NOTES ON THE CANIDJ5 OF THE WHITE RIVER OLIGOCENE. 401 



Still another species should be mentioned in this connection. In the American 

 Museum of Natural History, New York, are the remains of a small cynoid animal from 

 the Uinta beds, which may belong to Cynodictis, or if not, should be referred to some 

 closely allied genus. It is important to observe that in the Uinta stage (uppermost 

 • Eocene or lowest Oligocene) we find that the two canine series, represented in White 

 River times by Daphcenus and Cynodictis, had already been established. 



The Phylogeny of the Canid.e. 



It seems probable that the fossil genera of this family already known are sufficient 

 to indicate to us the main outlines of its phylogenetic history. The problem of recon- 

 structing the series is, however, obscured by two circumstances ; first, the variety and 

 multiplicity of nearly allied genera, the mutual relationships of which are very complex 

 and difficult to disentangle ; and in the second place, by the fact that only rarely do we 

 obtain satisfactory material pf any of the genera. Most of the forms are known only 

 from the skull ami teeth, and the skeleton has. so far, been found in but few of the 

 species. Cynodictis, Daphcenus, Temnocyon and JElurodon are now known from more 

 or less complete skeletons, but we shall need to learn far more than we know at present 

 concerning the structure of the other genera before we can reach a solution of the manv 

 problems of canine phylogeny. 



Before taking up the discussion of these phylogenetic problems, it will be conveni- 

 ent to establish the order of geological succession in which the various genera make their 

 appearance. We have seen that in the Uinta there appear to be two distinctly sepa- 

 rated canine series, one of which is represented by f Miaeis and the other by a genus 

 which is very closely allied to, if not identical with Cynodictis. The former series would 

 seem to be continued into the White River by Daphcenus and the latter, of course, by 

 Cynodictis. The latter genus may well prove to be of Old World origin, for in the 

 European Oligocene it attains such a variety and fullness of development as it never 

 reached in America, although, on the other hand, the American creodont genus Miaeis, 

 from which Cynodictis probably took its origin, has not yet been found in Europe. In 

 the John Day stage the canine phylum underwent an extraordinary expansion. Daphce- 

 nus persisted, but is represented only by a single small species, D. cuspiycrus, while the 

 series branched out into several distinct and more or less specialized genera, such as 

 Temnocyon, Hypotemnodon, Cynodesmus, Enhydroeyon, and perhaps even the little known 

 Hycenocyon. No new genera of the Cynodictis series have yet been detected, but that 

 genus itself became, differentiated into many more species than occur in the White River, 

 and some of these may, on better knowledge, prove to be generic-ally distinct. On the 

 other hand, Oliyobunis probably represents, as Schlosser has suggested, an immigrant 



