Douglass : Vertebrates from Montana Tertiary. 



175 



dental formula I,,, C, , 1\, M^- Premolars t, and 3 simple conical 

 cusps. M .. with a heel composed of several small cusps. 



Hesperhys vagrans sp. nov. 

 No. 748. Fig. 17. 



The type of the genus and species is a large portion of a lower jaw 

 exclusive of the ascending rami. It was associated with the bones of 

 Procamcliis in the Flint Creek beds. There are also son"te fragments 

 of the skull. 



1 2 is large and chisel-shaped. Near the root* its antero-posterior is 

 much greater than its transverse diameter. On its anterior face it is 

 convex and on its posterior face concave with a median longitudinal 



I'"lG. 17. Hesperhys vagr,nis (\u. 74S), I'lint Creek beds, \ natural size, (rt) 

 Right ramus of mandible. Partly restored from the other side. (iJ) Crown view of 

 teeth of the same. All the lower teeth are represented except the first incisor. 



convexity. I3 is low-crowned, conical, with a prominent inner cin- 

 gulum. The canine is three-sided, the posterior side being nearly 

 flat. It is slightly curving and points outward more than forward. 

 Pj and Pg are high pointed, simple conical cusps with heavy cingula. 

 P3 is much larger than P2. In P^ the anterior portion is partly di- 

 vided as if another large cusp had grown up outside of the protoconid. 

 There is also a heel, but the tooth is not at all molariform. All the 

 molars have four ]:)rincipal tubercles, but by the addition of inter- 



