PLATE III. 



LOUP FORK EPOCH. 



Figure 1. Portion of skull of Protohippus pachyops, Cope, type; left side; one- 

 half natural size. 



Figure 2. Tetrahelodon serridens cimarronis, Cope; last inferior true molar of 

 left side, one-half natural size, from above. 



Figure 3. Same as figure 2. from inner side. 



[96] 



