io6 



CES TRA CIONTID&. 



" Two dorsal fins, an anal ; nasal and buccal cavities con- 

 fluent. Teeth obtuse, several series being in function." 

 (Gunther.) 



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.) 





