158 Annals of the Carnegie Museum. 



assume the molar pattern. There are internal cingula on the last two 

 premolars. The lower teeth are much like those of H. agraiius. 



The atlas is much like that of Protapirus validiis. The concavity 

 for the odontoid process of the axis is much narrower, indicating a 

 thick, conical odontoid. The posterior cotyles are wider dorso- 

 ventrally, the lower part is longer antero-posteriorly on the median 

 line, and there is quite a large protuberance on the ventral posterior 

 border, projecting backward. 



Measurements. 



Mm. 



Width of palate between second premolars 38 



Length of I- 8 



Width of 12 5 



Length of premolar series 46.5 



Length of PL 10 



Width of Pi 7 



Length of P- 9.7 



Width of P^ 12 



Length of P^ 13 



Width of P^ 18.6 



Length of P^^ 19.5 



WidthcfP* 22 



Length of mandible about 250 



Width " at symphysis, narrowest 26 



Depth " mider Pl 38 



Depth " under M^ 47 



Length of inferior molar-premolar series 98 



From same locality as the preceding. 



Hyrachyus. 

 No. 718. Fig. 3. 

 Represented by a solitary last upper molar found 

 about a half mile from HeptodoJi (No. 717) and Hyra- 

 cliyiis pn'sci/s (No. 784) described in this paper. It 

 "hm resembles the corresponding tooth of Hyrachyus inter- 

 FiG 1 Ilvra- I'ledms (Princeton collection. No. 10,095). The ante- 

 c hy us? N o. rior cross-crest is more nearly straight, and being broader 

 718. Crown at the base, makes the median transverse valley more 

 view of last narrow. The anterior inner cusp is more conical. 



"^^"^ The anterior outer style (parastyle) is not so much 

 molar. Sage 

 Creek beds * external to the anterior outer cusp. The posterior 



nat. size. Outer cusp (metacone) is small, thin, laterally com- 



