1915.] Matthew and Granger, Lower EKocene Wasatch and Wind River Faunas. oY 
with the Middle Eocene species they retain considerably more of the tuber- 
culo-sectorial character of the molars. This is most marked in the speci- 
Fig. 31. Lower Eocene species of Vulpavus, lower jaws, natural size. Above, V. cana- 
vus, Nos. 14760 and 14767, Lost Cabin beds, Wind River basin; below V. australis, No. 
16226 and 16227, Largo beds, San Juan Basin. 
mens from the Gray Bull horizon; in the Lysite and Lost Cabin specimens 
it progressively disappears. 
Vulpavus canavus (Cope 1881). 
Miacis canavus Corr, 1881, Bull. U. 8. G. S. Terrs. Vol. VI, p. 189; 1885, Ter- 
tiary Vertebrata, p. 302; Uintacyon Wortman, 1899, Bull. A. MM Ned, Vou. X11, 
p. 112; (Prodaphenus) Worrman 1901, Am. Jour. Scli., Vol. XI, p. 30; (Vulpavus) 
Marruew 1909, Mem. A. M. N.H., Vol. VI, p. 380. 
Miacis brevirostris Corn, 1881, I. c., p. 190; 1885, 1. c., p. 303; Wortman, 1899, 
‘ey 3 | 
Type, Am. Mus. No. 4783, a lower. jaw with teeth broken off, from Lost Cabin 
beds of Wind River Basin. 
Type of M. brevirostris, Am. Mus. No. 4785, a lower jaw with m, and part of pu, 
other teeth broken off, from same horizon and locality. . 
Distinctive characters: M,-3 = 19-20 mm., pi-m3; = 36-41 mm. Lower tubercu- 
lar molars large; m, imperfectly carnassiform; ms two-rooted; heels of mi_2 as wide 
and as long as trigonids. Premolars reduced and spaced, slight accessory cusp on pa. 
Jaw short, deep and heavy, canine large, not compressed. 
