402 NOTES ON THE CANID^ OF THE WHITE RIVER OLIGOCENE. 



from the Old World, belonging to the series which leads from the Oligocene Cephalogale 

 to the Pliocene Simocyon. The clogs of the Loup Fork, with the exception of the aber- 

 rant JElurodon, are very imperfectly known and the remains of them which have been 

 found are not, according to present knowledge, generically separable from Canis, though it 

 hardly seems probable that the modern genus had actually been differentiated so early as 

 the upper Miocene, and we may regard it as extremely likely that these supposed repre- 

 sentatives of Canis will eventually prove to belong to more primitive genera. None of 

 the forms which have hitherto been found in the Loup Fork beds can be referred to the 

 Oynodictis line. 



Tbe mutual relationships between the two canine series, which are already so well 

 distinguished in tbe Uinta, are quite obscure and puzzling, although there is nothing to 

 forbid the assumption that both series converge to a common ancestor in the Bridger, per- 

 haps the genus Miacis. The Oynodictis series, when we first meet with it, is decidedly 

 more advanced than the other phylum, as is shown in the development of the skull, the 

 reduction of the dentition, the character of the limits and feet and the digitigrade gait. 

 Continuing through the White River age ami, so tar as North America is concerned, at- 

 taining its maximum of development in the abundance and variety of its species in the 

 John Day, the line apparently disappears and can be traced no farther. Whether the 

 scries actually died out at the end of the John Day, or whether it continued farther and 

 possesses representatives even at the present time, are questions which cannot yet be defi- 

 nitively answered. Schlosser ('88, p. 247) has suggested that some of the species of Cync- 

 dictis may, perhaps, be of phylogenetic significance in the canine stem, but if so, they 

 can hardly lie placed in the thooid series, which apparently has no place for them. M. 

 Boule ('89, p. 321 ), in an article upon the Pliocene Canis megamastoides Pome], comes to 

 the conclusion that the modern Canidce are diphyletic, and have arisen by a process of 

 convergence, tin- thooids and the bears being divergent groups derived from Amphicyon, 

 while the alopecoids and viverrines are descended from Oynodictis. In discussing the 

 affinities of the Pliocene form Boule says: 



" La description precedente nous montre que le fossile de Perrier se rattachede plus 

 pres aux Renards qu' mix autres representants actuels de la famille des Canides. Par 

 son crane, le Canis megamastoides ressemble beaucoup le Renard de uos pays. Par la 

 forme de sa niandibule, il se place au contraire pres des Renards americains (Canis 

 cancrivorus, C. azaro3, C. cinereoargentatus) et pres del' Otocyon megalotis de l'Afrique 

 australe. Ces especes, notamment la derniere, sont regardees par tous les auteurs com- 

 me des formes primitives. 



'" Tout en ratifiant ce premier rapprochement, la dentition presente des caracteres 

 particuliers que nous retrouvons en grande partie dans les Oynodictis et Cephalogale du 

 Miocene (p. 327). 



