1915.; Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. vat 
Viverravus Marsh 1872.1 
Type, V. gracilis from Lower Bridger of Wyoming. 
Syn., Didymictis Cors, in part. 
This genus is represented in the Lost Cabin and Lysite beds by V. 
dawkinstanus (Cope), in the Sand Coulée and Gray Bull by two undescribed 
species with premolars very like those of Miacis. The successive species 
from Sand Coulée to Bridger show a progressive elongation of the premolar 
region of the jaw and lengthening of the premolars. V. dawkinsianus is 
close to gracilis; the two older species are much more primitive. No 
notable change occurs in the molar teeth. 
MAG. 
YS ain: 
AW 3 
Fig. 20. Hig; 23% 
Fig. 20. Viverravus, lower jaws of three species of the Lower Eocene. Above, V. 
dawkinsianus, Lost Cabin zone, middle figure V. acutus, lower figure V. politus, both Sand 
Coulée and lower Gray Bull zone. All natural size. : 
Fig. 21. Viverravus acutus, lower jaw, inner and outer views and crown view of teeth, 
+wice natural size, with outline of natural size. Type specimen, Sand Coulée beds, Clark 
Fork Basin. 
Viverravus acutus sp. nov. 
Type, A. M. No. 16112, parts of lower jaws and fragments of upper jaws from 
Sand Coulée beds, Clark Fork, Wyoming. 
1 Amer. Jour. Sci., Vol. IV, p. 127. 
