Stewart.] Cretaceous Fishes. 361 



Pachyrhizodus minimus. 



Pachyrhizodus minimus Stewart, Kans. Univ. Quart., vol. vnr, pp. 37, 38. 



This species is represented by the mandibles alone, which are 

 characterized as follows : The dentaries are slender and slightly 

 incurved at the symphysis, where they also seem to be bent 

 slightly downward. The symphysis is bifurcated by a deep 

 groove on the external side, but internally it is continuous from 

 above downward. On the external side there is a shallow groove 

 just below the alveolar border, which becomes indistinct toward 

 the symphysis : the lower border of the bone is sharp and nearly 

 straight. There are eleven teeth preserved upon one of the 

 rami, and room for at least as many more. They are conical, 

 non-striated, and directed inward; the last is situated quite a 

 distance from the coronoid' angle, below which there is quite a 

 depression. 



Only a small portion of the articular is exposed on the ex- 

 ternal side, but internally it extends well forward. The cotylus 

 is very convex transversally and situated w T ell up toward the 

 coronoid process, while below and extending backward from it 

 on the external side is the prominent hook-like, angular process 

 found in this and other genera of fishes. 



Length of alveolar border from coronoid angle 52.0 mm. 



Depth at coronoid angle 10.0 " 



Length of bone from cotyloid cavity 56.0 " 



Number of teeth in one centimeter, 4. 



The specimen, No. 327, was found by myself in the Butte 

 creek region of Logan county, Kansas, during the summer of 

 1898. 



24— vi 



