16 



University of California Publications. [Geology 



In another specimen (No. 10256) consisting' of a large portion of 

 a lower jaw with P 4 and M 1? the external tubercle at the base of 

 the protoconid and the smaller one anterior to the entoconid are 

 both present. The external tubercle is, however, greatly reduced 

 by wear without the remainder of the tooth appearing much 

 worn. The dimensions of this jaw and of the heel of M x are con- 

 siderably less than those of the type of latidens, and are nearer 

 the dimensions required by lemur. These relations together with 

 the fact that the jaws described as lemur agree with Gyno- 

 dictis ( '?) oregonensis seem to indicate that the small sectorials 

 just described possibly belong to lemur, and that the presence of 

 the external tubercle on the base of the protoconid is a charac- 

 teristic of lemur as well as of latidens. 



MEASUREMENTS. 



No. No. Type spec. Type spec. 



ToTTTf '88' 



P 4 , anteroposterior diameter 6 



M 1; antero-posterior diameter 8.2 7.6 



M„ antero-posterior diameter of heel 2.8 2.8 



Depth of ramus at sectorial 8 



latidens 



lemur 



5.5 





8 



3.5 



8 

 "3 



10.5 



8 



MESOCYON CORYPHAEUS Cope. 



T emnocyon coryphaeus Cope, Proc. Philad. Acad., 1879, p. 180 ; and Ter- 

 tiary Vertebrata, p. 906. 



Mesocyon coryphaeus (Scott), Princeton College Bull. 2, No. 2, p. 38, 

 Apr., 1890. 



Hypotemnodou coryphaeus (Eyerman), Am. Geol., Vol. 14, p. 321, 1894. 



This species is represented in the collection by several crania 

 and mandibles. Specimen No. 1383 shows the complete upper 

 dentition, of which particularly the sectorial and the molars are 

 unworn and in perfect state of preservation. In No. 1165 the 

 upper dentition is complete excepting the incisors. Both of these 

 specimens agree with Cope's type very closely in their measure- 

 ments. Another cranium (No. 1692) representing the genus 

 Mesocyon differs from both M. coryphaeus and M. josephi, and 

 has been made the type of a new species described below. 



3 According to Cope 's figure, Tert. Vert., PI. 70, Fig. 7a. 



