64 



University of California Publications. [Geology 



persistent, and its occurrence in the John Day would not neces- 

 sarily indicate Oligocene age. 



In the Loup Fork, the species of true Felis and of Machae- 

 rodus represent a more advanced stage of development and a 

 closer approximation to the recent fauna than is found in either 

 the John Day or White River. 



Conclusions. — Taken together, the Canidae and Felidae of the 

 John Day represent a stage of evolution somewhat more ad- 

 vanced than that reached in the White River and less advanced 

 than that of the Loup Fork. Compared with the known faunas 

 of Europe, they appear to be not older than the middle Oligocene 

 of Fontainbleau and not as young as the middle Miocene of 

 Sansan. 



Issued November 30, 1906. 



