GEOLOGICAL SUEVEY OF THE TERRITOEIES. 643 



ity. Above it two bones descend steeply from above, which may be out 

 o±' position. The preopercuhim is not serrate. The superior ribs are 

 well developed. This form approaches, in its anterior moutb, the true 

 Cyprinidre through Buhaliclitliys. It is the first extinct form of Catos- 

 tomidte found in this country. 



AlHYZON IIENTALE. Cope. 

 Log. cit., p. 481. , 



This fish occurs in considerable numbers in the Osino Shales, and 

 numerous 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 

 in front of the dorsal fin. From this point the body contracts regularly 

 to the caudal fin. The dorsal fin is long, and is elevated in front and 

 concave 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. Eadii, III. 26, and (?) 11. 

 23. There are about twenty-three vertebrse 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. 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 

 interheemal 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 

 IS"o. 2 in front of dorsal fin, M. .025; length basis of dorsal, .026. 



From the paper-coal of Osino, Nevada. 



EEYIEW OF THE TEETEBEATE FAUNA OF THE EOCENE 



OF WYOMING. 



The number of species above recorded, as obtained by the expedition, 

 is as follows : 



MAIVIMALIA, (45.) 



Species. 



Quadrumana , 3 



Carnivora - 6 



Probdicidia ' 8 



Perissodactyla 14 



Eodentia 6 



Marsupialia • 1 



Incertse sedis 7 



AVES, (3.) 



Incertse sedis 3 



KEPTILIA, (44.) 



Crocodilia g 



Testudinata 32 



Lacertilia 3 



Ophidia i 



