EPIHIPPUS. 



689 



Epihippus, which made a further approach to the 

 horse type, in having the 2nd premolar more hke a 



Fore 

 foot. 



Hind 

 foot. 



Radius Tibia 

 and and 

 ulna, fibula. 



Upper molar. 



Lower 

 molar. 



Recent. 



Equus. 



Pliocene. 



Pliohippus. 



I'rotohippus. 



Miocene. 



Miohippus. 



Mesohippus. 



Eocene. 



Orohippus. 



Fig. 643. — Evolution of the bones of the legs, below the elbow and stifle, and 

 molar teeth of the horse. {After Marsh). The fossil remains of Eohippus were 

 found, after Professor Marsh had made this table. 



molar than was the case in Orohippus, was found in the 

 Upper Eocene of Wyoming. As in Orohippus, the 3rd 



44 



