eee en ee 
See ee a 
1883. | On the Extinct Dogs of North America. 241 
that gradations in the length of a digit are difficult to express 
with precision in other than a specific sense; and the gradations 
may certainly be expected to occur. 
I find in the G. getsmarianus a character which separates the 
genus from Canis, viz., the presence of the epitrochlear foramen 
of the humerus. In this point it agrees with Amphicyon and 
Temnocyon. I arrange cotemporary and generally similar spe- 
cies under the same generic head, as the most reasonable course 
in the absence of direct evidence. 
I know four species of Galecynus from American localities. 
These are, in the order of size, beginning with the largest. G. 
Fic. 6.—Part of skeleton of one individual of Galecynus geismarianus, one-half 
hal. size; from the John Day bed of Oregon; a, vertebral column with pelvis; 4, 
axis vertebra; c, elbow, showing epitrochlear foramen ; d, metatarsus and phalanges ; 
¢, tarsus, showing grooved astragalus. Original. 
geismarianus Cope (Figs. 5-6), G. latidens Cope, G. gregarius 
Ope, and G. /emur Cope (Fig. 7). Threé of these are confined 
to the John Day Miocene, while the G. gregarius is abundant in 
the White River formation of Colorado and Dakota. The G. 
é*smarianus (Figs. 5-6), is a little smaller than the gray fox 
(Vi ulpes virginianus), and had a more civet-like form. That is, 
the body was relatively longer and the limbs shorter. The G. 
lems (Fig. 7) is remarkable for its very large orbits and otic bul- 
æ. These indicate large eyes and large ears, and render it prob- 
able that the animal was nocturnal in its habits. These, with its 
