Douglass : Vertebrates from Montana '1'ertiary. 171 



REPTILIA. 



0(;mophus arenarum sp. nov. 

 No. 744. 



Three vertebrcX of a snake from the Flint Creek beds, were asso- 

 ciated with many small bones and teeth, among which were the hum- 

 eri of moles described in this paper. 



The vertebrre not so long as broad. Centrum small, with no keel 

 but a broad convexity on lower side. Ball transversely elliptical and 

 facing somewhat upward as well as forward ; neural canal arch-shaped 

 with a median ridge or convexity on floor ; the articular surfaces of 

 the zygapophyses horizontal ; articular surfaces of the zygosphenes 

 quite narrow and facing outward and downward ; neural spine low 

 and not reaching to the anterior part of the neural arch ; neural arch 

 large and zygosphenes almost as far apart as its width ; protuber- 

 ance for articulation of the rib quite prominent, higher than wide, 

 convex above and in front, and slightly concave on the posterior in- 

 ferior surface. The interzygapophyseal ridges almost die out midway 

 between the anterior and posterior zygapophyses. 



Compared with O. tvigulattis Coi)e (Tert. Vert., p. 783, PI. LVIILr, 

 Fig. 13) the protuberance for the articulation of the rib is larger, the 

 vertebra proportionally lower, and there is no hypophyseal angle or 



ridge. 



Measurements. 



Mm. 



Length of centrum of vertebra 4 



Width of vertebra 5 



MAMMALIA. 

 INSFXTIVORA. 



Talfa? platybrachys sp. nov. 



Type No. 728. Fig. 13. 



In the same beds as the preceding (No. 744), associated with scat- 

 tered teeth and bones of rodents and other small animals, four humeri 

 of moles were found belonging to the same or closely related species. 

 One of these is nearly complete and I take it as the type of the 

 species. 



The humerus is smaller than the corresponding bone of Scalops 

 aquaticus. It differs from it in having a narrower shaft, in this respect 



