1883. | ` On the Extinct Dogs of North America. 237 
Ampuicyon Lartet. 
Much is yet to be desired in the elucidation of the characters 
of this genus, especially of the American forms, which are less 
abundant and of smaller size than those of Europe. The typical 
species, Amphicyon major Blv., was the largest, equaling a bear in 
size. It is derived from the i —_ 
Miocene of Sansan, France, = 
and a smaller form of it is 
found, according to Pomel, 
at San Gerand-le-Puy. Other 
species are derived from the 
latter locality, and all are 
typical of the Miocene forma- 
tion in Europe. In the “ Mio- 
pliocene” of India, a single 
species has been discovered, 
the A. paleindicus of Lydek- 
ker. The species occur in 
the Lower and Middle Mio- 
cene of North America, the 
largest of which about equals 
the wolf in size. On account 
of the large development of 
the inferior tubercular teeth, F1s.1.—Amphicyon cuspigerus Cope, with the 
I have suspected that the Taree views of skull; ‘From the Joho Day 
Canis ursinus Cope, from the beds of Oregon. Original. 
Loup Fork group of New Mexico, would prove to be an Amphi- 
cyon. If so, it is the only representative of this genus in our 
Upper Miocene. 
The three American species differ as follows: The A. cuspi- 
gerus! is small, not exceeding the kit-fox in dimensions. The A. 
rtshornianus is about the size of the coyote, and has rather 
small tubercular molars, especially of the lower series. The A. 
vetus Leidy, is a little larger, but has the tubercular molars dis- 
Proportionately larger than those of the A. hartshornianus. 
TEmNocyon Cope. 
The characters on which I rely at present for the discrimination 
of this genus from Canis are two. The first is the presence of 
a cutting edge on the superior face of the heel of the inferior sec- 
Amphicyon entoplychi is the same, 
