80 Bulletin American Museum of Natural History. [Vol. XXXIV, 
No. /6821,;, A.M. 
view. 
Sinopa multicuspis (Cope 1875). 
Prototomus multicuspis Copn, 1875, Syst. Cat. Vert. Eoc. New Mex., p. 10; 
(Stypolophus), 1877, Ext. Vert. New Mex., p. 116, pl. xxxix, figs. 12-14; (Sznopa), 
Marruew 1901, Bull. A. M.N.H., Vol. XIV, p. 27. 
Type, U. S. Nat. Mus. No. 1021, upper jaw, ptm’ from the New Mexican 
Wasatch. 
Distinctive characters: M3? =19 mm.; mi3=21 mm. Jaw rather short, 
premolars all two-rooted, p2, spaced. Enamel smooth, molars subequal in size, 
heels rather small. A deuterocone on p?. 
| To this species are referred a number of upper and lower jaws from the 
Lost Cabin, Lysite and Gray Bull horizons, Nos. 4782, 14773-5 from Lost 
Cabin zone, 16819-20 from upper Gray Bull or Lysite, 15239, 16156, from 
Gray Bull zone. In No. 16820 numerous fragments of the skeleton are 
associated with the upper and lower jaws. | 
Sinopa vulpecula sp. nov. 
Type, No. 15606, lower jaw from Lost Cabin horizon in Big Horn Basin, Wyoming. 
Distinctive characters: Size of S. multicuspis, but m+ relatively small, premolars 
higher, more compressed, accessory cusps smaller, jaw slender and elongate anteriorly 
with considerable diastemata before and behind p,. 
Nos. 15744, lower jaws, and 73, upper jaw fragment with m7, both 
from,the top of the Gray Bull beds in the Big Horn Basin supplement the 
