1913] 



Merriam: New Protohippine Horses 



441 



sent a type related to Neohipparion, but are probably to be 

 included in Protohippus or Pliohippus. Several much worn 

 upper molars from the Ricardo region seem clearly of an ad- 

 vanced Protohippus or Pliohippus type, and may represent the 

 same species as the type of P. tantalus. 



Figs. 4a and 4b. Protohippus ( ? ) tantalus, n. sp. P 4 (?). No. 19434, 

 natural size. Late Tertiary near Ricardo, California. Fig. 4a, occlusal 

 view; fig. 4b, outer view. 



Measurements of No. 19434 



P 4 ?, anteroposterior diameter 



P 4 ?, transverse diameter 



P 4 '?, height of crown 



24.8 mm. 



24 



48 



Transmitted December 15, 1913. 



