Am. Jour. Sci., Vol. XXXVII, Feb., 1914. 



Plate VI. 



Fig. 1. Skull of Parahipparion sp., from Ayusbamba, lateral view, x 0*18. 

 Fig. 2. Skull of Onohippidium compressidens in the Museum of La Plata, after 

 Lydekker. x O'lo. 



Fig. 8. Skull of Parahipparion sp., from Ayusbamba, posterior view, x 0"25. 



