366 University of California Publications in Geology [Vol. 7 



Creek, Nebraska, possibly belonging to late Miocene or Pliocene 

 deposits. 



A portion of a lower jaw (no. 19402), with P., to M„ inclusive, 

 from the Mohave Beds of the Mohave region, California, very 

 closely resembles the type of Leidy's Canis temerarius from the 

 Nebraska formation and also resembles the specimen from Whistle 

 Creek, Nebraska, referred to this species by Peterson. M 1 of the 



Fig. 7. Tephrocyon temerarius (Leidy). Occlusal view of teeth and 

 external view of lower jaw, natural size. (Carneg. Mus. Cat. Vert. Foss. 

 no. 2404). (After Peterson). 



Mohave specimen very nearly approaches in form and dimen- 

 sions the original figured specimen of Canis temerarius (Leidy), 

 and the Mohave species is almost identical in form and dimen- 

 sions with the corresponding parts of the specimen described 

 by Peterson. 



The specimen from Mohave Beds (figs. 8a and 8b) represents 

 a species of Tephrocyon differing slightly from those thus far 

 known in the Great Basin region. The relationship of this form 

 to the genus Tephrocyon is shown in the large size of the meta- 

 conid and of the crushing heel of M x , and in the presence of a 

 well-developed paraconid with a large antero-external shelf on 

 the cingulum of M 2 . 



The Mohave form is distinguished from Tephrocyon rurestris 

 and T. hippophagus by the smaller, more slender teeth. From 

 T. helloggi it differs in the relatively larger M ± and smaller M 2 , 

 and smaller metaconid of M r Mj in the Mohave specimen 

 measures 17 mm. in anteroposterior diameter as compared with 



