442 E. L. Troxell — Entelodonts in Marsh Collection. 



Chcerodon caninus Geoup. 

 Cheer odon caninus, gen. et sp. nov. 



Genoholotvpe, Cat, Xo. 11665, Y. P. M. Middle John Day, Oregon. 



Well preserved skulls or skeletons from the John Day 

 beds of Oregon are very rare, bnt one exceptionally com- 

 plete skull and jaws (figs. 19, 20) of an entelodont was 

 secured by Professor Marsh in 1876. It was found by 

 "William Day in Turtle Cove, in beds which Sinclair says 

 (1905, p. 134) belong to the Dicer atherium zone of the 



Fig. 19. — Chcerodon caninus, gen. et sp. nov. Genoliolotype. 

 11665. Side view of skull and lower jaws. One-fifth nat. size. 



Middle John Day. This fine specimen is here made the 

 type of a new genus and species. 



The fact that it came from the John Day region makes 

 it seem probable that it is related to Archceotherium ro- 

 bustiim (Leidy) and to Chcerodon calkinsi (Sinclair). 

 From the former it is distinguished by the greater size 

 and the more prominent cusps, especially those of the 

 lower molars, anterior. There is, on the other hand, a 

 remarkable similarity to C. calkinsi in proportions and 

 size, judging from the measurements given by Sinclair. 

 The difference lies in the processes, long and extended far 

 backward, in the presence of anterior mental tubercles, 

 and in the long curved canines. 



This difference in the mental tubercles separates the 

 specimens widely, unless we admit the theory that this 



