1899-] Worttnaii and Matthew, Ancestry of the Canidce, etc. I 15 



2510) of the American Museum collection, both from the Uinta. 

 The distinctions between it and DaphcB7ius of the White River 

 Oligocene are especially seen in the characters of the superior 

 molars ; in Frodaphce/tJts Xho. external cusps are flanked by a broad 

 cingular ledge which anteriorly is developed into two distinct 

 cusps. The unusual extension of this ledge serves to increase the 

 transverse diameter of the tooth, especially upon its anterior bor- 

 der, and on this account it resembles 

 the corresponding tooth of Viverraviis 

 more than that of the Dogs in general. 

 Another important distinction is the 

 small development of the postero- 

 internal cusp, which in Daphanus is 

 as large as it is in the modern Canidae. M^Upper'^TeK'rowrvtewfn JuVfi 

 In the specimen under consideration pHnceton €01^''"'" ^°' "'''^' 

 the tooth is broken in such a way as 



not to show this postero-internal ledge very distinctly, but there 

 can be little doubt that it was present though small. 



Its technical distinction from Uintacyon cannot at present be 

 given on account of our lack of knowledge of the upper teeth of 

 this later genus. That it is a direct descendant of Uintacyon, and 

 the immediate forerunner oi Daphcsnus, there can be little doubt. 

 The most striking similarity to Daphcenus is seen in the low 

 rounded cusps of the molars, the absence or very small develop- 

 ment of intermediates, the reduced size of the third superior 

 premolar, as well as the molar formula above, which is 3. 



Until it can be more clearly distinguished from Uintacyon the 

 genus must be regarded as provisional only, but at the same time 

 there is little probability that the genus Uintacyon continued into 

 the Uinta without change. 



II. — The Ancestry of the Dholes. 



CvoN, Temnocvon, Daphcenus, Prodaph/Enus, Uintacyon. 

 I. Cyon and l^emnocyon. 



The Dhole or Red Dog of India {Cyon) can be confidently 

 considered as the living representative of the John Day genus 

 Temfiocyon, and through this genus is probably descended from a 



