Palæontological Report of the Princeton Scientific Expedition of 1877

Uintatherium princeps, sp. nov.

Established on several portions of the head, vertebral column, and the limbs.

This species may readily be distinguished from the last by its larger size, the broad nasals with small tuberosities, the stronger zygomatic arches, and the sub-cylindrical centra of the dorsal vertebræ.

The nasals are broad and flat for some distance behind the tuberosities. Although the animal was not adult, the nasal suture is almost obliterated, and is visible only on the inferior surface; in this respect it is very different from the U. leidianum, in which the suture persists throughout life; as is shown by the type specimen, which was past maturity. The tuberosities of U. princeps are lower, broader, and more everted than in the preceding species; are not divided by a groove, but united together by a low rounded ridge, to which the surface of the nasals gradually rises from behind. The portion of the bones anterior is short, stout, and projects horizontally.

The median, or maxillary, projections are apparently short and everted; they are somewhat compressed antero-posteriorly, and enlarge rapidly downwards. They are transversely oval in section.

The posterior, or parietal, projections are different from any that we have yet seen. They are subtrihedral at base and flattened antero-posteriorly above. The upper margin is regularly arched, and is the thinnest portion of the process. The posterior face is perfectly flat, and the parietal crest makes a sharp angle with it, rising lower down than in U. leidianum; the frontal crest is also lower down than in that species, and the anterior face is strongly convex. The internal margin is rounded and straight, and does not show the longitudinal groove marked in the last species.

The frontal has the eminences and depressions common to the members of the genus; but the superciliary ridge is unusually sharp and sinuous in outline.

The squamosal is short, stout, and high; is but slightly curved outwards, but apparently projects somewhat downwards. The malar articulation is broad and flat, indicating the heaviness of that bone. As a whole the zygomatic arch is stronger, and probably shorter, than in U. leidianum.

The occipital condyles are proportionately rather small; they are placed on a long neck and project downwards. They are strongly convex from above downwards, but scarcely at all so from side to side. The internal border is slightly emarginate.

The dorsal vertebræ are of about the same proportionate length as in U. leidianum, but are higher and wider; and the centra are subcircular in section, slightly contracted in the middle. The costal surfaces are wide and deep, and vertically oval in shape; they are placed partly on the centra and partly on the neurapophyses. The transverse processes are short, stout, and tuberous, and raised high above the centrum. There is a deep notch at the posterior edge of this process, at its junction with the neurapophysis. The neurapophyses are trihedral, somewhat low, and very stout, forming a wide neural canal.

The ulna (Plate VII. Fig. 2) is thick, with a long and rugose olecranon. The shaft is long and stout; it shows a distinct medullary cavity. The distal end is small, and shows a low, heavy, styloid process.

A metacarpal resembles the corresponding bone in Dinoceras, but is rounder and less rugose. There are two faces for carpal articulations, which meet at an open angle.

Measurements.

Found at Henry's Fork.

Uintatherium robustum. Leidy.

Cont. to Ext. Vert. Faun., p. 96.

A fragmentary skeleton from Henry's Fork.

RODENTIA.

PARAMYS, Leidy.

"Extinct Vertebrate Fauna of the Western Territories," vol. i. Hayden's Surveys, p. 109 et seq.

This genus of the gnawers is very closely allied to the squirrels and marmots. Dr. Leidy sums up the generic characteristics of the teeth thus:

"The four lower molars are proportionately narrower than in squirrels and marmots, the fore-and-aft exceeding the transverse. The crowns are short, square, tuberculate, and enamelled.

"The lower jaw is proportionately shorter and deeper than in most known rodents; the reduction in length being mainly due to a less development of that part of the bone in advance of the molars. To compensate for the difference in length, and to make room to accommodate the incisors, these teeth reach further back than usual.

"The acute edge of the hiatus between the molars and incisors is almost on a level with the alveoli, of the teeth, instead of forming a deep concave notch, so conspicuous a feature in the jaws of the gnawers generally."

Species known.—

Am. Journ. Sc. v. iv., p. 218.

Paramys superbus, sp. nov.

Established on a single lower incisor.

The species indicated by this specimen is the largest of the genus as yet known. The tooth is subtrihedral in section, is stout, and shows but little curvature. The anterior and lateral faces are broad, and the under margin to which the sides converge, is narrow. The enamel is thick and is inflected so as to cover a small portion of the sides as well as the front.

Measurements.

Found at Cottonwood Creek.

AVES.

The expedition collected parts of four species of birds; a feather from Florissant Col. the distal ends of a humerus, and a femur and a portion of the shaft of an ulna (?) from the Bridger beds, but they are all too uncharacteristic for classification or description.

REPTILIA.

CROCODILIA.

CROCODILUS.

Crocodilus aptus, Leidy.

Contributions to Extinct vertebrate fauna of the Western Territories, p. 126.

Henry's Fork.

Crocodilus Grinnelli, Marsh.

American Journal of Science and Arts, vol. i., p. 465.

From Cottonwood Creek.

Crocodilus Elliotii, Leidy.

Cont. to Ex. Vert. Fauna, p. 126.

Represented by a perfect skull, and several vertebræ.

This fossil exhibits a form of skull which shows characters of both crocodile and alligator; the latter to a less marked degree. That it properly belongs to the former genus is shown by the notch in the upper jaw which receives the canine of the lower.

The entire skull is remarkably flat on its upper surface, the face and cranium being nearly in the same plane without the descent at the frontals usual in these reptiles. The jaw is deeply notched at the sutures between the maxillaries and pre-maxillaries, and the second maxillary notch is well marked. All the bones of the upper surface of the head are deeply pitted.

The borders of the cranium are rounded as they approach the orbits; the superior temporal orifices are almost perfectly circular, the fore-and-aft diameter exceeding the transverse by only one millimetre. This effect may, in some degree, be due to distortion.

To give a more detailed account of the several elements of the skull, we take up first the basioccipital. This bone is remarkably long and straight, tapers gradually downwards, and becomes quite narrow at the distal end. It is smooth throughout, and exhibits no rugose muscular attachments, such as are sometimes seen in other members of the order. The condyle is large and nearly spherical, but with median groove distinctly marked. In size and shape it is more like that of the alligator than of the ordinary crocodile, but it is somewhat different from either. It differs from the former, in not having so long a neck distinctly marked by a constriction; and from the latter, in not having additional articular faces on each side of the condyle proper. As far as can be judged, no portion of it is formed by the exoccipitals. Below the condyle the basioccipital is perforated by two small vascular foramina; the spheno occipital canal occupies the usual place, and is very large.

The exoccipitals are large, of very great width, but rather low from above downwards. The position of the foramina which perforate these bones is peculiar; it resembles more the arrangement seen in the skull of the alligator than in that of the crocodile, but it has an additional foramen. There are, then, two small venous foramina near the condyle; while along the lateral margin of the occiput, are placed in a vertical line the foramina for the hypoglossal and pneumogastric nerves, and the internal carotid artery. The foramen for the facial nerve, etc., is situated in the usual place, and is of the usual size. The foramen magnum is heart-shaped, low, wide above, contracting below. The paroccipital processes are long and slender, and project strongly backwards.

The supra-occipital is very small. It shows to some extent on the upper surface of the skull, wedged in between the parietals. As a whole, the occiput is of remarkable shape: it is perfectly vertical, as in all other crocodilians; is remarkably high from above downwards, and is very broad at top, becoming extremely narrow distally. This latter feature is owing to the peculiar shape of the pterygoids; which, when viewed from behind, do not appear to reach the basioccipital.

The basisphenoid is so destroyed by crushing, that nothing can be said of its shape or of its foramina. It was, however, evidently very stout. The alisphenoid is large and smooth and is not ridged; the foramen ovale is small, and is not produced into an anterior notch. The suture between the alisphenoid and the pro-otic are quite distinct, but the latter is so firmly anchylosed to the quadrate that its limits are indeterminable. None of the other periotic bones are visible.

The quadrate is very long and broad. In shape it resembles the corresponding bone of the alligator, but is somewhat broader. The lower surface is divided into two unequal parts by a conspicuous ridge, which runs to within an inch of the articular surface. This surface has a more decidedly grooved or trochlear appearance than in the common crocodile; but not to the same degree as in the specimen described by Dr. Leidy. It is more like the Mississippi alligator in this respect than any living species of which we have specimens.

The pterygoids are of peculiar shape; they are long, slender, and pointed, and meeting the basioccipital on the median line in front, they project downwards and backwards. Their posterior border is very deeply emarginate, so that they seem to have no connection with each other, or with the basioccipital; instead of having the broad, plate-like appearance of these bones in recent species. The suture between these on the palatal surface is long; and the processes of the pterygoids, which bound the posterior nares, are long and stout. The posterior nares have the position which they take in the recent species; they are visible in the occipital surface, and are directed backwards as well as downwards. They are rather small, and appear to have no septum between them, but this cannot be said with any certainty.

The transpalatine is also somewhat peculiar in shape; the process which joins the pterygoid is of great length, being nearly as long as that bone. The other limbs are more normal in length. The three processes are connected at the usual angle.

The palatals are long and narrow, becoming wider anterior to the foramina. The suture with the maxillaries is rounded, and there are no forward processes as in the true crocodiles; but at the same time, these bones are not of the shape exhibited in the alligators. The palatal foramina are of immense length; they are more than one third as long as the entire bony palate. Their width is also considerable.

The maxillaries are long and very broad; the alveolar border is of about the same shape as in the crocodile, but less decidedly sinuous; and the posterior part passes in below the alveolus of the lower jaw. The convexity of the upper surface of the maxillaries is not so well marked as in the true crocodiles. It is nearly as flat as in the alligator. The palatine plates of the maxillaries are short, broad, and nearly flat, arching slightly to form the alveolus, and perforated along this border by rows of foramina.

The premaxillaries are very short; they curve strongly outwards from the notch and enclose the large anterior narial opening, which is distinctively crocodilian (as distinguished from other genera) in shape. The muzzle ends quite sharply. The palatine processes are short and convex in both directions, and the incisive foramen is heart-shaped. The alveolus is quite regular in outline; it is pitted in front for the first mandibular teeth, but there is no perforation for them.

The teeth are short, stout, compressed so as to form cutting-edges, and are somewhat obtuse. They are finely striated from base to tip. The premaxillary held four teeth; these are all broken off, but from their fangs it appears that they formed an uninterrupted row, and were subequal in size. The maxillary accommodated fifteen teeth, of which the fifth is the largest, and forms a very prominent canine. The posterior maxillary teeth are proportionately larger, and more equal than in either crocodile or alligator.

The nasals are rather broad; they send processes into the anterior narial opening, which tend to divide it, but this division was probably not complete. The limits of the prefrontals and lachrymals are so obscure as to preclude description.

The frontals are long and very narrow, though wider than in the alligator. They are smooth and flat, exhibiting no concavity on top. They expand considerably at the posterior part of the orbit, at the sutures with the post-frontals. These bones are long, stout, and curved very strongly outwards.

The mastoids are of remarkable size; they project far backward along the tympanic, and encroach largely upon the occipital region. It is partly owing to this that the occiput is so high.

The parietals are short, and very narrow between the temporal orifices, behind these they expand considerably. The orbits are large and of irregular shape.

The malar is long and rather slender.

Measurements.

The mandible is long, rather shallow, but very thick. The symphysis is very long, extending as far as the seventh tooth. The chin is quite sharp, but becomes broad, as the rami diverge quite rapidly. The alveolar border is rounded and comparatively straight, the median enlargement of the dentary is in thickness rather than in height. The two rami diverge at an angle which is more open than in the true crocodiles, and less so than in the alligator. The mandibular foramen is smaller than in the latter genus, but corresponds with it in position; it has its long diameter parallel with, and not oblique to, the alveolus. The mandibular fossa is extremely large and deep. The splenial is long and stout, ends obtusely, and does not reach the symphysis. The articular cavity is broad from side to side, but rather shallow; it is not divided into two distinct facets as in the alligator. The post-glenoid process is very stout; it projects but slightly upwards, less so than in either crocodile or alligator. It has no median ridge as in the former genus, and is tuberous at the end.

The teeth are much like those of the upper jaw, but are somewhat sharper and more conical; they are not recurved, and have no distinct constriction, as is found in most of the recent species. There are about eighteen teeth to each ramus; the first is large and sharp, and is followed by two small ones and then by the canine. The remaining teeth do not exhibit any great differences of size.

Measurements.

Vertebræ.

Cervicals.—The centra are long and nearly cylindrical, expanding slightly near the anterior face. The hypapophyses are short and broad; they project forwards, and are somewhat compressed. The vascular foramina correspond in size and position to those of the alligator. The neural canal is small and subcircular, having comparatively short but very stout neurapophyses, which are perforated behind the diapophyses. These are short and stout, and are developed from the neurapophyses alone. The zygapophyses are long and flat; the anterior ones project almost vertically. The neural spines are stout, and of greater antero-posterior extent than in the alligator.

Dorsals.—A few of the anterior dorsals have strong hypapophyses. The centra of all are long and stout. The neural canal is smaller than in the cervical region; it has strong neurapophyses, which develop long and depressed diapophyses. The neural spines are low and broad. The zygapophyses are developed on the laminæ, and do not project upwards as in the cervical region.

The lumbars are much like the dorsals, except that they are longer, and have very large and depressed diapophyses, which project somewhat upwards.

Measurements.

Dorsal.

Lumbar.

The dermal scutes are long ellipses, deeply pitted on one side, but without a trace of a keel. Their edges show no signs of sutural union.

The bones described indicate a reptile about fifteen feet long. They were found near Smith's Fork, Wyoming.

Crocodilus parvus, sp. nov.

A small reptile represented by sixteen vertebræ and a portion of the pelvis.

The cervicals have short centra, with very deep articular cups and hemispherical heads: the latter have a prominent rim around the base. The hypapophyses are short, stout, and very nearly vertical in direction; the sides of the centra are channelled by a deep vertebraterial canal; the parapophyses are developed very low down, and are very prominent. The diapophyses are developed partly from the centra and partly from the neurapophyses; they are stout and very short. The facets for the ribs are developed in the usual place. The neural arch is rather high, and forms a small, narrow canal; the proportions of the neurapophyses and neural spines are about as in Alligator mississippiensis, but the zygapophyses are not so prominent.

The dorsals show a considerable increase in size over the cervicals; the centra become elongate, and the articular cups shallower and transversely oval. Several of the anterior vertebræ retain large hypapophyses. In the dorsal region the diapophyses are developed from the neurapophyses alone, and at a considerable height above the neuro-central suture; they are long and depressed. The zygapophyses and neural spines present no peculiarities of structure.

In the lumbar region the vertebræ regain their cylindrical form, and become still more elongate; but the cups are comparatively shallow and the heads low; there is no distinct shoulder. The neural canal is small, with low, broad neurapophyses, from which are developed very broad and depressed diapophyses, which project outwards in a horizontal plane. The neural spines are thick, and broad antero-posteriorly, but are so broken that their height cannot be determined.

In both dorsal and lumbar region the neurapophyses are deeply notched on their posterior edges, and close to the neuro-central sutures, for the passage of the spinal nerves.

The ilium is very high compared with most crocodiles; its vertical diameter is considerably more than half of the antero-posterior diameter. The construction of the bone is very much like that in the modern Crocodilia; but the suprailiac border is more regular, and the anterior tuberosity is not so thick or so much everted as in these forms. The acetabulum is small, shallow, directed downwards and outwards, and situated considerably forward of the median line. The iliac surface is smooth, but very irregular, being very deeply concave above the acetabulum, and convex behind it. The sacral surface is rugose, rises above the sacrum, and shows attachments for two sacral vertebræ. Thus the construction of the entire pelvis shows but very little variation from the modern type.

Measurements.

Crocodilus heterodon, Cope.

Alligator heterodon, Proc. American Philosophical Society, 1872, p. 544.

Represented by a single tooth from the posterior part of the mandibular series. It agrees very closely with the corresponding tooth of Alligator mississippiensis, but presents some differences. The crown is very low, obtuse, and finely striate; it is compressed and shows a cutting-edge. Its longest diameter is fore-and-aft; both this and the transverse diameter are proportionately greater than in the modern species. The constriction of the neck is very decided; the fang is large, and especially thick.

Measurements.

Crocodilus clavis, Cope.

U. S. Geol. Survey of Terrs. 1872, p. 612.

This species is indicated by the remains of a crocodilian larger than Crocodilus Elliotii, but very different from it. The pitting of the dermal scutes, and of all the cranial bones, is deeper than in any other of the Bridger crocodilians in our possession, and very strongly resembles that in Alligator mississippiensis.

The mandible has a long symphysis, and the alveolar border shows the sudden deep depression just behind it, which is so marked in the ordinary alligator. The rami, however, do not diverge at such an open angle. The jaw is very stout, and is deeper and thinner than in Crocodilus Elliotii; and is of about the same proportionate thickness, but deeper than in the alligator. The splenial ends obtusely, and approaches the symphysis somewhat more closely than in the alligator, but does not enter into its formation. The teeth are stout and obtusely conical, not striate, and implanted very close together; they exhibit about the same alternation of size as do those of the alligator. What appears to be the canine is small; it is preceded by a much smaller, and succeeded by a slightly smaller tooth. The dermal scutes are quadrate in shape; they are deeply and irregularly pitted, and have a low but distinct longitudinal keel; they are suturally united by their lateral borders.

CHELONIA.

The Bridger beds have yielded a great abundance and variety of land, marsh, and fresh-water chelonians. They present much variation of form and size; and, owing to the great pressure in the strata, scarcely any two specimens of the same species are alike; occasionally, however, an undistorted specimen is obtained.

The most abundant remains of turtles are those of a species of the recent genus Emys, which are found in all the beds, and are, perhaps, the commonest fossils of the basin. The genera Trionyx and Hadrianus (Testudo, Leidy) follow next in order.

HADRIANUS, Cope.

Resembles Testudo in form, but has two analscuta, as have most Emydidæ.

Hadrianus allabiatus, Cope.

U. S. Geol. Survey of Territories, 1872, p. 630.

Represented by two ungual phalanges which resemble the claws of Testudo, but are proportionately shorter, broader, and not so pointed at the ends. They are oval in section, both longitudinally and transversely; the articular faces are deep and subinferior.

From Henry's Fork.

Hadrianus octonarius, Cope.

Geol. Survey of Terrs., 1872. p 630.

Represented by the right humerus of a large individual.

This bone is intermediate in character between the corresponding bones of Testudo and Emys. The head is longer and narrower than in the former genus; it is implanted on a short, distinct neck, and is strongly convex in both directions. The articular surface extends to the base of the internal tuberosity. The tuberosities, especially the external one, are very large and thick. The external rises above the head, and resembles that of Emys in shape. The fossa separating the tuberosities is comparatively narrow. The shaft is much like that of Emys, but is somewhat more strongly curved; not so much, however, as in Testudo, and the distal end is not so much flattened. The anconeal fossa is wider and deeper than in either genus. The trochlea is broad, and divided by an obscure groove into a small and convex radial face, and a nearly plane (transversely) ulnar face. The condyles are prominent and rugose.

Found near Dry Creek.

EMYS.

Emys wyomingensis, Leidy.

Cont. to Ex. Vert. Fauna, p. 140.

Represented by six perfect shells from Cottonwood and Dry Creeks, and Henry's Fork, and a shoulder girdle from Cottonwood Creek, which is provisionally referred to this species.

This species, when adult, was upward of a foot in length, and in the composition of the shell, number of scutes, etc., resembled the living species of the genus.

The Shoulder Girdle has the form characteristic of the Emydidæ, but presents some peculiarities. The scapula is short, not being as long as the coracoid, and is not so straight or cylindrical as is usual in Emys; but is compressed, and somewhat recurved, and tapers towards the upper extremity, which is marked by a smooth rounded facet for the cartilaginous supra-scapula. The precoracoid is long, sub-cylindrical at its origin, but becomes broad and flat distally; at the extremity it is longitudinally striated. The proximal end is flexed forward at an obtuse angle, and is expanded to form the long suture with the scapula and coracoid. It contributes considerably to the glenoid cavity. The coracoid is remarkably long, and after leaving the sutures with the other elements of the girdle, becomes very broad and thin. This is most marked distally. The anterior border is thickened, and the bone is slightly concave on both surfaces.

The three parts of the shoulder girdle are united by distinct bony symphyses; they differ from some of the modern species, in which there is only a ligamentous union between the coracoid and the other parts. It presents a further difference in the long and slender neck which is formed by the flexing of the precoracoid, and in the shallow and subcircular glenoid cavity. The short scapula and long coracoid would indicate a species with a low, broad carapace, as was probably the case in E. wyomingensis, though much difficulty has been experienced in determining this point, owing to the distortion of the specimens.

Measurements.

BAENA, Leidy.

Baena undata, Leidy.

Cont. to Ex. Vert. Fauna, p. 160.

Three nearly perfect shells of different ages, from Dry and Cottonwood Creeks.

TRIONYX, Geoffr.

Trionyx uintaensis, Leidy.

Cont. to Ex. Vert. Fauna, p 176.

Cottonwood Creek.

PISCES.

TELEOSTEI.

TELEOCEPHALI.

CYPRINODONTIDÆ.

"Head and body covered with scales; barbels, none. Margin of the upper jaw formed by the premaxillaries only. Teeth in both jaws; upper and lower pharyngeals, with cardiform teeth. Dorsal fin situated on the hinder half of the body." (Günther.)

TRICOPHANES, Cope.

U. S. Geolog. Surveyor the Terrs., 1872, p. 641.

Having secured a very perfect specimen of this genus, we are enabled to complete the definition of its generic characters. We give, then, Professor Cope's definition, with some emendations and additions: Dorsal and anal fins short; ventral fin sometimes beneath and sometimes in advance of the dorsal. The premaxillary forms all of the superior arcade of the mouth, which has a wide gape, opening back behind the orbit. This bone has a row of long, slender, recurved, and subequal teeth implanted in it. The dentary is stout, and has a few small teeth. The branchiostegal rays are six in number, and are rather wide. The preoperculum IS serrate. The operculum is ridged on top. The anterior vertebræ are unmodified, and the centra are not elongate. A strong acute spine supports the dorsal, and a similar one the anal fin. There is a long post-clavicle, which may or may not extend to the base of the ventral parallel with the femur. The femur is long and furcate; the external part straight and reaching to the clavicle; the internal curves to meet the corresponding portion of its fellow. The ventral radii are eight in number, and the caudal fin is furcate. The scales are peculiar, and characteristic of the genus. They are very thin, and have borders fringed with long, close-set, bristle-like processes. This genus includes as yet only three species: T. hians, from Osivio, Nev.; and T. foliarum and T. Copei, from Florissant, Col.

Tricophanes Copei, sp. nov.

Vertebræ D. 12, C. 18, Radii D. 14, A. 8, V. 8, C. 41, P. 5 only visible, not all preserved. The dorsal fin is long, and projects beyond the beginning of the anal fin; the mouth is terminal, and the muzzle rather sharp. All the bones of the skeleton are very slender; and this is especially true of the ribs, which are not as thick as the interneurals. The neural and hæmal spines are short and slender. The origin of the dorsal is nearer to the muzzle than to the caudal; though, as a whole, the fin is on the hinder half of the body. There are no interneural spines in front of the dorsal fin; those supporting the fin are short, slender, and without the laminar expansions found in T. foliarum. The caudal fin consists of numerous jointed rays, which are supported by the neural and hæmal spines of the last three vertebræ. The scales are small, and exhibit the peculiarities of the genus, but the rows are too imperfect to be counted.

Measurements.

Found in the insect beds at Florissant, Col.

CATOSTOMIDÆ.

Body covered with scales; head naked; margin of upper jaw formed by the premaxillaries; mouth toothless. Pharyngeal teeth in a single series, and exceedingly numerous and closely set. Dorsal fin elongate and opposite the ventrals. Anal short, or of moderate length.

AMYZON, Cope.

U. S. Geolog. Survey of the Terrs., 1872, p. 642.

Allied to Bubalichthys. Dorsal fin elongate, with a few fulcral spines in front. There are three broad branchiostegals. The vertebræ are short, and the hæmal spines of the caudal fin are distinct and rather narrow. The teeth are arranged comb-like, are truncate, and number from thirty to forty. The dentary bone is slender and toothless, and the angular is distinct.

Amyzon commune, Cope.

U. S. Geolog. Survey of Terrs., 1873, p.

Represented by several fine specimens from near Castello's Ranch, Col.

SAURODONTIDÆ.

For a very complete definition of this family, see Cope's Cretac. Vert., p. 183.

PORTHEUS, Cope.

Cretac. Vert., p. 189 et seq.

"Teeth subcylindric, without serrate or cutting edges, occupying the maxillary, premaxillary, and dentary bones; size, irregular; premaxillary, median maxillary, and dentary much reduced. No foramina on inner face of jaws. Teeth on the premaxillary reduced in number. Opercular and pre-opercular bones very thin. Cranial bones not sculptured."

Portheus thaumas (?), Cope.

Loc. cit. p. 196.

Maxillary large, teeth three; third mandibular small, without cross groove in front of it.

A single tooth from the cretaceous sandstone of Cement Gulch, Col., is provisionally referred to this species; the reference cannot be certain, as the specimens described and figured by Professor Cope have the crowns of the teeth broken. The tooth is not so long as the largest tooth of P. molossus, but is of proportionately greater diameter and not so straight. It is conical and recurved, and shows two very obscure cutting-edges, which divide the crown into two unequal faces. It has faint longitudinal striations on all sides, and the apex is sharp.

Measurements.

NEMATOGNATHI.

SILURIDÆ.

"Skin naked, or with osseous scutes, but without scales. Barbels always present; maxillary bone rudimentary, margin of the upper jaw formed by the premaxillaries only. Suboperculum absent; adipose fin present or absent." (Günther.)

RHINEASTES, Cope.

U. S. Geol. Survey of the Terrs., 1872, p. 638.

A genus allied to the recent Ichtælurus but differing in the inferior grooving of the vertebræ and in the rough exostoses of the cranial bones. It differs from Phareodon in having the usual band of bristle-like teeth on the dentary.

Rhineastes —— ?

Represented by a portion of the dentary and hyomandibular bones of a large cat-fish from Bridger Butte.

The dentary is broad and shallow, grooved below, and deeply striated on the external face. As much of it as is preserved is straight. The teeth are small, subequal throughout, and very numerous. The hyomandibular is broad and thick, and has a striated surface. The condyle is peculiar in having two separate articular faces above and below, one convex and the other flat.

GANOIDEI.

CYCLOGANOIDEI.

AMIIDÆ.

"Scales cycloid; a long, soft dorsal fin. Abdominal and caudal parts of the vertebral column subequal in extent." (Günther.)

AMIA.

Body elongate sub-cylindrical, compressed behind; snout short and rounded. Jaws with an outer series of closely-set pointed teeth, and with a band of small teeth, similar teeth on the vomer, palatine, and pterygoid bones. Long dorsal, short anal, and rounded nonfurcate caudal fin. Ventrals well developed. A single large gular plate; branchiostegal rays ten to twelve.

Amia (Protamia) uintaensis, Leidy.

Cont. to Ext. Vert. Fauna, p. 185.

A species of large mud-fishes related to the modern Amia calva. The vertebræ are all much wider than they are high. The articular cones have their bottoms considerably above the centre, and are minutely perforate for the notochord. The centrum is transversely curved from side to side, and has the convexity directed forwards; it is truncate below, making the infero-lateral angles quite prominent in the anterior dorsal region; in the posterior there are two fossæ. The diapophyses are large, but almost sessile, and take their origin above the centre, on the same line as the bottom of the articular cone. The facets for the neurapophyses are in the form of the figure 8; their internal borders are prominent. The atlas has a broad oval centrum, which is not truncate below, and has no markings of any kind on the under surface. The articular faces for the neurapophyses are prominent, and approach near together. The depression for the occipital condyle is small, circular, and situated above the centre.

From Henry's Fork.

Amia depressa (?), Marsh.

Pr. Ac. Nat. Sc. 1871, p. 103

In this species the dorsal centra are wide, low, and short, and of a regular oval outline. The articular cones are shallow, and have their bottoms but slightly above the centre. The neurapophysial facets are deep, with prominent borders, and the diapophyses are sessile. The chief peculiarity is that the under surface of the centrum has no markings of any kind.

As Professor Marsh has given no measurements, the reference to A. depressa cannot be certain.

The specimen was found at Henry's Fork.

Amia scutata, Cope.

Bull, of U. S. Geol. Survey, No. 1 of Series II, p

A species of about the size of A. calva, but with a proportionately larger head. It is represented in our collection by a specimen which lacks only a portion of the caudal and pectoral fins. The premaxillary is short and stout, articulates closely with the maxillary, and bears a single row of pointed recurved teeth. These are shorter and straighter than in A. calva. The maxillary is much as in the modern species, but is rounder. The cranio-facial axis is straight and broad; the basioccipital is the largest of the bones; the basisphenoid and presphenoid are of the usual shape and size, but there is a constriction at their junction which is not marked in the modern species. The vomer is long and double, and at the extremity is armed with rows of small teeth. The two portions diverge more perceptibly than in A. calva, and are stouter, though this appearance may, to some extent, be due to flattening.

The frontal is long, broad, and thick; the upper surface is delicately sculptured in a somewhat different pattern from that seen in the modern species. The parietal is short and broad, while the epiotic is unusually narrow. The mandible is long and slender; the rami are incurved anteriorly, but apparently not to the same extent as in A. calva. The articular has the shape of a long and narrow wedge; it does not form a very close articulation with the dentary. The dentary is long and comparatively slender, has a rounded outline, and is occupied by an external row of large, and an internal band of small teeth. The mandibular teeth, like those of the upper jaw, are somewhat different from the teeth of A. calva; they are shorter, stouter, and are not so much incurved or recurved. They are very sharp, and show a constriction below the apex. The small teeth are of the usual size and shape. The jugular plate is well developed, and is long and narrow. The hyoid arch is very much the same as that shown in the recent species; the characteristic flat branchiostegals are well marked; they appear to be thirteen in number.

The scapular arch is long and stout. The clavicle is strongly bent, the supra-clavicle is short, and the post-clavicle is long. The pectoral fin is too indistinct for description.

The vertebræ are of considerable depth in the anterior dorsal region, and decrease steadily in size as they go backwards. The neural spines are long and slender, and project strongly backwards. The relation of the centra to the arches seems to be about that seen in A. calva, but the neurapophyses are more slender. The diapophyses are long and slender, in this respect differing from the Bridger species and approaching the modern one. The dorsals are thirty-five in number. The caudals number about forty-seven. They have smaller centra, but longer and stronger neurapophyses than the dorsals. The hæmal arch is long, and the hæmapophyses articulate movably with the centra. The spines supporting the caudal fin rays are very stout. The dorsal fin is long and soft, and has long interneurals supporting short rays; these are fifty-three in number. The anal fin, on the other hand, is very short, having but nine rays, which are long and jointed, and articulate with short interhæmals. The caudal fin appears to be of the usual form. The femur is of the general shape characteristic of Amia, but is not just like that of A. calva. It is shorter, broader at the proximal end, while the distal end is narrower, and has a deeper constriction just above it. The ventral fins are placed under the middle of the dorsal region, and have each ten rays. The scales are of the usual cycloidal shape, and minutely striate.

Measurements.

From the insect beds near Florissant, Col.

PAPPICHTHYS, Cope.

U. S. Geol. Survey of the Terrs., 1872, p. 634.

Vertebræ short, dorsal with projecting diapophyses. Maxillary and dentary bones support but one series of teeth.

Pappichthys plicatus, Cope.

Loc. cit., p. 635.

From Henry's Fork.

Pappichthys lævis, Cope.

Loc. cit., p. 366.

Represented by three vertebræ from the posterior part of the dorsal region. The centra are subcircular and have deep articular cones, with their bottoms above the centre, and minutely perforate for the notochord. The centra are comparatively quite long, and have prominent projecting rims, and are truncate beneath. The facets for the neurapophyses are long, and are separated into two parts for the contiguous arches. The diapophyses are short and stout.

Measurements.

Found at Henry's Fork.

Pappichthys symphysis, Cope.

Loc. cit., p. 636.

Found at Cottonwood Creek.

ELASMOBRANCHII.

PLAGIOSTOMATA.

CARCHARIDÆ.

"Eye with a nictitating membrane. An anal fin; two dorsals."

GALEOCERDO.

Caudal fin with a double notch; mouth crescent shaped; teeth subequal in both jaws, oblique, serrate on both margins.

Galeocerdo falcatus, Ag.

Corax falcatus, Poiss. Foss., t. iii., p. 226.

This species is represented by a single tooth from the cretaceous sandstone near the Garden of the Gods, Col. It does not agree exactly with any descriptions or plates which we have seen; but the differences are probably owing to the position or age of the specimen. The crown is low, broad, and not very acute, the edge is finely serrate, and there is no sensible difference between the serrations of the two borders. The anterior border is undulating in outline, but for the most part is convex; the posterior is short and straight, and sends out quite a long heel. One face of the crown is flat and the other is strongly convex. The root is stout and divided into two fangs, which are longer and more distinct than is common in this species. There are no denticles; cementum smooth.

Measurements.

Galeocerdo hartwellii, Cope.

Cret. Vert, p.. 244.

This species belongs to the group G. Egertonii, Ag., having the two edges subequal and symmetrical. A single tooth from Cement Gulch, Col.

CESTRACIONTIDÆ.

"Two dorsal fins, an anal; nasal and buccal cavities confluent. Teeth obtuse, several series being in function." (Günther.)

Ptychodus, Ag.

Poissons Fossiles, t. iii., p. 56.

Ptychodus Whippleyi, Marcou.

Geology of North America, 1858, p. 33.

Represented by a tooth from the cretaceous of Cement Gulch, almost identical with the specimen described by Dr. Leidy from the cretaceous of Texas. (Cont. to Ext. Vert. Fauna, p. 300.)

SUMMARY.

MAMMALIA.

AVES.

REPTILIA.

PISCES.

EXPLANATION OF PLATE A.

Figure about one fourth natural size.

Uintatherium Leidianum.