1872.] 481 [Cope. 
distinct. The premaxillary appears to extend beneath the whole length 
of the maxillary. Should this feature be substantiated, it will indi- 
cate a resemblance to Cyprinidz. The maxillary has a high expansion 
of its superior margin, and then contracts towards its extremity. Above 
it two bones descend steeply from above, which may be out of position. 
The preoperculum is not serrate. The superior ribs are well developed. 
This form approaches, in its anterior mouth, the true Cyprinide 
through Bubalichthys. It is the first extinct form of Catostomidee found 
in this country. 
AMYZON MENTALE. Cope. Species nova. 
This fish oecurs in considerable numbers in the Osino shales, and nu- 
merous specimens have been procured. Two only of these are before 
me at present. They are of nearly similar length, viz., M. O. .12 and 
.105. The most elevated portion of the dorsal outline is immediately iv 
front of the dorsal fin. From this point the body contracts regularly » 
the caudal fin. The dorsal fin is long, and is elevated in front and con- 
cave in outline, the last rays being quite short. They terminate one 
half the length of the fin in front of the caudal fin. The interneural 
spines are stout in front and weak behind. Radii, III. 26, and (?) IT. 23. 
There are about twenty-three vertebre between the first interneural 
spine and the end of the series in the former specimen, in which, also, 
there are no distinct remains of scales. In the second, scales are pre- 
served, but no trace of lateral line; there are six or seven longitudinal 
rows above the vertebral column. The anal fin is preserved somewhat 
damaged ; the rays are not very long, and number II. 7. The anterior 
interhemal is expanded into a keel anteriorly. Ventral fins injured. 
The ribs and supplementaries are well developed. The inferior quad- 
rate is a broad bone, with deep emargination for the symplectic. Depth 
No. 2 in front of dorsal fin, M .025. Length basis of dorsal, .026. 
ON THE EXISTENCE OF DINOSAURIA IN THE TRANSITION 
BEDS OF WYOMING. 
By Epwarp D. Cops. 
(Read before the American Philosophical Society, Sept. 19, 1872.) 
During the present season, F. B. Meek, of Dr. F. V. Hayden’s Geolog- 
ical Survey of the Territories, discovered some large bones near Black 
Buttes Station, on the Union Pacific Railroad, fifty-two miles east of 
Green River, and near the Hallville Coal Mines. Shortly afterwards I 
visited the spot with a branch expedition, and commenced excavations 
with a view to the recovery of the remainder of the animal. The posi- 
tion was discovered to be between the thinner or lower strata of the 
Bitter Creek series of coal, which at this point, occupy a position of 
elevation and crop out high on the bluffs. Two strata appear above the 
A. P. §8.—VOL. XII.—3I 
