PLATE 22 



TYPES OF THREE SPECIES OF PROTOHIPPUS. 



All figures natural size. 



Republican River, Driftwood Creek, Nebr. Lower Pliocene 

 Little White River, So. Dak. 



Republican River, Nebr. " " 



1. Protohippus secundus Osborn, type, Am. Mus. 8340. 



2. P. perditus simus Gidley, paratype, Am. Mus. 10871. 



A portion of the upper jaw containing all the large 

 cheek teeth except m 1 . 



3. P. profectvs Cope, type, Am. Mus. 8349. Six isolated 

 . superior molar teeth of the left side. 



266 



