Bulletin No. 266 Series 0, Systematic Geology and Paleontology, 73 

DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

CHARLES D. WALCOTT, DIRECTOR

PALEONTOLOGY

OF THE

IALONE JURASSIC FORMATION OF TEXAS

BY

FRANCIS WHITTEMORE CRAGIN

 STRATIGRAPHIC NOTES ON MALONE MOUNTAIN AND THE SURROUNDING 

REGION NEAR SIERRA BLANCA, TEXAS

BY

T. W. STANTON

WASHINGTON

GOVERNMENT PRINTING OFFICE

1905

CONTENTS.

Letter of transmittal ......... ^............^.......'...................... 7

Introduction .._.---_._......._--.-._----_-----_-----_-----_-.-.-.---.---- 9

Scope of investigation..____.._.____.....__._._........ ._.._.___-..... 9

Geography of region ...'.. ............................................. 9

History of geological studies .....................'...............^.... 10

Geology of the region .__._.._......;.............._.-.-....___._-...._ 13

Distribution of fossils in the Malone district.......................... 16

Occurrence of species by localities..-...-..--..-.--..----.-...--... 16

Age of Malone fauna ................ ................................ 19 , Localities o.f related faunas .-...-.-.-.--...........-.-........-.--.:- 21

Acknowledgments ................... ....'........ ^................... 22

Strati graphic notes on Malone Mountain and the surrounding region, near

Sierra Blanca, Tex.,by T. W. Stan ton.................................. 23

General remarks..........--.....-.-.-..-..------..-.--.-..---.....-... 23

Malone Mountain and the Jurassic ...;............:.....-.--...-..-.. 24

The Cretaceous .-..........-.....-......----..--.--..--.--'..---.-.... 28

Quitman Mountains .....-..--.-..--------------..-....-......... 28

The Rio Grande section.... ...................................... 30

Eagle Mountains ................................-.........:.'..... 32

Sierra Blanca.... ................................................ 32

Finlay Mountains....-....-.-..---.--.-..-.....'.....-.-.......... 32

Other localities ..................j--.-.....^. ................... 32

Descriptions of the species ....... .^....................................... 34

Ccelenterata .................................. ^...................... 34

Anthozoa.---....-...------.-.--..----.--..---.-----...-.-....-.. 34

Echinodermata ...........-.......-.--..---..--..-..-.---.-........--. 35

Echinoidea ............. ...._--...---...--....--..-.---.---..--. 35

Holectypoida................................................. 35

Spatangoida............--.-..-...-...--....-.-.---.-....-.-. 36

Vermes.............................................................. 37

Annelida.................................. .....-.---......-..-... 37

Tubicola................................. .................... 37

Molluscoidea ..-.-..............'--.....---...-......--.-.---.----...-. 38

Bryozoa..---.......................-.-...-..'.-.-...-..-..-.-..--.. 38

Diastoporidae . -..-.--.---...-..--...-..--....--....----.--.-.. 38

Mollusca .... ...--..........-.--..-.-...-.....--......--.-..-.-.----.-. 39

Pelecypoda....................................................... 39

Ostreidae ...........................^........_................ 39

Spondylidae ............-.---.-.-..-----.-.- ..-.-.-...-.-...--.. 43

Limidse - ........-.......-..........._.....-..-....-.-.--.... 43

Pectinidse --.....-.......------..-....---..-..-.--......---.. 44

Aviculidae -.'.......-....---------...--.--...----.--.---.---.. 46

MytilidaB...............-..__.-.........................-.... 48

3
4 CONTENTS.

Descriptions of the species Continued. Page. 

Mollusca Continued. -

Pelecypoda Continued.

Pinnidse..................................................... 49

Arcidae --._---_.._.__--......__..._.__...--..---._..__..___ 50

Nuculidse --------._.--.___..__...__.. ._.-.'..--.._._..!___.._. 55

Trigoniidae .--.....----.........-.__.....--.,--....--........ 56

Astartidae -.-----.-.--....._._._..__._...---..-.-..---...--._. 64

Crassatellidae .-._---.-.--_--._._..__._._.-__--..._-.-....-___ 69

Lucinidse..-.-..-.-...-..-._........... ....................... 72

Cyprinidse......,.....--...---...-..........-._.....-....-.-... 7?

Veneridse..----..-.....--.--............--.......-----........ 79

Pholadomyidae................................................ . 79

Anatinidse..................................................... 85

Myidffi ...................................................... 87

Pholadidae................................................... 87

Gastropoda....................................................... ^ 88

Pleurotomariidse............... ........... r ................... 88'

Trochidte....... .......................... ............ .......:._ 88

Neritidse .............,..............:........................ 90

Turritellidse.................................................. . 92

Vermetidse........ ........................................... 92

Naticidse ..................................................... 93

Pyramidellidae. -..---.-...-..-....-.---.-----.--..-..--..-... 95

Nerineidse.............. ..-.-...-......-...-.-...-..-----...... __ 96

Cerithiidse .................................................... 99

Actaeonidae .......-...--....................--:..-...--........ 99

Cephalopoda...................................................... 100

Nautiloidea ............................ .:..-.-.-----....--... 100

Aniinonoidea ................................................. 101

Vertebrata ........................................................... 109

Index..... ........................................................... 169
ILLUSTRATIONS.

Page.

PLATE I. - - - Map of region near Sierra Bla,nca, Tex .................. 22

PLATES II-XXIX. Malone Jurassic invertebrates ..._......--....-...---. 114-168

LETTER OF TRANSMITTAL.

DEPARTMENT OF THE INTERIOR,

UNITED STATES GEOLOGICAL SURVEY, 

 Washington, D. C., February 4,1903. 

SIR : I transmit herewith, for publication as a bulletin of the Survey, a manuscript entitled " Paleontology of the Malone Jurassic 

Formation of Texas," by Francis Whittemore Cragin. Professor 

Cragin prepared a large part of this paper in 1.899, beginning the 

work while he was a graduate student in Johns Hopkins University, 

Baltimore, and continuing it here under my supervision in accordance 

with authority obtained from you at the time. I have inserted a 

sketch of the stratigraphy of the region and have prepared the accompanying map, using data furnished by Professor Cragin for the portion of the region referred to in his text.

I may add that Professor Cragin's collection of Malone fossils is 

now the property of the United States National Museum. 

Very respectfully,

T. W. STANTON, Paleontologist. 

Hon. CHARLES D. WALCOTT,

Director United States Geological Survey\

7

PALEONTOLOGY OF THE MALONE JURASSIC FORMATION OF TEXAS.

By F. W. CRAGIN.

SCOPE OF INVESTIGATION.

This paper embodies the paleontological and some geological results of recent studies in the Jurassic of El Paso County, Tex. It 

is in part the outgrowth of one of briefer scope, prepared in 1897-98 

from collections and data obtained by me in a reconnaissance made in 

1897, and supplemented by some of the results of the earlier work of 

'Messrs. Taff, Wyschetzki, and Goodell, as explained below. In its 

present form it includes also the study of two collections made by Dr. 

T. W. Stanton, of the United States Geological Survey, as noted more 

particularly elsewhere herein.

GEOGRAPHY OF THE REGION.

In El Paso County, a few miles north of the Rio Grande and 75 to 

80 miles southeast of El Paso, is a narrow ridge known as Malone 

Mountain. Its trend is nearly north-northwest and south-southeast, 

and is nearly continuous with that of the northwestern end of the 

Quitinan Mountains, from which'it is separated by an interval of less 

than a mile. At the eastern base of the mountain, near its northern 

end, on the joint line of the Southern Pacific and Texas Pacific railways is the flag station of Malone, which has an elevation of 4,262 

feet above sea level.0 Also on this line of railway, and between 2 and 

3 miles west of the north end of Malone Mountain, is Finlay station. 

As shown by the Fort Hancock sheet of the Topographic Atlas of the 

United States, in preparation by the United States Geological Survey, 

the mountain rises to somewhere over 5,050 feet above sea level, and so 

has a relative altitude of about 800 feet. On either side of the mountain ridge are hills that are geologically related to the mountain.

«Gannett, Henry, Dictionary of altitudes in the United States, third edition : Bull. 

U. S. Geol. Survey No. 160, 1899.
10 MALONE JURASSIC FOEMATION OF TEXAS. [BULL. 266. 

HISTORY OF GEOLOGICAL STUDIES.

The geological observations made along this part of the .Bio Grande 

Valley in the fifties by the-Mexican Boundary and Pacific Railway 

surveys were but cursory, and did not specifically include the Malone 

district, and the first serious geological study within the district was 

made in 1890 by the Geological Survey of Texas, under Mr. E. T. 

Dumble. In that year Mr. J. A. Taff, then attached to Mr. W. H. 

von Streeruwitz's Trans-Pecos division of that survey, studied Malone 

Mountain, and Mr. Ralph Wyschetzki, of the same division, collected 

a few fossils from the hills northeast of it. In the second annual 

report of the same survey, issued in 1891, Mr. Taff published and discussed a section of Malone Mountain and described, with scant allusion to its paleontology, an essential part of the Malone formation, 

consisting of limestone, gypsum, and flagstone of Malone Mountain, 

which he called the " Malone beds; " He thus virtually recognized 

the formation, his name for which, as the earliest proposed for it, is 

here retained; but he erred in placing it in the Washita Cretaceous 

division together with his Ethel en and Yucca beds, which are typically seen in a part of the Etholen Knobs and Yucca Mesa, and are of 

Glen Rose age. Mr. TafF also correlated the sandstone and oystershell breccia of the Etholen Knobs with the Malone formation, but 

these, like the Etholen breccia-conglomerates and the Yucca beds, belong to the Glen Rose alternating beds.

 In 1893 I described ° the better part of a small collection of fossils 

which Mr. Wyschetzki had obtained from the hills northeast of Malone Mountain. Disregarding for the moment a strong suspicion 

that these fossils were Jurassic, I described them as Cretaceous, 

since the time and material then available were too limited for a 

conclusive study, and since it was thought that the small Malone 

fauna then known had one species in common with the Cretaceous, in 

Trigonia taffii, which occurred \vith undoubted Cretaceous fossils on 

Bluff Mesa and was supposed to have been found in the Malone district also. 6 But I resolved to take up the question at the first 

opportunity that should offer.

a A contribution to the invertebrate paleontology of the' Texas Cretaceous: Fourth 

Ann. Kept. Geol. Survey Texas, pt. 2, pp. i-lv, 139-246, and Pis. XXIV-XLVI.

"The material thus treated included six new species, which were described under the 

following names : Anatina tosta, CucuUaia transpecosensis, Cyprina streeruvitzii, Trigonia 

vysclietzltii, Trigonia taffli, and Venus malonensis. It was afterwards found that Trigonia taffli does not occur at all in the Malone formation, but is a fossil of the Glen Rose 

alternating beds, to which Bluff Mesa belongs. The type material of Trigonia taffii was 

described (loc. cit., p. 214) as having come in part frpm Bluff Mesa and in part from the 

locality of Trigonia, vyscJietzkii, east of Malone. It is now, however, practically certain 

that the nearly complete valve fvom Bluff Mesa alone represented Trigonia taffli, and that 

all of the fragmental material which was supposed to belong to this species, and which 

was from the Malone locality, belonged as part of it which I recently had opportunity 

of reexamining certainly does to T. vysclictzkil. All of the very diligent collecting done 

at the Malone locality by Doctor Stanton and myself, while showing the occurrence of T.
HISTORY OF GEOLOGICAL STUDIES. 11

No opportunity for further investigation of the Malone fauna Avas 

presented until 1895. In March of that year the late Mr. -Robert W. 

Goodell, assisted by his father. Mr. R. R. Goodell, made a journey to 

Guaymas, Mexico, to obtain recent marine invertebrates from somerich collecting grounds on which I had worked in the winter of 

1882-83. In returning, he very kindly undertook to visit Sierra 

Blanca and Quitman mountains, Bluff and .other mesas, and. the 

hills north to east of Malone, to seek further evidence concerning 

the age of 'the rocks that had yielded the Wyschetzki collection. 

From the Sierra Blanca Mountains and several other of the elevations visited, which did not include Malone Mountain, the Messrs. 

Goodell brought back a large number of fossils, all of which were 

of the Comanche series save those from the hills a mile and a half 

east of Malone station. Those from the latter locality included, 

besides several of the species obtained there by Mr. Wyschetzki in

1890, some specimens which the Avriter recognized as specifically 

identical .with the Mexican Jurassic fossil, Pleuromya inconstans 

Castillo and Aguilera, and one example of an undescribed Trigonia 

of the Jurassic section- Undulata?. A restudy of Trigonia vyschet&kii, 

of which the Messrs. Goodell had obtained new material, led me to 

the conclusion that the affinities of that fossil also Avere Jurassic 

rather than Cretaceous. In 1896-97, therefore, I prepared a brief 

paper on the " Discovery of marine Jurassic rocks in southwestern 

Texas," assigning to the Malone. formation a stratigraphic place 

someAvhat different from that given to the original " Malone beds " 

of Mr. Taff, and announcing its Jurassic age. This article, Avhich 

included, from the field notes of Mr. Robert W. Goodell, the latter's 

section of the hills northeast of Malone station, Avas published in the 

Journal of Geology, Volume V, pages 813-820.

It was noted in this article that a comparison of the observations 

of Mr. Goodell with those of Mr. Taff seemed to show petrographical 

grounds for a formational correlation of the hills northeast of Malone 

station with the Malone beds of Malone Mountain. Such correlation, for a part of these hills and a part of the mountain, Avas confirmed paleontologically by me in August, 1897, Avhen I visited El

 vyschetzhii in profusion, has failed to yield a single fragment of the T. taffli. On the 

other hand the fauna with which T. taffii is associated was examined by Doctor Stanton 

and by me in 1897, both by a joint excursion to Bluff Mesa and by our independent 

examinations of the W. F. Cummins Red Bull Canyon collection in the museum of the 

Geological Survey of Texas, and was found to include, with some species hitherto undescribed, others of the Glen Rose Cretaceous.

In 1894 Mr. Cummins made a collection of fossils, including Trigonia taflii, near the 

southern end of the Quitman Mountains, labeling it "Mule Canyon." An excursion to 

Mule Canyon was made by Doctor Stanton and myself in 1897, but the fossiliferous rocks 

In its vicinity were found to contain Cretaceous fossils unlike those collected by Mr. 

Cummins. Further search by Doctor Stanton in' 1898 resulted in his discovering the 

locality of the Cummins collection, which was found to be Red Bull Canyon, the designation, " Mule Canyon," having been used by Mr. Cummins on his labels through some 

inadvertence.
MALONE JUKASSIC FORMATION OF TEXAS. [BULL. 266.

Paso County, Tex., and found that certain fossils were common to 

the locality a mile and a half east of Malone station and to the 

southeastern quarter of Malone Mountain, and in September of that 

year and in the summer of the jrear following, for the mountain in 

general and its western foothills, by Dr. T. W. Stanton, who found 

for these and the eastern foothills an essentially common fauna.

I arrived at Sierra Blanca station August 1.9, 1897, and remained 

till September 7, reconnoitering in several directions from that station as headquarters and giving the greater part of my time to the 

Malone district. I examined parts of the eastern slope of Malone 

Mountain, from which also I obtained a few fossils, and observed, 

from the southern part of the mountain crest, the general relations 

of the western foothills. But it was to the eastern hills, as including the locality that had yielded the interesting fossils to Mr. 

Wyschetzki and the Messrs. Goodell, that I gave chief attention; 

and from these hills I made a large collection of fossils. The western 

slope and foothills of the mountain I was unable to explore for lack 

of time.

On September 2 Doctor Stanton reached Sierra Blanca and joined 

me in exploring and collecting for a few days, both in Cretaceous 

localities and in the eastern part of the Malone district. Doctor 

Stanton remained in the field after my departure and carried reconnaissance further westAvard than I had, examining the western slope 

and foothills of Malone Mountain and making a section of the 

mountain. In the summer of 1898, with more time and better 

facilities at his disposal than had been available to either of us in 

1897, Doctor Stanton returned to this part of Texas and made additional collections and a comprehensive examination of the Malone 

and contiguous territory. Later, with the consent of the Director 

of the United States Geological Survey, Doctor Stanton very generously turned over to me for study and description all of the marine 

fossils collected by him from the Malorie formation in his two expeditions. Doctor Stanton's geological observations will Ue given by 

himself in another connection herewith.

The types collected in the Malone district by the Geological Survey 

of Texas in 1890 and described in the fourth annual report of that 

survey have in part been loaned to the United States Geological Survey by Doctor Dnmble and used in preparing this paper. Most of 

the species thus early collected are represented by ampler material 

from later collections. The more important of the specimens of the 

Goodell Malone collection, which were given to me by Mr. Robert W. 

Goodell in 1897, and my Malone collection, made in the latter year, 

have recently become the property of the United States National 

Museum and, first studied in the summer of 1898, have been restudied 

in connection with the other material. The material on Avhich these
CKAGIN.J GEOLOGY OP THE REGION. 13

paleonto.logi.cal studies are based therefore includes, with the exception of three or four mislaid specimens, all of the marine fossils that 

have hitherto been collected in Texas from rocks of the Malone 

formation.

GEOLOGY OF THE REGION.

All of the fossils described in this paper are from Malone Mountain and neighboring hills, and from within a few miles of the railway stations of Malone and Finlay. The greater number were 

obtained from east of the mountain, in the range of low hills which, 

in my article on " Discovery of marine Jurassic rocks in southwestern 

Texas," I called the Malone Hills.

Beginning about half a mile north of Malone station, and in part 

too low to be indicated by the contour lines, with 50-foot intervals, 

used in the general topographic'map of this region, these hills extend, 

trending at first about eastward and later more southeasterly, as a 

practically continuous Jurassic outcrop through the Neocene, for a 

distance of a mile and a half. At a mile to nearly a mile and a half 

from the station they include a line of three connected hills ((7, Z>, 

and E, on PL I, in order of distance from the station), which may 

be called the Trio. As best observed on the southeastern quarter of 

hill E, the Trio geological section comprises three natural subdivisions, the lower, middle, and upper of which respectively may be 

designated as Theta, Iota, and Kappa.

The Theta subdivision of this section consists chiefly of sandstone, 

with occasional courses of more or less sandy varying to relatively 

pure indurated limestone and some clay. The sandstone and clays 

are of a gray and yellowish-brown color, sometimes varying to purple and red. The purer of the limestone layers have a bluish-black 

color, weathering to gray or brown. Bedded and irregular seams of 

white cleavable calcite, sometimes several inches thick, here traverse 

the Theta in its upper part. The base of the Theta is not exposed.

A short distance southeast of hill E is a very low 'truncate mound 

(F), from which the Kappa subdivision had been removed by erosion 

before the prevalence of the Neocene waters which have so widely 

mantled the lower levels of this region with tufaceous cements and 

conglomerates. The mound is gently synclinal in structure and consists of a few feet of Iota conglomerates rising rather abruptly from 

gentle basal slopes. A Theta outcrop of only a few acres, hang chiefly 

in the interval between hill E and the Truncate mound, but extending 

also around the latter except on its east to southeast quarter, and 

embracing so much of the basal slopes of both elevations as has been 

denuoled of its Neocene mantle, is by far the richest collecting 

ground in the Malone district. This interval is of anticlinal structure, the strata increasing their dip from either the neighboring base
14 MAL01STE JURASSIC FORMATION OF TEXAS. [BULL. 266.

of the Trio or that of the Truncate mound toward a common line, 

the axis of a closed fold, where they stand nearly vertical, and \vhere 

is the shallow beginning of a small draw that deepens to the northward. This pinching and change of dip make difficult a close estimate of the thickness of upper Theta strata here exposed, but it does 

not seem probable that less than about 250 feet of these can have been 

involved in the exposed portion of either limb of the fold.

If we except obscure vestiges of fossils in the Kappa limestones 

and fragments of Paleozoic fossils (partly corals) in the pebbles of 

the Iota conglomerates, the fossils at this locality are confined to the 

Theta subdivision.

A very few forms, two or three of them identifiable as the commonest Malone species, were collected in the upper part of the Theta, 

chiefly in one bed of slight thickness, at a spot near the southwestern 

base of hill C, at the south border of the flat, saddle-like interval 

that separates the Trio from the west-northwestward continuation 

(A, B] of this hill range. In the immediate vicinity of this minor 

occurrence of fossils, and strati graphically lower, is a small exposure 

of gypsum. This locality is only about half a mile west and a little 

north of the principal collecting ground above described.

The Iota subdivision of the Trio section consists distinctively of 

coarse conglomerates, in six or more beds 1 to 8 feet thick, separated 

by layers of relatively soft sandstone. Many of the pebbles and 

cobbles in these conglomerates are of iron-stained chert and siliceous 

limestone; some are evident!}7 of Paleozoic derivation, and a few are 

of white quartz. In the southeastern slope of the east hill of the 

Trio the thickness of the Iota is about 50 feet. In the Truncate 

mound a considerable part of the original thickness has been removed. 

The dip of the Iota, like that of the other and generally much disturbed members of the Malone formation, is extremely variable in 

amount and direction. In the Trio and the Truncate mound it is 

usually from 15° to 25°, but exceeds the latter amount in places. On 

the southeastern slope of the Trio its direction is a few degrees west 

of north; in the east and west walls of the Truncate mound it is, 

respectively,' west and east.

At the isolated hill (G] south of the railway, between one-half and 

three-fourths of a mile southeast of the main fossil-bearing locality, 

no fossils were found, nor any Malone rocks lower than Iota, though 

the typical succession of conglomerates of the latter subdivision is 

shown there, blanketed by Neocene at its base.

The Kappa, which forms the upper portion of the Trio about 40 

feet in hill E is of hard, .massively bedded, bluish-black, calciteseamed limestone, charged with irregular segregations or impregnations of silica and iron. Much of it is cleft into large, rectangular
CJIAGIN.J GEOLOGY OF THE REGION. . 15

blocks by weathering along joint planes and bed planes in such a 

manner that it is not always very obvious which set of planes represents the dip except as this is indicated by underlying strata. It is 

impossible to say Avhat thickness it may have had here formerly, as 

an unknown part of it has been removed by erosion.

At its base in the Trio the Kappa limestone presents a zone several 

feet thick, composed almost Avholly of spherical, o'val, or somewhat 

irregular concretions, from 1 to 3 or 4 inches or occasionally more.in 

diameter. They consist of alternating lighter and darker layers, 

each a few millimeters thick, and sometimes weather uniformly with 

the matrix, being then seen in section, or are harder than the inclosing rock, when they are weathered out as pebbles, splitting sometimes 

into hemispheres which show the concentric layers. This is only an 

exaggerated sort of pisolitic structure. It is probable that this horizon, like others of the Malone formation, is variable, and that pisolitic structure is only locally developed in it. This rock is very 

probably similar to the pisolitic limestone conglomerate mentioned 

by Mr. TaiFas constituting No. 9'of his Malone Mountain "section.0

A reconnaissance was made of the western segment (A, B) of the 

Malone Hills, consisting chiefly of limestone and gypsum, with sandstone at its western end (as described by Mr. Eobert W. Gooclell in 

connection with his section of the Malone Hills) 6 and at least one 

remnant of conglomerate at its southern border; also of a ridge of 

quartzitic sandstone, apparently below the adjacent gypsum, and 

which forms an eastern foothill of Malone Mountain at the southern 

end of the mountain, and of portions of the eastern slope and summit of the mountain. But as these Avere for the most part only cursorily examined, and yielded no fossils except at one locality in the 

eastern slope of the mountain, no attempt will here be made to correlate positively their stratigraphic subdivisions with those observed 

at and southeast of the Trio.

i Provisionally, however, it may be said that if the gypsum near the 

southwestern base of hill G represents the same horizon as the heavy 

bed that traverses the western segment of the Malone Hills, and if the 

latter is but a reappearance of the great gypsum bed the upper limit 

of whose outcrop disappears by descending northerly from the southern east front of Malone Mountain, then the following inferences 

would apparently be reached:

(1) That the same gypsum, though not exposed there, probably

underlies the highly fossiliferous sandstones and limestones of the

Theta at the east end of the Trio and at the Truncate mound.

. (2) That the well-stratified limestones and the massive remnant of

conglomerate lying above this gypsum and bordering it on the south

."Second Ann. Kept. Geol. Survey Texas, pp. 722, 723. * Jour. Geol., vol. 5, p. 817.
16 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

in the western segment of the Malone Hills Avould represent the Theta 

and the Iota in that quarter.

(3) That the conglomerates above the gypsum in the east face of 

Malone Mountain, at the southern end of the mountain and at the 

transverse anticline a mile farther north, would represent, in part at 

least, the Iota.

(4) That the Theta in the eastern slope of the mountain at its 

southern end would, if present, belong about at'the summit of the 

gypsum, and that it either has been removed by erosion during the 

formation of the conglomerates or is possibly represented there by 

the upper part of the gypsum itself.

The fossils obtained by me from the eastern slope of the mountain 

were found in a ravine at the base of the mountain, in a horizon of 

impure limestone, at the passage from conglomerates like those of the 

Iota to limestones like those of the.Kappa, forming part of an 

obliquely transverse anticline about a mile north of the southern end 

of the mountain; those collected at the latter locality by Doctor Stanton were obtained in part from limestones somewhat higher in the 

anticline.

DISTRIBUTION OF FOSSILS IN MALONE DISTRICT.

A large number of the fossils herein described will be found 

recorded as having been collected by Doctor Stanton at a number of 

points on or near Malone Mountain, especially on the western slope 

and foothills. The great majority of these had previously been found 

at the notable locality east of Malone, but several will be found listed 

from the mountain or its western foothills only. Among these arc 

the Nautilus, a few other Mollusca, and the two echiiioderms.

How prolific the Malone formation is in fossils at the several collecting stations, and how much the original Malone Hills locality 

excels the others, may be seen by the following lists:

OCCUKRENCE OF SPECIES BY LOCALITIES.

LOCALITY No. 1. Theta subdivision of the Trio section in the Malone Hills, li 

miles east of Malone railway station.

Astrocoenia maloniana. Plicatula sportella.

Serpula gorclialis. Lima (Raclula) interlineata.

Serpula sp. (large). Lima (Ctenostreon) riograndensis. 

Serpula sp. (small, with annular, fili- Pec-ten insutus.

form costellae). Gervillia corrugata.

Berenicea maloniana. Mytilus nuntius.

Ostrea sp. Modiola maloniana.

Gryphfea mexicana. Pinna quadrifrons.

Exogyra subplicifera. Area? dunibli.
CBAGIN.] DISTRIBUTION OF FOSSILS. 17

Arcaltaffii.

Cucullifia catorcensis. 

Cucullasa texticostata. 

Cucullsea transpecosensis. 

Leda? uavicnla?. 

Trigonia calderoni. 

Trigonia conferticostata. 

Trigonia goodellii. 

Trigonia inunita. 

Trigonia proscabra. 

Trigonia rudicostata. 

Trigonia vyschetzkii. 

Astarte? craticula. 

Astarte? isodontoides. 

Astarte inaloneusis. 

Astarte niicrophyes. 

Astarte posticalva. 

Ptychomya stantoni. 

Lncina? uiexicana. 

Luciua potosina. 

Lucina potosina, var. metrica. 

Unicardiuin semirotunduni. 

Unicardium transversuin. 

Cyprina coteroi. 

Cyprina? streeruvitzii. 

Tapes? cuueovatus. 

Pholadomya marcoui. 

Pholadornya paucicosta. 

Pholadomya prseposita. 

Pholadomya tosta. 

Pleuromya inconstans.

,Pleuroinya inconstans, var. curta. 

Anatina obliquiplicata. 

Anatina pliculifera. 

Thracia? maloniana. 

Martesia? maloniaua. 

Pleurotomaria circumtruuca. 

Turbo? beueclathratus. 

Delphinula stantoui. 

Nerita nodilirata. 

Nerita peroblata. 

Vermetus cornejoi. 

Natica bilabiata. 

Natica inflecta. 

Natica williamsi. 

Cheiunitzia goodellii. 

Nerinea circuuivoluta. 

Nerinea goodellii. 

Nerinella stantom.

Cerithium arcuiferum. 

Actajonina? maloniana. 

Oppelia? fallax. 

Olcostephanus lualouianus. 

Perisphiuctes felixi. 

Perisphinctes potosinus. 

Perisphinctes schucherti?. 

Aspidoceras alamitocensis. 

Pycnodont fish tooth. 

Cycloid fish scales.

Enaliosaur (fragments of bones, indicating animal of considerable size).

LOCALITY No. 2. South border of flM saddle, west of. the Trio, about a mile east 

of the Malone railway station.

Trigonia vyschetzkii. 

Astarte nialouensis.

Pleuromya inconstans?.

LOCALITY No. 3. Anticline in east slope of Malone Mountain, about a mile north

of the southern end.

Holectypns? sp.

Serpula gordialis.

Gryphrea mexicana.

Exogyra subplicifera (probable casts

of).

Modiola maloniana. 

Cucnllaea catorcensis. 

Leda? navicula. 

Astarte malonensis.

Un icardium seni irotunduru. 

Unicardium transversum. 

Plenromya inconstaus. 

Martesia maloniana. 

Turritella burkarti. 

Chemnitzia goodellii?. 

Nerinella stantoni.

Selachian (fin spine of indeterminate 

genus).

Bull. 266 05 M-
18 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

LOCALITY No. 4. About a mile a east of the railway station of Finlay; apparently 

about the same horizon as the locality next below mentioned.

Gryphsea mexicaua. Trigouia proscabra?.& 

Lima interlineata.. Astarte malonensis. 

Pecten insutus. Unicarclium transversum. 

Modiola geniculata. Chemnitzia gooclellii. 

Modiola inaloniana. Nerinella stantoni. 

Trigouia calderoni.

LOCALITY No. 5. Foothills near the railroad, at northwestern end of Malone 

Mountain, a, little over 2 miles east-southeast of Finlay station, not more than 

200 feet above the gypsum bed; total exposure above gypsum bed here 540 

feet; fossils all from middle hundred feet.

Cucullsea castilloi. Natica finlayensis. 

Lucina potosina, var. metrica. Natica inflecta. 

Lucina planiuscnla. Nautilus nauf.ragas. 

Unicarclium semirotundum. Oppelia fallax?. 

Pboladoruya paucicosta. Perispbinctes scbucherti. 

Nerita finlayensis.

LOCALITY No. 6. First high ridge west of M alone Mountain, about 2 miles west 

of M alone station, in No. 13 of Doctor Stanton's M alone Mountain section.

Grypluea mexicana. Astarte malonensis. 

Pecteu insutus. Pleuromya iuconstans. 

Trigonia munita. «

LOCALITY No. 7. West of the north part of M alone Mountain,- about 2 miles 

southwest of Malone station, in No. 13 of Doctor Stanton's M alone Mountain 

section.

Grypbaea mexicana. . Martesia maloniana.

Pecten insutus. Chemnitzia gpodellii.

Astarte malonensis. Nerinella stantoni.

Unicarclium semirotundum. Nautilus burkarti?.

Pleuromya inconstans. Perispbinctes clarki.

LOCALITY No. 8. At same locality as the preceding, but from a horizon 220 feet 

higher, viz, No. 25 of Doctor Stanton's Malone Mountain section.

Pygurus sp. . Pinna quadrifrons. 

Grypbaea mexicana. Pleuromya inconstans.

LOCALITY No. 9. West base of Malone Mountain, a short distance north of the

southern end.°

Gryphsea mexicana. Pinna quadrifrons.

Exogyra potosina (broadly triangular Pboladomya cf. marcoui.

phase). Pleuromya inconstans.

Gervillia Cinderella. Pleuromya inconstans, var. curta.

Gervillia? riograndensis. Corbula? maloniana.

" Something more than this distance, a little south of east.

6 A cast; it may possibly represent T. prwstriata. .

c On this collecting station, having previously referred In his field notes to a freshwater limestone 75 to 100 feet below a quartzitic conglomerate at top of Malone Mountain a short distance north of its southern end,'Doctor Stanton comments as follows: 

"In the field this was believed to be between the fresh-water horizon and. the quartzitic 

conglomerate above mentioned. It is certainly several hundred feet above a horizon of 

the GryplKB mexicana and Nerinea."
CRAG IN.] AGE OF MALONE FAUNA. 19

LOCALITY No. 10. Foothill west of Malone Mountain, about 2 miles north of its 

southern end; possibly same horizon as that of the preceding locality.

Gryphsea mexicana. Astarte rualonensis?.

Exogyra potosina (narrower phase). Lucina potosina, var. metrica.

Pecten insutus. Pleurornya inconstans.

Pinna quadrifrons. Perisphinctes aguilerai..

LOCALITY No. 11. Near southern end of Malone Mountain, west face, near top; 

. strati graphic relation obscure.

Trigonia inunita. Neriuea goodellii.

LOCALITY No. 12. Conglomerate on toest face and near top of Malone Mountain.

Trigonia goodellii? (cast, larger tban other specimens of this sp.)

LOCALITY No. 13. East slope of Malone Mountain near the southern end; 200 

or 300? feet above the gypsum.

Gryphtea mexicana. Oppelia fallax?. 

Trigonia prsestriata. Perisphimetes clarki.,

AGE OF'MALONE FAUNA.

The affinities of its fauna clearly refer the Malone formation to 

the Jurassic. The .only evidence that at first thought might seem 

discordant is the occurrence of the genus Ptychomya, which, with one 

or tAvo doubtful exceptions, has not been recorded hitherto from rocks 

older than the Cretaceous. But when it is remembered that, of the 

Cretaceous Ptychomyas, only one species occurs later than the Lower 

Cretaceous (Neocomian and Gault) and that this one, the Pt. zitteli 

of the western Alps, is from the Turonian, no species occurring in the 

higher (Senonian and Danian) stages of the Cretaceous, the occurrence of one or two species of Ptychomya in the upper part of the 

Jurassic is only that Avhich it would be reasonable to anticipate. 

This genus occurs at Chilian, Chile, in rocks of debatable age, and it 

is thought by Doctor Steinmann to have been derived there possibly 

from the same bed that yielded his Trigonia transitoria, from which 

T. vysclietzldi is scarcely distinguishable. The T. transitoria occurs 

also at Caracoles, Bolivia, where, on the basis of the kind of rock 

attached to the specimen, Doctor Steinmann supposes it to hail from 

the Lower Cretaceous; but nearly all of the Mesozoic fossils that he 

lists from Caracoles he considers Jurassic.

The sections Undulatce and Costatce, to which several of the Malone 

Trigonias belong, are exclusively Jurassic," and, if we except Tri-

«By Pictet and Campiche (.Pal. Snisse; Terr.. Cret. de St. Croix, p. 360. 1866) and 

Stoliczka (Pal. Indica; Cret. Fauna S. Ind., vol. 3, p. 311. 1871), the section UnduIqtte is said to include some Cretaceous species, but by later authorities it is cited as 

exclusively Jurassic. Thus it occurs, according to Zittel's Handbuch (1881-1885) " Nur 

In Jura; " and according to Steinmann and DOderlein's Elemente (1890), ".Oberer Lias 

Oberer Malm."
20 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

gonia prcestriata represented by a single somewhat imperfect 

mold none of the Malone Trigonias agree perfectly with generic 

sections hitherto known from Cretaceous rocks, exclusively.a The 

genus Trigonia is moreover generally considered one of the best of 

the Lamellibranch genera for purposes of stratigraphic diagnosis.

But it is to the ammonites that we must look for the strongest 

evidence of geologic age, these being generally regarded as the most 

critical of molluscan fossils as guides to stratigraphic correlation. 

And here, too, the evidence is clearly conclusive of Jurassic age. 

Though several of the genera are common to the Jurassic and Cretaceous systems, all of the known European analogues in species and 

subgeneric groups are Jurassic. The ammonitic genus of most frequent occurrence in the Malone is Perisphinctes, which is common 

to the two systems, but is almost exclusively Jurassic. Of the 366 

known species of this genus b only four, described by Neumayr and 

Uhlig from the upper Neocomian of Saltzgitter,0 are Cretaceous; 

and these belong to a group'which the Perisphinctes species of the 

Malone formation do not at all approach. On the contrary, the 

species of Perisphinctes to which those of Malone show the closest 

affinities are those of the Tithonian.

It should be noted that while some of the molluscan .fossils other 

than ammonites seem to indicate Kimmeridgian, or earlier than 

Tithonian age, this is more or less offset by the presence of the ordinarily Cretaceous genus Ptychomya.

LOCALITIES Or RELATED FAUNAS.

The only localities which present rocks known to correspond more 

or less closely with those of the Malone formation are in Mexico.

In the descriptive part of this paper it is noted that some of the 

fossils of the Malone formation are identical, with some of those of 

the Alamitos beds, described by Castillo and Aguilera as occurring 

at the Sierra de Catorce in San Luis Potosi, and that others agree 

with species described by Doctor Felix from the Cerro de Titania in 

.Oaxaca. The number of forms at present known to be common to 

the Malone and the Alamitos is so considerable that there can be 

little doubt that these two names represent approximately the same 

horizon. The ammonites of the Alamitos, like those of the Malone,

&

are of Titonian affinities.

0 Doctor Stanton, however, places Trigonia proscabra in the Scabrse, and questions 

whether T. calderoni be not referable to that section also rather than to the Undulate.

"In the body of his recent Monograph of Perisphinctes, Siemiradzki treats 363 species 

 of this genus. In its supplement, of a large number of additional alleged new species 

cited as described" by De Rias and Tornquist in 1898, he identifies ail but three with 

species previously known, so that the number of species recognized by. Siemiradzki in 

the early part of 1809 was -366.

" Ueber Ammoniten aus den Hilsbildungen Norddeutschlands; Paleontographica, Bd. 

XXVII, 1881. -
CRAGIN.] LOCALITIES OP BELATED FAUNAS. 21

The number of fossils known from the Jurassic of the Cerro de 

Titania is small, but indicates, so far as i't 'goes, a position high in 

the upper Jurassic series, as shown by Doctor Felix; and it is at 

least worthy of note that of the few lamellibranchs known front 

these rocks, Exogyra subplicifera and Gryphcea mexicana occur 

also at Malone, Astarte microphyes may be the same as A. brexiacola, 

and the large Trigonia sologureni, known only from the cast, may yet 

prove to be identical with the Malone species, T. vyschetzMi, when the 

details of its shell come to light.

Besides the Malone district, the Sierra de Catorce, and the Cerro 

de Titania, several other localities in Mexico have yielded fossils-of 

the Malone formation. Thus a Perisphinctes, supposed to be related 

to the European P. balderus, is apparently common to the Theta and 

the Alamitos and is reported from Tutotepec also, in the State of 

Puebla, by Castillo and Aguilera; and by the same writers Perisphinctes mazqpilensis and Haploceras mazapilensis are recorded 

from the Alamitos and from the Sierra de Zuloaga, in Zacatecas.

A number of Mexican Jurassic localities besides those here mentioned are given in Aguilera's " Sinopsis de Geologia Mexicaha;"° 

but these are little known, and at some of them the rocks belong, at 

least in part, to the lower Jurassic. It is, however, interesting to 

note that the Jurassic district of Malone is in the continuation of the 

belt along which are scattered all or nearly all of the Jurassic tracts 

shown on the geological map of Mexico of 189T published with Nos. 

4-6 of the Boletin del Institute Geologico de Mexico.

It is not improbable that rocks nearly related to the Malone occur 

in .South America. As , shown in the discussion of that species, 

Trigonia vyschetzkii is very close to the Andean form, T. transitori.a 

Steinmann, a species whose precise geological position has hitherto 

been doubtful, but which the evidence from the Malone district tends 

to show probably belongs to the upper Jurassic.

ACKNOWLEDGMENTS.

I wish to acknowledge my indebtedness to all of those mentioned 

elsewhere herein as having contributed directly or indirectly to the 

success of this study. The kind services of the Messrs. Goodell were 

of especial value, as furnishing the first fairly conclusive indication 

of the Jurassic age of the Malone formation. To the Hon. Charles 

D. Walcott, Director of the United States Geological Survey, and 

to Mr. Charles Schuchert, Curator of Invertebrate Paleontology in 

the United States National Museum, I am indebted for important 

aid. I am under obligations also to Mr. John N. Gilcrease, Mr.

0 In Bosquejo, Geologia de Mexico: Boletin del Institute Geologico de Mexico, Nos. 

4-G, pp. 187-250.
22 MALONE JURASSIC FORMATION OP TEXAS. [BULL. 2«ft

Charles M. Wilson, and Mr. John W. Williams for favors rendered 

while I made headquarters at Sierra Blanca, and particularly to 

Mr. Williams, who showed much interest in the Malone investigation, assisted in collecting, and facilitated the field work in every 

possible way, contributing in no small measure to its success. I deem 

it but simple justice to Doctor Stanton, and at the same time a pleasure, to state that I OAve very much indeed to his full and generous 

cooperation in promoting every desired use of the collections under 

his charge, and in holding at my service a splendid knowledge of 

Mesozoic conchology and its literature and methods. And, finally, it 

is- also due to Prof. William Bullock Clark, head of the geological 

department' of Johns Hopkins University, to add that without his 

efficient planning of it as a whole, this contribution to American 

Jur-assic paleontology could have been undertaken at this time, if at 

all, only under far greater limitations, both as to scope and as to 

facilities for research.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. I

INCLUDING PORTIONS OF FORT HANCOCK, SIERRA BLANCA 

AND EAGLE MOUNTAIN QUADRANGGES 

Scale

Note: Localities of Jurassic fossils are designated by numberi 

as in the text

The sections described and the minor topographic 

features mentioned in the text are also located
STRATIGBAPHIC NOTES ON MALONE MODNTATN 

AND THE SURROUNDING REGION NEAR SIERRA 

BLANCA, TEL

y T. W. STANTON.

GENERAL REMARKS.

It has been deemed advisable to supplement Professor Cragin's 

paleontological paper by a brief account of the general geology of 

the region in which his Jurassic fauna occurs. The data here presented were obtained in 1897 and 1898 during two reconnaissance trips 

undertaken for the purpose of unraveling the obscure Cretaceous 

section of the Sierra Blanca region and, if possible, of determining 

the stratigraphic relations of the Malone Jurassic with the Cretaceous, as well as of making collections from all of the fossiliferous 

horizons of the region. The stratigraphy of the Cretaceous was 

determined fairly well, several fossiliferous horizons in the Jurassic 

of Malone Mountain were established, and interesting collections of 

fossils were obtained from both the Cretaceous and the Jurassic, but 

the rocks of the two systeips were not found associated in the same 

continuous section, and their stratigraphic relations were not definitely determined.

In 1897 two weeks Avere spent at Sierra Blanca station examining 

the outcrops within a few miles of that station and one excursion 

was made 25 miles southward, to the Rio Grande. In 1898 a month 

was spent in the region working with a wagon and camp outfit, but 

even then many points could not be conveniently reached nor thoroughly studied because, on account of the scarcity of water and of 

roads, camping places were limited in number. The area examined 

comprises parts of the Fort Hancock, Sierra Blanca, and Eagle 

Mountain quadrangles, as mapped by the United States Geological 

Survey, extending from the Finlay Mountains on the north to the 

Eio Grande on the south and from .the western foothills of Malone 

and Quitman mountains to Devils Ridge and Eagle Mountain on the

east.

23
4 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

The region as a whole is characterized by rugged hills, ridges, and 

mountain masses rising abruptly from broad yalley plains which are 

filled to an unknown depth with coarse Tertiary (?) deposits that 

obscure the structure of the older rocks beneath them. The general 

strike of the uplifted strata is northwest and almost all the smaller 

hills and ridges are monoclinal, with beds generally dipping southwest. In describing the Cretaceous deposits of this region in 1891, 

Mr. J. A. Taff 0 thought that the beds exposed north of the Sierra 

Blanca station are the oldest and that successively newer beds are 

found to the southwest except that there is some repetition by faulting. This opinion was based on the general posture and geographic 

. relations of the "beds and on the lithologic similarity of certain conglomerates and limestones in the Jurassic and the Cretaceous. The 

characteristics of the faunas involved were then practically unknown. 

It will be shown, however, that the real succession of strata is very 

different from that given in Mr. Taff's published section, the oldest 

Mesozoic rocks being found in Malone Mountain. Mr. Taff briefly 

discussed the folding and faulting that is common throughout the 

region and that is doubtless often present under the debris of the valle}^s as well as in the mountain masses. It would require much more 

time and study than has yet been given to this area to work out all 

its details of structure, which is further complicated by many intrusive masses of igneous rock in all the larger uplifts except Malone 

Mountain.

MALONE MOUNTAIN AND THE JURASSIC.

The strata bearing the Jurassic fauna described by Professor Cragin have been found only in Malone Mountain and the adjacent 

valleys.. The Malone Mountain uplift extends from the Southern 

Pacific Railway near Finlay station about 5 miles in a southeasterly 

direction and ends abruptly a few hundred yards from the northwesterly extremity of the Quitman Mountains. Malone station, 

"which is 13 miles by rail from Sierra Blanca station, is at its eastern 

base a little north of the middle. From this direction the mountain 

looks like a simple unbroken ridge, but on the southwest side it is 

deeply dissected by both transverse and longitudinal valleys.

The general structure seems to consist of a syncline along or east 

of the crest of the principal ridge, with an anticline in the valley and 

subordinate ridges of the west slope. There are also several minor 

folds, often beautifully shown, and doubtless some faulting. Toward 

the southern end of the mountain a small anticline is developed on 

the eastern slope. Mr. Taff has published a figure of the Malone 

Mountain section l showing these general structural features. He has

o Second Ann. Kept. Geol. Survey Texas, pp. 714-738. * Idem, PI. XXVII.
STANTON.] MALONE MOUNTAIN AND THE JURASSIC. '25

also described 0 the succession of strata in the middle section of the 

mountain, which agree in the main with my observations, though 

both structure and exposures vary greatly in different parts of the 

uplift.

The most complete section that I observed, in which the thicknesses 

were estimated with s'ome care, extends across the mountain from a 

point on the east side about .one-half mile south of Malone station. 

The eastern face of the mountain shows an apparent thickness of 

about 1,200 feet of blue and gray limestones, with a few intercalated beds and bands of conglomerate and sandstone, the beds all 

dipping strongly westward with increasing dips until they become 

vertical on the crest. On the west slope there is a succession of limestones, conglomerates, and gypsum beds, nearly vertical and not well 

exposed, and farther down these are apparently repeated with awesterly dip, overlain by conglomerates, limestones, etc., fairly well 

exposed and not much disturbed in the lower ridges to the west. 

The gypsum beds" and the limestones immediately associated with 

them appear to be the oldest rocks exposed. The following section 

begins with what Avas supposed to be the lowest gypsum bed, but on 

account of complex structure and obscure exposures the succession 

and thickness of the first five members are somewhat uncertain.

Section of Jurassic beds on ivest side of Malone Mountain, near Malone station

(Section I of map).

	Feet.

1. Gypsum, not well exposed, about ._____-_________ 100

2. Calcareous conglomerate, almost vertical_______________.___-_ 45

3. Mostly covered; limestone below, gypsum above (dip variable, westward), about ___.__________..____ _____________ 200

4. Altered and fissured limestone_____-__________ _ _ 125

5. Gypsum, not well exposed---_____<_____________ 100

0. Siliceo-calcareous shale ________________ ____._________ 40

7. Limestone _-_-__-____ - - - - _-__-_---_- 20

8. Covered (sbale?) ___._'___:_____________________-_ 300

9. Blue limestone, witb traces of fossils . -~__1____- _______ . 2

30. Covered __________________ ____________ _ 15

11. Arenaceous limestone ____ _ _ _ _ - _ _______-.__-_ 1

12. Covered __.__.______ _______________._____.__________. 10

13. Blue limestone, with the Malone fauna___ _____ ____ _ _ __ 2

14. Covered_______________________________ ___ 10

15. Limestone-----___-- - -- - - -- --- 1

.16. Covered_________________ - 8

17. Thin-bedded limestone and shales______ __: _ 20

18. Calcareous conglomerate ___ _ --__. 15

19. Limestone with Pleuromya and Gryphrea _ _ 15

20. Covered________________-_ 10

21. Calcareous conglomerate _ _ _ _l ______ 15

a Idem, pp. 722-723.
26 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

Feet.

22. Limestone with fragmentary fossils (Ammonites, etc.)_________ 10

23. Calcareous conglomerate_____________________________ 15

24. Covered __________________________ __________ 100 

~5. Limestone with Gryphsea, Pinna, Trigonia, etc__.___________ 15

2G. Covered in talus slope_____________________________ 150

27. Thin-bedded brown sandstone with bands of conglomerate and containing a small Ostrea, Nerinea, and a few other fossils, poorly 

preserved _______________________________ 25

28. Massive, gray, calcareous sandstone______________.____._____ 10

29. Gray limestone forming a prominent ridge.________________ ±250

?>0. Brown conglomerate, composed mostly of quartzite and chert pebblesj 40 

31. Blue limestone____________________________ 100

This is uncpmformably overlain by the unconsolidated Tertiary or 

Pleistocene conglomerates of the plains on the west.

The main ridge of Malone Mountain on the, line of this section 

seems to be made up of Nos. 29, 30, and 31, with perhaps some higher 

beds, all repeated by the synclinal fold.

Nos. 13 and 25 each yielded fossils, some of which are specifically 

identical with forms occurring at Professor^ Cragin's principal 

locality for the Malone Jurassic fauna, and the fossils mentioned 

in other bands (Nos. 9, 19, 22, and 27) evidently belong to the same 

fauna.

Some bands in the limestone No. 29 yielded a few fossils that 

seem to be fresh-water forms small, simple gasteropods, resembling 

Viviparus. Similar forms were seen in No. 31 also.

Near the south end of Malone Mountain the same horizon in 

No. 29 yielded some small bivalves with the external features of Unio 

associated with the gasteropods. Conglomerate No. 30 of the section, 

however, contains marine fossils, including Ammonites, Exogyra, 

and several other genera. These were not found on the line of the 

section above described, but the conglomerate is a prominent, easily 

recognized horizon exposed at many points along the entire length of 

the mountain, and the fossils, usually in the form of imprints and 

fragments, Avere seen at several places both north and south of the section, especially toward the southern end of the mountain. In the 

western foothills of the mountain, 1 to 2 miles north of the southern 

end, there are exposures of a conglomerate believed to be the same as 

No. 30, and in the uppermost bands of the limestone immediately 

beneath it collections were obtained containing Exogyra, Pinna, 

Pecten, Pleuromya, Perisphinctes, etc., which Professor .Crag.in has 

assigned to the Malone fauna (see p. 19).

At the end of the northwest spur of Malone Mountain, at the point 

where it approaches the railroad, there are large exposures of gypsum 

that almost certainly belong to the gypsiferous horizons in the section just described, though they are separated from them by struc-
STANTON.] MALONE MOUNTAIN AND THE JURASSIC. 27

tural"breaks.0 In the following section the estimated thicknesses of 

the gypsum and the beds overlying are not closely accurate, because 

the exposures are very incomplete and the dips are variable and not 

easily determined.

Section near north-west end of Malone Mountain abO'iit 2 miles southeast of 

Firilay station (Section 11 of map).

Feet.

1. Gypsum__________________.____- ________ 100 or more.

2. Mostly covered about_________________________ 200

3. Limestones with conglomerate layers alternating with softer 

shaly bands. Several fossil if erons horizons with Malone 

fauna (see lists, p. IS)______________i______ 75

4. Limestones passing into calcareous conglomerate___-______ .1.5

5. Limestone with a few Malone fossils_________ _______ 15

G. Calcareous conglomerate__.___-__.,________-_________ 6

7. Covered (shales and limestone)_______________ __ 20

8. Calcareous conglomerate---___________-_______ 10

9. Blue limestone dipping 20° SW., with echinoids and large

Nerinea. seen in section on weathered surface_____._____ 6

10. .Blue limestone and shale passing under the plain__________ 200

There can be little doubt that the fossiliferous beds in this section 

are on very nearly the same horizons as those in the section Avest of 

Malone station.

The most prolific locality for Malone Jurassic fossils, and the only 

one not directly connected with the mountain itself, is in the low 

hills in the valley about 1-| miles east of Malone station. The 

exposures are comparatively small and the dips variable, so that the 

stratigraphic details either as to thickness or succession can not be 

determined Avith certainty. Professor Cragin gives his observations 

on this locality fully in another place (pp. 13-17).

It is not possible to make a definite correlation of the fossiliferous 

beds here with any single horizon in the Malone Mountain sections, 

but it is most probable that they belong not more than 300 feet 

above the main gypsum beds.

At this point the Malone Jurassic beds are closer to fossiliferous 

Cretaceous beds of determined horizon than at any other place 

observed in the region. About 3 miles to the east, near the southwest base of Sierra Blanca, there are exposures of Washita beds with 

Nodosaria texana and Gryphcea mueronata (?), and the same horizon occurs a little farther away along the railroad between Etholen 

Hills and Quitman Mountains.

Mr. Taff correlated portions of the Malone Mountain section with 

exposures-in the conical hills near Etholen about'5 miles Avest of

" Mr. Taffi assigned these gypsum exposures, as well as those at the southeast end of the 

mountain, to a higher horizon (see pp. 725 and 736 of his report), hut they all have the 

same relations to the fossiliferous horizon bearing the Malone fauna.
28 i MALONE JURASSIC FORMATION OP TEXAS. [BULL. 266.

Sierra Blanca station, and in Bluff and Yucca mesas near the same 

station, but I was unable to confirm these correlations. The strata 

in the " Etholen Knobs " may possibly belong here, but the other 

localities almost certainly show only Cretaceous beds.

THE CRETACEOUS.

Cretaceous rocks have a great development in this region and 

represent the three main divisions of the Comanche series the 

Trinity, Fredericksburg, and Washita as well as a part of the 

Upper Cretaceous. Lithologically the section differs greatly from 

that of Central Texas, where the Comanche series has been most 

studied, and there are also considerable differences in the vertical 

range of some of the common species, so that it is impracticable to 

recognize many of the minor formations and horizons that have 

been studied. The general faunal succession is the same in both 

regions, and it is usually not difficult to classify the beds by means 

of the fossils as Trinity, Fredericksburg,. or Washita, though it was 

difficult and sometimes impossible to assign each exposure to its 

exact position in the general section, because many of them are relatively small and isolated, and the structure is complicated by folds, 

faults, and igneous intrusions. The most complete sections are to 

be found in the Quitman Mountains, especially toward the southern 

end and in the lower hills farther south on the Rio Grande, in the 

southern extension of the same line of uplift.

Quitman Mountains. This range begins at a point on the railroad 

8 miles west of Sierra Blanca station and extends in a southeasterly 

direction about 25 miles, the uplifted beds continuing as low ridges in 

the same direction and crossing the Rio Grande 6 or 7 miles beyond 

the end of the main range. At its northern end it is composed mainly 

of igneous rocks granites' and porphyries with Cretaceous beds in 

the adjacent foothills on the north and east, but south of Quitman 

Canyon, a drainage channel that cuts straight across the range about 

10 miles south of its northern end, the mountain mass is-composed of 

Cretaceous sediments, with only occasional igneous intrusions. The 

axis of the range is for a number of miles almost parallel with the Rio 

Grande, which flows about 6 miles to the southwest, while on the other 

side is the flat valley of Quitman Arroyo, 4 to 10 miles wide, separating the Quitman Mountains from Devils Ridge and Eagle Mountains. 

Sections taken at different points across this range vary greatly in 

extent. The one published by Taff in the report cited was taken 

near Quitman Canyon (Section III of map), and shows the strata 

with variable steep dips mostly to the west, but sometimes reversed. 

Near the eastern end of the section is a heavy bed of limestone, forming part of Taff's " Bluff bed," filled with Orbitolina texana and a
STANTON.] THE CRETACEOUS. . 29

few other forms, followed by a band of hard limestone containing 

numerous specimens of Requienia. Then comes the " Quitman bed," 

composed of sandstones, clays, and thin beds of limestone, with a 

thickness of 330 feet, succeeded on the west by a great series of sandstones and. siliceous limestones, the " Mountain bed," with an apparent thickness of about 4,000 feet. The western end of the section, 

was thought to be the top, and the entire section was referred to thi 

Washita division of the Comanche series. My studies of more complete sections farther south in the same range, especially the one near 

the Kio Grancle, led to the conclusion that the beds at Quitman Canyon and for a long distance southward are mostly overturned, and 

that the oldest rocks are on the west side of the mountains.

The Mountain bed, consisting mostly of coarse, varicolored sandstones, forms the western portion of the mountain all the way to the 

Rio Grande at Hot Springs, where it dips to the east instead of to the 

west. Its apparent great thickness may be due in part to folding and 

faulting. It has .yielded only imperfectly preserved Ostrea and a feAv 

other forms that are insufficient for its-correlation with established 

formations.

The Quitman bed has a similar distribution along the higher (western) slope of Quitman Mountain. Its fauna shows a different facies 

from any assemblage in the Central Texan section, including Exogyra 

quitmanensis,Trigonia taffii, Trigonia stolleyi .(1}. Remondia, and a 

considerable number of forms that will be described in a monograph 

of the Comanche fauna." Although some' of the species show relationship with later faunas the stratigraphic and paleontologic evidence as a whole is thought to justify its assignment to the Trinity 

division. The best localities found for collecting this fauna are on 

Quitman Mountain about 1 mile south of Quitman Canyon, and on 

the trail from Quitman Arroyo to Hot Springs, about 3£ miles from 

the springs.

The Orbitolina limestone for many miles forms the crest of the 

Quitman Mountains, with a bold escarpment on the east and a steep 

slope corresponding with the dip on the west. Its characteristic 

fora-minifera, Orbitolina texana (Roemer), occurs only in the Glen 

Rose beds of the Trinity division in Central Texas. Another species, 

of the same horizon that occurs with it in the Quitman Mountains is 

the large iVatiea prcBgrandis Roemer, which is usually treated as a 

synonym of N. pedernalis. The Orbitolina limestone has here a 

thickness of at least 250 feet, and farther south on the Rio Grande it 

appears to be still thicker, and the Orbitolina again appears in a 

thinner limestone about 300 feet higher.

On the eastern slope of the mountain 1 to 2 miles south of Quitman 

Canyon there are exposures of several hundred feet of limestones, 

clays, and sandstones dipping toward the mountain and apparently
30 MALO-NE JURASSIC FORMATION OF TEXAS. [BOLL. 266.

underlying the Orbitolina limestone (Section IV of map). The succession from the Orbitolina limestone eastward down the mountain 

is as follows:

Feet.

1. Alternating thin beds of sandstone and clay, with occasional bands of

limestone; Exogyra texana near the middle.________ _ _ 200

2. Alternations of limestone and covered spaces_____________ 200

3. Sandstone_______________________________________ 8

4. Covered_____________________________________ 15

5. Sandstone with Actwonella dolium_______________________ 15

0. Argillaceous limestones, clays, and some arenaceous bauds, with occasional layers containing Exogyra texana______________- 300

7. Limestone in several massive beds interstratified with more or less ar- 

- gillaceous nodular beds; some of the harder bands full of Gaprina 

occidentalis Conrad______________________ 75

Farther east some of these beds are repeated, dipping eastward. 

It is evident that these beds are in part the equivalent of those described by Tan0 as occurring in Flat Mesa, 4 miles north of Sierra 

Blanca, and that they should be included in the Fredericksburg 

division.

About 10 miles south of Quitman Canyon and less than 2 miles 

south of the northern boundary of the Eagle Mountain quadrangle 

the east face of the mountain shows a similar section, and at its base 

there are small exposures of Washita beds with Schlc&nbachia vespertina and a few other forms, dipping toward the mountain and 

thus giving additional evidence of overturning and faulting.

The Rio Grande section. Still farther south, near the Rio Grande, 

the upper part of the section is much more complete and more simple, 

furnishing the key to the sections already discussed, which are parallel with it across the same line of uplift. The eastern end of the 

section is about 1 mile north of the Rio Grande in the first hills west 

of the board valley of Quitman Arroyo. Here the beds are sharply 

folded a'ncl a prominent ridge shows an anticline consisting of argillaceous limestone belonging to the Washita division.

The western limb of the anticline dips 70° to 80° west, and the exposure is as follows:

Section in Mils just 'west of Quitman Arroyo, about 1 mile north of the Rio 

Grande (Section V of map).

Feet.

1. Argillaceous limestone, weathering in nodular form, with bands of

harder limestone________._____________________ 200

2. More massive limestone, much seamed and fissured______________ 30

8. Dark, fissile shale, with occasional bands of impure brown limestone, 

underlying a valley about .1 mile wide. Dips at first steep to the 

west, becoming variable and much less toward the middle of the 

valley and again steep to the west on the west side of the valley. 

Inoceramus laMatus and a few other Upper Cretaceous fossils were 

found west of the middle of the valley; thickness apparently several thousand feet.
 STANTON.] THE CKETACEOUS. 31

Fee't.

4. Massive limestone, probably same as No. 2___.________ 30

5. Argillaceous limestone with some bands of clay and sandstone; fossils : Nodosaria texana, Enullasl'er texamis, Neithea texana. Exof/yra arietina, E. dralcei var., Plicatula incongrua, and other Washita forms________________________________ 300

0. Heavy-bedded limestone (40 feet) forming a cliff, followed by argillaceous nodular limestone "(30 feet), which yielded Enallaster texanus, Gryphwa corruf/ata, Lima wacoensis, ~Neithea texana, and 

SchlcenbacliAa vespertina-________________________ 70

7. Similar limestones with dip not less than 45° westward______ 300

8. More argillaceous light-gray limestone, interstratified with dark clay 

shales; one of the limestone bands yielded Epiaster whitei, Terebratula (Kinyena) wacoensis, Grypha:a washitaensis (?), Plicaluki 

incongrua, and SchlvenbacMa vespertina, and another baud farther 

west yielded Epiaster wMtei, Schlcen'bacMa, acutocarlnata, 'S. serratescens, and Hamites fremonti_ ____________..___ 300

9. Dark clays with brownish calcareous bauds; Exogyra texana abundant ___________________-__--__-__________ 50

10. Covered ____.____._______________________'.________ 100

11. Limestone, very heavy-bedded above, with increasing bands of argillaceous limestone below; Requienia and a small conical Foramiuifera abundant; Exogyra texana also occurs_________ 300

12. Shales, limestones, and bands of brown sandstone, not well exposed_ 250

13. Argillaceous limestone, with some harder bands containing " Caprina "

and Requenia____/_________________-__________ 75

14. Generally more massive limestone with some bands of brown sandstone. Also contains " Caprina," Ostrea, etc_____________ 350

15. Quartzitic sandstone with thinner bands of clay shale and impure

limestone, dipping steeply westward_______________..___ 400

16. Haj'd, blue limestone, full of OrMtolina texana __________.____ 60

17. Sandstone and impure limestone with some clay__ ____ ___ ___ 40

18. Sandstones and clays___________-, _____--_-_-__-___- 250

19. Thin-bedded passing into massive limestone,, full of Orbitolina texana;

at least_________._._..___.._______.______________________ 300

The steep western surface of No. 19 forms the eastern wall of the 

canyon of the Rio Grande at this point.

So far there has been no apparent serious break in the section, but 

the beds now become complexly faulted and folded. A short distance north No. 19 is cut off by a fault, and on the west, across the 

river, the same bed seems to be repeated in several postures.

It is evident that the eastern portion of the section crosses a syncline, so that in passing from No. 1 to No. 5 the same beds are all 

crossed twice. In the rest of the section, while there may be some 

repetition of beds due to small faults, there are no anticlines nor 

synclines, and the fossils show that in general the beds are successively older toward the west. No. 3 is Upper Cretaceous, of the 

age of the Fort Benton; Nos. 4 to 8 are Washita; Nos. 9 to 14, and 

probably 15, are Fredericksburg; and Nos. 16 to 19 belong to the 

Trinity. As the dips are all steep to the west it follows that all the
32 . MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

beds from No. 4 to No. 19, inclusive, are overturned. It will be seen 

also that the succession of rocks and fossils is similar to that found 

on the east slope of the mountains near Quitman Canyon, and that 

there is no place for the great sandstone series of the " Mountain 

bed " Avithin the Washita division. It must be older than the Orbitolina limestone.

Eagle Mountains. These mountains, which lie 10 miles east of the 

southern end of Quitman Mountain, are composed mostly of igneous 

rocks, but sediments are exposed on. their'-flanks. My examinations 

were along only the western base, where there are some exposures of 

Fredericksburg limestone and shales and apparently some Trinity 

limestones. Mr. Taff reports Upper Cretaceous and the Orbitolina 

limestone on the other side of the mountains, and fossils in the collection of Prof. W. F. Cummins, at Dallas, indicate the presence of 

upper Washita beds " 1 mile north of gap in Eagle Mountains."

Sierra Blanca. This group of conical peaks, about 6 miles northwest of the railroad station of the same name, is also composed of 

igneous rocks with Cretaceous sediments around the base. On the 

southwest side of the main peak there are fossiliferons exposures of 

Fredericksburg age noteworthy for containing Exogyra texana and 

Nodosaria texana in the same bed. The same association is found in 

the Finlay Mountains also. Beds of about the same age with E. texana and Actceonella dolium occur in Flat Mesa, about 4 miles east.

In the saddle between the main peak and the north peak of Sierra 

Blanca there are considerable exposures of very fossiliferous Washita 

beds with many characteristic species.

Finlay Mountains. These hills begin about 4 miles north of the 

north end of Malone Mountain and 6 miles northwest of the main peak 

of Sierra Blanca and extend several miles to the north and northwest. 

They were rather hastily examined in the hope of finding an extension of the Malone'beds, but the only fossiliferous beds seen belong to 

the Fredericksburg division of the Cretaceous, including the horizon 

of Actceonella doliwn. There are many intrusive masses of igneous 

rocks and at one locality a considerable development of a coarse calcareous conglomerate whose relations were not definitely determined, 

though it seemed to belong to the Cretaceous.

Other localities. Other exposures in the neighborhood of Sierra 

Blanca station were examined, especially Bluff Mesa and Pevils Ridge, 

without very definite paleontological results. The top of Bluff Mesa, 

?. miles southwest of Sierra Blanca, is composed of Orbitolina limestone, and it is probable that the underlying beds belong within the 

Trinity division.

The Orbitolina limestone, the Quitman bed, and a considerable 

thickness of Fredericksburg beds are well exposed in the neighbor-
STANTON.] THE CEETACEOUS. 33

hood of the abandoned "A L Ranch " on the Rio Grande west of 

Quitman Mountains, in the small triangular area bounded by the 

river and the Eagle Mountain and Fort Hancock quadrangles. The 

Fredericksburg beds are especially well exposed about 2 miles down 

the river from the ranch, in the small canyon locally known as the 

' Cajoncito." The next prominent ridge, 3 or 4 miles to the east, 

shows Washita shales and limestones, with intervening dark shales 

that may belong to the Upper Cretaceous.

These details of the stratigraphy and distribution of the Cretaceous 

in this region are given for the purpose of emphasizing the peculiarities and the isolation of the Malone beds.

Bull. 266 05 M 3
DESCRIPTIONS OF THE SPECIES.

ANTHOZOA.

Several coralla of the massive shape and a segment of a digitiform 

branch, which in my preliminary manuscript on the Malone fauna I 

had described as two species of Astroccenia, were eventually submitted to Mr. T. Wayland Vaughan, Avho is engaged in a special study 

of the Neozoic corals, for more detailed study than I could give them. 

Of these, Mr. Vaughan has very kindly furnished the following 

description:

Genus ASTROCCENIA M. Edwards and Haime.

ASTKOCCENIA MALONIANA Sp. 11. 

PI. II, flgS. 1-3.

" Professor Cragiri has submitted to me for study and description 

9 specimens of an Astroccenia collected by him 1-^- miles east of 

Malone, Tex. The original substance of the skeleton has been transformed in the process of fossilization into a bluish limestone; the 

skeletal elements are now represented by crystalline calcite and the 

interspaces are filled by the same mineral. The result of these 

chemical changes is to make a study of the thin sections of the 

specimens very unsatisfactory. No minute structural features could 

be deciphered, and very often even the grosser ones of the individual 

corallites are obliterated or can be discovered only with difficulty.

"Apparently only one species is represented in the collection, but 

there is a central or type form around which the other specimens can 

be grouped. The type form will be described first.

" The corallum is a gibbous mass, with a fiat base having a rather 

large surface; the upper surface is rather uniformly rounded or 

thrown into numerous mammillae. The intergradation between these 

two types of upper surface can be seen in the specimens before me. 

When the mammillate character has reached its maximum development the external appearance of the corallum is identical Avith that 

of the common recent West Indian Forties astreoides Lamarck. The 

dimensions of two large specimens, both of which possess the mammillate upper surface, are :

ram. mm. 

Greatest breadth ___ __ _____ ____ ________ -___ _______ 113 9G

Least breadth _____ __________ ___ ___ . _ _ ____ _ __ _ 95 82

Height ______ _ .___ - ___ __ __ 52 50 

34
CRAG IN.] DESCRIPTIONS OF SPECIES. 35

" The above represents the type form of the corrallum. There is 

one specimen, with a mammillate surface, which shows no place for 

attachment, and other specimens show a tendency to form low 

columns.

" The corallites are polygonal, usually hexagonal, are crowded 

together, and are joined by their directly fused walls. The wall 

between adjoining corallites is usually thin, but in some instances it 

may be rather thick, in extreme cases almost 1 mm. When the wall is 

thin, its upper edge is acute; when it is thick, it is flattened between 

adjoining calices. The depth of the calicular cavity is so variable 

that it possesses no value in the specific diagnosis; it is sometimes 

deep and sometimes very shalloAv in the same colony. The diameter of the calices vary in the same colony from 1.5 to 2.5 mm. The 

minimum diameter for a calice is 1 mm. and the maximum is about 3

mm., or a very little less. The number of septa is 16 or 20. There are

either 8 or 10 principal septa, A\7 ith smaller ones between. At their 

margins the septa are usually rather thin, but deeper down in the 

corallite are secondarily thickened. The septa are thicker peripherally at the wall and are also thickened around the columella. The 

septa of adjoining corallites meet end to end or alternate with each 

other. In transverse sections of corallites dissepiments are very 

rarely present. ' No further information can be given concerning 

the endotheca. The columella is small, low, weak, and styliform. 

Below the bottom of the calice it is strengthened by having the 

thickened inner terminations of the principal septa fuse around it. 

Gemmation takes place in the angle between .adjoining corallites.

" There is another specimen not included in the above. It is an - 

Astroccenia, apparently growing in digitate branches. There is not 

enough material to warrant naming and describing it."

ECHINOIDEA.

HOLECTYPOIDA. 

Genus HOLECTYPUS Desor.

HOLECTYPUS? Sp.

An echinoid fragment indicating a test shaped as in this genus, but 

with the details too poorly preserved to allow a satisfactory description or an- absolute generic identification, was obtained by Doctor 

Stanton from an anticline on the east slope of Malone Mountain, 

about 1 mile north of the southern end.
36 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

SPATANGOIDA.

Genus PYGURUS Agassiz.

PYGURTJS sp.

Among the specimens submitted by Doctor Stanton is a fragment of 

the test of a sea-urchin of the genus Pygurus. It includes the main 

part of the aboral half of an ambulacrum. The genus is clearly 

determined by the form of the ambulacrum and the form and arrangement of the pores, as well as by the character of the tubercles and by 

the discoidal form of the test, the latter form being indicated by the 

flatness of the part preserved. The ambulacrum has the biconcave 

outline that characterizes the upper part of that of Py gurus. The 

pores of the outer row are very long and slit-like, widened slightly 

toward the outer end, and subhorizontal to more or less oblique; those 

of the jnner row more ringent, compressed dot-like or hyphen-like, 

and oblique, their width being considerably less and their length considerably more than that of any of the circumtubercular courts on the 

neighboring part of the ambulacrum. The ambulacra! plates are 

exceedingly narrow; the imperforate part of each, in the widest part 

of the ambulacrum, being about ten times as long' (transverse) as 

wide (parallel to the course of the ambulacrum) and ornamented 

with 1 to 3 small perforated tubercles, each of which is set in a round, 

depressed court. The distribution of these tubercles is irregular, but 

they are so few and so feebly developed on the inner ends of the 

plates as to give the ambulacrum the aspect of having a median plain 

zone, to which the seams between the plates give a transversely striated appearance.

Measurements. Maximum width of ambulacrum 16, of which the 

two pore belts each occupy 3.5 and the imperforate. tract 9 mm.; 

length and width of imperforate part of an ambulacral plate in 

broadest part of ambulacrum, respectively, 4.5 and 0.43 mm.; length 

of outer slit-like pores in broadest part of ambulacrum 2 mm., which 

is about one-fourth of the width of a semiambulacrum.

Occurrence. West side of Malone Mountain, about 2 miles southAvest of Malone station, in No. 25 of Doctor Stanton's Malone Mountain section; with Gryphcea mexicana, Pleuromya inconstans, Pinna 

quadrifronS) etc.
CHAGIN.] DESCRIPTIONS OF SPECIES. ' 37

VERMES.

ANNELIDA.

TUBICOLA.

Genus SERPULA Linmeus.

SERPULA GORDIALIS Schlotheim.

PI. II, figs. 5-6.

A round-tubed, nearly smooth, irregularly constricted, at first 

spirally coiled, then contorted Serpula, probably the same as that 

noted by Doctor Felix a from the upper Jurassic rocks of the Cerro 

de Titania in the State of Oaxaca, Mexico, and referred by him to 

Schlotheim's 8. gordialis, is the commonest tubicolan of the Malone 

fauna, having been found at the anticline in the eastern base of 

Malone Mountain (in both Doctor Stanton's collections and mine), 

and at the locality 1^ miles east of Malone station. The largest tubes 

observed measure about 2.7 mm. in diameter, 1 to 2 mm. being a more 

common size.

SERPULA sp.

<, 

PI. II, fig. 4.

Not rare at the locality last mentioned is a large Serpula, apparently differing from S. gordialis chiefly in size, but perhaps also having a less constantly or less intricately contorted habit. As there 

found, it attains a diameter of at least 8 mm.

SERPULA sp.

A single specimen of a third and well-marked species of Serpula 

was obtained from the same locality, but was lost in the laboratory 

when it had received only preliminary study. The following are its 

characters so far as they were noted :

Tube considerably smaller than an average one of Serpula gordialis, straight, round, and at least in part terete, its exterior ornamented with close, uniform or nearly uniform, prominent, filiform, 

encircling costellse, so that its appearance recalls one of the smaller 

of the wound wires in the lower register of a piano; an ornamentation which contrasts strikingly with the plain to feebly and irregularly 

constricted exterior of the two other known Serpulse of this district.

Beitriige Geol. u. Pal. Mex., pt. 3, p. 175. Palaeontographica, vol. 37. 1891.
38 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

MOLLUSCOIDEA.. 

BRYOZOA.

DIASTOPORID^E. 

Genus BERENICEA Lamouroux.

BERENICE A MALONIANA sp. n. 

Pi. II, fig. 7.

Colonies incrusting, sometimes conflueritly associated, unsymmetrically flabelliform, apparently without a tattered or incised border; 

cells numerous, several hundred in a colony, tubular, arising as if separately in quincunx-radial order from the smooth or finely porous membrane-like stock which separates them by intervals for the most part 

about equal to themselves, the lower part of each cell being embedded 

and subhorizontal, the outer part rising obliquely and becoming gradually free or nearly so, being wholly free at the very extremity only; 

free surface of cells plain or at most only finely striate; oral extremity 

contracted, the aperture small and round.

Measurements. Breadth of colony, 12 mm.; of cell, 0.2 mm.; of 

oral aperture, about 0.1 mm.; greatest exposed length of cells between 

twice and thrice their breadth.

Occurrence. -The type specimen covers between a fourth and a 

third of one of the larger whorls of a Nerinea goodellii and parts of 

the two "whorls preceding and following, and is. met by another similarly radiating colony of which only a border portion is preserved, 

the line of contact of the two colonies being heaved up into a ridge, 

It is from the locality 1-^ miles east of Malone station.

In the partially embedded cells and in the resulting apparent separation of the tubes from each other this species resembles Berenicea 

microstoma Mich., as illustrated in fig. 6b of PL I of Reuss's " Bryozoen, Anthozoen und Spongiarien des Braunen Jura von Balin bei 

Krakau," a but it lacks the undulatory transverse furrows of that 

species and has the tubes less strongly inflated and proportioned much 

as in the B. tenera Reuss. The last-named species is, however, very 

different in having the tubular cells visibly in contact instead of separated by a conspicuous basal stratum that conceals their deeper and 

contiguous parts.

« Denkschr. k. Akad. Wiss., Math.-Nat. Classe, vol. 27. Wien, 1867.
CRAGIN.] DESCRIPTIONS OF SPECIES. 39

MOLLUSCA. 

PELECYPODA.

OSTREID^E. 

Genus OSTREA Linnaeus.

OSTREA Sp.

Three imperfect valves of an ovate, thin-shelled ostreid, about 1^ 

inches in greatest dimension, lie partly embedded on a piece of blue 

limestone obtained from the Theta, i-£ miles east of Malone station, 

and may represent Ostrea as distinguished from Exogyra and Gryphsea. They are, however, incomplete in the region of the beaks 

and their precise relationship therefore remains somewhat uncertain. 

The inflation is moderate and due almost wholly to the strongly 

incurved border, the remainder of the valve being rather flat.

Since in general aspect they recall species of Ostrea in the stricter, 

and certainly at least represent it in the broader generic sense, while 

they do not seem referable to any of the hitherto described Ostreidse 

of the .Malone Jurassic, they are here provisionally listed as above.

(jRYPiyEA MEXICANA Felix. 

PI. Ill, figs. l-G.

Gryphcra mexicana Felix, 1891, Beitr. Geol. u. Pal. Mex., pt. 3, p. 178, pi. 

27, figs. 30, 30a.

Shell rather small, more or less inequilateral and cuneate; adductor scar elongate, lightly impressed; margins of the valves not crenulated internally, the right valve very much smaller than the left, 

rounded-triangular, usually flat or exteriorly in part concave, thickened in the dorsal part; left valve triangular to crescentic-triangular, 

deeply excavated, strongly arched on the dorsal region, the posterior 

part more prominently so than the anterior, its beak high-arched, 

strongly incurved and rather bluntly (seldom freely) hooked, usually swinging a little backward, its posterior side strongly flattened 

or concave, the passage thence to the outer side more or less angulated or sometimes elevated as an obtuse fold, a similar but smaller 

flattening or concavity being often present on the shorter, anterior 

hide, exterior side usually convex sometimes flattish or concave 

antero-posteriorly and either without bordering sulci or provided 

with an anterior or posterior sulcus or with both; the growth-lines 

sometimes acute and imbricated, especially on the anterior and posterior slopes, but on the exterior slope often more commonly thickened 

at irregular intervals into obtuse wave-like elevations and often here 

also swung upwards into a broad sinus. In specimens of smaller and
40 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

medium sizes at least, the left valve is often ornamented with fine, 

radiating raised lines, including, more conspicuous ones, which are 

rather remote, and numerous closely arranged, almost microscopically 

fine ones, there being usually 2 to 7 of the latter in each of the 

intervals between the former. This ornamentation is usually well 

expressed in very young examples, and these present considerable 

resemblance in form as well as sculpture to certain species of Plicatula, but in the arched valve, held beak upward and seen in exterior 

A~iew, the longer side will appear on the right in the young'Gryphsea 

and on the left in Plicatula, since the arched valve is the left in 

Gryphsea and the right in Plicatula and the posterior side of the 

shell is longer than the anterior in both genera. A very similar ornamentation is seen on the arched valve of Meek and Hayden's Black 

Hills Jurassic form, (rryphcea calceola var. nebrascensis. In exceptional specimens, G. mexicana approaches the latter species in form 

also, tending to a uniform antero-posterior convexity, even the posterior flattening being slight. Much more common than this, however, 

is the occurrence of specimens with anterior and posterior sides both 

strongly flattened or concave.

Measurements. Specimens of an ordinary size give height, 43 mm. ; 

length, 32 mm.; breadth, 17 mm.; but considerably larger specimens 

are often found.

Occurrence. Common at several levels below the Iota conglomerates, a mile and a half east of Malone station, where scores were 

collected, and less so a few feet above similar conglomerates in 

an anticline in the east flank of Malone Mountain; in the latter 

locality associated with Pleuromya inconstans, Modiola maloniana, 

Astarte malonensis, Exogyra subplicifera? and Serpula gordialis. 

The species was also collected by Doctor Stanton, both at these and at 

the following localities: About a mile east of Finlay station; west 

side of Malone Mountain, west and also south of west from Malone 

station (at the last-named locality in Nos. 13 and 25 of his Malone 

Mountain section); from foothills west of Malone Mountain, about 2 

miles north of its southern end; at the west base of the mountain, 

near its southern end; and from the east slope of the mountain, near 

its southern end, 200 or 300 (?) feet above the gypsum.

One of the most striking features of G. mexicana is the posterior 

flattening of the left valve, a feature of which is much more strongly 

expressed in this shell than in any other species of Grypha^a with 

which I am acquainted.

The prevailing size of the shell is not the same at all localities, 

some specimens of the largest average size coming from the \vest side 

of Malone Mountain; but at no locality in the Malone district does the 

shell average so small as the Oaxaca examples figured by Doctor 

Felix.
CRAGIN.] DESCRIPTIONS OF SPECIES. 41

Genus EXOGYRA Say.

ExOGYRA SUBPLICIFERA Felix. 

PI. IV, flgS. 1-4.

Exogyra. sulplidfera Felix, 1891, Beitr. Geol. u. Pal. Mex., Pt. Ill, p. 177, 

pi. 27, figs. 6, 7.

From locality H miles east of Malone station, and associated with 

most'of the commoner fossils described in this paper, were collected 19 

specimens, besides 8 obtained by Doctor Stanton. Two somewhat 

doubtful casts were also found, with Gryplma mevcicana, Astarte 

malonensis, etc., just above the beds of conglomerate, at the eastern 

base of Malone Mountain, in the anticline about 1 mile north of the 

southern end of the mountain.

The shells occur both free, or nearly so, and attached .by nearly the 

whole of the left valve. The largest example from the Malone Hills 

has a length of 35 mm., but some of the smaller ones agree nearly in 

size with the Mexican specimens t described and figured by Doctor 

Felix from the Cerro de Titania. The right valve has the beak 

strongly recurved laterally, and sometimes has the anterior dorsal 

border drawn across the umbonal cavity so as to form more or less of 

a cul de sac, and in the more nearly free examples is rather thin, 

deeply excavated, and ornamented with numerous imbrications which 

present distally an obtuse angle on the summit of convexity, and in 

some of the young examples may have 1 to 4 faintly expressed radial 

folds on the basal part. In yo.ung specimens the right valve is more 

or less triangular, broad across the distal part, and a little produced at 

the base; in the adult it usually becomes auriform.

The following is a translation of the original description by Doctor 

Felix, relating_to the right valve, which is exceedingly characteristic 

and on which alone the species was established:

It is of auriform sometimes rather elongate, sometimes more broadened 

contour, like the Cretaceous Evoyyru, auricularis Brongn. sp., which has been 

regarded by Coquand as a variety of his E. plicifera. On its inner surface it 

bears a variable number, mostly 5 to 8, cf transverse folds, which are in strong 

relief, but do not extend across the entire shell breadth, by which sculpture it is 

especially distinguished from related forms. It may be taken for granted that 

if adult examples show this sculpture on their inner side, free or only umbonally 

adnate' individuals will show it on their outer surface in at least as distinct a 

manner as the Cretaceous E. plicifcra Coqu. possesses it.

The length of the specimen in the middle amounts to 15 miu.

EXOGYRA POTOSINA C. and A. 

PI. Ill, fig. 7; PI. IV, fig. 7.

Exoyyra potosina Castillo and Aguilera, 1895, Faun. Foss. Sierra el. Catorce, 

p. 3, PI. II, fig. 9.

Doctor Stanton's collection contains six specimens that are referred 

to this species. All are larger than the Mexican type specimen fig-
42 MALONE JURASSIC FOKMATIOIST OF TEXAS. [BULL. 266.

ured by Castillo and Aguilera. Three, of which one closely resembles 

the example of "E. subnoclosa Minister," figured in Goldfiiss's Petrafacta germanice (PL LXXXVI, fig. 8), are from the foothills west 

of Malone Mountain, about 2 miles north of the southern end of the 

mountain, there associated with Gryphcea mexicana, Pinna quadrifrons, Pleuromya inconstans, etc. The three others, representing a 

variety of more broadly triangular outline, are from the west base of 

the mountain, only a short distance north of its southern end. The 

latter station, according to Doctor Stanton's notes, may or may not 

represent the same horizon as the former and " is certainly several 

hundred feet above a horizon of Gryphcea mexicana and Nerinea."

The specimen, above compared to E. subnodosa, has a convexity of 

about 40 mm. and a lateral profile whose greatest extent, from beak to 

anterior part of base and extent transverse to the same,- are respectively 8G and 55 mm.' Corresponding dimensions in one of the larger 

and broader specimens from the second station above specified are 

respectively and approximately 39, 93, and 73 mm.

The following is a translation of Castillo and Aguilera's description of Exogyra potosina:

Shell elongated, oblique, laterally curved, ot! seiiiilunar contour. Right" 

valve inflated, its major convexity situated near the umbo, incurved like the 

shells of Gryphrea; provided with an obtuse crest that traverses the shell in 

its. entire length forming a curve concentric with the anterior margin ; beak 

little free and gently recurved laterally. Left valve operculiform. depressed, 

and adapted to the concavity which the right valve forms; beak rudimentary. 

Surface provided with growth-laminaj more marked in the left valve, which is 

entirely lamellar; on the right valve are perceived two pliciform nodules, 

obtuse and imperfect, upon the indistinct crest of the shell. Length, 57 ram.

Castillo and Aguilera further describe the shell as intermediate 

between Exogyra and Gryphsea, noting that it approaches the latter 

genus both in the general form of the two valves and by preponderance of the vertical over the lateral curvature of the umbonal region. 

In the Texas specimens, however, at least sometimes, the lateral curvature seems to preponderate.

It is possible that the narrower and broader forms represent two 

species; but this does not seem probable, and they are here provisionally regarded as mere phases of one.

Exogyra potosina in the Sierra cle Catorce, has been recorded only 

from relatively high beds, which Castillo and Aguilera have considered as Cretaceous. It apparently occurs only high in the Malone 

district also; but some of its associates in the latter district are 

apparently identical with the lower occurring Pleuromya inconstant 

(of the Theta and Alamitos) ; Gryphcea mexicana (of the Theta and 

Jurassic of Oaxaca) ; Pecten insutus, Pinna quadrifrons, Lucina

" Left, of authors generally, who regard the operculiform valve as the right in the 

inequivalve. forms of this genus.
CUAGIN.] DESCRIPTIONS OF SPECIES. 43

metrica, and Astarte malonensis (?} (of the Theta) forms which are 

themselves the common associates of Trigonia calderoni (Theta and 

Alamitos) ; Astarte microphyes (Theta and Jurassic of Oaxaca), etc.

SPONDYLID^E.

Genus PLICATULA Lamarck.

PLICATULA SPORTELLA sp. n.

PI, HI, figs. 8, 9.

Shell small, well inflated by the convexitj7 of the broadly rounded, 

somewhat inequilateral and twisted, broadly attached right valve; 

left valve nearly flat, its margin rather thick; both valves strongly 

plicated to the correspondingly crenulated margins, the ribs about 10 

on each valve; ribs of the left valve with broadly rounded summits, 

the furrows between them narrow, those of the right valve with narrower, more widely separated summits, and separated by roundbottomed furrows; surface of ribs and furrows on both valves crossed 

with imbricated growth lines.

Measurements. Height, 8 mm.; length, 10 mm.; breadth, 5 mm.

Occurrence.. Malone Hills, 1^ miles east of Malone station. The 

type and only specimen is attached to a shell of Nerinea goodellii.

LIMID^E. 

Genus LIMA Bruguiere.

LlMA INTERLINE AT A Sp. 11. 

PI. IV, figs. 5, 6.

Shell small, obliquely oval, the anterior border straight or very 

slightly convex, the oval being more elongate than that of Lima 

cremdicosta Roemer, and the lateral profile more nearly approaching 

that of L. wacoensis Roemer; the convexity of the valves, however, 

agreeing more nearly with crenulicosta, and the beaks somewhat 

more elevated than in either of those species; either valve ornamented 

with about 22 radiating ribs; the ribs tcctiform, having two faces 

that meet at an angle considerably greater than a right angle; the 

ribs separated by intervals about as wide as themselves, the middle 

of each interval marked by a raised line, or, in the case of a few of 

the posterior intervals, by two to three such lines. It belongs to the 

subgenus Radula.

'Measurements. Length and breadth of the oval, respectively, 16 

and 12 mm.

Occurrence. Represented b.y a right valve and several fragments 

from locality 1-| miles east of Malone station, and, of Doctor Stanton's collecting at same locality, by a left valve with moderately
44 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

prominent, anterior ear. Doctor Stanton also obtained a fragment 

from about a mile south-southeast of Finlay station.

LIMA (CTENOSTREON) RIOGRANDENSIS sp. ii. 

Pi. v, fig. 4.

Shell large and thick, equivalve, somewhat inequilateral, or obliquely round-oval (the base swung somewhat forward), ventricose, 

anteriorly gaping, radially large-ribbed; ribs broad and low-convex, 

about 11 or 12 in number on each valve, separated by flat-concave 

intervals about as broad as themselves; the surface marked with 

sinuous-concentric groAvth lines and coarse, laminated imbrications 

which present convexities upward and downward on the ribs and 

intervals respective!}^ the laminated imbrications in places thickened 

so as to nearly fill the shallow intervals. The ears of the type are 

broken off. The presence of a byssal sinus is indicated by the direction of the growth lines on the basal remnant of the anterior ear.

.Measurements. Height about 125 mm.; length about the same; 

breadth, 80.5 mm. The thickness of the shell varies from about 7 

mm. on the basal slope to about 13 mm. in the dorsal region.

Occurrence. Only the single type specimen is known. This was 

found on the upper part of the Theta outcrop, 1-i miles east of Malone 

station, associated with specimens of Trigonia vyschetzkii, Astarte 

malonensis, etc.

The species seems to considerably exceed in size Ct. proboscidea 

Sby., of the Oxford. The only Ctenostreon that has hitherto been 

known from North American rocks is an undescribed species reported 

by Hyatt from the lower Jurassic of Taylorsville, Cal.

PECTHSTIDJE.

Genus PECTEN Klein.

PECTEN (CAMPTONECTES) INSDTUS sp. n.

Pi. rv, figs. 11, 12.

Shell pyramidal-subcircular, somewhat inequilateral, with greater 

anterior than posterior extent, inequivalve; left valve having a fair 

degree of convexity; right valve flattish-convex; beaks rather 

pointed, not rounded in well-preserved specimens, the right one but 

slightly inflated; anterior straight or slightly concave and posterior 

usually slightly convex (sometimes in part incipiently concave) ; 

dorsal margins of body of either valve making a right angle, or often 

considerably less than a right angle, with each other; anterior ear 

large, its hinge, or crest line, about twice as long as that of the posterior ear, and its anterior margin reaching about three-fourths as far
CRAG IN.] DESCRIPTIONS OF SPECIES. 45

in advance of the beaks as does the anterior margin of the valve 

itself, its byssal sinus angular or subangular; surface of both valves 

ornamented with numerous fine, closely set, rounded to flattened, 

radial, linear costellse, separated by narrower, serially punctate, 

strioeform grooves, and crossed by concentric growth lines, of which 

some at irregular intervals are more or less strongly imbricated; 

punctations commonly approaching the form of a circumflex accent, 

sometimes appearing dot-like, very closely ranked.

Measurements. Height, 39 mm.; length, 34 mm.; breadth, 10 mm. 

(right valve 3, left 7).

Occurrence. About 50 specimens were collected, in the Malone 

Hills, H miles east of Malone station, the species ranging nearly 

throughout the fossiliferous Theta there exposed; in foothills about 

1 and 2 miles a little south of east from'Finlay station; at a point

about 2 miles west of Malone station; about three-quarters of a

mile farther south (all of the four last-named localities representing 

the same or nearly the same horizon, No. 13 of Doctor Stanton's 

Malone Mountain section) ; and at the anticline in the east slope of 

Malone Mountain, nearly a mile north of its southern end.

Before obtaining a copy of Felix and Lenk's Beitrage zur Geologic 

mid Palaeontologie der Republik Mexico I had characterized and 

named in manuscript the above-described common Malone fossil, giving it the specific name insutus, in allusion to'the peculiar stitched 

appearajice of the seams between the ribs. Its ornamentation closely 

resembles that of the Lima comatulicosta, described in that work, 

from the uppeu Jurassic of Mexico. It differs, however, in several 

respects from that form, as described and figured by Doctor Felix." 

It is provided with ample ears, of which the anterior is several times 

the larger; it is inequivalve; its beaks, instead of being rounded, as 

described and figured by Doctor Felix in his Lima comatulicosta, 

are, when perfectly preserved, rather pointed; and, finally, its outline 

is less obliquely or anteriorly elongated, sometimes even approaching 

in the body of the valves an equilateral or circular outline Avith a 

pyramidal summit, though usually rather oblique and somewhat 

elevated.

The break possibly indicated at the position for an ear in fig. 5 

(loc. cit.) of Lima comatulicosta,i]\Q apparent identity of the costal 

and intercostal ornamentation of the Malone Pecten with that shown 

in figs. 1, la, 3, 3a of the Cerro de Titania shell, and the fact that, 

unless the Pecten insutus be it, the Lima comatulicosta is not known 

from the Malone district, while its appearance there might reasonably 

be expected (since at least two 6 of the seven lamellibranchs described 

by Doctor Felix from the Upper Jurassic of the Cerro de Titania

" Beitrage, etc., in Palaeontoguapliica, vol. 37, p. 178, PI. XXVII, figs. 1, la, 3, 3a, 5. 

* Exogyra subplicifera and Gryphaxi mexicana.
46 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

have been found to be common to both localities), are circumstances which at one time led me to regard the alleged Lima as probably identical with the common Pecten of Malone. But that the 

differences of form are considerable, as above shown; that Doctor 

Felix gives two figures oi.Lima comatulicosta which agree essentially 

with each other in all respects in which either differs from Pecten 

insutus; that he compares his fossil with a European species of Lima « 

from the coral rag, and that the peculiar intercostal punctation is 

knowjn to occur both in. Lima and in Pecten, are considerations in 

VJGAV of which the assumption that the Mexican fossil has been 

wrongly referred to Lima is not warranted. 

The radially ornamented outer layer of this shell rapidly weathers 

off, leaving a shiny black surface, so that sometimes the shell appears 

smooth or bears only subdired concentric markings.

The specimen figured represents the more circular phase of the 

vpecies and shows the beaks less pointed than they appear in most. 

examples.

. Genus GEEVILLIA Def ranee. 

GERVILLIA COKRUGATA sp. n. 

PI. IV, figs. 8-10.

Shell inequivalve, very inequilateral, obliquely elongated and 

curved; hinge provided with several cartilage-pits, the one "anterior 

to the beaks being relatively small; the left valve crescentic as viewed 

from above, sigmoid as viewed from without, its beak curved forward, 

inward, and downward,, its postero-basal part curved backward, 

upward, and inward; the right valve (including beak) flattened,

its posterior umbonal slope monoclinally angulatecl, the steep and 

narrow post-umbonal slope, separating the anterior, anteroposteriorly flat-convex, proximo-distally flat or slightly concave main 

part of the valve from the relatively depressed posterior wing; anterior wing small or of moderate size, that of the left \7 alve a little 

contorted, posterior wing rather large, its angle drawn out posteriorly to a point, owing to the strong emargination of its posterior 

border; umbo of left valve radially corrugated, the adjoining part 

of the left posterior wing similarly ornamented on a smaller scale, 

remainder of left and the right valve marked with ordinary growth- 

 lines.

Measurements. Height,'' 25 mm. ; length, 38 mm. ; breath, 12 

mm. Portions of several large specimens indicate at least twice these 

dimensions.

0 L. comatula, Buvignier.

6 Height and length taken as usual, perpendicular and parallel to the hinge-line.
CHAGIN.] DESCRIPTIONS OF SPECIES. 47

Occurrence. As yet known only from the Malone Hills, 1-| miles 

cast of Malone station, and only moderately common in the lower 

part of the Theta beds of that locality, occuring with several of the 

smaller species -of Gastropoda. Gryphcva mexicana, which ranges 

much higher, is also one of its commoner associated fossils. Twentythree imperfect specimens and fragments Avere collected.

GERVILLIA CINDERELLA sp. n.

 PI. V, fig. 1. .

Shell subequivalve, moderately inflated, somewhat flattened on the 

flank, falciform, the basal region being much produced posteriorly, 

its terminal part tapering; basal margin long, straight, convex; 

posterior border concave; flank-region limited supero-posteriorly 

and in part anteriorly by an abruptly rounded shoulder, the surface being drawn steeply in to the base of the wing; posterior shoulder 

continuous from the beak to the upper part of the posteriorly produced basal region, its axis gently curved with concavity looking 

upward and backward; anterior wing inflated above, concave and 

more distinct from the body of the valve below; posterior wing 

large, falcate (?) (largely broken off in the type), surface bearing 

delicate concentric growth lines.

Measurements. Height, 32 (plus several) mm.; length, about 

(probably a little more than) 57 mm.; breadth, 19 mm.

Occurrence. One specimen, wanting the cardinal region, was 

found by Doctor Stanton in the horizon of the broader phase of 

Exoyyra potosina at the west base of Malone Mountain, a short 

distance north of the southern end.

GERVILLIA ? RIOGRANDENSIS sp. n. 

PL V, figs. 2, 3.

Another species of lamellibranch, here provisionally referred to 

Gervillia, was found at the west base of Malone Mountain, associated 

with G. Cinderella. It is represented by a cast, of which considerable 

of the upper posterior region has been removed by weathering, and 

which bears fragments of the shell of the left vah^e. The form is less < 

elongate and more compressed than that of G. Cinderella; the anterior 

border is concave, the ventral border slightly so, the adjoining lower 

part of the flanks being slightly hollow, owing to the strong compression of the ventral region. As compared with G. Cinderella, the 

antero-ventral border is more prominent and regularly rounded. The 

shoulder separating the flank from the posterior wing appears, from 

the cast of part of it, to have been much more gently molded, and this 

Aving seems to have had much greater cWelopment in its lower part; 

surface, as impressed on the mold of a shell fragment, marked Avith
48 MALONE JUKASSIC FORMATION OF TEXAS. [BULL. 260.

fine growth lines, of which some, occurring at short subregular intervals on the distal parts, are more strongly imbricated than others.

Measurements. Height, about 40 mm.; length, 38 mm. (plus 5?) ; 

breadth, 17 mm.

Occurrence.- Known only by the above-described specimen, associated Avith Gervillia Cinderella, Exogyra potosina, Pleuromya inconttans, etc.

MYTILID^E.

Genus MYTILUS (Linn.) Brug.

MYTILUS NUNTIUS sp. n.

PL VI, figs. 4, 5.

Shell small, equivalve (or slightly tortuous-inequivalve?), rather 

compressed, the right or left profile arched cuneate-oblong, considerably less attenuated anteriorly than that of the somewhat similarly 

proportioned recent species, Mytilus afer Gmelin, the angle made by 

the anterior margins of the cast being about three-fourths of a right 

angle; beaks terminal, subacute, gradually and moderately deflected 

upward, directed much more forward than upward; valves apparently smooth or marked only with concentric growth lines.

Measurements. Length (oblique) of lateral profile, 21 mm,; 

breadth of same, 10 mm.; breadth of shell, about 6 mm.

Occurrence. A single well-preserved cast, bearing thin remnants 

of the shell, was found among the lower occurring fossils (Gervillia 

corrugata, Pleurotomaria circumtrunca, etc.) of the Theta 1-| miles 

east of Malone station. A form without trace of shell, observed on 

the matrix of a Trigonia vyschetzkii from the same locality, probably 

represents a valve oil: the same Mytilus and indicates for it a somewhat larger size.

Though the longitudinal axis of this shell is arcuate, the arching 

is so gentle that the outline approaches that of the straighter-profiled 

Mytilus afer, as figured by Tryon,tt more than one of such strongly 

curved forms as sublmvis, eduliformis, and decussatus.

Genus MODIOLA Lamarck.

MODIOLA MALONIANA Sp. n. 

PI. VI, figs. 1, 2.

Shell of moderate size in its genus, oblong-trapezoid, gently arched, 

broadest near the middle, the anterior and posterior regions rather 

narrow and elevated, the height being greatest at or in advance of the 

posterior fourth; beaks small and only moderately elevated above the 

hinge line, placed close together, nearly or quite in contact anteriorly, 

their dorsal summits forming rather narrow longitudinal ridges from

n Struct, and Syst. Conchol.
CKAGIN.] DESCRIPTIONS OF SPECIES. 49

either of which there proceeds to the posterior part of the basal margin a low, broadly rounded, umbonal swell, below which in the intermediate region the flanks are concave ; surface nearly plain, marked 

only with ordinary growth lines, some of which are imbricated.

Measurements. Height across umbonal region, 11 mm.; same at 

highest section of the shell, 12.5 mm. ; length, 37.5 mm. ; breadth, il 

mm. Another example attains a length of 43 mm.

Occurrence. The type is from locality li miles east of Malone station, which has yielded two other specimens. I have found a single 

example also, associated with Pleuromya inconstant, Astarte malonensis, Exogyra subplicifera ?, Gryphcea mexicana, and Serpula 

gordialis, at the eastern base of Malone Mountain, in the transverse 

anticline 1 mile from its southern end, just above conglomerates. 

Two additional specimens were obtained by Doctor Stanton, one from 

the anticline just mentioned and one from about 1 mile east of Finlay 

station.

MODIOLA GENICULATA Sp. n. 

PI. VI, fig. 3.

Shell small among its congeners, much shorter and higher relative 

to its breadth than M. maloniana^ geniculate-trapezoid, the vertically 

expanded posterior half of the shell being rather suddenly deflected 

downward and backward so that its axis makes an angle of about 45° 

with the horizontal cardinal border of the vertically smaller anterior 

half ; breadth less than the height, greatest about the middle ; beaks 

moderately raised, little inflated; flanks concave in the mid region 

below the umbonal convexity; surface apparently marked only with 

the ordinary growth lines.

Measurements. Height, 16 mm.; height of section across middle, 

12.5 mm.; length, 25.5 mm.; breadth, estimated from convexity of one 

valve, 10 mm.

Occurrence. A single left valve was collected by Doctor Stanton 

about 1 mile east of Finlay station.-

Genus PINNA Linnaeus.

PINNA QUADRIFRONS sp. n.

Pi. VII, figs. 1-8.

Shell of medium size in its genus, elongate-cuneate ; anterior region 

inflated, in cross section bicuspidately round-oval to quadrate-oval; 

posterior region rather compressed, in cross section nearly rhombic; 

valves meeting by their ventral margins at an acute and more or less 

compressed or cariniform angle and by their dorsal margins at a 

somewhat similar angle; from their anterior, more convex part, beBull. 266 05 M 4
50 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

coming at first feebly and then, on the middle and posterior region, 

strongly and abruptly obtuse-angulated along a radial line a little 

above the middle, so that either valve presents two slopes a dorsal, 

which is flat or in part feebly concave, and a somewhat wider ventral, 

which retains some convexity even on the posterior part; dorsal slope 

of either valve ornamented Avith 10 to 15 compressed and gently 

elevated radial costellse, which are separated by intervals wider than 

themselves and obliquely scored by numerous growth lines that give 

the costellse a more or less granulated or crenulated appearance; ventral slope marked only with strong, pliciform, for the most part very 

oblique growth lines. The summit of the supra-median angle is the 

locus of a linear hingelike plait, or gore, by whose ready erosion the 

valves are often cleft, especially along the middle and posterior 

region, each into two A^alvelike -segments, so that broken specimens 

which include only that region appear not only tetragonal and quadrilateral, but also quadrivalvate.

Measurements. H eight (across larger end), 56 mm.; breadth 

(across same), 30 mm.; length; 240 mm.; all approximate.

Occurrence. One and a half miles east of Ma lone station. This 

is one of the most abundant fossils of the Theta subdivision in that 

locality and ranges nearly throughout the known fossiliferous thickness of it. It usually occurs in sections varying in size from less 

than 1 inch to 4 or 5 inches long, of which about 80 were here obobtained. Some have been subjected to pressure in such a manner as 

to make them nearly square in cross section. Doctor Stanton also 

obtained several on the west side of Malone Mountain, as follows: 

One in No. 25 of his Malone Mountain section, 2 miles south of west 

Malone'station; 2 from a foothill about 2 miles northwest of the 

southern end of the mountain, and 6 from the west base of the 

mountain, a short distance north of its southern end. Part of those 

(casts), from the last-named locality are more than usually compressed, rapidly expanded, and somewhat curved, and at first sight 

suggest a distinct species or variety; but others are of intermediate 

form and some bear shell remnants with seemingly characteristic 

quadrifrons ornamentation, so that, while individual variation may 

have played a part, the exceptional form should probably be attributed chiefly, if not wholly, to the distortive influence of the orogenic 

forces that have acted upon the matrix containing them.

ARCID^EL 

Genus ARC A Linnaeus.

ARCA TAFFII sp. n. 

PI. VI, figs. 7. 8.

Shell small, ventricose, broader than high, of moderate length; 

beaks strongly arched, inrolled, and brought into contact; posterior
CEAGIN.] DESCRIPTIONS OP SPECIES. 51

slope angulatecl and strongly flattened (radially costate?); anterior 

slope a little excavated on the upper part, separated from the outer 

slope by a rounded shoulder, ornamented with-a few strongly elevated 

radial costa? separated b}^ comparatively wide intervals, in each of 

Avhich is a feebler linear costella; outer slope flattened, radially costate, becoming closely cancellated on the middle and strongly so on 

the ventral part; ventral margin straight, not crenulated. There are 

20 of the costse on the outer slope,.small, with their rounded summits 

subgranulated by the cancellation, arid separated by intervals of about 

their own width. On the summit of the umbo the axis of flattening 

is inclined forward.

Measurements. Height, 10.5 mm.; length, 19 mm.; breadth, 12 mm.

Occurrence. One and a half miles east of Malone station; represented by only one example.

The ornamentation .of the posterior slope is concealed in the type 

specimen. A radiately costate ornamentation upon it is inferred 

from the fact that the species seems to agree subgenerically Avith 

Gray's Calloarca as described and figured in Tryon's Structural and 

Systematic Conchology. A slight inequality of the valves in the 

umbonal region is doubtless a distortion due to stratigraphical disturbance. The specimen does not disclose the characters of either 

the hinge or the ligamental area. 

ARCA ? DUMBLI sp. n. 

Pi. VI, fig. 6.

Shell small, only moderately inflated, rather elongate-trapezoidal, 

the anterior side short and subvertically truncate, the posterior long 

and obliquely truncate; the base gently convex; the moderately elevated beaks situated at the rear limit of the anterior third; anterior 

slope small, concave, wing-like, with supero-anterior corner nearly 

a. right angle, separated from the outer slope by a posterior umbonal 

angulation, which becomes obsolete distally; posterior slope concave, 

separated from the outer by a strong, proximally subacute, distally 

obtuse shoulder-like angulation, the two apposed concave slopes 

forming together a sort of wing with obtuse corner; the anterior 

slope ornamented with a few narrow, distally obtuse radial folds, 

the outer slope with ordinary and strong concentric groAvth-lines, 

radial lines, if originally present here, having been feeble and obliterated by weathering in the types, the posterior slope and the summit 

of its limiting angle having numerous radiating raised lines and striae.

Measurements. Height, 16.5 mm.; length, 30 mm.; breadth, about 

12mm.

Occurrence. One and a half miles east of Malone station; represented by 5 specimens.
52 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

The hinge characters of this shell are unknown. While the general form permits little doubt that it is one of the Arcidse, there is 

less certainty of its generic position, and it is placed only provisionally under Area.

The species is named for Mr. E. T. Dumble, late State geologist of 

Texas.

Genus CUCULL^EA Lamarck.

CUCULL./EA? TEXTICOSTATA sp. n. 

Pi. VI, figs. 9, 10.

Shell ventricose, short, subtriangular, somewhat pointed inferoposteriorly, rounded anteriorly, the posterior slope flattened and 

making an angle with the outer slope; beaks well inflated and elevated; entire surface marked in a crowded manner with radiating 

linear costella'-, and in large part with- erect concentric lines of imbrication, of which the latter are the finer and more crowded (seen to 

advantage only when magnified), and the former the more conspicuous and more persistent under weathering. A considerable part of 

the surface when magnified appears woven, like cloth or miniature 

basket work, except for the alternating arrangement seen in the 

latter. This woven ornamentation resembles that seen in Area taffii, 

the radial costellse being, however, much finer and more numerous 

than in that anteriorly and posteriorly otherwise ornate and altogether differently shaped arcid.

Measurements. Height, about 29 or 30 mm. (?); length. 34 mm.; 

breadth, 24 mm.

Occurrence. One specimen and a fragment of a second; 1£ miles 

east of Malone station.

In the absence of any knowledge of the hinge of this shell it is not 

possible to be sure whether it is a Cuculla?a or an Area. The ornamentation primarily radial and secondarily cancellated is of a 

type more common in'the latter genus; but the species is put provisionally in Cucullsea, under the subgenus Trigonarca, on account of 

its triangular, form.

CUCULLSEA TRANSPECOSENSLS Cragin.

CucullaM transpecosensis Cragin, 1893; Fourth Ann. Kept. Geol. Survey 

Texas, pt. 2, p. 175.

The genus Cucullsea is not represented by abundance of individuals 

in any of its species in the rocks of the Malone formation in Texas, 

and so rare is the massive and ventricose G. transpecosensis that, 

despite careful collecting for many days at the locality which yielded 

Messrs, von Streeruwitz and Wyschetzki the type, the latter still 

remains the only specimen known of this species.
CRAGIN,] DESCRIPTIONS OF SPECIES. 53

As it has not been practicable to restudy the type, the original 

account of the species is here reproduced, which is as follows:

Shell large and thick, ventricose (subrhornboidal?) ; beaks large, remote from 

the anterior extremity, their summits very obtuse as viewed from the side or 

from above, their apices less compressed and less free than in C. tenninalis or 

C. gratioti;* anterior dorsal border prominent and compressed, subaliform, the 

surface included between it and the [anterior?1 ] line of the beaks being ornamented with raised radial lines, posterior dorsal angle (apparently) shorter and 

lower than the anterior, posterior umbonal slope prominently angulated, the 

angulation succeeded on the inner side by a pronounced sulcus, which is in turn 

limited on its inner side by another angulation less prominent than the first; 

hinge-area broad, divaricate-grooved; anterior'lateral denticles four (and one 

rudimentary), long, strong, and horizontal, their abruptly deflected inner termination being relatively very short. Mesial and posterior denticles unknown.

Occurrence. Collected by Mr. von Streeruwitz about 1 mile northeast c of 

Malone, El Paso County, with Venus malonensis d and other forms, as mentioned 

under that species. Comanche series.6 .

In size this Shell apparently exceeds the other known species of Cuculltea from 

the Comanche series of Texas.

CUCULL^EA CATORCENSIS C. and A.

Cuculltsa (Trigonarca) catorcensis Castillo and Aguilera, 1895, Bol. Com. 

Geol. Mex., No. 1, p. 5, PI. IV, figs. 1, 4, and 5.

Two small Cucullaea casts, of medium ventricosity, obtained below 

the Iota conglomerates, 1^ miles east of Malone station, and two from 

above similar conglomerates in the eastern base of Malone Mountain, 

in the anticline about 1 mile north of its southern end, are referred to 

the young of this species.

" /The following is a translation of Castillo and Aguilera's description of Cucullam catorcensis, as given (loc. cit.) in their "Fauna Fosil 

cle la Sierra de Catorce: "

Shell bulky, very convex, of quite variable contour, oval in the young examples, subquadraugular in those which are more developed, and subtrapezoidal 

in the adults. Beaks broad, very prominent and little removed from one another, 

situated in the anterior third and nearly terminal in the adult examples, pro? 

vided with a carina on the anal side. Buccal region very much more short than 

the anal, rounded on the extremity, a little excavated near the cardinal border

0 C. terminaUs Con. and G. cjratioti Hill, of tbe Comanche Cretaceous.

6 Reads " posterior," by error, in the original.

c The same locality is herein generally called " li miles east of Malone station," and ia 

perhaps a little short of the latter distance, so far as occurrence of the larger number of 

the fossils is concerned. I have understood that all of the fossils obtained from this 

spot In 1890 were actually collected by Mr. Wyschetzki; and if so, the name of Mr. von 

Streeruwitz was probably put on the. label in view of his having been in charge of the 

trans-Pecos division 'of the Texas survey.

d ' Astarte malonensis of the present writing.

« For explanation of the manner in which the few fossils known from this locality in 

1893 were at that time placed in the Comanche series, see Introduction. Instead of 

" Comanche series," read Malone formation.
54 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

with which it forms an acute angle. Anal region obliquely truncate on its 

extremity, excavated or concave in the vicinity of the bonks, limited by a wellmarked carina which traverses the shell from the beak clown to the posterior 

extremity at its junction with the inferior border of the shell; the carina is 

quite acute near the beak and becomes more obtuse in proportion as it recedes 

from it; the umboual region, thus circumscribed by the umbonal crest, forms 

a sort of corselet, quite marked and excavated. Middle region of the shell 

convex and in the form of a triangle limited by the anal crest and the other 

less developed which separates it from the buocal region; the major convexity 

of the shell is just, adjoining the anal crest and near the beaks. Ligaiuental 

area not very much excavated and of regular dimensions. Cardinal border 

straight, in some specimens nearly as long as the shell, but in others much 

shorter; anterior border obliquely rounded; inferior border nearly straight and 

parallel to the cardinal border, joining by means of a curve with the posterior 

border, which is oblique, slightly curved, and in the joung forms nearly parallel to the anterior border. Surface of the shell provided with concentric lines 

of growth which have suffered interruptions and constitute more or less prominent corrugations. '

Length, 60.62 mm.; breadth with relation to the length, 0.58.

Locality: Arroyo de Alamitos, on the Alamitos rancho, in the Sierra de 

Catorce.

By breadth (" ancho ") in the above is meant the dorso-ventral 

dimension called height by some writers. The lateral breadth, called 

thickness (" espesor ") in the " Fauna Fosil," is not stated. ~

The massiveness of this shell, its ventricose form, its broad beaks, 

and the demarcation of the middle from the posterior umbonal slope 

by a cariniform angulation, are features which might seem to indecate that Cucullma catorcensis should be referred to the Texan C. 

transpecosensis; but the very prominent and subterminal beaks, and 

(so far as the description indicates) the absence of a second, or inner, 

angulation on the posterior corselet and of raised radial lines on tfie 

anterior umbonal slope in C. catorcensis, appears to sufficiently distinguish the latter as a valid species.

CUCULLTEA CASTILLOI Sp. 11. 

PI. VI, figs. 11, 12.

Shell of moderate size in the genus, short-trapezoidal; ventricosity 

of medium degree, greatest'considerably above the middle; ante-, 

rior side short, rounded; posterior side straight, obliquely truncate; 

base gently convex; the infero-posterior part of the shell somewhat 

pointed, owing to a prominent, rapidly rounded shoulder that runs 

from either beak to the junction of the ventral with the posterior 

border, separating the outer convex slope from the posterior slope, 

which latter is strongly and concavely depressed, being strongly 

inflected near the shoulder and turning outward again about midway 

of its extension toward the posterior border, to form a prominent
CRAGIN.] DESCRIPTIONS OF SPECIES. 55

and sharp keel by union with the corresponding border region of the 

opposite valve; anterior umbonal slope only feebly angulated or 

shouldered; beaks narrow, high-arched,_approximated, placed slightly 

in advance of the middle third; flank region marked with concentric 

growth lines; posterior slope finely and closely striate.

Measurements. Height, 39 mm.; length, about 48 mm.; breadth, 

about 34 mm.

Occurrence. Two examples were collected by Doctor Stanton in 

foothills at the northAvest end of Malone Mountain, about 2 miles 

east-southeast of Finlay station. Neither shoAvs the ornamentation 

of the anterior slope.

The species is named for the late Prof. Antonio del Castillo, 

founder-director of the Geological Institute of Mexico.

Genus LEDA Schumacher.

LEDA ? NAVICULA sp. n.

Pi. vi, fig. 13.

Shell fairly well inflated, elongate-ovate, anteriorly not shortened, 

posteriorly produced and gradually narrowed or subrostrate; the 

anterior subhorizontal and posterior gently declined parts of the dorsal side each forming a small concavity adjoining the beak, anterior 

side rounded, base long and straight-convex for the greater part, its 

posterior part ascending obliquely; beak small and little salient, 

placed a little back of the anterior third.

Measurements. Height, 11.5 mm.; length, 25 mm.; breadth, about 

10 mm.

Occurrence. A cast of a left valve was found embedded in the 

rock fragment bearing one of the specimens of Unicardium semirotundum collected by Doctor Stanton at the anticline on the east slope 

of Malone Mountain about 1 mile north of its southern end.

A cast of a small, posteriorly produced lamellibranch, which was 

supposed in' the field to be one of the Nuculidse and which may have 

been a Leda, was observed in Theta a mile and a hall east of Malone 

station. It,was accidentally destroyed in attempting to remove it 

from the matrix. A rough sketch of it, preserved in my notes, indicates a shell similar in form to that above described, but smaller. It 

may be referred to Leda? navicula, but is represented as having the 

margins crennlated, while this character, if it belonged to the latter 

species, can not be distinguished in the type as preserved.
56 MALONE JUKASSIC FORMATION OF TEXAS. [BULL. 266.

TRIG-ONIIDJE.

Genus TKIGONIA Brug.

TKIGONIA VYSCHETZKII Cragin.

PI. VIII, figs 1, 2; PI. IX, figs. 1-3.

Trigonia vyschetskii Cragin, 1893, Fourth Ann. Kept. Geol. Survey Tex., pt. 2.

p. 215; and, 1897, Jour. Geol., vol. 5, No. 8, pp. 816, 817. 

Cf. Trigonia soloynreni Felix, 1891, Beitr. Geol. u. Pal. Mex., pt. 3, p. 179,

PI. XXVII, figs. 2, 2a.

Shell large, of moderate convexity, transversely subquadrate; postero-dorsal side straight; anterior and posterior sides truncate; base 

gentty curved; beaks only moderately arched; area flattened, occupying about one-fourth of the valve, bordered above and below by a 

tuberculated ridge or angulation, and traversed by a median groove 

which is accompanied by a third such ridge less developed than those 

of the border, a large distal part of it obliquely crossed in most 

instances by numerous strong, more or less irregular and interrupted 

folds, or ornamented on the proximal part with rows of tubercles 

by whose increasing confluence on the intermediate and distal parts 

the folds are produced, the tubercular endings of these folds usually 

descending across the entire outer slope of the bounding ridge, and 

in some cases even passing a little beyond it; escutcheon depressed, 

crossed with a series of transverse, somewhat oblique, straight, or 

in part slightly curved, tubercular costellae; preareal surface ornamented with about 15 gently curved nodose costre, which are subvertical near the infraareal ridge and make with the latter at first 

an acute and then approximately a right angle, descending for the 

most part obliquely, though .steeply, to the base; the costee attenuated, 

and simpler near the area, becoming resolved into irregularly more 

and more robust nodes as they recede from it, the posterior and intermediate costae thus enlarging throughout, while a few of the shorter 

anterior ones, turning forward at their lowr er ends across the flattened front of the shell, are here again reduced to nearly simple 

ridges which dwindle and disappear before reaching the valve margin ; nodes mostly close ranked, commonly 12 to 16 on the larger ribs 

of adult shells, rounded, often more or less compressed so as to trend 

with the growth lines, a rib often having a single very large node 

near the basal margin of the valve especially thus elongated; intervals between the costae coarsely concentrically striate. The separation 

of the siphonal currents is indicated, as in the Clavellatse and Scabrae, 

by a ridge on the interior of the shell. The ornamentation shows considerable mutability, and a variety occurs in which the entire area 

is covered with small compressed tubercles. In one specimen the 

costellae of the escutcheon are simple.
CUAGIN.] DESCRIPTIONS OP SPECIES. 57

Measurements. Approximately, height, 76 mm.; length, 87 mm.; 

breadth, 50 mm. Two ver}7 young examples have these dimensions, 

respectively, 16, 17, 10, and 25, 27, 15 mm.

Occurrence. '-So far as the collections show, this Trigonia does not 

occur in the Malone district, except in the Malone Hills and in the 

Theta subdivision of the Trio section. In these, however, 1-J miles 

east of Malone station, it becomes numerically one of the commonest 

fossils of the Malone formation. In the rich collecting tract there, 

on the basal slopes of the Truncate mound and the southeast base of 

hill C of the Trio, and especially on the western basal slope of the 

former, it was found by scores, in one or two places being agglomerated in beds, mingled more or less with other fossils. Between 75 

find 100 specimens of it are represented from this tract. But if the 

shells of other Malone fossils, as here preserved, prove fragile under 

the rigorous temperature changes of a plateau climate, that of Trigonia vyschetzkii is so especially, and of the large number collected 

many are in half-released fragments, and comparatively few make 

even tolerably fair cabinet specimens. I also found this fossil about 

half a mile west-northwest of this locality on the south side of the flat 

saddle that separates the Trio from the low gypsum-parted ridge 

which continues the hill range in that direction.

The series of quadrate pits mentioned by Lycett ° and cited by 

Steinmann 6 as occurring posteriorly on the interior of the valve near 

the ventral margin in Quadratse, is lacking in T. vysclietzkn. The 

form differs from that of the Quadrates and agrees with that of the 

Clavellatse in being considerably longer than high, yet agrees with 

Quadratse and differs from Clavellata3 in being quadrilateral instead 

of subtriangular. In having the escutcheon ornamented and in 

some usually slight tendency which the areal folds manifest to 

infringe on the general surface below the limiting angle, on the posterior region, the shell agrees with the Quadrates.

The T. vyschetzkii is thus seen to be closely related to the South 

American T. transitoria Steinm., upon which and the related T.. herzogi Hausmann, of South Africa, Steinmann, in 1882, proposed to add 

Pseudo-Quadratce ° to the previously known sections of Trigonia. Its 

profile is usually less elongate and the ornamentation, especially that 

of the area, and escutcheon, less coarse than in T. transitoria, the 

folds of the area descending the lower slope of the limiting angle, but 

descending only a little (sometimes not at all) below it on the posterior region.

Normal casts of Trigonia vyschetzkii are differently proportioned 

from that which from Tlaxiaco, Mexico Doctor Felix figures as

" Mon. Brit. Foss. Trigon., p. 100.

» Neues .Tahrb. fiir Mineral., 1882, vol. 1, p. 221.

e Loc. cit., pp. 219-228, Pis. VII-IX.
58 MALONE JURASSIC FORMATION OF TEXAS. [BOLL. 266.

the type of his T. sologurenif a shorter, more elevated, and much 

more ventricose form being indicated for the latter species. But the 

cast of T. vyschetzkii, in one or two of our specimens, somewhat 

approaches that of T. soloyureni in form, while several species of 

fossils are common to Malone and Tlaxiaco; so that it is desirable to 

compare actual shells of these two species with one another as well as 

with the shell of T. transitoria.

TRTGONIA GOODELLII Cragin. r 

PI. X, figs. 1, 2.

Trigonia gooilellil Cragin. 3897, Jour. Geol., vol. 5, p. 816.

Shell of about medium size in its genus, produced ovate, ventricose; 

valves thick; beaks situated near the rear limit of the anterior fourth, 

low, strongly inflated, in contact, their posterior slope strongly angulated to form the limiting angle of the area; area flattened, nearly 

plain, having numerous fine oblique growth lines, with a few small 

folds crossing it near and concentric to the beaks, these folds being 

continuous of and making an angle with those in front of the area, 

some low tubercles along the marginal angles, and a faint mesia! 

sulcus; escutcheon bearing only inconspicuous folds which radiate 

from the ligament, those of the proximal part being nearly transverse 

to the length of the escutcheon and continuous with those of the corresponding part of the area; general ornamentation consisting of a 

series of ribs, which on the posterior part of the preiireal surface 

are large, obtuse, and plain or subtuberciilated, separated by roundbottomed valleys of about their own width, and descend almost vertically .(the earlier ones more obliquely forward) from the inferior 

border of the area, increasing in size each to an elbow-like angle, at 

which they turn abruptly forward, becoming reduced in size to 

costellte in front of these elbows and partially resolved each into a 

series of small tubercles, these costellae being accompanied each by one 

or two similar ones in the intervals between them, the costellae diminishing gradually in size and swinging into the course of ordinary 

growth lines on the anterior region, and there becoming continuous 

and like strong reversed imbrications, each presenting its acute and 

more elevated border dorsad. The series of costal elbows radiates at 

first downward and then obliquely downward and backward from 

the beaks.

Measurements. Height, 42 mm.; length, about 58 to 60 (plus?) 

mm.; breadth, 35 mm.

" Versteinerungen aus deni oberen Jura cles Cerro de Titania bei Tlaxiaco im Staat 

Oaxnoa, 1891, Beitr. Geol. u.' Pal. Mex., pt. 8, Talaeontographica, vol. 37, p. 179, PI. 

XXVII, figs. 2, 2a.
DESCRIPTIONS OF SPECIES. 59

Occurrence. One and a half miles east of Malone station. Besides the original example \vhich the Messrs. Goodell discovered, and 

from which the illustration and measurements have been taken, 17 

other imperfect specimens and fragments were obtained at this 

locality, some of them indicating dimensions perhaps a fourth larger 

than those of the type.

It will be seen from the description that the ornamentation of 

T. goodellii is variable. This, however, is true of most Trigonias, 

and not least so of those of the section, Undulata?, to which this species 

belongs.

None of the Old World Undulatse known to me corresponds very 

closely with T. goodellii. Several of those from the Great Oolite, 

which is so rich in Undulatse, bear more or less resemblance to it; but 

the strict analogue, if found, may be expected to occur in the 

Tithonian.

The species was named after the late Mr. Robert Wood Goodell, 

whose kind services in assisting me to determine the age of the Malone 

formation I have particularly acknowledged in my article on the 

" Discovery of marine Jurassic rocks in southwestern Texas," the 

paper in Avhich the species was first briefly characterized and named.

A Trigonia cast, showing nothing of the ornamentation, but indicating the general form of T. goodellii, having still larger dimensions 

than any of the above, and belonging not improbably to this species, 

was obtained by Doctor Stanton from conglomerate on the west face 

and near the top of Malone Mountain. It gives the following measurements: Height, 62 mm.; length, 72 mm:; breadth, 46 mm.

TRIGONIA CALDERONI (C. and A.). 

Pi. IX, figs. 4-6.

Goniomya, calderoni Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., No. 

1, p. 9, PI. V, figs. 17, 18.

Shell elongate-trapezoid, very inequilateral, moderately inflated, 

the region of greatest convexity extending from the umbones downward and backward; anterior region relatively short and of considerable height relative to the posterior, the anterior contour rounded: 

posterior region strongly produced backward and inclined a little 

upward, gradually and strongly tapered toward its extremity, which 

is obliquely truncate and looks backward and upward, its flanks more 

or less flattened; base gently convex below the beaks, ascending thence 

anteriorly in an easy convex curve and posteriorly slowly.in a long 

and nearly straight line; beaks but moderately elevated, their apices 

curved inward and somewhat backward and downward; escutcheon 

rather large and long, plain; area of moderate width, flattened, traversed lengthAvise by a mesial groove, and transversely linear-plicate,
60 MALONE JURASSIC FORMATION OF TEXAS. [BOLL. 266.

the plicules separated by striae ; preareal surface ornamented with two 

sets of ribs, of which the anterior ribs are acute, upwardly-imbricate, 

remote, subhorizontal, with gentle sigmoid flexure, presenting a slight 

upward convexity below the beaks and a downward one farther, forward, and alternately reach the more anterior ribs of the other set; 

posterior ribs thicker, more obtuse, and more narrowly intervalecl 

than the anterior, nearly straight, and directed steeply downward and 

backward from the limiting angle of the area, the proximal of these 

being the more nearly vertical and the distal and independent ones 

more oblique, the intermediate ones being the longest. Slight irregularities sometimes appear in the course of the anterior ribs, each of 

which, in one example, bears a small dorsally directed angle at the 

summit of its infraunibonal convexity.

Measurements. One of the Texan examples, which has a length 

of 58 mm., indicates for the shell in part restored, a height of 32 mm. 

and a breadth of 23 mm., approximately.

Occurrence. The Malone formation yields this fossil rather sparingly. Eleven specimens and characteristic fragments are represented. Eight of these are from the Malone Hills, 1£ miles east of 

Malone station ; the others were collected about a mile east of Finlaj^ 

station.

In the character of the preareal ornamentation, the species presents considerable resemblance to Trigonia sulcataria Lamarck, as 

figured by Lycett on Pis. XXVI and XXVIII .of his British Fossil 

Trigoniae, a species which has been referred to the Undulatse, but is 

shown by Lycett to belong to the Scabrse. The plain escutcheon, 

however, at once separates T. calderoni from the Scabme, and the 

same and all of the other external characters refer it to the UnduTRIGONIA PROSCABRA sp. ri. 

PI. X, figs. 3-6.

Shell small, crescentic- ovate or subsemi circular, the upper border 

strongly excavated, anteriorly inflated, gradually becoming more 

compressed toward the posterior extremity; beaks somewhat produced and recurved; escutcheon large, broader than the area, ornamented with rather remote, coarse, but not very strongly elevated, 

oblique costellse; area flattened, narrow, transversely linear-plicate, 

traversed by a mesial depressed line, and bounded both above and 

below by a row of tubercles, those of the lower row surmounting a 

distinct limiting ridge and larger than those of the preareal costse 

opposite whose terminations they are placed; the areal plications, 

though fine and numerous, are mostly separated by intervals Avider 

than themselves; preareal surface denticulate-costate, the denticles
CRAGIN.] DESCRIPTIONS OF SPECIES. 61

cuneiform, each consisting of a superior, compressed, tuberculiform 

head and an attenuated cariniform process which dwindles to a point 

below, crossing the longer and gentler posterior costal slope, but not 

crossing the fundus of the intercostal valley quite to the base of the 

comparatively abrupt anterior costal face. The costa; are moderately 

interspaced, becoming rather widely intervaled when the shell attains 

the adult size. A small flattened tract formed by the conjoined 

antero-dorsal margins, is minutely wrinkled transversely, to the 

margins, as the earlier ribs, before reaching the margin, become suddenly reduced and changed to minute linear folds, paralleled in 

their intervals by similar folds, of which there are two in each 

interval.

Measurements. Height, about 30 mm.; length, 36 mm.; breadth, 

21 mm. One specimen, represented by a considerable part of a right 

valve, indicates, with a breadth of about the same or a millimeter less, 

a height and length 2 or 3 mm. greater. Young examples are relatively shorter, or more elevated, one such example having height 20 

mm.; length, 20 mm.; breadth, 14-mm.

Occurrence. One and a half miles east of Malone station. About 

35 specimens are represented, many of them only by fragments. A 

crushed specimen from this locality has the costal and areal ornamentation exceptionally well preserved and shows- an almost spinous 

prominence of the denticles. A cast, representing the anterior twothirds of a right valve on which the costse are indicated as plain 

undulations, obtained by Doctor Stanton about 1 mile east of Finlay 

station, is supposed to belong to this species, b,ut may represent T. 

prcestriata.

Trigonia proscabra.presents points of resemblance especially to two 

of the sections of its genus, and does not agree entirely with either. 

It may be regarded as one of the Clavellatue which, both as to form 

and preareal ornamentation, has assumed the habit of a common 

phase of the Scabrae. In having an ornamented escutcheon it differs 

from the typical Clavellatse, though not from the Pseudoquadratse 

which are intermediate between Clavellatai and Quadrates. In having the area bounded on each side by a row of tubercles and below by 

a pronounced limiting ridge it resembles the Clavellatae.

'TRIGONIA PRJESTRIATA sp. n.

PI. X, fig. 7.

Shell small, crescentic-ovate, only moderately inflated; area strongly 

and closely striated in a direction oblique to its length, bounded belo\v 

by a rather strongly compressed and prominent limiting ridge or 

angulation; preareal ribs about 12 or 14 in number, coarse, remote, 

and strongly elevated, descending divergently and for the most part
62 MALONE JURASSIC FORMATION OF TEXAS. [BOLL. 266.

more or less vertically, and increasing rather rapidly in size from the 

Jimiting angulation to the ventral and anterior borders, about twice 

as wide as the plain, flattish-concave intervals between them, their 

summits obtuse and strongly and a little obliquely cross-striated in 

such a manner that the striation is visible if the ribs are viewed tangentially from in front, but invisible if so viewed from behind.

Measurements. Height, 21 mm.; length, 30 mm.; breadth, 10 mm.; 

approximately.

Occurrence. A single mold, representing the greater part of a 

right valve in excellent detail, is the type and only known specimen. 

It was obtained by Doctor Stanton on the east slope of Malone Mountain, near its southern end, 200 or 300 feet above the gypsum bed that 

there forms the mountain's base. It lacks the escutcheon, the upper 

part of the area, and the umbonal apex, but the exterior characters of 

nearly all of the rest of the shell may be readily observed either in the 

mold or on the gutta-percha squeeze taken from it. The species is 

referred to the section Scabrse.

TRICONIA MUNITA sp. n.

PI. X, figs. 8-11.

Shell ovate-pyramidal, of medium or rather large size among its 

congeners, moderately ventricose, rather elevated; valves thick; area 

strongly flattened, separated from the preareal surface by a very 

large and prominent, obtuse, somewhat imbricated radial costa, preceded by a furrow, the areal surface being ornamented with two 

rather strong, not widely separated, cariniform radial costse, which 

are separated from each other by an interval that is rather narrow as 

compared with that between either costa and the corresponding areal 

border, and several similar but smaller costellse or rays, there being at 

least two such rays in the .anterior interval; preareal surface ornamented with (25 to 30?) strongly and rather abruptly elevated concentric ribs, which resemble low Avails, terminate almost abruptly at 

the preareal furrow, and are in large part only about half as wide as 

the flattish-concave intervals between them.

Measurements. These can not be exactly given, owing to the imperfection of the material, but about the following dimensions are apparently indicated in one instance: Height, TO mm.; length, 75 mm.; 

breadth, 42 mm. In another the height is about 80 mm.

Occurrence. Represented by three very imperfect specimens and 

a number of characteristically ornamented fragments. One of the 

specimens were obtained by Doctor Stanton near the south end of 

Malone Mountain, west face, near top, and another west of the mountain, about 2 miles west of Malone station. The remainder of the 

material is from the locality 1| miles east of Malone station. All of
CEAGIN.] DESCRIPTIONS OF SPECIES. 63

the known material represents the adult condition, or at least rather 

large sizes of the shell, unless the two specimens described under the 

head of Trigonia rudicostata should be interpreted as the young of 

T. munita. This species with the two that follow belongs to the section Costatse.

TRIGONIA RUDICOSTATA sp. n.

PI. XI, figs. 1, 2.

Shell small, ovate-pyramidal, nearly straight (slightly convex) on 

the postero-dorsal, broadly convex on the ventral, and less broadly so 

on the anterior side, inflation intermediate in degree; beaks situated 

at rear limit of the anterior fourth, prominent and acute at the compressed and transversely placed summit, excavated on the posterior 

side, turned inward and.somewhat backward; area nearly flat, shallowconcave on its proximal part, wide, making Avith the preiireal surface an angle greater than a right angle, and separated from it by a 

compressed, prominent radial costa, Avhich is larger than any other 

costa of the shell, the area posterior to this costa being ornamented 

Avith 4 or 5 similar but narroAver and smaller rays, between each two 

of Avhich are 3 to 5 still smaller, strongly elevated, linear rays or 

costellse, the intercostellar' spaces being at least as Avide as, or for the 

most part Avider than, the rays themselves, preiireal surface ornamented with about 25 strongly elevated, round-topped ribs which 

parallel the basal margin and are mostly slightly wider than the 

intervals between them. There are 7 of the horizontal or concentric 

ribs in the loAver half in one specimen and 10 on the lower 10 mm. in 

another.

Measurements. Height, 23 mm.; length, 27 mm.; breadth, 16.5 

mm.

Occurrence. The tAvo specimens in the collections Avere obtained 1^ 

miles east of Malone station.

Although the material thus far available for study indicates between T. rudicostata and T. munita differences of both radial and 

concentric ornamentation too marked to be ignored, it is quite possible that new material from localities known or yet to be discovered 

may^shoAv that these differences are due to conditions of age or individual variation; for it is noteworthy that, except the types of T. 

rudicostata, no Costata) eA^en approaching Avhat we should predicate 

for the young of T. munita, have been found.

TRIGONIA CONFERTICOSTATA sp. n. 

Pl. XI, fig. 3.

Shell small, subtriangular, of the section Costatae, apparently 

more elevated than T. rudicostata/ posterior area costellate Avith
64 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

linear rays, of which there are 5 to 7 smaller in the shallow-concave 

interval between each two of the larger; a large radial rib anteriorly limiting the ^^rea; preareal surface ornamented with about 40 

strongly elevated concentric ribs which are much finer than those of T. 

Tudicostata and between one and a half times and twice as numerous, 

and are separated by intervals prevailingly narrower than themselves. In a specimen smaller than the largest, but which nearly 

corresponds in size with the type of T. rudicostata, there are 15 ribs 

on the lower 10 mm. of height of the vah^e, as compared with 10 on 

the same part of the height in the said example of T. rudicostata. 

As against 7 ribs included in the lower half of T. rudicostata, there 

are in one specimen of conferticostata not less than 12, and in another 

14 in the corresponding half.

Measurements. The dimensions can not be accurately given. The 

height of the largest specimen is about 33 mm. An apparently 

crushed and abnormally elongated specimen gives approximately: 

Height, 25 mm.; length, 29 mm.; breadth, 15 mm.

Occurrence. The species is represented by one nearly complete 

shell, two considerable portions of valves, and a few fragments; from 

locality 1^ miles east of Malone station. The shell fragment collected in 1895 by the Messrs. Goodell, and which I referred to in 

volume 5 of the Journal of Geology (p. 817) as " possibly a Trigonia 

of the section Costatse," is of this species.

ASTARTID^E. 

Genus ASTAKTE Sowerby.

jASTARTE RREVIACOLA Sp. 11. 

PI. XI, fig. 4.

Cf. Astarte microphyes Felix, 1891, Beitr. Geol. u. Pal. Mex., pt. 3, p. 179, PI. 

XXVII, fig. 31. '

The locality 1-| miles east of Malone station yielded frequent examples of this fossil. They agree fairly well with Doctor Felix's 

description of Astarte microphyes, but not with his figure. As 

regards the peculiar disposition of the ribs which is given for A. 

microphyes, the tendency to posterior angular bending is well shown 

in most specimens of the Malone Astarte, but a tendency to anterior 

angular bending is little or in some cases apparently not at all 

expressed. If the Cerro de Titania and the Malone specimens are 

referable to one and the same species, microphyes, as seems hardly 

possible, the form of that species is not quite correctly shown in the 

original figure, as the anterior part of the dorsal line, instead of 

sloping like the posterior part, is strongly excavated just in front of 

the beaks in all of the Malone specimens in which this part of the
CRAGIN.] DESCRIPTIONS OF SPECIES. 65

shell is shown. The triangular-ovate to quinquelateral outline presents dorsally a nearly straight incline back of the beaks and is 

strongly excavated in front of them; has a long, gently convex base, 

and is posteriorly or infero-posteriorly truncate, and narrowly 

rounded anteriorly. The shell is quite strongly compressed, and the 

ribs of either valve reach 11 in number. The ribs are coarse, strongly 

elevated, gently compressed, and separated by round-bottomed intervals a little wider than themselves. Of more than GO specimens 

collected from east of Malone, a single one, among the young examples, is quite ventricose, gapes slightly in the interval between two of 

the subdistal ribs, and exposes there a double and interlocking set of 

strong denticles like those of the internal margins of the adult shell.

Measurements. The specimen figured has the following dimensions : Height, 10 mm.; length, 14 mm.; breadth, 4 mm. In less 

perfect examples a height of 12 mm. and a length of 16 mm. are indicated.

ASTARTE MALONENSIS Oagin.

PI. XI, figs. 10, H; PI. XII, figs. 1-3.

Venus malonensis Cragin, 1893, Fourth Ann. Kept. Geol. Survey Texas, pt. 

2, p. 216, PI. XXXV, figs. 1 and 2; and Jour. Geol., vol. 5, p. 817.

Shell rather large, thick-valved, moderately ventricose, or sometimes slightly compressed, inequilateral, broadly and variably subovate; the dorsal side flattish-convex behind the beaks and excavated 

in advance of them; the anterior side rounded or slightly subtruncate 

from being a little prominent in its upper part; the posterior side 

rather narrowly convex; the base broadly convex; beaks only moderately elevated, approximate, their summits varying from subcentral 

to a position just back of the anterior third; lunule and escutcheon 

deeply and abruptly impressed, especially the former, which is narrow-cordate; cardinal teeth 2-2, unstriated, the central of the right 

valve being much larger than the anterior and the posterior of the 

left valve being larger than the central; ° a posterior remote, horizontal, pliciform lateral tooth in either valve fitting into a corresponding groove in the other; pallial line sinuate, its impress on the 

best-preserved casts crossed by faint.radial.plications; pallial sinus 

ample, its anterior and posterior limbs, respectively, subvertical and 

subhorizontal (the latter a little ascending), its fundus obtuse; Active 

margins crenulated within; shell ornamented with numerous subequal 

to unequal concentric, coarsely linear pliciform growth lines, whose 

sequence is usually interrupted by remote and more elevated folds.

" The cardinal teeth are here regarded as 3 in each valve, but with 1 in each valve 

obsolete.

. 266 05 M 5
66 MALONE JUEASSIC FOBMATION OF TEXAS. [BULL. 26G.

imbrications, or constrictions that tend to mark off the surface into 

regular stages.

Measurements. The type measurements height, 72 mm.; length, 

83 mm.; breadth, 55 mm. are those of a rotund-ovate example. The 

height is often somewhat less in proportion to the length. Adult 

specimens of average inflation have the breadth equal to about twothirds of the height. The maximum known size is indicated by an 

imperfect specimen, which has a height of 79 mm.

Occurrence. This is one of the commonest and most conspicuous 

of the fossils of the Malone formation. It ranges through all of the 

fossiliferous part of the Theta subdivision that is exposed in the 

Malone hills, occurring not only at the principal collecting ground, a 

mile and a half east of Malone station, but also west of the Trio. 

About 90 specimens were collected at the former locality. Examples 

were obtained from the west side of the north end of Malone Mountain, at the same horizon and locality that yielded the specimens of 

Nautilus; from the first high ridge west of Malone Mountain, about 2 

miles west of Malone station, and from a locality about 1 mile east of 

Finlay station. A probable example was obtained by Doctor Stanton 

from the western foothills, 2 miles north of the southern end.of Malone 

Mountain, and a distorted one was found by me on the anticline in 

the east side of the mountain, about a mile from its southern end.

Rotund-ovate, transverse-ovate, and oblique or rhombic-ovate are 

all more or less closely approached by the lateral profile of this shell 

as preserved, which also in some cases is nearly equilateral. A part 

of this variation, but evidently not all of it, is to be attributed to the 

dynamical stresses to which the Malone rocks have been subjected. 

In young examples the form is usually more oblong, less equilateral, 

and less compressed, and the concentric ribbing becomes more pronounced and regular, approaching the type of ornamentation commonly seen in medium-sized and small species of Astarte.

The species seems to be sufficiently near the Jurassic section, Ccelastarte, of B6hm.a It differs from Astarte excavata Sby., the best 

known representative of that section, in being less strongly inequilateral and in having none of the cardinal teeth striated. The central 

cardinal of the right valve, while it is the largest tooth of the shell, 

is relatively smaller than that "of A. excavata as figured by Bohm. 

In form it approaches the sinupalliate species Asta.rte neocomiensix 

d'Orb, from which it differs by hinge details and its crenulated 

margins.

Stoliczka h observes:

« Ccelastarte und Heteropis, Ber. Naturf. Ges. Freiburg, i. B. Bd. 7, 1893, pp. 1(59-17*.

ri. vni.

6 Cret. Pelecypoda of Southern India, p. 285. Memoirs of the Geological Survey of 

India. 1'alaeontologia Indica, vol. 3, Calcutta, 1871.
CIIAGIN.] , . DESCRIPTIONS OF SPECIES. ' 67

Eriphyla especially seems to be largely represented among the fossil Astarte, 

as recorded at the present time, and probably all the species which have an 

indication of a posterior pallial sinus belong to the former genus. They can 

scarcely be referred to Astarte, for the single anal opening which the animal 

of this last possesses lies behind the posterior muscular scar, but not below it, 

where the formation of a sinus, if present, must be due to the development of 

muscles supporting a branchial siphon, or at least a special branchial opening. 

Neither of these are, however, present in Astarte.

But so gradual is the transition from none to a well-marked pallial 

sinus that it seems impossible in practice to distinguish Eriphyla from 

Astarte clearly by this criterion.

ASTARTE POSTICALVA sp. n. 

PI. XI, figs. 5, 6.

Shell small, thin, triangular-ovate, of intermediate convexity;

beaks rather prominent and pointed, directed somewhat forward, 

anteriorly excavated, placed near and usually back of the limit of the 

anterior third; posterior slope a little flattened; anterior threefourths (to four-fifths) of shell ornamented with numero.us linear 

concentric costellae, Avhich are separated in strong relief by deep striae 

about half as wide as themselves; the flattened posterior fourth or 

fifth forming a sort of area which is plain, or marked with ordinary 

growth lines only, and is separated from the preiireal surface by a 

very obtuse or rounded radial angulation which is not of itself a discrete and salient feature, but consists merely of the rather abruptly 

curved transition from" the outer to the flattened posterior slope of 

the shell. The costellse are deflected at their posterior ends, vanishing rather rapidly, but not abruptly, as they approach the plain area.

Measurements. Height, 13 mm.; length, 15 mm.; breadth, 10 mm. 

A valve of another specimen has a, height of about 14 mm. and a 

length of 17 mm.

Occurrence. Not infrequent 1£ miles east of Malone station. 

Twenty-one specimens were collected.

ASTARTE? ISODOKTOIDES sp. n. 

Fl. X.I, figs. 8, 9.

Shell small, gibbous, inequilateral, oblong-ovate, the dorsal line 

gently declivous and slightly convex back of the beaks and very 

feebly excavated in front of them: base nearly straight; anterior 

side rounded; posterior side obliquely truncated; beaks low, in con-- 

tact, situated near the anterior third, an obtuse umbonal ridge or 

inflation extending from their summits to the postero-ventral margin, 

and the greatest breadth of the shell being, by reason of such infla-
63 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

lion, near the anterior limit of the posterior third; flanks and postumbonal slopes more or less flattened; ligament external, short; surface of shell concentrically striate, or ornamented with numerous 

strong linear elevations whose development varies, and is more regular on the proximal part of the shell, while on the distal part there 

are one or two excavated zones bounded by high lines. The lines run 

nearly straight for a considerable part of their course parallel to the 

base, turning upward more shortly at the posterior" than at the anterior end of it.

Measurements. Height, 13 mm.; length (restored), about 18mm.; 

breadth, 10 mm. . 

Occurrence. A mile and a half east of Malone station. Only 1 

specimen of the typical form was obtained. Of 3 others believed to 

be only young and compressed examples of the species, 2 are more 

or less complete right valves, 1 of which shows a ligamental groove 

and a strongly denticulated inner margin; and the third is a shell 

quite flattened out. All three of these young examples agree with 

the proximal and differ from the distal part of the type shell in having a tendency to a rather uniform and close development of the concentric linear costellze.

The specific name refers to some resemblance which the shell presents in form to that of Isodonta, as represented by the type of tha. 

genus, 7. deshayesii Buv.

ASTAKTE? CRATICULA Sp. n. 

PI. XI, fig. 7.

Shell small, rather ventricose, subovate, strongly depressed along 

a narrow zone near the posterior cardinal border from the beaks to

the posterior extremity; beaks well inflated, moderately elevated, 

placed somewhat in advance of the middle and back of the anterior 

third; postero-dorsal flattened area separated from the rest of the 

shell by a radial angulation and itself divided into two concave 

zones by a radial cariniform angulation; the general surface of the 

valves ornamented rather closely with regular, blunt-topped, concentric costellae, which are in strong relief and separated by intervals 

of about their own width. The ornamentation of this shell recalls 

the genus Trigonia.

Measurements. Estimated measurements only can be given, the 

margins of both valves of the type being imperfect. The apparent 

approximate dimensions are: Height, 22 mm.; length, 28 mm.; 

breadth, 17 mm.

Occurrence. The only specimen obtained is from the locality 1^ 

miles east of Malone station.
CRAGIN.] DESCRIPTIONS OF SPECIES. . 69

CRASSATELLID^E.

Genus PTYCHOMYA Agassiz.

PTYCHOMYA STANTONI sp. n.

PI. XII, figs. 4-6.

Shell small, compressed, cuneate-ovate or trapezoid-ovate, a little 

excavated at the front of the beaks; the anterior side short, rounded; 

the posterior side long; the dorsal margin having a gentle and nearly 

straight descent back of the beaks for a considerable distance and 

then declining more rapidly, so that the posterior side of the shell 

is obliquely truncate above; the base nearly straight in its median 

and major portion; the posterior urnbonal slope forming with the 

outer slope a gentle shoulder;,valves thick, their margins crenulated 

within; beaks very little salient; lumile cuneate-lanceolate, deeply 

excavated; surface ornamented with a considerable number of I'ibs 

which form an anterior nearly vertical series of up\vardly directed 

chevrons below the beaks, and a posterior oblique series of nearly 

closed, distally directed angles whose apices lie on the umbonal 

shoulder; on the posterior part of the shell the ribs pursue a nearly 

straight course backward and downward to the basal and posterior 

margins, though arranged in two converging sets, in each of which 

the}' are slightly-divergent; on the anterior region they are subhorizontal, curved for Avar d and upward, and often minutely undulated 

or zigzagged. The sides of the subumbonal chevrons, exclusive of 

the part that forms the usually more or less cuspidate apex, diverge 

at an angle which is right or sometimes slightly acute in the earlier 

ribs and becomes quite obtuse in the later ones. The ribs are generally linear-compressed and separated by broader concave intervals,, 

but in occasional specimens, and especially on the posterior region, are 

more obtuse, with the intervals equaling or distally exceeding them.

Measurements. A nearly complete right valve indicates: Height, 

16.5 mm.; length, 31 mm.; breadth, 8 or 9 mm. An internal cast of 

a right valve gives: Height, 18 mm.; length, 32 mm.

Occurrence. Twenty-three specimens, in part only fragments, with 

the characteristic ornamentation, are in hand. All are from the 

locality 1| miles east of Malone station, and most, if not all, from the 

lower part of the Theta beds there outcropping.

In pattern of ornamentation and in size Ptychomya stantoni comes 

nearest to Pt. complicata Tate, from which it differs in having the 

beaks less anteriorly placed and the posterior truncation very oblique 

instead of nearly square; the position of the beaks and the line of 

chevrons below them is as in Pt. koeneni Behrendsen. The general 

form has some resemblance to the latter species, but its lateral profiledeparts more from a regular oval and tends toward a cuneate. It
70 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

differs from Pt. koeneni also by its much smaller size, and in the 

absence of small downward-pointing chevrons-at the apices of the 

middle and lower of the large upward-pointing ones.

The species is named after Doctor Stanton, who first recognized 

its genus on seeing it in my collection at Sierra Blanca, Tex., he 

having previously ascertained ' that Pholadomya ragsdalei Nobis 

belongs also to Ptychomya. Doctor Stanton has recently shown me 

two casts of the latter species on which the hinge characters of the 

left valve, as described and figured by Pictet and Campiche,0 are well 

displayed.

The Ptychomya} hitherto described, so far as known to me at this 

time (1899), are as folknvs:

Ptychomya rolnnaMina, (cl'Orbigny), 1843, Pal. Fr., Terr. Cret, vol. 3, p. 75, pi.

264, figs. 10-13. 

Ptychomya .solita (d'Orhigny), 1851, Rev. et Mag. de Zool., 2d series, vol. 3,

p. 381, pi. 10, figs. 3, 4. 

Ptychomya sp. Unnamed. Described and figured, 1857, by Pictet and Renevier in Pal. Suisse, Terr. Aptien de'la Perte du Rhone, et Ste. Croix, p. 90,

pi. 11, figs. 2a, 2b, 3a, 3b, as of Pt. rolrinaldina (d'Orb.), but removed from

the latter by Pictet and Campiche in 1860 (Pal. Suisse, Foss. Terr. Cret.

Ste. Croix, p. 357), and placed near PL neocomiensis (de Loriol) either as

a variety of the latter or a distinct species. 

Ptychomya buchiana (Karsten), 1858, Geognost. Verbaltn. des Westl. Columb.,

Bericht 32 ste Versamml. Deutsch. Naturf. u. Artec, p. 113, PI. V, figs. 7a, 7b. 

Ptychomya neocomiensis (de Loriol), 1861, Descr. des Anim. Foss. du Mont

Sal&ve, p. 71, pi.. 9, figs. 1-4. 

Ptychomya dosdalea Coquand, 1866, Mon. Pal. de 1'Rtage Aptien de 1'Espagne,

p. 127, PI. XX, figs. 1, 2. 

Ptychomya germani Pictet and Campiche, 1866, Pal. Suisse, Terr. Cret. de Ste.

Croix, p. 354, PL CXXVII, figs. 7, 8. 

Ptychomya complicata (Tate), 1867, Quart. Jour. Geol. Soc. London, vol. 23, Pt.

I, p. 160, PI. IX, fig. 8. 

.Ptychomya zitteli Dames, 1S73, Zeitschr. Deutsch. Geol. Gesellsch., vol. 25, p

380, PI. XII, figs, l, 2. 

Ptychomya. sp. Unnamed. Described and figured, 1882, by Franz Toula in

Deukschr. Kais. Akad. Wissensch. Mat-Nat. Cl., B<1. XLIV, 2te Abth., p.

35, PI. IV, fig. 38. Regarded by Toula as probably identical with Pt.

neocomiensis, though he notes differences. It seems to me to be separated

by its strongly arched principal costte and dorsal border, as well as by its

size. 

Ptychomya koeneni P>ehrendsen, 1892. Zeitschr. Deutsch. Geol. Geselsch., vol.

44, p. 23, PI. II, fig. 4, and pi. 3, figs. 8a. Sb.

Ptychomya ragsdalei (Cragin), 1895, Colorado College Studies. V, p. 58.

 . 

In addition to the above, a species of Ptychomya has been reported

by G. Steinmann b as occurring in the Cordilleras at Chilian, Chile, 

possibly in the same bed with Trigonia transUoria Steinmann. This 

Triffonia occurs also at Caracoles, Bolivia, from an unknown horizon O ' . f

°Pal. Suisse, Terr. Cret. de Ste. Croix, p. 351, PI. CXXVII, figs. 9d, 9e. 

" Neues Jahrbuch f. Min., etc., 1882, vol. 1, p. 224.
CUAGIN.] DESCRIPTIONS OF SPECIES. 71

that, on the ground of the kind of rock attached to the specimen, 

Professor Steinmarm regards as probably Lower Cretaceous, though 

nearly all of the Mesozoic fossils that he lists from Caracoles he considers Jurassic. I am not aware that the Chilian Ptychomya has 

been specifically named or described.

The orbiciilar, toothless, divaricately ornamented shell described 

by Lycett a as Ptychomya? agassizii, and the elongate Pandora? 

(equivalvis Deshayes 6 and Crassatella cornueliana d'0rb. c which have 

been referred to Ptychomya by some paleontologists, are here, following Stpliczka,'1 excluded from the genus.

The size of the shell in Ptychomya seems to have been less in the 

earlier history of the genus and to have reached its maximum in the 

Gault. The relation of size to time is indicated in the following table, 

in which an attempt has been made to group the species roughly in accordance AA7 ith their relative geological position, known or supposed:

Table showing sizes of species of Ptychomya at various geological epochs.

Species.

zitteli -------

ragsdalei

buchiana ....

dsedalea _ -.- .

(Unnamed) .

solita --.---.

(Unnamed) . 

neocomiensis

koeneni

robinaldina - 

germani. ....

complicata . . 

stantoni ......

Length.

mm.

90

105

120

110

80:

80

67 

60

57

35 

40

31.7 

32

Geological position.

Turonian ...................... ....

Gault...... .................... ....

Aptian. .................... .......

Aptian. .................. ...:......

(? Upper part of) Lower Cretaceous.

Uppermost Neocomian (probably 

fideToula).

Lower and middle Neocomian ......

Neocomian e .......................

Lower and middle Neocomian/- .... 

Lower Neocomian ( Valangian) .....

Lower Neocomian? (Jurassic?) ....... 

Malone ...--.---....-.--.---..-..

Locality.

Western Alps.

Northern Texas.

United States of Colombia. 

'Spain.

Switzerland.

United States of Colombia. 

Western Balkans.

France, Switzerland.

Argentine Cordilleras.

France, Switzerland, 

England.

St. Croix, Switzerland.

Cape of Good Hope. 

Southwestern Texas.

" Proc. Cotteswold Naturalists' Club, vol. 1, p. 69, I'l. If, figs. 6, 6a.

6 Mem. Soc. Geol. de Prance, vol. 5, p. 4, pi. 3, figs. 7a, 7b.

" Pal. fr., Terr. Crfit., vol. 3, p. 74, pi. 264, figs. 7-9.

A See Cret. Fauna Southern India, vol. 3, p. 294:

8 Behrensden compares liis species, with the lower and middle Neocomian species, 

germani and rolinaldina.

f Morris and E. Forbes have recorded this species from the lower Greensand ; but 

these records are early ones (1845 and 1854) and not improbably refer to Pt. neocomicnsis, which was not established till ,1861. A species close to Pt. neocomiensis, 'and perhaps 

not specifically distinct'from it, was referred to roMnalMna by' Pictet and Renevier as 

late as 1857 to 1866. See remarks in above list of hitherto-described Ptychomyae.
72 MALONE JURASSIC FORMATION OP TEXAS. . [BULL. 266.

LIJCINID^E.

Genus LUCINA Brug.

LC/CINA POTOSINA C. and A.

PI. XIII, figs. 4, 5.

Lucina potosina Castillo and Aguilera, 1895, Bol. Com. Geoi. Mex., No. 1. 

p. 6, PI. IV, figs. 2, 3, and 6; and PL V, figs. 11 to 14.

Five specimens from the locality 1£ miles east of Malone station 

seem to agree sufficiently well in size and form with the small, transverse and rather inflated Sierra de Catorce shells that constitute the 

type variety of Lucina potosina.

The following is a translation of Castillo and Aguilera's description of the species:

SJiell transversely oval, relatively compressed, inequilateral. Buccal region 

longer than the anal, uniformly rounded at its extremity and nearly of the same 

width as the anal. Lunule well developed, rather deep and generally wider in 

the right valve. Anal region nearly of the same breadth as the buccal, rounded 

at its extremity, more inflated than the buccal region. Ligamental area narrow, 

deep, and elongated, occupying the whole length of the anal region. Cardinal 

border slightly concave on the buccal side and straight or gently convex on the 

anal side. Umbones subcentral, contiguous, and a little inclined to the buccal 

side. Ventral or lower border little curved, joined to the anterior and posterior 

borders by arcs of more pronounced curve than its general curvature. Flanks 

convex, more inflated below the beaks where the major convexity is found; this 

diminishes gradually toward the borders. Surface adorned with delicate concentric costella?, little salient and separated by plain intervals four to six times 

wider than the costellfe. Length, 19, 20.5, 21 mm.; breadth, in relation to the 

length, 0.79, 0.80, 0.85; thickness, in relation to the length, 0.47, '0.48, 0.48.

The exact geological position of Lucina potosina at its type locality 

is not known, as the records are somewhat conflicting. Castillo and 

Aguilera state, on page 8 of the above-cited bulletin, that the types

of this species and of Cyprina coteroi were found associated with

Alamitos fossils, but were petrified in flint, believed to have been derived from the flint-bearing limestones of their " grupo superior," that 

overlie the sandstones of the Cieneguita (Lower Cretaceous) as the 

Cieneguita in turn overlies the Alamitos (Upper Jurassic). On page 

-1-9 of the same they omit Cyprina coteroi, but include Lucina potosina 

in the list of fossils of the grupo superior, and state that Schloenbacliia 

af. inftata is the only fossil found in the limestones of the grupo 

superior, ascribing Lucina potosina and the other fossils of the grupo 

superior to calcareous and marly shale below the limestone, in the 

base of the grupo. Finally, on page 50, Cyprina coteroi is given as 

one of the fossils of the Alamitos beds, which are Upper Jurassic. 

In view of the confusion that has arisen regarding the original stratigraphic source of these fossils, and the further fact that the actual 

collecting of them seems to have been from among the fossils of the 

Alamitos, there would appear v to be some uncertainty as to their
CRAGIN.] DESCEIPTJONS OF SPECIES. 73

having come from the flint-bearing limestones of the grupo superior, 

notwithstanding the flinty character of their fossilization and a possibility, at least, that both species may have come from some minor 

intercalation or segregation of siliceous matter in either the Cieneguita or the Alamitos beds.

LUCINA POTOSINA var. METRICA var n. 

Pi. XI11, figs. 6-10.

Lucina metrica Cragin, 1898, Jour. Geol., vol. 5, p. 817.

Lucina potosina ? Cragin, 1.89S, loo. cit., p. 817 (footnote) and p. 819.

Shell eqnivalve, compressed or little inflated, flattish-lenticular, 

suborbicular, yet tending somewhat to a four- or five-sided outline, 

usually a little transverse, but often not markedly so, sometimes 

aboi.it equilateral, for the most part slightly, and in exceptional cases 

considerably, inequilateral; valves thin; postero-dorsal region somewhat especially compressed in contrast with the gently inflated U1TIbonal region in front of it, the concavity here being counterbalanced 

by a feebler compression of the antero-dorsal region; beaks very 

small and depressed, subcentral, usually placed a little back of the 

middle; surface ornamented with widely and regularly interspaced, 

strongly and abruptly elevated, linear-compressed, concentric costellse. 

The spaces between the latter are about six times as wide as the 

costellse themselves, flat, marked only with numerous and fine 

croAvded, concentric growth lines; and are remarkable for the regularity of their breadth, which increases distally with almost imperceptible increments, but shows occasional variations.

Measurements.- Height, 34 mm.; length, 35 mm.; breadth, 10 mm. 

in a specimen of the commoner and intermediate size, much smaller 

specimens being similarly proportioned. For the same dimensions, 

an example of average adult size and an exceptionally large one 

give, respectively, 41, 45, 14, and 54, 59, 16 mm.

Occurrence. A mile and a half east of Malone station. One of the 

more abundant fossils there occurring, but less common than the 

Pleuromya inconstans. More than 200 specimens are represented. 

A few examples were also obtained in foothills at the northwest end of 

Malone Mountain, about 2 miles east-southeast of Finlay station, 

and west of the mountain, 2 miles north of its southern end.

The height of the shell in L. potozina, var. metrica is commonly 

from 90 to 97 per cent of the length, which, however, it may occasionally equal. The breadth averages less than 30 per cent of the length; 

in 10 measured specimens it averages 29.46, the minimum being 25.5, 

and the maximum being 32 per cent. The corresponding ratios given 

by Castillo and Aguilera for typical potosina are height as percentage of length 0.79 to 0.85, and breadth as percentage of length 0.47 

to 0.48.
74 MALONE JURASSIC FOBMATION OF TEXAS. [BULL. 266.

From all of the data above given it is seen that the shell of var. 

metrica attains a much larger size than that of var. potosina, is considerably less inflated, and has a less transverse (i. e., more elevated) 

and more nearly equilateral contour.

Lucina potosina, var. metrica is not onry a pronounced variety of 

its species but it is the largely preponderating representative both of 

its species and of its genus in the Upper Jurassic of western Texas.

As is usually found to be the case where very large numbers of a 

species of fossil are available for study, L. potosina presents considerable individual variation. Seven or eight specimens from locality 1-| miles east of Malone, represent a third variety of the species, 

which is apparently onh7 an individual phase, though rather a striking one, of var. metrica. They show the following characters: The 

shell is about as large as the largest examples of the ordinary form of 

metrica; transversely broad-oval, inclining to subquadrate; inequir 

lateral; inflated throughout, though unequally so, the valves being 

radially warped or flexuous, and especially swollen on the umbonal 

slope, on either side of which are two broad and shallow concave 

radial zones, the anterior one of which passes downward and the posterior one downward and backward; a second and smaller convex 

radial zone being developed in front of the anterior concave one. The 

beaks are more inflated than those of- the typical form of var. metrica. 

The basal margin of the shell is a little prominent and receding 

opposite the convex and concave zones, respectively. Corresponding 

with the general contour of the shell, the concentric linear costellae, 

which in the common phase of var. metrica, have an almost uniform 

downward convexity in the postero-basal part of their course, assume 

in this phase a nearly straight or slightly upward convex trend for a 

considerable distance in this part of their course, swinging upward 

rather suddenly anterior and posterior to it. The approximate

dimensions are: Height, 45 mm.; length, 50 mm.; breadth, 20 mm. 

This phase, then, is distinguished from the ordinary phase of var. 

metrica by its size, average adult examples of the latter being considerably smaller, by its greater and more pervasive inflation, strongly 

flexuous valves, and more transverse and inequilateral contour. ' A 

tendency toward this form is seen in some of the smaller examples of 

the other phase of metrica.

LUCINA ? EMARGINATA sp. n. 

PI. XIII,'figs 1, 2.

Cf. Cyprimeria ? mexicana Castillo and Aguilera, 1895, Bol. Coin. Geol. Mex.,. 

No. 1, p. 9, PI. V, fig. 3.

Shell suborbicular, compressed, though less so than that of Lucina 

potosina, var. 'metrica, the breadth being equal to about half of the
CRAGIN.] DESCRIPTIONS OF .SPECIES. » 75

height; anterior, ventral, and posterior sides rounded; dorsal side 

abruptly and emarginately excavated before the beaks to a point distant one-fourth of the shell length, where it joins the anterior side in 

fin obtuse angle, the posterior part of the dorsal side declining in a 

nearly straight line, with some convexity near the beaks, to a point 

two and a half times as remote, where it makes an obtuse angle with 

the posterior border; beaks low, with apex curved forward; lunule 

large, about twice as long as wide, abruptly and rather deeply impressed; margins entire; surface ornamented with rather coarse, 

rounded, subdued, concentric costellse separated by equal or narrower 

intervals, each costella making an irregular and gentle undulatory 

flexure as it approaches the posterior part of the dorsal margin.

Measurements. In an accidentally somewhat compressed specimen, 

height, 21 mm.; length, 22 mm.; breadth, 7 mm. In a second example, height, 20 mm.; length, 19 mm.; breadth, 10 mm. In a third, 

height, 32 mm.; length, 30.5 mm.: breadth about 16 mm.

Occurrence. Three examples were obtained from the locality 1^ 

miles east of Malone station.

In the absence of a satisfactory knowledge of the hinge details, 

the species is here placed in the genus Lucina because of the abruptly 

excavated and rather deep lunule, the lunule in Cyprimeria being 

feebly excavated or lacking.

LUCINA PLANIUSCULA sp. n.

PI. XIII, fig. 3.

Shell of intermediate size for Lucina, thick-valved, broadly suboval, rather inflated, the breadth equal to more than half of the 

height, height equaling about five-sixths of the length, moderately 

inequilateral, the posterior side being between three-fourths and fourfifths as long as the anterior, the latter but little contracted; beaks 

little prominent; surface nearly plain, ornamented with inconspicu^ 

ous, concentric raised lines and strifje, which on the major part of the 

surface are more or less obsolete, but are more distinct on the anterior 

and posterior marginal regions, the raised lines on the latter being 

very fine and intervaled on the upper part, becoming coarser and 

more crowded below.

Measurements. Height, 26.5 mm.; length, 31 mm.; breadth, 15 

mm,; in another example, height, 28 mm.; length, 31 mm.

Occurrence. Four shells and about a dozen casts of this fossil 

were collected in foothills in the northwest end of Malone Mountain, 

about 2 miles east-southeast of Finlay station.

From Lucina coetoi C. and A., the L. planiuscula appears to differ 

chiefly by its more strongly inflated and much less strongly inequilateral shell and its plainer ornamentation.
76 MALONE JURASSIC FORMATION OF TEXAS. [.BULL. 26G.

Genus UNICARDIUM d'Orbigny.

UNICARDIUM ? SEMIROTUNDUM sp. n.

PI. XITS figs. 9-11.

Shell thin, pyramido-suborbicular, moderately inequilateral, well 

inflated, the height nearly equal to the length; beaks large and prominent, pyramidal, submedian, placed a little nearer to the anterior 

than to the posterior extremity, curved inward and slightly forward, 

so that the anterior cardinal border is more concave than the posterior; anterior and posterior borders rather short; base evenly and 

rather broadly rounded; surface marked only-with, fine concentric 

growth lines, most of Avhich are rather feebly, a few more strongly, 

impressed.

Measurements. Height, 21 mm.; length, 22 mm.; breadth, 13 mm. 

Height in another nearly like-proportioned example about 25 mm.

Occurrence. Twelve specimens were collected by Doctor Stanton 

at the following four localities: A mile and a half east of Malone 

station ; anticline in east base of Malone Mountain about 1 mile north 

of its southern end; west of Malone Mountain, nearly 2 miles south 

of Avest from Malone station, in No. 13 of his Malone Mountain 

section; and in foothills at the northwestern end of Malone Mountain, 

a little over 2 miles east-southeast of Finlay station, here also apparently in No. 13. Four examples were also collected by me at the 

first of the localities above named.

The species shows some resemblance in form to U. varicosum, Sowerby, but has larger and more elevated umbones and, for the body of 

the valves, a more rotund contour.

UNICARDIUM ? TRANSVERSUM sp. n.

PI. XII, figs. 7, 8.

Shell thin, well inflated, transversely subovate, the height equaling 

0.77 to 0.87 of the length; the posterior moiety of" the shell narrower and considerably longer than the anterior, and the anterior 

part of the cardinal border more concave than the posterior; base 

broadly and unequally rounded; beaks prominent, yet less so than 

those of Unicardium semirotunclum, in contact; surface smooth, 

marked only with fine concentric growth lines, which disappear under 

slight weathering. While the form of the shell is persistently transverse or subovate, the position of the beaks is widely variable, as 

shown by the umbonal fractions below, in which the numerator and 

denominator, respectively, denote the distances in millimeters of the 

umbonal summits from the anterior and posterior ends of the shell 

in four specimens selected at random. That this variability, how-
CHAGIN.] DESCRIPTIONS OF SPECIES. 77

ever, is in part due to the erogenic movements which the matrix has 

undergone is indicated both by other variation in the form and by the 

discrepancy sometimes shown in the relative position of the two beaks 

of a single shell.

Measurements. Height, 26 mm.; length, 34 mm.; breadth, 21 mm. 

Same dimensions from a left valve, respectively; height, 24 mm.; 

length, 29.5 mm.; breadth (by doubling the convexity of one valve), 

15 mm. Umbonal fractions, fj|, ff, {$, }-§. 

Occurrence. Fourteen specimens were collected from the locality 

H miles east of Malone station; one from the anticline on the eastern 

slope of Malone Mountain nearly 1 mile north of the southern end; 

and one also upward of 1 mile east of Fihlay station.

OYPRINID^E.

Genus CYPKINA Lamarck.

CYPRINA COTEROI C. and A.

PI. XIII, tigs. 11, 12.

Cyprina (Venilia) ccteroi, Cnstillo :ind Aguilera, 1895, Bol. Com. Geol. Mex.. 

No. 1, p. 8, PI. V, figs. 4 to 10.

Shell thin, triangular-ovate, inequilateral, ventricose, the height 

generally equaling one and a third to nearly one and a half times * 

the breadth and about seven-eighths of the length; posterior slope 

flattened and separated from the rest of the shell by a low crest, or 

angulation, which runs from the posterior side of the beaks to the 

somewhat pointed infero-posterior end of the shell; beaks situated 

between the middle and the anterior third, strongly inflated, high 

arched, pyramidal, incurved, somewhat anteriorly deflected, and 

nearly, if not quite, in contact; pallial line entire; general surface 

ornamented with ordinary concentric growth lines and at remote 

intervals with resting stages marked by moderate imbrication and 

groove, which descend across the posterior flattened area and turn 

suddenly forward at the posterior angulation.

Measurements. Height, 34 mm.; length, 41 mm.; breadth, 27 

mm.

Occurrence. Four (and two doubtful) specimens, from locality 1^ 

miles east of Malone station.

There is some doubt as to the true horizon of the type specimens of 

this fossil. See : remarks as to same on page 72, under Lucina 

potosina.
78 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

CYPRINA? STEEERUVITZII Cragin. 

Pi. xiv, figs. 1, 2; PI. xv, fig. l.

Cyprina (Roudairia?) streeruvitzii Cragin, 1893, Fourth Ann. Kept. Geol. 

Survey Texas, pt. 2, p. 180, PI. XXXVI, figs. 3 to 5, and PI. XL, fig 2.

Cyprina streeruvitzii has been found only in the Theta, and can 

hardly be called an abundant fossil. Notwithstanding its large size 

and the fact that special search was made for it at its type locality, 

H miles east of Malone station, the most prolific lamellibranch field 

known in the Malone formation, only 11 incomplete specimens and 

casts were found, and none of these is as good as the specimen collected there by Mr. Wyschetzki, the topographer of Mr. Yon Streeruwitz's party, in 1890. They were all, or nearly all, obtained from 

the west slope of the Truncate mound.

They add little to our. knowledge of the species.

The cast, owing to its narrow, veiy elevated, and strongly arched 

beaks, bears considerable resemblance to that of Cyprina texana 

Conrad. Its posterior area is outwardly bounded by an obtusely 

compressed, prominent ridge, interior to which is a round -bottomed 

sulcus, followed by another radial elevation and depression within. 

The casts of the anterior adductor scar are exceedingly prominent. 

An undersized though apparently normally proportioned cast has 

the height 73 mm.; breadth, "64 mm., and length approximately 

80 mm. The largest example of the shell has the beaks .broken OA^, 

but has a length of about 124 mm. Another specimen of the shell 

presents a height of about 106 mm.

Attached to some of the specimens by the stony matrix are characteristic parts of Trigonia vyschetzldi, T. proscabra, Lima intcrlinecita, Astdrte bremacola, Mytilus nuntius, Serpula gordialis, and 

other fossils.

There remains some doubt as to the genus of this shell, as the 

hinge characters have not been observed. The following is the 

original description of the species:

Shell large, triangular, the anterior and posterior sides of the outline being 

subdirect, the basal convex, height and length of shell about equal, exceeding 

the breadth; beaks prominent, situated somewhat in advance of the middle, 

posteriorly flattened or concave, their summits turned inward and forward 

till tangent or subtangent above the downward, outward, and backward curled 

apices, the latter overhanging a large and deeply impressed heart-shaped 

lunule, which is higher than wide, and is bounded by a moderate slope, the 

margins of the valves immediately below the lunule forming no such keel as 

is seen in Cyprina roemeri, the anterior termination of the shell being, on the 

contrary, very obtuse; posterior slope in either valve bicarinate, having, in 

addition to the primary angulation which abruptly separates the discal from the 

posterior slope, a second and similar radial angulation at a position which is at
CKAOIN.] . DESCRIPTIONS OF SPECIES. 79

first about two-thirds of the distance from the primary angulation to the posterior 

shell-margin, and which at length reaches that margin at rather more than 

two-thirds of the distance from the beaks to. the distal extremity of the primary 

angulation; intercarinal area? concave, that included by the secondary carinse 

forming an escutcheon, those included between the primary and the secondary 

carinoe continuous with the posterior flattening of the . umbonal summits; 

entire exterior of the shell presenting numerous strong concentric growth 

lines and divided off on the disk into rather broad, subequal, concentric zones 

by narrow, low, and, in part, obsolescent concentric ribs. Valves thick.

Measurements. Height, SS mm.; length (approximately), 93 mm.; breadth, 

74 mm.

Genus TAPES Megerle.

TAPES? CUNEOVATUS sp. n. 

Pi. XIII, fig. 13.

Shell gently compressed, thin, cuneate-ovate ; the convex-tapered 

posterior side narrowly rounded at the end ; anterior side rounded ; 

base gently convex; dorsal margin rather abruptly excavated at 

front of beaks; breadth contained about one and a half times in 

height; height about one and a half in length; beaks placed at pos7 

terior limit of anterior third; surface finery concentric striate.

Measurements. Height, 17 mm.; length, 24.5 mm.; breadth, 10 

or 12 mm.

Occurrence. A mile and a half east of Malone station ; represented 

by a right valve complete as to form, but with the larger part of the 

shell removed by weathering, enough, however, remaining to show 

 the character of the ornamentation.

PI-IOLADOMYID^E. 

Genus PHOLADOMYA Sowerby.

PHOLADOMYA TOSTA (Cragin). 

PI. XV, figs. 2, 8.

Anatina tosta Cragin, 1S93, Fourth Ann. Kept. Geol Survey Texas, pt. 2,

p. 1P.S. 

Pholadomya tosta Cragin, 1897, Jour. Geol., vol. 5, p. 817.

Shell large among its congeners, moderately ventricose, very inequilateral, oblong, with rounded extremities and long, straight-convex 

to feebly sigmoid base, pointed-ovate in cross section; the anterior 

region short; the posterior region long and someAvhat .narroAved, its 

cardinal margin feebly concave ; beaks loAv-arched, in contact, placed 

at about a fifth (sometimes less) of the shell length from the anterior 

end; entire shell presenting fine groAvth lines and irregularly interyaled, coarser, concentric imbrications, Avhich on an anterior small
80 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 206.

and a supero-posterior larger area constitute the only markings, all 

of the shell except these terminal areas being crossed by radiating 

ribs, of which there are about 20 on either valve. The ribs are narroAvly compressed arid rather strongly elevated (cariniform), often 

with irregularly crinkled summits, and some of them are pressed 

backward so that the posterior slope is comparatively gentle, while 

the anterior is steep or overhangs, giving them somewhat the appearance of imbrications; they are unequally remote and separated by 

broad, flattish-concave intervals; and one of the posterior ribs is 

usually higher and larger than the others, the two or three that are 

yet posterior to this, and a few of the anterior ribs, being less pronounced than the others. The anterior part of the base is gently 

convex, becoming straighter and gradually a little rising posterior to 

a point between the middle and the posterior end, and again apparently a little descending or prominent opposite the largest one of the 

posterior ribs, the base describing thus a feebly sigmoid curvature. 

The latter feature is not seen in all specimens, and may be due to 

mechanical distortion.

Measurements. The tAvo largest specimens average about 50 mm. 

in height. The breadth is apparently about three-fourths of the 

height, and the height about half of the length.

Occurrence. Twenty-five specimens are represented from locality 

! £ miles east of Malone station.

PHOLADOMYA MARCOUI sp. n. 

Pi. xvi; figs. 1, 2.

Shell of medium or small-medium size in its genus, very iriequilateral, short-oblong or ovate-oblong, more or less rounded at both

extremities, ventricose; posterior cardinal border slightly excavated;

the posterior region convex-cuneately compressed, gaping.narroAvly at 

the upper posterior border; beaks situated near the anterior end, elevated about as in Pholadomya Candida Sby., or P. glabra Ag.; a surface, except small anterior and posterior dorsal portions, ornamented 

with a few (about 6?) remote, feebly expressed, or obsolescent, cariniform, radial ribs, the posterior one of which is directed nearly straight 

backward (slightly downward), and also unevenly marked with 

coarse concentric growth lines.

Measurements. Height, 30 mm.; length, 50 mm.; breadth, 32 mm.

Occurrence. A mile and a half east of Malone station. This 

Pholadomya seems to be less common than either P. tosta or P. 

dumbli. Ten examples were obtained.

This or a closely related form was found with Exogyra potosina.

"Referring here to the species as presented in pis. 108 and 100 of Tryon's Structural 

and Systematic Conchology.
CEAGIN.] DESCRIPTIONS OF SPECIES. . 81

etc., at the western base of Malone Mountain, a short distance north 

of its southern end, the cast bearing indications of feeble ribs about 

as in, marcoui, but this form perhaps modified by orogenic movemerits of the matrix being longer, lower, and smaller-calibered than 

it is normally in the latter species. 

The species is named for the late Mr. Jules Marcou. }

PHOLADOMYA PAUCICOSTA Roemer? 

PI. XVI, figs. 5, 6.

Pholadornya paucicosta F. A. Roemer, 1836. Versteinerungen cles Norcldeutschen Oolithgebirges, p. 131, PI. XVI, fig. 1.

Form stout, curved-cimeate-pyriform; the umbonal region widely 

inflated transversely to the length of the shell; anterior region shortened almost back to the large, prominently elevated, tangent umbones, 

which are thus made almost terminal; the anterior margin slightly 

gaping; posterior region widened in the median plane, compressed, 

most strongly so in the upper part, which tends to a keel-like form 

and gapes considerably; base drawn upward rapidly in the anterior 

part, so that, in connection with the very salient beaks, the whole 

anterior (including umbonal) moiety of the shell has an upturned 

appearance; surface ornamented with coarse, unequal, concentric, 

costelliform growth plications and furrows and apparently with 4 

or 5 low folds radiating from the beaks forward and downward to 

the basal margin.

Measurements. The dimensions can be given only roughly. They 

appear to average, for the larger specimens: Height, 52 mm.; length, 

61 mm.; breadth, 48 mm.

Occurrence. Not rare in the Malone Hills, a mile and a half east 

of Malone station. Among 26 specimens there collected the mechanical distortion has been such that no two are quite alike. There is, 

however, a central phase about which they are grouped and to which 

several of them closely approximate, affording a sufficient!}- correct 

idea of the normal form; and so different is the shell from any other 

found in these beds that it can be recognized in any of its false shapes, 

though the radial markings are rarely well preserved and often not 

shown at all. A specimen was obtained by Doctor Stanton near the 

railroad, about 2 miles east-southeast from Finlay station, in thenorthwestern foothills of Malone Mountain.

Accepting for the European Upper Jurassic Pholadomya paucicosta Eoemer, the wide range of specific variation indicated for it by 

Moesch," it seems impossible to separate the above-described Malone 

species from it.

a Monographic der Pholadomyen. In Abhandl. Schweiz. pal. Gesell., vo|s. 1 and 2. 

Bull. 266 05 M 6
82 MALONE JURASSIC FORMATION OF TEXAS. LBULL. 266.

PHOLADOMYA PR^EPOSITA sp. n. 

PI. XVI, figs. 3, 4.

Shell small for its genus, cuneate-oblong. arched somewhat downward, very broad across the antero<-dorsal or umbonal region, the 

breadth at least equal to the height, convex-cimeately narrowed 

toward the base and rear; anterior side rather truncate; base gently 

convex; beaks anterior, terminal, projecting forward a little beyond 

the rest of the shell, directed forward and upward, then arched 

strongly inward, the apices curved a little backward, somewhat compressed as if by gentle pressure on the anterior (or inferior) and posterior (superior) sides; surface with faint concentric markings and 

several remote, low, slender, cariniform costellse which- radiate from 

the summit of the beaks, the anterior 6 (or more) obliquely crossing 

the inferior (anterior) umbonal slope to the base. The anterior part 

of the base is sharply and even a little biconcavely compressed, and a 

limited anterior region of the shell is free from the cariniform rays.

Measurements. Height, 22 mm.; breadth, 22.5 mm. In a second 

specimen, height, 20 mm.; breadth, 20 mm. The length of these 

specimens (at least more than 31 mm.) can not be exactly given, as 

they are posteriorly broken off. A third, with only remnants of the 

shell, but nearly normal as to shape, gives, height, 20 mm.; breadth, 

20 mm.; length, 34 mm. A fourth example, too much weathered on 

the flanks to give the breadth, has a height of 24 mm., and a length 

of 43 mm.

Occurrence. Four examples from locality H miles east of Malone 

station.

Genus PLEUROMYA Agassiz.

PLEUROMYA INCONSTANS C. and A. 

PI. XVII, figs. 1-5; PI. XVIII, figs. 1-3.

Pleuromya inconstans Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., 

No. 1, p. 10, PI. V, figs. 15, 16, and PI. VI, figs. 1 to 4.

Pleuromya inconstans Cragin, 1897, Jour. Geol., vol. 5, p. 817, footnote, and 

p. 819.

Though outnumbered at many points by its associates, this is the 

most generally distributed fossil of the Malone formation. It ranges 

through the entire Theta subdivision of the Malone hills (Trio) 

section, or so much of it as is exposed at the locality li miles east of 

Malone station, whence several hundred specimens were obtained. 

It was also collected by me in the lower part of limestones overlying 

conglomerate in the anticline at the eastern base of Malone Mountain, 

about 1 mile from the southern end, and was, I believe, found in 

poorly preserved examples in the gap west of the Trio, with Trigonia
CKAGIN.] DESCRIPTIONS OF SPECIES. 83

ryschetzkii and Astarte malonensis. The material collected by Doctor 

Stanton includes part of that from the first two of these and also 

specimens from the following localities: Two miles west and also 

about the same distance south of Avest of Maloiie station (here in 

Nos. 13 and 25 of his Malone Mountain section) ; foothill west of 

Malone Mountain, 2 miles north of its southern end; and west base 

of the mountain, near its southern end.

On the anterior part of the umbonal region of this shell there 

descends to the base a zone of constriction, as if the shell, when 

plastic, had been pinched, making the valves there gently concave 

and the base a little reentrant, a feature which is often pronounced, 

though sometimes scarcely perceptible. When viewed from below, 

the base is usually seen to be twisted, presenting a more or less decided 

right-and-left sigmoid flexure. The right hinge margin overlaps the 

left. The shell gapes narrowly at the posterior end.

This fossil well sustains the reputation of the Pleuromyas for 

variability, meriting its specific name even better, if possible, in 

Texas than in Mexico. Manifold shades of form present,themselves 

some natural, others dynamical modifications of these but all seem 

to intergraduate, and the specific place of many of them becomes 

Indeterminable the moment an attempt is made to group them in 

more than one species. For this reason and because some of the specimens agree perfectly with those described and figured by Castillo 

and Aguilera from the Upper Jurassic of San Lids Potosi as Pleuromya inconstans, all are referred to that species.

The cuneate, the subcylindrical. and the Gresslya-like variations 

that have been recorded from the Sierra de Catorce, all are represented in the collections from the Malone district also. What appears 

to be the central phase for the latter district may be described as folIOAVS : The posterior terminal region of the shell is usually somewhat 

narrowed, sometimes strongly so3 and is recurved or obliquely upturned; the anterior margin descends in a convex oblique line to an 

obtusely pointed or narrowly rounded corner in which it meets the 

horizontal or often somewhat downward-deflected anterior prolongation of the base. The anterior end thus presents a " Roman-nosed,'' 

or " hook-nosed," appearance, and the shell as a whole, viewed laterally, presents a sigmoid flexure, while the basal margin presents such 

flexure whether viewed from the side or from below. This is by far 

the most abundantly represented form of the species in the Malone 

district, and it attains the largest size. That it also occurs in the 

Sierra de Catorce is indicated by Castillo and Aguilera's very excellent and comprehensive description of the species, of which a translation is here added:

Shell inequilateral, of variable form, sometimes truncate on'the anterior border, sometimes with this same border salient; the general dominant form is ovate
84 MALONB JURASSIC FORMATION OF TEXAS. [BULL. 266.

trigonal. Buccal region little developed, extremely small compared with the 

anal region; excavated below the beaks, with its extremity rounded in some individuals, in others obliquely truncated, and salient in its lower part, which is 

continuous with the ventral border forming an obtuse angle. Beaks situated 

in the anterior third of the shell, varying their position in the different individuals from 'nearly terminal to subcentral; broad, convex, sometimes presenting two obtuse keels, one on each side of the apex of the beak. Anal region very 

large, convex, or depressed, narrowed toward its extremity, which is rounded. 

Dorsal border straight or slightly concave on the anal side, considerably excavated on the buccal side. Ventral border nearly straight, feebly raised at the 

extremities, but notably more at the anal side. Flanks sometimes very convex, 

giving to the shell a cylindrical form, and sometimes depressed so that they 

make it cuneiform; the greater convexity is always in the anterior part of 

the shell and below the beaks. Surface ornamented with concentric furrows 

which contrast with the fine lines of growth. Length, 34 to 63 mm.; breadth 

with relation to the length, 0.47 to 0.64; thickness with relation to the length, 

0.31 to 0.43.

Castillo and Aguilera supplement this description with the following remarks:

We possess of this species only molds and imperfect examples, but these show 

the ornamentation of the shell and its very feeble thickness. The variation in 

the characters of this species is not limited merely to the contour and the other 

details of form of the shell, but is also manifested in the mode of occurrence of 

the shell, which is equivalve in the more convex forms and evidently, becomes 

more and more inequivalvc in so far as it reaches forms in which the right 

valve is more elevated than the left in such a manner that the dorsal, border 

before and behind the beaks passes over the dorsal border of the opposite 

valve, exactly as in the Gresslyas, to which genus these forms could be 

referred without hesitation if they were found isolated, as to some extent the 

umbonal crests of which we have spoken above would make this position of the 

shell in the genus Gresslya more proper, since the obtuse furrow which is found 

along the umbonal crests somewhat resembles the oblique furrow which the 

molds of the Gresslyas present in the right valve and which in these corresponds to the internal lamina. Fortunately we have met with abundant exampies which have permitted us to follow all the variations of the shell, forming 

a series whose extremes, taken without the intermediate forms, could without 

hesitation be referred to the genera Pleurornya and Gresslya, respectively.

PLEUROMYA INCONSTANS var. CURTA var. n.

PI. XV1IT, fig. 4; PI. XIX, figs. 1, 2.

Curieate-oblong to cuneate-ovate, much shorter than the lengths of 

Pleuromya inconstans that prevail in the Theta member of the 

Malone formation, and rather compressed; the narrowly gaping posterior region of the shell slightly recurved, obliquely truncate; anterior region closed; ventral margin gently and evenly convex; dorsal 

margin much less excavated before the beaks than that of Pleuromya 

peregrina d'Orbigny; beaks more nearly terminal thandn that species, 

often unequally elevated, the right being the higher, as seen in some
CRAGIN.] DESCRIPTIONS OF SPECIES. .85

species of Pleuromya and more commonly in Gresslya, the casts, however, lacking the pronounced right dorsal groove of the latter genus.

Occurrence. In the horizon of Exogyra potosina, Gervillia Cinderella, etc., at the west base of the southern part of Malone Mountain, 

and in the Theta member of the Malone Hills, 1^ miles east of Malone 

station. The types are from the former locality. At both places the 

type variety of Pleuromya inconstans as figured by Castillo and 

Aguilera also occurs, but in the former situation curta is common, 

while in the latter.it is rare.

This form, so far as is indicated by the known material from the 

Malone Mountain locality, does not intergracluate with Pleuromya 

inconstans, and may represent a distinct species; but at the locality 

in the Malone Hills some of the forms of the multivariant inconstant 

seem to lead up to it, and it is therefore here considered a variety of 

that species. Its general proportions are not unlike those of the 

Callovian species Pleuromya peregrina d'Orb., from Avhich it is distinguished by the recurved posterior region, the position of the beaks, 

and the less decidedly excavated anterior dorsal margin.

A Gresslya-like specimen of Pleuromya from the locality east of 

Malone station, whose form resembles somewhat that of G. gr eg aria 

Goldfuss, is provisionally considered as a mechanical deformation of 

this variety, though it may be such of one of the shorter examples of 

the variety inconstans, or even be specifically distinct.

AISTATINID^E.

Genus ANATINA Lamarck.

ANATINA OBLIQUIPLICATA sp. n.

Pi. XVI, figs. 7, 8.

Shell among the smaller species of its genus, relatively compressed, 

inequilaterally elongate-oblong, rounded anteriorly, attenuated back 

of the beaks; -the gaping posterior side shorter than the large and 

closed anterior; the shell somewhat pinched or concave on the ventral part in advance of the beaks (the ventral margin a little tortuous?) ; beaks small, low, situated near-the limit of the anterior 

third; surface of the y thin valves ornamented Avith concentric growth 

lines, and on the anterior region Avith a series of coarse and prominent, 

oblique undulatory folds \vhich are nearly straight and trend about 

equally upAvard and forAvard. The folds are obtuse at summit and. 

are separated by subequivalent round-bottomed intervals; the distal 5 occupy the vahre to a distance of about 14 mm. from its anteroventral margin.
86 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

Measurements. Height, 23 mm.; length, 53 mm.; breadth, 14 mm. 

Beaks placed at 30 mm. from the anterior extremity.

Occurrence. Eight specimens from locality 1-| miles east of Malone station.

ANATINA? PLICULJFERA sp. n. 

PI. XVI, figs. 9, 10.

Shell of small medium size in the genus, oblong, anteriorly rounded, 

posteriorly truncate, strongly compressed, moderately gaping at 

anterior and posterior extremities; the posterior region relatively 

little contracted; beaks low, narrowly compressed with the shell 

itself, situated about at the posterior limit' of the anterior third of the 

shell; surface ornamented with strong, subequal, concentric plicules 

and grooves.

Measurements. Height, 29 mm.; length, 49 mm.; breadth, 14 mm.

Occurrence. A mile and a half east of Malone station. Represented by only one specimen.

There is some appearance of an anterior radial .angulation of the 

shell, directed forward and downward to the anterior extremity; but 

the condition of preservation of the type is such as makes it impossible to determine whether this is really a feature of the shell or not.

Genus THE, ACT A Leach.

THRACTA? MALONIANA sp. n.

PI. XIX, fig. 6.

Shell very thin, inequilateral, compressed, commonly about the

size of Thracia incerta Agassiz," sometimes larger, inclined to be 

more posteriorly produced, or heel-like, at the lower anterior border, 

trapezoid-ovate; posterior side narrowly gaping in the upper part; 

beaks of moderate size and elevation, situated about as in th°. 

T. incerta, their posterior slope angulated; surface marked with 

parallel, moderately elevated, compressed linear, or cariniform, concentric plicules separated by partly equal and partly unequal intervals of two or three times their own width.

Measurements. Of considerably the largest example, height, 48 

mm.; length, about 60 mm.; breadth, about 20 mm. Of a more common size, height, 37 mm.; length, 49 mm.; breadth, 18 mm. , Occurrence. Six specimens, all casts, two of which show characteristic traces of the markings, were collected 1£ miles east of 

Malone station.

"As figured in' Zittel's Handbuch, vol. 3, fig. 186.
CRAGIN.] DESCRIPTIONS OF SPECIES. 87

/

MYID^E. 

Genus CORBULA Bruguiere.

CORBULA ? MALONIANA Sp. n. 

PI. XIX, fig. 7.

This name is provisionally proposed for a small, transversej tri 

angular-ovate, moderately ventricose cast of a right valve belonging 

apparently to this genus, but unknown as to hinge or shell, obtained 

by Doctor Stanton from the same horizon that yielded the broadly 

triangular examples of Exogyra potosina, at the west base of Malone 

Mountain, a short distance north of its southern end. The height is 

about six-tenths of the length; the posterior end is slightly produced 

or pointed; the beak is pyramidal; the pallial line is coarse and 

strongly impressed. The species should possibly be referred to 

Neaera.

Measurements. Height, 5 mm.; length, a little more than 8 mm.; 

breadth indicated for cast (that of the left valve being restored), 

about 4 mm.

PHOLADID^E.

v Genus MARTESIA Leach.

MARTESIA MALONIANA sp. n.

PL XIX, figs. 3-5.

\ 

The types of this species are two casts of compressed-conoidal

shape, with portions of the, shell, in matrix. They are straight (not 

at all arcuate) and taper rapidly from the large anterior region. The 

compression is scarcely expressed in the umbonal region, but increases 

posteriorly. The base is rectilinear. Radiating downward from 

either beak to the base are two remote, transversely striated furrows, 

.of Avhich the anterior is the wider and the posterior is the more 

(deeply impressed.

' The markings seen on the casts are apparently an index of those 

peculiar to the shell. The casts do not indicate the character of the 

raecessory plates.

Measurements. The casts measure, height, 11 mm.; breadth, 10 to 

inearly 11 mm.; length, upward of 15 mm.; the posterior extremity of 

teach being broken off.

Occurrence. Obtained by Doctor Stanton in No. 13 of his Malone 

Mountain section, on the west side of Malone Mountain, south of west 

from Malone station. Besides the types, a considerable number of 

less satisfactorily preserved casts and fragments of casts were collected in their borings in fossil wood, at the same locality.
88 MALONE JTTRASSIC FORMATION OP TEXAS. [BOLL. 266.

A cast of Martesia referred to this species, obtained at the anticline 

in the east side of Malone Mountain about 1 mile north of its southern 

end, shows a more posteriorly produced form than might be inferred 

from the above-described types, indicating that a considerable length 

has been broken off from each of the latter.

Borings presumed to have been those of Martesia were also found 

H miles east of Malone station.

GASTROPODA.

PLEUROTOMARJID^E. ~

Genus PLEUROTOMARIA Defrance.

PLEUROTOMARIA CIRCUMTRUNCA sp. n.

PI. XIX, figs. 8, 9.

Shell conical, consisting of 5 to 6 flattened or in part concave. 

whorls, the slope of spire nearly straight, that of the entire shell^ however, concave, owing to the form of the body whorl; spire acute; 

sutures lightly impressed, bordered by a low elevation above and 

below; body whorl concave above the peripheral zone, its periphery 

canaliculate-truncate, or having two low, abrupt angulations with a 

narrow, shallow-concave belt between them (and which, in the poorly 

preserved and sometimes more or less distorted specimens commonly 

found at the type locality, occasionally appears like a merely flat 

truncation) ; surface of the entire shell ornamented with fine. 

crowded, revolving raised lines, so minute as to be scarcely visible to 

the naked eye, and of which (in one of the types) there are 11 on the 

peripheral canal of the body whorl. The aspect of the peripheral 

canalicular truncation is outward and slightly downward.

Measurements. Height, 20 mm. ; breadth, 19 mm. ; angular divergence of the slopes (excluding the body whorl), 66°.

Occurrence. One and a half miles east of Malone station, in the 

lower part of the Theta subdivision of the section there exposed; with 

Delphinula stantoni, Turbo? beneclathratus, Natica williamsi, Nerita 

nodilirata, Gervillia corrugata, etc. Represented by eleven examples.

Genus TURBO Linriseus.

TCRBO ? BENECLATHRATUS Sp. n. 

PI. XIX, figs. 10, 11.

Shell rather small, turbinate-conical, composed of about 4 ventricose whorls ; spire and body Avhorl about equal in height ; body whorl
CRAGIN.] DESCRIPTIONS OF SPECIES. 89

flattened and angulated on its upper part, the flattened zone being 

rather narrow and adjacent to the suture; aperture subovate; outer 

lip thin (?) ; inner lip covered with a calcareous callus, which is so 

arched as to indicate the presence of a low fold or tooth-like protuberance below; entire surface ornamented with a regular, open latticework of narrow, strongly elevated, transverse ribs, which are crossed 

by similar but somewhat more delicate revolving ones, the points 

of Intersection being slightly protuberant to subtubercular, and the 

rectangular included intervals being gently concave and each marked 

by several raised growth lines.

Measurements. Height, 19.5 mm.; breadth, 17 mm.

Occurrence. A mile and a half east of Malone station; with 

Grypkcea mexicana, Pleurotomaria circumtrunca, Natica ivilliamsi, 

etc. Known only by a single specimen, which has the basa and the 

margin of the outer lip broken off. It is possible that specimens with 

the apertural characters well preserved might show this shell to 

belong to Purpurina.

Genus DELPHINULA Lamarck.

DELPHINULA STANTONI sp. n.

PI. XIX, figs. 12-14.

Shell rather small, conoidal-turbinate, narrowly umbilicate, consisting of 4J ventricose whorls, thick, especially in the vicinity of the 

peristome; spire about equal to the body whorl in height; aperture 

circular or nearly so; whorls rather closely ornamented with revolving lines of crowded arid small but prominent granules, each granule 

shown, when the ornamentation is well preserved, to consist of a stout 

hood-like imbrication; body whorl flattened above in a rather broad 

/one that looks upward and outward, and is externally limited by an 

angulation that is marked by a line of relatively coarse and prominent hood-like imbrications, below which, in a narrow .zone, the 

surface of the whorl is again somewhat flattened and looks outwardly, 

a second line of relatively coarse and prominent granules traversing 

the flattened upper slope of the body whorl, just below the suture. 

Between the upper and lower lines of coarse imbrications there are 

two lines of the smaller ones, and between the lower and the umbilical 

border there are nine.

Measurements. Height, 16 mm.; breadth, 13 or 14 mm.; angular 

divergence of slopes, 80°.

Occurrence. A mile and a half east of Malone station, in the lower 

exposed part of the Theta; associated with Natica williamsi, Pleurotomaria circumtrunca, Gervillia corrugata, Gryphwa mexicana, and 

many other, especially of the smaller of the Malone fossils. Five
90 MALONE JtTBASSTC FORMATION OF TEXAS. [BULL. 266.

specimens were collected, four of them by Doctor Stanton, after 

whom the species is named.

NTSRITIDJE.

Genus NEKITA Linnaeus.

NERITA NODILIRATA sp. n.

Pi. XX, tigs. 1-4.,

Shell thick, composed of 2£ to 3 whorls, its very obtuse-apexed interior cast loosely coiled and making only about a revolution and a 

half; body whorl obtusely angulated above the middle, somewhat 

concave above the angulation. and again convex above the concave 

zone; spire very small, rising but little above the body whorl; 

aperture semilunar; peristome considerably thickened below; columellar area broadly flattened and overspread with a callus; whorls 

transversely trenchant-striate. or marked with close and abruptly 

elevated transverse lines, and bearing tubercular or noded ribs; 

exposed parts of the spire whorls and the corresponding (upper) part 

of the body whorl bearing rather remote, compressed, transverse ribs, 

each of which bears 2 remote nodes (the lower node being at the locus 

of angulation in the body whorl and just above the inferior suture in 

spire whorls), these ribs continued as simple ridges across the lower 

part of the whorls in very young shells, but on the body whorl of older 

ones giving place to 4 or 5 revolving interrupted ribs or rows of low, 

elongate granules or tubercles.

Measurements. Height, 27 mm.; breadth, 30 mm.; these dimensions representing considerably less than the maximum size. The 

two largest specimens at hand, though too imperfect for exact measurement, indicate dimensions between one-third and one-half greater. ' O

Occurrence. Especially abundant, with Natica wittiamsi and other 

Gasteropoda, in lower strata of the exposed part of the Theta, between 

the Trio and the Truncate mound, being represented in my collection 

by 54 specimens.

The species belongs to the subgenus Lissochilus.

NERITA FINLAYENSIS sp. n. 

Pi. XIX, fig. 15.

General form somewhat like that of N. nodilirata, both body whorl 

and spire, however, a little more elevated; whorls few; body whorl 

with an even, obtuse, revolving angulation near the middle, the same 

being obsolete near the aperture, where the shell is almost evenly
CRAQIN.] DESCRIPTIONS' OF SPECIES. 91

rounded, and gradually becoming noticeable as it recedes from it at 

half a turn from the aperture; the same angulation apparently 

continued on the lower part of the spire whorls; base of first spire 

whorl rising abruptly from the upper margin of the body whorl, the 

suture thus being strongly indicated; surface of shell devoid of transverse (vertical) ribs or nodes, plain, crossed with finer and coarser 

growth lines.

Measurements.- Height, about 20 mm.; breadth, 18.5 mm.

Occurrence. One specimen, obtained in foothills at the northwest 

end of Malone Mountain, about 2 miles east-southeast from Finlay 

station.

NERITA PEROBLATA sp. n. 

Pi. xix, figs. ic>. 17.

Shell obliquely-depressed oval, consisting of 2 whorls; spire 

involved, or rising but feebly above the adjoining whorl border; 

body whorl rapidly increasing its centrifugal expansion with spiral 

distance from its origin, convex on its outer and lower parts, flattish 

on an upper zone which is limited below by an obsolescent spiral 

ridge; aperture semicircular; inner lip without teeth, bearing a 

thick, flat-surfaced callus; outer lip with simple acute border; surface of shell plain, presenting, besides the obsolescent spiral ridge, 

only growth lines, some of .which, more pronounced than the others 

and occurring at irregular intervals, constitute coarse constrictions and 

ridges which are conspicuous also on parts of the cast from which the 

shell has been removed. Of the outer lip in the type only the lower 

border is preserved, but this shows the simple and acute character 

above described.

Measurements. Height, 41 mm. (of which the spire occupies barely 

2) ; breadth, 44 mm.; height of aperture, 35 mm.; greatest (obliquely 

centrifugal) diameter of same, 29 mm.

Occurrence. Known only by one example, which was associated 

with Nerita nodilirata, etc., 1-| miles east of Malone station.

Max Schlosser ° comments on the Jurassic forms of this genus as 

follows, translated:

The Jurassic Neritas are distinguished from the typical by the imperfect 

(Nerita ehromatica Zitt.) or wholly obsolete toothing of the inner lip (Nerita 

zittcli, neumayri). The outer lip is always simple with cutting border. As 

the only departure from this, one observes a greater or less thickening. On 

the inner lip appears a mostly very strong, often indeed high-arched callus. 

The general habit, however, agrees so well with the recent forms that the 

erection of a new subgenus appears inadvisable.

0 Die Fauna der Kelhcimer Diceras-Kalkes : Palaeontographica, vol. 28, p. 93.
92 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

TTJRJRJTELLID^E. 

Genus TURRITELLA Lamarck.

TURRITELLA BURKARTI Sp. 11. 

PI. XX, fig. 5.

Shell turreted, of moderate size for a Turritella, consisting of numerous whorls, which are .greatly convex, wider than high, and medially 

carinate by virtue of the ornamentation, bearing four granulated, 

revolving raised lines, of which one, much larger and more prominent 

than the others, and more decidedly cariniform, crosses the middle of 

the whorl, while 2 of the 3 smaller and subequal ones are placed, 

respectively, just below and just above the upper and lower limiting 

suture, the remaining one being placed between the uppermost one 

and the large carina, and nearer to the former than to the latter, so 

that the 3 intervals increase serially from uppermost to the lowermost. 

Aperture unknown.

Measurements. The type and only known specimen includes four 

largely embedded whorls within a span of 14 mm. The largest one 

of these whorls has a height of 4.5 mm. and an exposed breadth of 

5.5 mm., which is less than the true breadth, only about a third of each 

whorl being free from the matrix.

Occurrence. In the anticline on the east slope of Malone Mountain, nearly 1 mile north of its southern end; collected by Doctor 

Stanton. 

The species is named after a former traveler in Mexico, Mr. Joseph 

Burkart, who, as quoted from his "Aufenhalt und Reisen in Mexico 

in den Jahren 1825 bis 1834 " by Castillo and Aguilera, on page V of 

their Fauna Fosil, has recorded a Turritella (identified as to genus 

by Professor Goldfuss) as collected'by him in the Mineral de Catorce 

some three-quarters of a century ago. The species collected by him 

may, by no means improbably, have corresponded in geological age 

and in kind with the Malone species above briefly described.

VERMETID^E.

VERMETUS CORNEJOI Castillo and Aguilera ?. 

Pi. xx, fig. 6.

Vermetus (Burtinella) cornejoi Castillo and Aguilera, 1895, Bol. Com. 

Geol. Mex., No. 1, p. 12, PI. VI, tigs. 5, 6, and'7.

Eight specimens of Vermetus, from the Theta, 1£ miles east of 

Malone station, are referred to this species. They show only the inne^r
CRAGIN.] DESCRIPTIONS OF SPECIES. 93

whorls and only one of them approaches in size the smallest one of the 

types figured from the Sierra de Catorce by Castillo and Aguilera. 

The cavity is oval in cross section, and its lesser diameter is equal to 

about four times the thickness of its wall.

The following is a translation of the specific diagnosis:

Shell small, free in tbe adult state, tubular, inrolled planorbiform, sinistral, 

last whorl unrolled. Tube rugose, bearing two spiral carinse at the base, the 

exterior more prominent than the interior, inclosing between them a narrow 

furrow. Aperture circular or slightly oval. Surface furnished with sinuous 

growth lines and quite pronounced on the upper part of the whorls, less so on 

the inferior part.

NATICID^E. 

Genus NATICA (Adanson) Lamarck.

NATICA WILLIAMS: sp. n.

PI. XX, figs. 7, 8.

Shell of medium size in its genus, imperforate; whorls 5; spire 

small, short, and concave, giving it an apidilate aspect when well preserved, its height about one-fifth of that of the entire shell; body 

whorl large, obliquely inverted pyriform, flattish on the region below 

the weakly impressed suture, the greatest convexity being somewhat 

above the middle of the whorl; inner lip and columellar region covered with a layer of callus; aperture rather long and narrow, narrowing gradually upward, rounded below, subacute above.

Measurements. Height, 40 mm.; breadth, about 30 mm. Other 

specimens, not allowing precise measurement, indicate about one and 

a half times these dimensions.

Occurrence. A mile and a half east of Malone station, associated 

with Natica inflecta. Nerita nodilirata, etc. At this locality it is one 

of the commonest of the Malone Gastropoda. Nearly a hundred 

specimens are in hand, most of them poorly preserved owing to 

weathering.

This shell is named for Mr. John W. Williams, who in 1897 was 

prospecting in the Quitman Mountains not far from Malone, and 

whose exceedingly kind and thoughtful interest in my work, displayed in many practical ways, contributed not a little in that year to 

the pleasure as well as the success of my explorations in the Malone 

district.

In its low and concave spire and feebly impressed suture, and a tendency to greater breadth in the upper part of the body whorl, the 

shell recalls Actseonella and constitutes an unusual phase of Jurassic 

Amauropsis.
94 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

NATICA INFLECTA sp. n.

Pi. XX, tigs. 11, 12.

Shell of medium or rather small size in its genus, smaller than 

Natica williamsi, consisting of about 5 whorls, imperforate, of rather 

stout or medium elevated habit; the spire not concave, much more 

elevated than that of the above-mentioned species, its height being 

about two-fifths of that of the shell, composed of convex, well-rounded 

whorls, separated by sutures which are deeply and rather suddenly 

impressed, a narrow upper border of the whorls being gently and 

subhorizoiitally flattened; aperture narrow, or elevated, considerably 

less so, however, than that of N. williamsi, narrowly rounded below, 

obtusely pointed above; columella slightly produced, inner lip and 

spindle callus-plated; surface smooth or crossed only with ordinary 

growth lines.

'Measurements. Height, 35 mm.; breadth, 27 mm.; height of 

spire, 14 mm. A second example has dimensions about 75 per cent 

greater.

Occurrence. A mile and a half east of Malone station; with 

Natica williamsi, from which the species is readily distinguished. 

The writer obtained only three shells of N. inflecta, one of which, a 

young example, has the body whorl crossed with alternating dark and 

light bands, parallel with the growth lines. An example Avas obtained by Doctor Stanton at the same locality, and one by him in foothills at the northwest end of Malone Mountain, about 2 miles eastsoutheast from Finlay station.

The species seems to stand close to the English Oxfordian form, N. 

arguta Phil., and is referred to the subgenus Amauropsis, to which 

all of the Naticrc now known from the Malone formation seem to 

belong.

NATICA FINLAYENSIS sp. n.

PI. XX, tigs. 15, 16. '

Shell of medium size in its genus, subovate, imperforate; whorls 

about 5, moderately convex, those of the spire broad and low; body 

whorl large, elevated, oblique; spire more than a third and considerably less than half of the height of the shell, higher than the spire of 

Natica williamsi, lower than that of N. inflecta; suture much more 

strongly impressed than that of the former and much less so than that 

of the latter species; aperture elevated, arcuate-pyriform, pointed 

above, rounded below; inner lip not free-margined, and apparently 

with little callus, concave belo\v, convex above; surface plain.

Measurements. Height (approximately), 42 mm.; breadth, 

30 mm.
CRAOIN.] DESCRIPTIONS OF SPECIES. 95

Occurrence.-. The type and only, known example was obtained by 

Doctor Stanton in foothills at the northwest end of Malone Mountain, a little over 2 miles east-southeast from Finlay station.

NATICA BILAMATA sp. n. 

Pi. XX, figs, 9, 10.

Shell rather small, consisting (apparently) of about 3^ strongly 

convex whorls; without umbilicus; provided with a narrow, elongate, and shallow cleft formed by the e version of the inner lip; 

spire, short, its height much less than that of the aperture; suture 

well impressed; aperture obliquely ovate, about two-thirds as high 

as the entire shell; outer lip simple; inner lip everted, thickened 

below, its border quite free in the middle region, where it pursues a 

nearly straight course and constitutes the outer bound of the small 

umbilical cleft; exterior smooth except for the numerous ordinary 

growth lines.

Measurements. Height, about 21 ram. ; breadth 18 mm.

Occurrence. One specimen, from the same fragment of limestone 

that bore one of the types of Unicardium semirotundum 1-| miles 

east of Malone station. Collected by Doctor Stanton.

Genus PSEUDOMELANIA Pictet.

PSEUDOMELANIA GOODELLII Sp. 11. 

PI. XXI, fig. .10.

Shell large, turreted, consisting of numerous smooth, flattened. 

upwardly-imbricated whorls, of which the lower spire whorls are 

nearly twice as wide as high ; shell substance thick, sometimes showing, parallel with' the height (length) of the shell, numerous rather 

narrow, unequal, or subequal, alternating dark and light bands, of 

which there are perhaps as many as 50 of either shade on each whorl.

Measurements. Breadth of 'body whorl in largest specimen, 50 

mm. ; breadth of first spire whorl, 43 mm. ; height of same, 21 mm. 

The shell in this specimen apparently . had a height of 170 to 180 

mm. In a second example, with body whorl 44 mm. in breadth, the 

shell height is about 165 mm. . . Occurrence. This, the largest of the Gastropoda known from the 

Malone formation, is only moderately common; and all of the material of it obtained is more or less fragmentary, though collectively 

affording a fair knowledge of the species. The above description of 

it, based on all of the material now known, supersedes an earlier one 

in manuscript made by roe at a time when my knowledge of the
96 MALONE JUBASSIC FORMATION OF TEXAS. [BULL. 266.

species was derived solely from an imperfect specimen, which was 

from the locality 1| miles east of Malone station. Besides a fragment from the locality just named, Doctor Stanton's collections 

include material of this shell from the following localities : From No. 

13 (the Nautilus horizon) of his Malone Mountain section, on the 

west side of the mountain, southwesterly from Malone station; and 

from about 1 mile east of Finlay station, one of the specimens from 

the last-named locality being in rock with Trigonia calderoni. A 

poorly preserved portion of probably this fossil was also found by 

Doctor Stanton in the anticline in the eastern slope of Malone Mountain nearly 1 mile north of its southern end. 

The species is named after the late Mr. Robert W. Goodell.

Genus NERINEA Defrance.

NERINEA GOOUELLII sp. n.

PI. XXI, figs. 1-3.

Shell turriculate to cylindrical-turriculate, not exceedingly attenuate; walls thin, the outer one bearing internally one prominent, thin, 

and acute fold which extends scarcely half way across the chamber; 

columella rather slender, in part hollow, bearing 2 thin folds both 

smaller than the outer fold; whorls apparently 17 or more, low, 

usually as much as one and a half times and sometimes about twice 

as wide as high, concave, the opposed borders of successive whorls 

tending to form a low cariniform ridge with linear suture on the 

summit line, the surface of each whorl ornamented with 3 or 4 

linear, raised, revolving lines and ordinary oblique, somewhat sinuous growth lines. Of the three internal folds, the upper columellar

one, which descends from the junction of the upper wall of the 

chamber Avith the columella, is the smallest and thinnest, yet is quite 

salient.

Measurements. Breadth of largest whorls reaching 14 mm. ; angular divergence of slopes 5° or 6° to 8°.

Occurrence. Common in the limestone layers, and less so in the 

sandstone, at various levels in the Theta, 1J miles east of Malone station; exceedingly abundant in some of the lower layers. Weatheredout specimens usually occur in segments of two or three to a dozen or 

more whorls. Besides the numerous specimens in my collection, 

which include some natural longitudinal sections, I have examined 

four specimens, one of which is an artificial section, submitted by 

Doctor Stanton. Several poor weathered sections were obtained near 

the south end of Malone Mountain, from a locality which yielded 

also a specimen of Trigonia munita.
CKAGIN.] DESCRIPTIONS OF SPECIES. 97

I have not been able to ascertain the maximum height of this shell, 

nor with certainty the number of Avhorls; but in 1 specimen only 

4 mm. in breadth and about 17 mm. in height there are 15 whorls preserved, while probably 2 or 3 minute ones have been dissolved away 

at the summit.

The revolving lines of ornamentation on this shell are very delicate 

and commonly are not seen at all on weathered specimens.

In its internal ridges, as well as in the form of its whorls, the species resembles the Corallian form, N. goodhallii Sowerby.a It is 

named for the Me,ssrs R. R. and R. W. Goodell, in recognition of 

their joint exploration of the Malone, an account of which has been 

given elsewhere.

For comparison with Nerinea goodellii, Doctor Stanton has handed 

the writer some fragments and fragmental prepared sections of a Nerinea " broken from the hand specimen that bears the larger of the

types of Trigonia taffii Cragin." b These resemble A7 , goodellii superficially, but appear to lack revolving lines and to present sectional 

details which seem to refer them to a different species, although the 

unsatisfactory state of their preservation forbids full assurance that 

their internal characters are all correctly understood. In the Nerinea 

from Bluff Mesa the fold on the outer wall is relatively thicker and 

more obtuse and is altogether larger than in N. goodellii, extending a 

little more than half way across the chamber; the lower columellar 

fold is also coarser than that of N. goodellii. The upper columellar 

fold is not very clearly indicated; if present at all it is apparently 

obsolescent, or at least much smaller than that of N. goodellii.

NERINEA CIRCUMVOLUTA sp. n.

PI. XXI, figs. 4, 5.

Shell cylindrical-turriculate; walls thin, with one outer and two 

columellar folds situated as in the much more common Nerinea 

goodellii, all of the folds delicate, the outer one less so than the other 

two; columella solid, rather slender; Avhorls flat or only very slightly 

concave, one and a fourth times as high as wide, apparently at least 

as numerous as in N. goodellii, presenting an imbricated appearance 

at the suture, as if the outer wall of each whorl slightly overlapped

"Described and figured in exterior and in section by .Tames de Carle Sowerby, in Dr. 

William Henry Fitton's " Observations on some of the strata between the Chalk and the 

Oxford Oolite in the southeast of England ; " Trans. Geol. Soc. London, 2d ser., vol. 4, 

1836. Sowerby's figures (12'of PI. XXIII, loc. cit.) represent it as several times larger 

than the shell here described as (joodellii. The figures 1294 of the fourth edition of 

Dana's Manual are partial and much reduced copies of Sowerby's figures, but, unlike the 

latter, represent the shell as thick-walled.

6 The large valve from Bluff Mesa, which is the real type of this Trigonia. See remarks 

on Trigonia taffii on page 10.

Bull. 266 05 M 7
98 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

the whorl next above; suture subtended by a harroAv, plain band, 

which is itself limited below by a delicate striseform groove; surface 

ornamented only, with growth lines, which are for the most part vertical, becoming strongly recurved as they near the upper border of 

the whorl.

Measurements. A fragment 6.5 mm. wide at the lower end has 5 

whorls in a height of 29 mm.

Occurrence. The species is based on several segments collected 

and a longitudinal section prepared by Doctor Stanton-, and which 

are from the locality 1| miles east of Malone station.0

Genus NERINELLA Sharpe.

NERINELLA STANTONI sp. n.

PI. XXI, figs. G-9.

In 1898 Doctor Stanton very kindly communicated a specimen of 

Nerinella, partly cut in longitudinal section, which he had obtained 

while collecting with me duriilg the previous year from the same beds, 

1£ miles east of Malone station, that yielded Nerinea goodellii.

It is exceedingly attenuated and, within 53 mm'., includes 20 concave whorls from a number that must obviously have been much 

greater in the complete shell. The chamber has no columellar fold, 

but its outer wall presents a simple, short, and rather obtuse fold at 

about mid height. The whorls are crossed by numerous delicate 

growth lines and are ornamented with 4 equidistant, spiral, cariniform lines on the main part, besides 2 which are so close to the whorl 

borders as often to be difficultly distinguishable.

I find in nry own collection, made lijr miles east of Malone, a few

incomplete and more or less weathered specimens of this fossil. One

of these supplements Doctor Stanton's specimen as to the upper part 

of the spire, showing 16 additional whorls, with apparently a very 

few still to be added at the apex. Another represents a basal portion 

considerably broader than the larger end of Doctor Stanton's specimen, so that the number of whorls in this shell can be little, if at all. 

short of 50. The greatest breadth shown by any of these specimens 

is between 5 and 6 mm. The height of the shell is roughly estimated 

at about 100 mm.

This fossil is also recognized in material obtained by Doctor Stanton at the following places: In No. 13 of his Malone Mountain section, about 2 miles southwest of Malone station, on the west of the 

mountain; in about the same horizon something over 1 mile east of 

Finlay station, and in the anticline at the east base of the mountain, 

about a mile from its southern end.
CRAGIN.] DESCRIPTIONS OF SPECIES. 99

Genus CEEITHIUM Adanson.

CERITHIUM ARCUIFERUM sp. n.

P1..XX,1 fig. 13.

' Shell small, turriculate, many Avhorled ; spindle solid; mouth 

subquadrate; surface of the gently convex whorls ornamented with 

numerous fine revolving lines and with coarse transverse folds, or 

ribs, the latter strongly arched backward, the summit and more 

prominent portion of the arch being on the lower and more 'prominent portion of the whorls. Of the revolving lines there are about 

17 on the first spire whorl, and of the arcuate folds there are about 

the same number on the body whorl.

Measurements. Breadth, 7 mm.; angular divergence of slopes 

on the lower part of the shell, 21° or 22°.

Occurrence. A mile and a half east of Malone station; with 

Nerita nodilirata, Pleurotomaria circumtrunca, etc. Only a single 

specimen lacking the lower end of the spindle and the upper part of 

the spire has been found.

Owing to the incompleteness of the lower extremity of the shell in 

the type the basal canal is not shown, but its presence in the complete 

shell and a reference to the genus Cerithium are indicated by the character of the spindle and the general habit of the shell, the latter being 

apparently that of the subgenus Cerithinella.

ACT^EONID^E. 

Genus ACT^BONINA d'Orbigny.

ACT^ONINA ? MALONIANA Sp! n. 

PL XX, fig. 14.

Whorls 4 or 5; body whorl large, about three-fourths as wide as 

high in the cast, its sides gently convex; spire small, evidently not 

much exceeding one-fifth of the body whorl in height ; aperture 

high and narrow, somewhat broadened below, and the inner lip apparently without fold; general surface ass indicated by a preserved basal 

fragment, marked with delicate revolving grooves or striae, the striae 

separated by intervals wider than themselves.

Measurements. Height (approximately), 14.5 mm.; breadth, 

10 mm.

Occurrence. Known only by a cast bearing two fragments of the 

shell ; obtained by Doctor Stanton 1^ miles east of Malone station.
100 MALONE JURASSIC FORMATION OF TEXAS. [BULL. 266.

When viewed from above, the cast presents a somewhat squared 

form, due apparently to the accident of rock pressure.

CEPHALOPODA.

NAUTILOIDEA.

Genus NAUTILUS Breyn.

NAUTILUS BDRKARTI C. and A. ?

PI. XXII, fig. 1.

Nautilus burkarti Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., No.l, 

p. 12, PI. XXI, fig. 3.

I provisionally refer to this species an imperfect specimen of Nautilus of inflated form obtained by Doctor Stanton in No. 13 of his 

Malone Mountain section, on the west side of the -mountain southwest 

of Malone station. The dimensions are much larger than tho?e indicated by Castillo and Aguilera's figure and description of N. bwkarti, 

which are perhaps those of a young example.

The Malone Mountain specimen gives the following measurements: 

Height of shell, 123 mm.; height of last whorl, 67 mm.; breadth of the 

latter, as restored, 86 mm. The height of the last whorl is therefore 

about 54.5 per cent and its breadth about 70 per cent of the height of 

the shell, as against 55 and 64, given as corresponding percentages for 

the type-specimen.

The following is a translation of the original description of the 

species:

Shell extremely inflated; spire composed of few whorls which cover more 

than three-fourths of the wliorls preceding; flanks quite convex and attaining 

their greatest thickness near the umbilicus, whence they descend gradually 

toward the siphonal region, which is quite rounded; umbilicus narrow, deep, 

and funnel-shaped; aperture very much invaded by the spire whorl, wider than 

high, rounded on the upper part; surface nearly smooth, destitute of tubercles, 

bearing only marked growth lines, which make it slightly rough on some parts.

Diameter - - - --_- -___-_______-______ 49. 00 mm.

Breadth of the last whorl in relation to the diameter________ . 55

Thickness of the last whorl in relation to the diameter__ ______ . 64

Diameter of the umbilicus to the diameter______________ . 23

NAUTILUS NAUFRAGUS sp. n. 

 PI. XXIII, fig. 3, PI. XXIV, fig. 3.

Shell involute, somewhat compressed; volutions deeply embracing, 

increasing rapidly in size, narrowed on the feebly convex flanks from
CEAGIN.] DESCRIPTIONS OF SPECIES. 101

a region of maximum, yet moderate inflation, near the umbilicus; to 

the rather narrowly rounded periphery; septa about 24 to each turn, 

the sutures feebly waved or sigmoid; umbilicus narrow, filled with a 

shelly columella; surface of shell smooth.- The position of the 

siphuncle has not been determined.

Measurements. The greatest diameter of the larger specimen is 

about 122 mm. .The height of the largest preserved part of the bodychamber in its median plane is about 50 mm. The height of the 

same part of the body-chamber over all, or measured on a tangent to 

the flank from the level of its umbilical border to the level of the 

, periphery, is about 71 mm. (66 on one flank, 76 on the other flank, 

in the specimen as preserved, the umbilical axis having an oblique 

position, due to crushing). The original breadth of the same part of 

the body chamber, allowing for crushing, was apparently not less

than 60 mm. ' 

Occurrence. Two imperfect specimens of this shell were collected 

by Doctor S tan ton in foothills near the railroad, at the northwest 

end of Malone Mountain, about 2 miles east-southeast from Finlay 

station, the horizon not more than 200 feet above the gypsum bed.

' AMMONOIDBA. 

Genus OPPELIA Waagen. 

OPPELIA ? FALLAX (C. and A.).

PI. XXII, figs. 2, 3.

Placenticeras fallax Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., No. 1, 

p. 17, PI. VIIT, figs. 1, 2.

This large, plain, compressed, and obtusely lenticular ammonite is 

rather common in the limestone portions of Theta subdivision of the 

Trio section, 1£ miles east of Malone station, but has been obtained 

thence in fragmentary specimens only.

The following is a translation of the original specific description:

Shell compressed, narrowly umbilicate. Spire composed of not very numerous 

embracing whorls, which almost completely hide the previous whorls. Flanks 

feebly convex, descending gradually toward the umbilical bordeu qnd with the 

same regularity toward the siphonal region, which is rounded and a little more 

narrow than the flanks; the greatest thickness of the shell is on the umbilical 

border. Umbilicus very narrow and deep, with vertical walls, with uncarinated border. Aperture very high, considerably invaded by the spire whorl, 

rounded in the upper part, of nearly elliptical form. Surface of the shell 

smooth on the last whorls, bearing in the earlier whorls fine lines of growth. 

Diameter, 104 mm.; breadth of the last whorl in relation to the diameter, 0.54; 

thickness of the last Avhorl in relation to the diameter, 0.32; diameter of the 

umbilicus in relation to the diameter. 0.16.
102 MALONE JUKASSIC FORMATION OF TEXAS. [BULL. 266.

To the above description Castillo and Aguilera add the following 

remarks:

We place this species in the genus Placenticeras, notwithstanding that by 

its form it could be considered as a Phylloccras, by the characters of the 

sutuval line which, though imperfectly visible in one of the specimens of our 

collection, does not present the saddles terminated by the roundels characteristic 

of the Phylloceras, only ramifications and subdivisions similar to.those of the 

Placenticeras.

As it makes some departures from the characters belonging to most 

of its congeners, this ammonite may seem at first sight almost as 

much of an anomaly in the genus Oppelia as it was supposed to be in 

Placenticeraft. But the suture, which has the lobes and saddles very 

few instead of many," and has the first lateral lobe contrastingly 

the largest, sufficiently distinguishes it from the latter genus and 

relates it to Oppelia and Haploceras, with which also agree its involute, narrowly umbilicated shell, its rounded venter, its rather compressed lenticular form,'and the absence of periodical constrictions. 

It seems indeed to have its closest affinities and to belong among,the 

round-ventered, phylogerontic forms of Oppelia which occur in the 

latest Jurassic rocks, in which this genus makes its final appearance; 

the venter, in 0. fallax, being rounded both on the outer and on the 

inner whorls.

The Malone Oppelia bears considerable resemblance to the Tithonian species, 0. waageni Zittel, having about the same outward form 

and being of large size; but it apparently lacks a vestige of even such 

feebly expressed, coarse lateral ribs, or undulations, as are seen on 

that shell, and is more critically distinguished from it by the characters of the suture. The first lateral saddle is much narrower in the 

Malone ammonite than in Oppelia waageni. and the first lateral 

lobe which is quite imsymmetrically branched in the latter shellpresents an almost symmetrical branching in O. fattax. In this lastmentioned character, 0. fallax departs from the condition most common in Oppelia and approaches the usual condition in Desmoceras, 

from which genus it is separated by the absence of constrictions. 

The siphonal lobe is about half as long as the first lateral lobe and 

ends in two small branches on either side.

Though commonly represented from the Malone district by whorl 

fragments of dimensions not or little exceeding those given by Castillo and Aguilera for the examples from the Sierra de Catorce, the 

shell attains a much larger size. One specimen, of which considerable portions were collected H miles east of Malone station, has in 

the largest preserved cross section of the body chamber, a height of 

about 145 and a breadth of at least 93 mm., while the diameter of

a My attebtion was first called to the few-lobed suture, as inconsistent with Placenticeras, 

hy Doctor Stanton. ,
CUAGIN.] DESCRIPTIONS OF SPECIES. 103

the coil (a large part of whose periphery is preserved) must have 

considerably exceeded a foot. The specific identification is tentative, 

as it is based on the comparison of imperfect specimens with Castillq 

and Aguilera's description and figures. The specimen figured is a 

young individual and the only one in the collection that shows more 

than a fragment of a complete volution.

Genus OLCOSTEPHANUS Neumayr.

OLCOSTEPHANUS MALONIANUS sp. n.

PI. XXIV, figs. .1, 2.

Shell large and moderately involute, consisting of massive whorls 

which are at least as high as or a little higher than wide, with flattish-convex flanks and broadly rounded periphery, about one-fourth 

of the height of each inner whorl embraced within the whorl next 

outer; umbilical costae not at all resembling compressed tubercles, 

but heavy, long, and truly rib-like, traversing the lower and middle 

parts of the flank- from the lower border to between half and twothirds 1'the height of the whorl, giving place at their upper.ends to 

numerous compressed, narrowly round-topped costellee which are 

fascicled mostly in threes at their origin, but are uniformly distributed upon the periphery of the whorls, over which they pass 

without interruption, swinging Very little forward; suture strongly 

dissected, the two lateral lobes and saddles large and complexly 

branching, the external one especially so. The body chamber is 

unknown.

Measurements. The largest known whorl section (which is in the 

septate portion of the shell) has the height and breadth about 110 and 

105 mm.; an inner one about 58 and 57 mm., respectively.

Occurrence. Only a few parts of whorls, most if not all of which 

belong to one specimen, were collected at the locality 1^ miles east of 

Malone station.

The species is intermediate in general proportions between the two 

species of Olcostephanus known from the Alamitos beds which 

seem to correspond in some measure with the Malone formation in 

Mexico: 0. " af. portlandicus de Loriol " and 0. potosina of Castillo 

a,nd Aguilera.

Genus PERISPHINCTES Waagen.

PERISPHINCTES CLARKI sp. n.

PI. XXIX, figs. 1, 2.

Shell large, discoidal, many whorled, broadly umbilicated; involution more than one-half; whorls ovate, the outer ones elevated or narrow-ovate in cross section, narrowed toward the venter, which is
104 MALCWE JURASSIC FORMATION OF TEXAS. [BULL. 26G.

rather narrowly rounded; the flanks flattish-convex; umbilical border 

rounded; the wall of the outer whorl sloping rather gently to the 

next whorl within it, that of the inner whorls descending somewhat 

more steeply below; inner whorls ornamented with strongly elevated, 

moderate^ close, but not crowded, dichotomous ribs whose branches 

separate at about the middle of the flank and continuously cross the 

venter, the lateral ribs not noticeably enlarged on the umbilical border, this ornamentation becoming gradually changed to large low 

undulations on the outer whorls and almost vanishing before the (presumably plain or nearly plain) body chamber is reached; septal line 

with two strong lateral lobes, which are rather strongly dissected, and 

a deep suspensive lobe; the first lateral lobe large, twice or more than 

twice as long as the second, longer than the siphonal lobe, and having 

three strong terminal branches of which the outer is subtended by a 

smaller branch; the second lateral lobe pinnate, not distinctly 

branched at summit; a noticeable lobe, similar to the second lateral 

lobe, but slenderer and about two-thirds as long, stands between the 

first lateral and the siphonal lobe; suspensive lobe consisting of one tall 

pinnate lobe, with strongly trifid summit, \vhich is outwardly preceded by a trio consisting of a small lobe flanked on either side by a 

lobule and is inwardly followed by two obtuse lobes the inner of which 

is very low and often 3-denticled. This description of the septal line 

relates to the later septa, the preceding ones being somewhat simpler.

Measurements. Height of largest cross section of whorl preserved 

in the type, 85 mm.; breadth of same, 54 mm.; span of umbilicus 

opposite same section, 90 mm.

Occurrence. The type represents a considerable and wholly septate 

part of the form and was obtained by Doctor Stanton from No. 13 of 

his Malone Mountain section on the west side of the mountain, about 

2 miles southwesterly from Malone station. He obtained a fragment

also on the east slope of the mountain near its southern end, .about 200 

or 300 feet above the heavy bed of gypsum which there forms the base 

of the mountain; and a poorly preserved specimen and fragment from 

foothills near the railroad, at the northwest end of Malone Mountain, 

a little over 2 miles east-southeast of Finlay station, not more than 

200 feet above the gypsum bed of that locality.

It is not unlikely that this is the same species as that figured arid 

briefly described from the Tithonian of Mexico as "Perisphinctes 

sp. (?)" by Castillo and Aguilera,0 and compared by them in its ribbing with P. lictor, P. haliarchus, and P. polygyratus. The septal 

line bears considerable resemblance to that of the latter species, which, 

from the White Jura Beta, Quenstedt 6 figures under the name of 

"Ammonites triplicatus allms."

 ' "Fauna Posil de la Sierra de Catorce, p. 35, PI. XIX. 

"Die Ammonitcn des Schwiibisclien Jura, pi. 100, fig. 8.
CRAGIN.] DESCRIPTIONS OF SPECIES. 105

'The species is named for Dr. Wm. Bullock Clark, professor of 

geology in Johns Hopkins University and director of the Maryland 

geological survey.

PERISPHINCTES AGUILERAI sp. n. 

PI. XXVIII, figs. 1, 2.

Shell large, discoidal; umbilicus large, spanning more than a third 

of the diameter of the shell, rather shallow, its wall descending almost 

vertically from a rounded border; whorls little involute, each concealing only between a fourth and a fifth of its predecessor, about 

three-fourths as broad as high, broadest in the lower third, their 

flanks flattened-convex, the venter rounded, apparently a little tectiforrn on the outer whorl; ornamented with very numerous compressed ribs, which arise independently at the umbilicus, have a 

somewhat backward inclination in ascending the umbilical wall, and 

cross the flanks with a gentle forward inclination and slight sigmoicl 

flexure, bifurcating at about the mid flank into parallel branches that 

sweep strongly forward on the ventral region so that those of opposite sides meet on the periphery at nearly a right angle; the ribs, and 

especially the ventral ones, close, yet narrower than the roundbottomed intervals between them, the ventral ribs of the inner whorls 

being very fine, those of the outer whorls large, though still compressed and strongly elevated; septal line strongly dissected, apparently not differing from that of Perisphinctes, though hitherto 

observed only .in part, the saddles at least not ending in roundels 

such as characterize the Phylloceratida?.

Measurements. Outer whorl attaining at least a height of 107 mm. 

and a breadth of 84 mm. The cross section of a smaller whorl has 

the same dimensions, 57 and 50 mm.

Occurrence. Seven fragments of this species werev obtained by 

.Doctor Stanton from the foothills west of Malone Mountain, about 

2 miles north of the southern end of the latter. The horizon is 

regarded by him as probably the same as one that yielded him specimens of the Exogyra, herein identified as E. potosina (narrow phase).

The species is named for Senor Jose G. Aguilera, director of the 

geological institute of Mexico.

PERISPHTNCTES POTOSINUS C. and A.

PI. XXIII, fig. 1.

PerispMnctes potosinus Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., 

No. 1, p. 31, PI. XVII, fig. 1 and PI. XXIV, fig. 2.

Among the specimens from the locality 1£ miles east of Malone 

station is a fragment of a Perisphinctes belonging to the series of
106 MALONE JURASSIC FORMATION OF TEXAS. [BOLL. 266.

P. contiguus Catullo, and that seems to agree sufficiently with the 

description and illustrations of P. potos-'ma C. and A. The lateral ribs, 

in form, size, interspacing, and manner of trifurcation, are those of 

F. contiguus, from which the Malone sheil differs in the more anteriorly inclined lateral ribs and in having the ventral ribs distinctly 

curved forward as they approach the periphery, on which they are 

slightly extinguished. The last-named feature, however, is not a 

specific difference; for while the ventral ribs in P. contiguus are 

usually uninterrupted, a slight peripheral attenuation of them- is 

noted by Toucas a as occurring in some varieties of this species in the 

Carpathians.

The fragment agrees in size with an intermediate part of the outer 

whorl of P. contiguus or P. potosinus, and the cross section of whorl 

which it indicates is about three-fourths as broad as high, measuring 

24 mm. in height and 18 or 19 mm. in breadth.

Siemiradzki & refers to P. potosinus as apparently identical with 

P. kokeni Behrendsen,e but there seem to me to be considerable differences between the two species. These differences, if we accept the 

description and the figure of the adult (PL XVII, fig. 1) and exclude 

the smaller and doubtfully pertinent figure (PI. XXIV, fig. 2) given 

by Castillo and Aguilera of their Perisphinctes potosinus, are as 

follows:

.P.IcoJceni. P.potosinus.

Involution $. Involution f to £.

Whorls broader (thicker) than high. AVhorls higher than broad.

Whorl cross section quadrilaterally Whorl cr'oss section flat-sided ovate.

rounded. Venter rounded.

Arenter flatly rounded. Lateral ribs bifurcate, the larger numLateral ribs bifurcate. ber becoming trifurcate on the last

Simple part of lateral ribs rather whorl.

slender. Simple part of lateral ribs rather stout.

PERISPHINCTES FELIXI C. and A. 

Pi. xxin, fig. 2.

Perisphinctes felixi Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., No. 

1, p. 25, PI. XVI, fig. 1.

A species of Perisphinctes apparently not distinct from P. felixi 

C. and A., but intermediate in some of its characters between the latter 

and the closely allied, if indeed really distinct P. lauri C. and A., 

is represented from the locality 1£ miles east of Malone station by a 

specimen showing part of three successive whorls.

The whorls are rounded in cross section, having their height and

« Bull. Soc. Geol. France, 3d ser., Vol. XVIII, p. 582.

6 Monogr. Bescbr. Perisphinctes, p. 170.

< Zeitschr. d. Deutsch. Geol. Gesellsch., Bd. 43, p. 406, pi. 24, figs. 1 and 2. 1891.
CRAGIN.] DESCBIPTIONS OF SPECIES. , 107

breadth about equal (25 mm.), yet having their greatest breadth in 

the lower part. The involution is between ^ and ^. The ribs are 

heavy and inclined forward; mostly bifurcate at about the middle 

of the flank,.but in one instance a rib is seemingly bidichotomous. 

the first bifurcation taking place on the umbilical border. The ventral ribs pass over the periphery without interruption, but are curved 

forward as they approach the median line so as to make a very obtuse 

angle, at which many of them suffer a very slight weakening. The 

specimen does not show the largest part of the last whorl, a fact 

to which the almost uniformly bifurcate character of the ribbing is 

probably due.

Doctor Stanton also has collected at this locality a small specimen 

that apparently represents the inner whorls of the same species. 

This has many of the ribs once bifurcate, the others simple.

The following is a translation of the original description of the

species':

Shell discoidal, spire composed of embracing whorls of nearly round cross 

section, visible in the umbilicus in a third of its width, having its major thickness near the umbilical border; flanks convex, descending gradually toward the 

umbilicus; siphonal region perfectly rounded. Umbilicus small, rather deep, its 

border not angulated. Surface covered with 46 to 48 strong, equal costellfe 

which bifurcate, some at the middle of the flanks and others a little earlier; 

of the former some trifurcate and the latter undergo a second bifurcation, 

which takes place at the same distance from the umbilicus as that of the other 

costelloe; three or four ribs remain simple; all cross the siphonal region forming a slight forward inflection. Aperture a little higher than wide, a little 

invaded by the whorl of the spire and rounded above. Three narrow constrictions [surcos] are seen, shallow and .parallel to the costellse. Diameter 60 mm., 

75 mm.'; breadth [height] of the last whorl with relation to the diameter 0.38, 

0.38; thickness of the last whorl with relation to the diameter 0.38, 0.38; diameter of the umbilicus with relation to the diameter 0.35, 0.33.

PERISPHINCTES SCHUCHERTI sp. n.

PI. XXV, fig. 1; PI. XXVI, tigs. 1-3; PI. XXVII, fig. 1.

Shell discoidal, moderately involute, each whorl embracing about 

a third of its predecessor; the umbilicus strongly excavated, its span 

equaling about a third of the corresponding diameter of tho shell; 

whorls laterally compressed, even the earlier ones being much higher 

than wide, the flanks flattened-convex, narrowed toward the siphonal 

side, which is rounded, umbilical border rounded above, descending 

almost sheerly below to the surface of the inner whorls; septal line 

with two lateral lobes, of which the first is large, ample-trunked and 

longer than the siphonal lobe, and ends in three branches, the second 

lateral lobe being well developed and considerably more than half as 

long as the first, suspensive lobe (nahtlobus} of intermediate steepness, presenting one conspicuously large auxiliary lobe; ribs gently
108 MALONE JURASSIC FORMATION OF TEXAS. [BOLL. 266.

inclined forward on the flanks, somewhat enlarged on the umbilical 

border, those of the earlier whorls very close and bifurcating or 

sometimes trifurcating at about the middle of the flank into feebly 

diverging smaller ones, an occasional rib remaining simple and then 

being usually accompanied by a short, independent rib, corresponding with one of those produced by bifurcation, this ornamentation 

becoming gradually obsolete on the greater part of the height of the 

flanks and also on a narrow median zone in the more mature portion 

of the shell, which portion is also usually encircled with large shallow constrictions at remote intervals; the ventral ribs about equal to 

the intervals between them.

Measurements. The maturer aspects of the shell are, represented 

only by fragments; the cross section of one of which has a height of 

47 mm. and a breadth of 27 mm. ,

Occurrence. The type material consists of several imperfect specimens and Various fragments, all collected by Doctor Stanton in 

foothills near the railroad, at the northwest end of Malone Mountain, 

about 2 miles east-southeast of Finlay station. Material obtained on 

the west side of Malone Mountain, from No. 13 of Malone Mountain 

section, includes a very doubtful fragment of this species from about 

2 miles west, of Malone station, and-a specimen, also doubtful, and a 

fragment from a point about three-fourths of a mile farther south. 

That collected I-}- miles east of Malone station includes a fragment 

which not improbably belongs to this species.

The septal line of P. schuclierti is of the same general pattern as 

that of P. inconditus Font., as figured by de Loriol," but differs from 

it by its broa'der first lateral lobe and in other details. Thev shell of 

P. scllucherti also differs from that of P. inconditus in that the latter 

has trifurcate and even sometimes quadrifurcate ribs, the ribbing on

the flanks of the inner whorls being very much closer in P. sclmclierti 

than in either inconditus or balderus.

The second specimen above mentioned is larger and less compressed 

than the others and has the ribs less inclined forward on the venter, 

and on part of the shell almost radially directed. I am uncertain 

whether it belongs to P. schucherti or is the young of a larger species. 

The ribs are, however, obsolete on the flanks, and the specimen is 

therefore referred here provisionally. It gives the following measurements: Greatest diameter, 125 mm.; span of umbilicus, 50 mm.; 

height of outer whorl in intermediate part, 45 mm.; breadth of same, 

30 mm. It is without constrictions, and in form and character of 

ventral ribbing bears a resemblance to Olcostephanus potosinus C. 

and A., a fossil from which in other respects it widely differs.

The species is named for Mr. Charles Schuchert, curator of invertebrate paleontology in the United States National Museum.

0 Foss. d. Baden, PI. XI, fig. Ic.
CRAGIN.] DESCRIPTIONS OF SPECIES. . 109

Genus ASPIDOCERAS Zittel. 

ASPIDOCERAS ALAMITOCENSIS C. and A.

PI. XXVII, fig. 2.

Aspidoccras alamitocensis Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., 

No. 1, p. 43, PL XXIII.

A portion of a shell which appears quite identical with this bulky 

ammonite was obtained 1-| miles east of Malone station. It includes 

about a fourth of a volution, belonging mostly to the septate part of 

the shell, but including also a small posterior fraction of the body 

chamber. The septal line is imperfectly shown, but the lateral lobes 

and saddles are large and coarsely dissected, the saddles having 

obtuse, the lobes having sharply pointed terminal divisions; and the 

auxiliaries (not visible in our specimen) are few, or at least not present beyond a narrow umbilical tract of the whorl. Of the two rows 

of tubercles, only one that which borders the umbilicus is shown, 

owing to the condition of the specimen. Traces of low ribs separated 

by broad and shallow valleys and crossing the broadly rounded outer 

side of the whorl, are distinguishable. 'The specimen indicates a 

shell at least as large as the largest of the Alamitos specimens whose 

dimensions are given by Castillo and Aguilera. In the matrix with 

it are several imperfect specimens of Exogyra subplicifera.

As compared with the rich invertebrate fauna, the known vertebrate fauna of the Malone formation is pitifully meager.

Besides a few ill-preserved and problematical structures which may 

pertain to Vertebrata, the Malone Hills, 1£ miles east of Malone station, have yielded two cycloid fish scales, between circular and quadrate in outline and a little smaller in area than a 1-cent piece; one 

well-preserved hemispherical tooth, about the size of a checkerberry, 

of a Pycnodont; and a number of fragments of bones of rather large 

swimming reptiles, which are probably in part those of Enaliosaurs.

The east slope of Malone Mountain, a mile north of its southern 

end, has yielded Doctor Stanton a shark's spine of indeterminate 

genus.

While the Upper Jurassic rocks of Potosi, Oaxaca, etc., Mexico, 

have yielded a considerable number of invertebrates some now 

known, others not yet known, from Texas they have apparently 

yielded no vertebrate remains of record whatsoever; and the above 

brief . notices therefore apparently embrace all that is known of the 

Vertebrata of the Upper Jurassic in Texas and Mexico.

PLATES.

111

PLATE II.

Bull. 266 05 M 8 113
PLATE II.

FIGS. 1-3. ASTBOCCENIA MALONIANA Vaughan, sp. n. (p. 34.).

Figs. 2, 3. Coralla of natural size showing variation in mode of growth.

Fig. 3. Several corallites from fig. 2, enlarged 6 diameters. 

FIG. 4. SEKPULA sp. (p. 37).

Cross sections of tubes. ; 

FIGS. 5, 6. SERPULA GORDIALIS Schlotheirn (p. 37).

Several specimens growing on Astrocoania maloniana. 

FIG. 7. BERENICEA MALONIANA sp. n. (p. 38).

Enlarged 3 diameters.

114
U. S, GEOLOGICAL SURVEY BULLETIN NO. 266 PL. II

MALONE JURASSIC INVERTEBRATES.
PLATE III.

115
PLATE III.

FIGS. 1-6. GKTPH^E MEXICANA Felix (p. 39).

Fig. 1. Young specimen, natural size.

Fig. 2. Young striated individual, enlarged 1£ diameters.

Figs. 4-6. Mature specimen. 

FIG. 7. EXOGYRA'POTOSiNA Castillo and Aguilera (p. 41).

See PI. IV for additional figure. 

FIGS. 8, 9., PLICATULA SPOBTELLA sp. n. (p. 43).

Two views of the imperfect type specimen.

116
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. Ill

MALONE JURASSIC INVERTEBRATES.
PLATE IV.

117
PLATE IY.

FIGS. 1-4. EXOGYBA SUBPLICIFERA Felix (p. 41.). 

FIGS. 5. 6. LIMA INTEBLINEATA sp. n. (p. 43).

Fig. 5. Type specimen, natural size.

Fig. 6. Part of sculpture, enlarged 3 diameters. 

FIG. 7. EXOGYKA POTOSINA CastUlo and Aguilera (p. 41).

See PI. Ill, fig. 7. 

ITiGS. 8, 9,10. GERVILLIA CORRTJGATA sp. n. (p. 46).

Fig. 8. Right valve with most of the shell exfoliated.

Fig. 9. Left valve of another specimen in. same state of preservation.

Fig. 10. Small distorted left valve showing strong sculpture of umbo. 

FIGS. 11, 12. PECTEN INSUTUS sp. n. (p. 44).

118
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. IV

10

MALONE JURASSIC INVERTEBRATES.
PLATE V.

119
PLATE V.

FIG. 1. GERVILUA CINDERELLA sp. n. (p. 47)..

FIGS. 2, 3. GERVILLIA ? RIOGRANDENSIS sp. n. (p. 47).

Side and profile views of the type specimen. 

FIG. 4. LIMA (CTENOSTREON) BIOGRANDENSIS sp. n. (p. 44).

120
BULLETIN NO. 266 PL. V

MALONE JURASSIC INVERTEBRATES.
PLATE VI.

121
PLATE VI.

FIGS. 1, 2. MODIOLA MALONIANA sp. n. (p. 48).

Side and profile views of the type specimen. 

FIG. 3. MODIOLA GENICULATA sp. n. (p. 49). 

.FIGS. 4, 5. MYTILUS NUNTIUS sp. n. (p. 48).

Side and profile views of the type specimen. 

FIG. 6. AKCA DUMBLI sp. n. (p. 51). 

FIGS. 7, 8. AKCA TAFFII sp. n. (p 50).

Side and profile views of the type specimen.

FlGS. 9, 10. CUCULLuEA ? TEXICOSTATA Sp. n. (p 52).

Fig. 9. The imperfect type specimen.

Fig. 10. Portion of surface enlarged. 

FIGS. 11,12. CUCULI^EA CASTILLOI sp. n. (p 54).

Side and profile views of the type specimen. 

FIG. 13. LEDA ? NAVICULA sp. n. (p. 55).

122
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. VI

13

11

MALONE JURASSIC INVERTEBRATES.
PLATE VII.

123
PLATE VII.

FIGS. 1-8. PINNA QUADBIFONS sp. n. (p. 49). 

124
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. VII

MALONE JURASSIC INVERTEBRATES.
PLATE VIII.

125
PLATE VIII.

FIGS. 1, 2. TBIGONIA VYS.CHETZKII Cragin (p. 56).

See PI. IX, fig. 3, for anterior view of specimen represented by fig. 1.

126
0. 6. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. VIII

MALONE JURASSIC INVERTEBRATES.
PLATE IX.

127
PLATE IX.

FIGS. 1-3. TRIGONIA VYSCHETZKII Cragin (p. 5G). 

See PI. VIII, fig. 1, for side view of fig. 3. 

FIGS. 4-5. TRIGONIA CALDERONI (Castillo and Aguilera) (p. 59).

128
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. IX

MALONE JURASSIC INVERTEBRATES.
PLATE ./V.

Bull. 26G 05 M Q 129
PLATE X.

FIGS. .1, 2. TKIGONIA GOODELI.II Cragin (p. 58). 

FIGS. 3-G. TRIGONIA I-ROSCABRA t$p. n. (p. GO). 

FIG. 7. TKIGONIA PK/ESTRIATA sp. n. (p. 61). 

FIGS. 8-11. TRIGONIA MUNITA sp. n. (p. 62).

130
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. X

10

MALONE JURASSIC INVERTEBRATES.
PLATE XI.

131
PLATE XI.

FIGS. 1, 2. TRIGONIA RUHICOSTATA sp. n. (p. 03).

Side and profile views of the type specimen. 

FIG. 3. TRIGONIA CONFERTICOSTATA sp. n. (p. 63).

FlG. 4. ASTABTE BKEVIACOLA Sp. U. (p. 64). 

FIGS. 5, 6. ASTARTE POSTICALVA Sp. n. (p. 07).

Fig. 5. Left valve of type enlarged 2 diameters. 

Fig. 6. Dorsal view of another specimen.

FlG. 7. ASTAKJE CISATICULA Sp. 11. (p. 68).

FlGS. 8. 9. ASTAKTE? ISOUONTOIDES Sp. 11. (p. 67).

FIGS. 10, 31. ASTAKTE MALONENSIS Cragin (p. 65). 

See PI. XII for additional figures.

132
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XI

11

MALONE JURASSIC INVERTEBRATES.
PLATE XII.

133
PLATE XII.

FIGS. 1-3. ASTARTE MALONENSIS Cragin (p. 05). 

See PI. XI for additional' figures.

FlGS. 4-6. PTYCHOMYA STANTONT Sp. 11. (p. 69).

Fig. 4. Natural size.

Figs. 5, 6. Another specimen enlarged 1* diameters. 

FIGS. 7, 8. UNTCARDIUM ? TRANSVERSUM sp. n. (p. 70). 

FIGS. 9-11. UNICARDIUM ? SEMIROTUNDUM sp. n. (p. 70).

134
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XII

MALONE JURASSIC INVERTEBRATES,
PLATE XIII.

135
PLATE XIII.

FIGS. 1, 2. CYPRINA STREERUVITZII Cragin (p 78).

FlG. 3. LUCINA I'LANIUSCULA Sp. 11. (p. 75).

FIGS. 4, 5. LUCINA POTOSINA Castillo and Aguilera (p. 72). 

FIGS. 0-1.0. LUCINA POTOSINA v:ir. nietrica var. n. (p. To). 

FIGS. 11, 12. CYPRINA COTEROI Castillo and Aguilera (p. 77). 

FIG. 13. TAPES CUNEOVATUS sp. 11. (p. 79).

136
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XIII

13

11

MALONE JURASSIC INVERTEBRATES.
PLATE XIV.
PLATE XIV.

FIGS. 1, 2. CYPRINA STREEKUVJTZU Oagin (p. 78).

Two views of type specimen in collection ot! Geological. Survey of Texas. 

See PI. XV, fig. 1, for additional figures of same specimen.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XIV

f

MALONE JURASSIC INVERTEBRATES.
PLATE XV.

139
PLATE XV.

Fie. 1. CYPRINA ? STKEEuuviTzrr Oagin (p. 78).

See PI. XIV for other views'of same specimen. 

FIGS. 2, ?.. PHOLADOMYA TOSTA sp. n. (p. 79).

Opposite views of the same specimen.

140
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XV

MALONE JURASSIC INVERTEBRATES.
PLATE XVI.
PLATE XVI.

FIGS. 1, 2. PHOLADOMYA MARCOU'I sp. n. (p. SO).

Side and anterior views of the saaie specimen. 

FIGS. 3, 4. PHOI.AIJOMYA I-R.^EPOSITA sp. n. (p..82).

Two views of the same specimen. 

FIGS. 5. 6. PHOLADOMYA FAUCICOSTA Koenier? (p. 81).

Side and dorsal views oL" the same specimen, 

FIGS. 7, S. ANATINA OBLIQUIPLTCATA sp. n. (p. 85). 

FIGS. 0, 10. ANATINA V J.'UCUUJJ'.EBA sp. n. (p. 86).

. .14-'
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XVI

MALONE JURASSIC INVERTEBRATES.
PLATE XVII.

J43
PLATE XVII.

Frcs. 1-5. PLEUUOMYA INCONSTANS Castillo and Aguilera (p. 82). 

See PI. XVIII for aaditional figures,

144
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XVII

MALONE JURASSIC INVERTEBRATES.
PLATE XVIII.

Bull. 200 05 M 10 145
PLATE XVIII.

FIGS. 1-3. PLF.UROMYA INCONSTANS Castillo and Aguilera (p. 82).

See PI. XVII for additional figures. 

FIG. 4. PLEUROMYA INCONSTANS var. curta var. u. (p. 84).

See PI. XIX for additional figures.

14G
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XVIK

MALONE JURASSIC INVERTEBRATES.
PLATE XIX.

147
PLATE XIX.

FIGS. 1, 2. PLEUBOMYA INCONSTANS var. curta var. n. (p. 84).

See PI. XVIII for additional figure. 

FIGS. 3-5. MARTESIA MALONIANA sp. n. (p. 87).

Figs. 3, 4. Side and dorsal views of the same specimen.

Fig. 5. Anterior view of another specimen. 

FIG. 6. THRACIA 'i MALONIANA sp. u. (p. 86).

FlG. 7. CORBI'LA MALONIANA Sp. 11. (p. 87).

FlGS. 8. 9. P LEU KOTO MART A CIRCUMTRUJNOA SJ). 11. (p. 88).

Two views of the same specimen. 

FJGS. 10, 11. TURBO BENEOLATI-IRATA sp. n. (p. 88).

Two views of the type. 

FIGS. 12-M. DELPHINU.LA STANTOWI sp. n. (p. 89).

Fig. 12. Dorsal view slightly restored.

Fig. 13. Enlargement of part of surface sculpture of same specimen.

Fig. 14. Aperture view of a small weathered specimen. 

FIG. 15. NKRLTA FINLAYENSLS sp. u. (p. 90). 

FIGS. 10, 17. NERITA PEROBLATA sp. u. (p. 91).

Two views of the type.

148
BULLETIN NO. 266 PL. XIX

t

12 13

10

14

' , «* 

17

MALONE JURASSIC INVERTEBRATES.
PLATE

149
PLATE XX. '

FIGS. 1-4. NERITA NODILIKATA sp. n. (p. 00).

Fig. 1. Apical view of a medium specimen.

Fig. 2. Aperture view of another specimen viewed obliquely from the base

so that the spire is concealed. 

Fig. 3. Dorsal view of a young individual. 

Fig. 4. Apical view of an internal cast.

FlG. 5. TURRITELLA BURKARTI Sp. 1).' (p. 92).

FIG. (>. VFRMETUS CORNEJOI Castillo and Aguilera (p. 92).

Fics. 7. 8. NATICA WILLIAMSI sp. n. (p. 03).

FIGS. '.'). 10. NATICA BILABIATA sp. n. (p. 05).

FIGS. 11, 12. NATICA INFLECT A sp. n. (p. 04).

FIG. 18. CEIUTHIUM ARCUIFERUM sp. n. (p. 90).

FIG. 14. ACT^EONINA ? MAT.ONIANA sp. n. (p. 00).

FIGS. 15, 10. NATFCA FINLAYENSLS sp. n. (p. 94).

150
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XX

11

13

14

MALONE JURASSIC INVERTEBRATES.
PLATE XXI.

151
PLATE XXL

FIGS. 1-3. NERINEA GOODELLH sp. n. (p. 90). 

FIGS. 4, 5. NERINEA CIRCUMVOLUTA sp. n. (p. 97).

Fig. 4. Longitudinal section enlarged 2 diameters. 

FIGS. 0-9. NKUINELLA STANTONI sp. n. (p. 98).

Fig. 8. Fragment enlarged 3 diameters.

Fig. 9. Longitudinal, section of same fragment enlarged.

FlG. 10. PSKUDOMELANIA GOODELL11 Sp. 11. (p. 95).

152
U. S. GEOLOGICAL SURVEV BULLETIN NO. 266 PL. XXI

MALONE JURASSIC INVERTEBRATES.
PLATE XXII.

153
PLATE XXII.

Fia. 1. NAUTILUS BUBKARTI Castillo and Aguilera (p. 100). 

Ftos. 2, 3. OPPELIA ? FALLAX Castillo and Aguilera (p. 101).

154
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XXII

MALONE JURASSIC INVERTEBRATES,
PLATE XXIII.

155
PLATE XXIII.

FIG. 1. PFRISPFITNCTES POTOS.INUS Castillo and Aguilera (p. 105). 

Fro. 2. PER.ISPHINCTES FELIXI Cnstillo and Aguilera (p. 106). 

FIG. 3. NAUTILUS NAUFRAGUS sp. n. (p. 100). 

See PI. XXIV, flg. 3.

156
BULLETIN NO. 266 PL. XXIII

MALONE JURASSIC INVERTEBRATES.
PLATE XXIV.

157
PLATE XXIV.'

FIGS. 1, 2. OLCOSTEPHANUS MALONIANUS sp. n. (p. 103).

Lateral and ventral views of two fragments. 

FIG. 3. NAUTILUS NAUFHAGUS sp. n. (p. 100).

'Ventral view of specimen represented by PI. XXI11, fig. 3.

15S
U. 3. GEOLOGICAL SURVEY BULLETIN NO, 266 PL. XXIV

MALONE JURASSIC INVERTEBRATES.
PLATE XXV.

159
PLATE XXV.

FIG. L PEKISPHTNCTES SCIIUCHKRTI sp. n. (p. 107).

See Pis. XXVI and XXV11 for additional figures.

160
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XXV

MALONE JURASSIC INVERTEBRATES.
PLATE XXVI.

Bull. 260 05 M 11 161
PLATE XXVI. ^

FIGS. 1-3. PERISPHINCTES SCHUCHERTI sp. n. (p. 107).

Fig. 1. Ventral view of specimen figured on PL XXV. 

Fig. 2. Side view, of smaller specimen.

Fig. 3. Part of suture showing first and second lateral lobes from another 

specimen enlarged 3 diameters.

See PL XXVII for additional figure.

163
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XXVI

MALONE JURASSIC INVERTEBRATES.
, PLATE XXVII.

163
PLATE XXVII.

FIG. 1. PERISPHINCTES SCHUCHERTI sp. n. (p. 107).

See Pis. XXV and XXVI for additional figures. 

FIG. 2. ASPIDOCERAS ALAMITOOENSIS Castillo and Aguilera (p 109).

Ventral view of a fragment.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. xxv

MALONE JURASSIC INVERTEBRATES.
PLATE XXVIII.

165
PLATE XXVIII.

FIGS. 1, 2. PEBISPHINCTES AGUILEBAI sp. n. (p. 105). 

166
U. S. GEOLOGICAL SURVEY

,4

MALONE JURASSIC INVERTEBRATES.
PLATE XXIX.

167
PLATE XXIX.

FIGS. 1, 2. PERISPHINCTES CLAEKI sp. n. (p. 103). 

Fig. 1. A large imperfect specimen. 

Fig. 2. Septum of same, somewhat weathered.

168
U. S. GEOLOGICAL SURVEY BULLETIN NO. 266 PL. XXIX

\

\

MALONE JURASSIC INVERTEBRATES.
INDEX.

[Names in italic are synonyms; figures in black-face type denote pages on which species are described; 

figures in italic refer to illustrations.]

A.

Page.

Actaeonella... ............................. 93

dolium ................................. 30

Actaeonidffi ................................ 99-100

Actseonina ................................ 99-100

maloniana sp. n ..:........... 17, 91MOO, 150

Aguilera, J. G., on Mexican geology.S..... 21

See also Castillo and Aguilera. 

Alamitos beds, correlation of............... 20

Amauropsis ................................ 93

Aminonoidea............................. 101-109

Anatina.................................... 85-86

obliquiplicata sp. n ............ 17,85-86, U2

? pliculifera sp. n.................. 17,8«, 142

tosta .................................... 10,19

Anatinidoe.................................. 85-86

Annelida......................I............ 37

Anthozoa................................... 34-35

Area........................................ 50-52

?dumblisp. n ................. 16, 51-52, m

tafflisp. n...................... 17, 50-51, 122

Arcidse..................................... 50-55

Aspidoceras ................................ 109

alamitocensis.................... 17, 109, 161,.

Astarte ..................................... 64-68

breviacola sp. n............. 21,64-65, 78, m

craticnla sp. n..................... 17,68, iS2

excavata ............................... 66

? isodontoides sp. n............. 17,67-68, 132

malonensis ............................ 17,18,

19,40,43,44,49,53,66-66, 83, 192, m 

microphyes........................ 17,21,43,64

neocomiensis........................... 66

posticalva sp. n.................... 17,67, 132

Astartidse................................... 64-68

Astrocoenia................................. 34-35

maloniana sp. n ............... 16,34-86, lilt

Aviculidse.................................. 46-48

B.

Berenicea ....... 1.......................... 38

maloniana sp. n.................... 16,88, 1U

microstoma ..................... ...... 38

teuera.................................. 38

Bluff bed, location of....................... 28

See also Orbitolina limestone. 

Bluff Mesa, rocks of ........................ 32

Bohm, G., on Ccelastarte ................... 66

Bryozoa ........\........................... 38

C.

Cajoncito Canyon, rocks in 

Calloarca...................

Caprina occidentalis .......

sp.

Page. 

33 

51

30

31

Castillo and Aguilera on Mexican fossils. 21,42,

53,72,73,83-85,92,100-104,106-107,10!)

Catorce, Sierra de, Mexico, fossils from .... 21

Cephalopoda............................. 100-109

Cerithiidse.................................. 99

Cerithium.................................. 99

arcuiferum sp. n................ v . 17,99, 150

Chemnitzia goodellii....................... 17,18

Clark, W.B., acknowledgments to ......... 22

Clavellatee............................... 56,57,61

Ccelastarte.................................. 66

Coalenterata................................ 34-35

Corbula .................................... 87

? maloniana sp. n.................. 19,87, U8

Costatae.................................. 20,63-64

Crassatella cornueliana .................... 71

Crassatellidse............................... 69-71

Ctenostreon proboscidea ................... 44

Cucullsea.................................... 52-55

castilloisp. n .................. 18,54-55, 122

catorcensis......................... 17,53-54

( Trigonarca) catorcensis ................ 53

gratioti................................. 53

terminalis.............................. 63

? texticostata sp.n................. 17,52, 12%

transpecosensis.................. 10,17,52-53

Cummins, W. F., work of.................. 11,32

Cycloid fish scales......................... 17,109

Cyprimeriafmexicana...................... 74-75

Cyprina .................................... 77-79

coteroi.......................... 17,72,77, 136

roemeri................................. 78

streeruvitzii ......... 10,17,78-79, 1S6,138, UO

texana...........i...................... 78

(Roudairia) streeruvitzii................ 78

(Venilia) ceteroi......................... 77

Cyprinidse.................................. 77-79

D. 

Delphinula................................. 89-90

stantonisp. n ............... 17,88,89-00,7-45

Diastoporidse............................... 38

Bumble, E. T., fossils lent by ........ ...... 12

Eagle Mountains, location and character of. 32

169
170

Page. 

Echinodermata............................. 35-36

Enaliosaur remains ....................... 17,109

Enallaster texanus......................... 31

Epiaster whitei............................. 31

Etholen beds, correlation of................ 10,28

occurrence of........................... 10

Exogyra.............................. 26,39,41-43

arietina ................................ 81

auricularis............................. 41

drakei var.............................. 31

plicifera................................ 41

potosina.. 19,41-43,47-48,80,85,87,105, 116,118 

quitmanensis........................... 29

1 subplicifera........ 16,17,21,40,41,49,109, 118

texana ................................. 30

Felix, J., fossils collected by ............... 41

on Mexican fossils.... 21,37,41,45-46,57-58,64 

Finlay, fossils from near.................... 13,18

location of.............................. 9

Finlay Mountains, location and character

of............................... 32

Fishes, cycloid, scales of.................. 17,109

Forbes, E., on Ptychomya.................. 71

Fossils, distribution of ..................... 16-19

local derivation of..................... 13

Fossils, invertebrate, descriptions of...... 34-109

plates showing....................... 111-168

Fossils, vertebrate, mention of............. 109

Fredericksburg group, occurrenceand character of...................... 28,30-32

G.

Gannett, Henry, on Texas altitudes........ /9

Gastropoda ................................ 88-100

Gervillia.................................... 46-48

Cinderella sp. n................. 19,47, 85, 120

corrugata sp. n........ 16,46-47, 48,88-89, 118

riograndensis sp. n............. 19,47-48, 1%0

Gilcrease, J. N., acknowledgments to...... 22

Glen Hose beds, correlation of.............. 10

fossils of................................ 10

Goldfuss, A., on Exogyra................... 42

fossil identified by...................... 92

Goniomya calderoni......................... 59

Goodell, E. R.,fossils collected by.... 11,22,59,64

work of................................. 11,22

Goodell, R. W., fossils collected by. 9,11,22,59,64 

on MaloneHills........................ 15

Gresslya gregaria........................... 85

Gryphsea calceola var. nebrascensis....... 40

corrugata............................... 31

mexicana Felix........................ 16-19,

21,25,26,36, 39-40,42,47,49,89, 116 

mueronata? ............................. 27'

washitaensis............................ 31

Gypsum, occurrence of............... 15-16,26-27

H. 

Hamites fremonti .......................... 31

Haploceras................................. 102

mazapilensis........................... 21

Holectypoida............................... 35-36

Holectypus................................. 35

? sp ..................................... 17,36

Hyatt, Alpheeus, on Ctenostreon ........... 44

I. r*age.

Inoceramns labiatus........................ 30

Invertebrates, plates showing............ 111-168

Iota member, fossils of..................... 14

occurrence and character of............ 14,16

K.

Kappa member, fossils of................... 14

occurrence and character of............ 14-16

L. 

Leda.:...................................... 55

? navicula up. n .................... 17,65, l%2

Lenk, H., on Mexican fossils............... 44

Lima .............................:.:.-..... 43-44

comatulicosta .......................... 45-46

crenulicosta............................ 43

interlineata sp. n............ 18,43-44,78, 118

(Radula) interlineata.................'.. 16

(Ctenostreon) riograndensis sp. n .. 16,44, ISO 

wacoensis .............................. 13,43

Limidse..................................... 43-44

Lissochilus ................................. 90

Literature of Malone beds.................. 10-13

Lucina ..................................... 72-75

coetoi................................... 75

emarginata sp. n ...................... 74-76

metrica. ............................... 42-43,73

? mexicana............................. 17

planiuscula sp. n................... 18, 75, 1S6

potosina........................ 17,72-73, 1S6

var. metrica........ 17-19,42^3, 73-74, 136

Lucinidse................................... 72-77

Lycett, J., on Ptychomya .................. 71

onTrigonia ............:............... 57,60

M.

Malone, fossils from near .................. 13

location and elevation of.............. 9,24

Malone district, geology of.'................ 13-16

location of.............................. 9

stratigraphy of......................... 23-33

study of, history of..................... 10-13

topography of.......................... 24

Malone fauna, age and correlation of. 10-12,19-21 

Malone Hills, fossils from.................. 16-17

location of.............................. 13

Malone Mountain, fossils from............. 17-19

location and elevation of.............. 9,24

rocks of ................................ 24

section of............................... 25-27

stratigraphy of......................... 23-33

Map of Sierra Blanca region ............... 22

Martesia.................................... 87-88

maloniana sp. n ............. 17,18,87-88, U8

Mexico, Jurassic fossils from............... 20,21

Alamitos formation in, correlation of

Malone formation with ........ 20,21

Modiola .................................... 48-49

geniculata sp. n............'........ 18, 49, in

maloniana sp. n.......... 16,18,40,48-49. i22

Moesch, C., on Pholadomya................. 81

Mollusca .................................. 39-109

Molluscoidea............................... 38

Mountain bed, age of ..........--.-.-.----- 32

occurrence and characte- of........... 29
INDEX. 171

Page. 

Mule Canyon, fossils from.................. 11

Myid£e. ..................................... 87

My tilidae ................................... 48

Mytilus..................................... 48

afer.. .................................. 48

decussatus .............................. 48

eduliformis. . ...............:........... 48

nuntius sp. n. ...........:.......... 48, 78, HZ

sublcevis ................................ 48

N.

Natica.......................... ............. 93-95

arguta .................................. 94

bilabiata sp. n ...................... 17, 95, 150

finlayensis sp. n ................ 18, 94-86, 150

in flecta sp. n ................. 17, 18, 93, 94, 150

pedernalis. . ............................ 29

prsegrandis*. ............................ 29

williamsi sp. n ............ 17, 88, 90, 93, 94, 150

Naticidse ................................... 93-95

Nautiloidea .............................. 100-101

Nautilus. ................................. 100-101

burkarti .......................... 18, 100, 151,

naufragus sp. n. .......... 18, 100-101 , 151,, 156

Neithea texana............................ .. 31

Neocene rocks, erosion of .................. 13-14

occurrence of........................... '13-14

Nerinea .................................... 96-98

circumvoluta sp. n ............. 17,97-98, 152

goodellii ap. n......... 17,19,38,96-97,98,752

goodhallii .............................. 97

Nerineidse .................................. 96-98

Neri nella ................................... 98

stantoni sp.n ................... 17,18,98,^52

Neri ta ...................................... 90-91

chromatica .............'................ 91

finlayensis sp. n. ................ 18, 90-91, ll£

nodiliriata sp. n ........ 17, 88, 90, 91, 93, 99, 150

neumayri. . ............................. 91

peroblata sp. n ..................... 17, 91, 11,8

zitteli. .................................. 91

Neritidae. .................................... 90-91

Neumayrand Uhlig, onNeocomian fossils.. 20 

Nodosaria texana .......................... 27, 31

Nuculidffi. . ................................. 55

0. 

Olcostephanus. ............................. 103

malonianus sp. n .................. 17, 103, 158

portlandicus. . .......................... 103

potosina .............................. 103, 108'

Oppelia. .................................. 101-103

? fallax .................... 17, 19, 101-102, 151,

waageni ................................ 102

Orbitolina limestone, occurrence and character of ................... 28-29, 32-33

Orbitolina texana ....................... 28, 29, 31_

Ostrea ................................ 29, 31, 39-40"

sp . ..................................... 16, 39

....... .........^.. .............. 39-43

P. 

Pandora ? eequi valvis. ...................... 71

Pecten ................ 1 ..................... 26, 44

insutus...... .................. 16,18,19,42, US

(Camptonectes) insutus ............... 44-46

Page. 

Pectinidse .................................. 44-46

Pelecypoda................................. 39-88

Perisphinctes.................... 20,21,26,103-108

aguilerai sp. n.................... 19,105, 166

bal derus............................... 21,108

clarkisp.n................ 18,19,103-105,166

contiguus............................... 106

felixi......................... 17,106-107, 156

haliarchus.............................. 104

inconditus.............................. 108

kokeni ............................... 105,106

lictor................................... 104

mazapilensis........................... 21

polygyratus ............................ 104

potosinus.................... 17, 105-106, 156

schucbertisp.n... 17,18,107-108,160, 162,161, 

Pholadidse ................................. 87-88

Pholadomya................................ 79-82

Candida................................ 80

dumbli................................. 30

glabra.................................. 80

marcoui sp. n................ 17,19,80-81, U2

paucicosta?..................... 17,18,81, J42

prajposi tasp. n..................... 17,8'2, 11,2

ragsdalei. ................................ 70

tostasp.n ...................... 17,79-80, 11,0

Pholadomyidse..........1................... 79-85

Phylloceras................................. 102

Pinna ....................................... 49-50

quadrifrons sp. n. 16,18,19,26,36,42, 49-50, 742 

Pinnidse..........'.......................... 49-50

Placenticeras............................. 101,102

fattax................................... 101

Pleuromya ................................. 82-85

inconstans.........'.............. 11,17-19,25,

26,36,40,42,48-49, 72, 82-84, 744, U6 

var. curta var. n ..... 17,19,84-85, J46, 11,8

peregrina............................... 84

Pleurotomaria.............................. 88

circumtrunca sp. n ....... 17,48,88,89,99, 1!£

Pleurotomariidse........................... 88

Plica tula................................... 43

incongrua.............................. 31

sportellasp.n...................... 16,43, 776

Porites astreoides........................... 34

Pseudomelania............................. 95-96

goodelliisp.n ..................... 95-96,152

Pseudo-Quad raise .......................... 57

Ptychomya.............................. 16,69-71

agassizii ................................ 71

buchiana............................... 70

complicata ..................... .. :>..... 69-70

dcedalea................................ 70

germani................................. 70

koeneni................................ 69-70

neocomiensis.........................'.. 70

ragsdalei ............................... 70

robinaldina ............................ . 70

solita................................... 70

stantoni sp. n................... 17,69-71,734

zitteli................................... 19,70

sp ...................................... 70

Pycnodont tooth .......................... 17,109

Pygurus .................................... 36

sp ...................................... 18,36

Pyramidellidte ............................. 96-96
172 INDEX.

Page.

Q.

Quadratse................................... 57,61

Quenstedt, F. A., on Perisphinctes......... 104

Quitman Arroyo, section near.............. 30-32

Quitman bed, occurrence and character of. 28-29

Quitman Canyon, section in................ . 28

Quitman Mountains, location of ........... 9,28

section of............................... 30

R.

Radula..................................... 43

Red-Bull Canyon, fossils from.............. 11

Remondia.................................. 29

Reptiles, remains of, in Malone formation. 17,109 

Requienia.................................. 29

Reuss, A. E., on Berenicea................. 38

S.

Scabrse .................................. 56,60-62

Schlcenbachia acutocarinata............... 31

inflata.................................. 72

serratescens .....r...................... 31

vespertina .............................. 30,31

Schlosser, Max, on Nerita.................. 91

Schuchert, Charles, acknowledgments to.. 22 

Section, geologic, of Malone Mountain..... 25-27

Selachian remains.......................... 17

Serpula..................................... 37

gordialis .................. 16,17, »7,40,78, m

sp ....^............................. 16,37,.m

Siemiradzki, Joseph, on Perisphinctes.... 20,106

Sierra Blanca region, geology of..... 23-24,28-29

location and character of.............. 32

mapof.................................. 22

South America, fossils from, comparison of '

Malone species and ............ 21

Sowerby, J. de C., on Nerinea.............. 97

Spatangorda................................ 36

Spondylidse ................................ 43

Stanton, T. W., fossils collected by........... 35,

36,41,43,47,49,50,55,59-61,76,81,

87, 92, 94-96, 98-100, 105, 107, 109

letter of transmittal by................. 7

on stratigraphy of Malone Mountain

and vicinity.................... 23-33

work of......................... 9-12,17-19,22

Steinmann, G., on Nigonia.............. 57,70-71

on Ptychomya.......................... 20

Stoliczka, F., on Astarte.................... 66-67

on Ptychomya.......................... 71

T. 

Taff, J. A., on Malone district..... 15,24,27,30,32

work of................................. 9-11

Tapes....................................... 79

? cuneovatus sp. n ................. 17,79, 136

Terebratula (Kingena) wacoensis..*........ 31

Theta member, fossils of............. 14,16-17,21

occurrence and character of........ 13-14,16

Thracia..................................... 86

incerta ................................. 86

? maloniana sp. n.................. 17,86, U8

Titania, Cerro de, fossils from.............. 21

Page. 

Trigonia.............................. 20,26,56-64

calderoni.............. 17,18,43,60-60,96, 128

conferticostata sp. n............ 17,63-64, 132

goodellii..................... 17,19,58-59, ISO

herzogi.................................. 57

munita sp. n.............. 17-19,62-63,96, ISO

prsestriata sp. n.............. 18-20,61-62, ISO

proscabra sp. n ........ 17,18,20,60-61,78, ISO

rudicostata sp. n ................ 17,63,64,732

sologureni................... ^........ 24,56,58

stolleyi ?................................ 29

sulcataria .............................. 60

taffli.............................. 10-11,29,97

transitoria..................... 20,22,57-58,70

vyschetzkii..................... 10-11,17, 20-

22, 44, 48, 56-58, 78, 82-83, 126,128 

sp ...................................... li

Trigoniidee................................. 56-64

Trinity group, occurrence and character

of............................ 28,31,32

Trio, the, fossils from near................. 17

location and subdivisions of............ 13

Trochidse................................... 88-90

Truncate Mound, location of and fossils

from............................ ] 3-14

Tryon, G. W., on Calloarca................. 51

on Mytilus ............................. 48

Tubicola ................................... 37

Turbo ...................................... 88-89

? beneclathratus sp. n.......... 17, 88-81), 11,8

Turritella .................................. 92

burkarti sp. n...................... 17,9'2, 750

Turritellidce................................ 92

Tutotepec, Mexico, fossils from............. 21

U. 

Undulatte ...........:................ 11,20,59,60

(Jnicardium................................ 76-77

? semirotundum sp. n......... 17,18, 76,95, ISlt

?transversum sp. n.......... 17,18,76-77, 131,

varicosum............................... 76

V. 

Vaughan.T.Wayland, fossil corals described

by.............................. 34-35

Veneridfe................................... 79

Venus maloncnsis ........................... 10,65

Vernies..................................... 37

Vermetidoe ................................. 92-93-

Vermetus cornejoi................. 17, 02-93, 150

(Burtinella) cornejoi................... 92

Vertebrata .................................. 109

"Von Streeruwitz, W. H., fossils collected by. 52-53 

work of................................. 10

W.

Walcott, Charles D., acknowledgments to.. 22

Washita group, occurrence and character

of....................1....... 28,30-33

"Williams, J. W., acknowledgments to...... 22,93

Wilson, C. M., acknowledgments to........ 22

Wyschetzki, Ralph, fossils collected by.... 9-11,

52,78 

Y. 

Yucca beds, correlation of.................. 13

occurrence of........................... 13

Zuloaga, Sierra de, fossils from. 21

o