1915.| Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. 15 
ments of skull and skeleton show the dentition well preserved. The species 
appears to be related through S. hians and T. whitie to the Tritemnodons of 
the Bridger formation. 
Nos. 4782, 14773-5, upper and lower jaws from the Lost Cabin horizon 
— 
Fig. 66. Sinopa strenua, front of skull and lower jaw, natural size. No. 15234, upper 
Gray Bull beds, Big Horn Basin. 
of the Wind River, agree in most respects with the Gray Bull specimens 
and with the type of the species, but are somewhat smaller and the meta- 
cone of m* vestigial while it is distinct in the Gray Bull form. 
Fig. 67. Sinopa strenua, upper and lower dentition, crown views, natural size. From 
No. 15234. 
Sinopa hians (Cope 1877). 
Stypolophus hians Copx 1877, Ext. Vert. New Mex., p. 72, pl. xxxvili, figs. 12-30; 
(Sinopa) Marraew 1901, Bull. A. M. N. H., Vol. XIV, p. 25 (in part). 
Type, U.S. Nat. Mus. No. 1111, numerous fragments of skeleton in bad preserva- 
tion. 
