PROTOHIPPUS. 



137 



Fig. 109. (Upper) Type of Protohippus simus Gidley, Amer. Mus. 9820. Lateral view of skull, crown view of 

 superior grinding series of the right side. Drawings by B. Yoshihara. (Lower) Protohippus simus Gidley, Amer. Mus. 

 10871, superior grinding teeth of the paratype, of the left side. Skull one-half natural size, teeth natural size. 



