Wortman — Studies of Eocene Mammalia^ etc. 17 



96 



Akt. IY. — Studies of Eocene Mammalia in the Marsh 

 Collection., Peabody Museum y by J. L. Wortmak. 



[Continued from vol. xiii, p. 448.] 



Sinopa minor sp. no v. 

 A SMALLER species is represented in the Marsh collection by 

 numerous remains, all in a somewhat fragmentary condition. 

 Of these, I select as 

 the type a consider- 

 able portion of a man- 

 dibular ramus of the 

 right side, contain- 

 ing the three pos- 

 terior premolars and 

 the first and second 

 molars in place, fig- 

 ure 96 There is also Figure 96. — Right lower jaw of Sinopa minor 

 the 'anterior part of Wortman; side view; natural size. (Type.) 

 the opposite ramus, which contains the root of the canine and 

 those of the anterior premolars. With this, I associate as a 

 cotype a fragment of a right upper jaw bearing the fourth 

 premolar and first molar, figure 97. The 

 characters of this species, as exhibited by 

 the type and cotype, are as follows : The 

 size is much smaller than either S. rapax or 

 S. gracilis / the canine is of the usual pro- 

 portions ; the small single-rooted first pre- 

 molar is implanted some distance behind the 

 canine, and is separated from it and the 

 second premolar by considerable diastemata; Wortman"; crown 

 the second premolar is two-rooted and sepa- ^^®^ ' natural size. 

 rated from the third by a short inter \^al, ^ ° -^^^'^ 

 diif ering in this respect from both S. rajxtx and S. gracilis ; 

 the third and fourth premolars have the usual form ; the first 

 molar is relatively small, with low trigon and a large basin- 

 shaped heel ; the second molar is larger, with high trigon and 

 large heel ; the internal cusps are but little reduced, differing 

 in this respect from S. gracilis and agreeing with S. rapax ; 

 the last molar is not preserved in the type ; the fourth superior 

 premolar is like that of 8. gracilis^ except that the internal 

 cusp is more conical ; the postero-external blade exhibits 

 faint traces of a bilobed condition, w-hich is not seen in S. 

 gracilis ; the two main external cusps of the first molar are 

 well separated ; there is a more distinct posterior intermediate, 

 and an internal cingulum, all of wliich are different from S. 

 gracilis. 



Am. Jour. Scl— Fourth Series, Yol. XIY, No. 79.— July, 1902. 

 2 



Figure 97. — Frag- 

 ment of a right upper 

 jaw of Sinopa minor 



