536 



CENOZOIC ERA— AGE OF MAMMALS. 



Fig. 915.— Brontops, restored by Marsh, x 3 V 



Nebraska to Oregon. Thirty-five species of Oredontidae are known, 

 although not all from this horizon. The head of one is given below 

 (Fig. 916). 



Fig. 916.— Oreodon Culbertsoni (after Gaudry). 



The Miocene of Oregon — John Day basin — is equally rich in re- 

 mains of all the families mentioned above. Among Carnivores, besides 

 many species of the Cat family, Cope has described ten species of the 

 Dog family. 



It is well to note that in the Miocene, for the first time, existing 

 families of mammals began to appear. We have here the families of 

 the dog, the cat, the deer, the camel, the horse, and the rhinoceros. It 



