240 On the Extinct Dogs of North America.  [March, 
the numerous species from these epochs is not yet known, and, 
therefore some doubt as to their correct generic reference may 
still exist, I only regard the genus as a certain inhabitant of North 
America during the John Day, or Middle Miocene, epoch. This 
is indicated by the Galecynus geismarianus, where the number of 
the toes on the posterior foot has been ascertained (Fig. 6). 
All the species of the genus from Eocene and Lower Miocene 
beds, as well as most of 
those of the Loup Fork 
epoch, are characterized by 
the relatively small size of 
their sectorial teeth? In — 
this they resemble the Am — 
phicyons, Temnocyons and 
other forms of Canidae of 
the same period, and differ — 
from such Canes as C ür- 
Fic. 5.—Galecynus geismarianus Cope,one- , whi 
half nat. size, skull from side and below, sinus and C. haydent, which l 
From John Day beds,. Oregon, Original. display the enlarged sec- : 
torial teeth of the existing species of the genus. Of cours 
there is every gradation in this respect between the two typ 
In the older species the internal tubercle of the inferior sectorial 
tooth is more largely developed than in the latter ones, thus ; 
Professor Owen proposed to distinguish the genus Galecy 
account of the greater length of the pollex as compar 
that found in the existing species of Canis. This charac H 
pears to me to be of an unsatisfactory nature, owing tO the 
1 See Bulletin U. S. Geol. Survey of the Terrs., F. V. Hayden, Vol. Vh sei 
180. 
