If yon do not need this report after it has served your purpose, please return it to the Geological 

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UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 186—M

A REDESCRIPTION

OF FERDINAND ROEMER'S PALEOZOIC TYPES

FROM TEXAS

BY

JOSIAH BRIDGE AND GEORGE H. GIRTY

Shorter contributions to general geology, 1936

(Pages 239-271)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1937

For sale by the Superintendent of Documents, Washington, D. C. ----- - Price 10 cents
CONTENTS

	Page 

Abstract _-___----_--___________-_________________________________________-__________--_____....___..-_..-_____ 239

Acknowledgments -__-_.---_-_____----_______________._______-_____-_________--___-___--_-_-_-_-_-___-_--.__ 239

History....._____._.___________.___________________________________________________„____________________.___ 239

Roemer's localities._----_--__---_--__.__._________________._-_________-_-____--_--___-______-_-_-.__-__-___-_ 241

Roemer's observations on the Paleozoic stratigraphy of Texas. ___._____-___-_-____--.-_-_--____--_-.__-__--_-_----_ 242

Description of species._______________________________________________________________________________________ 244

Cambrian species, by Josiah Bridge--___-_____________________________-______-_____---_-_-_--_---_-_-_--_._ 244

Brachiopoda ________________________________________________________________________________________ 244

Trilobita__..___._.___._____..._______.____.________._._._.___________.„______.___._.__________._.___ 246

Ordovician species, by Josiah Bridge_------_-_-___-__.-__---_-____---_---_---_----------_---_---_--_------- 257

Gastropoda _____-_-_-_-_-____„_________________._____________________._._______________-_______.____ 257

Carboniferous species, by George_H. Girty._________________________________________________________________ 261

ILLUSTRATIONS

Page

PLATE 66. A, Ruins of the Mission San Saba, "the old Spanish fort" of Roemer, about a mile west of Menard, Tex.; 

B, Lower part of the Wilberns formation on north bank of San Saba River at ford half a mile east of highway bridge at Camp San Saba.________________________-_--_____-______--_._--_-_--___-___---_- 244

PLATES 67-70. Ferdinand Roemer's Paleozoic types from Texas and specimens compared with them___________________ 267
A REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS

By JOSIAH BRIDGE and GEORGE H. GIRTY

ABSTRACT

This paper presents a redescription of the types of the Paleozoic 

fossils from the Central Mineral Region of Texas originally 

described by Ferdinand Roemer in 1849 and 1852, which have 

long been, inaccessible to American students. These descriptions are accompanied by new figures which include the type 

specimens, topotypes now in the United States National 

Museum, and the types of several other species that are now 

considered to be synonyms. The localities that furnished the 

original specimens have been reestablished within fairly narrow 

limits, and the stratigraphic horizons have been accurately 

determined. The type material has been compared with material from other parts of the United States, and the geographic 

range of several of the forms has been greatly extended.

ACKNOWLEDGMENTS

The authors are deeply indebted to Dr. N. Tilman, 

curator of the Museum of Geology and Paleontology, 

of the University of Bonn, Germany, for the loan of the 

type material and for the information furnished with it. 

They are also indebted to Prof. A. K. Miller, of the 

State University of Iowa, for the loan of a large number 

of specimens from the Deadwood formation of the 

Black Hills, South Dakota.

The relocation of some of the type localities and the 

collection of some of the topotype material was done 

by Josiah Bridge in 1934 in the course of an investigation aided by a grant from the Penrose Bequest of the 

Geological Society of America.

HISTORY

In 1845, 1846, arid 1847 Dr. Ferdinand Roemer, a 

noted German geologist and paleontologist, spent about 

17 months traveling in the then newly annexed State of 

Texas, gathering scientific data, and also visiting the 

various German settlements to obtain information of 

general interest to emigrants. The greater part of this 

time was spent in the Coastal Plain and the Edwards 

Plateau, which at that time were the settled portions of 

the State. In the course of this trip he spent about a 

month in the Central Mineral Region, which was then 

Indian country, and he seems to have been the first 

geologist to recognize and describe the Paleozoic rocks 

in that region.1

Roemer's first account of the geology of Texas, contained in a letter written from the field to the editor of

i See Hill, R. T., The present condition of knowledge of the geology of Texas: 

U. S. Geol. Survey Bull. 45, pp. 15-18, 1887. Comstock, T. B., Texas Geol. Survey 

1st Ann. Rept, pp. 240-241, 1889 [1890].

the American Journal of Science,2 makes no mention of 

Paleozoic rocks, but he comments on specimens of 

granite which had been brought to him from outcrops 

north of Fredericksburg.

A second preliminary paper, written after his return 

to Europe,3 gives a brief account of his trip to the San 

Saba River, describes the route traveled, notes the 

occurrence of granite, Lower Silurian (so designated 

by him) and Carboniferous rocks, and gives brief 

descriptions of them. He mentions the occurrence of 

Asaphus, Bronteus, Euomphalus, Spirijer, Productus, 

and Terebratula but gives no descriptions. In 1849 he 

published a comprehensive report on his travels in 

Texas,4 a popular account intended primarily for 

German emigrants. The greater portion of the book 

consists of the journal of his trip, together with many 

observations about the country, its resources and inhabitants. Chapters 19 to 22 describe his journey into 

the Central Mineral Region. Besides the narrative, 

there is an introductory chapter which gives a brief 

summary of the history of the State, an account of its 

geography, climate, agricultural and mineral resources, 

the history of the German settlements within the State, 

and a bibliography of books and other published articles 

relating to Texas. 4a

At the end of the book there is a scientific appendix 

in which his geologic, zoologic, and botanic observations 

are collected and summarized. The Paleozoic strata 

of the Central Mineral Region and 11 species of fossils 

found in them are described. This constitutes the 

first published report on the Paleozoic stratigraphy and 

paleontology of Texas. He lists the following Paleozoic 

species, and describes those preceded by an asterisk. 

The age designations in this list are his.

1. *Lingula acutangula, n. sp. Silurian.

2. Orthis, sp. ind. Silurian.

3. Orthis umbraculum L. v. Buch. Carboniferous.

4. Terebratula pugnus Sowerby. Carboniferous.

5. *Spirifer meusebachianus, n. sp. Carboniferous.

6. *Productus, sp. ind. Carboniferous.

7. *Productus, sp. ind. Carboniferous.

8. *Euomphalus polygyratus, n. sp. Silurian.

2 Roemer, F., A sketch of the geology of Texas: Am. Jour. Sci., 2d ser., vol. 2, pp. 

358-365, 1846.

3 Roemer, F., Contributions to the geology of Texas: Am. Jour. Sci., 2d ser., vol. 6, 

pp. 21-28, 1848.

4 Roemer, F., Texas, mit besonderer Rucksicht auf deutsche Auswanderung und 

die physischen Verhaltnisse des Landes, xiv, 464 pp., Bonn, 1849.

4a In 1935 a translation of these portions of the work, by Oswald Mueller, was 

published in San Antonio.

239
240 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

9. *Euomphalus sanctisabae, n. sp. Silurian.

10. *Pterocephalia sanctisabae, n. sp. Silurian.

11. *Pygidium of a trilobite, gen. and sp. unknown. Silurian.

The report is accompanied by a hand-colored reconnaissance map, which shows his interpretation of 

the geology of the State and also his approximate route 

from Fredericksburg to the San Saba River and return.41*

In 1852 Roomer's monumental work on the Cretaceous formations of Texas was published.5 Although 

devoted primarily to the description of the Cretaceous 

rocks and fossils, it contains an appendix in which, 

among other things, are descriptions of the Paleozoic 

strata and fossils. In all, he describes 12 species from 

the Lower Silurian (so designated by him) and Carboniferous. He redescribes the five new species of the 

previous report and adds a sixth, assigns four forms to 

previously described species, and describes two trilobites 

without referring them to a genus. These descriptions 

are accompanied by a lithographed plate on which all 

the species described, except Terebratula pugnus 

Sowerby and Productus cora D'Orbigny, are illustrated. 

The list of species, with Roemer's age designations, is 

as follows:

1. *Spirifer meusebachanus. Carboniferous.

2. *Orthis arachnoidea Philh'ps. Carboniferous.

3. Terebratula pugnus Sowerby. Carboniferous.

4. *Productus flemingii Sowerby=no. 7 in preceding list. 

Carboniferous.

5. Productus cora D'Orbigny=no. 6 in preceding list. Carboniferous.

6. *Lingula acutangula Roemer. Silurian.

7. *Euomphalus polygyratus Roemer. Silurian.

8. *Euomphalus sanctisabae Roemer. Silurian.

9. *Euomphalus gyroceras, n. sp. Silurian.

10. *Pterocephalia sanctisabae Roemer. Silurian.

11. *Cephalon and pygidium of a trilobite, genus unknown. 

Silurian.

12. *Pygidium of a trilobite, genus unknown=no. 11 of preceding list. Silurian.

All these forms except no. 3 are described in detail, 

and those preceded by an asterisk are illustrated on 

the accompanying plate.

This portion of the report was promptly reviewed 

by Barrande,6 who noted at once the twofold division 

of the Lower Silurian of Roemer, a fact which seemed 

to have escaped Roemer.

Barrande had previously examined the works of Owen 

and Hall and had concluded that the oldest faunas 

which they had obtained from the Lake Superior and 

New York regions were approximately the same and 

that they represented his Primordial (Cambrian) fauna.

4b The map is reproduced in Mueller's translation, but the text of the appendix 

is omitted. The existence of this translation was not known to the authors until 

after this paper had gone to press. All translations from "Texas" included herein are 

from the appendix, and all references to "Texas" apply to the original work.

' Eoemer, F., Die Kreidebildungen von Texas und ihre organischen Einschlusse, 

mit einem die Beschreibung von Versteinerangen aus pala'zoischen und tertiaren 

Schichten enhaltenden Anhange, und mit 11 von C. Hohe nach der Natur auf Stein 

gezeichneten Tafeln, 100 pp., Bonn, 1852.

• Barrande, J., Silur-Qebilde in Texas und am oberen See: Neues Jahrb., 1853, 

pp. 446-447.

He now compared the trilobites and the Lingvla, described by Roemer with those figured by Owen and 

Hall, noted the similarity of their stratigraphic position, 

and concluded that Roemer had found the Primordial 

fauna in Texas and that it was the equivalent of the 

lowermost Paleozoic in Wisconsin and New York. 

He also observed that the various species of Euomphalus 

which Roemer had described had not been found in 

association with the trilobites and correctly concluded 

that they indicated a younger fauna.

Roemer's two reports have been of great value to 

students of Texas geology, but they are among the 

rarities of early American geologic literature. As the 

types of the Cretaceous and Paleozoic species described 

in them are preserved in the Geological and Paleontological Museum of the University of Bonn and are 

therefore not readily accessible to American students, 

the precise identification of many of the species has long 

been a difficult matter. Notwithstanding these difficulties, the satisfactory identification of most of the 

Cretaceous species has long since been accomplished, 

but there are very few references to the Paleozoic forms 

except bibliographic citations. This may be due in 

part to the fact that, being attached to a report entitled "The Cretaceous formations of Texas," the 

Paleozoic species have escaped general notice, but it is 

largely because very little stratigraphic and paleontologic work has been done on the early Paleozoic strata 

of the State.

During the second half of the nineteenth century 

the Central Mineral Region was visited at various 

times by parties from the Texas Geological Survey, 

but, with the single exception of the work done by 

Shumard, no new paleontologic data were acquired. 

The results of these investigations have been summarized in the papers by Hill and Comstock already cited.

Actual identification of Roemer's species has been 

made by only a few paleontologists. Shumard, while 

State geologist of Texas, published a brief notice of the 

region in 1860 7 and a more detailed account the following year. In this second paper 8 he described the 

Paleozoic rocks of Burnet County in considerable detail, gave several measured sections, and described nine 

new species of fossils, all Cambrian. One of Roemer's 

unnamed trilobites was named Dikelocephcdus roemeri 

by Shumard, but none of his other species were mentioned. No illustrations accompanied these figures. 

The types are thought to have been deposited in the 

Texas State collection and, if so, were destroyed when 

the capitol burned in 1881. In 1914 Walcott 9 referred 

Dikelocephalus roemeri to Ptychoparia without discussion, and later he made it the type species of his new

i Shumard, B. F., [On Lower Silurian in Burnet County, Tex.J: St. Louis Acad. 

Sci. Trans., vol. 1, pp. 672-673,1860.

»Shumard, B. F., The Primordial zone of Texas, with descriptions of new fossils: 

Am. Jour. Sci., 2d ser., vol. 32, pp. 213-221,1861.

• Walcott, C. D., Dikelocephalus and other genera of the Dikelocephalinae: Smithsonian Misc. Coll., vol. 57, no. 13, p. 352,1914.
REDESCRIFHON OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 241

genus Elvinia.TM The name was derived from the town 

of Elvins, St. Frangois County, Mo., where the species 

also occurs, furnishing another example of the close 

geologic relationship of the two areas.

Hall and Whitfield 11 and Walcott 12 described species 

of Pterocephalia from the Eureka district, and Walcott 

also described additional species from China.13 He also 

identified Roemer's type species, P. sanctisabae, from 

material collected in Burnet County, Tex., and included this identification in faunal lists without further 

description.14 He redescribed and figured Lingula 

acutangvla, the only early Paleozoic brachiopod which 

Roemer described.16

The foregoing references appear to be the only published identifications of Roemer's species based on 

specimens, and none of the authors had access to the 

types. In 1931 the type specimens were loaned to the 

United States Geological Survey through the courtesy 

of Dr. N. Tilman, curator of the Museum of Geology 

and Paleontology at the University of Bonn, and for 

the first time it was possible to make comparisons. 

These specimens and the notes accompanying them 

have been of great assistance, and it has been possible 

to identify nearly every one of Roemer's species in the 

National Museum and Geological Survey collections. 

The study of the matrix in which the types are preserved has aided materially in assigning the type 

specimens to their proper, stratigraphic horizons.

For the various reasons stated on the preceding pages, 

it seems desirable to publish translations of the original 

descriptions and to accompany these by notes based 

not only on the types but also on collections in the 

United States National Museum and elsewhere. A 

translation of Roemer's remarks about the Paleozoic 

stratigraphy is also included, partly as a matter of 

general interest and partly because they contain more 

precise information regarding the exact localities from 

which his collections were made. An effort has been 

made to fix each locality as accurately as the statements 

in Roemer's text, supplemented by personal knowledge 

of the region, will permit.

ROEMER'S LOCALITIES

Roemer collected his Paleozoic fossils at five localities. 

Four of these are in the San Saba Valley, and the fifth 

is somewhere on the great limestone plateau that

10 Walcott, C. D., Cambrian and Lower Ozarkian trilobites: Smithsonian Misc. 

Coll., vol. 75, no. 2, p. 56,1924; vol. 75, no. 3, pp. 88, 89,1925.

» Hall, James, and Whitfleld, R. P., U. S. Geol. Expl. 40th Par. Kept., vol. 4, 

p. 221, pi. 2, figs. 4-7,1877.

18 Walcott, C. D., Paleontology of the Eureka district: U. S. Qeol. Survey Mon. 

8, pp. 58, 59, pi. 9, fig. 21,1884.

« Walcott, C. D.. Cambrian faunas of China: U. S. Nat. Mus. Proc., vol. 29, pp. 

67,68,1905; Smithsonian Misc. Coll., vol. 57, no. 4, p. 80, pi. 14, fig. 12,1911; Carnegie 

Inst. Washington Pub. 54, vol. 3, pp. 146,147, pi. 14, figs. 4, 5, 8,1913.

14 Walcott, C. D., Cambrian Brachiopoda: U. S. Qeol. Survey Mon. 51, p. 212,1912.

n Walcott, C. D., Cambrian Brachiopoda, Obolus and Lingulella, with description 

of new species: U. S. Nat. Mus. Proc., vol. 21, no. 1152, pp. 392-394, pi. 28, 1898; 

Cambrian Brachiopoda: U. S. Qeol. Survey Mon. 51, pp. 474-476, pi. 17, figs. 1, 

la-o, 1912.

forms the north border of the granite area in Llano 

County. An effort has been made by Bridge to 

reestablish these localities in order to secure topotype 

material. A study of Roemer's narrative, followed by 

field investigations in the fall of 1934, has enabled this 

to be done with a reasonable degree of certainty for 

four of the localities.

It is a fairly safe assumption that the present roads 

were established along former Indian trails, and that 

many of them have not been materially relocated. 

This is particularly true of the principal crossings of 

the larger rivers, the greater number of which are 

still unbridged.

Roemer states that his party traveled northwestward 

from Fredericksburg a distance of about 80 miles to 

reach the San Saba River. In so doing, it seems fairly 

certain that he followed the approximate course of the 

present Fredericksburg, Mason, and Brady highway 

to a point near Mason and then took a more northerly 

direction, reaching the San Saba Valley in the vicinity 

of Voca. The distance which he gives is somewhat 

greater than that of the present route, but it must be 

remembered that all of his mileage is estimated, and 

also that he must have done considerable meandering 

to and fro to get over some of the rougher parts of the 

country. His brief descriptions of the geology along 

this route tally very well with present observations. 

He speaks of passing directly from the Cretaceous 

rocks onto a sandstone (Trinity or Hickory, or both), 

and from this onto the granite, without noting the 

presence of the "Silurian" (Cap Mountain, Wilberns, 

and Ellenburger) limestones, before reaching the Llano 

River. These conditions exist along the general course 

of the Fredericksburg-Mason road. The Cambrian 

limestones, though not entirely missing, are strongly 

overlapped by the Cretaceous rocks and are easily 

overlooked.

Roemer states that after crossing the Llano River his 

party traveled over granite for about 20 miles and then 

crossed a long, narrow, steep-sided eastward-trending 

ridge of limestone 16 which rested upon the granite, and 

that in another 12 miles they reached the San Saba 

River. This ridge is plainly the long tongue of Cambrian and Cretaceous rocks that crosses the present 

highway about 6 miles north of Mason He makes no 

comment about the age of the limestones in this ridge 

at this point in the narrative, but in another place 17 

he states that the first Silurian limestones were observed on the journey between the Llano and San 

Saba Rivers; he notes they were full of trilobite remains but does not state that any of his specimens 

came from this place. He does not mention the overlying Cretaceous rocks at this point, but he probably 

observed them. About the only place where he could

w Roemer, F., Texas, p. 289,1849. 

«Idem, p. 388.
242 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

have found Cambrian limestones along this route between the Llano and San Saba Rivers is on the south 

side of this ridge where the present Mason-Katemcy 

road crosses it. Elsewhere along this same ridge the 

Cretaceous rests on granite, so that it seems fairly certain that he crossed it at about this point. After crossing the ridge, the party seems to have turned slightly 

east of north, reaching the San Saba River somewhere 

between Voca and the mouth of Lost Creek. After 

halting here for a day they crossed the river, made 

two short marches along the north bank, and made 

their third camp in the San Saba Valley at a point said 

to be about 14 miles upstream from the point at which 

they had first reached the river. They were probably 

close to Camp San Saba, although the distance that 

Roemer gives is too great. All the Cambrian species 

which Roemer describes were collected while at this 

camp. The greater part of these Cambrian fossils 

come from the Camaraspis zone, which occurs in the 

lower portion of the Wilberns formation. This zone is 

exposed along the San Saba River about a mile east of 

the present highway crossing, at a ford, and as this is 

the only place in this part of the San Saba Valley where 

this zone is exposed, it seems certain that Roemer must 

have obtained his fossils from this particular belt of 

outcrop. In 1934 Bridge collected Pterocephalia sanctisabae, Elmnia roemeri, and other characteristic speciss 

from beds exposed at water level on the north side of 

the San Saba River just below the ford half a mile 

northeast of Camp San Saba and 1 mile east of the new 

bridge on United States Highway 385 (pi. 66, B}. Five 

or six feet above this zone are beds carrying Eoorthis 

remnichia texana in great abundance, which may be the 

"form similar to Orthis" that he mentions. The lithology of the beds carrying Pterocephalia is identical 

with that of the fragment containing Roemer's types.

The expedition continued along the north bank of 

the river until it reached the old Spanish mission and 

fort near the present town of Menard (pi. 66, A) and 

after spending a day or so in that neighborhood crossed 

the river and returned along the south bank. Roemer 

noted the occurrence of Carboniferous strata about 15 

to 20 miles downstream from the fort and one Carboniferous species, Spirifer meusebachanus, was collected 

here from beds now placed in the Canyon group. 18 He 

also obtained two "Silurian" species, Eccyliomphalus 

gyroceras and Ophileta polygyrata, from this same general locality.

In 1934 Bridge collected Eccyliomphalus gyroceras 

and Ophileta polygyrata from the white limestone that 

forms the base of the Ellenburger limestone in this 

area, in a small ravine on the south side of the San 

Saba River half a mile east of the north-south highway 

that parallels the Mason-Menard County line. These 

species are abundant at this place and were found at

is Roemer, F., Texas, pp. 314, 420, 421, 1849; Kreidebildungen, pp. 7, 88, 1852.

several places between this ravine and the ford at the 

Blockhouse ranch, about a mile farther east (downstream), and the lithology of the strata containing them 

is similar to the matrix of Roemer's specimens. 

These are the most westerly exposures of this part of 

the Ellenburger in the San Saba Valley, and, as they 

are at about the proper distance downstream from 

Menard, it would seem that Roemer's specimens came 

from this general locality.

The remaining "Silurian" specimen, Lecanospira 

sanctisabae, was collected on the first day of the return 

journey from the San Saba Valley. The party had 

followed the river downstream, past the point where 

they first reached it, until the valley reentered the Carboniferous rocks. They seem to have reached a point a 

few miles west of the present town of San Saba. Here 

they turned almost due south and returned to Fredericksburg. Although Roemer describes the route fairly 

well, there are no conspicuous landmarks along it which 

enable it to be located exactly. However, they must 

have crossed the great plateau formed by the Ellenburger limestone, which bounds the granite area on the 

north, on about the line of the present Pontotoc-San 

Saba road. Lecanospira sanctisabae is a characteristic 

fossil in beds of Roubidoux age in the Ellenburger, and 

specimens have been collected at this horizon along the 

above-mentioned road on the divide at the headwaters 

of Wallace Creek, latitude 31°06', longitude 98°51'.19 

This is probably the belt from which Roemer's specimens came, but the exact locality is of course uncertain. 

The fifth locality, which is the one from which the 

greater number of Carboniferous specimens came, has 

not been definitely located. The narrative places it 

near the site of their last camp in the San Saba Valley, 

about 35 miles downstream from the spot where the 

Cambrian collections were made. This would place it 

somewhere in the vicinity of San Saba. It is described 

as being in a small tributary valley on the left bank of 

the river.

ROEMER'S OBSERVATIONS ON THE PALEOZOIC 

STRATIGRAPHY OF TEXAS

Roemer's observations on the Paleozoic stratigraphy 

of Texas are brief. In the following translations, page 

references in parentheses refer to other portions of the 

original text, and phrases in brackets are interpolations 

by the present writers that are necessary in order to 

clarify certain statements:

THE OLDEB OK PALEOZOIC BOCKS

In this broad region, the northwestern portion of which is covered by Cretaceous rocks, there is a relatively small area on the 

right bank of the Colorado River between the Pedernales and 

San Saba Rivers in which ancient stratified and massive crystalline rocks occur. Rocks of this type were first observed on the 

journey northward from the Llano to the San Saba River. 

These are impure, crumbly, partly crystalline gray limestones

>" See soil map of San Saba County, U. S. Dept. Agr., Bur. Soil?, 1916.
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 243

in horizontal or gently tilted strata. They are surrounded by 

[rest on] granite. They are full of organic remains, the most 

abundant and characteristic of which are various species of 

trilobites. A few specimens of Orthis were also noted.

This same impure gray crystalline limestone was also observed 

in the valley of the San Saba River about 40 English miles below 

the old Spanish fort (p. 299). Here [also] trilobites are the most 

abundant fossils. One of these in particular (Pterocephalia 

sanctisabae, n. sp.) is readily distinguished from all known trilobite genera by broad leaf-like expansion [of the margins] of the 

cephalon and pygidium. The trilobites, although differing from 

known genera, are more closely related to Silurian types than 

to those of any other period of the Paleozoic. Associated with 

these trilobites are an Orthis and a species of Lingula (L. acutangula, n. sp.).

Farther upstream in the San Saba Valley a hard yellowish-gray 

limestone was found overlying [the trilobite beds]. From the 

few fossils which were obtained from it, it must also be of Silurian age.

Rocks that must be of Silurian age were also found downstream 

from the first-mentioned locality. This is a very tough, cherty 

limestone, filled with small quartz druses, and at this locality it 

forms barren, stony heights on both sides of the river (p. 317). 

Almost no fossils were observed, except a form of Euomphalus 

(E. sanctisabae, n. sp.), and this is different from most of the 

known Silurian species.

Another division of Paleozoic rocks was also found in association with the Silurian rocks in the San Saba Valley.

About 60 English miles below the old Spanish fort, in a small 

valley tributary to the San Saba, are strongly upturned ledges 

of a hard, black, massive limestone which contain large kidneyshaped masses of dark chert. This limestone is profusely 

fossiliferous, and the fossils show plainly that it is of Carboniferous age (p. 318). The most abundant fossil is a small species 

of Productus which, if not identical with, is at least very closely 

related to a form found abundantly in the Carboniferous limestone of Illinois. Associated with this species is Orthis umbraculum L. v. Buch (Spirifera crenistriata Sowerby), Terebratula 

pugnus Sowerby, and a finely striated Productus closely related 

to P. cora D'Orbigny. A single hand specimen of this limestone 

which I brought back with me resembles the black limestone of 

Vis6 so closely in its outward appearance as to be easily confused 

with it.

About 20 miles below the old Spanish fort a gray limestone 

containing large masses of black chert was found on the right 

bank of the river. From this several specimens of a Spirifer 

(S. meusebachanus, n. sp.) were collected. This species with 

its many divided and fasciculated ribs is a distinctive Carboniferous form and in many ways is most closely related to 

Spirifer tasmani Morris,20 from Van Diemen's Land [Tasmania].

This universal distribution of species of the Carboniferous 

period even to the remotest portions of the earth furnishes a 

new illustration of the lack of climatic differences in the ancient 

geologic periods.

Not a trace of Devonian strata was found, and this is in 

complete accord with other observations. For example, as far 

as is known, there are no strata of Devonian age in that portion 

of North America which is west of the Mississippi River. This 

is particularly true along the Meramec River in Missouri, where, 

without a single exception, the Carboniferous limestone rests 

directly on Silurian strata. This is proved by the faunas of the 

two series of ancient rocks, which contain nothing that could be 

interpreted as the equivalent of the Devonian period.

The most westerly point at which rocks of the Devonian 

period are definitely known is at the Falls of the Ohio at Louis20 See Buch, L. v., Die Bareninsel, nach Keilhau geognostisch beschrieben, p, n, 

figs. 3a, b, Berlin, 1847.

ville. At this place they are so thin and so closely related to the 

underlying Silurian by rocks which from their fossil content 

may be regarded as a transition series that their complete 

disappearance farther west is already indicated to a certain 

degree.—Texas, pp. 388-390, 1849.

OLDER OR PALEOZOIC BOCKS

No rocks belonging to the periods immediately preceding the 

Cretaceous are known in Texas. This applies in particular to 

the Jurassic formations, whose absence throughout the entire continent of North America was pointed out many years ago by 

Leopold von Buch, and of which not a trace has been definitely 

reported as a result of several investigations since that time. 

[A long footnote summarizes the results of these investigations.]

Just a little is definitely known of the occurrence of Triassic 

strata in Texas. The single observation on the rocks on the 

upper course of the Red River, in Falconer's journal,21 indicates 

that possibly these rocks belong to this period. On the upper 

course of the Red River and westward from the Wichita River 

this traveler found strata of red sandstone interbedded with 

fibrous gypsum covering a broad area. Later on, in going westward from Cross Timbers, he observed the deep-red color of the 

water and the sand in all the rivers and brooks which he crossed, 

also a noticeable salt content in all standing and running water. 

The red coler and salt and gypsum content of the rocks on the 

upper part of the Red River, which undoubtedly owes its name 

and color to them, may also serve to show its equivalence with 

the Bunter sandstone of Europe. However, such correlations, 

based entirely on lithologic observations and without knowledge 

of stratigraphic relationship and contained fossils, are always 

untrustworthy.

On the other hand, rocks of the older or Paleozoic period are 

definitely known in Texas. Not only Silurian strata but also 

those belonging to the Carboniferous have been definitely recognized by their paleontologic character. The older rocks are 

found in the mountainous portion of Texas, particularly in the 

region between the Llano and San Saba Rivers. They occur 

here together with massive crystalline rocks in a few comparatively small areas and appear to be completely encircled by 

Cretaceous rocks.22

1. In the region between the Llano and San Saba Rivers the 

first Silurian rocks were seen about 70 English miles northwest 

of the German settlement of Fredericksburg, on the Pedernales. 

At this place they are completely surrounded by granite and 

occur in a very narrow tongue of land extending from westsouthwest to east-northeast. The rock is an impure, partly 

crystalline, much weathered and decomposed limestone in 

slightly dipping or almost horizontal layers. It is completely 

filled with the head and tail shields of characteristic trilobites. 

This same impure limestone was also found in the San Saba 

Valley about 40 miles below the old Spanish fort (Texas, p. 299). 

Here also the strata are essentially horizontal. The limestone 

contains many green grains of iron silicate. Although firm and 

compact while in the ledge, the strong crystalline structure of the 

rock causes the surface of broken fragments to crumble readily. 

The entire mass of the limestone is filled with countless detached 

trilobite shields, almost to the total exclusion of other organic 

remains. These trilobites appear to belong to genera and 

species which, while different from known forms, most closely 

resemble Silurian types. From the confused mass of fragments 

the following species can be separated:

21 Falconer, Thomas, Notes on a journey through Texas and New Mexico in the 

years 1841 and 1842: Royal Qeog. Soc. London Jour., vol. 13, p. 210, 1842.

22 The distribution of these older rocks is shown on the geologic map that accompanies the general report on Texas. The boundary between the Carboniferous and 

Silurian strata is not shown, the few poor observations available not being sufl&cient 

to permit this being done.—J. B.
244 SHORTER CONTBIBTJTIONS TO GENERAL GEOLOGY, 1936

(1) Pterocephalid sanctisabae, n. sp. A species that is readily 

distinguished from other trilobites by the remarkable leaflike 

expansion of the cephalon and pygidium.

(2) Pygidium of an otherwise unknown form which is remarkable because of the great height of the axis.

(3) Pygidium and cephalon of a species which resembles 

Calymene in the lateral notching of the glabella but which, however, belongs to an entirely different genus. 

, The only other fossils found here were a Lingula (L. acutangula, n. sp.) related in shape to L. cuneata Hall, from the Medina 

sandstone of Silurian age at Lockport, N. Y., and an Orthis 

closely resembling Orthis testudinaria Dalman,

Lastly, there is another stratigraphic series which is to be 

classified as Silurian. This is a white or bright-gray, tough, 

cherty limestone containing many small quartz druses. It 

forms the barren rock-strewn uplands that are found along 

both sides of the San Saba River in the middle portion of its 

course (Texas, p. 317). The only fossil that was observed in 

great abundance was a species of Eupmphalus (E. polygyratus, 

n. sp.) 2S but this does not definitely determine the Silurian age 

of these rocks, because, on the one hand, the Euomphalus shows 

great differences from known Silurian species, and, on the other 

hand, the petrographic character of the rock gives no suggestion 

that they belong to any other portion of the older rocks. 

. 2. Carboniferous limestone was definitely recognized at two 

places in the San Saba Valley. The first locality was about on 

the right bank of the river about 20 miles below the old Spanish 

fort (Texas, p. 314). In this locality it consists of a wellstratified tough yellowish-gray limestone which contains large 

masses of black chert. Its identification as Carboniferous is 

determined particularly by the presence of a Spirifer (S. meusebachanus, n. sp.) which belongs to a group of Carboniferous 

species distinguished by the fasiculate arrangement of the ribs 

and which is very closely related to another Spirifer (S. tasmani 

Morris) from Van Diem en's Land.

The Carboniferous was just as definitely identified at a 

second locality farther down the valley and about 60 miles below 

the old Spanish fort (Texas, p. 389). In a small tributary valley 

on the west side of the San Saba River are heavy, steeply dipping 

ledges of tough black limestone containing streaks of dark chert 

a foot in thickness. This limestone is rich in fossils, among 

which the following species were recognized:

Productus flemingii Sowerby, especially abundant.

Productus cora D'Orbigny.

Terebratula pugnus Sowerby.

Orthis arachnoidea Phillips.

These fossils leave no doubt as to the age of this rock. A single 

fossiliferous fragment of this limestone which I brought back with 

me resembles hand specimens of European Carboniferous limestones and is hardly to be distinguished from those from Vise", on 

the Maas. * * *—Kreidebildungen, pp. 86-87, 1852.

DESCRIPTION OF SPECIES

The material received from Bonn consists of 20 lots, 

numbered 1 to 20. These numbers have nothing to 

do with the numbers assigned to the specimens in 

either of Roemer's papers. Each lot consists of a 

single fragment of rock containing one or more fossils, 

except lot 4, which contains two fragments. Each lot 

is accompanied by a label giving the name and many of 

them other information about the specimen. These

a Evidently a misprint. E. sanctisabae is elsewhere said to be abundant here. 

E. .polygyratus was said to have been collected some 40 miles or so farther southwest, 

and Roemer notes that only a single specimen was obtained. (See Texas, pp. 314, 

421; also Kreidebildungen, pp. 91, 339.)—J. B.

notes show which specimens served as the principal 

sources of the original illustrations, which were used to 

supply supplementary details, and which were considered by Roemer to be the types, This information 

has been incorporated in the revised descriptions.

CAMBRIAN SPECIES

By JOSIAH BRIDGE

BRACHIOPODA 

Lingulepis acutangula (Roemer)

Plate 67, figures lOa, b; plate 68, figures 1-6

1849. Lingula acutangula Roemer, Texas, p. 420.

1852. Lingula acutangula Roemer, Die Kreidebildungen von

Texas, p. 90, pi. 11, figs. lOa, b.

1852. Lingula pinnaformis Owen, Geological Survey of Wisconsin, Iowa, and Minnesota, p. 583, pi. Ib, figs. 4, 6, 8. 

(For synonymy of Lingulepis pinnaformis see Walcott, 

U. S. Geol. Survey Mon. 51, pp. 545-546, 1912. The 

following citations refer only to Roemer's types and to 

forms identified as L. acutangula.) 

1889. Lingula acutangula. Miller, North American geology and

paleontology, p. 349. 

1897. Lingulepis acutangulus. Schuehert, U. S. Geol. SuTvey

Bull. 87, p. 259 (generic reference).

1933. Lingulella acutangula. Bridge, in Sellards, Adkins, and 

Plummer, Texas Univ. Bull. 3232, p. 231, pi. 2, fig. 9 

[not fig. 8]. (No description; fig. 9 is the holotype.) 

Not 1898, Obolus (Lingulella) acutangulus. Walcott, U. S. Nat. 

Mus. Proc., vol. 21, pp. 392, 394, pi. 27, fig. 6, pi. 

28, figs. 1, 2. 

Not 1912. Lingulella acutangula. Walcott, U. S. Geol. Survey

Mon. 51, p. 474, pL 17, figs, 1, la-lo.

Not 1931. Lingulella acutangula. Dake, Missouri Bur, Geology 

and Mines, 2d ser., vol. 23, pp. 61, 86, 87, 96 (cited 

in fauna! lists)*

ORIGINAL DESCRIPTIONS

1. Lingula acutangula, n. sp. Shell ovate, subtriangular, produced anteriorly into an acute beak, posteriorly rounded.2*

Allied to L. cuneata Conrad (see Hall, Geology of New York, 

pt. 4, pi. 1, no. 2, fig. 5), from the Medina sandstone at Lockport. From the gray Silurian limestone with abundant trilobite remains at the locality described on page 299.—TexaSj p. 420.

6. Lingula acutangula 

Plate 11, figures 10, lOa, lOb 

Lingula acutangula F. Roemer, Texas, p. 420. 

Length 8'", width 6'"

Shell ovate, subtriangular, short, slightly convex, the posterior end 

rounded, the anterior end produced into a narrow beak. The shell 

is oval, almost triangular, short, slightly convex, posteriorly 

rounded, the anterior end drawn out into a sharply pointed beak.

At a few places on the upper surface of damaged shells one 

can plainly see the laminated structure of the shell, which is made 

up of thin plates laid one above the other. The chitinous condition, which is characteristic of the genus and which is usually 

well preserved, is less commonly shown.

«In all descriptions tne portions in italics are in Latin in the original texts. Phrases 

in brackets indicate additions and interpretations by the translator.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPEE 186 PLATE 66

A. RUINS OF THE MISSION SAN SARA, "THE OLD SPANISH FORT" OF ROEMER, ABOUT A MILE WEST OF MENARD, TEX.

B. LOWER PART OF THE WILBERNS FORMATION ON NORTH BANK OF SAN SAB A RIVER AT FORD HALF A MILE EAST OF HIGHWAY BRIDGE

AT CAMP SAN SABA.

feEDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 245

In its outward appearance this form resembles Lingula cuneata 

Conrad (see Hall, Geology of New York, pt. 4, pi. 1, no. 2, fig. 

5), from the Medina sandstone at Lockport. However, when 

compared with specimens of the New York form which are 

before me, it is to be distinguished by its much sharper beak.

Occurrence: Common in the gray, brightly crystalline Silurian 

limestone, with abundant trilobites in the San Saba Valley.

Description of the figures: Figure lOa, view of the outer surface; 

figure lOb, profile view.—Kreidebildungen, p. 90.

NOTES ON THE TYPE SPECIMEN

A comparison of the type specimen with the types of 

the well-known Lingulepis pinnaformis (Owen) shows 

plainly that they are the same species, and as Koemer's 

name has priority, L. pinnaformis (Owen) becomes a 

synonym of L. acutangula (Roemer).

Roemer's material consists of a single imperfect 

specimen (no. 20) on a fragment of gray, coarsely 

crystalline glauconitic limestone. The matrix is identical with that in which the trilobites are preserved. 

It also contains a few fragments of trilobite tests, none 

of which are complete enough for identification.

The specimen is a somewhat exfoliated ventral valve, 

which lacks the extreme tip of the beak and most of the 

anterior and left anterolateral margin. In its present 

condition it is 16 millimeters long and 13 millimeters 

wide, but when complete its dimensions must have been 

approximately 19 by 16 millimeters. These measurements agree very closely with Roemer's (8 by 6 lines) 

and constitute additional evidence in support of the 

idea that this was his type specimen.

The original figure (pi. 67, fig. lOa), is much narrower 

than the type specimen and shows a sharp angulation 

at the junction of the anterolateral and posterolateral 

margins, which does not exist on the type specimen. 

In view of these differences it is not at all surprising 

that this species has been misidentified by subsequent 

workers. The convexity of the valve is 2.8 millimeters.

The anterior end of the shell, to judge from the 

course of the growth lines, was evidently rather blunt 

and broadly rounded, the anterior margin passing into 

the anterolateral margins without any sharp angulation.25 The posterolateral margins are slightly concave 

and meet at the beak in an angle of 78°. Where the 

outer surface is preserved, it is ornamented by fine, 

concentric, somewhat irregular growth lines.

The shell itself is about 0.2 millimeter thick and is 

composed of white crystalline calcite. The inner surface, where exposed by the exfoliation of the shell, is 

marked by strong radiating ribs, crossed by heavier, 

widely spaced concentric lines. In the middle of the 

shell about three of the ribs occur in the space of 1 

millimeter, whereas the concentric lines are spaced 

about 1 millimeter apart. Both sets become more 

closely spaced toward the beak. The muscle scars are 

not exposed.

25 In Roemer's description the terms "anterior" and "posterior" are used in the 

opposite sense from present usage.

79717—37———2

When compared with the types of Lingulepis pinnaformis the similarity of form and size is at once apparent. The outline of the valve and the relative proportions are practically identical. Roemer's specimen is 

slightly larger than the largest of Owen's types (pi. 68, 

fig. 6), but specimens of this size are common in areas 

where the species is abundant. The measurements of 

three ventral valves among Owen's types are, length, 

16, 15.5, and 13 millimeters; width, 12.5, 13, and 11 

millimeters; convexity, 2.2, 2.2, and 2 millimeters. 

These specimens also display the faint radial internal 

markings which show so plainly on Roemer's specimen.

The surprising thing about this identification is the 

fact that Lingulepis pinnaformis has not been recorded 

from Texas. Walcott records L. acuminata (which he 

considered to be the same as L. pinnaformis) from four 

localities in the Central Mineral Region and also from 

El Paso.26 None of these appear to belong to L. 

acutangula; in fact, they are all narrower and more 

sharply acuminate than the forms which he referred to 

this species. Nor does the species appear in any of the 

collections made by Dake and the writer.

The species has been identified in a collection from 

the Hickory (?) sandstone 27 at a point about a quarter 

of a mile east of Sandy post office, Blanco County. 

Most of the material from this locality is fragmentary, 

but several good specimens that agree very closely with 

Roemer's specimen were obtained. The species is 

evidently not common over the entire area, but it may 

be locally abundant, as in this locality.

COMPAEISON WITH OTHEE SPECIMENS EEFEERED TO LINGULEPIS 

ACUTANGULA

There have been few references to this species. 

Schuchert changed the generic reference to Lingulepis 

but did not discuss the species. In 1898 Walcott 

referred to the species and published illustrations of a 

Texas form which he identified as Lingulella acutangulus. 

In his monograph on Cambrian Brachiopoda Walcott 

describes this species in detail and illustrated it with a 

plate containing not only the illustrations of his previous 

paper but also many others. All these specimens came 

from three localities in the Central Mineral Region, and 

it is extremely abundant in these localities and many 

others in that area.

The most obvious difference between this form and 

Roemer's specimen is in the proportion of length to 

width. In Roemer's specimen this is approximately 

10 : 8.5, but in Walcott's specimens it averages 10 : 6.75. 

All of Walcott's specimens, both figured and unfigured, 

are smaller than Roemer's. The largest specimen 

(Mon. 51, pi. 17, fig. le) is 14.5 millimeters long. 

Another specimen (pi. 17, fig. 1) is nearly as large, but

28 Walcott, C. D., Cambrian Brachiopoda: U. S. Qeol. Survey Mon. 51, pp. 

544-550, pi. 42, figs. Ik-lo, 1912.

2r These outcrops have not been visited, and it L« not definitely known whether 

they are actually Hickory or the Lion Mountain sandstone member of the Cap 

Mountain.
246 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

the average length of the ventral valve is between 9 and 

10 millimeters.

Edwards,28 who has restudied nearly all of Walcott's 

material in preparation of a monograph on the Cambrian brachiopods of Wisconsin, refers Lingulella 

acutangula Walcott to L. arguta Walcott, and this seems 

to be the correct assignment. The various references 

to L. acutangula subsequent to the publication of 

Walcott's monograph (with the exception of fig. 9, 

pi. 2, Texas Univ. Bull. 3232, 1933) are also assignable 

to L. arguta.

It is entirely possible that the very broad forms which 

are here designated Lingulepis acutangula represent the 

extremely mature stage of a form that is somewhat 

narrower in the normal adult stage, for the successive 

growth increments tend to increase the width of the 

shell more rapidly than the length. If this is true, both 

types should be found more or less intimately associated 

at all localities. This is not the case. Lingulepis 

acutangula is not a common form. It is not common 

at any of the Cambrian localities in central Texas that 

have been examined, and as yet it has not been found 

in association with a narrow form such as L. arguta. 

On the other hand, where it is extremely abundant, as 

for example in the Eau Claire formation of southern 

Wisconsin, it fills certain strata to the almost total 

exclusion of other forms. A certain amount of individual variation is observable when large numbers of 

specimens belonging to this species are compared, and 

it is quite possible to divide them into several groups 

that might be termed species or varieties, but such a 

course would serve no useful purpose, as it would have 

neither stratigraphic nor geographic significance.

OCCURRENCE

The type specimen came from the San Saba Valley 

at a point about half a mile east of Camp San Saba, 

McCulloch County. The horizon is basal Wilberns. 

The species also occurs in a sandstone thought to be 

the Hickory in the valley of Hickory Creek about a 

quarter of a mile east of Sandy post office, Blanco 

County.

"Orthis" sp. undet.

ORIGINAL DESCRIPTION

2. Orlhis sp. ind. Related to 0. testudinaria Dalman. Found 

in association with the foregoing species [L. acutangula].—Texas, 

p. 420.

REMARKS

This form was neither described nor figured in the 

Kreidebildungen, although it is mentioned at several 

places. No specimens answering to its description 

were included in the shipment from Bonn. Roemer 

evidently had in mind one or more of the coarsely 

ribbed brachiopods such as Billingsella coloradoensis,

2 » Edwards, Ira, unpublished manuscript.

Eoorthis wichitaensis, E. indianola, or E. remnichia 

texana, all of which are more or less abundant in the 

Upper Cambrian of this area. According to Walcott's 

faunal lists, B. coloradoensis is almost invariably associated with Lingulella arguta,29 whereas the other 

forms occur at a higher horizon, in the base of the 

Wilberns formation. Eoorthis remnichia texana is extremely abundant at the locality east of Camp San 

Saba in a bed about 5 feet above the beds carrying 

Pterocephalia.

TRILOBITA

Genus PTEROCEPHALIA Roemer 

Pterocephalia sanctisabae Roemer

Plate 67, figures la-d; plate 68,'figures 7-43

1849. Pterocephalia sanctisabae Roemer, Texas, p. 421.

1852. Pterocephalia sanctisabae Roemer, Die Kreidebildungen

von Texas, p. 92, pi. 11, figs. la-d. 

1877. Conocephalites (Pterocephalus) laticeps Hall and Whitfield,

U. S. Geol. Expl. 40th Par. Rept., vol. 4, p. 226, pi. 2,

fig. 37.

1884. Ptychoparia (Pterocephalus) laticeps. Walcott, Paleontology of the Eureka district: U. S. Geol. Survey Mon. 8,

p. 59. 

1889. Plerocephalia laticeps. Miller, North American geology

and paleontology, p. 564.

1889. Pterocephalia sanctisabae. Miller, idem, p. 564. 

1933. Pterocephalia sanctisabae. Bridge, in Sellards, Adkins, and

Plummer, Texas Univ. Bull. 3232, p. 232, pi. 2, figs.

26, 27. (Types refigured without description.)

ORIGINAL DESCRIPTIONS

10. Pterocephalia sanctisabae, n. sp. This species undoubtedly 

belongs to a new genus which I here name Pterocephalia on account of the remarkable extremely thin, leaf-like expansion of 

the cranidium. The diagnosis of this form is as follows: Head 

expanded in a leaf-like plate in front and on both sides of the glabella. 

Glabella with four incised furrows on eaeh side; tail bordered by a 

broad, rounded, leaf-like depressed margin.

The thorax is not known, and therefore association of this 

pygidium and cranidium is questionable; however, on account of 

the analogous structure of the two it is extremely probable.

This species is widely separated from all other known trilobitas 

by this leaf-like expansion of the cranidium and pygidium. It is 

common in a gray Silurian limestone at the locality previously 

described on page 299.—Texas, p. 421.

This preliminary description was greatly expanded 

in the "Kreidebildungen" and was accompanied by 

several excellent illustrations.

10. Pterocephalia sanctisabae

Plate 11, figures la-d 

Pterocephalia sanctisabae F. Roemer, Texas, p. 421.

Certain weathered layers of gray limestone outcropping in the 

Sac Saba Valley are filled with trilobite remains to the almost 

total exclusion of other types of animal life. Noteworthy among 

these is a cephalon which appears here for the first time and which 

does not seem to be related to any known genus of trilobites. It 

differs especially in the very wide, leaf-like, thin expansion of the

29 Walcott, C. D., Cambrian Brachiopoda: U. S. Qeol. Survey Mon. 51, pp. 212- 

213, 1912.
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 247

anterior portion of the cephalon. A careful examination has 

made it possible to determine the generic characters of the trilobite to which this head belongs. A pygidium is also referred 

to the same genus with a considerable degree of certainty. The 

reason for including this pygidium in the genus lies in the analogous broad, leaf-like expansion which it possesses, in the large 

number of pygidia which are found, and in the absence of any 

other cephala in these strata with which it could be associated.

The cephalon figured on plate 11, figures la and Ib, which is 

one of four identical specimens now before me, will be described 

first. On the whole it is very flat, in the anterior portion 

somewhat concave. The length is somewhat greater than the 

width, but in regard to this statement it should be borne in 

mind that the free cheeks which lie outside of the facial suture 

are missing on all the examples before me. The glabella narrows anteriorly and is not half as long as the cephalon. On the 

sides it is separated from the fixed cheeks by a clearly defined 

furrow. At the anterior end it is separated from the broad 

winglike anterior expansion of the cephalon by a shallow furrow, 

ornamented with many small, delicate radial wrinkles. The 

occipital furrow is well developed and is deeper on the sides than 

in the middle. On each side are two sharp glabellar furrows 

directed posteriorly, which do not join across the center but 

which occupy about one-third the width of the glabella. There 

is also a third pair, which are weaker, shorter, and almost 

horizontal. The center of the occipital ring is raised into a 

short blunt knob.

The fixed cheeks on each side of the glabella are strongly 

arched from the margin of the glabella to the facial suture. 

The course of the facial suture is not as plain as is indicated in 

the figure. A somewhat elevated and prominent portion of the 

border is to be considered as the palpebral lobe—that is, that 

portion of the cranidium which carries the eye tubercules. The 

free cheeks are not known, but from the shape of the cranidium 

and the width of the pygidium assigned to it they are thought 

to be narrow and do not essentially affect the shape of the 

cranidium. The occipital furrow on the fixed cheeks is plainly 

visible but is not as deep as it is upon the glabella. The broad, 

flat, leaf-like expansion on the anterior portion of the cranidium 

is almost plane but is slightly concave from the anterior to the 

posterior end. The semicircular anterior margin has a fine 

raised line parallel to it at a distance of about one line. The 

upper surface of this leaf-like expansion as ordinarily preserved 

is smooth, but in a single specimen in which the outer shell layer 

is largely destroyed the surface is covered with very fine, sharp, 

anastomosing raised lines, similar in character to those which 

are found in many other trilobite genera—for example, Bronteus. 

No traces of the dorsal furrow that bounds the glabella are to 

be found on this leaf-like expansion. When the cephalon just 

described is compared with the typical trilobite head, it appears 

that the entire leaf-like expansion of the anterior portion of the 

cephalon must be regarded as an extraordinary widening of the 

frontal border (limbus), for there is nothing else except the 

frontal border in front of the sharply defined glabella.

The pygidium assigned to the cephalon just described possesses 

the following characteristics. It is semicircular, with the 

anterior corners rounded, the anterior and central portions 

strongly elevated, while the lateral and posterior edges are 

extended into a smooth, broad, paper-thin lamella. The axis, 

which is small in comparison to the entire pygidium, narrows 

posteriorly and terminates slightly beyond the half-length of 

the pygidium. It is strongly elevated, almost half-cylindrical, 

and carries 9 to 10 well-marked annulations. The upper surface of the pygidium slopes away from both sides of the axis 

gradually at first and then descends steeply to the flat marginal 

expansion. The elevated laterial slopes of the pygidium lying 

next to the axis are ornamented with slightly raised, gently 

curving pleurae, one for each segment of the axis. They

flatten out and vanish when they reach the flat marginal expansion. This flattened marginal border of the pygidium is ornamented with extremely fine, sharp, raised lines similar to those 

found on the anterior border of the cephalon. It is otherwise 

smooth.

Little is known of the thorax, at least in association with 

either the cephalon or the pygidium. In one piece of rock a 

single incomplete segment which probably belongs to this form 

has been found lying close to the cephalon. It is thin, very 

smooth, 1.5 lines wide, weakly arched, and the ends are blunt 

and obliquely truncate.

From the foregoing description, the generic characters may 

be summed up as follows:

Pterocephalia?0 n. gen.

Head semicircular, thin, almost plane, the portion lying in front 

of the glabella expanded into a long thin lamina.

Glabella subtrigonal, narrowest anteriorly; drcumglabellar furrow 

continuous; glabellar furrows in three pairs, of which two are 

longer and obliquely directed, and one, the anterior pair, horizontal 

and shorter, not continuous.

Facial suture widely separated anteriorly, forming an almost 

straight line from the frontal to the occipital margin.

Thoracic segments smooth, obliquely truncated on each end, 

number (?).

Pygidium semicircular, convex, bordered by a wide, thin plate 

which is especially produced posteriorly; axis elevated, narrow, 

composed of 9 to 10 segments; pleura distinctly incurved, becoming 

short and disappearing posteriorly.

One species: Pterocephalia sanctisabae.

Common in the crystalline gray limestone carrying abundant 

trilobite remains which occurs in the San Saba Valley.

Description of figures: Figure la, view of cephalon from above; 

figure Ib, view of cephalon in profile; figure Ic, view of pygidium 

from above; figure Id, view of pygidium in profile.—Kreidebildungen, p. 92.

NOTES ON THE TYPE SPECIMENS

The type material consists of a fragment of grayishwhite, coarsely crystalline limestone containing two 

cranidia (no. 1); and four other fragments of the same 

type of rock containing incomplete pygidia (nos. 2, 3, 

4). The label accompanying lot 1 bears the following 

note: "Probably the original of plate 11, figure Ib; 

certainly the original of plate 11, figure la, explicitly 

mentioned by Roemer." The smaller cranidium is 

practically complete, and its measurements agree very 

well with those of the original illustration. Inasmuch 

as Roemer based his genus and species on the cranidium, 

these cranidia should be considered syntypes, and the 

associated pygidia may be considered paratypes. 

According to Roemer's statement there should be four 

cranidia, hence four syntypes, but there were only 

two heads in the material received from Bonn.

The most obvious differences between the original 

specimens and the figures are the conspicuous eye 

lines, which are neither illustrated nor mentioned in 

the descriptions. These lines rise opposite the anterior 

pair of glabellar furrows and are directed outward and 

slightly backward, terminating at the anterior ends 

of the palpebral lobes. They are a conspicuous feature

so Etymol.: irrep&v, a wing; M<pa\fi, a head.
248 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

of all specimens that have been examined and are also 

present in other species referred to this genus.

In the original figure the glabella and brim are drawn 

slightly wider than they are in the specimen, and the 

facial suture is too sharply indented at the anterior end 

of the fixed cheek. Both of the type cranidia are more 

or less imperfect at this point, but the course of the 

suture is well shown on other specimens in the collections of the United States National Museum. The 

remaining important difference is that the posterior 

lateral lobes of the fixed cheeks are about 1.5 millimeters longer than the figure indicates.

At first sight the four fragmentary pygidia appear 

to belong to two or three distinct species, but on closer 

study the differences are found to be due chiefly to 

conditions of preservation and are therefore more 

apparent than real. The two large specimens are 

evidently adult forms, and the smaller ones probably 

represent immature individuals. The label accompanying the large specimen (no. 3), shown on plate 68, 

figure 8, bears the following note: "Designated by 

Roemer as the original of figure Ic." On the label 

accompanying the other large specimen (no. 2), plate 

68, figure 9, is written, "Probably the original of plate 

11, figure Id." Neither specimen, however, conforms 

exactly to the illustrations.

The dimensions of the type specimens are included 

in the table facing page 248.

A single fragmentary pleural segment included in 

the type material marked "San Saba * * * 10" 

may be the specimen mentioned by Roemer, but it 

differs in several particulars. It is about 23 millimeters long and 8 millimeters wide. Neither end is 

preserved, but the direction and curvature of the 

furrow indicate that it came from the right side of an 

individual. There is no way of telling whether this 

is the specimen mentioned by Roemer or not, as it 

was not figured, but its general size and shape seem 

to preclude it from belonging to Pterocephalia.

NOTES ON ADDITIONAL MATERIAL REFERRED TO THIS SPECIES

About 36 cranidia, all more or less fragmentary, 

have been compared with the types, and detailed 

measurements of most of these are plotted in the table 

facing page 248. The table also shows measurements 

of several pygidia, but these are much less abundant 

in the collections available. By this means it has 

been possible to compare specimens of all sizes from 11 

localities in Texas, Oklahoma, Missouri, South Dakota, 

and Nevada with the types. The most striking result 

of these measurements is the very close agreement of 

the proportions of each specimen regardless of size or of 

geographic source. For example, if the ratio of the 

length of the cephalon to the length of the glabella 

in the type specimen is compared with this ratio in the 

other specimens, it will be found that the differences

between them are so slight as to be well within the 

probable error of measurement, and also within the 

limits of individual variation.31 Comparisons of the 

ratio of other combinations of measurements on the 

type with the ratio of the same combinations on other 

specimens give equally close results.

Comparisons may also be made by establishing the 

ratio of a certain measurement on the type to the same 

measurement on the specimen to be compared, and 

then comparing this ratio with the ratio of other 

measurements on the same pair of specimens.

This very close agreement of relative proportions, 

regardless of size or geographic source (see table), 

is one of the Strongest reasons for considering all these 

forms to be a single species.

The pygidia from the Black Hills average somewhat 

wider than those from other localities but agree in 

all other respects. As they are preserved in a shale 

and are considerably flattened, whereas all the other 

specimens are preserved uncrushed in limestone, this 

extra width is interpreted as a result of the flattening, 

which, from the original shape of the pygidium, should 

be more transversely than longitudinally.

COMPARISON WITH OTHER SPECIES NOW REFERRED TO 

PTEROCEPHALIA SANCTISABAE

1. An examination of the type material of Pterocephalia laticeps (Hall and Whitfield) leaves no doubt 

that it is synonymous with P. sanctisabae Roemer. 

The species was described from the lowest limestones 

on Pogonip Mountain, White Pine district, Nev., 

now known to be of Upper Cambrian age. The 

cranidium as illustrated differs from P. sanctisabae 

in its narrower, more elongate, and somewhat angular 

glabella. The specimen from which Hall and Whitfield's illustration (pi. 68, fig. 40) was made shows all 

these characters, but not as strongly as the illustration 

would indicate. Associated with the type cranidium is 

the mold of a second cranidium which has almost 

exactly the size and proportions of the larger of 

the two type cranidia of P. sanctisabae. (See table, 

columns 2 and 32.) A clay squeeze taken from this 

second Nevada specimen and subjected to slight lateral 

compression developed the same peculiar combination 

of features which characterizes the figured cranidium 

of P. laticeps, and this, together with the fact that the 

rock in which this specimen is preserved shows traces 

of compression, indicates that P. laticeps was founded 

on a distorted specimen (pi. 68, figs. 40-42). An additional bit of evidence that favors this interpretation is 

found in a small collection from the Secret Canyon

31 These comparisons are most easily made by setting the two measurements which 

are to serve as the basis of comparison opposite each other on a slide rule and noting 

the difference between the proportional and actual measured dimension of the 

corresponding measurements on other specimens. In making these comparisons, 

naturally the more accurate of the two measurements to be compared should govern. 

In the table doubtful and obviously incomplete measurements are indicated by a 

query (?), and the figure given is usuall y less than what it should be.
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 249

shale south of the Hamburg mine, near Eureka, Nev. 

This collection contains six fragmentary cranidia, all 

of which have been identified as P. laticeps but which 

actually resemble P. sanctisabae far more closely. 

(See table, columns 34-36.) This relationship of P. 

sanctisabae and P. laticeps is easily demonstrated by 

comparing the cranidia of the types of these forms 

by the method outlined above. When the ratio of 

two measurements of length or of width on the type 

is compared with the same ratio based on measurements of P. laticeps, the agreement is found to be 

remarkably close.

For example, if the ratio of length of cranidium to 

length of glabella of the type of P. sanctisabae (24:10) 

is taken as the standard of comparison, it will be found 

that a cranidium 30 millimeters long should have a 

glabella 12.5 millimeters long, whereas the glabella of 

P. laticeps has a length of 12.25 millimeters. This is a 

discrepancy of only 2 percent, and it can certainly be 

charged to individual variation, or to error in measurement, or to both.

Similarly, if the ratio of width of cranidium to width 

of glabella of the type is taken as a standard (22:8.5), 

a cranidium which is 21 millimeters wide should have 

a glabella which is 8.1 millimeters wide. These last 

two measurements are those of the type of P. laticeps 

and show practically no discrepancy.

However, if the ratio of length of cranidium to width 

of cranidium (24:22) is taken as the standard, a cranidium 30 millimeters long should be 27.5 millimeters 

wide, whereas the cranidium of P. laticeps is only 21 

millimeters wide. This is a discrepancy of nearly 24 

percent, and the difference between the two measurements (6.5 millimeters) furnishes a measure of the 

amount of compression which the specimen has undergone.

The pygidium assigned to P. laticeps is figured as 

having a strong notch at the center of the posterior 

margin, whereas that of P. sanctisabae has only a 

shallow emargination at this point, but an examination of the specimen from which the figure of P. 

laticeps was drawn strongly suggests that this notch 

is due to a fracture of the posterior margin. No other 

pygidium assigned to P. laticeps preserves this margin, 

and the point cannot be settled at this time. The 

measurements of the pygidium of P. laticeps indicate 

that it has the same proportions as the pygidia of P. 

sanctisabae. (See table, columns 1, 2, and 31.)

2. Dicellocephalus multicinctiis Hall and Whitfield,32 

later referred by Walcott 33 without discussion to 

Apatokephalus, appears to have been founded on a 

fragmentary pygidium of Pterocephalia sanctisabae 

which lacks the entire posterior margin. The specimen is so broken that it gives a slight suggestion of

32 U. S. Geol. Expl. 40th Par. Kept., vol. 4, p. 226, pi. 2, fig. 37, 1877,

33 Walcott, C. D., Smithsonian Misp. Coll., vol. 57, p. 352, 1914,

possessing five blunt spines, which were accepted as 

real by Hall and Whitfield and were sketched in on the 

original figure, though regarding this feature the 

authors themselves were none too certain. A careful 

examination of the specimen shows that this suggestion of spines is entirely accidental, the part of the 

margin which is indicated as being preserved being 

the result of a fracture that probably healed during 

the life of the animal (pi. 68, fig. 37). In all other 

respects the specimen agrees perfectly with other 

pygidia of P. sanctisabae. (See table, column 32.)

DISTRIBUTION

Roemer's specimens were collected on the north bank 

of the San Saba River about half a mile east of Camp 

San Saba. (See p. 242.) An examination of the collections in the United States National Museum shows 

that the species is represented in collections from the 

Wilberns formation of Texas, the Honey Creek formation of the Wichita and Arbuckle Mountains, the Davis 

formation of the Ozark region, the Deadwood formation in the Black Hills, and the Secret Canyon shale of 

the Eureka district, Nev. It was also collected on 

Pogonip Mountain, in the White Pine district, Nev., 

from beds whose exact age is not known, but from the 

very narrow vertical range of the species elsewhere it 

would seem safe to refer these strata to the Secret 

Canyon. In every geographic province in which it 

has been found and at almost every locality within 

these provinces the species is associated with Elvinia 

roemeri (Shumard), and at most places with species of 

the genus Camaraspis.

In Texas the Camaraspis zone occurs in the Wilberns 

formation about 0 to 50 feet above the heavy sandstone 

which Paige mapped as the top of the Cap Mountain 

(Lion Mountain sandstone member). In the Wichita 

Mountains it is about 135 feet above the top of the 

Reagan sandstone at one locality, but in the West 

Timbered Hills of the Arbuckle Mountains it is about 

100 feet above the Reagan sandstone, according to 

measurements by C. E. Decker. In the St. Frangois 

Mountains of Missouri the zone is about 10 to 15 feet 

thick and occurs in the Davis formation about 20 to 

25 feet above the top of the Bonneterre dolomite. The 

exact position of the zone in the Secret Canyon shale 

of Nevada is not known at present.

In the Black Hills of South Dakota Pterocephalia 

sanctisabae, associated with Elvinia roemeri and other 

characteristic forms, has been found in a greenish-gray 

shale about 175 feet above the base of the Deadwood 

formation in Whitewood Canyon in the northern part 

of the town of Deadwood. These specimens were 

collected by Ed Barragy, of the University of Iowa, 

and have been made available for comparison by 

Dr. A. K. Miller, of that institution. In Wisconsin the 

Camaraspis zone occurs in the Ironton member of 

Franconia formation. Elvinia is fairly common jn this
250 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

zone, but Pterocephalia is extremely rare, although it 

has recently been found at one or two localities by 

Raasch.34

COMPARISON WITH OTHER SPECIES ASSIGNED TO PTEROCEPHALIA

Pterocephalia occidens Walcott 35 appears to be a valid 

species. All the known specimens came from a single 

locality south of the Hamburg mine, in the Eureka 

district, Nev. The formation is probably the Secret 

Canyon shale, although the original description states 

that they came from the "Hamburg" (Dunderberg) 

shale. The type cranidium is very small, being only 

6.5 millimeters long. The largest approximately complete cranidium in the collection is 17 millimeters long, 

and other fragments indicate a maximum length of 

20 millimeters. From this it would seem that the 

species is somewhat smaller in average size than Pterocephalia sanctisabae. The two anterior pairs of glabellar 

furrows are wanting or very faintly developed in P. 

occidens, and the last three segments of the pygidium 

are much fainter.

Pterocephalia asiatica Waleott 36 is a valid species. 

The type is fragmentary, but enough of the cranidium 

is preserved to show the essential generic characters. 

In most respects it is very similar to P. sanctisabae. 

The associated pygidium is too fragmentary for exact 

determination and probably does not belong to the 

same genus.

Dicellocephalus (Pterocephalia) bilobatus Hall and 

Whitfield,37 afterward referred by Walcott to Platycolpus 38 and still later to Anomocare,39 does not appear 

to belong to Pterocephalia but on the contrary seems 

best referred to some division of the Saukinae. The 

species is founded on a pygidium with a deeply cleft 

posterior margin which at first sight somewhat resembles Pterocephalia. However, the axis contains but 

6 segments, as against 10 to 11 in Pterocephalia. In 

addition, the marginal expansions are proportionately 

narrower, and the pleural furrows extend almost to the 

margin.

Pterocephalia busiris Walcott, described in the same 

reports as the preceding species,, is based on two pygidia 

that show none of the essential characters of Pterocephalia. It is a well-marked form and has been doubtfully assigned to Lioparia by Kobayashi. 40

Pterocephalia? liches Walcott, the third Chinese 

species, is likewise not a member of the genus and has 

been made the type of the new genus Kolpura by 

Resser and Endo.41

34 Raasch, G. O., personal communication, 1935.

as Walcott, C. D., Paleontology of the Eureka district: U. S. Geol. Survey Mon. 8, 

p. 58, pi. 9, fig. 21, 1884.

se Walcott, C. D., U. S. Nat. Mus. Proc., vol. 39, p. 67, 1905; Research in China: 

Carnegie Inst. Washington Pub. 54, vol. 3, p. 146, pi. 14, figs. 5, 5a, 5b, 1913.

s> U. S. Geol. Expl. 40th Par. Kept., vol. 4, p. 227, pi. 2, fig. 37, 1877.

3 8 Walcott, C. D., Smithsonian Misc. Col., vol. 57, p. 349,1914.

3» Idem, p. 366.

40 Kobayashi, T., The Cambro-Ordovician formations and faunas of south Chosen: 

Tokyo Imp. Univ., Fac. Sci., Jour., sec. 2, vol. 4, pt. 2, p. 231,1935.

41 Resser, C. E., and Endo, R., in £obayashi, T., op. cit., pp. 90, 23}.

As a result of these comparisons it appears that the 

genus as now known contains three species—namely, 

Pterocephalia sanctisabae Roemer, the genotype, which 

is widely distributed in the basal Wilberns and its 

equivalents in the Upper Cambrian of the Central and 

Western United States; P. occidens (Walcott), associated with P. sanctisabae in the Eureka district; and 

P. asiatica Walcott, from the Upper Cambrian of the 

Shantung district of China.

SYSTEMIC POSITION

.Roemer stated that Pterocephalia differed from all 

known genera of trilobites in certain particulars but 

made no attempt to show its relationships. Shumard 42 

considered it "to be related, if not identical with 

Conocephalites of Zenker," but did not discuss it further. 

Hall and Whitfield 43 made it a subgenus of Conocephalites without discussion. Walcott 44 at first considered it to be a subgenus of Ptychoparia, but in his 

later papers he gave it full generic rank. He never 

described the genus nor discussed its affinities. It was 

listed and described in Miller's "North American 

geology and paleontology" but is not mentioned in the 

English editions of Zittel's textbook nor in Grabau and 

Shimer's "North American index fossils."

Ulrich 45 listed the genus from Missouri, and Ulrich 

and Resser 46 mentioned it in a discussion of the genetic 

relationships of the dikelocephalids. In their paper 

they suggested that Pterocephalia should be placed in 

Raymond's subfamily Hungaiinae, but at the same 

time they removed this group from the Dikelocephalidae 

and suggested that it represents a distinct family 

which might also include Walcott's genera Burnetia 

and Elkia. This assignment was doubtless suggested 

by the broadly expanded margins of the cephalon and 

pygidium, but to the writer it seems more probable 

that this is a case of homeomorphy, and that the 

similarity is more apparent than real. Nor does 

Pterocephalia seem to be closely related either to 

Hungaia or to Burnetia, or Elkia.

In none of these forms is the expansion of the brim at 

all comparable with that of Pterocephalia. In the 

Dikelocephalinae and presumably in Burnetia and 

Elkia also the facial suture remains on the dorsal surface 

in crossing the median line, whereas in Pterocephalia it 

becomes marginal or submarginal directly in front of 

the eyes. The eye lines, which are conspicuous in

42 Shumard, B. F., The Primordial zone of Texas, with descriptions of new fossils: 

Am. Jour. Sci., 2d ser., vol. 32, p. 214,1861.

« Hall, James, and Whitfield, R. P., U. S. Geol. Expl. 40th Par. Rept., vol. 4, 

pp. 221-223, 1877.

44 Walcott, C. D., Paleontology of the Eureka district: U. S. Geol. Survey Mon. 8, 

pp. 58, 59, 1884; Cambrian faunas of China: U. S. Nat. Mus. Proc., vol. 29, no. 1415, 

pp. 67-68, 1905; Cambrian faunas of China: Smithsonian Misc. Coll., vol. 57, no. 4, 

p. 80,1911; Research in China: Carnegie Inst. Washington Pub. 54, vol. 3, pp. 146,147, 

1913.

« Ulrich, E. O., in Weller, Stuart, and St. Glair, Stuart, The geology of Ste. Genevieve County, Mo.: Missouri Bur. Geology and Mines, 2d ser., vol. 22, p. 51,1928.

« Ulrich, E. O., and Resser, C. E., The Cambrian of the upper Mississippi Valley, 

pt. 1: Milwaukee Pub. MUS, Bull,, vol. 12, no. 1, pp. 12-15,1930.
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 251

Pterocephalia, are not developed in the other forms. 

The head is thus truly ptychoparian, differing from 

other genera in that family chiefly in the great development of the brim.

In Pterocephalia the axis of the pygidium contains 10 

or 11 segments, twice the number characteristic of the 

Dikelocephalidae and Hungaiidae. The pygidia of 

Burnetia and Elkia are not definitely known, and hence 

no comparisons are possible.

Kobayashi 47 places the genus in the family Ptychopariidae and proposes a new subfamily, the Pterocephaliinae, to contain Pterocephalia, Amecephalus, Amecephalina, and possibly Alokistocare and Coosia.

Elvinia roemeri (Shumard)

Plate 67, figures 2a, b, 3a, b; plate 69, figures 1-22

1849. Pygidium of a trilobite of unknown genus and species, 

Roemer, Texas, p. 422, Nr. 11.

1852. Pygidium of a generically undetermined trilobite, Roemer, 

Die Kreidebildungen von Texas, p. 94, pi. 11, figs. 3a, b.

1852. Cephalon * * * of a trilobite belonging to an unknown genus, Roemer, Die Kreidebildungen von Texas, 

p. 93, pi. 11, figs. 2a, b (not 2c, d).

1861. Dikelocephalus roemeri Shumard, Am. Jour. Sci., 2d ser., 

vol. 32, pp. 220, 221.

1877. Crepicephalus (Loganellus) unisulcatus Hall and Whitfield, 

U. S. Geol. Expl. 40th Par. Rept., vol. 4, p. 216, pi. 2, 

fig. 22 (not fig. 23).

1884. Ptychoparia unisulcatus. Walcott, Paleontology of the 

Eureka district: U. S. Geol. Survey Mon. 8, p. 58.

1889. Dicellocephalus roemeri. Miller, North American geology and paleontology, p. 544.

1912. Ptychoparia matheri. Walcott, Smithsonian Misc. Coll., 

vol. 57, no. 9, p. 268, pi. 44, figs. 15-17.

1914. Ptychoparia roemeri. Walcott, Smithsonian Misc. Coll., 

vol. 57, no. 13, p. 352 (generic reference).

1924. Elvinia roemeri. Walcott, Smithsonian Misc. Coll., vol. 

75, no. 2, p. 56, pi. 11, fig. 3.

1925. Elvinia roemeri. Walcott, idem, no. 5, pp. 88, 89, pi. 17,

figs. 9-13. 

1928. Elvinia roemeri. Ulrich, in Wellerand St. Clair, Missouri

Bur. Geology and Mines, 2d ser., vol. 22, pi. 51 (cited in

faunal list). 

1981. Elvinia roemeri. Dake, Missouri Bur. Geology and

Mines, 2d ser., vol. 23, p. 88 (cited in faunal list). 

1933. Elvinia roemeri. Bridge, in Sellards, Adkins, and Plummer, Texas Univ. Bull. 3232, p. 232, pi. 2, figs. 17-19.

ORIGINAL DESCRIPTIONS

11- Pygidium of a trilobite of unknown genus and species. 

This is recognized by its very strongly elevated, half-cylindrical 

axis, which distinguishes it from other [known] trilobites.— 

Texas, p. 422.

12. Pygidium of a generically undetermined trilobite. Plate 

11, figs. 3a, b. (See F. Roemer, Texas, p. 422, no. 11.)

This pygidium is almost semicircular, arched, bordered by an 

upturned rim. The axis is thick and broad and is raised in the 

form of a hemicylinder high above the lateral sides of the shield. 

The width and height remain the same to the posterior margin of 

the shield, where it is abruptly truncated. The axis, aside from 

the anterior bordering ring, shows four annulations, the last one

" Kobayashi, T., op. cit., pp. 230, 231.

of which is more or les£ divided into two parts by a depression. 

Only the three anterior rings continue on to the strongly arched 

sides as broad, flattened pleurae.

The outstanding character of this pygidium is the thick axis, 

which maintains the same width throughout its length. The 

flattened, short pleurae indicate affinities with certain trilobite 

genera such as Ceraurus Green (Cheirurus Beyrich) and particularly Sphaerexochus Beyrich. However, in these last-named 

genera the outer margin is serrate, while in this specimen it is 

entire and plainly rounded.

Occurrence: Several complete examples of this pygidium, one 

of the largest of which is figured, were found in association with 

the other trilobites in the Silurian limestone in the San Saba 

Valley.

Description of the figures: Figure 3a, from above; figure 3b, 

profile view.

Besides the trilobites which have been described, the same 

rock contains three or four other forms, but the specimens before 

me are so incomplete that it is impossible to describe them 

adequately.—Kreidebildungen, p. 94.

11. Cephalon * * * of a trilobite belonging to an unknown genus. Plate 11, figures 2a, b.48

The material pertaining to this trilobite which is now before 

me shows clearly that it belongs to a distinct genus, but it is not 

sufficient to allow me to determine all of its generic characters.

The cephalon is elevated, semicircular in section, the anterior 

end with a broad, abruptly deflected border. The posterior end 

is bordered by an occipital ring which is set off by a well-marked 

occipital furrow. The glabella is bounded on all sides by a 

distinct furrow and rises to the same height as the fixed cheeks. 

It shows two faint, slanting glabellar furrows on each side. 

The course of the facial suture—in other words, the lateral 

edges of the cranidium—is not as plainly shown in the examples 

before me as in the illustration. However, one can readily see 

that in general it agrees with the facial suture in the genus 

Calymene in that the two lines are widely separated from each 

other at the anterior end and run in an oblique direction to the 

posterior corners of the cephalon. The free cheeks are missing 

in all known specimens. * * * No thoracic segments which 

might belong to this cranidium and pygidium are known. The 

relationship of the parts which have been described to other 

trilobite genera is not clear. The cephalon, on the one hand, 

shows a few similarities in structure with Calymene, but the 

pygidium, on the other hand, shows an entirely different type 

of structure.

Occurrence: Associated with the preceding [P. sanctisabae] in 

the crystalline Silurian limestone of the Sari Sab'a Valley.

Explanation of figures: Figure 2a, view of cephalon from 

above: 2b, the same in profile * * *.—Kreidebildungen, 

pp. 93, 94.

From the foregoing descriptions it will be seen that 

Roemer did not suggest any relationship between the 

cranidium and pygidium which are here classed as a 

single species. On the contrary, he considered a fragmentary cranidium of Idahoia to be a pygidium and 

associated it "very doubtfully" with the cranidium.

In 1861 Shumard published descriptions of several 

Cambrian species from the Central Mineral Region, 

among them Dikelocephalus roemeri. In his description 

of this species he says: "An excellent figure of this 

head is given by Dr. Roemer in his 'Kreidebildungen 

von Texas' (Taf. XI, fig. 2a), but the author proposes

48 The portions of the description which are omitted refer to another specimen which 

Roemer assumed to be the pygidium of this species but which is actually a fragmentary cranidium referred to Idahoia. (See p. 256.)—J. B.
252 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

no name for the species." Inasmuch as Shumard's 

specimens were never figured, and as his types appear 

to be lost, the specimen upon which Roemer's figure 

was based and which Shumard explicitly referred to 

his species is the nearest thing to a type that exists. 

In one sense, it might be considered a paratype, as it 

is a specimen mentioned in addition to the types in 

the original description, even though the author had 

only the figure available for comparison.

Shumard described a pygidium which he thought 

belonged to this species and also noted that the socalled pygidium which Roemer had assigned to it was 

actually the head of another form and referred it to 

Arionellus.

In 1924 Walcott 49 established the genus Elvinia, with 

Dikelocephalus roemeri as the genotype. The description was very brief, and the following year he published 

a second and somewhat more extended description.50 

In the second paper he stated that the pygidium assigned to Elvinia roemeri is not the same as the one 

described by Shumard, but he did not note that it is 

one of the unidentified forms described and figured by 

Roemer.

REVISED DESCRIPTION

Cranidium strongly convex, the length slightly more 

than half the greatest width; width of the frontal margin 

between the angles of the facial suture at the rim about 

half the width across the posterior lateral lobes; the 

angle between the axial plane and a line passing through 

the extremities of the rim and the posterior lateral lobes 

about 30°.

Glabella cuneiform, the sides converging anteriorly 

at an angle of 30°; abruptly truncated anteriorly, 

moderately elongated; sharply set off from the remainder of the cranidium by a strong circumglabellar 

furrow and slightly elevated above it. Width of the 

glabella at the posterior end approximately one-third 

the total width, and its length about seven-tenths that 

of the cranidium.

The anterior pair of glabellar furrows are extremely 

faint and cannot be detected on most specimens, 

especially those which preserve the test. They originate about opposite the eye lines and are directed 

posteriorly at an angle of 30°; second pair also faint but 

much more commonly observable, directed posteriorly 

at an angle of about 45°; third pair (first pair in Walcott's description) strongly defined, directed posteriorly 

at the same angle as the preceding pair for about onethird the width of the glabella, their inner ends connected by a strong transverse furrow. The course of 

this furrow is the distinguishing generic character cited 

by Walcott in his original description of Elvinia.

*< Walcott, C. D., Smithsonian Misc. Coll., vol. 75, no. 2, p. 56, pi. 11, fig. 3, 1921. 

5° Idem, no. 3, p. 88, pi. 17, figs. 9-13, 1925.

Occipital furrow rather strongly defined, narrowest 

along the axial plane and becoming wider and shallower 

toward the margins of the glabella.

Frontal border broad, convex, and abruptly deflected; divided into two very unequal portions by the 

marginal furrow; the width of the brim approximately 

three times that of the rim. Rim prominent, narrow, 

strongly rounded, broadly triangular.

Fixed cheeks rather narrow, about two-thirds the 

width of the glabella, and only slightly broadened at the 

palpebral lobes, which are not noticeably elevated 

above the surface of the cheek. Posterior lateral lobes 

broad and long, curved strongly downward, the extremities bluntly rounded.

Eye lines prominent, directed posteriorly at an angle 

of about 10°.

Facial suture cutting the frontal margin in front of 

the anterior corners of the glabella and extending 

laterally across the rim until it reaches a position in 

front of the posterior end of the palpebral lobe, thus 

giving the portion of the rim that is attached to the 

cranidium its triangular outline. In crossing the 

marginal furrow the facial suture bends abruptly 

inward to the anterior end of the palpebral lobe, curves 

gently around it, and then swings off at an angle of 

about 35°, cutting the posterior margin a short distance 

inside the genal angle.

None of the cranidia in the collections of the United 

States National Museum have the free cheeks attached. 

However, the cheek described here is associated with 

the cranidia at almost every locality from which the 

species has been collected, and it is the only one in the 

collections that can be logically assigned to this form. 

The outline is approximately that of a quarter ellipse, 

with the width slightly greater than the height. 

Marginal furrow strong and well defined anteriorly, 

becoming shallower and fainter as it approaches the 

genal angle. Occipital furrow broad and shallow. 

Rim strong and smoothly rounded, the anterior end 

produced into a spine by the course of the facial suture 

across it. Genal angle carrying a short, slender spine, 

which is directed outward at an angle of about 35° 

from the axial line. Surface of the cheek smoothly 

rounded.

Eyes not well preserved on any of the material at 

hand. They are about one-third the length of the 

cheek, crescentic, narrow, and not strongly elevated.

Doublure, hypostoma, and thoracic segments unknown.

Pygidium semicircular, about twice as wide as long. 

Anterior margins curving slightly back from the axis, 

strongly rounded at the outer angles. Posterior and 

lateral margins forming a semicircle, the edge rather 

strongly upturned, thickened, and rounded as if it were 

rolled about a wire. In many specimens this upturned 

margin is broken away, and the pygidium assumes
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 253

a triangular shape which at first sight causes it to be 

regarded as a distinct form.

Axis stout, about one-third the width of the pygidium, its sides parallel, strongly elevated, extending 

nearly to the posterior margin, the posterior end blunt, 

rounded, and standing high above the rim. Annulations four, not including the articulating ring, the 

terminal one double.

Lateral slopes moderately convex, becoming concave 

near the posterior and lateral margins. Each slope 

with three rounded pleural ridges, one opposite each 

of the three anterior annulations of the axis; the ridges 

separated by broad, shallow grooves.

Surface of the entire test smooth.

NOTES ON KOEMEK'S SPECIMENS

Roemer's material contains two cranidia and two 

pygidia referable to this species. There is also a third 

cranidium in the type lot, but it belongs to a different 

genus. (See p. 255.) The cranidia are numbered 6 and 

7, the pygidia 9 and 10. The labels accompanying the 

cranidia bear the following inscription: "Trilobite 

genus? caput. F. Roemer, Kr. v. Texas, Taf. XI, 

fig. 2a. Silurian, San Saba, Texas." On the back of 

the label of no. 6 is the following note: "On the back 

of the board to which this specimen was fastened is a 

note by Roemer stating definitely that this is the original (of fig. 2a)." On the back of the specimen itself 

is a notation in ink "I, 2, a." The "I" is very close to 

the margin and is evidently a portion of the Roman 

numeral XI. The other cranidium has no supplementary notes on either the label or the specimen.

The two cranidia are of medium size. Both specimens lack the outer half of the brim and the extremities 

of the posterolateral lobes. The occipital and posterior 

glabellar furrows are clearly defined; the anterior pair 

shows faintly in specimen no. 6. The eye lines are also 

indicated faintly in this specimen; in the other the 

surface of the test is flaked off at this point. The 

outlines of the glabella and fixed cheeks agree fairly 

well with the illustration, but the brim was evidently 

added from the third cranidium, which, as has already 

been noted, belongs to a different genus.

The two pygidia show a considerable variation in size, 

one being at least a third larger than the other. In both, 

the posterior and lateral margins are more or less 

incomplete. Both are referred to the same species. 

They conform to the descriptions, and no additional 

notes are necessary.

The label attached to the larger of the two specimens 

(no. 9) bears the following notation: "Trilobite genus? 

pygidium, F. Roemer, Kr. v. Texas, PL XI, figs. 3a, b, 

San Saba, Texas, Silurian." On the reverse is the 

following statement: "Definitely designated by Roemer 

as the original." The label accompanying the smaller 

specimen (no. 10) has practically the same notation on 

its face and the following on the reverse side: "Has

79717—37———3

probably served to supplement fig. 3a." Roemer's 

figures 2a and 2b give a fair idea of the cranidium but 

are incorrect in many of the details. The facial suture 

is incorrectly drawn, the eye lobes are too small and too 

prominent, the posterior lateral lobes are too short, 

and the rim is too thin and too sharply curved. His 

illustrations of the pygidium, figures 3a and 3b, are 

much better.

NOTES ON OTHER TYPES

Walcott's type cranidium (plesiotype) selected "as 

most nearly representing Shumard's description of the 

species" is about one-fourth larger than Roemer's 

specimens and is much more nearly complete. At first 

sight, Walcott's specimen appears to be sufficiently 

different to be regarded as another species. It appears 

to be flatter and to have a less abruptly deflected brim, 

but a comparison of the profiles shows that this is 

largely an optical illusion caused by the lack of part of 

the brim and all of the rim in Roemer's specimens. 

Such minor differences as do exist, such as the slight 

flattening of the cranidium, are those which are conceivably due to age. The greater part of the cranidium 

is exfoliated, traces of the skin remaining at the corners 

of the brim and along the posterior margin. The deep 

notch in the brim is due to an injury that healed during 

the life of the animal, for the chitinous skin is rolled 

around the edges of the fracture.

The pygidium figured by Walcott is identical in size 

and proportions with the larger of Roemer's specimens, 

and it shows the details of the upturned rim better 

than either of them.

The cranidium of Crepicephalus unisulcatus Hall and 

Whitfield is unquestionably an Elvinia, but the associated pygidium belongs to a different genus.

The type lot, the figured cranidium and pygidium 

on a fragment of limestone (U. S. Nat. Mus. 24574), 

came from the Eureka district, Nev., exact horizon 

and locality unknown. Associated with this specimen 

are two other lots from limestones in the Secret Canyon 

shale, Eureka district (localities 61 and 63), bearing 

the same number (24574) but collected at much later 

dates. Cranidia and free cheeks in these later collections were identified as C. unisulcatus by Walcott. 

Hall and Whitfield's original locality is very poorly 

described, and there is no way of determining whether 

either of Walcott's collections came from it, but there 

is a strong probability that all three collections came 

from the same horizon. The type cranidium is slightly 

smaller than Roemer's smaller specimen (no. 7). The 

margins of the fixed cheeks are broken away or buried 

in the matrix, and the posterior lateral lobes are missing, all of which tends to give the cranidium a narrow 

and more elongate appearance. The glabella appears 

to be squarer than the average, and the brim is more 

strongly arched and more sharply deflected. These 

characters seem to be peculiar to this specimen, _the
254 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

cranidia in other collections from the Eureka district 

agreeing more closely with the Middle Western types. 

The anterior pair of glabellar furrows are not preserved, and the second pair are very faint on the holotype but much more distinct on the paratype. Elvinia unisulcata has been considered to be a distinct 

species, but the type specimen is very poor, and 

most of the forms that have been referred to it agree 

better with E. roemeri. The writer considers E. unisulcata a synonym of E. roemeri.

Ptychoparia matheri Walcott is considered to be a 

synonym of Elvinia, roemeri. Ptychoparia, matheri was 

founded on several imperfect cranidia, a few free 

cheeks, and a single imperfect and very small pygidium from the top of the Potsdam sandstone near 

WMtehall, N. Y. The largest and most nearly complete cranidium, the one figured by Walcott and 

refigured on plate 69, figure 11, is slightly larger than 

Walcott's plesiotype of Elvinia roemeri. The relative 

proportions of the glabella and of such other parts of 

the two cranidia as may be compared are practically 

identical, with the exception of the width across the 

anterior end of the brim, which is relatively narrower 

in the New York specimen. The only other cranidium 

in this lot that is complete enough to permit this 

comparison to be made shows the same proportions as 

the Texas specimens, and this variation in width has 

been noted in collections from other localities. There is 

no fixed amount of variation, and the specimens cannot 

be divided into two sharply contrasted groups on this 

basis. In general, it may be said that the width 

across the brim is commonly slightly more than the 

length of the glabella, but it may narrow until it equals 

or is slightly less than this length. Moreover, this 

distinction does not appear to have either stratigraphic 

or geographic significance, and for these reasons it is 

not considered to be of specific importance. The free 

cheeks agree very well with cheeks from other localities. 

The pygidium is very small and very poorly preserved. 

It may not belong to the genus—in fact, according to 

Resser, it belongs to Dunderbergia. At one time the 

Potsdam sandstone was thought to be much younger 

than the beds carrying the Camaraspis fauna in the 

Mississippi Valley, but at present practically all stratigraphers agree that they are equivalent.

The genus Moosia, proposed by Walcott in the same 

paper with Elvinia, is now considered to be a synonym 

of it. 51 The genus was founded on a small lot of badly

51 Kesser, C. E., Nomenclature of some Cambrian trilobites: Smithsonian Misc. 

Coll., vol. 93, no. 5, p. 42,1935. Kobayashi, T., The Cambro-Ordovician formations 

and faunas of south Chosen: Tokyo Imp. Univ., Fac. Sci., Jour., sec. 2, vol. 4, pt. 2, 

p. 282, 1935.

crushed specimens from the Goodsir formation in 

British Columbia. Both cranidium and pygidium 

show the typical characters of Elvinia, and the writer 

agrees with Resser and Kobayashi in placing them in 

the same genus. The material now available is so 

scanty and so badly crushed that it is not possible to 

make detailed comparisons of the type species E. grandis with E. roemeri. There seem to be a number of 

rather striking differences, and for the present it is 

regarded as a distinct species. The lower few hundred 

feet of the Goodsir formation carry the typical Camaraspis fauna.

REMARKS

At first glance it would seem possible to divide the 

specimens here grouped under the name Elivnia roemeri 

into three or four species, and in fact this has been done, 

although some of them have never been published. 

Most of these species were described from a single 

locality, and in many of the descriptions the author 

did not have other material available for comparison. 

It is only within the last few years that enough specimens have been brought together to permit detailed 

studies to be made. In all, some 40 cranidia and a 

smaller number of free cheeks and pygidia have been 

used in making these comparisons. This material 

came from 18 localities scattered through the States of 

New York, Wisconsin, South Dakota, Missouri, Oklahoma, Texas, Utah, and Nevada.

The most striking result of this comparison is that 

while certain variations wiiich have been called species 

exist, they have neither geographic nor stratigraphic 

significance. For example, Elvinia roemeri, originally 

described from Texas, has been listed from Oklahoma, 

Missouri, Wisconsin, and South Dakota. "Elvinia 

unisulcata" (type locality Nevada) has been reported 

from Utah, South Dakota, Missouri, and Texas, and 

"E. matheri" (type locality New York) has also been 

identified in Wisconsin and Missouri.

In his second description of Elvinia roemeri Walcott 

states that "it will be necessary to make several species 

from among the numerous specimens from Texas," 

and this was done in the collections, although the distinctions were never published. Some of these forms 

had a similarly wide distribution. Actually, there is 

as much or more variation between the individuals 

assigned to one or another of these so-called species 

as there is between the types of the various forms, and 

many specimens cannot be placed satisfactorily in any 

one of them. (See table on p.^255.)
REDESCRIPTTON OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 255

Comparative measurements, in millimeters, of 12 cranidia of Elvinia roemeri

[Measurements followed by plus sign are incomplete because of fracturing. Width of brim is an unreliable measurement, partly because of individual variations and 

partly because corners are often deeply buried or lost. Large specimens are relatively less convex than smaller ones.J

Length of cranidium - ___

Width of cranidium at posterior lateral lobes

Length of brim ___ __ _ Width of brim . __ _

Width of glabella . . _ _ _ _ . _

Width of glabella at anterior 

end._ _ _ Width of fixed cheek at palWidth of cranidium at palHeight of cranidium _ _ _ _

Texas

Paratype A 

(pi. 69, 

fig. 1)

27 +

15 

13 

10. 5

6

4. 1

18 

4 

5.8? 30°

Paratype B 

(pi. 69, 

fig. 4)

25 +

11.5 

9

5

4

15. 5 

3 

5. 1? 30°

Plesiotype, 

locality 

70, 

U. S. 

N. M. 

70259 

(pi. 69, 

fig. 9)

25. 6

46 

7. 7 

22. 5 

17. 9 

15

7.5

7

26 

5 

10. 4 30°

Locality 68, 

U. S. N. M. 

93013 

(p!. 69, 

fig. 15)

16.6

24 + 

4.4 

12. 5 

12. 3 

10

5.2

4.3

17. 2 

3.7 

6 30°

New York

P. "matheri", 

holotype, U.S. 

N. M. 58585 

(pi. 69, fig. 11)

28 +

7 

22.5 + 

21 

17

8. 7 

8.5

31 

5.2 

12 30°30'

Nevada

E. "unisulcata", 

U. S. N. M. 24574

Holotype 

(pi. 69, 

fig. 17)

14

15 + 

3. 8 

11 

10.2 

8. 3

4. 7 

3. 5

14 

2. 6 

5. 8 29°

Ples:otype 

(pi. 69, 

fig. 18), 

locality 

63

16. 5

30 

4.2 

12. 4 

12.3

9.8

5 

5

18 

4. 2 

7 30°

Utah

Locality 

32-t, 

U.S. 

N. M. 

93026 

(pi. 69, 

fig. 32)

23

40 

7 

17.5 

16 

13.5

8 

6.6

123 

5 

11 30°

South Dakota

Locality 88-a. Deadwood

U.S. 

N. M. 

93024 

(pi. 69, 

fig. 16)

17

27. 6 

5 

12. 2 

12 

9.5

5. 1

4.8

16 

3. 5 

8. 5 30°

PI. 69, 

flg. 14

27.5

40 + 

8 

20.5 + 

19.5 

17.5

9

5 + 

9 + 30°30'

Missouri

Locality 

11-k, 

Flat 

River, 

U.S. 

N. M. 

93011 

(pl. 69, 

fig. 12)

23. 6

41 

7. 2 

19.5 

16. 4 

13.4

7.6

7

22.2 

5.5 

13 30°

Oklahoma

Locality 

89-v, 

West Timbered 

Hills, 

U.S. 

N. M. 

93025 

(pl. 69, 

fig. 19)

28 +

52

7.6 +

20. 4 

17

10 

7.3

28 

6.5 

9 30°

Presence or absence of test seriously affects certain measurements, especially width across palpebral lobes.

OCCURRENCE

Roemer's specimens were collected on the San Saba 

River at the same locality and from the same beds 

that yielded Pterocephalia. Shumard's specimens were 

collected at the head of Clear Creek, Burnet County. 

His statement that it is associated with Tricrepicephalus 

texanus is an error, for although the Tricrepicephalus 

horizon is present at this locality, it is at least 100 feet 

lower in the section. Walcott's specimens came from 

two localities in the Central Mineral Region. He 

gives the horizon as Cap Mountain, but later work has 

shown that the correct horizon is the basal part of the 

Wilberns formation. It has been found at several 

other localities in the Central Mineral Region and is 

invariably associated with Pterocephalia sanctisabae. 

The same association is found in the Honey Creek limestone in the Arbuckle and Wichita Mountains of 

Oklahoma, in the basal part of the Davis formation of 

Missouri, at a certain horizon in the Deadwood formation in the Black Hills, and in the Secret Canyon shale 

in the Eureka district of Nevada. It also occurs in 

the Ironton member of the Franconia formation in 

Wisconsin, where it is associated with Camaraspis, 

Idahoia, Irvingella, and other genera characteristic of 

the Wilberns, Honey Creek, and Davis. It occurs also 

in the top of the Potsdam sandstone in the Lake 

Champlain region, in beds in the Dugway Range in 

Utah which are presumably the equivalent of the upper 

portion of the Orr formation in the adjacent House 

Range, in Upper Cambrian limestones in the southwestern part of Sublette County, Wyo., and in limestones in the lower portion of the Pogonip limestone 

of the White Pine district of Nevada. It has a somewhat greater vertical range than P. sanctisabae, for 

it is also found sparingly in the Irvingella major zone, 

which immediately overlies the Camaraspis zone in 

many areas.

Specimens of Elvinia roemeri from the Ore Hill limestone of Pennsylvania agree in all respects with tjte 

forms just described and serve to correlate the Ore Hill 

with the lower Franconia. The species has recently 

been found in collections from southwestern Wyoming.

The species has been recognized in collections from 

about 19 localities in 9 widely separated States, and in 

almost every locality it is associated with other equally 

characteristic forms. This association over so broad 

an area is of great value in interregional correlation.

Aphelaspis depressa (Shumard)

Plate 69, figures 23-26

1861. Conocephalites depressus Shumard, Am. Jour. ScL, 2d

ser., vol. 32, pp. 219, 220. 

1889. Ptychoparia depressa. Miller, North American geology

and paleontology, p. 565. 

1935. Aphelaspis depressa. Resser, Smithsonian Misc. Coll.,

vol. 93, no. 5, p. 11.

Among the Roemer specimens is a small fragment of 

limestone (no. 5) which bears the same label as those 

accompanying the cranidia of Elvinia roemeri (nos. 6 

and 7). The label also carries the following notation: 

"Almost certainly used in filling out fig. 2c." The 

block contains several fragmentary cranidia, three of
256 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

which are fairly complete and all of which belong to 

the same species. The species is entirely different from 

E. roemeri and has been identified with one of 

Shumard's unfigured species, Conocephalites depressus. 

This species has recently been made the type of a new 

genus, Aphelaspis, by Resser, but it has never been 

figured. The best-preserved cranidium of Roemer's 

specimen is figured in plate 69, figures 23, 24. Other 

specimens from Texas selected by Walcott to replace 

Shumard's lost types are shown in plate 69, figures 

25, 26.

The original description is sufficient and need not be 

repeated.

OCCURRENCE

This species is extremely abundant in the upper part 

of the Cap Mountain formation, in limestones immediately below the Lion Mountain sandstone member, 

and in limestone lenses in the base of that member. It 

occupies a zone about 40 feet thick, which, owing to the 

abundance of this form, has come to be known as the 

Aphelaspis zone.

This zone does not occur on the San Saba River 

at the ford half a mile east of Camp San Saba, cr at 

any other point farther upstream. It is exposed on 

both sides of the river just west of Voca, and this 

particular specimen is believed to have come from that 

locality. The lithology is so very similar to that of 

the Camaraspis zone that they could easily be confused 

with one another.

Idahoia? sp. 

Plate 67, figures 2c, d; plate 69, figures 27. 28

1852. * * * 62 Pygidium of a trilobite belonging to an unknown 

genus, Roemer, Kreidebildungen, p. 93, pi. 11, figs. 2c-d.

.1861. Arionellus sp. Shumard, Am. Jour. Sci., 2d ser., vol. 32, 

p. 221.

OBIGINAL DESCRIPTION

The pygidium (figs. 2c, d) next to be described is very doubtfully associated with, this cephalon. It was not observed joined 

to the cephalon by means of the thorax, but only as separate 

parts. The reason for considering them to be related is the 

fact that they are associated together and that both show about 

the same degree of rounding [elevation]. The pygidium in 

question is strongly elevated, almost triangular, and terminates 

posteriorly in a small, somewhat posteriorly directed spine. 

In the middle of the pygidium is an oval, strongly and evenly 

elevated area surrounded on all sides by a furrow. The posterior portion of the furrow that outlines this area appears to 

continue along the lateral margins of the shield on both sides. 

However, it is not a plane, as the drawing would indicate. The 

anterior portion of the furrow separates the oval area from the 

forward portion of the shield, which is bowed upward in a cross 

roll [transversely], and this in turn is separated from the upturned anterior margin by a broad furrow. * * *

i3 Section omitted here is given in the description of Elvinia roemeri.

Occurrence: Associated with the preceding in the crystalline 

Silurian limestone in San Saba Valley.

Explanation of the figures: * * * 2c, view of the pygidium 

from above; 2d, view of the pygidium in profile.

REMARKS

Roemer's material consists of a small fragment of 

limestone (no. 8) containing an imperfect cranidium. 

Only the occipital ring, the glabella, and a portion of 

the brim, retaining parts of the test, are preserved. 

All of the margin, except that of the occipital ring, is 

missing, so that from the specimen it is very difficult 

to form any idea of the original outline. The glabella 

has parallel sides and is evenly rounded anteriorly. It 

is rather strongly elevated. The circumglabellar furrow is distinct and strongly impressed. No glabellar 

furrows can be detected, but the lack of them may be 

due to conditions of preservation. Occipital furrow 

strong; occipital ring broadly triangular; the apex to 

the rear and terminated by a strong, posteriorly directed occipital spine. The brim is about equally divided 

into a strongly deflected, preglabellar area and a flat 

or slightly upturned rim. The preglabellar area bears 

markings that resemble radial striations, but this may 

be due to weathering.

The accompanying label bears the following notation: "8) Trilobite genus? pygidium? F. Roemer, 

Texas, pi. 11, figs. 2c, d, Silurian, San Saba, Texas."

The general appearance of this specimen suggests 

that it should be placed in Walcott's genus Idahoia. 

The glabella of this specimen is more truly oval than 

in typical Idahoia. Moreover, Idahoia has never been 

found in beds as low as the Camaraspis zone but occurs 

somewhat higher in the section in the PtychaspisProsaukia zone.53

Roemer's specimen could also be referred to the 

genus Saratogia, a form which is closely allied to 

Idahoia and which future work may show to be congeneric with it. In Saratogia the glabella is more 

rectangular in outline and more abruptly truncated 

anteriorly, the glabellar furrows show more distinctly, 

and the preglabellar area and run are slightly different, 

but whether these differences are generic or specific is 

yet to be determined.

OCCURRENCE

The specimen is said to have been collected at the 

same locality that yielded the other trilobites. No 

other specimens referable to this form have been found 

in the collections from Texas, but an undescribed 

species believed to be identical with it occurs in the 

Ironton member of the Franconia formation in 

Wisconsin.

«' Raasch, G. O., Stratigraphy of the Cambrian system of fhs upper Mississippi 

Valley: Kansas Geol. Soc., Ninth Ann. Field Conference, Guidebook, p. 303,1935.
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC FROM 257

ORDOVICIAN SPECIES

By JOSIAH BRIDGE 

GASTROPODA

Ophileta polygyrata (Roemer)

Plate 67, figures 4a, b; plate 69, figures 29-34, 36, ?35

1849. Euomphalus polygyratus Roemer, Texas, p. 421.

1852. Euomphalus polygyratus Roemer, Die Kreidebildungen

von Texas, p. 91, pi. 11, figs. 4a, b. 

1889. Euomphalus polygyratus. Miller, North American geology

and paleontology, p. 404. 

1900. Pleurotomaria hunterensis Cleland, Bull. Am. Paleontology,

vol. 4, no. 18, pi. 16 (42), pi. 4, fig. 2 (not fig. 1). 

1903. Polygyrata polygyratus. Weller, New Jersey Geol. Survey,

Paleontology, vol. 3, Paleozoic faunas, p. 130. 

1903. Polygyrala sinistra Weller, idem, p. 130. 

1903. Polygyrata hunterensis. Weller, idem, p. 130. 

1915. Polygyrata hunterensis. Bassler, U. S. Nat. Mus. Bull. 92,

p. 1020.

1915. Polygyrata polygyrata. Bassler, idem, p. 1020. 

1915. Polygyrata sinistra. Bassler, idem, p. 1020. 

1919. Ophileta complanata Bassler, Maryland Geol. Survey,

Cambrian and Ordovician, p. 302, pi. 31, figs. 2-5.

1932. Ophileta polygyrata. Bridge, in Dake and Bridge, Geol. 

Soc. America Bull., vol. 43, p. 741, pi. 12, fig. 10 (type 

refigured).

1933. Ophileta polygyrata. Bridge, in Sellards, Adkins, and 

Plummer, Texas Univ. Bull. 3232, p. 233, pi. 3, fig. 10 

(type refigured).

ORIGINAL DESCRIPTIONS

8. Euomphalus polygyratus. n. sp. Shell l"3"f in diameter, 

convex, with numerous whorls, 9—10, narrow, subequal, oppressed, 

[the upper surface] of each one lying in the same plane and forming 

a low cone above.

This species resembles E. gualteriatus Goldfuss (Helicites 

gualteriatus Schlotheim) in that the upper surface of all the 

whorls forms a blunt conical surface, but it differs from this form 

in the much greater number of whorls [which it possesses].

A single specimen was found in gray (Silurian?) limestones 

about 20 English miles below the old Spanish fort.—Texas, 

p. 421.

7. Euomphalus polygyratus

Plate 11, figures 4a, b 

Euomphalus polygyratus F. Roemer, Texas, p. 421.

Diameter 1"3'", height 5'"

Shell coiled dextrally, convex above, bluntly conical, concave 

below; with numerous (9—10) narrow, almost equal, appressed 

whorls, the same forming a blunt, conical surface; with the section 

across the whorls subrhomboidal.

The shell is convex above, obtusely conical, concave below; 

whorls numerous (9-10), narrow, very slowly increasing in width, 

thus forming almost equal whorls which are pressed closely on 

one another with the upper surface in the same obtuse conical 

plane without interruption. The cross section of the whorl is 

almost rhomboidal.

This form is particularly distinguished by two characters—by 

the obtusely conical upper surface, which is formed by the edges 

of the whorls meeting without interruption, and by the significant 

number of the whorls. It has the first of these characters in 

common with Euomphalus gualteriatus Goldfuss (Helicites gualteriatus Schlotheim), from the Silurian strata of Sweden and 

Russia, which [species], on the other hand, differs from it in 

the much lower number of whorls (3-4) and in the much more 

rapid manner in which they enlarge.

Occurrence: The single specimen that serves as the basis of 

the preceding description is an internal mold found in a gray 

limestone in San Saba Valley about 20 miles below the site of 

the old Spanish fort. The relationship of this species with a 

Silurian form indicates that the limestone which contains it is 

itself a part of the Silurian system and probably of the older 

Silurian.

Description of figures: Figure 4a, view from above; figure 4b, 

apertural view.—Kreidebildungen, p. 91.

NOTES ON THE TYPE SPECIMEN

The holotype (no. 11) is an internal mold preserved 

in a fine-grained gray, slightly magnesian limestone. 

Only the dorsal surface is shown, the umbilicus being 

concealed by the matrix. The outer whorls are broken 

at several places, allowing good cross sections of the 

whorl to be obtained. The upper surface is deeply 

weathered, so that all surface markings are obliterated, 

and the whorls forming the summit of the spire are 

eroded away. Seven whorls may be definitely counted, 

and the extremely slow rate of increase in diameter of 

these indicates that there were at least four more in 

the spire. The ratio of increase is about 6:5.

What appears to be the aperture is shown in the 

upper right-hand corner as the specimen is figured. 

The small projections in the extreme upper and lower 

right-hand corners fail to show cross sections of the 

whorl and are considered to be matrix.

The whorl is rhomboidal in cross section, wider than 

high, the upper and lower outer slopes meeting the 

slightly supramedian peripheral keel at an angle of 

about 65°. The upper surface is so badly corroded 

that no traces of the sigmoid profile of the shoulder 

remain.

The dimensions of the fragment are, actual diameter 

31 millimeters, restored diameter 35 millimeters, actual 

height 12 millimeters, restored height 15 millimeters, 

diameter of umbilicus approximately 29 millimeters, 

height of body whorl near aperture 4 millimeters, 

width at same point 7.7 millimeters (estimated), 

apical angle 125°.

The shell agrees very closely in size and general 

proportions with the large syntype of Pleurotomaria 

hunterensis Cleland. (See table, p. 258.) The most 

noticeable difference is in the apical angle, which is 115° 

in Cleland's specimen 54 and between 120° and 125° 

in Weller's. The latter figure agrees almost exactly 

with the apical angle of the small, incomplete specimen 

shown in Cleland's figures 7 and 8.

COMPARISON WITH OTHER FORMS

The great similarity between Euomphalus polygyratus 

Roemer, Pleurotomaria hunterensis Cleland, and Polygyrata sinistra was originally pointed out by Weller,55 

who assigned all three forms to his genus Polygyrata

« Cleland, H. F., The Calciferous of the Mohawk Valley: Bull. Am. Paleontology, 

vol. 3, no. 13, p. 12 (124), pi. 17, figs. 7, 8, 1900.

i* Weller, Stuart, The Paleozoic faunas: New Jersey Geol. Survey, Paleontology, 

vol. 3, p. 130, 1903.
COiSlMufeuttONS fO GENERAL GEOLOGY, 1936

but retained them as distinct species. Later Ulrich 

and Bridge, 56 after comparing the types of the three 

species, concluded that Polygyrata sinistra Weller was 

a synonym of Ophileta hunterensis (Cleland). They 

also noted the great similarity between these forms and 

Roemer's specimen but provisionally considered them 

to be distinct. As P. sinistra was the type of Weller's 

genus, and Ophileta was the older name, Polygyrata was 

made a synonym of Ophileta. The restudy of Weller's 

type showed that he was mistaken in interpreting his 

species as a sinistrally coiled form. The growth lines, 

which are faintly preserved on the outer whorl (pi. 69, 

fig. 34), show plainly that the shell coiled to the right 

in the normal manner and not to the left as shown in 

Weller's figure.57

The basis of Weller's interpretation is to be seen in a 

small healed fracture, a minute scissors fault which has 

displaced the shell on each side of the break to the 

extent indicated by the depth of the whorls in his 

figure 2. At the same time, there was also a slight 

amount of lateral displacement, and it was this fact 

which caused him to interpret the shell as sinistral. 

The growth lines on the specimen (pi. 69, figs. 33, 34) 

show that this is not the case.

The differences between these New York and New 

Jersey forms and Roemer's specimen are very slight, 

the latter being slightly smaller, with slightly narrower 

whorls and a wider suture line. It is an internal mold, 

which preserves no traces of the outer shell. These are 

present in the other specimens, and this is believed to 

account for the difference, for the shell is invariably 

thickened along the peripheral keel, and this thickening 

broadens the whorls and narrows the suture line. In 

the autumn of 1934 the writer collected several specimens referable to this species at two localities in the 

western part of the Central Mineral Region. One of 

these was on the San Saba River in the general vicinity 

of the locality that furnished Roemer's specimen 

(p. 242), and the other was on Honey Creek southwest 

of Mason. Some of these specimens preserve the outer 

shell (pi. 69, fig. 36). The agreement between these 

forms and those from New York and New Jersey is so 

close that the writer regards them as conspecific, and 

as Ophileta polygyrata has many years' priority, 0. 

hunterensis (Cleland) (including Polygyrata sinistra 

Weller) is regarded as a synonym.

The measurements of the various specimens used in 

this comparison are given below:

88 Ulrich, E. O., and Bridge, Josiah, Ophileta, Polygyrata, and Lecanospira [abstract]: 

Qeol. Soc. America Bull., vol. 43, no. 1, p. 278, 1932. 

v Weller, Stuart, op. cit., pi. 4, fig. 1.

Measurements, in millimeters, of specimens of Ophileta

[An asterisk indicates that the measurement has been computed to allow for a portion 

of the specimen which is not preserved]

Diameter _______ ___

Altitude _ ____ _____ __

Diameter of umbilicus ___ ___

Width of body whorl near aperO. polygyrata 

holotype

*35 

*15 

125° 

29-

3. 2?

O. hunterensis 

holotype

38 

*19 

115° 

30?

4.4

O. hunterensis 

fragment

15 

5 115° 

5. 5

O. sinistra

36•j _

125° 

29?

4

OCCURRENCE

According to Roemer the holotype was collected in 

the San Saba Valley about 20 miles downstream from 

the old Spanish fort (Menard). This is all the information given in his description, but from a study of his 

narrative 58 it seems fairly certain that the specimen 

was collected on the return journey, and that it came 

from the south bank of the river about 5 miles below 

the point where the Paleozoic strata disappear beneath 

the Cretaceous rocks in the bed of the river. This 

locality is probably in Mason County somewhere near 

the Menard County line.

As noted above, the writer his collected Ophileta 

polygyrata at two localities. In both it occurs in association with Eccyliomphalus gyroceras (Roemer) in dense 

white limestone of Gasconade age that forms the base 

of the Ellenburger throughout most of the western part 

of the Central Mineral Region. This limestone is the 

one which Dake and Bridge 59 called the Eccyliomphalus 

gyroceras zone and which they considered to be the 

middle division of their Gasconade faunal equivalent. 

This is now known to have been an error, as recent work 

has shown conclusively that their so-called lower member of the Gasconade faunal equivalent is merely the 

down-faulted upper member. Thus the Gasconade 

faunal equivalent as now known consists of two members—a lower white limestone carrying Eccyliomphalus 

gyroceras and Ophileta polygyrata and an upper dolomitic 

zone carrying the more common Gasconade assemblage.

Eccyliomphalus gyroceras (Roemer)

Plate 67, figures 6a, b; plate 70, figures 6-10

1852. Euomphalus gyroceras. Roemer, Die Kreidebildungen von

Texas, p. 91, pi. 11, figs. 6a, b. 

1889. Eccyliomphalus gyroceras. Miller, North American geology

and paleontology, p. 403.

ss Roemer, F., Texas, p. 314, 1849.

M Dake, C. L., and Bridge, Josiah, Faunal correlation of the Ellenburger limestone 

of Texas: Qeol. Soc. America Bull., vol. 43, p. 735, fig. 2,1932.
REDE3CRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 259

1898. Phanerotinus gyroceras. Weller, U. S. Geol. Survey Bull.

153, p. 420. 

1915. Eccyliomphalus gyroceras. Bassler, U. S. Nat. Mus. Bull.

92, p. 467.

1932. Eccyliomphalus gyroceras. Bridge, in Dake and Bridge, 

Geol. Soc. America Bull., vol. 43, p. 740, pi. 12, fig. 6.

1933. Eccyliomphalus gyroceras. Bridge, in Seltards, Adkins, and 

Plummer, Texas Univ. Bull. 3232, p. 233, pi. 2, fig. 6.

ORIGINAL DESCRIPTION

9. Euomphalus gyroceras, n. sp.

Plate 11, figures 6a, b 

Diameter 1"1"'; height 2'"

Shell an incomplete spiral in one plane, with whorls completely 

separate, with less than two [whorls]. Cross section of the whorl a 

compressed oval. The shell is an incomplete spiral, coiled in the 

same plane, forming less than two complete volutions, often 

scarcely one, in which case it appears hook-shaped. The whorls 

free, separated by a wide interval. The cross section of the whorl 

is oval, somewhat compressed dorsoventrally.

This form is most closely related to those in the Devonian 

limestones at Paffrath am Rhein and in the Harz Valley. It 

also resembles Euomphalus serpuJa De Koninck (Serpularia 

centrifuga A. Roemer), which occurs in the Carboniferous limestone of Belgium and which also differs from the typical form 

of the genus in its free whorls, which do not touch each other. 

The Texas species, however, differs from the European forms in 

the compressed, oval cross section of the whorl, which is circular 

in Euomphalus serpula, and in the coiling of the whorls in the 

same plane, while the European forms for the most part are 

more or less plainly conically coiled. In addition, the number 

of whorls in the latter species is greater.

The generic designation of this form is doubtful, because all 

the Texas specimens agree in the wide separation and small 

number of the whorls—characters not attributed to the genus 

Euomphalus. A great number of Texas specimens were examined, and all agree in these particulars, so that it is plainly the 

normal habit of the species. Moreover, although a single specimen with free whorls is occasionally found in other gastropod 

genera that have the whorls in close contact—for example, 

Helix—the close-coiled condition is the normal one, while here 

the opposite is the case. In addition, the small number of volutions constitute a form which is very different from that of the 

true Euomphalus. In case more detailed studies should justify 

the removal of this and similar forms from this genus (Euomphalus'), it might be placed in the new genus Serpularia,60 which 

my brother, A. Roemer, has named.

Finally, it is to be noted that these shells, which for the most 

part are preserved as natural longitudinal sections, show no 

internal cross partitions or septa, similar to those possessed 

by many true species of Euomphalus.

Occurrence: Many specimens with partly preserved shells 

were collected from a compact bright yellowish-gray limestone 

(Carboniferous limestone?) occurring in the valley of the San 

Saba River about 20 English miles below the old Spanish fort.

Description of figures: Figure 6a, view from above; figure 6b, 

cross section of the last whorl.—Kreidebildungen, p. 91.

60 Name preoccupied by Serpularia Munster, 1840 (Vermes). Serpularia A. 

Roemer, 1843 (Mo\liisca)=Serpulospira Cossman, 1915, genotype Serpularia centrifuga 

A. Roemer, 1843, according to information furnished by J. B. Knight. The genotype 

is a Devonian form, but future work may show that many of the early Paleozoic 

American species now referred to Eccyliomphalus should be placed here.—J. B.

REMARKS

The type material consists of two specimens (nos. 13 

and 14), both of which are natural, longitudinal sections preserved in a limestone matrix. The original 

figure is evidently based on the specimen illustrated in 

plate 70, figure 6, and a note on the back of the label 

confirms this conclusion. The specimens must be 

considered syntypes.

Syntype A (the specimen just mentioned) shows a 

longitudinal section as seen from the ventral side (on 

the assumption that the direction of coiling is dextral) 

and consists of about 1% volutions. The inner end 

of the whorl tapers to a fine point, and there is no 

trace of a more closely coiled inner portion, but the 

lack of this is probably due to weathering. No section 

of the whorl is obtainable on this specimen. The 

ventral side appears to have been smoothly rounded, 

with the maximum convexity slightly toward the 

inside of the center The ventral side of the aperture 

seems to have been entire or very slightly sinuate.

Syntype B (pi. 70, fig. 7) also shows a natural longitudinal section, but in this specimen it is seen from the 

dorsal side. It is not as well preserved, only about 

one-half of the final whorl remaining, and it s quite 

evident that the inner whorls have been eroded away, 

for at one point there is a faint suggestion of one of 

them. The apertural end intersects the margin of 

the fragment of rock and affords a good cross section 

of the ventral half of the whorl, which agrees very well 

with the section postulated for syntype A.

Neither specimen shows any trace of surface markings or gives any clue to the profile of the dorsal side. 

In neither one is there any definite trace of the septa 

that are so noticeable in certain species of this genus, 

notably in Eccyliomphalus multiseptarius Cleland.

Examples of this species collected by C. L. Dake and 

the writer show additional characters not shown by 

the types. Several show the initial spiral, and these 

indicate that the shell consists of about 1% volutions 

and that the whorls are nowhere in contact. Other 

fragmentary specimens show that the whorl is oval in 

cross section, slightly flattened on the inner side, with 

the longer diameter parallel to the plane of coiling. 

None of the specimens observed show any trace of 

surface markings or of septa.

The dimensions of the types are, syntype A, diameter 

31 millimeters, width of whorl near aperture 8 millimeters, width of whorl one-half volution from aperture 3.5 millimeters; syntype B, slightly larger, diameter 36 millimeters, width of whorl near aperture 8.5 

millimeters, width of whorl one-half volution from 

aperture 5 millimeters.

Most of the specimens in the United States National 

Museum are somewhat smaller, but some of them attain 

the size of Roemer's specimens. The diameters of the
260 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

whorl of a large fragment are 7 and 8.5 millimeters; 

those of a smaller specimen are 5 and 6 millimeters.

OCCURRENCE

The types came from the locality on the San Saba 

River about 20 miles below the old Spanish fort which 

has already been discussed in connection with Ophileta 

polygyrata, and in 1934 the writer collected both species 

in this same general locality (p. 242). The matrix is a 

dense fine-grained creamy-white to yellowish, almost 

lithographic limestone which is known to occur at 

three horizons, at least, in the Ellenburger.

The limestone carrying E. gyroceras is the lowest of 

the three white limestones above noted. It is the basal 

portion of the Gasconade division of the Ellenburger. 

Several specimens were collected near the top of this 

zone along the Mason-Brady highway about 1.45 miles 

north of the bridge at Camp San Saba. In this section 

it is about 100 feet above limestone carrying an Upper 

Cambrian fauna.

The species has also been collected in the extreme 

southwestern part of the Llano uplift from outcrops 

along the White ranch road about 7 miles southwest of 

the bridge across the Llano River. At this locality 

these white limestones are the oldest rocks exposed and 

are directly overlain by the Trinity sand, although the 

Roubidoux beds of the Ellenburger are exposed along 

this road in the vicinity of the Llano River.

Eccyliomphalus gyroceras appears to be fairly common and seems to mark a very definite horizon in the 

Ellenburger limestone; it should therefore prove to be 

an extremely valuable index fossil in the Llano region.

Lecanospira sanctisabae (Roemer) 

Plate 67, figures 5a, b; plate 70, figures 1-5

1849. Euomphalus sanctisabae Roemer, Texas, p. 421.

1852. Euomphalus sanctisabae Roemer, Die Kreidebildungen

von Texas, p. 91, pi. 11, figs. 5a, b. 

1889. Straparollus sanctisabae. Miller, North American geology

and paleontology, p. 426. 

1915. Straparollus sanclisabae. Bassler, U. S. Nat. Mus. Bull. 92,

p. 1198.

1932. Lecanospira sanctisabae. Bridge, in Dake and Bridge, Geol. 

Soc. America Bull., vol. 43, p. 741, pi. 12, figs. 13, 14.

1933. Lecanospira sanctisabae. Bridge, in Sellards, Adkins, and 

Plummer, Texas Univ. Bull. 3232, p. 234, pi. 2, figs. 

13, 14.

ORIGINAL DESCRIPTIONS

9. Euomphalus sanctisabae, n. sp. Shell 1"2"' in diameter, 

fiat on the upper surface, whorls about six, increasing perceptibly 

in width, convex above, vertical cross section of the whorl oval.

Common in the white cherty Silurian limestone that forms the 

barren uplands on both sides of the San Saba River in the middle 

portion of its course. (See p. 339.)—Texas, p. 421.

8. Euomphalus sanctisabae

Plate 11, figures 5a, b

Euomphalus sanctisabae F. Roemer, Texas, p. 421. 

Diameter 1"8'", height 3"'

Shell flat above, discoidal, sinistrally coiled, whorls about six, 

gradually enlarging, slightly rounded, vertical section of whorl ovate, 

subrectangular; spire not elevated, concave beneath.

The shell is disk-shaped, sinistrally coiled, almost plane above. 

The whorls separated by a furrow, moderately numerous (about 

six), increasing slowly in breadth, on the upper side flat-arched, 

almost plane, in cross section oval, almost rectangular.

The single example before me is in the form of an internal 

mold and shows only traces of the enclosing shell in the form of 

white silica rings. In the specimen under discussion only the 

upper side is visible, but from the cross section of the whorl it 

is plainly seen that the under side is shallowly concave.

The almost plane upper side of the shell and the slowly increasing [diameter] of the whorl does not allow this form to be confused with any other.

Occurrence: The described specimen was found in bright-gray 

cherty limestone which contains many small cavities lined with 

druses composed of quartz crystals that glitter in the sun. 

[The limestone is] probably of Silurian age and forms the barren 

cliffs on both sides of the San Saba River in the middle portion 

of its course. (See above, p. 7.) In this limestone the species 

is not uncommon.

Explanation of the figures: Figure 5a, view from above; 

figure 5b, view seen from side opposite the aperture.—Kreidebildungen, p. 91.

REMARKS

The type specimen (no. 12) is an internal mold 

preserved in the dense white lithographic limestone that 

occurs in at least three well-defined zones in the Ellenburger limestone. The shell itself was partly silicified, 

and traces of it remain. The base of the shell (dorsal 

side of Roemer) is exposed and shows seven whorls 

coiled in a plane. Two sections are broken out from 

the final half of the body whorl, but enough remains to 

determine the position of the aperture with a fair 

degree of certainty. The opposite side of the specimen 

is almost completely covered by the white-limestone 

matrix, but the dorsal keel of the body whorl is plainly 

visible for about one-third of the length of the whorl. 

Some of the matrix was removed, revealing the keel of 

the penultimate whorl and showing plainly that the 

spire is depressed, but it was not advisable to attempt 

to clean the entire specimen. This keel is median. 

The cross section of the whorl, which is well exposed 

where the final whorl is fractured, is pentangular, with 

all the angles rounded except the one formed by the 

dorsal keel. The whorls are in contact to about onehalf of the height of the outer one and about threefourths of the height of the inner one. The whorls do 

not overlap sufficiently to form a smooth concave 

spire, the summit of each whorl being separated from
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 261

adjoining whorls by a sharp V-shaped groove, which 

carries the suture.

There is a very perceptible and regular increase in 

the width of the whorls, the ratio being 3:2 in any 

adjoining pair.

The surface markings and aperture are not preserved.

The depressed spire with its elevated dorsal keel and 

the flat or gently concave base are all characteristic of 

the genus Lecanospira, and this species is referred to 

it without question.

The maximum measurable diameter of the holotype 

is 40 millimeters; the computed diameter of the restored 

specimen is at least 47 millimeters; the diameters of 

the body whorl at the point where the first fracture 

occurs are, width 9 millimeters, height 10 millimeters; 

the diameters of the triangular fragment of the body 

whorl at a point estimated to be 20 millimeters from 

the aperture are, width 11 millimeters, height 12 

millimeters.

The species appears to be intermediate between 

Lecanospira compacta (Salter) and L. biconcava Ulrich 

and Bridge. The dorsal keel is median as in L. compacta, but the whorls are narrower and enlarge more 

slowly than in that species. They are broader and 

more rapidly expanding than those of L. biconcava, and 

the base is flat, not slightly concave as in L. biconcava.

OCCURRENCE

The locality from which the holotype was obtained 

is not at all definite, but from the narrative it was collected on the return trip from the San Saba River. As 

nearly as can be determined from his map, Roemer's 

route lay close to the meridian 98°50'. This meridian 

crosses the great plateau underlain by the Ellenburger 

limestone, which bounds the north edge of the Llano 

uplift at about the line of the present road from Pontotoc to San Saba. At several places along this road, 

particularly on the plateau around the headwaters of 

Wallace Creek, the present writer found ledges of 

dense white lithographic limestone carrying fragmentary specimens of Lecanospira sanctisabae, and it may 

well be that the holotype came from this general 

locality.

Several poorly preserved examples of what appears 

to be the same species were collected in 1931 by C. L. 

Dake on the high bluff on the north side of the Llano 

River about half a mile northwest of the concrete ford 

on the White ranch road. At this locality the first 

specimens were found in a prominent ledge on the southeast face of the hill about 165 feet above the flood 

plain of the Llano River, and above this point scattered specimens were found ranging through a zone at 

least 100 feet thick. In the upper part of this zone 

they are associated with a species of Roubidouxia,

79717—37——4

The white limestone containing these fossils is the 

middle one of three such zones in the Ellenburger limestone and is to be correlated with the Roubidoux 

sandstone of Missouri, with the Longview limestone 

and Nittany dolomite of the Appalachian Valley, and 

with an unnamed bed in the Arbuckle limestone of 

Oklahoma.

CARBONIFEROUS SPECIES 

By GEORGE H. GIRTY

Roemer cited five species from rocks of Carboniferous 

age. Four of these (Orthis arachnoidea, Terebratula 

pugnus, Productus flemingii, and Productus cora) were 

identified with described species; the fifth (Spirifer 

meusebachanus) was described as new. Terebratula 

pugnus and Productus cora were not figured, and there 

was, effectively, no text for Terebratula pugnus.

As regards geologic horizon, the four species first 

mentioned are stated to have been found in association. 

The horizon is undoubtedly in the Bend group, but 

whether it is Smithwick or Marble Falls is not so certain. Among the numerous collections from those 

formations at my disposal there is one especially (station 2602) which seems to have the same fauna and the 

same rock characters as Roemer's specimens. The 

horizon of this collection is given as Smith wick (?). 

Spirifer meusebachanus appears to have been found at 

a different locality and a different horizon from the 

rest. Bridge informs me that the rocks at the locality 

where he believes that specimen to have been collected 

are mapped as Canyon by the Texas Geological Survey.

The material examined as representing Roemer's collection comprises (1) the holotype of Spirifer meusebachanus, a free specimen (pi. 70, figs. 18-21); (2) a 

small slab purporting to contain the specimen figured 

as Productus flemingii (pi. 70, figs. 14 and 15); (3) 

another small slab purporting to contain the same 

original (pi. 70, figs. 16 and 17); (4) a large slab containing at one end the original of one of the figures of 

Orthis arachnoidea, together with specimens of Terebratula pugnus and more specimens of Productus 

Jlemingii (pi. 70, fig. 12); (5) a small slab split off from 

the large one last mentioned, which contains on its 

upper or outer surface a fragment from which was 

drawn the enlargement showing the surface characters 

of Orthis arachnoidea (pi. 70, fig. 13) and on its under 

side the reverse of the other specimen illustrated as 

Orthis arachnoidea.

Roemer's original plate is reproduced as plate 67 of 

this report; photographic reproductions of his original 

material are given on plate 70 as just described. As 

regards text, the species are taken up in the same order 

as. in Roemer's report, and his text is reproduced in full 

(translations by Bridge), followed by such comment 

and discussion as seem suitable.
262 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

Spirifer meusebachanus Roemer

Plate 67, figures 7a-c; plate 70, figures 18, 19, 20, 21

ORIGINAL DESCRIPTION

Spirifer meusebachanus F. Roemer, Texas, p. 420.

Width 2"3'", thickness 1"5'", length 1"9'"

Shell large, inflated, transverse, scarcely alate, radially plicate; 

with numerous plications, rounded, arranged in bundles; with the 

dorsal [ventral] valve ornamented with a deep median sinus and two 

lateral depressions; with the beak sharply inctirved; with an area 

3"' in height, with distinct vertical striations; with the ventral 

[dorsal] valve ornamented by a high median plication.

The shell is large, inflated, wider than high, almost triangular, 

slightly winged; the outer surface ornamented with many 

rounded branching costae, which are grouped into bundles 

containing three or four. These are crossed by widely spaced 

growth lines which occur only near the margins of the shell.

The dorsal [ventral] valve is provided with a broad, deep 

median sinus, as wide as the side [lateral slope] of the valve. Its 

broad, rounded, tonguelike point extends deeply into the ventral 

[dorsal] valve. On each side of the valve is a broad, shallow depression, which, when taken with the median sinus, causes the 

latter to appear to be bordered by a broad rounded ridge. The 

ventral [dorsal] valve is likewise strongly arched and is elevated 

in the middle into a high rounded fold, which is also ornamented 

with costae. The anterior margin is deeply notched for the reception of the tongue-shaped lobe of the dorsal [ventral] valve. 

The hinge line shows a moderately high area with plainly defined 

vertical striations.

The foregoing description and the figures are of a single, very 

beautiful and entirely complete specimen which was collected 

and presented to me by Mr. O. von Meusebach, the former 

general commissioner of the Association for the Protection of 

German Immigrants in Texas. He collected it while on our 

joint expedition in the San Saba Valley in the spring of 1847, 

from gray Carboniferous limestone at a locality about 20 miles 

below the old Spanish fort. (See F. Roemer, Texas, p. 314: 

ante, p. 7.)

I name this species for its discoverer, who had made scientific 

contributions before his emigration to America, as is witnessed 

by the collections of fossils from the glacial drift of the Mark of 

Brandenburg and Pomerania, which he has deposited in the 

Mineralogical Museum at Berlin, and who later on most cheerfully and unselfishly assisted me in pursuit of my geologic 

journey's goal in Texas.

Besides the specimen in question, which was used by preference as the basis for the description, there are before me a 

number of imperfect specimens which I collected at the same 

locality and which correspond [to it] in all respects. 

• The inequality and strong branching of the costae shows 

plainly that this is one of the Carboniferous species which is 

characterized by the fasciculate arrangement of the costae on 

the outer surface.

A comparison with similar species in the genus shows a close 

relationship to Spirifer tasmani Morris, 61 from Van Diemen's 

Land [Tasmania]. This last resembles the Texan species in the 

fasciculate arrangement of the costae and the general outward 

form of the shell but differs in the finer costae which ornament 

the sinus and fold and in the more limited depth of the sinus. 

Spirifer condor D'Orbigny,62 from Bolivia, is very close to the

61 Physical description of New South Wales and Van Diemen's Land, by Count 

iStrelecki, p. 250, pi. 15, fig. 2. Leopold von Buch, Die B&ren-Insel nach Keilhau 

geognostisch beschrieben, p. 11, figs. 3a, b (a beautiful illustration of a specimen 

now in the Berlin Museum).

82 Voyage dans I'Amerique mgridionale, par A. D'Orbigny, tome 3, 4eme partie, 

Palfiontologie, p. 46, pi. 5, figs. 11-14.

Texas species according to D'Orbigny's figure; but according to 

De Koninck, who has examined the original specimen, it is indistinguishable from Spirifer striatus Sowerby.

Explanation of the figures: Figure 7a, View of the outer 

surface of the dorsal [ventral] valve; figure 7b, view of the outer 

surface of the ventral [dorsal] valve; figure 7c, view from the 

side.—Kreidebildungen, p. 88.

REMARKS

The holotype is a fine specimen, and though it is 

somewhat idealized in the figures, a good idea of its 

characters can be had from them. Imperfections are 

present which are glossed over in the illustrations but 

are brought out in the photographs—for instance, the 

top of the fold and part of the sides are decorticated 

and also the arches that enclose the sinus. The dorsal 

view (fig. 7b) is somewhat misleading, for the fold is 

narrower, higher, and more strongly rounded on top 

than one would judge from the figure.

The surface markings are not well shown. They 

seem to consist of fine sublamellose incremental lines, 

some of which are stronger than the rest. These 

stronger lines vary in size and spacing; apparently only 

those that are especially pronounced are mentioned by 

Roemer. No fine radial striations have been observed, 

but if they were very fine they may originally have been 

present.

Roemer has mentioned the f asciculation of the costae, 

a feature which is in fact conspicuous. The fascicles 

are but slightly prominent, even near the hinge line, 

and farther forward they are essentially flat. They 

catch the eye because they are outlined by striae 

stronger than the rest.

S. meusebachanus has commonly been cited as a 

synonym of S. cameratus Morton. It is so treated 

by both Schuchert and Weller. At that time, however, S. cameratus was also made to include Spirifer 

triplicatus Hall. If the characters shown by the 

holotype are constant, S. meusebachanus is probably 

distinct from both the species mentioned. S. triplicatus is not so gibbous; it has finer and more numerous 

costae, and the fascicles are arched or subangular. 

Compared with S. cameratus (for example, the specimens which I figured from Putnam Hill, Ohio), S. 

meusebachanus is larger and much more gibbous, and 

it has a much more strongly developed fold and sinus. 

Large size, high convexity, and strength of fold and 

sinus are characters that are likely to accompany each 

other in specimens of any species, and it may be that 

smaller and younger specimens of S. meusebachanus 

would not be readily distinguished from S. cameratus.

The suggestion is carried on another page that the 

horizon of S. meusebachanus is probably higher than 

the Bend group, supposedly the Canyon group. As 

bearing upon this point, Spirifers of this general 

character are abundant in the Bend group, but none 

of those which I have seen are comparable to the
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 263

holotype of S. meusebachanus in perfection of preservation. They commonly occur ^as disconnected valves 

and are likely to be much exfoliated. They are more 

of the character of S. cameratus and regularly differ 

from Roemer's species in being much less gibbous. 

This evidence, for what it is worth, would suggest 

either that S. meusebachanus was not a Bend group 

species or else that the holotype is not really a representative specimen. Furthermore, some of the matrix 

still remaining in the cardinal area is a yellowish earthy 

rock—another piece of evidence that should be weighed 

cautiously.

Orthis arachnoidea Phillips

Plate 67, figures 9a, b; plate 70, figures 11, 12, 13

ORIGINAL DESCRIPTION

Orthis arachnoidea Phillips, Paleozoic fossils, p. 67, pi. 27, fig. 114. 

Spirifera arachnoidea Phillips, Geology of Yorkshire, vol. 2, pi. 

11, fig. 4.

The illustration shows the dorsal valve of a young specimen. 

The outline and the size and number of the branching, radiating, 

granular costae agree in all respects with those in specimens of 

Orthis arachnoidea Phillips, from the Carboniferous of England. 

However, I do not consider this identification to be indisputable, 

because there are not a sufficient number of specimens showing 

the various growth stages available [to make detailed comparisons].

Occurrence: In black, indubitable Carboniferous limestone, 

which also contains Productus flemingii Sowerby, Productus cora 

D'Orbigny, and Terebratula pugnus Sowerby, occurring in a 

tributary valley of the San Saba Valley.—Texas, p. 318; ante, 

p. 7.

Explanation of the figures: Figure 9a, View of a dorsal valve 

from above; figure 9b, a portion of the outer surface greatly 

enlarged.—Kreidebildungen, p. 89.

REMARKS

Synonymists have placed this citation under Derby a 

crassa, and such are its general but not, probably, its 

precise relations. Roemer has given us two figures of 

the species—one showing a valve in full, the other an 

enlargement of the surface. These two figures are 

based on different specimens. In one of the foregoing 

paragraphs it was remarked that the collection comprised two slabs that fit together, one small and one 

relatively large (pi. 70, figs. 11, 12). The specimen 

figured in full is on the large slab and is an internal 

mold of a brachial valve. It is nearly flat over most 

of its surface, but it is warped rather strongly downward near the lower right-hand margin. It was 

brought to light by breaking off the small slab, which 

on its lower side contains the interior of the same 

specimen, but its upper side exposes the specimen 

from which was drawn the enlargement to show the 

surface characters. The latter specimen, which is also 

a dorsal valve, is considerably larger than the other 

(nearly 30 millimeters in length), gently but irregularly 

convex, and in a poor state of preservation, being 

rather fragmentary and partly exfoliated,

As both specimens are dorsal valves, the generic 

position of the species is indeterminable, though the 

probabilities point to Derbya, or possibly Orthotetes. I 

have a pedicle valve, probably of the same species, from 

station 2902 (see p. 264), which shows the interior and 

affords evidence that the generic relations are in fact 

with Derbya. My specimen occurs in the same fauna 

as Roemer's, but this fact is not decisive. If Roemer's 

species can be referred to Derbya on these grounds, it 

differs from D. crassa in being more finely striated, and 

other differences may come to light when a more 

varied assortment of specimens representing both 

valves is brought together. The difference in the 

striation is conspicuous between Roemer's fossil and 

most specimens, possibly the more characteristic specimens, of D. crassa, but that species varies materially 

in the details of its surface sculpture, and the difference 

is not noticeable if some of the more finely striated 

specimens of D. crassa are used. Until the species 

from Texas is better known it would more prudently 

be cited as Derbya crassa var.

Terebratula pugnus Sowerby

Plate 70, figure 12

A small but indubitable example of this widely distributed 

Carboniferous species frequently occurs in the Carboniferous 

limestone of the San Saba Valley in association with the preceding species.—Kreidebildungen, p. 89.

As Roemer does not figure the species so designated 

nor give any of its characters save that it is small, I 

question whether his citation is a fit subject for inclusion in synonymy. Schuchert omits it; Weller cites 

it under Pugnax Utah. Although it seems desirable to 

say a little more about the species in this place, the 

present citation also would probably best be ignored.

Roemer's material contains several specimens evidently representing the species which he identified as 

Terebratula pugnus, all fragmentary or partly buried 

in matrix I have hesitated to take the necessary steps 

to determine the relations of this form, for that could 

not be accomplished without ascertaining its internal 

characters. The likelihood of any definite result in 

that direction seemed poor, and it is deemed wiser, at 

the present time, to leave the species in much the same 

state in which it comes from Roemer, except, of course, 

that any close relation to Terebratula pugnus cannot be 

admitted.

The best specimen is a dorsal valve, partly covered 

by matrix. It is strongly transverse and probably 

about 15 millimeters in width. The fold bears four 

plications and the lateral slopes about four each. The 

plications are large, rounded, and not traceable to the 

beak, the one nearest the hinge on each side being 

very faint. Internally the dorsal valve has a median 

septum which is short but of unknown height.

Presumably this species belongs in the genus Wellerella, if that genus is worth recognizing, but as com-
264 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

pared with W. osagensis (the Pugnax utah of former 

days), it is materially larger and somewhat more 

numerously plicated, the normal arrangement in W. 

osagensis being three on the fold and three on each 

side.

Marginifera roemeri Girty, n. sp.

Plate 67, figures 8a, b; plate 70, figures 12, 14, 15, 16, 17

ORIGINAL DESCRIPTION

Productus flemingii Sowerby, Min. Conch., vol. 1, p. 154, pi. 68,

fig. 1. 

De Koninck, Monographie des genres Productus et Chonetes,

p. 95, pi. 10, figs. 2a-l, fig. 3h. 

Produclus sp. ind. F. Roemer, Texas, p. 421, no. 7.

I have at hand several well-preserved specimens, none of 

which differ markedly in size from the one figured and which 

are therefore smaller than the customary size of this European 

species. According to De Koninck's own study of the Texas 

specimens, there is no doubt that they are conspecific with 

Productus flemingii Sowerby, the synonymy of which has been 

carefully worked out by De Koninck. Morever, there is a great 

similarity of outward form to young specimens of Productus 

semireticulatus Fleming—in fact, these two species, which are 

the most widely distributed [members] of the whole genus, are 

very closely related. The shell is comparatively thick, and on 

the inner surface [there are] deep small pits, which appear as 

coarse grains on the surface of internal molds. The dorsal 

[ventral] valve of a single specimen shows a sudden upward 

bending such as frequently occurs in Productus semireticulatus. 

Well-defined spine bases are scattered singly over the entire 

surface of the dorsal [ventral] valve, especially over the lateral 

slopes.

Occurrence: Several examples were found in association with 

the foregoing species in a tributary valley of the San Saba Valley, 

in black Carboniferous limestone in which this species seems to 

be the most abundant fossil.

Explanation of the figures: Figure 8a, external surface of the 

dorsal [ventral] valve; figure 8b, [the same] from the side.— 

Kreidebildungen, p. 89.

REMARKS

Roemer's two figures of this species are presumably 

different views of the same specimen, but some doubt 

surrounds the determination of the original. The 

species is obviously abundant, for it is represented by 

several specimens on each of the two small slabs and 

by a number of specimens on the large slab already 

mentioned several times. Accompanying labels indicate that both of the small slabs contain the specimen' 

figured. One slab (pi. 70, figs. 14, 15) contains a 

specimen which is uncovered (though partly by me) 

and agrees closely with the figures. It is, however, 

very slightly smaller and is imperfect at one side, 

whereas the figure shows an unbroken specimen. The 

other slab (pi. 70, figs. 16, 17) contains three specimens, 

two of which can be rejected as subjects of the illustrations. One (fig. 17, upper left) is too small, too 

finely striated, and in fact may belong to a different 

species; the other (fig. 17, lower left) is compressed and 

partly covered by matrix. The third specimen is on 

the edge of the slab and is not shown by figure 17, but a

posterior view is shown by figure 16. It is almost the 

counterpart of the specimen on the other small slab, 

but it is slightly wider and so in more exact agreement 

with the original figure. It is, however, partly concealed by matrix, and its surface characters are not so 

clearly shown as those of the other specimen. If either 

specimen alone is the original of the drawing, it is this 

One, but more probably the drawing is a composite 

picture of both. The broken specimen clearly shows 

evidence of Marginifera structure.

Schuchert includes Roemer's citation in the synonymy of Productus longispina, but with it he also 

includes Productus (Marginifera) splendens and Productus (Marginifera) wabashensis. Weller, too, includes Roemer's citation in the synonymy of Productus 

longispina and with it Productus (Marginifera) splendens. Productus (Marginifera) wabashensis he recognizes as a distinct species. The affinities of Roemer's 

form prove to be nearer to M. wabashensis than to M. 

splendens, but I regard it as distinct even from M. 

wabashensis and have it described in manuscript as 

Marginifera roemeri on specimens from my own collection (station 2602, 11 miles west of San Saba, Tex.). 

These specimens are to be regarded as the types of this 

new species. The associated fauna appears to be the 

same as that in which "Productus flemingii" occurs, 

and my specimens, which are numerous, agree with 

Roemer's.

Productus cora D'Orbigny

ORIGINAL DESCRIPTION

Productus cora D'Orbigny, Voyage dans 1'Amerique meridionale,

Paleontologie, p. 55, pi. 5, figs. 8, 9, 10 (male). 

De Koninck, Monographie des genres Productus et Chonetes,

p. 50, pi. 4, figs. 4a, b; pi. 5, figs. a-d. 

Productus sp. ind. F. Roemer, Texas, p. 421 (no. 6).

As a result of the investigations in western Texas, an entirely 

new locality is established for this well-known and widely distributed species, 63 which in North America is often confused with 

Productus scoticus Sowerby and Productus comoides Sowerby. 

According to D'Orbigny, who named the species, it was found at 

several places in the highlands of Bolivia. E. de Verneuil M has 

observed it at many places in the States of Kentucky, Ohio, 

Illinois and in New Scotland. The Texas specimens, so far as their 

incomplete preservation permits comparisons to be made, agree 

perfectly with specimens from Illinois, and in particular, the 

very fine costae that ornament the outer surface are the same in 

both. Moreover, the specimens are just as close to the European 

forms in size as those from Illinois, in that they are all scarcely 

more than 1 inch wide.

Occurrence: Common in association with the previously 

described species in the black Carboniferous limestone in a 

valley tributary to the San Saba Valley.—Kreidebildungen, 

p. 90.

REMARKS

Roemer does not figure the species which he refers to 

P. cora, and he does not describe it sufficiently for any

63 See De Koninck, op. cit., pp. 52, 53.

64 Note sur le parallelisms des depots paleozolques de 1'Amerique septentrionale 

avec ceux de I'Europe (extrait du Bull, de la Soc. geol. de France, 2eme serie, tome 4), 

p. 61.
REDESCRIPTION OF FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS 265

one to verify his identification. It is doubtful, therefore, whether his citation is substantial enough for 

synonymic recognition. In this respect it stands upon 

essentially the same plane as his citation of Terebratula 

pugnus. Accordingly, Roemer's citation is omitted by 

Schuchert but is placed in the synonymy of P. cor a by 

Weller. It is true that Roemer discusses the relations 

of P. cora at considerable length, but if perchance the 

different forms that he mentions (including the one 

from Texas) do not prove to belong to the same species, 

his discussion only contributes to confuse the subject. 

I am in a measure estopped from commenting upon 

the P. cora of Roemer because among his fossils there

is none which by any possibility could be referred to 

that species. I may say, however, that the faunas of 

Pottsville age in both Arkansas and Texas contain specimens of "Linoproductus" in more or less abundance, 

but I doubt whether P. cora is represented among them. 

Certainly the great majority of specimens where a 

decision could be reached do not belong to that species; 

they are more nearly allied to P. ovatus. Careful work 

may disclose grounds for distinguishing them from 

P. ovatus also, but as between that species and P. cora, 

the identification would lie with P. ovatus. These 

remarks are presumably applicable to the form that 

Roemer cited as P. cora.

PLATES 67-70

267
PLATE 67

Reproduction of plate 11, Kreidebildungen von Texas, 1852. Numbering of figures as in the original plate; page references refer to the present paper.

FIGURE 1. Pterocephalia sanctisabae Roemer (p. 246): a, Cranidium seen from above, the free cheeks wanting; b, cranidium in 

profile seen from the side; c, pygidium seen from above; d, pygidium in profile seen from the side.

FIGURE 2. Elvinia roemeri (Shumard) (p. 251): a, Cranidium seen from above; b, cranidium in profile seen from side.

Idahoia? sp. (p. 256): c, pygidium (cranidium) seen from above; d, pygidium (cranidium) in profile seen from the side.

FIGURE 3. Elvinia roemeri (Shumard) (p. 251): a, Pygidium seen from above; b, same in profile from the side.

FIGURE 4. Ophileta polygyrata (Roemer) p. 257): a, Shell seen from above; b, apertural view.

FIGURE 5. Lecanospira sanctisabae (Roemer) (p. 260): a, Shell seen from above [below]; b, apertural view.

FIGURE 6. Eccyliomphalus gyroceras (Roemer) (p. 258): a, Shell seen from above; b, cross section of the whorl.

FIGURE 7. Spirifer meusebachanus Roemer (p. 262): a, View of the dorsal [ventral] valve; b, view of the ventral [dorsal] valve; 

c, profile seen from the side.

FIGURE 8. Marginifera roemeri Girty (p. 264): a, View of the dorsal [ventral] valve from above; b, same from the side.

FIGURE 9. Orthis arachnoidea (Phillips) (p. 263): a, View of the dorsal valve; b, a portion of the surface enlarged.

FIGURE 10. Lingulepis acutangula (Roemer) (p. 244): a, View from above; b, same from the side. 

268
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 67

2b Ib

3b 2d 2c

9b

FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS AND SPECIMENS COMPARED WITH THEM.
U. S GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 68

39 40 41 42

FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS AND SPECIMENS COMPARED WITH THEM.
PLATE 68

FIGURES 1-6. Lingulepis acutangula (Roemer) (p. 244):

1. Ventral valve, the holotype, X 4.

2. 3. Ventral and profile views of the holotype, natural size. Locality 353, Wilberns formation, near Camp San Saba, Tex.

Museum of Geology and Paleontology, University of Bonn, Germany. 

4, 5. Dorsal and ventral valves from the Hickory (?) sandstone one-fourth mile east of Sandy post office, Blanco County,

Tex. U. S. Nat. Mus. 93009.

6. Owen's types of Lingulepis pinnaformis. Eau Claire formation, St. Croix Falls, Wis. U. S. Nat. Mus. 17860. 

FIGURES 7-43. Pterocephalia sanctisabae Roemer (p. 246):

7. Exterior and interior of two cranidia, the syntypes.

8. 9. Dorsal views of two large pygidia, paratypes A and B.

10, 11. Posterior and lateral views of paratype A.

12, 13. Dorsal and lateral views of a small pygidium, paratype C.

14. Under surface of another small pygidium, paratype D.

Specimens shown in figures 7-14 are Roemer's types, from locality 353, Camaraspis zone of the Wilberns formation, 

from the San Saba River near Camp San Saba, Tex. Originals in the Museum of Geology and Paleontology, 

University of Bonn, Germany.

15. 17. Cranidium and pygidium from Wilberns formation. Locality 70, near Morgans Creek, Burnet County, Tex. Plesiotypes. U. S. Nat. Mus. 93010.

16. 18. Cranidium and pygidium from Wilberns formation. Locality 353, San Saba River, half a mile east of highway bridge 

at Camp San Saba (pi. 1, B), McCullough County, Tex. Topotypes. U. S. Nat. Mus. 93012.

19. Cranidium from the Honey Creek formation, locality 9-1-2, northeast of Big Baldy Mountain, Wichita Mountains, Okla. 

U. S. Nat. Mus. 93014.

20. Cranidium from the Honey Creek limestone, locality 91-a, West Timbered Hills, Arbuckle Mountains, Okla. U. S. 

Nat. Mus. 93015.

21. Cranidium from the Honey Creek formation, locality 9-q, Blue Creek Canyon, 15 miles northwest of Fort Sill, Wichita 

Mountains, Okla. U. S. Nat. Mus. 93016.

22. Fragmentary cranidium showing the eye lines and the radial markings on the brim. Honey Creek formation, locality 

89-v, West Timbered Hills, NEK sec. 9, T. 1 S., R. 1 W., Murray County, Okla. U. S. Nat. Mus. 93017.

23. Small cranidium from the Da vis formation, locality 11-e, southwest of Potosi, Washington County, Mo. U. S. Nat.

Mus. 93018. 

24-26. Cranidia and pygidia from the Da vis formation, locality 11-k, near shaft of Federal No. 4 mine, Flat River, St.

Frangois County, Mo. U. S. Nat. Mus. 93019. Figure 26 shows association with Elvinia roemeri (upper left). 

27-30, 32, 39. A series of cranidia from shale in the Deadwood formation, north wall of Whitewood Canyon in the northern

ern part of Deadwood, S. Dak. 27, 29, 30, 39, Museum of the Department of Geology, University of Iowa; 28, 32,

U. S. Nat. Mus. 93020. Figure 32 shows characteristic association with Elvinia roemeri. 

31. Counterpart of figure 22, with an unusually well preserved brim. U. S. Nat. Mus. 93017. 

33-36. A series of pygidia from shale in the Deadwood formation; same locality as figures 27-30, 32. 33, 34, Museum of

Department of Geology, University of Iowa; 35, 36, U. S. Nat. Mus. 93020.

37. Cast of the pygidium of Dikelocephalus multicinctus Hall and Whitfield. Upper Cambrian, Eureka district, Nev. 

U. S. Nat. Mus. 24640. (The original specimen is a natural mold.)

38. Cast of natural mold of fragmentary cranidium, locality 60, across canyon from dump of Old Richmond mine, Eureka 

district, Nev. U. S. Nat. Mus. 93021.

40. Cranidium of Pterocephalia "laticeps" Hall and Whitfield. Upper Cambrian, lowest beds on west side of Pogonip 

Mountain, White Pine district, Nev. U. S. Nat. Mus. 24562.

41. Cast of a cranidium in the type lot of Pterocephalia laticeps which agrees in all respects with syntype B (fig. 7). The 

original specimen is a natural mold. U. S. Nat. Mus. 24562.

42. The same cast after slight lateral compression, showing the development of the characters of P. laticeps.

43. Cast of pygidium of P. laticeps. The original is a natural mold. Same locality as figures 40-42. U. S. Nat. Mus. 24561.

269
PLATE 69

FIGUEES 1-21. Elvinia roemeri (Shumard) (p. 251):

1-8. Roemer's types. All specimens from the Wilberns formation, locality 353, San Saba Valley, near Camp San Saba, 

McCullough County, Tex. Originals in the Museum of Geology and Paleontology, University of Bonn, Germany. 

1-3. Dorsal, frontal, and profile views of the larger cranidium, paratype A. 

4, 5. Dorsal and profile views of the smaller cranidium, paratype B. 

6, 7. Dorsal and profile views of the larger pygidium.

8. Dorsal view of the smaller pygidium.

9. Large cranidium selected by Walcott to replace Shumard's lost type. Wilberns formation, locality 70, near Morgans 

Creek, Burnet County, Tex. Plesiotype, U. S. Nat. Mus. 70259.

10. Pygidium, assigned to this species by Walcott. Wilberns formation, locality 68, top of west peak of Packsaddle Mountain, 

Llano County, Tex. U. S. Nat. Mus. 70261.

11. Cranidium figured as the type of E. "matheri" (Walcott), upper part of Potsdam sandstone, locality 110, near Whitehall, 

N. Y. U. S. Nat. Mus. 58585.

12. 13. Dorsal and profile views of cranidium from the Da vis formation, locality 11-k, near shaft of Federal No. 4 mine, Flat 

River, St. Francois County, Mo. U. S. Nat. Mus. 93011.

14. 16. Two cranidia from limestones about 100 feet above the sandstones at the base of the Deadwood formation, locality 

88-a, in the northern part of the town of Deadwood, S. Dak. The larger specimen preserves much of the test and 

consequently appears to be broader across the glabella than other specimens of equal size (figs. 9, 11, 12, 18) from 

which the test has been removed. U. S. Nat. Mus. 93024.

15. Cranidium from the Wilberns formation, locality 68, top of the west peak of Packsaddle Mountain, Llano County, Tex. 

U. S. Bat. Mus. 93013.

17. Type of Crepicephalus unisulcatus Hall and Whitfield. This is the specimen from which the original figure was drawn. 

From "limestone in the Potsdam group, Eureka, Nev." Unfortunately, the occipital ring was cut off when the print 

was mounted. U. S. Nat. Mus. 24574.

18. Cranidium identified as Crepicephalus unisulcatus by Walcott. Secret Canyon shale, locality 63, northeast of Adams Hill,

Eureka district, Nev. U. S. Nat. Mus. 24574. 

19-21. Cranidium and two pygidia from the Honey Creek limestone, locality 89-v, NE% sec. 9, T. 1 S., R. 1 W., West

Timbered Hills, Arbuckle Mountains, Okla. U. S. Nat. Mus. 93025. Figure 20 shows a mold of the outer surface.

22. Cranidium doubtfully referred to this species, locality 32-t, Upper Cambrian limestone in Fandango Spring Canyon, east

side of Dugway Range, Tooele County, Utah. U. S. Nat. Mus. 93026. 

FIGURES 23-26. Aphelaspis depressa (Shumard) (p. 255):

23. Roemer's specimen, a mold of a cranidium. Top of Cap Mountain formation, San Saba Valley, somewhere between 

Voca and Camp San Saba, McCullough County, Tex.

24. Frontal view of a squeeze made from the preceding.

25. 26. Cranidia selected by Walcott to replace Shumard's lost type. Locality 67, near Potatotop, Burnet County, Tex.

U. S. Nat. Mus. 90172.

FIGURES 27, 28. Idahoia? sp. (p. 256). Dorsal and profile views of Roemer's specimen. Wilberns formation, locality 353, San 

Saba River, about half a mile east of highway bridge at Camp San Saba, McCullough County, Tex. Original in the 

Museum of Geology and Paleontology, University of Bonn, Germany. 

FIGURES 29-34, 36, ?35. Ophileta polygyrata (Roemer) (p. 257):

29, 30. Dorsal and profile views of the holotype. Limestone of Gasconade age near base of Ellenburger limestone, on San 

Saba River about 20 miles east of Menard, presumably about half a mile east of the Mason-Menard County line, 

Mason County, Tex. Original in the Museum of Geology and Paleontology, University of Bonn, Germany. 

31, 32. Dorsal and profile views of the type of " Pleurotomaria hunterensis" Cleland. Tribes Hill formation, Fort Hunter, 

N. Y. Original in Museum of Cornell University, Ithaca, N. Y.

33. Dorsal view of the type of Polygyrata sinistra Weller. The healed fracture (p. 258) shows in the figure and intersects a 

recent fracture near the apex of the shell. The growth lines are best shown at the bottom of the figure to the right 

of the recent fracture. Specimen from the Kittatinny limestone, Columbia, N. J. Original in the New Jersey State 

Museum, Trenton, N. J.

34. Portion of the outer whorl of specimen shown in figure 33, X 4, to show growth lines. This is the same portion mentioned 

in the description of figure 33, but it has been rotated 180°. The irregular right-hand margin is the artificial fracture. Photograph by J. Brookes Knight.

35. A large fragmentary specimen doubtfully referred to this species. White limestone of Gasconade age, near the base of 

the Ellenburger limestone, in side valley on south side of San Saba River about half a mile east of the Mason-Menard 

County line, Mason County, Tex. U. S. Nat. Mus. 93027.

36. Another specimen from the same locality. U. S. Nat. Mus. 93027. 

270
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 69

FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS AND SPECIMENS COMPARED WITH THEM.
U. S. GEOLOGICAL SUEVEY PEOFESSIONAL PAPEE 186 PLATE 70

FERDINAND ROEMER'S PALEOZOIC TYPES FROM TEXAS AND SPECIMENS COMPARED WITH THEM
PLATE 70

FIGURES 1-5. Lecanospira sanctisabae (Roemer) (p. 260):

I—3. Dorsal, ventral, and lateral views of the holotype. Figure 3 shows the cross section of the whorl at the bottom of 

figure 2. Original from beds of Roubidoux age in the Ellenburger limestone from southwestern part of San Saba 

County, Tex. Specimen in the Museum of Geology and Paleontology, University of Bonn, Germany.

4. Ventral view of a specimen from the same horizon, location 469-b, north side of Llano River, 1% miles west of the mouth 

of Honey Creek and 265 feet above river level, Mason County, Tex. U. S. Nat. Mus. 93022.

5. Cross section of the specimen shown in figure 4, showing the outline of the whorls, the depressed spire, and the slightly

concave base. 

FIGURES 6-10. Eccyliomphalus gyroceras (Roemer) (p. 258):

6. 7, Roemer's types. His figure was clearly drawn from the specimen shown in figure 6. White limestone of Gasconade age 

at the base of the Ellenburger limestone in the San Saba Valley a short distance east of the Mason-Menard County 

line, Texas. Originals in the Museum of Geology and Paleontology, University of Bonn, Germany.

8. Two specimens from the same horizon, locality 471-e, \% miles north of Camp San Saba, McCullough County, Tex. 

U. S. Nat. Mus. 86949.

9. 10. Two specimens from the lower part of the Ellenburger limestone, west bank of Honey Creek, 2 miles south of the MasonLondon road. U. S. Nat. Mus. 93023.

FIGURES 11-13. Orthis arachnoidea (Phillips) (p. 263). The specimen at the top of the slab (fig. 12) is an internal mold of a dorsal 

valve, the original of figure 9a in Roemer. The slab shown by figure 11 was split off from the large slab and on its 

under surface, here in view, shows the interior of the same specimen. A large, imperfect dorsal valve on the upper 

surface of the same slab is'the original of Roemer's figure 9b, an enlargement showing sculpture. Figure 13 of this 

plate is a photographic enlargement (X 4) of part of the same shell.

FIGURES 11-17. Marginifera roemeri Girty, n. sp. (p. 264). Specimens of this species are seen on all the four slabs represented by 

figures 11, 12, 14-17, but Roemer's figures (8a, 8b) are probably a composite representation of specimens on the 

slabs shown by figures 14 and 17 of this plate. One of these is the upper specimen of figure 14, of which a side view 

is shown by figure 15. The other specimen is situated on the side of the slab represented by figure 17, and it does not 

appear in that figure. Figure 16 is a posterior view of this specimen. Roemer's figures, on the other hand, may 

represent either of these specimens singly, supplying the broken part if the original of figure 14 of this plate was 

used, or the part covered by matrix if the original of figure 17 of this plate was used. The specimen shown at the 

left in figure 17, though partly covered by matrix, is in good condition. It does not enter into this question, however. 

It is too small, too finely striated, and may not belong to the same species.

FIGURE 12. Terebratula pugnus (Sowerby) (p. 263). Roemer does not figure the species which he referred to T. pugnus, but several 

specimens are represented on the slab shown by this figure. The dorsal valve midway on the right side of the slab 

is the subject of Girty's comments.

FIGURES 18-21. Spirifer meusebachanus Roemer (p. 262). Four views of the holotype. Roemer did not give an anterior view 

corresponding to figure 19.

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