properly 

belonging to Epiaster to warrant the acceptance of the former genus 

for the present species.

The test is very large and flattened on both the upper and lower surfaces. The sides are round. The groove on the anterior face is shallow 

and cuts the margin lightly. The posterior face is obliquely but not 

broadly truncated.

The ambulacra! areas are nearly equal, depressed, with a distinct 

furrow on the upper surface (PI. XLI, Fig. la). The poriferous zones 

are long, wide, and straight, and the pores consist of slit-like openings 

(PL XLIII, Figs. 1&, lc). The zones are subpetaloidal on the upper surface, reaching quite to the upper margin of the rounded sides. The 

unpaired ambulacrum is narrower than the others; the pores are smaller 

and more closely approximated.

The surface of both areas is covered with minute tubercles, between 

which are microscopic granules (PL XLIII, Fig. Id).

The a.pical disk is small, compact, and consists of four large perforated genital plates and five small oculars (PL XLIII, Fig. le).

The mouth opening is transversely oval and situated near the anterior 

margin (PL XLII, Fig. la).

The anal opening is large, oval, and situated on the truncated face of 

the posterior margin (PL XLII, Fig. 16).

Related forms. Epiaster elegans is most nearly related to E. Whitei, 

the single other American representative of this genus, but is separated 

from it by its great size, its excessively long subpetaloidal areas, and 

the position of the anal opening, which is on an obliquely truncated surface that opens downward, while on E. Whitei it is situated on a vertical 

face that opens upwards.

Locality and geological horizon. Epiaster elegans is from the Washita 

formation of the Oomanche series (lower Cretaceous) of Texas. It is 

Bull. 97 6
82 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BOLL. 97.

characteristic of the Fort Worth limestone, and is fonnd at numerous 

localities between Denison and El Paso.

Collections. U. S. National Museum; Johns Hopkins University; 

Boston Society of Natural History; Texas Geological Survey; Prof. 

Robt. T. Hill.

EPIASTER WHITEI Clark. 

Plate XLIII, Figs. 2a-d-, Plate XLIV, Figs. la-g.

Toxaster elegans Conrsiti, 1857. U. S. and Mex. Bound. Surv. Kept., voL 1, pt. 2, p. 146,

PL 21, Fig. la-e. 1 

Epiaster Whitei Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test small, cordiform; upper surface convex, elevated; lower surface flat; sides, inflated; apex forward of the 

center. Ambulacra moderately broad; poriferous zones petaloidal, 

pores with elongated openings; antero-lateral pair bent slightly backward in upper part. Apical disk oval. Mouth opening transversely 

oval. Anal opening small, oval, situated high on posterior border.

Dimensions. Length, 1£ inches; width, If inches; height, f inch.

Description. This species has been frequently confounded with 

Enallaster texanus and piaster elegans. With the former it has little 

in common beyond a certain similarity in outward form, while the points 

of difference from the latter are less striking and will be shortly stated.

The test is small and cordiform. The upper surface is distinctly 

elevated, the apex occupying a point anterior to the center. The lower 

surface is flat with the exception of the peristomial depression. The 

sides are inflated with a well marked groove at the ceuter of the anterior face and a prominent truncated surface on the posterior margin.

The ambulacral areas are moderately broad.' The poriferous zones 

are subpetaloidal in their upper part, but this feature does not continue 

to the margin (PI. XLIII, Fig. 2c). The pores in the paired ambulacra 

are all of about equal size and equally spaced. In the unpaired ambulacrum they are smaller and nearer together. The autero-lateral pair 

are bent slightly backward in their upper part. They are distinctly 

larger than the postero-laterals.

The interambulacral areas are prominent and the surface of the plates 

covered with minute tubercles and microscopic granules (PI. XLIV, 

Fig. Ic).

The apical disk is small, compact, and consists of four large perforated 

genital plates and five oculars.

The mouth opening is transversely subpentagonal and situated near 

the anterior margin (PL XLIV, Figs. 1&, I/).

The anal opening is small, oval, and situated high on the truncated 

posterior margin (PL XLIII, Fig. 2&).

Related forms. In many particulars Epiaster Whitei is to be closely 

associated with E. elegans. It is, however, more elevated, the ambu-

' Figured under the name of Ilolasler elegant.
CLARK.] HEMIASTER PARASTATUS. 83

lacral furrows are shorter, and the anal opening is differently situated 

as previously mentioned in. the description of the latter species.

Locality and geological horizon. ^piaster Whitei is from the Washita 

formation of the Comanche series (lower Cretaceous) of Texas. It is 

found in the Duck creek chalk of Denison, associated with Hamites 

Fremontii Marcou.

Collection. U. S. National Museum.

HEMIASTER PARASTATUS (Morton). 

Plate XLV, Figs, la-m.

Spaiangus sp. Morton, 1830. Am. Jour. Sci., 1st ser., vol. 17, p. 286.

Spatangua cor-marinum (?) Morton, 1830. Am. Jour. Sci., 1st ser., vol. 18, p. 250, PI.

3, Fig. 10. 

Spatangu8 cor-marinum (?) Morton, 1830. Philadelphia Acad. Nat. Sci. Jour., 1st ser.,

vol. 6, p. 199.

Spatanyusparastatus Morton, 1833. Am. Jour. Sci., 1st ser., vol. 23, p. 294. 

Spatangusparastatus Morton, 1834. Synopsis Organ. Remains, Cretaceous, p. 77, PL

3, Fig. 21.

Hemiaster parastalun Agassiz and Desor, 1847. Cat. rais., p. 141. 

Herniaster parastatus d'Orbigny, 1847. Prodrome, vol. 2, p. 270. 

Spatangus parastatus^onn, 1848. Index Pal. vol. 1, p. 1160. 

Hemiasler parastatits d'Orbigny, 1853-'56, Pale"ont. francaise, vol. 6, p. 265, PL 894,

Fig. 4.

Hemiasler parastatus Desor, 1858. Synop. des l5chinides fossiles, p. 373. 

Hoi aster parastatus Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Hemiasler ( t) parastatus Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 3. 

Hemiaster parastatus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test cordiform, inflated; upper surface 

elevated, with deep groove on anterior surface and sharp ridge posteriorly that is terminated by the flat, nearly vertical, truncated face 

of the posterior margin. Ambulacra! petals depressed, the anterior 

pair twice as long as the posterior. Apical disk small, compact. 

Mouth opening with distinct, overhanging lip. Anal opening small, 

situated high ou truncated surface.

Dimensions. Length, 1£ inches; width, 1£ inches; height, 1£ inches.

Description. This interesting and rather common form has a high, 

cordiform test, with deep anterior sulcus and high posterior ridge ou 

the upper surface, the latter terminated by the high and nearly vertically truncated face of the posterior margin. The sides are rounded 

and inflated. The base is flat, with the exception of the peristomial 

depression.

The ambulacral areas are very unlike. The poriferous zones are 

distinctly petaloidal (PI. XLV, Fig. le). The petals of the posterolateral pair are short and broad. Those of the antero-lateral pair are 

bent backward at their center, depressed, and about twice the length 

of the postero-lateral pair. The pores are slightly elongated (PI. XLV, 

Fig. 1/t). The unpaired ambulacrum is very broad, the poriferous
84 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

zones far apart, and the poms small and approximated (PI. XL V, Fig. If).

The surface is covered with small tubercles, between which are numerous microscopic granules (PL XLV, Figs. If] !</, It, 1Z, andlw).

The apical disk is small and situated posteriorly to the center of the 

upper surface. The four genital plates are distinctly perforated and 

separated by the five small oculars (PL XLV, Fig. In).

The mouth opening is transversely arched and bilabiate. The lower 

lip projects prominently. The anal opening is small and situated high 

on the truncated surface of the0 posterior margin. The peripetalous 

fascicle is broad and distinct (PL XLV, Figs. It, lie).

Related forms. Hemiaster parastatus is most closely related to H. 

ungula, from which, however, it is separated by its deeper and broader 

anterior sulcus, more posterior position of the apical disk, and more 

inflated sides. It is apparently distinct from any of the many species 

described from European deposits.

Locality and geological horizon. If. parastatus is from the yello\\fjlimestone of the middle marl bed (upper Cretaceous) of Timber creek, 

New Jersey, and also from the Eipley group (upper Cretaceous) of 

Alabama.

Collections. Philadelphia Academy of Natural Sciences; American 

Museum of Natural History, New York; Johns Hopkius University.

HEMIASTER Desor.

HEMIASTER STELLA (Morton).

Plate XLvi, Figs. la-d.

Spatanfjus stella Morton, 1830. Am. Jour. Sci.; 1st ser., vol. 18, p. 245, PI. 3, Fig. 11. 

Spatangus stella Morton, 1830. Philadelphia Acad. Nat. Sci. Jour., 1st ser., vol. 6, p.

200.

Spalangus stella Morton, 1834. Synop. Organ. Remains Cretaceous, p. 78, PI. 3, Fig. 18. 

Hemiaster stella Agassiz and Desor, 1847. Cat. rais., p. 141. 

Hemiaster stella Desor, 1858. Syuop. des Echinides fossiles, p. 373. 

Hemiaster stella Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Hemiaster (?) stella Meek, 1864. Smith Misc. Coll., vol. 7 (177), p. 3. 

Hemiaster Welherbyi de Loriol, 1887. Eecueil Zoologique Suisse, f. 4, pp. 391-394, PL

17, Figs. 5-8. 

Hemiaster incrassatus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test small, oval, cordate, inflated, rounded 

before, truncated behind; upper surface elevated posteriorly, sloping 

anteriorly; anterior groove short, not reaching the ambitus. Ambulacra straight, depressed above. Apical disk excentric and posterior. 

Mouth opening bilabiate and near the anterior border. Anal opening 

small, high above posterior margin. Fasciole distinct.

Dimensions. Length, 1 inch; .width, % inch; height, | inch.

Description. This form, was originally described by Morton in 1830, 

and later, in 1833, considered by the same writer as the young of 

the species for which the name parastatus was then substituted. In 

presenting a preliminary notice of the present report the writer followed
HEMIASTEE STELLA. 85

*

Morton in this regard, but the examination of a larger amount of material shows that the new species, H. incrassatus, there described is only a 

large form of H. stella, so that it becomes necessary to discard the former 

term and employ both IT. Stella and H. parastatus of Morton. Hemiaster 

Wetlierlyi de Loriol is apparently identical with If. stella Morton.

The test is small, oval, and cordate, and much elevated on the posterior portion of the upper surface. The whole test has a rounded, 

full outline, that is much increased by the absence of the usually deep 

anterior groove, which in H. Stella does not reach the margin (PI. XLVI, 

Fig. la). The posterior border is flatly and nearly vertically truncated.

The ambulacra! areas are depressed in the petaloidal portions which, 

in the autero-lateral pair, are twice as long as in the postero-lateral. 

The poriferous zones are narrow; the pores have transverse slit-like 

openings. The unpaired ambulacrum, is situated in the anterior groove.

The surface of the test is covered with innumerable small tubercles, 

between which is a microscopic granulation. The peripetalous fasciole 

is very distinct, oval, and passes with'a regular curve about the-ends 

of the petaloidal areas. The surface of the test is covered with minute 

tubercles, between which are microscopic granules. The apical disk 

is small, and situated posteriorly to the center of the upper surface of 

the test.

The mouth opening is transversely oval, bilabiate, and placed near 

the anterior margin. The anal opening is small, oval, and situated at 

the upper part of the truncated posterior margin.

Related forms. Hemiaster stella is unique among American Heminsters. The shallow anterior groove, that falls short of the margin, and 

the full elevated test readily distinguish, it from other forms.

Locality and geological horizon. Hemiaster stella is found in the yellow limestone of the middle marl bed (upper Cretaceous) of Timber 

creek, New Jersey.

Collections. U. S. National Museum; Philadelphia Academy of Natural Sciences; Johns Hopkins University.

HEMIASTER UNGULA (Morton). 

Plate XLVI, Figs. 2a-g.

Spatangus ap. Morton, 1830. Am. Jour. Sci., 1st ser., vol. 17, p. 286.

Spatangus unyula Morton, 1833. Am. Jour. Sci., latsor., vol. 23, p. 131, PI. 10, Fig. 6.

Spatangus ungula Mortou, 1834. Synop. Organ. Remains, Cretaceous, p. 78, PI. 10,

Fig. 6.

Micraster ungula Agassiz and Desor, 1847. Cat. rais., p. 141. 

Spatangus unyula Broun, 1848. Index Pal., vol. 1, p. 1161. 

Holaster ungula Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19. 

Hemiaster angula Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test oval, cordiform, elevated; upper surface inflated, elevated posteriorly; lower surface flat; sides sloping; 

anterior sulcus narrow and deep. Ambulacra narrow; poriferous zones 

straight, depressed, petaloidal. Peripetalous fasciole deeply bent
86 MESOZOIC ECHINODERMATA OP THE UNITED STATES. [BUM,. 97.

inward between the anterior and posterior paired ambulacra. Apical 

disk small, compact. Mouth opening transversely oval near anterior 

margin. Anal opening oval, supramarginal.

Dimensions. Length, 1£ inches; width, 1£ inches; height, £ inch.

Description. This species has an oval, cordate test, that is very much 

elevated in the posterior portion. Anteriorly the upper surface slopes 

rapidly, so that the margin is much thinned down, losing the full round 

aspect of the previously described forms. The sharp ridge on the posterior portion of the test is terminated by a nearly vertical truncation 

of the posterior margin. The base is flat, save for the peristomial depression.

The ambulacra! areas are narrow. The poriferous zones are petaloidal, straight, and deeply depressed on the upper surface. The unpaired 

ambulacrum is placed in the anterior sulcus and but slightly exceeds 

the other areas in width. The petals of the antero-lateral pair are twice 

the length of the postero-lateral. The pores of the paired ambulacra 

are elongated and separated (PI. XLVI, Fig. 2e), those of the single ambulacrum small, oval, and approximated (PI. XLVI, Fig. 2/).

The surface of the test is covered with small tubercles, between 

which are numerous minute granules. The peripetalous fasciole is distinct and bent outwards between the anterior and posterior paired 

ambulacra.

The apical disk is small and situated posterior to the center of the 

upper surface. The antero-lateral genital plate is very large and widely 

separates the posterior pair of oculars. The postero-lateral genitals 

have large perforations (PI. XLVI, Fig. 2</).

The mouth opening is transversely oval, bilabiate, with a prominently 

projecting lower lip. The anal opening is large and situated at the 

upper part of the truncated face of the posterior margin.

Related forms. It is separated from Hemiaster parastatus, with which 

it is found, by the narrower anterior groove, more central apical disk, 

less inflated sides, sharper posterior keel, and straight ambulacral 

plates.

Locality and geological horizon. Hemiaster ungula is from the yellow 

limestone of the middle marl bed (upper Cretaceous) of Timber creek, 

New Jersey.

Collections. Philadelphia Academy of Natural Sciences; American 

Museum of Natural History, New York.

HEMIASTER TEXANUS Roemer. 

Plate XLVII, Figs la-i.

Hemiaster texanus Roemer, 1849. Texas, etc., p. 393.

Hemiaster texanus Roemer, 1852. Die Kreidebiklungen von Texas, p. 85. PI. 10, Fig. 4.

Hemiaster americanus Giebel, 1853. Jahresber. cl. Naturw. Ver. in Halle, p. 372,373.

Hemiaster texanus Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 19.

Hemiaster texanus Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 3:

Hemiaster texanus Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 77.
CIABK.] HEMIASTER TEXANUS. 87

Determinitive characters. Test oval, cordate, declining anteriorly, 

elevated slightly posteriorly; anterior sulcus broad and deep, producing groove in margin. Ambulacra broadly depressed on upper surface; 

antero-lateral pair bent backward in upper part; unpaired ambulacrum very broad. Apical disk compact, the four genitals distinctly 

' perforated. Mouth opening large, transversely oval, bilabiate. Anal 

opening large, oval, at center of truncated surface of posterior margin.

Dimensions. Length, 1^ to 2 inches; width, 1£ to If inches; height, 

£ to 1 inch.

Description. This important species is broadly cordate and slightly 

depressed on the upper surface; base Hat. Posterior to the apex there 

is a sharp ridge that declines gradnally toward the obliquely truncated 

margin,. Anteriorly the upper surface declines toward the anterior 

border.

The atnbulacral areas are broad, very unequal, and depressed in the 

petaloidal portions. The poriferous zones are broad, the pores of the 

paired ambulacra elongated (PI. XLVH, Fig. le), those of the single ambulacrum round and approximated (PI. XLVII, Fig. I/). The petals of 

the antero-lateral pair are bent backward in their upper part and are 

nearly twice the width of the postero-lateral pair. The single ambulacrum, is very broad, the poriferous zones widely separated.

The surface of the test is covered with small tubercles that are perforated and for the most part crenulated (PI. XLVTI, Fig. Ik, li). A 

microscopic granulation fills the intertubercular space.

The apical disk is small and compact and situated near the center. 

The four genital plates are distinctly perforated; the antero-lateral is 

larger than the others and serves as the madreporite. The live oculars 

are wedged between the genitals and are deeply cut by the upper portions of the anibulacra (PI. XLVIT, Fig. 1g).

The mouth opening is la.rge, transversely oval, and bilabiate. The 

anal opening is large, oval, and situated in the center of the truncated 

surface of the posterior margin (PI. XLVII, Fig. Id).

Related forms. Under the name of Hemiaster americamis, Giebel published the description of a new species of Hemiaster, in 1853, that he 

states can be with difficulty distinguished from If. texanus. It is considered identical in the present report. The differences seem hardly to 

warrant the establishment of a new species. Periaster australis, described by Gabb, from Peru, so far as the figures and description show, 

must be a Hemiaster, and to all appearances is closely allied if not 

identical Avith H. texanus.

Locality and geological horizon. Hemiaster texanus is from the upper 

division of the Cretaceous of Texas. It is characteristic of the Austin 

chalk.

Collections. U. S. National Museum; Prof. Eobt. T. Hill.
88 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

. HEMIASTER HUMPHREYS ANUS Meek and Hayden. 

Plate XLVIII, Figs.

Hemiaster (?) Humphreysanus Meek and Hayden, 1857. Philadelphia Acad. Nat.

Sci. Proc., vol. 9, pp. 147, 148.

Hemiaster (?) Humplireysanus Gabb, 1859. Cat. Invert. Fossils Cretaceous, p. 19. 

Hemiaster (?) Humphreyaanus Meek, 1864. Smith. Misc. Coll., vol. 7 (177), p. 3. 

Hemiaster Humphreysanns Meek. U. S. Geol. Surv. of the Territories, vol. 9, pp. 5,

6, PI. 10, Figs. la-g. 

Hemiaster Humphreysanus Clark, 1891. Johns Hopkins University Circulars, No.

87, p. 77. . .

Determinative characters. Test oval, cordate; upper surface high, 

flat, with broad, vertical truncation on posterior margin, and longanterior groove; base flat; sides rounded. Ambulacra in deep furrows 

that reach to the edge of the elevated sides. Apical disk large and 

compact, posteriorly situated. Mouth opening small, transversely oval, 

and bilabiate. Anal opening oval, situated high on posterior margin.

Dimensions. Length, 1J inches; width, 1£ inches; height, finch.

Description. The absence of distinct fascicles on the type specimens 

of this species caused Meek and Hayden to place it doubtfully in the 

genus Hemiaster, to which beyond doubt it belongs. The test is full, the 

sides rounded, and the high upper surface distinctly flattened. The 

base is also flat, with the exception of the peristomial depression. The 

situation of the apex so far posterior to the center of the upper surface 

produces a long anterior sulcus, that grooves the anterior margin. A 

high, vertically truncated surface terminates the posterior margin.

The ambulacral areas are broad, very unequal, and deeply depressed 

on the upper surface. The petals of the postero-lateral pair are very 

short, those of the antero-lateral very long, the latter quite three 

times the length of the former. The unpaired ambulacrum occupies 

the long anterior sulcus. The antero-lateral pair are bent backward 

in the upper part and forward in the lower. The poriferous zones are 

broad, the pores distinct and oval (PI. XLVIII, Figs, le, If). Since much 

of the surface of the test has suffered removal the character of the 

tubercles and granules can not be fully determined.

The apical disk, which has been largely destroyed, was large, compact, and situated far posterior to the center of the upper surface.

The mouth opening is small and situated near the anterior margin. 

The anal opening is oval and situated on the vertically truncated surface of the posterior margin (PI. XLVIII, Fig. 1$).

Eelated forms. Hemiaster Humphreysanus is a unique form, that is 

not closely related to any species of Hemiaster hitherto described.

Locality and geological horizon. This species is from the Fort Pierre 

formation (upper Cretaceous) of Meek and Hayden and was found 150 

miles from the mouth of the Yellowstone river in Montana.

Collection. U. S. National Museum.
OLABK.] HEMIASTER DALLI. 89

HEMIASTER DALLI Clark. 

Plate XLvin, Figs. 2a-e.

JEfemiaster Dalli Clark, 1891. Johns Hopkins University Circulars, No. 87, pp. 77.

Determinative characters. Test cordate, subhexagonal, depressed; 

upper surface with sliarp ridges between tlie ambulacralfurrows; base 

flat; sides rapidly declining; anterior margin deeply grooved. Ambulacra unequal, very deeply depressed on petaloidal portions; anterolateral pair much bent in upper part. Mouth opening transversely 

oval, near anterior margin. Anal opening oval, situated on vertically 

truncated surface of posterior margin.

Dimensions. Length, If inches; width, 1-f inches; height, f inch.

Description. This species is much depressed, with distinct marginal 

angles that give it a subhexagonal outline. Prominent ridges cross 

the upper surface between the ambulacra! furrows. The anterior sulcus 

cuts deeply into the test and grooves the anterior margin. The sides 

decline rapidly to the flattened base. The low posterior surface has a 

nearly vertical truncation of small area.

The ambulacral areas are very deeply depressed on the upper surface, a feature much more pronounced than in any other American 

species. The antero-lateral pair are bent backward in their upper 

part, and have long, deep furrows. The postero-lateral pair are about 

one-half the length of the anterior pair. The single ambulacrum is 

situated in the broad, deep, anterior sulcus. The poriferous zones in 

the paired ambulacrum are broad, the pores oval, those of each pair 

united by a shallow furrow (PI. XLVIII, Fig. 2e). In the unpaired ambulacrum the poriferous zones are narrow, the pores small and approximated.

The surface is covered with small tubercles with sunken areolas 

that increase in size toward the base, where they are large, with distinctly perforated mamelons and crenulated bosses. A fine microscopic 

granulation fills the interspaces.

The apical disk is sunken, small, and posterior to the center of the 

upper surface.

The mouth opening is transversely oval and close to the anterior" 

margin.

The anal opening is oval and situated on the truncated surface of the 

posterior border (PI. XLVIII, Fig. 2d).

Related forms. The very deep ambulacra,! furrows and angular outline readily separate Hemiaster Dalli from any other American species. 

It is not closely allied to any European form.

Locality and geological horizon. This form is from the Washita 

formation of the Comanche series (lower Cretaceous) of Bexar county, 

Texas.

Collection. U. S. National Museum.
90 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

HEMIASTER OALIFOENICUS Clark. 

Plate XLIX, Figs. la-c.

ffemiaster caUfornicus Clark; 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Determinative characters. Test small, subquadrate, depressed; upper surface flat, with shallow anterior sulcus, sloping sides, and low 

truncated posterior margin; lower surface flat. Ambulacra depressed, 

in shallow furrows. Apical disk small, posterior to center. Mouth 

opening transversely oval near anterior margin. Anal opening situated on the low truncated surface of the posterior margin.

Dimensions. Length, 1 inch; width, 1 inch; height, £ inch.

Description. This form, the single representative of the Echinodermata thus far obtained from the Cretaceous deposits of California, has 

the details of its structure poorly preserved in the specimens examined, 

although it belongs, beyond much doubt, to the genus Hetniaster. 

The test is small, much depressed, and subquadrate in arnbital outline. 

It is broader anteriorly, with a feeble groove in the center of the anterior margin. The., posterior portion of the test is but slightly more 

elevated than the anterior, and the truncated margin is low and narrow. 

The base is flat, with the exception of the peristomial depression.

The ambulacral areas are but slightly depressed in the petaloidal 

portions. The poriferous zones are broad, and the oval pores are united 

by shallow furrows (PI. XLIX, Fig. la).

The apical disk is small and situated slightly forward of the center.

The mouth opening is transversely oval and situated near the anterior margin (PI. XLIX, Fig. 16). The anal opening is small, oval, and 

situated on the low, truncated surface of the posterior border.

.. Related forms. On account of its shallow ambulacral furrows, Semiaster caUfornicus may be compared to H. Humphrey sanus, but is readily 

separated from it by means of its more central apical disk and its 

depressed form. It is a very unique species.

Locality and geological horizon. H. caUfornicus is from Eedding, 

Shasta county, California, in deposits that have been referred to the 

Ohico group (upper Cretaceous).

Collection. U. S. National Museum.

HEMIASTEB, CALVINI Clark. 

Plate XLIX, Figs. 2a-i.

Determinative characters. Test oval, cordate, inflated; upper surface elevated; lower surface flat; posterior margin obliquely truncated. 

Ambulacra moderately depressed on the upper surface. Mouth opening transversely oval. Anal opening oval, high on truncated posterior 

border.

Dimensions. Length, 1£ inches; width, 1£ inches; height, £ inch.

Description. This species has an elevated test that is oval, cordater
CLARK.] HEMIASTER CALVINI LINTHTA TUMIDULA. 91

and broadly truncated on the posterior margin. The anterior sulcus is 

shallow, and produces but a feeble groove on the anterior margin. The 

base is flat.

The ambulacral areas are narrow. The poriferous zones are broad 5 

the petals moderately depressed and of good length; the pores in the 

petaloidal portions of the -paired ambulacra elongated, slit-like (PI. 

XLTX, Fig. 2e), those of the unpaired ambulacrum small and approximated (PI. XLIX, Fig. 2#). Beyond the petals the pores are very small, 

and occupy the lower outside corner of each plate (PI. XLIX, Fig. 2/).

The surface of the plates is covered with small perforated tubercles, 

rather Avidely scattered, between which a microscopic granulation intervenes. The peripetalous fascicle is indistinct.

The apical disk is small, compact, and nearly central (PI. XLIX, 

Fig. 2t).

The mouth opening is small, transversely oval, and situated at a distance from the margin.

The anal opening is oval and situated high on the truncated surface 

of the posterior margin.

Related forms. Hemiaster Calvini is most closely related to H. texanus, from, which', however, it is separated by its more elevated form 

and small, narrow, anterior sulcus. The apical disk is also more excentric.

Locality and geological horizon. Hemiaster Calvini is from the Shoal 

creek limestone at the top of the Coinanche series (lower Cretaceous) of 

Texas. It is found in Travis county.

Collections, U. S. National Museum; University of Iowa.

LINTHIA Merian.

LINTHIA TUMIDULA Clark.

Plate L, Figs. la-i.

LintMa tumidula Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 77.

Determinative characters. Test oval, cordiforni, elevated; apex central; posterior border obliquely truncated, anterior portion grooved by 

narrow sulcus; sides sloping. Ambulacral farrows long, straight, depressed; poriferous zones broad, pores oval. Apical disk small, nearly 

central. Anal opening on truncated posterior border. Peripetalous 

and lateral fascicles distinct.

Dimensions. Length, 2£ inches; width, 2 inches; height, 1£ inches.

Description. This large form has an elevated test, with flattened, 

sloping sides, oval outline, and a narrow, moderately depressed anterior 

sulcus that grooves the anterior margin. The base is flat, except for 

the peristomial depression.

The ambnlacral areas are narrow and furrow for a long distance the 

upper surface of the test to a moderate depth. The poriferous zones
92 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

are broad and straight. The pores are large and oval, and those of 

each pair connected by a shallow furrow (PI. L, Fig, If). The anterolateral petals reach far down the sloping sides and are about one aud 

one-half times as long as the postero-lateral pair.

The surface of the test is covered with minute, perforated tubercles 

that are much larger on the base than on the upper surface. A microscopic granulation fills the space between the tubercles (PI. L, Fig. 1*). 

Both the peripetalous and lateral fascicles can be readily traced.

The apical disk is small, nearly central, and slightly depressed (PI. 

L, Fig. Ig).

The mouth opening is transversely oval and situated near theanterior margin. The anal opening is small, oval, and situated but a 

short distance above the posterior margin (PI. L, Fig. Id).

Related forms. L. tumidula is the only representative of the genus 

from American deposits. It is not closely allied to any species described elsewhere.

Locality and geological horizon. LintMa tumidula is from the yellow 

limestone of the middle marl bed (upper Cretaceous), of Timber creek, 

New Jersey.

Collections. American Museum of Natural History, New York; BostonSociety of Natural History.

DOUBTFUL AND UNRECOGNIZED SPECIES.

With few exceptions the writer has had an opportunity of examining 

the type forms of previous writers upon the Mesozoic Echinodermata of 

the United States, and as a result Cassidulus abruptus Conrad, Arbacia 

sp. Eoemer, and Diaderna sp. Eoemer are the only species that can not 

be identified. Three other species two from lack of generic characters (Pygurus (?) geometricus (Morton) and Cidaris nahalalcensis de 

Loriol), the third (Discoidea occidentale Gabb) because of probable 

foreign origin are not included, although the synonymy of each is 

given for purposes of reference. A single specific name (Holectypus 

simplex Eoemer) has found its way into the literature from its use in 

Gabb's Catalogue, although probably mentioned by mistake.

CASSIDULUS ABRUPTUS Conrad.

Cassidulus abruptns Conrad, 1860. Philadelphia Acad. Nat. Sci. Jour., new ser., vol. 4,

p. 291. 

Cassidulus abruptus Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

This species, originally described by Conrad in 1860, but not figured, 

is from Tippah county, Mississippi. It has not been- recognized in 

material examined by the writer, so that its relations to the other forms 

described are not known.

PYGURUS (?) GEOMETRICUS (Morton).

Clypeaster sp. Morton, 1830. Philadelphia Acad. Sci. Jour., 1st ser., vol. 6, p. 202. 

Clypeaster geometricus Morton, 1833. Ani. Jour. Sci., 1st ser., vol. 24, p. 131, PI. 10, 

Fig. 9o
CLABK.] CIDARIS DISCOIDEA HOLECTYPUS. 93

Clypeaster yeometricits Morton, 1834. Synop. Organ. Remains, Cretaceous, p. 76, PI. 10,

Fig. 10.

Pyguriis geometricus Agassiz and Desor, 1847. Cat. rais., p. 141. 

Pygurus geomvtriciis d'Orbigny, 1847. Prodrome, vol. 2, p. 270. 

Clypeaster geometricus Bronn, 1848. Index Pal. vol. I, p. 312. 

Pyguriis geomvtricus d'Orbiguy, 1853-'60. Pale"ont. frangaise, vol. 6, p. 313, PI. 920,

Fig. 4.

Pygiirus geometricus Desor, 1858. Synop. des Echinides fossiles, p. 313. 

Clypeaster geometricus Gabb, 1859. Cat. Invert. Fossils, Cretaceous, p. 18. 

Pi/gurus (f) geometricns Clark, 1891. Johns Hopkius University Circulars, No. 87, p. 77.

The type of this species was examined by the writer, but its state of 

preservation (.that of a poor cast) is such that its generic relations cannot be with certainty determined. Until further .material is obtained 

it seems best to defer its recognition.

Although originally described by Morton as a Clypeaster, it has been 

referred to the genus Pygurus by Agassiz, d'Orbigny, and Desor. The 

single specimen was obtained from, the lower marl bed (upper Cretaceous) of the Delaware and Chesapeake canal.

CIDARIS NAHALAKENSIS de Loriol.

Cidarisnahalakensis do Loriol, 1887. Recueil Zoologique suisse, tome 4, pp. 388,389, 

PL 17, Figs. 3-4.

The present species is based by P. de Loriol upon fragment of spines 

obtained from the Rotten limestone of the upper Cretaceous of Nahalak, 

Kemper county, Mississippi. The acceptance of the species is reserved 

until fuller material has been obtained. Similar spines have been 

recognized by the writer from other localities, but whether they represent an independent species or one hitherto described is not yet 

clear.

DISCOIDEA OCOIDENTALE Gabb.

Discoidca occidentale Gabb, 1860. Philadelphia Acad. Nat. Sci. Jour., new ser., vol. 4.

p. 398, PI. 68, Figs. 42-44.

Discoidea oceidentale Gabb, 1876. Philadelphia Acad. Nat. Sci. Proc., vol. 28, p. 323. 

.Diacoidca occidental Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77,

When first described in 1860 Gabb referred this form to the Cretaceous of Oregon, but later, in 1876, thought he might have been mistaken 

in the locality and mentioned Peru as its probable origin. In view of 

this doubt it is omitted from the list of species.

¥ HOLECTYPUS SIMPLEX Shumard.

? Holectypus simplex Shuniard (description unknown).

Holectypus simplex Meek, 1864. Smith Misc. Coll., vol. 7 (177), p. 2.

? Holectypus simplex Clark, 1891. Johns Hopkins University Circulars, No. 87, p. 77.

Meek includes Holectypus simplex Shumard among his list of American 

Cretaceous Echinodermata and gives Texas as the locality. As a careful 

search of the literature and extended correspondence with those familiar 

with Shuniard's writings fail to elicit any information upon this point, 

the writer is of the opinion that the reference to this species by Meek 

is a mistake. No such species was probably ever described.
94. HESOZOIC ECHINODERMATA OF THE UNITED STATES. [BOLL. 97. 

GEOLOGICAL DISTRIBUTION.

«

CKINOIDEA:

TJlNTACRINIDjE 

APIOCRWIDJE 

PENTACRINIM: 

ASTEKOlDEA:

OPHIUBlDjE 

STELLEBID.*: 

ECHINOIDEA:

EUECHINOIDEA * 

REQULARES 

ClDARIDAE 

SALENIDAE 

DIADEHATID^; 

ECHiNiD.i 

IBEEGDLARES 

ECHLNOCONID.E 

CASSIDULID^E 

HOLASTEBIDAE 

SPATANGIDAE 

Trias.

V / 1 \

Jura.

X 

X

X

X

X

X 

X

X

Lower 

Cretaceous.

X

X 

X

X

*

X

X

X 

X

X

X

X

X

X

X

Upper Cretaceous.

X 

X

X 

X

X

X 

X

X 

X

X

X 

X 

X

X

X

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X 

X

X 

X

X 

X 

X 

X 

X

X

X
CLARK.] CATALOGUE OF SPECIFIC NAMES. 95

CATALOGUE OF SPECIFIC NAMES EMPLOYED BY WRITERS UPON 

THE MESOZOIC ECHINODERMATA OF THE UNITED STATES.

Taga

Ananchytes sp. Morton, 1830=Cardiaster cinctus (Morton) .... 75

cinctus Morton, 1830=Cardiaster ciuctus (Morton......... 75

cinctus Morton, 1834=Cardiaster cinctus (Morton) ........ 75

cinctus Gabb, 1859=Cardiaster cinctus (Morton).......... 75

cruciferus Morton, 1830=Trematopygus crucifer (Morton).. 63

fimbriatus Morton, 1830=Cardiaster cinctus (Morton) ..... 75

fimbriatus Morton, 1834=Cardiaster ciuctus (Morton) ..... 75

fimbriatus Bronu, 1848=0ardiaster cinctus (Morton) ...... 75

fimbriatus Gabb, 1859=Cardiaster cinctus (Morton)....... 75

ovalis Clark ......°....................................... 74

Arbacia sp. Eoenier, 1849=unrecognized .......... .......... 92

Asterias ? dnbiuinWliitfield, 1877............................ 31

? dubium Clark=Asterias dnbiuni Wliitfield.............. 31

Botriopygus alabaruensis Clark ............................ J. 60

Bourgueticrinus alabamensis de Loriol, 1882 .................. 25

alabameiisis Clark=Bourgueticrinus alabamensis de Loriol 25

Cardiaster cinctus (Mortou).................................. 75

cinctus d'Orbigny, 1853-'60=Cardiaster cinctus (Morton) .. 75

cinctus (fimbriatus) Desor, 1858=Cardiaster cinctus (Morton) 75

cinctus Clark=Cardiaster cinctns (Morton) ............... 75

fimbriatus d'Orbigny, 1853-'60=Cardiaster ciuctus (Morton) 75

Cassidulus abruptus Conrad, 1860............................ 92

sequoreus Morton, 1834.................................. 68

aequoreus Desmoulins, 1837=Cassidulus requoreus Morton . 68

aequoreus Agassiz, 1847=Cassidulus aequoreus Morton..... 68

aequoreus d'Orbigny, 1847=Cassidulus aequoreus Morton... 68

aequoreus Bronn, 1848=Cassidulus aequoreus Morton...... 68

aequoreus d'Orbigny, 1853-'60=Cassidulus aequoreus Morton 68

aequoreus Desor, 1858=Cassidulus aequoreus Morton ...... 68

aequoreus Gabb, 1859=Cassidulus aequoreus Morton....... 68

aequorens Meek, 1864=Cassidulus aequoreus Morton ....... 68

aequoreus Conrad, 1868=Cassidulus tuquoreus Morton ..... 68

aequoreus Clark=Cassidulus aequoreus Morton ............ 68

norealis (Morton) ....................................... 66

florealis Meek, 1864=Cassidulus florealis (Morton). ....... 66

florealis Clark=Cassidulus florealis (Morton) ............. 66

niicrococcus Gabb, 1860 ................................. 69

micrococcus Clark=Cassidulus micrococcus Gabb ......... 69

porrectus Clark, 1891 ................................... 72

Stantoni Clark, 1891 .................................... 73

subconicus Clark, 1891 ........... '. ..................... 71

Biibquadratus Conrad, 1860 .............................. 70

subquadratus Clark=Cassidulus subquadratus Conrad.... 70
96 MESOZOIC ECHINODERMATA OF TPJE UNITED STATES. [BULL.97.

	i'ago.

Catopygus oviformis Conrad, 1847............................ 64

oviformis Clark=Gatopygus oviformis Conrad ............ 64

pusillus Clark .......................................... 65

Cidaris sp. Morton, 1829=Cidaris splendens Morton........... 33

armiger Gabb, 1859=Cidaris splendens Morton ........... 33

armiger Clark=Cidaris splendens Morton ................ 33

californicus Clark....................................... 36

c]avigeraCredner,1870=Pseudodiadema diatretum (Morton) 46

diatretum Morton, 1833=Pseudodradema diatretum (Morton) 46

diatrettim Bronn, 1848=Pseudodiadema diatretum (Morton) 46

diatretum Gabb, 1859=Pseudodiadema diatretum (Morton) 46

diatretum Gie'bel, 1853=Salenia texana Cre.dner .......... 40

hemigrauosus Shumard, 1860=Leiocidaris hemigranosus

(Shumard)............................................. 38

hemigranosus Meek, 1864=Leiocidaris hemigranosus (Shumard) ................................................. 38

hemigranosus White, 1883=Leiocidaris hemigranosus (Shumard) .................................................. 38

nahalakensis de Loriol, 1887 ............................. 93

nahalakensis Clark=Cidaris nahalakensis de Loriol........ 93

sceptrifera Credner, 1870=Pseudodiadema diatretum Morton .................................................. 46

splendens Morton....................................... 33

splendens Clark=Cidaris splendens Morton .............. 33

splendeus Gabb, 1859=Cidaris splendeus Morton ......... 33

taylorensis Clark ....................................... 35

texanus Clark, 1891..................................... 36

Walcotti Clark, 1891.................................... 37

Cidarites armiger Morton, 1842=Cidaris splendens Morton..... 33

diatretum Morton, 1834=Pseudodiadema diatretum (Mortou) 46

splendens Morton, 1841=Cidaris splendens Morton........ 33

Clypeaster sp. Morton, 1829=Cassidulus florealis (Morton)..... 66

geoinetricus Morton, 1833=Pygurus (?) geometricus (Morton) 92

geometricus Morton, 1834=Pygurus (H) geometricus (Morton) 92

geometricus Bronn, 1848=Pygxirus (?) geometricus (Morton) 92

geometricus Gabb, 1859=Pygurus (?) geometricus (Morton) 92

florealis Morton, 1833=Cassidulus florealis (Morton)....... 66

florealis Morton, 1834=Cassidulus florealis (Morton)....... 66

florealis Bronn, 1848=Cassidulus florealis (Morton) ........ 66

florealis Gabb, 1859=Cassidulus florealis (Morton) ........ 66

Coptosoma Mortoui (de Loriol) ............................... 51

speciosum Clark, 1891................................... 52

Cyphosoina Mortoni de Loriol, 1887=Coptosoma Mortoni (de

Loriol) .... .... ...................................... - 51

speciosum Clark, 1891=Coptosoma speciosum Clark....... 62
CLAHK.J CATALOGUE OF SPECIFIC NAMES. 97

Page.

Cypbosoma texanum Boemer, 1852=Diplopodia texanum (Boemer) .................................................. 48

texamiin Conrad, 1857=Diplopodia texanum (Boemer)..... 48

texanum Gabb, 1859=Dipiopodia texanum (Boeraer)....... 48

texanum Gabb, 1869=Diplopodia texanum (Boerner)....... 48

Diadema sp. Boemer, 1852=unrecognized..................... 92

diatretuui Agassiz and Desor, 1847=Pseudodiadenia diatretum (Mortou) ....................................... 46

texanum Boemer, 1849=Diplopodia texanum (Boemer)..... 48

texanum Boemer, 1852=Pseudodiadema texanum (Boemer). 47

texanum Gabb, 1859=Pseudodiadema texanum (Boemer).. 47

Diplopodia texanum (Boemer) ................................ 48

texanum Clark=Diplopodia texanum (Boemer)............ 48

Hilli Clark, 1891........................................ 50

UDiscoidea occidentale Gabb, 1860 ........................... 93

occideutale Gabb, 1876=Discoidea occideutale Gabb ...... 93

occidentale Clark, 1876=Discoidea occidentale Gabb ...... 93

Echinobrissus cruciferus d'Orbigny, 1854=Trematopygus crucifer (Morton).......................................... 63

expansus Clark, 1891.................................... 61

texanus Clark, 1891..................................... 62

Echinus sp. Morton, 1830=Cidaris splendens Mortou .......... 33

Enallaster obliquatus Clark.................................. 79

texanus (Boemer) ....................................... 78

texanus Desor, 1858=Enallaster texanus (Boemer) ........ 78

texauus Clark=Enallaster texanus (Boemer).............. 78

texasus d'Orbigny, 1853-'60=Enallaster texanus (Boemer). 78

Encrinites sp. Shiel, 1855=Pentacrinus asteriscus Meek and

Hayden.............................................. 26

Epiaster elegans (Shumard).................................. 80

elegans Clark=Epiaster elegans (Shumard)............... 80

Whitei Clark, 1891................................. .... 82

Faujasia florealis d'Orbigny, 1853-'60=Cassidulus florealis (Morton) .................................................. 66

florealis Desor, 1858=Cassidulus florealis (Morton) ........ 66

Goniaster mammillata Gabb, 1876 ............................ 32

mammillata Clark=Goniaster mammillata Gabb .......... 32

Goniopygus Zitteli Clark, 1891............................... 53

Hemiaster americanus Giebel, 1853=Hemiaster texanus Boemer. 86

californicus Clark, 1891.................................. 90

Calvini Clark........................................... 89

Dalli Cla,rk, 1891........................................ 80

elegans Shumard, 1853=Epiaster elegans (Shumard)...... 88

Humphreysanus Meek & Hayden, 1857 ................... 88

Humphreysanus Gabb,, 1859=Hemiaster Humphreysanus

Meek & Hayden ...'. i..'........................... fc ... 88

Bull. 97 7
98 MESOZOTC ECHINODERMATA OF THE UNITED STATES. [BULL.07.

Pago.

Heiniaster *? Humphrey sanus Meek, 1864=HemiasterHumphreysanus Meek & Hayden ................................ 88

Humphreysanus Meek, 1876=Heiniaster Humphreysanus

Meek & Hayden ............................ ......... 88

Humphreysanus Clark=Heiniaster Humplireysauus Meek &

Hayden ............................................... 88

incrassatus Clark, 1891=Heiniaster stella (Morton)........ 84

parastatus (Morton)..................................... 83

parastatus Desor, 1847=Heiniaster parastatus (Morton) ... 83 

parastatus d'Orbiguy, 1847=Heiniaster parastatus (Morton) 83 

parastatus d'Orbigny, 1S53-'60=Heiniaster parastatus (Morton).. ................................................ 83

parastatus Desor, 1858=Hemiaster parastatus (Morton).... 83

parastatus Gabb, 1859=Hemiaster parastatus (Morton).... 83

parastatus Meek, 1864=Hemiaster,parastatus (Morton).... 83

parastatus, Olark=Hernia ster parastatus (Morton) ........ 83

stella (Morton) ......................................... 84

stella Agassiz & Desor, 1847=Heiniaster stella (Morton)... 84

stella Desor, J 858=Heiniaster stella (Morton) .............. 84

stella Gabb, 1859=Heiniaster stella (Mortou) ............. 84

!stella Meek, 1864=Heiniaster stella (Morton)............. 84

stella Clark=Herniaster stella (Morton) .................. 84

texauus Eoemer, 1849 ................................... 86

texanus Eoemer, 1852=Hemia ster texanus Boomer........ 86

texanus Gabb, 1859=Heiniaster texauus Eoemer.......... 86

texauus Meek, 1864=Heiniaster texanus Eoemer .......... 86

texanus Clark=Hemiaster texanus Eoemer ............... 86

Wetlierbyi de Loriol, 1887=Heiniaster stella (Morton)...... 84

nngala, (Morton)........................................ 85

ungiila Clark=Heiniaster ungula (Morton)................ 85

Hemicidaris intumescens Clark .............................. 44

Holaster cinctus Agassiz, 1840=Cardiaster cinctus (Morton) ... 75 

einctus Agassiz and Desor, 1847=Cardia ster cinctus (Morton) .................................................. 75

cinctus d'Orbigny, 1847=0ardiaster cinctus (Morton)......" 75

ciiKjtus Broun, 1848=Cardiaster cinctus (Morton) ......... 75

cinctus Credner, 1870=Cardiaster cinctus (Morton)........ 75

cinctus Clark, 1891=Cardiaster cinctns (Mortou).......... 75

comanchesi Marcou, 1858=Holaster simplex Shumard...... 76

coinanchesi Desor, 1858=Holaster simplex Shumard....... 76

conianchevsi Gabb, 1859=Holaster simplex'Shumard........ 76

comanchesi Meek, 3*864=Holaster simplex Shumard........ 76

elegans Conrad, 1857 (figure only) =Epiaster Whitei Clark.. 82 

fimbriatus Agassiz and Desor, 1847=Cardiaster cinctus

(Morton) ............,,.,,,.,..,.,..,................,, 75
CLARK.] CATALOGUE OP SPECIFIC NAMES. 99

Pago.

Holaster fimbriatus d'Orbigny, 1847=Cardiaster cinctus (Morton).................................................. 75

parastatus Gabb, 1859=Hemiaster parastatus (Morton).... 83

simplex Shumard, 1853 .................................. 70

simplex Desor, 1858=Holaster simplex Shumard .......... 70

simplex G-abb, 1859=Holaster simplex Shumard........... 70

simplex Meek, 1864=Holaster simplex Shumard........... 70

simplex Clark=Holaster simplex Shumard ............... 70

ungula Gabb, 1859=Hemiaster ungula (Morton)........... 85

Holectypus planatus Eoeiner, 1849 ........................... 58

planatus Eoemer, 1852=Holectypus planatus Eoemer...... 58

planatus Shumard, 1852=Holectypus planatus Roomer .... 58

planatus Giebel, 1853=Holectypus planatus Eoemer........ 58

plauatus Conrad, 1857=Holectypus planatus Eoemer...... 58

planatus Desor, 1858=Holectypus planatus Eoemer ....... 58

plauatus Gabb, 1859=Holectypus planatus Eoemer........ 58

planatus Meek, 1864=Holectypus planatus Eoemer........ 58

planatus Clark=Holectypus planatus Eoemer............. 58

planus Giebel, 1853=Holectypus planatus Eoemer ........ 58

simplex Meek, 1864 (probably, accredited to Shumard by

mistake) ............................................. 93

Leiocidaris hemigranosus (Shumard) ......................... 38

heinigranosus 01ark=Leiocidaris hemigranosus (Shumard). 38

Linthia tumidula Clark...................................... 91

Macraster texanus Eoemer=Epiaster elegans (Shumard)........ 80

Micraster ungula .Agassiz and Desor, 1847=Hemiaster uugula

(Morton) ............................................. 85

Nucleolites crucifcr Morton, 1833=Trematopygus crucifer (Morton) ...........................................'....... 63

crucifer Morton, 1834=Trematopygus crucifer (Morton).... 03

crucifer Bronn, 1848=Trematopygus crucifer (Morton) .... 03

crucifer d'Orbigny, 1853-'60=Trematopygus crucifer (Morton) .................................................. 63

crucifer Desor, 1858=Trematopygus crucifer (Morton)..... 63

crucifer Gabb, 1859=Trematopygus crucifer (Morton)...... 63

crucifer Meek, 1864=Trematopygus crucifer (Morton)...... 63

crucifer Cook, 1868=Trematopygus crucifer (Morton)...... 63

crucifer Conrad, 1868=Trematopygus crucifer (Morton).... 03

cruciferus Agassiz, 1840=Trematopygus crucifer (Morton).. 63

cruciferus d'Orbigny, 1847=Trematopygus crucifer (Morton). 63 

cruciferus Agassiz and Desor, 1847=Trematopygus crucifer

(Morton) ............................................. 63

cruciferus Credner, 1870=Trematopygus c.rucifer (Morton). 63

Ophioderma (?) bridgererisis Meek, 1873=Ophioglypha bridgerensis (Meek).......................................... 29

bridgerensis White, lS83=Ophioglypha bridgerensis (Meek) 29
100 MESOZOIC ECHINODERMATA OF THE UNITED STATES. [BULL. 97.

Page.

Ophioglypha bridgerensis (Meek) ............................ 29

bridgerensis Clark=Ophioglypha bridgerensis (Meek)..... 29

texana Clark ........................................... 30

Pedinopsis Pondi Clark ..................................... 57

Pentacrinus asteriscus Meek & Hayden, 1858 ................. 26

asteriscus Meek & Hayden, 1860=Pentacrinus asteriscus 

Meek & Hayden ...................................... 26

asteriscus Meek, 1864=Pentacrinus asteriscus Meek & Hayden .................................................. 26

asteriscus Clark=Pentacrinus asteriscus Meek & Hayden.. 26 

Bryani Gabb, 1876 ...................................... 28

Bryani Clark=Pentacrinus Bryani Gabb ................. 28

Whitei Clark ....................... 1................... 27

Pentacrinites asteriscus Meek & Hayden, 1865=Pentacrinus asteriscus Meek & Hayden ....... t...................... 26

(?) asteriscus Whitfield,1880=Pentacrinus asteriscus Meek & 

Hayden........................................;..... 26

asteriscus White, 1875=Pentacrinus Whitei Clark......... 27

(?) asteriscus (t) Hall & Whitfield, 1877=Pentacrinus Whitei 

Clark................................................ 27

(?) asteriscus Whitfield, 1880=Pentacrinus Whitei Clark .. 27 

Phyrnosoma texanum Desor, 1858=Diplopodia texanum (Boeiner) 48 

Psammechinus cingulatus Clark, 1891......................... 55

Pseudodiadema diatretum (Morion) .......................... 46

diatretum Desor, 1858== Pseudodiadema diatretum (Morton). 46 

diatretum Cotteau,1862-'67=Pseudodiadema diatretum(Mor- 

. ton).................................................. 46

diatretum Meek, 1864=Pseudodiadema diatretum (Morton). 46 

diatretum Conrad, 1868=Pseudodiadema diatretum (Morton) 46 

diatretum Clark=Pseudodiadema diatretum Morton....... 46

Emersoni Clark......................................... 45

Hilli Clark, 1891=Diplo,podia Hilli Clark ................. 50

Eoemeri Clark, 1891=Pseudodiadema texanum (Eoemer) .. 47 

texanum (Boemer) ...................................... 47

texanum Desor, 1858=Pseudodiadema texanum (Koemer).. 47 

texanum Meek, 1864=Pseudodiadema texanum (Boemer) .. 47 

texanum Clark, 1891=Diplopodia texanum (Boemer) ...... 48

Pygorhynchus crucifer Bavenel, 1850=Trematopygus crucifer

(Morton)............................................. 63

Pygurus florealis Agassiz, 1847=Cassidulus florealis (Morton).. 66 

florealis Conrad, 1868=Cassidulus florealis (Morton)....... 66

( 1) geometricus (Morton)............................... 92

geometricus Agassiz & Desor, 1847=Pygurus (?) geometricus (Morton) ......................................... 92

geometricus d'Orbigny, 1847=Pygurus (?) geometricus 

(Morton) ....'........ .,,,, ,,,,,.,,,,..,.,,.,,,,,,,,.. 92
CATALOGUE OF SPECIFIC NAMES. 101

	Page.

Pygurus geometrieus d'Orbigny, 1853-'60=Pygurus (?) geometricus (Morton)........................................ 92

geometrieus Desor, 1858=Pygurus (?) geometricus (Morton) 92

(1) geometrieus Clark=Pygurus (?) geometrieus (Morton). 92

Pyrina Parryi Hall, 1857 ..................................... 59

Parryi Gabb, 1859 caPyrina Parryi Hall................... 59

Parryi Meek, 1864=Pyrina Parryi Hall .I.....**......*... 59

Parryi Clark=Pyrina Parryi Hall. ....................... 59

Balenia bellula Clark, 1891 ........ ....^...>..,............. 43

texana Credner, 1875.........;... , .. 4 .. ;. ;.. ;. ;.......... 40

texana Clark=Salenia texana Credner.................... 40

tumidula Clark, 1891 '.. ................................ 41

Spatangus sp* Morton, 1829=Cardiaster cinctus (Morton)...... 75

sp. Morton, 1830=Hemiaster parastatus (Morton) and. Hemiaster ungula (Morton).................................. 83,85

cor-marinuin (?) Morton, 1830=Hemiaster parastatus (Morton) ................................................. 83

parastatus Morton, 1833=Hemiaster parastatus (Morton)., 83

parastatus Morton, 1834=Hemiaster parastatus (Morton) t * 83

parastatus Bronn, 1848=Heiniaster parastatus (Morton)..: 83

Stella Morton, 1830=Hemiaster stella (Morton) ....... m.. 84

Stella Morton) 1834=Heiniaster stella (Morton),.....»... 4 . 84

ungula Morton, 1833=Heiniaster ungula (Morton) .....,.,. 85

ungula Morton, 1834=Hemiaster ungula (Morton).......... 85

uugula Bronn, 1848=Hemiaster ungula (Morton) ......... 85

Stoinechinus Hyatti Clark ................................... 56

Toxaster elegans Conrad, 1857=Epiaster Whitei Clark .......... 82

elegans Gabb, 1859=Epiaster elegans (Shumard)........... 80

elegans Meek, 1864=Epiaster elegans (Shuinard)........... 80

texanus Eoemer, 1849=Enallaster texanus (Eoenier)....... 78

texauus Eoemer, 1852=Enallaster texanus (Eoemer) ...... 78

texanus Conrad, 1857=Enallaster texanus (Eoemer)....... 78

texanus Gabb, 1859=Enallaster texauus (Eoemer).......... 78

texanus Meek, 1864=Enallaster texanus (Eoemer)......... 78

ungula Giebel, 1853=Enallaster texanus (Eoemer)'........ 78

Trernatopygus crucifer (Morton)............................... 63

crucifer d'Orbigny, 1853-'60=Trematopygus crucifer (Morton) ................................................... 63

crucifer Clark=Trematopygus crucifer (Morton)........... .63

Uintaerinus socialis Grinuell, 1876 ........................... 21

socialis Meek, 1876=Uintaerinus socialis Grinnell......... 21

eocialis Clark=Uintacrinus socialis Grinnell.............. 21

PLATES.

In consequence of a nvistaico in drawing, the forms the upper and lower viewa of (.he tests of the 

H.olasteridio and Spatangidte are inverted ou the platea.-.

«. 103

PLATE I.

105
PLATE i.

UINTACRINUS SOCIA.LIS Griuuell (page 21).

Fig. la. Laterial view of the test, with interradial area central, natural size. 

1Z». Test with arms.

lc. A radial area, magnified two diameters. 

106
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. I

Ic

UINTACRINUS.
PLATE II.

107
PLATE II.

UINTACRINUS sociALip Grinnell (page 21).

Fig. la. Diagram showing the structural arrangement of the plates in the test. 

1ft. Specimen showing basals and portions of radial and interradial areas, 

ic. Lateral view of arm with attached pinnules. 

Id. Zizygial surface of brachial plate, 

le. Articular surface of brachial plate. 

108
U. fi. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. I

la.

UINTACRINUS.
PLATE III.

109
PLATE III.

BOURGUETICRINUS ALABAMENSis De Loriol (page 25).

Fig. 1ft. Side view of the basal cone magnified five diameters.

Ib. Upper surface magnified six diameters.

Ic. Lower surface magnified six diameters.

PENTACRINUS ASTEUISCUS Meek & Hayden (page 26).

Fig. 2ft. Column with attached pinnules.

2&. Upper surface of a detached plate of the column. 

2c. Lateral view of a portion of the column. 

2d. Enlarged pinnule.

PENTACIUNUS BHYANI GaM) (page 28).

Fig. 3«. Upper surface of a detached plate of the column. 

3&. Lateral view of a portion of the column.

PENTACRINUS WHITEI Clark (page 27).

Fig. 4a. Upper surface of a detached plate of the column. 

4&. Ditto.

4c. Lateral view of a portion of the column. 

' 110
U. S. GEOLOGICAL SURVEY BULLETIN NO, 97 PL. IN

la,

4ft 4c

ZdL

BOURGUETICRINUS AND PENTACRINUS.
PLATE IV.

in
PLATE IV.

OPHIOGLYPHA BRIDGERKNSIS (Meek) (page 29 X

Fig. la. Skeleton, natural size.

1&. Enlarged view of a portion of the upper surface. 

Ic. Enlarged view of a portion of the lower surface.

OPHIOGLYPHA TEXANA Clark (page 30).

Fig. 2a. Skeleton. - t 

2b. Enlarged view of a portion of the upper surface, 

112
BULLETIN NO. 97 PL. IV

OPHIOGLYPHA.
/ v *: :, vv-vPLATE V.

Bull, 97 S H3
PLATE V. 

GQNIASTER MAMMIL.LA.TA Gabb (page 32).

Fig. la-#. Views from various sides of four different plates; magnified two diameters. 

1/t. Greatly magnified surface of plate.

ASTKKIA.S DUBIOM Whitfield (page 31).

Fig. 2. Gutta-percha cast of three individuals. 

114
U. 8. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. V

la.

Ic

r 'f ' 

r^ 

HI

Ib

le

GONIASTER AND ASTERIAS.
115
PLATE VI.

CIDARIS CAUFORNICUS Clark (page 36).

Fig. la. Spine, enlarged.

1Z>. Ditto. 

. Ic. Articular surface of Ib, much enlarged.

CIDARIS TAYLORENSIS Clark (page 35). ,

Fig. 2o. Fragment of twq contiguous interambulacral plates of the same series. 

2b. Spine.

CIDARIS SPLENDENS Morton (page 33),

 ;

Fig. 3«. Portion of test, natural size.

36. Interambulacral plate, magnified two diameters,

3c. Ambulacral area, highly magnified,

3d. Tubercle, enlarged.

3e. Spine,

3/. Base of same much enlarged.

30. Articular surface of spine.

CIDARIS WALCOTTI Clark (page 37),

Fig. 4a. Portion of test, natural size.

4&. Interambulacral plates, enlarged. 

4c. Ambulacral area, highly magnified; 

4d. Tubercle, enlargedr

116
BULLETIN NO. 97 PL. VI

Jc

2b

4b
PLATE VII.

117
Tlf.

CIDARTS TEXANUS Clark (page 36).

Fig. la. Test restored, natural size.

Ife. View showing the arrangement of the interamhulacral plates in the vicinity

of the apical disk, with adjacent ambulacral plates. 

Ic. Portion of ainbulacral area, enlarged: 

Id. Inter ambulacral plate, enlarged, 

le. Tubercle, much enlarged.

LEIOCIDARIS HEMIGRANO^US (Shuniard) (page 38)^

Fig. 2a. Interambulacral plate.

2b. Portion of ambulacral area, enlarged. 

2c. Tubercles, magnified two diameters. 

2d. Apical disk, enlarged. 

118
U. 8. GEOLOGICAL SURVEY BULLETIN «O. 97 PL. VII

C1DARIS AND LEIOCIDARIS.
PLATE VIII.

119
PLATE VIII.

LEIOCIDARIS HEMIGRANOSUS (Shumard) (page 38).

Fig. la. Upper surface of the test, natural size. 

16. Lateral view of the same. 

120
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. VIII

LEIOCIDAR1S.
PLATE IX.

121
LEIOCIDARIS HEMIGRANOSUS (Shuiuard) (page 38),

Fig. la. Upper surface of the test. 

16. Lower surface of the test. 

Ic. Lateral view of the same. 

122
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. IX

ic

LEIOCIDARIS.
PLATE X,

123
PLATE X.

SALENIA TEXANA Credner (page 40).

Fig. la. Upper surface of the test, natural size. 

1Z». Under surface of the same. 

Ic. Lateral surface of the same. 

Id. Interambulacral area, magnified two diameters, 

le. Anibulacral area, magnified three diameters. 

I/. Portion of the same, highly magnified. 

\g. Apical disk, enlarged, 

Ifc. Tubercle, enlarged. 

124
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. X

Ih

lei

SALENIA.
'» I

PLATE XI.
PLATE XI.

SALENIA TUMIDULA Clark (page 41).

JTig. la. Upper surface of test, magnified two diameters;. 

1.6. Under surface of the same. 

J.c. LateraJ. surface of the ,sain.e. 

Id. Inter ambulacra 1 area, magnified four diameter^, 

le. Single plate of same, highly magnified. 

3/. Ambulacral area, highly magnified. 

Ig. Apical disk, enlarged. 

lih. Genital plate of same, highly magnified. 

li. Mouth opening, enlarged. 

Ij. Tubercle, enlarged.

SALENIA BELLULA Clark (page 43).

Fig. 2a, Upper surface of test, magnified two diameters. 

-26. Under surface of the same, 

2c. Lateral surface of the same.

** 2d. Three interambulacral plates, highly magnified. 

2e. Three ambulacral plates, highly magnified. 

2/. Apical disk, enlarged. 

2g. Tubercle, highly magnified., 

126
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XI

Ji

SALENIA.
PLATE

127
PLATE XII.

HEMICIDARIS INTUMESCENS Clark (page 44).

Fig. la. Upper surface of the test.

1Z>. Lower surface of the test.

Ic. Lateral view of the same.

Id. Two interambulacral plates, highly magnified.

le. Lower portion of interambulacral area, enlarged.

I/. Upper portion of same. «

Ijf. Portion of ambnlacral area, magnified.

17). Tubercle, from above,

li. Lateral view of the same.

PSEUDODIADEMA EMERSON! Clark (page 45.

Fig. 2a. Lateral view of the test.

2b. Portion of the interambulacral area, enlarged. 

2c. Portion of the ambulacral area, enlarged, 

2d. Tubercle, from the side. 

2e. The same, from above,

123 *
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL, XII

1C lb

If

HEMICIDARIS AND PSEUDODIADEMA.
PLATE XIII.

129 

Bull. 97 9
PLATE XIII.

PSEUDODIADEMA DIATRETUM (Morton) (page 46).

Fig. la. Under surface of twst. 

1Z>. Lateral view of the same.

Ic. Two interambulacral plates, magnified four diameters. 

Id. Ambulacra! plates, highly magnified, 

le. Ditto. 

I/. Tubercle, much enlarged.

PSEUDODIADEMA TEXANUM (Roemer) (page 47).

Fig. 2«. Upper portion of the interambulacral areai, highly magnified. 

2Z>. Portion of ambulacral area, ditto. 

139
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XII.

la.

le

PSEUDODIADEMA.
PLATE XIV

131
PLATE XIV.

PSEUDODIADEMA TEXANUM (Roemer) (page 47).

Fig. la. Upper surface of the test. 

16. Lower surface of the same. 

Ic. Lateral surface of the same. 

Id. Interamlmlacral area, enlarged. 

le. Ambulacra! area, enlarged. 

If. Three interanlbulacral plates, highly magnified. 

Ig. Tubercle, much enlarged. 

132
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XIV

If

Ib

PSEUDODIADEMA.
PLATE XV.

133
PLATE XV.

DIPLOPODIA TEXANUM (Roemer) (page 48).

Fig. 10. Upper surface of the test. 

16. Lower surface of the same. 

le. Lateral surface of the same. 

Id. Ambulacral area, enlarged, 

le. Four plates of the same, highly magnified. 

I/. Interambulacral plates, ditto. 

134
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XV

le

DIPLOPODIA.
PLATE XVI.

135
PLATE XVI.

DIPLOPODIA TEXANUM (Roemer) (page 48).

Fig. la. Lower portion of ambulacral area, highly magnified. 

16. Upper portion of interamhulacral area, much enlarged. 

Ic. Lower portion of same, ditto. 

Id. Tubercle.

DIPLOPODIA HILLI Clark (page 50).

Fig. 2«. Upper surface of the test. 

26. Lower surface of the same. 

2c. Lateral surface of the same. 

2d. Upper portion of an ambulacral area, enlarged. 

2e. Three plates of the same, highly magnified. 

2/. A portion of an interambulacral area, highly magnified. 

20. Tubercle. 

136
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XVI

DIPLOPODIA.
PLATE XVII.

137
PLATE XVII.

COPTOSOMA MORTONI (de Loriol) (page 51).

Fig. !«.' Upper surface of the test. 

1Z». Lateral vie^f of the same. 

Ic. Three auibulacral plates, much enlarged. 

Id. luterambulacral nrea, enlarged, 

le. Three iuteramhulacral plates, much enlarged.

138
U. S. GEOLOGICAL SURVEY BULLETIN MO. 97 PL. XVII

Ic

COPTOSOMA.
PLATE XVIII.

139
PLATE

COPTOSOMA SPECIOSUM Clark (page 52).

Fig. la. Upper surface of the teat. 

11). Lateral view of the same.

Ic. Upper portion of an iuterambulacral area, enlarged. 

Id. Three plates of the same, highly magnified. 

He. Portion of ambuhicral area, highly magnified. 

I/. Ditto.

Ig. Tubercle of anibulacral area, 

l/i. Tubercle ofinteranibulacral area.

GONIOPYGUS ZITTELI Clark (page 53).

Fig. 2a. Lateral surface of the test.

26. Lower portion of ambulacral area, highly magnified. 

2c. Portion of interanibulacral area, .highly magnified. 

2d. Apical disk, enlarged. 

140
U. S. GEOLOGICAL SURVE* BULLETIN NO. 97 PL, XVIII

Ih

COPTOSOMA AND GONIOPYGUS.
PLATE XIX.

141
PLATE XIX.

GONIOPYGUS ZITTELI Clark (page 53)

Fig. la. Upper surface of the test. 

16. Lower surface of the same. 

Ic. Interauibulacral area, enlarged. 

Id. Ambulacra! area, enlarged, 

le. .Tubercle. 

142
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XIX

GONIOPYGUS.
PLATE XX.

143
PLATE XX.

PSAMMECHINUS CINGULATUS Clark (page 55).

Fig. la. Upper surface of the test. 

1Z>. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Interambnlacral area, enlarged. 

\e. Three plates of the same, highly magnified. 

I/. Ambulacra! area, enlarged. 

\g. Four plates of the same, highly magnified. 

1ft.. Mouth opening, enlarged, 

li. Tubercle. 

144
BULLETIN NO. 07 PL. XX

PSAMMECHINUS.
PLATE XXI.

Bull. 97 10 145
PLATE XXI.

PEDINOPSIS PONDI Clark (page 57).

Fig. lo. Upper surface of the test. 

Ifc. Lateral view of the same. 

146
BULLETIN NO. 97 PL. XXI

la.

PEDINOPSIS.
PLATE XXII.

147
PLATE XXII.

PEDINOPSIS PONDI Clark (page 57).

Fig. la. Lower surface of the test.

1&. Four interambulacral plates, much enlarged. 

Ic. Four ambulacral plates, highly magnified.

148
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXII

r^Sjps.yv.., -(jr.'..-..-. >\" \

,

Jc

PEDINOPSIS.
149
XXIII.

STOMECHINUS HYATTI Clark (page 56).

Fig. la. Lateral surface view of the -test, slightly distorted. 

1Z». Portion of the ambulacral area, enlarged. 

Ic. Portion of the interambulacral area, enlarged. 

Id. Tubercle from above, highly magnified. 

le. The same from the side.

HOLECTYPUS PLANATUS Roemer (page 58).

Fig. 2a. Upper surface of the test. 

2b. Lower surface of the same. 

2c. Lateral surface of the same. 

2d. Two interambulacral plates, enlarged. 

2e. Portion of the ambiilacral area, highly magnified,

2f. Apical disk, enlarged. 

150
BULLETIN NO. 97 PL. XXIII

\i>

STOMECHINUS AND HOLECTYPUS.
PLATE XXIV.

151
PLATE XXIV.

PYRINA. PARRYI Hall (page 59).

Fig. la. Upper surface of the test. 

16. Lower surface of the same. 

Ic. Side view of the same. 

Id. Posterior view of the same. 

le. Portion of an ambulacral area, enlarged. 

If. The same further enlarged.

Ig. Two interambulacral plates, magnified three diameters. 

Ih. Portion of single interambulacral plate, highly magnified, 

li. Apical disk, enlarged. 

Ik. Portion of the madreporite, highly magnified.

152
U. S. GEOLOGICAL SURVEY
PLATE XXV.

153
PLATE XXV.

BOTJUOPYGUS AT.ABAMENSIS Clark (page 60).

Fig. la. Upper surface of test. 

Ifc. Lower surface of test. 

Jc. Side view of the same.

Id. Portion of an ambulacral area at base of petaloidal region, enlarged, 

le. Same in center of petaloidal region, highly magnified. 

I/. An interambulacral plate, highly magnified.

154
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXV

BOTRIOPYQUS.
PLATE XXVI.

155
PLATE XXVI.

ECHINOBRISSUS EXPANSUS Clark (page 61).

Fig. la. Upper surface of the test. 

16. Lower surface of the test. 

Ic. Side view of the same. 

Id. Posterior view, showing anal sulcus. 

\e. An iuterambulacral plate, enlarged.

I/. Portion of the petaloidal region of the right autero-lateral ambulacral area. 

10. Apical disk, enlarged.

ECHINOBRISSUS TKXANUS Clark (page 62).

Fig. 2a. Upper surface of the test. 

21). Lower surface of the test. 

2c. Side view of the same. 

2d. Posterior view, showing anal sulcns. 

2e. Portion of the -right ariterb-latefal ambulacrum. - 

2/. Four interaulbulacral plates, highly magnified.

156
BULLETIN NO. 97 PL. XXVI

2c

ECHINOBRISSUS.
PLATE XXVII.

167
PLATE XXVII.

TREMATOPYGUS CRUCIFER (Morton) (page 63).

Fig. la. Upper surface of the test. 

16. Lower surface of the test. 

le. Side view of the same. 

Id. Posterior view of the same.

le. Lower portion of the petaloidal region of the right postero-lateral ambulacrum.

If. Much enlarged view of several plates of the same. 

Ig. Apical disk, enlarged. 

Ik. Tubercle from above, 

li. Lateral view of the same.

CATOPYGUS OVIFORMIS Conrad (page 64).

Fig. 2a. Upper surface of the test. 

26. Lower surface of the test. 

2c. Lateral view of the same; 

2d. Posterior view of the same. 

2e. Right postero-lateral ambulacrum, enlarged. 

2/. Several plates of the same, highly magnified.

CATOPYGUS PUSILLUS Clark (page 65).

Fig. 3a. Upper surface of the test. 

36. Lower surf ace of the test. 

3c. Lateral view of the same. 

3d. Posterior view of the same. 

158
U. 8. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXVII

TREMATOPYGUS AND CATOPYGUS.
PLATE XXVIII.

159
PLATE XXVIII.

CASSIDULUS FLOREALIS (Morton) (page 66).

Fig. la. Upper surface of the test. 

Ib. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Posterior view of the same. 

\e. Right postero-lateral ambulacrum.

If. Several plates in the petaloidal region of the same, much enlarged. 

Ig. Ditto, lower surface. 

1/t. Posterior interambulacrum. 

li. Single plate, much enlarged. 

I/. Apical disk, highly magnified. 

lie. Tubercle from above. 

I/. Lateral view of the same. 

160
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXVIII

iff

CASSIDULUS.
PLATE XXIX.

Bull, 97 11
PLATE XXIX.

CASSIDULUS ^QUOHKUS Morton (page 68).

Fig. la. Upper surface of the test. 

16. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Posterior view of the same. 

le. Anterior ambulacrum.

I/. Several plates, petaloidal region of the same, much enlarged. 

1</. Ditto, oral region. 

Ih. Apical disk, much enlarged, 

li. Diagram showing the arrangement of the plateq about the peristomia^

opening, * 

162
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXIX

le VI

la.

CASSIDULUS.
PLATE XXX.

163
PLATE XXX.

CASSIDULUS MICROCOCCUS Gabb (page 69).

Fig. la. Upper surface of the test. 

1&. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Posterior view of the same.

le. Anterior ambulacrum at the base of the petaloidal region. 

If. Several plates in petaloidal region of anterior ambulacrum, much enlarged, 

Ig. Oral portion of an ambulacral area. 

lh. Apical disk, enlarged, 

li. Surface of an interambulacral plate, highly magnified,

164
U. G. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXX

CASSIDULUS.
PLATE XXXI.

165
PLATE XXXI.

CASSIDULUS SUBQUADRATUS Conrad (page 70).

Fig. la. Upper surface of the test. 

1Z>. Lower surface of the test. 

le. Lateral view of the same. 

Id. Posterior view of the same.

le. Lower portion of the petaloidal region of the right antero-lateral ambulacrum.

If. Several plates of the same, much enlarged. 

10. Oral portion, much enlarged. 

Ih. Apical disk, enlarged.

166
BULLETIN NO. 97 PL. XXXI

K

Jo,

t"

r-'-

ii/f^f-^

OASSIDULUS.
PLATE XXXII.

167
PLATE XXXII.

CASSIPULUS SUBCONICUS Clark (page 71).

Fig. la. Upper surface of the test. 

1&. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Posterior view of the same. 

le. An ambulacral area, enlarged.

I/. Several plates of the petaloidal portion, highly magnified. 

!</. Ditto, oral portion.

Ife. Diagram showing the arrangement of the plates arotind peristomial opening, 

li. Interanibulacral plate, much enlarged.. 

It. Apical disk, much enlarged. 

168
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXXII

lb

CASSIDULUS.
PLATE XXXIII.

169
PLATE XXXIII.

CASSIDULUS PORRECTUS Clark (page 72).

Fig. la. Upper surface of the test. 

16. Posterior view of the same. 

170
BULLETIN NO. 97 PL. XXXII

CASSIDULUS.
PLATE XXXIV.

171
PLATE XXXIV.

CASSIDULUS PORRECTUS Clark (page 72).

Fig. la. Lower surface of the test. 

' 1ft. Lateral view of the same. 

172
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXXIV

CASSIDULUS.
PLATE XXXV.

173
PLATE XXXV.

CASSIDULUS PORRECTUS Clark (page72).

Fig. la. An ambulacral area, enlarged.

16. Lower portion of petaloidal region, highly magnified.

Ic. Central portion of same, highly magnified.

Id. Three interambulacral plates, much enlarged.

CASSIDULUS STANTONI Clark (page 73).

Fig. 2o. Upper surface of the test. 

26. Lower surface of the test. 

2c. Lateral view of the same. 

2d. Posterior view of the same. 

174
BULLETIN NO. 37 PL. XXXV

Ic

2b

CASSIDULUS.
PLATE XXXVI.

175
PLATE XXXVI.

ANANCHYTES OVAXIS Clark (page 74).

Fig. la. Upper surface of the test. 

1&. Lower surface of the same. 

Ic. Lateral view of the same. 

Id. Anterior view of the same, 

le. Posterior view of the same. 

I/. Apical disk, enlarged. 

Ig. Ambulacral plates, much enlarged. 

Ih. Interambulacral plates, much enlarged, 

176
U. 3. GEOLOGICAL SURVEY BULLETIN NO- 97 PL. XXXVI

ANANCHYTES.
PLATE XXXVII.

Bull. 97 12 177
PLATE XXXVII.

CARDIASTER'CINCTUS (Mortou) (page 75).

Fig. la. Upper surface of the test. 

U. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Anterior view of the same, 

le. Posterior view of the same.

I/. Central portion of the petaloid;il region of :in ambulacra! area, much enlarged.

!</. Basal portion, ditto. 

1/t. Apical disk, enlarged.
U. 8. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXXVM

CARDIASTER.
PLATE XXXVIII.

179
PLATE XXXVIII.

HOLASTER SIMPLEX Shumard (page 76).

Fig. la. Upper surface of the test. 

1&. Lower surface of the same.

lc.. The right antero-lateral ambulacrum, enlarged. 

Id. Portion of the petaloidal region of the same. 

\e. Four basal plates of the same. 

If. Apical disk, enlarged. 

Ig. Tubercle, highly magnified. 

180
U. S. QEOLOQICAL SURVEY BULLETIN NO. 97 PL. XXXVIII

-?<*

la.
PLATE XXXIX.

181
PLATE XXXIX.

HOLASTKK SIMPLEX Shumard (page 76).

Fig. la. Lateral view of the test. 

lb. Posterior view of the same. 

Ic. Interambulacral plate, much enlarged. 

Id. Tubercle, highly magnified.

ENAXLASTEU TKXAJSTUS Roemer (page 78).

Fig. 2a. Upper view of the test. 

2Z>. Lower view of the test. 

2c. Lateral view of the same v 

2d. Posterior view of the same. 

2e. Portion of the petaloidal region of the right antero-lateral ambulacrum,

much enlarged.

2f. Ditto, anterior ambulacrum. 

2g. Apical disk, enlarged.

182
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XXXIX

la.

HOLASTER AND ENAULASTER.
S8T
PLATE XL.

ENALLASTER OBLIQUATUS Clark (page 7$).

Fig. la. Upper surface of the test. 

U. Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Posterior view of the same.

le. Portion of the petaloidal region of the anterior ambulacrum. 

I/. Ditto, left anterior ambulacrum. 

Ig. Second plate of the same from the mouth opening. 

1ft. Diagram showing arrangement of plates about the mouth opening. 

li. Apical disk, enlarged. 

Ik, Tubercle from above, much enlarged. 

II. Lateral view of the same. 

184
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XL

Ic

ENALLASTER.
PLATE XLI.

185
. PLATE XLI. 

EPIASTKR ELKGANS (Shumard) (page 80).

Fig. la. Upper surface of the test. 

Ifc. Lateral view of the same. 

 186
U. 8. GEOLOGICAL SURVEY BULLETIN NO- 97 PL. XLI

la.

EPIASTER.
PLATE XLIL

187
PLATE XLH.

EPIASTER ELEGANS (Shumard) (page 80).

Fig. la. Lower surface of the test. 

1ft. Posterior view of the same. 

188
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLil

la.
PLATE XLIII.

189
PLATE XLIII.

EPIASTKK ELEGANS (Shumard) (page 80).

Fig. la. Upper portion of the anterior ambulacrum, enlarged.

16. Middle portion of the petaloidal region of the anterior ainbulacrniu^highly

magnified.

Ic. Ditto, left antero-lateral ambulacrum. 

Id. Two interambulacral plates, much enlarged, 

le. Apical disk, enlarged.

EPIASTEK WHITEI Clark (page 82).

Fig. 2a. Lateral view of the test. 

26. Posterior view of the same. 

2c. Left autero-lateral ambulacrum, enlarged.

2d. Diagram showing the arrangement of the plates in the apical disk and 

bordering areas.

190
BULLETIN NO. 97 PL. XLIM

1C
PLATE XLIV.

191
PLATE XLIV.

EPIASTEU WHITEI Clark (page 82).

Fig. la. Upper surface of the test.

16. Lower surface of the same.

Ic. Eight antero-lateral interambulacral area, much enlarged.

Id. Lower portion of the petaloidal region of the right antero-lateral ambulacrum, highly magnified.

\e. Several plates of the petaloidal region of the left antero-ambulacrum.

I/. Peristomial opening, with surrounding ambulacra! and interambulacral 

plates.

\g. Apical disk, much enlarged. 

192
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLIV

Jc

Jd.

la.

EPIASTER.
PLATE XLV.

Bull. 97 13 193
PLATE XLV.

HEMIASTEU PARASTATUS (Morton) (page 83).

Fig. la. Upper surface of the test. 

Ifc. Lower surface of the test. 

Ic. Lateral view of the same. 

\d. Posterior view of the same, 

le. Anterior ambulacrum, enlarged.

I/. Portion of petaloidal region of the same, highly magnified. 

lg. Portion of basal region, ditto.

17t. Several plates from the petaloidal region of the right antero-lateral ambulacrum, much enlarged.

li. Three interambulacral plates, with fasciole. 

Ik. Portion of fasciole, highly magnified. 

II. Tubercle from the side. 

1m. Ditto from above. 

In. Apical disk, enlarged.

194
U. 8. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLV

let.

HEMIASTER.
PLATE XLVI.

195
- PLATE XLVI.

HEMIASTER STELLA (Morton) (page 84).

**

Fig. la. Upper surface of the test.

1ft. Lower surface of the test. 

Ic. Lateral view of the same.

Id. Posterior view of the same.

HKMIASTEU UNGULA (Morton) (page 85).

Fig. 2c. Upper surface of the test.

2&. Lower surface of the test.

2c. Lateral view of the same.

2d. Posterior view of the same.

2e. Portion of the petaloidal region of the right antero-lateral ambulacrum,

	much enlarged.

2/. Ditto, anterior ambulacrum.

2g. Apical disk, enlarged.

196
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLVI

Ic

20.

fl*1 ' J" >^1 "]

Set.

HEMIASTER
PLATE XLVII.

197
PLATE XLVII.

HEMIASTEK TEXANUS Roemer (page 86).

Fig. la. Upper surface of the test. 

li». Lower surface of the test. 

Ic. Lateral view of the same. 

Id. Posterior view of the same.

le. Several plates from the petaloidal region of the right postero-lateral ambulacrum, highly magnified. 

If. Ditto, anterior ambulacrum. 

Igt Apical disk, much enlarged. 

1/j. Lateral view of a tubercle, highly magnified, 

li. Same from above. 

198
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLVII

Jit

HEMIASTER.
PLATE XLVIII.

199
PLATE XLVIII.

HEMIASTKR HUMPHRKYSANUS (Meek and Hayden) (page 88).

Fig. la. Upper snrfoce of the test.

Ife. Lower surface of the test.

Ic. Lateral view of the same.

Id. Posterior view of the same.

le. Several plates from the petaloidal region of the right posterior lateral am- 

	bulacrum, highly magnified. 

I/. Ditto, anterior ambulacrum.

HEMIASTKK DALLI Clark (page 89).

Fig. 2a. Upper surface of the test. 

21). Lower surface of the test. 

2c. Lateral view of the same. 

2d. Posterior view of the same.

2e. Several plates from the petaloidal portion of the left antero-lateral ambulacrum. 

200
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLVIII

Ib

le

.2b

HEMIASTER.
PLATE XLIX.

201
PLATE XLIX.

HKMIASTKR CALIFORNICUS Clark (page 90).

Fig. la. Upper surface of the test.

11). Lower surface of the test.

Ic. Lateral view of the same.

HEMIASTEK <?ALVINI Clark (page 90).

Fig. 2a. Upper surface of the test. 

2Z>. Lower surface of the same. 

2c. Lateral view of the same. 

2d. Posterior A'iew of the same.

2e. Several plates from the petaloklal region of the right postero-lateral ambulacrum, highly magnified. 

2/. Same, lower portion of petaloidal region. 

2g. Several plates from anterior ambulacrum. 

2h. Interamhulacral plate, eularged. 

21. Apical disk, enlarged.

202
U. S. GEOLOGICAL SURVEY BULLETIN NO. 97 PL. XLIX

2e

HEMIASTER.
PLATE L.

203
PLATE L.

LINTHIA TUMIDULA Clark (page 91).

Fig. la. Upper surface of the test. 

11). Lower surface of the same. 

Ic. Lateral view of the same. 

Id. Posterior view of the same.

le. Upper portion of the anterior ambulacrum, enlarged.

If. Several plates from the petaloidal region of the left postero-lateral ambulacrum, highly magnified. 

!</.- Apical disk, enlarged, 

l/i. Tubercle from the side, highly magnified, 

li. Ditto, from above. 

204
U. 8. GEOLOGICAL SURVEY BULLETIN NQ. 97 PL, L

If

LINTHIA.
INDEX.

A. Page.'

Ananchytes................................ 74-75

 oinotus................................. 75

cruciferus.............................. 63

fimbriatus ............................. 75

 ovalis...............................74-75,176

Sf...................................... 75

Apiocrinidae ............................... 24-25

Arbaciasp................................. 92

Asterias ................................... 31-32

? dubium............................31-32,114

Asteroidea................................. 29-33

B.

Botriopygus............................... 60-61

alabamensie......................... 60-61,154

elevatus ............................... 61

Bourgueticrinus........................... 25

alabamensis............................25,110

ellipticns .............................. 25

C.

Cardiaster ................................. 75-76

cinctus..............................75-76,178

fimbriatus ............................. 75

Carpenter, P. B.., cited on Pentacrinidse.... .25-26

Cassidulidse................................ 59-73

Cassidulus................................. 66-73

abruptus............................... 92

aequoreus ........................ 67,68-69,162

sequorum.............................. 68

florealis.............................66-67,160

miorococcus.........................69-70,164

porrectus .......................72-73,170-174

Stantoni ...............................73,174

subconicuB....................... 67,71-72,168

snbquadratus.................... 70-71,72,166

Catopygus................................. 64-66

columbariuB........................... 65

oviformis ........................64-65,66,158

pusillus.............................65-66,158

Cidaridce................................... 33-40

CidariB..................................... 33-38

armiger ..................s.............. 33

Branneri............................... 37

californicus ........................35,36,116

clavigera............................... 46

diatretum.................... /> ......... 40,46

hemigranosns.......................... 38

nahalakensis .......................... 92,93

sceptrifora............................. 46

aceptrifera compared with C. texanua . 37

Cidarls Continued.

serrata ...... .......................... 34

(?)sp .................................. 33

splendens...........................33-35,116

splendeus.............................. 33,34

Taylorensis .................. v.......... 35,116

texanus ...... ......................36-37,118

Waleotti.......... ~................. 37-38,116

Cidarites armiger.......................... 33

diatretum....... 1. ..................... 46

splendens .............................. 33-35

Clypeaster florealis ........................ 66

geometricus............................ 92,93

Kp...................................... 66,92

Coptoaoma................................. 51-53

Mortoni......................... 51-52,53,138

specioaum'.......................... 52-53,140

Crinoidea.................................. 21-29

Cypboaoma texanam....................... 48,49

D.

Diadema sp................................ 92

texanum............................... 47,48

Diadematidas............................... 44-54

Diplopodia................................. 48-51

Diplopodia Hilli........................ 50-51,136

texanum....................... 48-50,134-138

Discoidea oooid'entale ...................... 92,93

E.

Echinidse .................................. 54-58

Echinobrissus.............'................. 61-63

cruciferus.............................. 63

expansus .......'................ 61-62,63,156

texanus............................ 62-63,156

Echinoconiilze ............................. 58-59

Echinoidea................................. 33-93

Echinus andinus........................... 54

Bolivarii ............................... 50

patagonensis........................... 54

sp...................................... 33

Enallaster ................................. 78-80

mexicanus, related to E. obliquatus ... 80 

obliquatus......................... 79-80,184

peruvianus ............................ 79

texanus...................... 78-79,80,82,182

texasus................................ 78

Epiaster................................... 80-84

elegans........................ 80-82,186-190

"Whitei...................... 81,82-83,190-192

Euechinoidea .............................. 33-93

205
206 INDEX.

F.

Page

Faujasia florealis .......................... C6

G.

Goniaster.................................. 32

mammillata........................... 32,118

Goiiiopygus ......:........................ 53-54

major.................................. 54

Zitteli ........................... 53-54,140-142

H.

Hamites Fremontii. ................t....... 83

Hemiaster ................................. 84-91

aniericanus ............................ 80,87

Dalli.-.................................89,200

elegaiis ................................ 81

califoruicus............................90, 202

Calvini .............................90-91, 202

. Humphreysanus ....................88,90,200

incrassatus ............................ 84,85

parastatus ................... 83-84,85,86,194

Stella............................... 84-85,196

texanns .........................86-87,91,198

ungnla...........................84, 85-86,196

Wetherbyi............................. 84,85

Hemicidaris ............................... 41-45

intumescens ........................44-45,128

Holaster................................... 76-78

cinctus ................................ 75

comanchesi.............................76, 77

fimbriatiis ............................. 75

Ifevis, var. planus ..................... 77

parastatus ............................. 83

simplex.........................76-78,180-182

ungula................................. 85

Holasteridas ............................... 74-78

Holectypus................................ 58-59

CastiMoi ............................... 59

planatus........................... 58-59,150

planus................................. 58,59

simplex................................ 92,93

Leiocidaris ................................ 38-39

hemigranoaus................37,38-39,118-122

hemigranosus, Shumard cited on locality............................... 39

Loriol, P. de, cited on Boiirgueticriuus alabamensis ........................ 25

describes Coptosoina Mortoni.......... 51-52

Lintbia................--...-............-. 91-92

tumidula............................91-92, 204

M.

Macraster texanus ........................ 81

Meek, F. B., describes structure of Uintacriiius ........................... 22

assignsUintacrinus socialis to Niobrara

group............................ 24

Meek & Hayclen first describe Pentacrinus

asteriscns........................ 26

Micra»ter ungula. ... ,..,..,,,,,,,,,,,,,, 85

Page.

Neumayr, on classification of crinoids...... 21

Niobrara group, Uintacrinus socialis assigned by Meek to ............... 24

Nucleolites crucifer......!................. 63

crucifer us............................... 63

oviformis (Catopygus) ................. 64

0. 

Ophioderma bridgerensis .................. 29

Opbioglypha............................... 29-31

bridgerensis ........................29-30,112

texana .. .TT........................ .30-31,112

Ophiuridse.................................. 29-31

Ostrea congesta............................ 24

quadriplicata ........................:. 39

 s

p.

Pediuopsis................................. 57

Poudi............."................. 57,146-148

Pentacriuidfc .............................. 25-29

Pentacrinites asteriscus ................... 26,27

Pentacrinus................................ 26-29

asteriscus........................26-27,28,110

Bryani...'........................... 28-29,110

"Whitei..............................27-28,110

Periaster australis......................... 87

Phymosoma texanuni...................... 48

Psammechinus '..--.-...................... 55

cingulatus .............................55,144

Pseudodiadema ............................ 45-48

Baileyi................................. 46

diatretum, ..........................46-47,130

Emersoni..... ......................45-43,128

Hilli ................................... 50

ornatum ............................... 47

Itbodaui....... ........................ 51

"Kcemeri................................ 47

tenue .................................. 48

texanura.................. 47-48, 49,51,130-132

Pygorhynchus crucifer.................... 63

Pygurus florealis ..................':....... 66

(?) geometricus........................ 92,93

Pyrina..................................... 59-60

Desmoulinaii........................... 60

Parryi..............................59-60,152-

S. 

Salenia..................................... 40-44

bellula...........................42,43-44,126

Desori, comparison of, with S. texana.. 41 

petalifera, comparison of, with S. texana ................................ 41

texaua........................40-41,42,43,124

tumidula .....!.............I...'41,42,43,126

Salenidse................................... 40-44

Shumard, B. F., cited on locality of Leiocidaris hemigranosus................. 39

Spatangidae ............................... 78-92

Spatangus columbianum................... . 79

cor-marinum (?) ....................... 83

parastatus ............................. 83

sp................................... 75,83,85

Stella................................... 84

ungula, ...,.,., , ,,,,. , .,,,. 8«?
' V

INDEX. 207

Stelleridse...... .................

Stomechinua ....................

Hyatti...... ................

nudua .......................

T.

crucifer . . ...................

Paga 

........... 31 33

........... 56

.......... 56,150

........... 56

........... 80.82

78

7fi

........... 63 64

....... 63-64,158

IT.

..................21-24,

W. 

Whitfleld, cited on Asterias ? dubium. . . .

Z. 

Zittel, vou, on Uintacrinidae .... .......

Page.

. 21-24

106-108

. 31-32

21