N-o.s.] COPE ON EOCENE VERTEBRATA OF WIND RIVER. 187 



15. Pelycodus jarrovii Cope. 



A jaw fragment supporting the last two molars presents the charac- 

 ters and dimensions of this species. The genus Pelycodus differs from 

 Tomitherium in that the second premolar resembles the later ones in 

 having two roots instead of having but one root like the first, as is found 

 in the latter genus. 



16. Pelycodus tutus Cope. 



Tomitherium tutum Cope, Report Expl. Surv. W. of lOOth Mer. under Capt» 

 Wheeler, iv, pt. ii, p. 141. 



Eepresented by numerous specimens. 



17. Pelycodus nunienum sp. nov. 



Fragmentary jaws of six individuals of this species were found by 

 Mr. Wortman. They indicate a species intermediate in dimensions be- 

 tween the P. tutus and P. frugivorus, which is further defined by the 

 form of the last inferior molar. 



The best preserved ramus supports all the teeth posterior to and in- 

 cluding the third premolar. The last-mentioned tooth has an elevated 

 acute crown, without any anterior basal tubercle, and a very short pos- 

 terior heel. The fourth premolar is very stout ; its cusps are not much 

 elevated, and the heel is short. The anterior basal tubercle is quite 

 small. All of the true molars have a second cusp in front of the anterior 

 interval, but it is quite small, excepting on the first, where it is more 

 distinct. The external crescents of all the molars are well defined, but 

 the posterior does not inclose the crown behind with an extension of its- 

 horn. The last molar is a little longer than the others, and its posterior 

 border is produced into two cusps. A simple raised border is found here- 

 in P. frugivorus. 



Measurements. 



M. 



Lengtli of molar series from third premolar, inclusive 0228- 



Length of true molars 0150 



( anteroposterior 005O 



Diameters ol first true molar J ^^^^g^g^g^ ^,033 



( anteroposterior 0065 



Diameters of last true molar J ^^g^g^^^g^ ^^^^^ 



Depth of ramus at Pm. Ill 0095 



Depth of ramus at last true molar 0095 



18. Pantolestes secans sp. nov. 



Eepresented by the adherent rami of a mandible, on both of which 

 the posterior four molar teeth are preserved. 



The species is about the size of the P. chacensis, and hence larger than 

 the P. longicaudus. It differs from both in the proportions of its teeth^ 

 and especially in the large size and sectorial character of the fourth pre- 

 molar. The length of the latter exceeds a little that of the third true 

 molar, while in the other species it is shorter. This length is caused by 

 the extent of the anterior basal tubercle and posterior heel. The latter 



