292 E. L. Troxell — Status of Homogalax. 



Summary. 



Systemodon Cope, an indefinite genus concerning which 

 there is some confusion, is considered for the present, fol- 

 lowing "Wortman, as a synonym of Hyracotherium Owen, 

 but it is evident from the present study that both are dis- 

 tinct from Eohippus Marsh. 



Homogalax primcevus (Wortman) Hay is a species of 

 tapiroids about the size of Hyrachyus agrarius Leidy; 

 but it may be easily separated from this and from the 

 early horses by the absence of diastemata, by the exist- 

 ence of a third lobe on the last lower molar, and by other 

 generalized features. There is no evidence of a facial 

 depression like that of Helaletes. 



Two new species are here proposed: Homogalax 

 bridgerensis and H. uintensis; these, together with H. 

 primcevus, the genoholotype, represent three localities 

 distinct geologically and geographically. H. bridgerensis 

 may be distinguished by the triangular P 3 with distinct 

 metaloph, the small canine, the absence of diastema and 

 the geological age. H. uintensis is notable for its larger 

 rounded teeth, double parastyle and late Eocene age. 



Measurements. 



H. bridgerensis H. uintensis 



12563, Y.P.M. 12561, Y.P.M. 



mm. mm. 

 Upper dentition 

 Length of molar-premolar series .... 68 



Length of molar series 38 44.5 



Lower dentition 



Length of P 3 to M 3 inc 58.3 68.3 



Length of molar series 41 47.3 



