1913] Merriam: New Protoliippine Horses 



437 



the height of upper cheek-tooth crowns may equal about twice 

 the transverse diameter. The transverse diameter of the anterior 

 molars and posterior premolars about equals or slightly exceeds 

 the anteroposterior diameter. The cement layer is well developed 

 on the outer and inner sides. The parastyle and mesostyle are 

 prominent. The external rib formed by the mesostyle is especi- 



la 2a 3a 



Figs, la to 35. Kipparionf ? ) mohavense, n. sp. Upper cheek-teeth. No. 

 19787, natural size. Late Tertiary near Kicardo, California. Tigs, la and 

 16, M 2 ; fig. la, occlusal view; fig. lb, outer view. Pigs. 2a and 26, M 1 ; 

 fig. 2a, occlusal view; fig. 2b, outer view. Figs. 3a and 3b, P 3 ; fig. 3a, 

 occlusal view; fig. 36, outer view. 



ally strong on the premolars. It narrows very gradually from 

 the base. The middle region of the outer sides of the paracone 

 and metacone crescents is flat, but may show a slight tendency to 

 formation of a median rib. 



The small protocone is free almost to the base in most 

 specimens. In cross-section it is nearly circular or is slightly 

 elongated anteroposteriorly. The walls of the anterior and 

 posterior fossettes show unusually numerous plications. The 

 posterior wall of the prefossette and the anterior wall of the 



