124 University of California Publications in Geology [Vol. 10 



specimens from the Barstow Miocene. It differs from Barstow speci- 

 mens in its slightly less prominent tuberosity, and in the situation of 

 the posterior facet for the navicular somewhat nearer the proximal 

 end of the element. In these particulars the Tejon Hills specimen 

 approaches more closely the characters of an equid cuboid from the 

 Ricardo Pliocene. 



At locality 2751, in which the small equid metapodials, the 

 phalanx, and the cuboid were found, no Merychippus teeth are known, 



but a number of Neohipparion teeth occurring there show dimensions 

 not greater than those of the smallest Merychippus forms of the Bar- 

 stow. It is therefore possible that the Merychippus-like limb elements 

 represent the little Neohipparion species, in which resemblance to 

 Merychippus is especially strong because small size has made unneces- 

 sary certain peculiar specializations in structure found in the larger 

 and perhaps more nearly typical species of the genus. . 



