M. R. Thorpe — Neiv Fossil Carnivora. ttTD 



The two species, 8. ijrimifjenius and S. diaphorus, are 

 so unlike that I doubt the validity of this classification. 

 In fact, it seems that Pliocyon mar ski is closer to S. priml- 

 genius than is S. diaphorus, but I do not believe that this 

 new form should be considered as a species of Simocyon. 

 Pliocyon is of later age than S. primigenius, but in some 



Fig. 2. — Pliocyon marsM, geu. et sp. iiov. Holotype. Internal lateral 

 view. X 4/5- 



respects it seems to show less advanced characters. Both 

 were brachycephalic forms and had, of course, reached 

 a high degree of specialization. The exact taxonomic 

 position of the new JNTorth American form can not be 

 determined on the presence of this one ramus. Appar- 

 ently, however, we can safely conclude that Pliocyon is the 

 Xew World representative of the Pikermi Simocyon. 



/0 04^ TYPE 



Y P M 



Fig. 3. — Pliocyon marsM, gen. 

 X 4/5. 



et sp. nov. Holotype. Superior view. 



OligoJmnis Cope. 



When Cope described this genus in 1881, he considered 

 it ancestral to Icticyon Lund, and as allied to the Canid^. 

 The type,- 0. crassivultiis, is from the John Day beds. 

 In 1907 Matthew reexamined the type and referred it to 

 the Mustelid^. 



The dental formula is I|, C|, P^% M|. Cope did not 

 know of the existence of ]\P and used its supposed absence 

 in part as a generic distinction from Icticyon. The type^ 



