1916] Buwalda: Miocene Mammalian Faunas from Tehachapi Pass 79 



Leidy": "Inner conules (pr and hy) smaller than median conules 

 (pi and ml), protoconule semi-crescentic ; partially or completely 

 united with the metaloph.; ..." 



The lower cheek-teeth of this equid form are all of one type, char- 

 acterized by being distinctly hypsodont, and well cemented. Their 

 length is approximately one to one and one-half times their antero- 

 posterior diameter. The metaconid-metastylid column is well devel- 

 oped. The marked groove between the metaconid and metastylid per- 

 sists nearly to the base of the tooth. The lower cheek-teeth seem in 

 some respects more advanced than the upper, but certainly represent 

 the same form, as the upper and lower teeth of the same individual 

 have been found together. 



In one specimen (no. 21692) lower milk teeth are present in the 

 jaw with the permanent teeth. The deciduous teeth are of the short- 

 crowned type and bear a thin cement layer. 



With the horse teeth are three astragali and scattered litnb bones 

 representing small forms. One of the three astragali is much smaller 

 than the others and possibly represents a type distinct from that 

 indicated by the other material. 



The camels of the Phillips Ranch fauna are known from cheek- 

 teeth, an astragalus, a distal portion of a radius, a distal portion of a 

 tibia, and by a number of foot bones. The material probably does not 

 permit of specific determination, but difference in the size of the teeth 

 suggests that a large and a small species of camel are present. 



Moropus is indicated in the assemblage of species by a portion of 

 a lower jaw containing three premolars and a molar, all little worn. 

 Compared with Moropus elatus Marsh, the teeth in this jaw are con- 

 siderably smaller and are relatively narrower transversely. 



An incomplete calcaneum closely resembles that of the antelope- 

 like Merycodus. 



A toothless carnivore jaw represents a small form which is probably 

 not generically determinable. 



A part of a lower jaw, probably of a canid, and a portion of a tooth, 

 apparently a felid, likewise do not admit of exact identification. 



The evidence as to age of the Phillips Ranch fauna is furnished 

 principally by the horse material. The Merychippus is possibly so 

 primitive that it should be set off as a new subgenus. Merychippus 

 is usually held to range from middle Miocene to early Pliocene. It 

 appears that this faunal stage is not younger than middle Miocene and 

 may represent a somewhat earlier stage of that period. 



