36 Bulletin American Museum of Natural History. [Vol. XXXIV, 
specimen is known from the Wind River, Nos. 15177-8 from the Gray Bull 
may be a primitive mutant of this species. The second molar in this mutant 
is somewhat larger and more like the first in pattern. 
Other species of Miacis are represented by fragmentary specimens from 
the Big Horn Basin and the New Mexican Wasatch, but they are inade- 
quate for specific types. 
Fig. 30. Miacis latidens, upper and lower jaw with molar teeth, m'~2, mz-3, enlarged to 
two diameters, with outline of natural size. Type specimen, Lost Cabin beds, Wind River 
Basin. 
Vulpavus Marsh 1871. 
Type, V. palustris, from the Lower Bridger of Wyoming. 
T'wo Lower Eocene species are referable to this genus. As compared 
1 Amer. Journ. Sci., Vol. II, p. 124. 
