SOME AMERICAN CRETACEOUS FISH SCALES, WITH NOTES ON THE 

CLASSIFICATION AND DISTRIBUTION OF -CRETACEOUS FISHES. 

By T. D. A. CocKERELL. 

PREFACE. 

By T. w. STANTON. 

scales have been obtained from the Mowry 

shale, from the Aspen shale, and from other 

peds of about the same age in the areas where 

Fish remains are extremely abundant in these shales are not characteristically develseveral Cretaceous formations of the Rocky oped, but no attempt has been made to do 

Mountains and Great Plains, but except in thorough collecting even in these formations, 

the Niobrara formation of Kansas, a fish because no one in the Survey was qualified to 

skeleton well enough preserved for descrip- 1de:o.tify _,the scales. Tpe _scales from other 

tion or identification is the greatest rarity. formatioils in the same region have been 

The fishes are represented by separate scales, obtained incidentally in collecting invertebrate 

in some places associated with a few vertebrae fossils and are so few in number that they 

and other fragmentary bones or by isolated probably do not fairly represent the fish . 

teeth. In the original descriptions of both faunas of the seas in which ,the formations 

the Mowry and the Aspeh shales of Wyoming were deposite<.l. Similarly, the four species 

the presence of fish scales is mentioned as a based on scales from the Chico group were all 

characteristic feature. Fossils of other classes obtained in the Moreno formation at two . 

are usually very rare in beds containing many neighboring localities on the west side of San 

fish scales. Many of the scales 'are beautifully Joaquip. Valley, Cal., and can only be regarded 

preserved and show varied forms and more or as suggestive of the relationship, or lack of 

less complex sculpture. · relationship, between the Cretaceous fish faunas 

It had long been regretted that these fish of the Pacific coast and those of the Rocky 

scales had not been studied systematically, Mountain region. The enormously thick secand when several papers on the scales of tion referred to the Chico group in this part of 

living and fossil fishes ·were published by Prof. California has been divided by Anderson and 

Theodore D. A. Cockerell/ of the University of Pack 2 into the Panoche formation below and 

Colorado, Boulder, Colo., the hope was again the Moreno formation at the top. The Paquickened that these Cretaceous fish scales noche formation is said to have a maximum 

might prove to be of some value in strati- 'thickness of 21 000 feet and the Moreno formagraphic identifications and correlation. Prof. tion 2,500 or 3,000 feet. Fish scales are known 

Cockerell's offer to study fish. scales collected to be present 'in the Cretaceous formations of 

by the United States Geological. Survey was the Coastal Plain, extending from New· Jersey 

therefore welcomed, and early In 1916 the to Texas, but no attempt has yet been made 

material from the Western States was placed to assemble them for study. The collections 

in his hands. As a result of its study the ac- here treated are all of Upper Cretaceous agecompanying ;papei: has been pre~ared. . . that is, they are younger than the Comanche 

In connectiOn with the Surveys stratigraphiC and Shasta series. 

and areal work on the coal and oil fields of the A brief statement will show the relative 

Rocky Mountain region many small lots of fish stratigraphic positions from which the fish 

1 The scales of fresh-water fishes: Bioi. Bull., voL 20, pp. 367-386, 

1911. Observations on fish scales: U. S. Bur. Fisheries BulL, vol. 32, 

pp. 119-174, 1912. Some fossil fish scales: Zoo!. Anzeiger, Band 45, pp. 

189-192, 1914. Scales of Panama fishes: Washington Bioi. Soc. Proc., 

voL 28, pp. 151-159, 1915. 

scales described have been obtained and will 

explain why beds of approximately the same 

2 U.S. Geol. Survey Bull. 603, pp. 34-57, 1915. 

165 
166 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

age are referred to different formations in dif- I 

ferent areas. The standard marine Upper 

Cretaceous section of the Upper Missouri 

region is as follows: 

Montana group: 

Fox Hills sandstone. 

Pierre shale. 

Colorado group: 

Niobrara limestone. 

Benton shale. 

Dakota sandstone. 

In Colorado east of the Rocky Mountains 

and over a considerable part of the Great 

Plains a limestone (Greenhorn limestone) is 

developed in the midst of the Benton shale, so 

that the Benton shale interval consists of three 

formations-the Carlile shale, Greenhorn limestone, and Graneros shale. In parts of the 

same area the Niobrara is also separable into 

two formations-the Apishapa shale above 

and the Timpas limestone below. 

In the eastern half of Wyoming and around 

the Black Hills the Mowry shale is conspicuous 

in the lower part of the Colorado group as a 

hard, platy, ridge-forming shale, full of fish 

scales. In the Black Hills, where the Greenhorn limestone is recognized and the Benton is 

therefore divisible into three formations, the 

Mowry shale is treated as a member of the 

Graneros shale. In some areas where the 

Benton is not divided the Mowry is called a 

member of the Benton; in the Big Horn Basin 

it is recognized as ·an independent formation 

lying between the Frontier formation above 

and the Thermopolis shale below. 

The Aspen shale, which certainly includes 

rocks of the same age as the Mowry shale, is 

restricted to western Wyoming, which is also 

the typical area of the Frontier formation. 

The section there is as follows: 

• ,..s.; .. •· • 

Adaville formation. 

Hilliard shale. 

Frontier formation. 

Aspen shale. 

Bear River formation (restricted to western Wyom.ing). 

In this section the time equivalent of the 

Colorado group extends from the top of the 

Bear River formation to about the middle of 

the Hilliard shale, and the upper part of theMontana group is probably absent. In western Colorado the whole of the Colorado group 

and the lower part of the Montana group are 

represented by an undivided mass of shale 

called the Mancos shale, and this is overlain by 

the coal-bearing Mesaverde formation, followed by the Lewis shale and in the south ... 

west by the Pictured Cliffs sandstone. The 

Mesaverde formation is also recognized over a 

large part of Wyoming, and the only fish 

scales found in it were obtained in marine 

and brackish-water beds of the Rock Springs 

field. 

Another set of names has been used in northern Montana on account of the development 

of different s.tratigraphic units. There the 

great shale mass corresponding to the Mancos. 

extends only to the top of the Colorado group 

and is therefore called the Colorado shale. 

Above it in order come the Eagle sandstone, 

the Claggett shale, the Judith River formation, 

and the Bearpaw shale. Locally this succes--

sion is modified by the merging of the Claggett 

with the Eagle and Judith River and the de--

velopment ·of the Horsethief sandstone above 

the Bearpaw shale. 

The approximate relations of the abovementioned local subdivisions of the Colorado 

and Montana groups are shown in the following table: 
, ... - - ' "L ' ·-

Standard section, 

upper Missouri Eastern Colorado. 

region. 

--

.. Fox Hills sand- Fox Hills sandstone. stone. 

P. 

::i 

0 

tb 

~ 

~ 

...., ~ 

~ 

- Pierre shale. Pierre shale. 0 

~ 

-

-I I .. Apishapa shale. 

Niobrara limestone. 

Timpas lirp.estone. 

P. Carlile shale. 

::i 

0 

1-< 

1:JJ) 

O · Greenhorn lime- "0 

~ stone. 1-< 

0 

'0 

0 Benton shale. 

,, Graneros shale. 

Relations of locai subdivisions oj Colorado and Montana groups. 

Black Hills and eastern Southern Wyoming. East side of Big 

Wyoming. Western Wyoming. Horn Basin. 

----------------------- -------- -··-------------

Fox Hills sandstone. 

Lewis shale. Meeteetse formation (fresh water). 

-

--------- (?) --------- Pierre shale. Mesaverde forma- Mesaverde formation. tion. Adaville formation. 

Steele shale .. 

I -I I 

Cody shale. Hilliard shale .. 

Niobrara formation. Niobrara shale. 

' 

Carlile shale. Carlile shale. 

Greenhorn limestone. Frontier forma- Frontier forma- Frontier formation. tion. tion. 

<11 Mowry shale Mowry shale. :Mowry shale. 0 

~~ member. ~ <il ~,..>::l Aspen shale. 1-< 00 

C!l 

Thermopolis shale. Thermopolis shale. 

Western Colorado. 

Pictured Cliffs 

sandstone 

(southwestern 

Colorado). 

Lewis shale. 

Mesaverde formation. 

. 

I I 

Mancos shale. 

Northern Montana. 

-----------------------

Bearpaw shale. 

-

Judrth River for~ 

mation. 

Claggett shale_. 

Eagle sandstone. 

Colorado shal~. 

Ul 

0 

~ t_%j 

> 

~ t_%j 

!:d 

...., 

a 

> 

~ 

a 

~ ~ 

> a 

t_%j 

0 

d 

lfl 

1-o:j 

...., 

~ 

lfl 

0 

> 

t"" 

t_%j 

!'fl 

1--' 

~ 

~ 
168 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

INTRODUCTION. 

In offering a treatment of Cretaceous fishes, 

based principally on isolated or detached 

scales, one runs counter to the practice and 

prejudice of ichthyologists. The old scale 

classification of Agassiz has long been discarded 

and his terms are now used only in a descriptive sense. Even in that sense they ·are 

rather unsatisfactory, for there are many 

entirely different types of cycloid, ctenoid, 

and ganoid scales. Recent studies of the 

scales of living fishes show that they present 

excellent diagnostic characters and are highly 

distinctive of genera and families, though not 

alwa,ys of species. Very closely allied species 

may have scales which can not be distinguished, 

the scale characters being more persistent 

than some of the other more adaptive features 

on which the species are separated. Some 

scales, as might be expected, exhibit convergent 

or parallel evolution, showing similar features 

in quite different groups of fishes. Facts of 

this sort are likely to be misleading, · but they 

are in no sense peculiar to lepidology. 

In former years a few authors have undertaken to diagnose or recognize Cretaceous 

fishes from the scales alone. Dr. A. S. Woodward, influenced no doubt by the evident 

confusion in the application of the names, 

has set aside these determinations as practically 

valueless. It was not possible to give a really 

intelligible account of the fossil teleost scales 

until those of living fishes had been rather 

fully investigated. To-day the situation is 

different, and we feel justified in proceeding 

on a new basis. The situation is not unlike 

that found in paleobotany. Students of living 

plants do not describe species from leaves 

alone except in the rarest instances. Yet, if 

paleo botanists had refused to take note of or 

describe all plant remains that did not include 

the reproductive parts, our knowledge of the 

past history of vegetation would to-day be 

fragmentary indeed. It is true that many of 

the generic references of fossil leaves are provisional and uncertain, and it is very easy to 

criticize any paleobotanic work on this basis; 

yet no careful student of the subject can deny 

that on the whole the study of fossil leaves has 

been of immense value for the advancement of 

botanic science as well as for stratigraphy. 

Mter spending much time in the study of fossil 

plants as well as fish scales, I can affirm that 

the scales are certainly not less characteristic 

than the leaves; · in fact, the comparison is 

decidedly in favor of the scales. It can a~ '3o 

be said that the scales are at least as distinctive 

as the fragments of jaws, teeth, and fins that 

form the basis of so many descriptions of Cretaceous fishes. It is not, however, a question of 

scales versus bones, where both are available. 

Throughout the greater part of the American 

Cretaceous strata distinctive skeletal remains 

of fishes are extremely scarce; only in the Niobrara can they be said to be at all abundant. 

On the other hand, scales are plentiful and 

widespread and may be found in innumerable 

places where no other fossils are obtainable. 

Consequently, to refrain from studying these 

scales is to set aside a valuable aid to stratigraphy as well as a chance of learning in considerable detail what the teleost fauna of the 

Cretaceous really was. The Cretaceous was a 

time of extraordinary importance for ichthyology, because it saw the rise and development 

of the higher fishes, with numerous types clearly 

pointing toward the modern fauna. For this 

reason it is especially desirable to note every 

fact which will throw light upon the Cretaceous 

history. 

The study of fossil scales involves one difficulty. In studying modern fishes the investigator takes the scales 'from the middle of the 

side of the fish, where all their characters are 

fully developed. Scales from other situations 

may be quite uncharacteristic. Naturally ·no 

such selection has taken place in the preservation of the fossils, and consequently the specimens must be regarded with caution and set 

aside if there is any reason to think that they 

are not typical. Scales from the region of the, 

caudal peduncle will be comparatively narrow, 

but their sculpture and markings will be normal. Latinucleate (regenerated) scales are as 

common among fossils as in recent fishes, and 

should not be used as types. They can be, . 

distinguished by the confused sculpture of the 

central region, without the fine circuli around 

the nucleus. In describing scales the free end 

is spoken of as the apex, the a_ttached end as 

the base. The teleost scale is made up of fine· 

fibrillae, which· are in some genera longitudinal,. 

as in Amia and Albula, but more usually concentric. In the true clupeids (herrings) they 

are transverse. These fibrillae are termed the. \ 

circuli and are not growth lines. Growth lines. 
SOME AMEl iCAN CRETACEOUS FISH SCALES. 169 

have often been observed cutting he circuli. should be specially interested in Cretaceous 

In migratory fishes, such as the salmon, the fishes and did not pay particular attention to 

growth lines differ in character d density, their scales, except in the case of a few genera. 

according to the environment, 8!Ed conse- The authorities of the United States National 

quently it may be possible to detect evidence Museum and the American Museum of Natural 

of migratory habits in fossil fishes.! Lines or History very kindly allowed me to examine 

grooves radiating from the center olr the scale their materials. I am indebted to the Unior from its direction are called radii. This versity of Kansas for the photographs ef 

term was long ago used by Cope in /describing Hypsodon (Portheus), reproduced in Plate 

fossil fish scales; and it must be said of Cope XXXIII, figures 1 and 2. 

that his. descriptions of these struc1tures were As students of fossil scales will need specimuch better than those of most other authors, mens of recent species, it may be worth while 

though lacking in many desirable details. to explain a simple manner of preparing them. 

As in the case of fossil leaves, desariptions of Remove a few scales from the middle of the 

scales without figures are unsatisfa tory, espe- side of the fish, avoiding regenerated scales, 

cially if they are to be largely used !by stratig- and place them, while wet, upon a slide. The 

raphers who have no intimate knpwledge of skin covering the exposed part should be relepidology. Consequently it has been con- moved if it is thick. Cover the scales with a 

sidered necessary to illustrate this Raper fully; cover glass or, if they are large, with another 

and the enlarged figures, from pHotographs, slide. Hold down with one or more of the 

bear testimony alike to the excellent pJreserva- metal clamps used in microscopic work. 

tion of much of the material and 'the skill of Stick a gummed slide label on each side of the 

the photographer, Mr. W. 0. Hazard, of the cover glass, overlapping, or, if two slides are 

United States Geological Survey. pnly those used, round the ends of the slides. Remove 

species have been described and figp.red which the clamps when the material is dry, and the 

it seemed could be clearly recognized. Various scales will remain in place. 

others, evidently distinct but reprbsented by 

poor or uncharacteristic material, lhaYe been 

s'et aside for the present. Additi~nal collecS'fRATIGRAPIDC DISTRIBUTION. 

GENERAL FEATURES. 

tions, now that attention is called 0 the sub- ·In this discussion we are dealing almost enject, will undoubtedly greatly increase the tirely with a marine fauna. Scanty remains 

number of known species. I from the Judith River beds (see Acipenseridae) 

I am particularly indebted to Mr. T. W. are of fresh-water origin, but they do not inStanton, of the Survey, for assistan1

ce of every elude any teleost scales. It is not until we 

kind throughout this investigation. Without come to the base of the Eocene, in the Rocky 

his kind help I should have found it very :Mountain region, that we find scales of freshdifficult to proceed. I am also ~reatly in- water bony fishes/ and the species obtained 

deb ted to my colleague, Prof. J. Henderson, of present all the characters of the highly organized 

the .University of Colorado Museumr for advice modern group Centrarchidae (Micropterid~e). 

and assistance. Dr. D. S. Jordan has given The perchlike fishes are not found in American 

me much kind advice, though, of course, he is Cretaceous strata, and it is a question whether 

in no way responsible for my manner of treat- they may not have evolved in fresh water and 

ing the subject. He has furnishetl a rnanu- . later taken to the sea. At any rate, it must be 

script list of all the families and higher groups said that so far as we know at present the Tertiof ~hes, represen~ing his most m_atur,e opinions. ary fishes mark a considerable advan e on or at 

Th1s I have mamly followed m the present least change from their Cretaceous predecespaper. Dr. A. S~ Woodward, of ~he British sors. It ought to be possible ~s a rule to disMuseum, has sent me admirable photograph3 tinguish a Cretaceous from a Tertiary deposit 

of fossil fish scales, two of which I have repro- by means of a single well-preserved fish scale. 

duced (Pl. XXXVII, figs. 1, 2), alnd when I The exeeptions will be found in those groups 

was in London he kindly gave m~ access to 

the collections ·. of, the ; Museum.kl.l Unfortu- 1 A possible exception is u.s. Geological Survey Iocality-6603, in the 

Uinta Basin, Utah, whicl,l contains plant remains. Two, poorly prenately at that ·time I did not 1 OW that I served scal~ s are figured in Plate XXXVI, figures 16 and 17. 
170 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

which range with little change (rom the Creta- 1 Europe and America; and in America between 

ceous to the present day-the berycoids, clu- the faunas of the Atlantic seaboard, the inland 

peids, or hemiramphids. In such groups only sea, and the Pacific coast. All these regions 

the recognition of the species and its identifi- of course . had types in common, and these 

cation with one from beds of known age could appear to have been, at least principally, 

be of any service. , Such a scale as that of pelagic or open-sea organisms, such as UintaPomolobus? chicoensis, from the Chico, might crinus among the echinoderms and various 

belong anywhere from that time to the present sharks among the fishes. There were, howday. So, also, with Hemilampronites hesperius, ever, many differences. Scales of fishes from 

. from the Fox Hills. the Chico, cut off from the inland sea by the 

Just as the Tertiary fishes mark an advance western uplands, are all different from th~se in 

on the Mesozoic, so also the later Cretaceous Rocky Mountain deposits. The Chico has a 

fishes present evidence of evolution and mod- veritable clupeid, but so far no genuine clupeids 

ernization. This statement applies not only to have been found in the Benton, Niobrara, 

the Upper as contrasted with the Lower Creta- Pierre, or Fox Hills. The inland waters seem 

ceous, but also, and rather markedly, to the to have lacked berycoids, which are so characMontana group as contrasted with the Colo- teristic of the European strata. Comparisons 

rado group. The scanty materials from the between the Old World and the New World 

Fox Hills and Pierre now available already in- faunas are hindered by the difference in age of 

dicate the beginnings of modern groups which some of the abundantly fossiliferous deposits. 

are absent from the older beds, and ungues- Not only do the highly differentiated faunas of 

tionably later discoveries will emphasize the Hakel and Sahel-Alma in Syria (Mount 

distinctions observed. Thus we seem to find Lebanon) differ greatly from one another, but 

evidence of a rather slow and gradual modern- only about 10 per cent of their genera are 

ization of the fish fauna, the breaks in the series common to the American Cretaceous. They 

corresponding with the geologic breaks and not must be referred to a later horizon than our 

being attributable to any extraordinary migra- Cretaceous fishes. The Cretaceous of Westtions or sudden new developments. phalia .has more in common with the Syrian 

There were, however, certain environmental deposits than with the English . chalk and. 

conditions which must have affected the rate of should be intermediate in age between ·these 

evolution and diversification. The inland seas two. Nearly half the genera of the English 

of the American Paleozoic were drained by the chalk are represented in the Kansas Niobrara, 

Perl)lian uplift, but during later Mesozoic time though perhaps the chalk is for the ·most part 

this country once more possessed a vast med- somewhat older. I have prepared more elabiterranean sea, comparatively shallow and orate statistics, but owing to the uncertain 

warm, which reached its maximum depth prob- standing oJ a good many of th~ species they 

ably during the Niobrara epoch. A modern are not as valuable as they look on paper. 

map of North America marked in some way to The tendency of future investigations ·will 

indicate the shallow-water areas, even down to doubtless be to emphasize the differences in 

100 fathon:is, will show how restricted is the the faunas, especially as studies of scales are 

distribution of the present littoral and shallow- likely to reveal many of the smaller and more 

water faunas. They exist, as it were, in broad sedentary fishes. · 

rivers running mainly north and south. They Prof. J. Henderson, who has paid much atare circumscribed by climate, by land, and by tention to the Upper Cretaceous Mollusca, 

the open sea. · In comparison the great Creta- informs me that in his experience all the species 

ceous inland sea must have afforded an amazing of the Benton differ from those of the Niobrara, 

wealth of opportunity for multiplication and and all those of the Niobrara from those 9f thE> 

development, which may well have been the Pierre. The Pierre and Fox Hills, on the other 

decisive faett>r in the evolution of many groups hand, present faunas grading one into the 

of marine o!ganisms. . other. As this did not wholly agree with some. 

In this connection it is interesting to inquire of the published records, I asked Mr. T. W. 

whether there were radical differences between l Stanton.! or his opinion. He replies that he is 

the supposedly contemporaneous faunas of in ·perfect accord with Prof. Henderson. · The 
SOJ'viE AMERICAN .CRETACEOUS FISH SCALES. 171 

Colorado and Montana faunas had few if nny 

identical species of Mollusca, though of course 

many genera occurred in both. _ Old records 

contrary to these opinions were based on 

errors. · . Thus Inoceramus labiatus, supposed to 

occur in the Niobrara of Kansas and Nebraska, 

was really from the Greenhorn limestone, well 

down in the Benton. We have, then, in the 

Upper Cretaceous two extremely marked 

faunal breaks. They must represent long 

periods, during which many things happened. 

Where no species of Mollusca persisted, surely 

no fishes could be expected to remain unaltered. 

Present information tends to confirm this 

opinion, and when a Benton fauna is found in 

beds ascribed to the Niobrara (see under 

Holcolepis pulchellus, p. 174) it is evident that 

there was an error in stratigraphy. 

BENTON SHALE. 

The previously recorded teleosts from the 

Benton are few, as follows: 

Apsopelix. A genus not known from later rocks. Mr. 

Stanton informs me that Cope's locality (in Kansas) is 

certainly Benton. 

Pelecorapis varius Cope. Mr. Stanton says almost certainly from the Benton; the · Inoceramus referred to by 

Cope is presumably I. labiatus. Mr. Stanton adds, however, that if the Sibley referred to is the one now on the 

map there is some mistake, a,s this would place the 

locality in the Carboniferous. 

Protosphyraena bentoniana Stewart. 

Hypsodon lowii (Stewart). This and the last belona to 

genera common to the Niobrara and Pierre. e, 

There is also a very dubious record of Anogmius. To these are added in the present paper 

the following species : 

Holcolepis pulchellus 1 n. sp. 

Holcolepis delicatus n. sp. 

Holcolepis transversus n. sp. 

Holcolepis obliquus n. sp. 

Hypsodon? granulo.sus n. sp. 

Ichthyodectes sp. 

Leucichthyops vagans n. sp. 

Erythrinolepis mowriensis n. sp. 

Halecodon denticulatus n . sp. 

Cimolichthys sp. 

It is not at present certain that levels in the 

Benton can be distinguished by means of the 

fishes. Materials ascribed to the Aspen (for 

example, U. S. G. S. localities 4874, 3870) present a Mowry fauna, as they should, ·for the 

Aspen and Mowry are approximately equivalent. 

t The rocks yielding this species were ref~rred to the Niobrara by 

Beekly (U.S. Geol. Survey Bull. 596, pp. 40, 41, 1915), butthe IocaJ.lty is 

in a faulted area and may well be on a Benton outcrop. 

NIOBRARA FORMATION. 

The recorded fish fauna 'of the Niobrara is 

very rich, comprising 23 genera, mostly found 

in Kansas. Several of these · are discussed 

below, but I have no new species to add. 

MONTANA GROUP. 

The Montana group includes the Pierre shale 

and Fox Hills sandstone. The fishes are not 

sufficiently well known to throw any particular 

light on the divisions of the group. The following new forms, the last three of which are from 

the Fox .Hills sandstone, are described in this 

paper: 

Petalolepis? fibrillatus n. sp. 

Cycloides? incertus n. sp. 

HypBodon? radiatulus n. sp. 

Echidnocephalus? americanus n. sp. 

Helnrintholepis vermiculatus n. sp. 

Gyclolepis stenodinus n. sp. 

Hemilampronites hesperius n. sp. 

Acc~rding to previous records about half a 

dozen Niobrara genera (Hyposodon, Syllaemus, 

Protosphyraena, Ichthyodectes, Empo or Oimolichthys, and perhaps Pachyrhizodus) survived 

to the Pierre ; but not one of these is recorded 

from the Fox Hills. This means little, perhaps, as hardly anything has been known of the 

Fox Hills fishes. 

CHICO GROUP. 

The following species from the Moreno formation f the Chico group of California are 

described below: 

Chicolepis punctatus n. sp. 

Pomolobus? chicoensis n. sp. 

Erythrinolepis chicoensis n. sp. 

Echidnocephalus? pacificus n. sp. 

DESCRIPTION AND SYSTEMATIC DISCUSSION OF 

SPECIES. 

PISCES. 

Subclass CHONDROSTEI. 

Family ACIPENSERIDAE. 

Scutes of Acipenser (A. toliapicus Woodward) 

are known from the London clay (lower Eocene) 

of the Isle of Sheppey. The plates named A. 

cretaceus Daimeries, from the Senonian of 

Belgium, are said by vVoodward to belong 

apparently to some fish related to Dercetis or 

Eurypholis, and therefore are not chondrostean 

at all. In the Belly River formation (Upper 
172 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Cretaceous) of Red Deer River, Alberta, Elopidae, being shaped much like the sole of 

Lambe found a scute which he called Acipenser the foot, the nucleus subapical, with coarse conalbertensis. In the same deposit he found part centric circuli above it, the lower margin 

of an elongated snout which bore a series of broader and thin, neither crenulated nor with 

teeth, much like that of the more ancient radii. The albulid scale, on the other hand, is 

Saurorhynchus (Belonor-hynchus). This he subquadrate, with broad crenate lower margin 

named Diphyodus longirostris, but he did not and a few distinct basal radii. The albulid 

attempt to indicate its affinities. It was after- fibrillae are tuberculate, as in 'the Dipneusti; 

ward stated by Hatcher 1 that remains similar this ia not true of Alepocephalus. 

to both these fossils were common in the Judith In view of their primitive characters, the AlRiver and Lance formations in certain localities bulidae must have existed in the Cretaceous. 

in Montana and Wyoming. The associated The recorded species which have been assigned 

fossils indicated fresh-water conditions, so the to this family, however, do not appear to beabsence of such remains from the Upper Cre- long there. Prochanos is to be referred to 

taceous marine beds is not surprising. The Chanidae. lstieus goes in Pterothrissidae. 

question naturally arises whether by any possi- Ancylostylos from Croatia may be referred to a 

bility the Acipenser, so called, was in fact a distinct family, of which it is the typical genus. 

toothed sturgeon, Diphyodus representing the Anogmius Cope (Syntegmodus Loomis), from 

jaw of the same fish. The Saurorhynchidae the Niobrara of Kansas, may go in Pterothrissiseem not to have survived to the Cretaceous dae, but not in Albulidae or Osteoglossidae, to 

(Stenoprotome Hay, from Syria, being a very which it has been referred. Plethodns forms a 

dubious representative), but it is possible that family, Plethodontidae, to which Hay also 

toothed sturgeons more or less intermediate refers Anogmius. Apsopelix, to judge from 

between the Saurorhynchidae and Acipenser- Cope's description of the scales, seems to have 

idae existed in that period. some resemblance to the Albulidae, where it is 

Subclass TELEOSTEI. provisionally placed by Hay. Cope states that 

the circuli are vertical, except in the region of 

Order HALECOMORPHI. the nucleus. The position of this genus must 

Family PROTOSPHYRAENIDAE. for the present remain undecided. Finally, 

Protosphyraena Leidy (Erisichthe Cope) IS Petalolepis divaricatns (Geinitz), based on a 

abundantly represented in the Niobrara of scale from tbe Turonian of Saxony, appears to 

Kansas and has one species each in the Benton be a genuine albulid. An American scale IS · 

and Pierre. It is known mainly by the rostra provi.;;ionally referred to the same genus. 

and pectoral fins, and there is in the descrip- Genus PETALOLEPIS steinla. 

tions no mention of scales. Hypsocormus, conPetalolepis? fibrillatus Cockerell, n .. sp. sidered to be related to it, has sriwoth scales, 

small and deeply imbricating. _ Plate XXXI, figure 1. 

Scale 8.5 millimeters in diameter, subquad- Order ISOSPONDYLI. rate, but with obtusely rounded angles, a very 

Family ALBULIDAE. little longer than broad; lines of growth evil have supposed that the Albulidae (Albula dent, concentric, but the very fine fibrillae 

and Dixonina) were the only fishes above the strictly longitudinal from one end to the other, 

Halecomorphi that had longitudinal basal except that toward the basal margin they curve 

circuli or fibrillae.2 I find, however, that this inward, becoming more or less transvers~, folpeculiarity is shared by Alepocephalus agassizi lowing the wavy outline of the margin; the 

(Alepocephalidae). Benthosphyraena macrop- fibrillae are not tuberculate or beaded, as tbey 

tera, also referred to the Alepocephalidae, has are in Alb1.da; as in Petalolepis divaricatus, on 

small round scales wholly unlike those of Alepo- each side of the middle line in the basal region 

cephalus. The Alepocepha;lus scales, although the fibrillae become curved and end by meeting 

having longitudinal basal fibrillae, are in other each other at a very acute angle; there is a 

respects entirely different from those of the strong median plica on the· basal half of the 

. scale, but no ordinary radii, and this agrees 

with P. divaricatus. . 1 U. S. Geol. Survey Bull. 257, p. 69, 1905. 

2 U. S Bur. Fisheries Bull., vol. 32, p. 122, fig. 2, 1912. 
SOME AMERICAN CRETACEOUS FISH SCALES. 173 

U.S. G. S. locality 5094. Cretaceou.;, Mesa 

Verde formation, 14 miles north of Rock 

Springs, Wyo., a little east of center of sec. 26, 

T. 21 N., R. 104 W. (Collected by V. H. 

Barnett.) 

A similar but much larger scale may represent a related species, but the surface as preserved presents a very fine irregular reticulation, with concentric lines of growth, and it can 

not be determined whether the fibrillae are 

longitudinal. · So far as the visible characters 

go, this agrees with Winkler's problematic 

Gycloides, and it may provisionally stand as 

described below. 

Cycloides? incertus Cockerell, n. sp. 

Plate XXXI, figure 2. 

Scale 16 millimeters in diameter (C. incisus 

Winkler is 17.5 millimeters in diameter), subquadrate; apical margin broadly rounded, 

apparently a little crimped; laterobasal angles 

obtuse but distinct; a very strong median 

plica on the basal three-fourths, the growth 

lines turned upward on approaching it, as in 

Winkler's figure. 

U. S. G. S. locality 5177. Cretaceous, Mesaverde formation, about 5 miles southwest of 

Sycamore, Wyo., in the NE. 1 sec. 12, T. 19 

N., R. 103 W., in the Rock Springs region. 

(Collected by V. H. Barnett.) 

In the general form and median plica this 

scale is suggestive of that of Mugil curema. 

The same sort of plica and basal margin may 

be seen in scales of the cyprinid Cirrhina 

jullieni. There is also a. conspicuous median 

basal plica . in Chanos, but it is broad and 

shallow, not forming a line. 

Family LEPTOLEPIDAE. 

A family found in the Cretaceous of Europe, 

surviving from the older Mesozoic. ''Scales 

thin, cycloidal, and deeply imbricating, usually 

ganoid in their exposed portion; lateral line 

not observable." (A. S. Woodward.) 

Fami~y ELOPIDAE. 

Genus HOLCOLEPIS Von der Marek. 

This genus was called Rhabdolepis by Von 

der Marek in 1863, ·but Troschel had earlier 

(1857) used that name for a palaeoniscid fish. 

Holcolepis was proposed in 1868. Agassiz, 

who had proposed the name Osmeroides for an 

entirely different fish, unfortunately trans282880--19----12 

ferred it in 1844 to a specie~ of Holcolepis~· and 

in this he has been followed by several authors. 

The genus Holcolepis is certainly to be referred 

to the Elopidae, even after the removal of such 

genera as Pachyrhizodus, which A. S. Woodward places in that family. The teeth are 

minute, entirely di;fferent from those of Pachyrhizodus. The dorsal fin is less modified than in 

modern Elopidae. Holcolepis has not hitherto 

been reported from the North American Cretaceous, our nearest form being Spaniodon 

simus Cope, a form with smooth scales. 

A. S. Woodward 1 described the scales of 

Holcolepis 'as "often ornamented in their exposed portion with delicate radiating lines of 

minute tubercles, marked in their covered portion with a few radiating grooves terminating 

in notches at the anterior truncated margin; 

hinder margin not serrated; course of lateral 

line indicated by a feeble ridge and a notch in 

the hinder border of most of the scales"-that 

is to say, the scales have basal radii; but in a 

later publication 2 Woodward shows a scale of 

Osmeroides lewesiensis ( = Holcolepis lewesiensis) without any such radii. 

Osmeroides divaricatus Geinitz, 1868, is 

based on the scales of an albulid fish, and 

takng up the name Petalolepis Steinla, published by Geinitz as a synonym, the species 

becomes P etalolepis divaricatus. 

Osmeroides lewesiensis (Mantell) as determined by Geinitz from the Turonian of Saxony 

consists of a mixture of different things, none 

of them identical with the English fish. One, 

the most recognizable, is similar to the living 

genus Pterothrissus in the character of its 

scales. This form 3 unfortunately takes the 

cumbersome name Kymatopetalolepis of Steinla 

and may stand as K. geinitzi n. sp. It has 

four to six fanlike basal radii, the circuli between them broken into dots. The nucleus 

is subapical, and the apical region hyaline. 

Osmeroides divaricatus Geinitz as figured by 

Fritsch 4 is wholly unlike the Geinitz species, 

having transverse basal circuli. There are 

three basal radii, and the basal margin is scalloped. 

1 Catalogue of fossil fishes in the British Museum, pt. 4, p. 11, 1901. 

2 The fossil fishes of the English chalk, pl. 23, fig. 8, 1907. 

a Geinitz, H. B., Die Fossilen Fischschuppen aus dem Plltnerkalke in 

Strehl en: Gesell. N atur- u. Heilkunde Dresden Denkschr., 1868, pl. 2, 

figs. 10-12. 

4 Fritsch, Anton, Die Reptilien und_Fische der bohmischen Kreideformation, fig. 58, 1878. 
174 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

0. lewesiensis (Mantell) of Fritsch is also 

wrongly named. It is a scale with subapical 

nucleus and five strong basal radii, the basal 

margin very strongly scalloped. The scale 

has a strong resemblance to that of Megalops 

cyprinoides, and may therefore represent a 

fossil elopid of some unknown genus. 

Osmeroides belgicus Winkler, 1874, is based 

on a scale apparently congeneric with the socalled lewesiensis of Fritsch but considerably 

broader and with more basal radii. It is a 

large soale, the transverse diameter being 15 

millimeters. 

The type of Holcolepis, H. cretaceus Von der 

. Marek, is imperfectly known, and it is possible that the various species supposed to ·be 

congeneric could be divided into two genera 

with better materials. For the present I 

assume that the scale of H. lewesiensis, well 

figured by Woodward, is typical of the genus. 

Its most characteristic feature is the pseudoctenoid exposed area, ornamented with radiating lines of pustuliform markings, derived 

from the circuli. H. latijrons (Woodward), 

from the chalk of Kent, is similarly ornamented, 

but the lines are more broken up, producing, 

except near the margin, a pitted or malleate 

effect. The lateral line is very distinct. In 

H. levis (Woodward), from the chalk of Kent 

and Sussex, the scales possess ''fine radiating 

ornament" and have distinct basal radii. 

They are therefore similar to those of the 

modern Elops, and the fish may not be congeneric with the others. 

The modern Elopidae (Elops, Tarpon, Mega-

'lops) have very distinct basal radii, 3 in Tarpon, 

about 5 to 7 in Megalops, and 12 to 18 in Elops. 

'rhe basal margin is very strongly crenate in 

Megalops, moderately in Tarpon, but feebly 

in Elops. In Tarpon the apical field has a 

radiati:rig sculpture of minute tubercule-like 

elements, not clearly visible on casual inspection. This is the Holcolepis sculpture, but 

very much finer and less conspicuous. In 

Megalops the region above the nucleus shows 

granulations but not distinct radial lines; 

there is some approach to the condition of 

Holcolepis latijrons. Elops, above the nucleus, 

shows coarse transverse wrio..kled lines, but the 

broad apical field is free from markings derived 

from the circuli and presents a number of 

parallel radii. Apparently, then, the early 

elopids (Holcolepis) had the exposed , part of 

the scale prominently sculptured with lines or 

rows of tubercles derived from the -circuli, 

while the covered part was either without 

evident sculpture, except the fine circuli, or 

had a few distin~t radii. The development 

has been toward the loss of the ·apical sculpture and the strengthening and increase in 

number of the basal radii. It seems that these 

changes were in process or even perfected as 

early as the Cretaceous, but typical Holcolepis, 

as here understood, included the more primitive type. Pachyrhizodus, to judge from the 

figure of a scale of P. subulidens (Owen) published by Woodward (reproduced in Pl. XXXII, 

fig. 3), had scales of the Holcolepis type, with 

strong or coarse sculpture on the exposed portion, and the base rounded and without radii. 

The scale was parallel-sided, and longer than 

broad, the reverse being true of typical Holcolepis. Thus, though we may well place Pachyrhizodus in a distinct family, it may have had 

a common ancestor with the elopids, possessing 

the Holcolepis-like scale. 

In the American Cretaceous fauna the 

species described below, based on scales, are 

referred to Holcolepis, as understood in a 

rather broad sense. Outside of the Elopidae 

the scales show a certain general resemblance 

to those of Aulopus (Aulopidae), but in that 

genus the margin is strongly dentate. 

Holcolepis pulchellus Cockerell, n. sp. 

Plate XXXI, figures 3, 4. 

Scale 7 millimeters in diameter, approximately 

cireular, the apical margin obtusely angulate 

in the middle; nucleus only a Jittle above the 

middle; lower margin not at all crenate; six or 

seven basal radii very eebly indicated, not 

distinctly developed, not definitely eutting the 

circuli; apical field with very numerous parallel raised lines, but to" ard the nucleus with 

wavy lines as in Elops. 

One mile south of the oetcher ranch, in the 

NE. l SW. l sec. 32, T. 0 N., R. 81 W., North 

Park, Colo. (Collected y A. L. Beekly and 

Harvey Bassler.) · This i Beekly's locality 37.1 

It is referred to tlle Ni brara, but the seales 

from this and several oth r localities referred by 

Beekly to the Niobrara r semble those from the 

Mowrv and are therefo e believed to have 

come from the Benton shale. All the localities 

1 Beekly, A. L., U. S. Geol. Survey Bull. 596, p. 42, 1915. 
SOME AMERICAN CRETACEOUS . FISH SCALES. 175 

thus under suspicion failed to yield any characteristic Niobrara :Mollusca, and the collection 

from ,Beekly's locality 59, which did include 

Ostrea congesta Conrad, offered no -su~h scaleR, 

hut only one of 1chthyodecte8, the so-called 

'' Oladocyclus .'' 

H. pulchellus was also ,found on the northwest shore of Lake John, in the SE.i SW. l sec. 

34, T. 10 N., R. R1 w~, North Park, Colo., 

by Beekly . and Bassler. This is Beekly's 

locality 35. 

Holcolepis delicatus Cockerell~ n. sp • . 

Plate XXXI, :figure 5. 

Scale 1.0 millimeters in diameter, stibcircular1 

similar to H. pulchellus, but apical margin 

rounded, nucleus a little below· the middle; 

lines of exposed area finer and denser, with more 

or less evident pits between; only vague i~distinct suggestions of basal radii. 

Big Horn Basin, in the SE. l SE. l sec. 15, 

T. 43 N., R. 94 W., Wyoming. Near baseof 

Mowry shale. (Collected by C. T. Lupton.) 

. Holcolepis transversus CockerE~ll, n. sp. 

Plate XXXI, :figures 6-13. 

Scales subquadrate, ·on side~ nearly twice as 

broad as long, on other parts often narrow, 

varying to about as broad as long;· latero basal 

angles commonly rather prornin~nt; apical 

margin broad, flattened or depressed in middle, 

not angular; no basal radii, but often a single 

median fold, rather indistinct; apical modified 

patch V -shaped, ornamented with a series of 

closely set interrupted ridges, without pits between; circuli fine) the lateral ones directed upward, meeting the margin at a Yery acute angle; 

nucleus approximately central. 

Type a scale 9 millimeters in diameter, from 

U. S. G. S. locality 6682, Slate Creek, 1\1ount 

Leidy quadrangle, Wyo. (Collected · by Eliot 

. Black\velder.) Mollusks of this locality , are 

said to be not characteristic and may belong 

either in the Montana group or the upper part 

of the Colorado group, but the fish scales indicate Colorado (Benton) age. Other scales in 

the same lot, referred ·to this species, are 11 

millimeters and 14 millimeters in diameter. 

I also refer to this species the following: 

U. S. G. S. locality 6681. Cretaceous, probably Aspen, Slate Creek, Mount Leidy quadrangle, Wyo. (Collected by , Eliot Blackwelder.) Scale 10.5 millimeters in diameter .. 

U.S. G. S.locality 6713. Cretaceous, Mowry 

shale, southeast of camp at old chimney, Sisters 

~ill, Buffalo, Wyo. (Collec~ed by 0. B. Ilopkins.) Scale 9 millimeters long and 11 millimeters wide; another scale 7 millim~ters wide. 

The two f9llowing specimens are about as 

broad as long and probably came from the . 

vjcinity of the caudal peduncle. 

U.S. G. S. locality 4421. Mowry shale, Casper region, sec. 29, T. 33 N., R. 74 W. sixth 

principal meridian, Wyoming. · (Collected by E. 

W. Shaw.) · Scale 12.5 millimeters in diameter. 

U. S. G. S. locality 3417. Lo,ver (Benton) 

part of Mancos shale, Steamboat Springs, 

Routt County, Colo., on ridge near mineral 

springs, just west of town and south of Yampa 

River. (Collected J11ly 13, 1905, by T. W. 

Stanton and H. S. Gale.) . 

Holcolepis transvers1l8 is closely related tp H. 

8teinlai (Geinitz), published by Geinitz as Acrogrammatolepis steinlai, the figure upside down. 

The FJ. steinlai scale i)<s 7 by 6 nlillimeters and 

has the nucle11s. apparently more basally placed 

than in H. transvers·us. It is from the Turonian 

of Saxony and may very likely be identical 

with the English H .. lewesiensis (Mantell), from 

beds of about the same age. 

Holcolepis obliquus Cockerell, n. sp. 

Plate XXXII, :figure 1. 

Scales 10 millimeters in diameter, much 

broader than long, without any trace of basal 

radii. Similar in most respects to H. transversus, but remarkable for the brevity of the 

elements in tb.e apical patch and for the lateral 

circuli being oblique, at the middle of the side 

reaching the margin at an angle of about 45°, 

and above this becoming almost transverse. 

Type collected with H. transversus, in Mowry 

shale at U. S. G. S. locality 4421. Details are 

given above . 

Holcolepis? mandible. 

Plate XXXII, :figure 2. 

In confirmation of the existence of.a typically 

elopid type of fishes . in the North American 

Cretaceous, I give a figure of a mandibular 

ramus which seems to belong to Holcolepis ,or 

a closely related genus. It differs from that of 

H. lewesiensis in the straight (not concave) 

descending upper margin of the dentary, and in 

this respect mote resembles the modern Elops. 
176 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

It was collected by _A. C. Veatch in the 

NW. ! SW. ! sec. 8, T. 19 N., R. 79 W., 

Carbon County, Wyo., and is ascribed to the 

Colorado group. . From the associated scales, 

which include an imperfect specimen of Holco-

:zepis, either pulchellus or a closely related 

:species, I infer that the material is from 

the Benton. r The mandible and the Holcolepis 

scale probably belong to the same species. 

Genus RHACOLEPIS Agassiz. 

Dr. _D. S. Jordan has kindly sent me material 

of Rhacolepis buccalis Agassiz, from the Cretaceous of Ceara, Brazil. The scales are broad, 

with coarse, rather widely spaced circuli, transverse above and below the nucleus, and many 

of them broken or anastomosing above the nucleus. The apical margin is delicately plicate, 

with a series of parallel ridges, very much as 

in Otenothrissa. This marking probably corresponds with the system of apical radii of 

Elops and has nothing to do with the pseudoctenoid sculpture, derived from the circuli, of 

Holcolepis. Rhacolepis is therefore entirely 

distinct from Holcolepis, and the scales can 

not be confused. It is just possible that the 

Pachyrhizodus scale, which seems from Woodward's figure (reproduced in Pl. XXXII, fig. 

3) to be of the same general type as that of 

Holcolepis, is really constructed in the manner 

of Rhacolepis, but with the shape entirely 

different and the apical plicae much longer. 

Genus NOTELOPS Woodward. 

In the Brazilian Cretaceous Notelops brama 

(Agassiz), also received from Dr. Jordan, the 

circuli are :finer and denser than in Rhacolepis. 

I can not make out any "delicate radiating 

ridges," mentioned by Woodward, but the 

material is not very good. Jordan and Branner 1 state that the scales are cycloid and 

entire. They are, in any event, wholly distinct from those of Rhacolepis. 

Genus HELMINTHOLEPIS Cockerell, n. gen. 

Scale cycloid, circular, or slightly longer 

than wide, about 17 millimeters across in the 

type; nucleus a little below the middle; . circuli fine, concentric on basal half but longitudinal and very wavy, like minute worms, on 

apical half; the apical marginal area delicately longitudinally striate, with about five 

1 Smithsonian Misc. Coli., vol. 52, p. 9, 1908. 

circuli between each pair of strire or :fine radii. 

This may not be elopid,. but I do not know 

where better to refer it. The striate margin 

is like that of Hypsodon, but there are no 

tubercles, and the microscopic . structur~ is 

very different. There are no radii in the basal 

field, and the lower margin is broadly rounded. 

Type H. vermiculatus. 

Helmintholepis vermiculatus Cockerell, n. sp. 

Plate XXXII, figure 4. 

Diameter about 17 millimeters. 

U. S. G. S. locality 9184, Cretaceous, Fox 

Hills sandstone, north side of Thompson 

River, near top of ridge about 1! miles northeast of Milliken, sec. 1, T. 4 N., R. 67 W., 

Greeley quadrangle, Colo. (Collected by T. E. 

Williard.) The type scale partly overlaps a 

scale of Hemilampronites hesperius. 

Family PTEROTHRISSIDAE. 

The interesting family Pterothrissidae is 

represented. to-day by Pterothrissus Hilgendorf 

(Bathythrissa Guenther) fro:tn deep water off 

Japan. It is related to the albulids, but the 

scales have the circuli of the median and basal 

regions (a large mverted v -shaped area) broken 

up into dots and fine rugae. In the Cretaceous 

rocks of Westphalia and Syria the family is 

represented by the genus Istieus, the scales of 

which are said to be elliptical, not pectinated 

(A. S. Woodward). Anogmius, from the Niobrara of Kansas, seems to 'be more or less 

related. Kymatopetalolepis geinitzi Cockerell, 

based on scales from the Turonian of Saxony, 

appears to be typically pterothrissid. Ohicolepis, a new genus from the Chico, may also be 

referred to this family. 

Genus CHICOLEPIS Cockerell, n. gen. 

Scales· broad, subquadrate, shaped as in 

Pterothrissus, with very broadly rounded apical 

margin; nucleus apical, v.ery near the margin; 

sides with dense simple longitudinal circuli, 

passing vertically up to the apical margin; the 

whole area inclosed by lines drawn from the 

middle of the apex to the laterobasal corners is 

cov:ered with minute punctiform dots, the circ~li having combined to form an extremely 

dense honeycomb-like reticulation, the punctures round and often running more or less 

in transverse series. In the region of the 
SOME AMERICAN CRETACEOUS FISH SCALES. 177' 

lateral circuli are here and there streaks of 

punctured surface. No ordinary radii, but a 

median line or plica from base to apex, most 

conspicuous on basal half. This superficially 

resembles Petalolepis? .fibrillatus, but its struc-

·ture is very different. Type, 0. punctatus. 

Chieolepis punctatus Cockerell, n. sp. 

Plat e XXXIV, figure I. 

Scale 16 millimeters in diameter; laterobasal 

corners :rectangular. 

U. S. G. S. locality 7030. Cretaceous, Chico 

group, south side of Ortigalito Creek, Cal., in 

Moreno formation. (Collected by Robert Anderson.) For further description of locality 

see Pomolobus chicoensis. The absence of the 

ordinary radii at once distinguishes this species 

from Pterothrissus and Kymatopetalolepis. 

Family ICHTHYODECTIDAE. 

The fishes assigned to the Ichthyodectidae 

can not be referred to Chirocentridae; the scales 

are radically and entirely different from those 

of the living Ohirocentrus, and the teeth are 

implanted in deep sockets. Stewart also seems 

fully justified in separating the Saurodontidae, 

especially on account of the remarkable unpaired predentary. 

Genus HYPSODON Agassiz. 

The type of Hypsodon is H. lewesiensis, but 

unfortunately Agassiz included under this 

name fishes that were 'not even congeneric. 

Cope·, commenting on this fact, remarked that 

Hypsodon included some fishes with teeth of 

equal length and others in which they were 

unequal. He proposed to redtrict the name to 

the genus having equal teeth, and according 

to this decision Hypsodon would ·take the place 

of the genus later named Pachyrhizodus by 

Dixon. However, the specific name lewesiensis was adopted from Mantell, who had described the fish with unequal teeth as Megalodon? lewesiensis. It is this fish which Agassiz 

figured in" Recherches sur les poissons fossiles," 

volume 5, Plate :XXVa, figure 3, and Plate 

:XXVb, figures 1-3. This appears to fix the 

type in a contrary sense to Cope's decision, and 

Hypsodon takes the place of Portheus Cope. 

Stewart suppressed Portheus in favor of 

Xiphactinus Leidy, which was based on a 

pectoral fin spine of the same species as Cope's 

type of Portheus. Hypsodon is much older, and 

the giant fish of the Niobrara rocks will take 

the name Hypsodonaudax (l..:~ei y). Portheus 

mantelli Newton, from ·the English chalk, becomes Hypsodon lewesiensis (Mantell). In 

America the genus is · well represented in the . 

Niobrara and has one species, Hypsodon lowii 

(Portheuslowii Stewart), in the Benton .. 

The University of Kansas has remarkably 

well preserved material · of H . audax, and 

through the kindness of Prof. S. J. Hunter I 

have received photographs of the scales, which 

are reproduced here. 

Hypsodon audax .(Leidy) Co~kerell. 

Plate XXX II, figure 8; Plate XXXIII, figures 1, 2: 

Xiphactinus audax Leidy, Acad. Nat. Sci. Philadelphia 

Proc., p. 12, 1870; U. S. Geol. Survey Terr. Rept., 

vol. 1, pp. 290, 348, pl. 17, figs. 9, 10,' 1873. · 

Cope, U. S. Geol. Survey Terr. Rept., vol. 2, p. 276, 

1875 . . 

Hay, Zool. Bull., vol. 2, p. 27, 1898. 

Stewart, Kansas Univ. Quart., yol. 7, p. 115, 1898; 

idem, vol. 8, p. 107, 1899; Kansas Univ. Geol. Survey, vol. 6, p. 267, pls. 33-47, 1900. , 

Saurocephalus audax (Leidy) Cope', Am . . Philos. Soc. Proc., 

· vol. 11, p. 553, 1870; U. S. Geol. Survey Terr. Ann. 

Rept. for 1870, p. 418, 1871. 

Portheus? audax (Leidy) Hay, U. S. Geol. Survey Bull. 

179, p . 384, 1902. 

Scales extremely broad, the width about 

twice the length, though on the caudal peduncle 

they are undoubtedly much narrower. Exposed area densely covered with small tubercles, 

which in the apical region are arranged in longitudinal series, being in fact situated on longitudinal ridges. The ·basal region has fine concentric lines of growth, and numerous more or 

less broken radii, spread out in broad fan 

shape. The Oladocyclus occidentalis of Leidy, 

which has page priprity over X iphactinus 

audax, is based on just such scales, but whether 

of the species H. audax it is no't at present possible to decide. Loomis thought the 0. occidentalis scales belonged to Ichthyodectes (or 

Gillicus) arcuatus Cope, and wrote Ichthyodectes occidentalis (Leidy) for ,that species. 

This assignment certainly can not be maintained. It appears that the type locality of 

0. occidentalis is uncertain: On one page Leidy 

says that the material came from Nebraska; 

on another he says that it came from Sage 

Creek, Dakota. Leidy suggested that the 

scales before him probably belonged to several 

species. 
178 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

The name Oladocyclus Agassiz was based on 

scales from Brazil (0. gardneri Agassiz), which 

do not appear to be identical with any of the 

North American or European genera, though 

there is close similarity in the branching lateral 

line canals. I have material of the Brazilian 

fish, kindly sent by Dr. D. S. Jordan. Woodward, in his "Fossil fishes of the English 

chalk," abandons the use of Oladocyclus for 

European fishes, remarking that Agassiz referred to this genus scales of the Ichthyodectes 

type, calling them all Oladocyclus lewesiensis. 

The scales which Geinitz called Oladocyclus 

strehlensis were in the main of this same type. 

The question which now arises is whether 

scales of Hypsodon can be clearly distinguished 

from those of Ichthyodectes. Woodward figures 

Ichthyodectes scales, and they differ from those 

of Hypsodon only in the strictly entire basal 

radii. In Ichthyodectes, as I understand it, 

the basal part of the scale frequently splits 

along the radii, · producing the appearance of 

a frayed edge of separated narrow bands. The 

lateral line canal is branched, more or less 

Y -like, or rarely in the complex manner of the 

Brazilian Oladocyclus. A photograph of 

"Oladocyclus lewesiensis," received from Dr. 

A. S. Woodward, shows the fraying-out effect 

v~ry well and should represent Ichthyodectes. 

The species of Hypsodon and Ichthyodectes recorded from the Kansas Niobrara are numerous, 

and it will be difficult or impossible to connect 

them all up with their scales. 

A very fine sca-le, 40 millimeters long and 35 

millimeters broad, comes from the N_iobrara of 

New Mexjco (U. S. G. S. locality 8354, Meloche 

ranch, eastern edge of .Raton quadrangle; collected by W. T. Lee). It is not at all of the 

same shape as the Kansas University H. audax 

scales, but it presumably comes from the caudal 

region, and is similar to one of the scales 

figured by Leidy as Oladocyclus occidental·is. 

The striae in the apical region are very delicate, 

and the tubercles are between the ridges instead of upon them; but this is probably a 

reverse impression. In view of the large size 

and general agreement in characters this scale 

is referred to H. audax. 

A still larger H. audax scale comes from 

Wyoming (10 miles southeast of Glenrock, in 

the SW. l NE. l sec. 29, T. 33 N., R. 74 W.; 

collected byV. H. Barnett); it is 51 millimeters 

across. 

Typical II. audax scales, about 50 millimeters across, have been found in the Mancos 

shale 1! miles northeast of Columbine, Routt 

County, Colo. (Collected by Colorado Geological Survey.) 

Hypsodon lowii (Stewart) Cockerell. 

Plate XXXIV, figure 2. 

Portheus lowii Stewart, Kansas Univ. Quart., vol. 7, p. 

24, pl. 2, fig. 2, 1898. 

Hay, U. S. Geol. Survey Bull. 179, p. 384, 1902. 

Xiphactinus lowii (Stewart) Hay, Zool. Bull., vol. 2, p. 

27, 1898. 

Stewart, .Kansas Univ. Geol. Survey, ~ol. 6, p. 293, 

pl. 48, fig. 2, 1900. 

U. S. G. S. locality 7294. Cretaceous, 

Benton, sec. 20, T. 9 N., R. 77 W., half a mile 

northwest of Kerr's ranch, North Park, Colo. 

(Collected by A. L. Beekly and Harvey Bassler.) 

A large scale, 32 millimeters across, provisionally referred to H. lowii, as it is exactly the 

sort of scale that species might be expected 

to have. 

Hypsodon? radiatulus Cockerell, n. sp. 

Plate XXXII, figures 6, 7. 

Scale 15 millimeters across, with apical 

ridges but apparently without the tubercles of 

H. audax. Another scale, 15.5 millimeters 

across, is of the same species but latinucleate 

(renovated). As this species comes from a 

later formation than the Niobrara, it is· doubtless distinct from the Kansas fishes described. 

U. S. G. S. locality 5177. Cretaceous, Mesa 

Verde, about 5 miles southwest of Sycamore, 

Wyo., in the NE. l SE. l sec. 12, T. 19 N., 

R. 103 W., in th~ Rock Springs region. (Collected by V. H. Barnett.) Oycloides? incertus 

is from the same locality and horizon. 

U. S. G. S. locality 5174. Cretaceous, 'Mesa 

Verde, about 2~ miles north of Sycamore, Wyo., 

in theSE. l sec. 17, T. 20 N., R. 102 W. 

Hypsodon? granulosus Cockerell, n. sp. 

Plate XXXII, figure 5. 

Scale nearly circular, slightly broader than 

long, about 21 millimeters in diameter, ba.sal and 

apical margins rounded; circuli fine, co~- . 

centric, except in large exposed area extending 

to the region of the nucleus in the center of the 

scale, where the surface is finely rugose, without 

the definite tubercles of Fl. 'a·uilax; apical margin longitudinally striate but not tuberculate; 
SOME AMERICAN CRETACEOUS FISH SCALES. 179 

base with about a dozen imperfect and broken 

radii. 

U.S. G. S.locality 4874. Cretaceous, Mowry 

shale, 100 double paces south of the north 

quarter corner of sec. 19, T. 28 N., R. 91 W., 

near North Rawiins, Wyo. (Collected hy 0. P. 

Hopkins.) I 

It is possible tlhat this species and Flj.? radiatrulus belong to elopid fishes, and not tq the Ichthyodectidae. With H.? gr-anulosus occurred 

Leucichthyops v.agans and I-Iolcolepis trams·ver-sus. 

Genus ICHTHYODECTES Cope. 

Plate XXXIV, figures 3, 4. 

About eight species of lchthyvdectes ate known 

from the Niobrara of Kansas. Three species 

occur in the chalk of England. 'Fhe type 

species is I. ctenodon Cope from l{a:q.sas. At 

present we can do no more than recognize the 

genus fron· the scales; it is doubtful whether 

the scales exhibit specific characters. The two 

following are characteristic: 

U. S. G. S. locality 2402. Cretaceous, lower 

part of Colorado shale, creek north of Lower 

Sherburne Lake, Swift Current Valley, tributary to St. 1\1arys River, :Mont., latitude 48° 

S0-.5.5', longitude 113° 25'. (Collected by 

Bailey Willis ttnd Stuart Weller.) Scale 6 

millin1eters in diameter. 

U. S. G. S. Ideality 7277. Cretaceous, Niobrara, in the NE. i SE. i sec. 34, T. 7 N., 

R. 82 W., east of Clover Valley telephone line, 

about 3 or 4 miles south of Butler, North Park, 

Colo., yellow sandy material. (A. L. Beekly.) 

This is Beekly's locality 59.1 Ostrea congesta 

occurred in the 1 same material. 

Ichthyodectes seales also occur in Benton 

rock north of Boulder, Colo., where they were 

collected bv Prof. J. Henderson (Colorado 

Univ. Mus." 459). One of these scales, 15 

millin1eters in transverse diameter and about 

11 millimeters long, is fron1 the lateral line and 

is remarkable ~or the con1plex, treelike system 

of branching canals, quite as complex as in tlie 

Brazilian Cladocyclus. This species tends to 

weaken our convietion that Ichthyodectes and 

Cladocyclus ar~ really different genera; but the 

scales of Oladocycl?.ts gardneri differ in the basal 

1 U. S. Geol. Survey Bull. 596, p. 42, 1915. 

region from those of lchth·yorlectes, and in view of 

the difference of loeality there is no great probability that the fishes are really congeneric. 

1\foreover, as A. S. Woodward shows, 0. gardneri differs also from lchthyodectes in the more 

anterior position of the dorsal fin. 

Ichthyodectes libanicus (Pictet and Humbert), 

from Syria, which I have examined in the 

American lYiuseum of Natural History, has 

very broad scales, smooth and porcelain-like 

on their exposed parts. Woodward states that 

the species has the dentition of Ichthyodectes. 

Cretaceous fish scales from Turkestan. 

Plate XXXIV, figures 6-12. 

G. D. Romanowsky 1 has figured certain Cretaceous seales from Turkestan, and the figures 

are reproduced on Plate IV. 

Figures 6, 7, 8, referred by Romanowsky to 

Oladocyclus strehlensis Geinitz, agree with 

Hypsodon. 

Figure 9, referred to Osmeroides lewesiensis 

var., appears to be immature Hypsodon, the 

scale probably from the subcaudal region. 

Figure 10, referred to Oladocyclus strehlensis, 

agrees with Ichthyodectes. 

Figure 11, ealled Osmeroides pectinolepis 

Romanowsky, is imperfect and apparently 

latinucleate (regenerated); it may be Ichthyodectes. 

Figure 12, ealled Beryx .sp., can not be determined. It shows nothing to justify a reference to the genus Beryx. 

Family PLETHODONTIDAE. 

The scales of Plethodus are unknown; the 

species are distinguished by the form of the 

dental plates. Anogmius Cope, well represented in the Niobrara of Kansas, is placed in 

the Plethodontidae by Woodward and Hay. 

Its former reference to the Osteoglossidae was 

manifestly incorrect; no Cretaceous Osteoglossidae are known, nor are they likely to be 

found in marine strata. The scales of Anogmius polymicrodus Stewart, as described by 

A. S. W ooclward, are "moderately thick, showing only lines of growth; they appear to have 

been deeply overlapping." 

1 Materialui dlya geologii Turkestanskago kraya, pts. 2, 3, 1884, 

1890. 
180 SHORTER CONTRIBUTIONS TO GENERAL· GE.OLOGY, 1918. 

Family CL UPEIDAE. 

Genus POMOLOBUS Ra:finesque. 

Pomolobus? chicoensis Cockerell, n. sp. 

Plate XXXIV, figure 5. 

Scales . 4.2 millimeters broad, considerably 

broader than long, cycloid, with the hyaline 

apical margm at most slightly crimped; covered portion with very fine strictly transverse 

circuli; a more or less distinct median longitudinal groove or fold on basal half; three transverse radii, the second and third interrupted in 

middle, the interval a 'little greater than half 

the length of either lateral division. 

U.S. G. S. locality 7030. Cretaceous, Chico 

group, south side of Ortigalito Creek, Cal., 1 

mile above the mouth of its canyon and 11 

miles northeast of Erreca's, in base of gully 

draining north along west line of the SW. l sec. 

28, T. 11 S., R. 10 E., and joining Ortigalito 

Creek near center of west line of section. In 

shale of Moreno formation, below the fossilof Syllaemus latifrons Cope, the type of the 

genus, and the circuli are not transverse, as 1n 

Clupeidae.2 

Family SALMONIDAE. 

Genus LEUCICHTHYOPS Cockerell, n. gen. 

Scales similar in type to those of the living 

L eucichthysnigripinnis (Gill); cycloid, the apical 

margin broadly rounded, the basal with a broad 

llledian lobe, ' the margin more or less coneave 

between this and the rather promin·ent laterobasal angles.; ·apical radii weak, about as in 

Leucichthys,· no basal radii; circuli fine, eoncentric; growth lines very distinct, probably 

indicating that th~ fish was migratory. Scales 

from caudal region are narrower. Lateral line 

scales have a prominent canal, expanding 

basally. Type L. vagans. 

Leucichthyops vagans Cockerell, n. sp~ 

Plate XXXIV, figure 13; Plate XXXV, figures 1-15 . . 

iferous conglomerate. (Collected by Robert The type scale is from U. E?. G. S. locality 

Anderson.) . 7095 and has a diameter of 9 millin1eters. It 

This scale exactly agrees with the living genus is distinctly bro~der than long. The exact 

Pomolobus, differing from P. pseudoharengus locality is t.he NW. l SW. l see. 20, T. t'l N., 

(Wilson), from Lake Ontario, only in the di- R. 79 W., 1 mile southwest of Dean's ranch, 

rectly transverse, not distinctly oblique broken North Park, Colo. This is Beekly's locality 

radii. It is very likely that other parts of the 19, supposed to be Niobrara but to judge from 

fish would reveal generic distinctions, but per- the fishes apparently Benton. The following 

haps it is not impossible that Pomolobus dates are also referred to this species, although they 

from the Upper Cretaceous. It is a singular may represent more than one species, . 'not 

thing that such a type should be found in the readily if at all separable on scale characters. 

California Chico . but should wholly fail to ap- The scales differ greatly in shape, but only as 

pear (so far as my material shows) in the strata might be expected on different parts of the fish. 

east of the Sierra Nevada, whereas to-day · 1. Scales of the same general form as the 

Pomolobus and its close relative Alosa are found type. , . 

only in tl:).e north Atlantic and (Alosa) Medi- Colorado group, in the NW. i SW. i sec. 

terranean. With reference to the antiquity of S, T. 19 N., R. 79 W., Carbon County, Wyo. 

the clupeid type, it may be noted that A. S. Scale 12 .. 50 millimeters long and broad. Also 

Woodward 1 describes a fish from the Lower second seale, incomplete. 

Cretaceous of Bahia, Brazil, as Scombroclupea U. S. G. S. locality 3880. Near base of 

scutata, . and remarks that it does not differ Mancos sh.ale, 4 miles east of Meeker. Colo. 

much from Olupea itself. Typical Scombro- Scale ll.millirneters in diameter. 

clupea comes from the much later rocks of Graneros ~b,.ale, Little Spring Creek, northMount Lebanon, in Syria, and it is very prob- east corner of Sturgis quadrangle, Black Hills, 

able that the Brazilian fish, when better known, in .reddish rock. In · addition to normal scales 

will prove generically distinct. In the North there is a large latinucleate (regenerated) one 

American Cretaceous we have recorded only 13 nrillimeters in diameter. 

one supposed clupeid type, Syllaemus Cope U. S. G. S. locality 7275. Lower Benton, 

(Leptichthys Stewart). I have examined scales J north bank of Norris Creek about 200 yards 

1 London Geol. Soc. Quart. Jour., vol. 64, p. 360, 1908. 2 Zool. Anzeiger, Band 45, p. 190, 1914. 
SOME AMERICAN CRETACEOL[S FISH SCALES. 181 

north of Norris house, 12 to .14 miles south of 

Walden, in the NE. ! SW. ! sec. 13, T. 8 N., 

R. 82 W., North! Park, Colo. (Collected by 

A. L. Beekly.) 'l1lis is Beekly's locality 57.1 

A large scale, dia111eter 14.5 millimeters. 

2. Narrow scales, presumably fronl the 

caudal pedunele. 

U. S. G. S. locality 6681. Probably Aspen, 

Slate Creek, :Mount Leidy quadrangle, Wyo. 

(Collected by Eliot Blackwelder.) Scale about 

9 millimeters acrqss, distinctly convex. II olcolepi8 tra.ns'l'er8us[ occurs at the same locality 

and horizon. . 

U.S. G. S. locality 7110. Probably Benton, 

Beekly's locality 37.2 Scale 8.2 millimeters 

across. Holcolepis pulchellus occurs .at the 

sam.e localitv and horizon. 

U. S. G.~ S. locality 8916. l\Iowry shale, 

Big Horn Basin, Wyo. (Collected by C. T. 

Lupton.) For exact data see description of 

Holcolepis delica.tus (p. 175), which occurred 

with it. The narrow · Lwucichthyops scale is 

accompanied by others of the normal type. 

3. Broad, lateral line scales. 

U. S. G. S. locality 6682. Cretaceous, probably Colorado group, Slate Creek, Wyo. (Collected by Eliot Blackwelder.) Accompanied 

by a typical scale of the same species and by 

scales of II olcolepis tra.nsversu,'J. 

U. S. G. S. locality 7095. Probably Benton, 

in the NW. ! SW. ! sec. 20, T. 11 N., R. 79 W., 

1 mile southwest of Dean's ranch, North Park, 

Colo. This is Beekly's locality 19, the type 

locality of L. 'oa.ga.ns. Narrow scales also occur. 

There is also a scale of Il olcolepis obliq11us. 

U. S. G. S. locality 7100. In the NW: i 

SE. ! sec. 8, T. 11 N., R. 81 W., northeast of 

the Hill ranch, North Park, Colo. Beekly's 

locality 26,2 said to be Niobrara but probably 

Benton. (Collected by A. L. Beekly and 

G. J. Finlay.) 'The scale is 8 millimeters in 

diameter and . is accompanied by a typical 

scale and one of Holcolepis. · 

U. S. G. S. locality 7110. Beekly'slocality 

37 (see above). 

The scales of Le~cichthyops certainly appear 

to indicate a primitive salmonid fish; the bones 

were probaBly delicate and rarely preserved. 

The scales show al certain resemblance, however, to those of Thyma.llus, though in that 

I u. s. GeQl. shrvey Bull. 596, p. 38, 1915. 

2 Idem, p. 42. 

genus the lateral line scales are much narr.ower 

and the median basal lobe is very large. It is, 

of course, possible that in · the Cretaceous the 

Salmonidae and Thymallidae were not differentiated. None of the European scales 

figured by Geinitz or Fritsch are of the Leucichthyops type. The scales of Aulolepis typus 

Agassiz, as figured by Woodward/ are curiously similar to those of Leucichthyops but 

wholly lack the radii in the apical field. 

Genus CYC!LOLEPIS Geinitz. 

The name Cyclolepis has been applied to 

subcircular or oval scales, with concentric 

circuli, nucleus centr2Ll or subGentral, and all 

radii and ctenoid elements wholly absent. 

This is, of course, the salmonid type of scale, 

excellently typified by the living Stenodus 

ma.ckenziei, from Alaska. Ca.ranx scales are 

very similar but have the circuli more or less 

distinctly angular at the sides. The scale 

which Fritsch erroneously calls Aspidolepis · 

steinlai Geinitz, from the. Cretaceous of Bohemia, has the shape t:md moderately eccent~ic 

nucleus exactly as in Stenodus . . A difficul~y 

in dealing with scales of this simple type is 

that uncharacteristic scales of quite different 

fishes may closely simulate them, .as shown by 

H. F. Taylor 4 in figures of essentially cycloid 

scales from the head of Cynoscion. Of course, 

the niore characteris1iic scales of the . same 

fishes would be almost sure to appear also in 

. the deposits: 

Cyclolepis stenodinus Cockerell, n. sp. 

Plate XXXV, figure 16. 

Scale oval, its greater diameter 12 milli- · 

meters; nucleus central (not eccentric as in 

Stenodus); circuli simple and concentric; rather 

strong growth lines, indicating possible migratory habits. Another scale, doubtless of 

the same species, is practically circular. 

U. S. G. S. locality 9190. Fox Hills sandstone, Greeley quadrangle, Colo. (Collected 

by T. E. Williard.) For details of the locality, 

see description of Hemilampronites hesperius 

(p. 185), which was found with it. The mollusk Callista nebrascensis Meek and Hayden 

was in the same material. 

a Woodward, A. S., The fossil fishes of the English chalk, pl. 19; 

figs. 3b, 4, 1903. 

«U.S. Bur. Fisheries Bull., vol. 34, pl. 52, 1914. 
182 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY,- 1918. 

Family ERYTHRINOLEPIDAE Cockerell, n. fam. 

Genus ERYTHRIN:OLEPIS Cockerell, n. gen. 

Scales rather small, subtriangular or subcircular, cycloid; basal margin slightly or riot 

crenate; circuli normal and concentric on basal 

half but excessively fine on apical half; radii 

apical, basal and lateral, but very irregular 

and often broken. The scales closely resemble 

those of the South American fresh-water 

Erythrininae but lack the coarse vertical circuli of the apical area. They may also be compared with the Old World Cyprinidae, and 

more remotely with the African fresh-water 

genus Phractolaemus. They also show some 

resemblance to Pantodon.1 

While I was puzzling over the scales, I received a paper by Eastman 2 in which it is set 

forth that the Cretaceous teeth of the genus 

Onchosaurus Gervais (Ischyrhiza Leidy; Gigantichthys Dames) agree very closely with those 

of the living fresh-water Hydrocyon and Hoplias, characoid genera. 3 It appeared to be a 

coi:rlirmation of Eastman's results that fish 

scales so similar to those of the Erythrininae 

(Hoplias, Hoplerythrinus, and Erythrinus) 

should occur in the Mowry shale. I wondered 

whether the Mowry could be a fresh-water deposit; and this suspicion seemed to receive 

some confirmation in the collection from U. S. 

G. S. locality 6603, in the Uinta Basin, Utah, 

assigned to the Mowry and including poorly 

preserved remains of land plants. This lot, 

however, included no Erythrinolepis scales. 

Mr. Stanton informed me that although Mollusca were rarely found in the Mowry, two 

localities on the southeastern border of the 

Big Horn Mountains had yielded ammonoids 

probably belonging to the genus Metoicoceras, 

and one of them yielded Inoceramus. These 

are clearly marine. One of these localities 

(4941) yielded also scales of Erythrinolepis, as 

well as those of Holcolepis. It must be said 

that the Mowry shale contains scales belonging 

to genera also present in undoubtedly marine 

1 Bioi. Bull., vol. 20, pl. 3, fig. 18, 1911. 

2 Eastman, C. R., Dentition of Hydrocyon and its supposed fossil allies: 

Am. Mus. Nat. Hist. Bull., vol. 37, pp. 757-760, 1917. 

a Dr. G. A. Boulenger, of the British Museum, writes me that he has 

read Dr. Eastman's paper and thinks his identification of Onchosaurus 

with the Characinidae highly probable. He adds: ''I shall be pleased if 

he is right, as I predicted the discovery of Upper Cretaceous characinids 

ill1905 CRept. Brit. Assoc.)." I thought it possible that Phractolaem'Us 

might be found to have similar teeth, but Dr. Boulenger informs me that 

the teeth of this genus do not show the characteristic base of Onchosaurus 

and Hydrocyon. 

Benton, and Erythrinolepis or a very closely 

related form occurs in the Chico. It can not 

be held, consequently, . that Erythrinolepis is· a 

fresh-water genus. It is also out of the question to consider Erythrinolepis to be the scales 

of Onchosaurus, for the latter belongs to a very 

much later period. 

The apical field of the Erythrinolepis scale 

appears in most specimens to be without any 

circuli, but in one good example (locality 4941, 

Big Horn Mountains) radiating excessively 

fine apical circuli can be seen, about four or five 

to one of the basal field. Laterally these circuli are nearly at right angles to the lateral 

ones, which are nearly vertical at this point. 

In the Erythrininae it is the apical series of circuli which is much coarser than the basal, and 

the lateral apical ones are continuous with the 

basal. We must suppose that Erythrinolepis 

represents a distinct family, Erythrinolepidae, 

though · it can not be adequately defined. 

Erythrinolepis rnowriensis Cockerell, n. sp. 

Plate XXXVI, figures 3-6. 

Scaies obtusely subtriangular, the base 

gently convex; radii basal, apical and lateral, 

very irregular, and often incomplete. , The 

type is about 5 millimeters in diameter. 

Type from U. S. G. S. locality 6713, southeast of camp at old chimney, Sisters Hill, Buf- • 

falo, Wyo., in Mowry shale. (Collected by 0. 

B. Hopkins.) Holcolepis transversus is from the 

same locality. 

Some other collections contain this species, 

as follows: 

U :S. G. S. locality 4896. North of Wolf Creek 

canyon, Big Horn Mountains, Wyo. (Collected by T. E. Williard.) Accompanied by 

Holcolepis and Leucichthyops. 

U. S. G. S. locality 4941. Abo11t 2! miles 

west of Klondike, Wyo. (Collected by T. E. 

WilliaTd.) With Holcolepis. The Erythrinolepis scale figured is 7 millimeters in diameter. 

These localities are all in the Mowry shale. 

Erythrinolepis chicoensis Cockerell, n. sp. 

Plate XXXVI, figures 1, 2. 

Very similar to E. mowriensis but nearly circular, a little broader than long, not subtriangular. The type is 11 millimeters in diameter; 

another is 10 millimeters. This is a larger 

species than E. mowriensis. 
SOME AMERICAN CRETACEOUS -F £SH SCALES. 183 

U.S. G. S. lodality 7030. Cretaceous, Chico 

group, south side of Ortigalito Creek, Cal., in 

Moreno formation. (Collected by Robert Anderson.) For 31dditional particulars see description of Pomolobus chicoensis . (p. 180). 

Family CTENOTHRISSIDAE. 

The remarkable genus Ctenothrissa, from the 

Cretaceous ofEJgland and Syria, has the pelvic 

fins enlarged arid far forward, and the type 

species was originally described by Pictet as a 

Beryx. Woodward pointed out the numerous 

differences from the berycoids and placed the 

fishes in a distinct family among the Isospondyli. It must be stated, however, that the 

scales of 0. radi4ns (Agassiz), which I am able 

to figure (Pl. XXXVII, fig. 1) through the kindness of Dr. Woo~ward, a:e extraordinarily like 

those of the I berycmd Hoploptetyx (Pl. 

XXXVII, fig. 2) ~ though the latter have coarser 

circuli. The scales also resemble those of Myripristis (Holocent!ridae), a living berycoid. The 

lateral circuli are vertical, not transverse, as in 

the clupeoids. ft seems probable, therefore, 

that Ctenothrissa represents a real advance in 

the direction o~the Percomorphi and should 

stand as the typ of a superfamily Ctenothrissoidea, of equ rank with the Clupeoidea 

(Clupeoidei) and Salmonoidea (Salmonoidei). 

I examined the scales of a -radians (Agassiz) 

and 0~ microcep~ala (Agassiz) in the. British 

Museum a number of years ago. The latter are , I 

remarkable for their width and are excellently 

figured by W oodrard in his work on the fishes 

of the English <yhalk, Plate XVIII, figure 9. 

Figure 8 of the safe plate, based on a scale from 

Reigate, Surrey, ~s evidently quite distinct. It 

is extremely broad, with about 12 basal radii 

arranged fanwis , and the apical margin bears 

long spinelike t~eth. . Except for the shape, 

this resembles tllte scales of the Gonorhynchidae.1 It may be designated Gonorhynchops 

{n. gen.) woodwdrdi n. sp., and may be separated from the ~onorhynchid Charitosomus by 

the shape of the ~cales. The latter genus, with 

elongate scales~·s known from the Cretaceous 

of Westphalia a d Syria. Aulolepis Agassiz, 

the other genus ascribed to the · Ctenothrissidae, has totally different cycloid scales. It 

occurs in the 'ronian of Sussex, Kent, and 

Surrey. The scdles resemble in a general way 

.J. Comoare Am. Mus. INat. Hist. Bull., vol. 3, pl. 4, fig. 4, 1890. 

those of the living berycoid Plectromus lugubris 

(Gilbert), froni Bering Sea, but the latter lack 

the strong concentric lines on the exposed portion. The large lateral line canal or ridge is 

also suggestive of the berycoids. 

Order INIOMI. 

Family ENCHODONTIDAE. 

Stewart recognizes a separate family, Stratodontidae, for Stratodus and Oimolichthys. 

Genus HALECODON Cockerell, n. gen. 

A genus of Enchodontidae related to Halec 

Agassiz is represented by the palatine and 

ectopterygoid,. the suture being between the 

tenth and eleventh tooth from end in type. 

The palatine resembles that of Halec but is 

more slender, with the teeth, except the-two 

apical ones, smaller. There are no long teeth 

like those of Enchodus. The ectopterygoid, 

compared with that of Halec, is much more 

elongated basally and bears on its apical half 

a great nun1ber of small teeth. The superior 

angle is above the basal end of the tooth row. 

Type H. denticulatus. 

Halecodon denticulatus Cockerell, n. sp. 

Plate XXXVI, figure 7. 

Length of the . combined bones about 54 

millimeters, the palatine slender and pointed 

at end. Teeth at end of palatine about 1.7 

millimeters long, sharply pointed; teeth on 

ectopterygoid about 1 millimeter long. 

U.S. G. S.locality 3_870. Cretaceous, Aspen 

shale, near Spring Valley, Wyo., in the SW. i 

SW. i sec. 24, T. 15 N., R. 118 W. (Collected 

by A. R. Schultz.) With it are various scales, 

including poorly preserved Ho?colepis, prob~ 

ably transversus. 

Halecodon is doubtless without scales but 

probably with some dermal scutes. A. S. 

Woodward 2 says of Halec: "A regular squamation of very small scales, the exposed area 

of each quadrangular in shape; no enlarged 

scutes." In a later work, however, 3 he states 

that no traces of scales have been observed in 

the species described, but enlarged dermal 

scutes occur on the tail. All reference to 

scales is omitted from the generic diagnosis, 

and thus llalec in this respect agrees with the 

2 Catalogue of fossil fishes in the British Museum, pt. 4, p. 212, 1901 • 

a The fossil fishes of the English chalk, p. 55, 1902. 
184 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

other Enchodontidae. No doubt Halecodon 

has similar features. 

Genus CIMOLICHTHYS Leidy. 

The American forms from the Niobrara of 

Kansas, described under five names by Cope, 

are now ponsidered to rep resent a single 

species, 0. nepaholica (Cope). A specimen 

(Colorado Univ. Mus. 5388) collected by Prof. 

Mead in the Benton (Cretaceous) west of 

Laramie, Wyo., represents the top of the head 

and agrees excellently with this genus. The 

skull was a trifle smaller and somewhat narrower than that of 0. lewesiensis Leidy, and 

also narrower than the American 0. nepaholica. 

No doubt a distinct species is in.dicated, but 

more material is desirable. It is not certain 

that Stratodus can be distinguished from 

Oimolichthys by the parts here preserved. 

Genus ENCHODUS Agassiz. 

Enchodus sp. 

Plate XXXVI, figure 9. 

The operculum of a species of Enchodus was 

discovered in the Colorado shale of the Milk 

River coal field, ¥ont. U. S. G. S. locality 

6187, in sec. 3, T. 29 N., R. 19 E., in black~hale 

south of Miller's No.1 ranch. (Collected by L. 

J. Pepperberg.) Numerous species are known 

from the Niobrara of Kansas. 

Family TOMOGNATHIDAE. 

The only known representative of the Tomognathidae, Tomognathus mordax Dixon, is 

founded on fragments from the chalk of Kent, 

Sussex, anQ Surrey. It. is said to suggest 

affinity with the deep-sea Stomiatidae. No 

scales are mentioned in the description, and 

there presumably were none, as in the living 

forms supposed to be related. · 

Family MYCTOPHIDAE. 

The family Myctophidae has been made a 

depositary for miscellaneous more or less obscure genera. Ichthyotringa Cope, from the 

Niobrara of South Dakota, has been referred 

to Rhinellus Agassiz, a genus of the Westphalian and Syrian Cretaceous. Hay considers 

the genus to belong to the Dercetidae (Heteromi), but it has been regarded as the type of a 

distinct family, Rhinellidae, though Dr. D. S. 

Jordan (in letter) doubts the validity of this 

course. Four species of Sardinius or Leptosomus, small fishes with (at least in two of them) 

cycloid scales, are described from the Niobrara 

of South Dakota. I can add nothing to Hay's 

account. Osmeroides illustrans (Woodward), 

described under Sardinioides, from the chalk 

of Kent, shows affinity with the Aulopidae. 

Family NOTACANTHlDAE. 

Pronotacanthus Woodward is from the Cretaceous of Mount Lebanon, Syria. No scales 

can be distinguished. The modern representatives of the family are described as having 

very small cycloid scales. 

Order APODES. 

Family ANGUILLA VIDAE. 

Anguillavus Hay, from the Cretaceous of 

Mount Lebanon,; retains the pelvic fins. The 

scales are said to be rudimentary· or absent. 

Family URENCHEL YIDAE. 

Urenchelys Woodward, from the Cretaceous 

of Mount Lebanon, differs from Tertiary and 

living eels by having a distinct caudal fin. 

The scales are described as ''rudimentary." 

A species provisionally referred to the same 

genus occurs in the Turonian of Sussex and 

Kent. • Family ENCHELIIDAE. 

Enchelion Hay, from Mount Lebanon, has 

no scales. 

Order HETEROMI. 

Family HALOSAURIDAE. 

Genus ECHIDNOCEPHALUS Von der Mar.ck. 

Echidnocephalus? americanus Cockerell, n. sp. 

Plate XXXVI, figure 10. 

Scale subquadrat~, longer than broad, 3 

millimeters wide; rmcleus subapic.al; apical 

margin not ctenoid but ragged and .free from 

circuli (exactly as in living Halosaurus); circuli_ 

very distinct, ·the lateral ones paralle~ with. 

margin; nine basal radii, very distinct, _arranged 

fan wise; lower margin deeply crenate. 

U. S. G. S. locality 5138. Br~ckish-water-_ 

beds of Mesaverde formation, about 26 miles. 

northeast of Rock Springs, Wyo., in sec. 15,. 

T. 21 N., R. 103 W. (Collected by V. H. 

Barnett.) The character of the :fish suggests. 

marine conditions. The scale agrees 'excellently with the modern HaJosauridae, such as 

Halosaurus and Aldrovandia, differing only in_ 
SOME AMERICAN CRETACEOUS F ISH SCALES. 185 

the more ordinary rounded nuclear area, which 

is elongated in the living fishes. 

Echidnocephalus, from the Upper Cretaceous 

of Westphalia, is said to be essentially identical 

with Halosaurus, so I refer the scale provisionally to that genus. 

Echidnocepi alus? pacificus Cockerell, n. sp. 

Pif1te XXXVI, figure 11. 

Scale 6_ millilrneters wide, cycloid, subquadrate, rounded J apically; sides rather convex ; 

1aterohasal col ners very obtuse, not salient ; 

nucleus just below the apex; six basal radii, 

.rather widely paced, arranged fan wise; basal 

. margin shallo'flY crenate. This is more like 

Halosaurus, wlhereas E.? - americanus is like 

Aldrovandia, the very apical nucleus and ab-

:sence of deep b/asal crenation being Halosaurus 

-characters. 

The extrem ly apical nucleus also occurs in 

.Bathysaurus agassizi, which, however, has sub-

-circular scal::lwithout a trace of radii. 

U.S. G. S.l cality 7027. Cretaceous, Chico 

group, foot · , between Little Panoche and 

Ortigalito creeks, Cal., in first canyon south of 

.Laguna Seca ~eek, in limy layer between lower 

_gray sandston and fossiliferous grit bed in 

·upper part of Moreno formation. (Collected 

-by Robert An erson.) 

I 

Family DERCETIDAE. 

A. S. Woo~ward says of the Dercetidae: 

·"Ordinary sca[es small or wanting, but two or 

·more continuf

1 

us paired series of enlarged 

;scu tes along fl nks ; no m_ edian dorsal or ventral 

:scutes." The scales are more or less triangu1ar, the outline resemb]ing that of shark teeth 

(Isurus). ThJ type of Dercetis is D. scutalus 

Agassiz, ~rom/ the Cretaceous of Westphalia. 

According to Woodward these fishes are appar-

·ently allied t9 the Halosauridae and N otacanthidae. If so, hey should be placed in the order 

Heteromi. Lbptotrachelus longipinnis Cope, 

Teferred to ~~ Dercetidae, occurs in the Niobrara of SoutH Dakota. Triaenaspis virgulatus 

··Cope, also fro ~ the Niobrara of South Dakot a, 

is referred by fYoodward to Leptotrachelus, but 

Hay states that the genus Triaenaspis is valid. 

Leptotrachelus/ also occurs in t~e Upper e­ -taceous of Ef gland, Westphaha, and Syr1a. 

.Boulenger refers the Dercetidae to the Heteromi. 

I 

Order HAPLOMI. 

Family CROSSOGNATHIDAE. 

Orossognathus Pictet, from the N eocomian of 

Switzerland and Hanover, is said to have the 

scales large, very deeply overlapping, smooth, 

and not serrated or crenulated on posterior 

margin; a simple tube pierces the lateral line 

scales. Syllaemus Cope was formerly referred 

to this family, but Woodward now considers it 

a primitive clupeoid. It has not the transverse cireuli-of the scales of Clupeidae. 

Apsopelix and Pelecorapis of Cope have been 

listed under Crossoghathidae; Hay placed the 

first doubtfully in Albulidae, the second in 

Mugillidae . 

A psopelix sauriformis Cope came from Bunker Hill station on the Union Pacific Railroad 

of Kansas. Mr. T. W. Stanton te]Js me that 

this is certainly in the Benton. Cope says that 

the scales are ''large and cycloid. They do not 

present j1 trace of radii but are marked with 

fine and close concentric grooves [circuli]; these 

assume a vertical direction on the exposed surface, and are there moreirregular, the more marginal ones terminating above and below. But 

few (i. e., the central) grooves are truly 

circular.'' 

Order SYNENTOGNATHI. 

Family HEMmAMPHIDAE. 

Genus HEMILAMPRONITES Steinla. 

The generic name Hemilampronites was published by Geinitz from Steinla's manuscript for 

certain scales found in the Turonian of Saxony. 

The speeies was called H. steinlai Geinitz. As 

a matter of fact the scales agree well enough 

with Hyporhamphus and would be referred to 

that genus without question were they not 

from the Cretaceous. 

Hemilampronites hesperius Cockerell, n. sp. -

Plate XXXVI, figure 13. 

Scale 12 millimeters in diameter, broader 

than long, cycloid, w1thout radii _ (Hyporhamphus has a few); circuli of apical field ~xtremely fine and regular, extending across 

scale; the other circuli much coarser and 

widely spaced at sides, where they pass transversely and more or less obliquely (especially 

above) to the margin, the upper nearly at right 

angles with the fine circuli of the apical field. 
186 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Differs from H. steinlai by the absence of basal 

radii and the oblique upper lateral circuli. 

U.S. G. S.locality9190. Cretaceous, Fox Hills 

sandstone, Greeley quadrangle, Colo., in second 

large ravine 2! miles south of Milliken and 

half a mile west of railroad track near Wildcat Mound, in sec. 23, T. 4 N., R. 67 W. (Collected by T. E. Williard.) 

A related fish (Hemiramphus edwardsi Bassani) has been found in the upper Eocene near 

Verona. Regan suggests that Oobitopsisfrom the 

lower Oligocene of France, referred by Woodward to the Ammodytidae, may belong to the 

same group as the fishes now discussed, in the 

immediate vicinity of Ohriodorus, if indeed distinct from that genus. No scales were found 

on the fossil Oobitopsis. Ammodytid scales 1 are 

very unlike those of the Hemiramphidae. 

Order PERCOMORPHI. 

Suborder BERYCOIDEI. 

Family PLATYCORMIDAE 1ordan (in letter). 

Platycormus Von der Marek; from the Cretaceous of Westphalia, is described by Woodward as having the scales ctenoid, of moderate 

size, more or less ornamented with granulations, and extending over the opercular apparatus, head, and base of median fins. There are 

no enlarged or thickened scales. This genus, 

along with Omosoma Costa, from Mount Lebanon, and Berycopsis Dixon, has been provisionally regarded as belonging to the Stromateidae. It is also to be noted that the Cretaceous scales figured by Geinitz in the work 

already cited (especially his fig. 3; fig. 4 may 

be latinucleate) as Aspidolepis steinlai agree 

with those ofthe Stromateidae (Poronotus). 

Family BERYCOPSIDAE Jordan (in letter). 

Berycopsis Dixon is represented by three 

species in the English chalk. At the British 

Museum I examined the large broad scales of 

B. major Woodward, from the Middle Chalk of 

Cuxton, Kent. They are about 25 millimeters 

broad, with fine grooving toward the apex; 

they are not strictly ctenoid. These scales are 

extremely like those of Hoplopteryx lewesiensis. Berycopsis elegans Dixon, the type o~ 

the genu!?, has much smaller scales, and it 

seemed to me hardly possible that it could be 

congeneric with B. major. Woodward states, 

l See Gill, Theodore, U.S. Nat. Mus. Proc., vol. 28, p. 162, 1904. 

however, that the structural char.acters of the 

two are about the same. B. pulchellus (Dixon) 

is allied to B. major. 

Family HOPLOPTERYGIDAE Cockerell, n. fam. 

I 

Based on Hoplopteryx Agassiz. Resembling 

the Trachichthyidae, but anal spines four, as in 

Berycidae; scales as in Holocentridae. Dorsal 

fin without the notch or· division of the 

Holocentridae, and its spines much fewer (six). 

Anal fin very much shorter than in Beryx, but 

dorsal longer. Although the scales of Hoplopteryx resemble those of Berycopsis, the fish 

is very different in a number of characters and 

can not be very closely related. Both anal and 

dorsal fins of Berycopsis are extremely long. 

Beryx insculptus Cope, from the Cretaceous of 

New Jersey, is vety imperfectly known, but 

the scales agree with Hoplopteryx and not with 

Beryx. It may be provisionally called Hoplopteryx ? insculptus. 

The berycoid fishes were certainly well 

developed in Cretaceous time, and to-day weseem to have only remnants of a once morenumerous group. The modern families, for· 

scales of which I am indebted to Dr. D. S. 

Jordan, the United States National Museumr 

the United States Bureau of Fisheries, and theMuseum of Comparative Zoology, have thefollowing scale characters: 

Polymixiidae: Polymixia japonica Steindachner has very broad scales, with strongly 

crenulated lower margin, and the apical margin 

strongly, irregularly dentate. It differs from 

the Holocentridae at once in the broad fanlike 

basal undulations rather than distinct radii, 

though it is approached in this· by Ostichthys. 

It differ~ from Ostichthys by the much smaller, 

irregular teeth, and radically in the widely 

spaced circuli, the lateral ones oblique and 

entering the margin. In Ostichthys the circuli 

are excessively fine (though the scale is much 

larger), and the lateral ones are vertical. I 

know of no Cretaceous scale like that of Polymixia~ 

Holocentridae: The holocentrid scale seems 

to be the ancient one of the group, to judge: 

from the fossils, though the fins of the modern. 

family are much modified. The very strong, 

widely spaced apical keels terminating in.. 

teeth, so well shown in the scale figured by 

Geinitz and quite wrongly atrtibuted to Macrol!oma mantelli, appear (even more widely 
SOME AMERICAN CRETACEOUS FISH SCALES. 187 

I 

spaced) in the livling Ostichthys pillwaxi, from 

the Hawaiian Islands (Pl. XXXVI, fig. 8). 

Myripristis scales! differ from those of Ostichthys by the much' closer teeth, about three to 

one. Flammeo sqales are not nearly as broad 

as those of the genera just mentioned, and the 

basal margin has a distinct median prominence, sometimes 1 broken up into several little 

ones in F. scythrops. Holocentrus scales are 

broad, usually ~th several radii close together in the mid le of the base.1 The apical 

teeth · are like t~ose of a coarse comb, not 

keeled as in Ostickthys and the Geinitz scale. 

Berycidae: Scales of Beryx splendens Lowe 

are cycloid, withl the broad hyaline marginal 

area beset with small tubercles or spines. In 

other species, as B. lineatus, the marginal area 

is beset with Ion~ spines, the most apical projecting beyond the margin. Basal radii are 

feeble or absent. The structure of the apical 

field is thus diff rent in the Berycidae from 

that of the Ho ocentridae. In the former 

there are spines s<tattered over a surface, in the 

latter strong ridg1es or apical teeth. The true 

berycid type apparently does not appear 

among the Cretaceous fossils. 

Trachichthyid e: Trachichthys au~tralis has 

the broad and ~~ry dense scales constructed 

after the type of the Berycidae, the apical 

field being densel} spinose. Dr. Jordan kindly 

sends me scales 9f two other genera, which he 

formerly placed fith the Berycidae but has 

more recently referred to the Trachichthyidae. 

They are utterly I diverse from each other and 

from the other/ berycoids here discussed. 

Plectromus lugubr(is (Gilbert), from the vicinity 

of Bogoslof Island, Bering Sea, has subquadrate cycloid scales, with widely spaced circuli, 

and three or four basal radii arranged fanwise. Oaulolepis longidens, from deep water 

off Hawaii, has v ry small roundish scales, with 

four or five very widely spaced spinelike marginal projections. 

Monocen tridae: M onocentris japonicus has 

the sca.les with a !high central keel or crest, but 

otherwise it is of the Trachichthys type, with 

spinose apical field. 

We must evidJrtly consider that the modern 

berycoids are va iously specialized descendants 

of the Cretaceous forms, none of them retaining the same co~binations of characters. The 

1 See U.S. Bur. isheries Bull. for 1912, pl. 36, fig. 26. 

precise arrangement of the Cretaceous genera 

for the present remains uncertain. Woodward 

figures the seales of the English Cretaceous 

Homonotus Dixon and Trachichthyoides Woodward. Both have scales of the holocentrid 

type, not of the berycid-trachichthyid type. 

The opercular apparatus of Trachichthyoides 

readily separates it from Hoplopteryx. Some 

of the genera, as Dinopteryx Woodward, from 

Mount Lebanon, have cycloid scales. 

The total absence of berycoids from the interior region of the United States has seemed 

remarkable. · The Cretaceous scales from the 

Rocky Mountain region that 1 I have examined 

do not include any undoubted berycoids, 

though a few poorly preserved specimens, 

which I have not ventured to describe, might 

conceivably be aberrant berycoids. Cope's 

genus Pelecorapis is of uncertain affinities. 

The scales of P. berycinus Cope, as figured by 

him, closely resemble those of Hoplopteryx? insculptus (Cope). The type of the genus is, 

however, P. varius Cope, found in Kansas, 

almost certainly in the Benton. It is said to 

have abdorninal ventral fins, and to be related 

in a genera] way to the Scombresocidae, Atherinidae, etc. It can not well belong to the 

berycoids, nor does Cope's account of the 

scales suggest such a reference. The second 

species, P. berycinus, is of very doubtful 

generic position. It is equally uncertain as to 

locality and age, and may very well not be 

from Montana, as Mr. Stanton informs me. 

We are thus still left without berycoids in the 

Cretaceous mediterranean sea_ of America. 

Order ACANTHOPTERI. 

It is possible that the Stromateidae existed in 

Cretaceous time. The scale of Aspidolepis 

stei:nlai Geinitz, from the Turonian of Saxony, 

certainly resembles that of the living Poronotus. 

It is cycloid, with the lateral circuli more or 

less angled. Omosoma Costa, from Mount 

Lebanon, has been provisionally referred here. 

Woodward describes the scales as small, 

smooth, and cycloid, apparently longer than 

deep, extending over the opercular apparatus, 

head, and base of anal and dorsal fins. Woodward 2 rmnarks that the Cretaceous fishes 

which he provisionally assigned to the Stromateidae a,re primitive scombroids of uncertain 

2 The fossil fishes of ~he English chalk, p. 5, 1902. 
188 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

affinities. It must be said that the stromateid 

scale of to-day is very similar to that of the 

scombroids; and it is thus easy to suppose that 

the Cretaceous fishes were rather of the latter 

than the former group. 

Carangidae are reeorded from the Cretaceous 

of Europe and Syria., the prineipal genus being 

Aip~chthys Steindachner, · with small, thin, 

cyc.~loid scales and a series of ventral ridge 

scales on the short abdominal region before 

the dorsal fin. Bathysoma lutlceni Davis, from 

the Danian of Scandinavia, said by Woodward 1 to be "very curiously specialized." 

Prolates Priem, with "scales small and very 

finely serrated," is from the Upper Cretaceous 

of France and has been referred to the Percidae. So far as I know, the typical percoid 

scale does not appear in the Cretaceous, but 

is first found near the base of the Tertiary, in 

a fresh-wat~r deposit, as described below. 

Family CENTRARCHIDAE. 

Genus CENTRARCHITES Cockerell, n. gen. 

Fresh-water fishes with scales agreeing with 

Centrarcl;lidae or Micropteridae but not defi1 The fossil fishes of the English chalk, p. 253, 1912. 

nitely assignable to a known genus. Type 

0. coloradensis. 

Centrarchites coloradensis Cockerell, n. sp. 

Plate XXXVI, figure 12. 

Scale subquadrate, transverse diameter 9 

millimeters; apical margin not distinctly dentate, · but apical field with a broadly trian~lar 

ctenoid patch, as in the young of Amblopl~tes; 

nucleus far apical of middle, just below .lower 

end of ctenoid patch, the surrounding circuli 

transversely oval (more so than in modern 

genus); basal radii occupying abou~ middle 

third (transversely) of scale, about nme, close 

together, with very fine transverse circuli between; lateral circuli parallel with margin. 

U. S. G. S. locality 7087. Eocene, c_oalmont formation, .about 1 mile southwest of 

Walden, Colo. (Collected by A. L. Beekly.) 

This is Beekly's locality 1.2 With it is a fragment of a Vimparus and a fragment of a Laurus-like leaf. There is also another species of 

fish scale, nearly circular, with very fine circuli, possibly salmonoid~ 

s u.S. Geol. Survey Bull. 596, p. 63, 1915. 
• 

PLATE· XXXI . . · · 

28288°-- 9----13 189 
• 

PLATE XXXI. 

FIGURE 1. Petalolepis? fibrillatus eockerell (p.172). Type, X 6. u. s. G. s. locality 5094. u. s. N. M. catalogue 

No. 8662. 

2. Cycloides? incertus Cockerell (p.l73). Type, X 3. U.S. G. S.locality 5177. U.S. N.M. catalogue No. 8663. 

3, 4. Holcolepis pulchellus Cockerell (p. 17 4) : 

3. Type, X 8. U. S. G. S. locality 7110. U.S.N. M. catalogue No. 8664. 

4. Another specimen, X 6. U. S. G. S. locality 7108. U.S.N. M. catalogue No. 8665. 

5. Holcolepis delicatus Cockerell (p. 175). Type, X 4. U.S. G. S. locality 8916. U.S.N. M. catalogue No. 

8666. ' 

6-13. Holcolepis transversus Cockerell (p. 175): 

6. Type, X 4. U. S. G. S. locality 6682. U.S.N. M. catalogue No. 8667. 

7. X 3. U.S. G. S. locality 6681. U.S.N. M. catalogue No. 8668. 

8. X 3. U.S. G. S. locality 6713. U.S.N. M. catalogue No. 8669. 

9. X 4. U. S. G. S. locality 6682. U. S. N. M. catalogue No. 8670. 

10. X 4. U. S. G. S. locality 6713. U. S. N. M. catalogue No. 8671. 

11. X 4. - U.S. -G. S.locality 3417. U.S.N. M. catalogue No. 8672. 

12. X 4. U.S. G. S. locality 6682. U.S.N. M. catalogue No. 8673. 

13. X 3. U.S. G. S. locality 4421. U.S.N. M. catalogue No. 8674. 

190 
U. S, GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXXI 

2 

4 5 

3 

6 7 

10 

8 

9 

11 12 13 

CRETACEOUS, FISH SCALES 

• 

• 

\ 

• 

. PLATE XXXII. 

• 

191 

• 
• 

• 

I 

• PLATE XXXII. 

FIGURE 1. Holcolepis obliquus Cockerell (p. 175). Type, X 3. U.S. G. S.locality 4421. U.S.N. M. catalogue No. 

8675. 

2. Holcolepisf mandible, X 2 (p. 175). Carbon County, Wyo. U.S.N. M. catalogue No. 8676. 

3. Pachyrhizodus scale from Cretaceous of England. After Woodward, Geol. Assoc. Proc., vol. 10, pl. 1, fig. 8, 

1888 (p. 174). 

4. Helmintholepis vermiculatus Cockerell (p. 176). -Type, X 3. U.S. G. S.locality 9184. U.S.N. M. catalogue 

No. 8677. 

5. Hypsodont granulosus Cockerell (p. 178). Type, X 4. U.S. G. S. locality 4874. U.S. N .M .catalogue No. 

8678. 

6,;. Hyposodonf radiatulus Cockerell (p. 178): 

6. Type, X 3. U. S. G. S. locality 5177, U.S.N. M. catalogue No. 8679. 

7. Latinucleate scale, X 3. U.S. G. S. locality 5174. U.S.N. M. catalogue No. 8680. 

8. Hypsodon audax (Leidy). Scale, X 2 (p.177). U.S. G. S.l'Jcality 8354. U.S.N. M. catalogue No. 8681. 

192 . 

• 
U. S. GEOLOGICAL SURVEY 

6 

7 

PROFESSIONAL PAPER 120 PLATE XXXII 

2 

8 

CRETACEOUS FISH SCALES 

3 

PLATE XXXIII. 

193 

• 
PLATE XXXIII. 

FIGURES 1, 2. Hypsodon audax (Leidy) (p. 177): 

1. Specimen showing several scales and parts of skeleton. University of Kansas collection. 

2. Part of same specimen, more enlarged. 

194 

• 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXXIII 

2 

CRETACEOUS FISH SCALES 
• 

• 

PLATE XXXIV . 

• 

195 

• 
PLATE XXXIV. 

FIGURE l. Chicolepis punctatus Cockerell (p. 177). Type, X 3. U.S. G. S.locality 7030. U.S.N. M. catalogue No. 

• 86~2. • 

2. Hypsodon lowii (Stewart) Cockerell (p. 178). Scale, X 2. U.S. G. S.locality 7294. U.S.N. M. catalogue 

No. 8683. 

3. Ichthyodectes sp. (p. 179). Lateral line scale, X 4. U. S. G. S. locality 2402. U. S. N. M. catalogue No. 

8684. 

4. Ichthyodectessp. (p.179). Lateral line scale, X 4. U.S. G. S.locality 7277. U.S.N. M. catalogue No. 8685. 

5. Pomolobus? chicoensis Cockerell (p. 180). Type, X 10. U. S. G. S. locality 7030. U.S.N. M. catalogue 

No. 8686. ;' 

6-12. Cretaceous fish scales from Turkestan (p. 179). Copied fr~m ·G. D. Romanowsky, Materialui dlya geologii 

Turkestanskago kraya, pts. 2, 3, 1884, 1890. 

6-8. Hypsodon sp. Figured as Cladocyclus strehlensis Geinitz. Op. cit., pt. 3, pl. 17, figs. 6a-c. 

9. Hypsodon? sp. Figured as Osmeroides lewesiensis (variety). Idew., pt. 2, pl. 23, fig. 4a. 

10. Ichthyodectes sp. Figured as Cladocyclus strehlensis. Idem, pt. 2, pl. 23, fig. 4b. 

11. Ichthyodectes? pectinolepis. Figured as Osmeroides pectinolepis Romanowsky. Idem, pt. 3, pl. 17, 

fig. 5 . . 12. Undetermined scale. Figured as Beryx sp. .Idem, pt. 3, pl. 17, :fig. 4 .. 

. l3. Fragment of Mowry shale, X 2, showing scales of Erythrinolepis mowriensis, Leucichthyops vagans, and 

Holcolepis transversus (pp. 182, 180, 175). U. S. G. S. locality 4896, north of Wolf Creek canyon, Big 

Horn Mountains, Wyo. U. S. N. M. catalogue No. 8687. 

196 

• 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXXIV 

2 

3 

4 

5 

9 

6 

7 

11 

12 

13 

CRETACEOUS FISH SCALES 

. I 

I . 

I 

. I·. ·.. . . 

PLATE .XXXV. _ · ; .... 

, \ 

197 
PLATE XXXV. 

FIGURES f-15. Leu'cichthyops vagam Cockerell (p. 180): 

1. Type, X 4. U.S. G. S. locality 7095. U.S.N. M. catalogue No. 8688. 

2, 3. Two scales, X 3. Carbon County, Wyo. U.S.N. M. catalogue Nos. 8689, 8690. 

4. Scale, X 4. Black Hills, S. Dak. U.S.N. M. catalogue No. 8691. 

5. Scale, X 3. U.S. G. S. locality 3880. U.S.N. M. catalogue No. 8692. 

6. Scale, X 3. U.S. G. S. locality 7275. U.S.N. M. catalogue No. 8693. 

7. Narrow scale, X 3. U. S. G. S. locality 6681. U.S.N. M. catalogue No. 8694. 

8. Scale, X 4. U.S. G. S. locality 8916. U.S.N. M. catalogue No. 8695. 

9. Narrow scale, X 4. U. S. G. S. locality 7110. U.S.N. M. catalogue No. 8696. 

10. Laterallinescale, X 4. U.S. G. S. locality 6682. U.S.N. M. catalogue No. 8697. 

11. Laterallinescale, X 4. U .. S. G. S.locality 7095. U.S.N. M. catalogue No. 8698. 

12. Laterallinescale, X 4. U.S. G. S.locality 7110.· U.S.N. M. catalogue No. 8699. 

13. Laterallinescale, X 4. U.S. G. S. locality 7100. U.S.N. M. catalogue No. 8700. 

14. Laterallinescale, X 4. U.S. G. S. loc::riity 7110. U.S.N. M. catalogue No. 8701. 

15. Latinucleate scale, X 4. Black Hills, S.Dak. U.S.N. M. catalogue No. 8702. 

16. Cyclolepis stenodinus Cockerell (p. 181). Type, X 4. U. S. G. S. locality 9190. U. S. N. M. cata~ 

logue No. 8703. 

198 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXXV 

4 

6 

8 

10 

7 

13 

14 15 16 

CRETAC,OUS FISH SCALES 

• 

PLATE XXXVI. 

199 
' 

• 

PLATE XXXVI. 

i'IGURES 1, 2. Erythrirwlepis chicoensis Cockerell (p. 182): 

1. Type, X 4. U.S. G. S.locality 7030. U. S. N. M. catalogue No. 8704. 

2. Smaller scale, X 4. U. S. G. S. locality 7030. U. S. N. M. catalogue No. 8705. 

3-6. Erythrirwlepis rrwwrienSis Cockerell (p. 182): 

3. Type, X 4. U. S. G. S. locality 6713. 

4. Scale, X 4. U. S. G. S. locality 6713. 

5. Scale, X 4. U. S. G. S. locality 6713. 3-5, U. S. N. M. catalogue No. 8706. 

6. Scale, X 4. U. S. G. S. locality 4941. U. S. N. M. catalogue No. 8707. 

7. Halecodon denticulatus Cockerell (p.183). Type. Palatine and ectopterygoid, X 1.5. U.S. G. S.locnJity 

3870. U.S.N. M. catalogue No. 8708. 

8. Ostichthys pillwaxi (p. 187). Apical region of scale, X 1.85. Honolulu market. 

9. Enchodus sp. (p. 184). Operculum, X 2. U.S. G. S. locality 6187. U.S.N. M. catalogue No. 8709. 

10. Echidrwcephalus? americanus Cockerell (p. 184). Type, X 8. U. S. G. S. locality 5138. U. S. N. M. 

catalogue No. 8710. 

11. Echidrwcephalus? pi:uificus Cockerell (p. 185).. Type, X 4. U.S. G. S. locality 7027. U.S.N. M. catalogue No. 8711. 

12. Centrarchites coloradensis Cockerell (p. 188). Type, X 4. Eocene. U. S. G. S. locality 7087. 

U.S.N. M. catalogue No. 8712. 

13. Hemilampronites hesperius Cockerell (p. 185). Type, X 6. U. S. G. S. locality 9190. U. S. N. M. 

catalogue No. 8713. 

14. Latinucleate (regenerated) scale of undescribed species, with marginal teeth resembling those of the 

berycoids, X 3. U. S. G. S. locality 4867. Cretaceous, Mowry shale, sec. 1, T, 26 N., R. 88 W., 

near North Rawlins, Wyo. U. S. N. M. catalogue No. 8714. 

15. Scale of undescribed species with marginal teeth suggesting the berycoids, X 10. U. S. G. S. locality 

4426. Cretaceous, Mowry shale, SE. t sec. 27, T. 33 N., R. 74 W., about 5 miles southwest of Careyhurst, Wyo. U. S. N. M. catalogue No. 8715. 

16. Scale of undescribed species, X 10. U. S. G. S. locality 6603, SE. t sec. 18, T. 1 S., R. 10 W., Uinta 

special base line, Utah. Said to be Mowry shale. The collection contains plant remains and may 

be from a fresh-water deposit. U. S. N. M. catalogue No. 8716. · 

17. Scale of undescribed species, perhaps clupeid, with fine transverse circuli, X 4. Transverse diameter 

12.5 millimeters. From the same station as figure 16. Presumably fresh water. U. S. N. M. catalogue No. 8717. 

200 
U. S. GEOLOGICAL SUR VRY PROFESSIONAL PAPER 120 PLATE XXXVI 

4 

5 

grrrnttfth111l1J 

8 

7 

10 11 12 

14 

15 16 17 

CRETACEOUS FISH SCALES 

• 

PLATE XXXV-II. 

201 

• 
• 

PLATE XXXVIi. 

FIGURE 1. Ctenothrissa radians (Agassiz) (p. 183). Cretaceous of England. From a specimen in the British Museum. 

2. Hoplopteryx lewesiensis (Mantell) (p. 183). Oretaceous of England. From a specimen in the British 

Museum. 

202 

• 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 120 PLATE XXXVII 

2 

CRETACEOUS FISH SCALES