1883.] On the Extinct Dogs of North America. 243 
of Colorado. It is uncertain whether this genus has two or 
three premolars. Should it have three it must be compared with 
the Brachycyon of Filhol. But the inferior sectorial tooth of that 
genus is as yet unknown. In Tomarctus it is like that of Canis 
and AZlurodon. The T. drevirosiris has teeth as large as those of 
a coyote, but has the lower jaw shorter and more slender. 
AELURODON Leidy. 
Dr. Leidy described an 4lurodon ferox, whose affinities he did 
not determine, but which he thought to combine characters of 
Fic. 9 —lurodon sev i i i 
us Leidy, skull three-eighths nat. size. From the Loup 
Fork beds of Nebraska. Original. r 
lo Ss and cats. I have proven! by material in my possession, that 
xe Elurodon ferox and the Canis sevus Leidy, are the same spe- - 
“es. The genus Ælurodon must be referred to the Canidz, and 
E ES 
Bulletin U.S, Geolog. Survey Terrs., v1, 1881, p. 387- 
