13 
This family is connected to the cats by the hyenas, of which no species 
occur in North America. Indigenous species of dogs occur in all habita- 
ble regions, and the domestic dog thrives wherever man has a foothold. 
The dogs are separated from the cats externally by the long, sharp 
muzzle, small eyes, long hair, bushy tail, contracted belly, and pointed, 
erect ears; they are related to the hyenas by the blunt, non-retractile 
claws, by their digitigrade feet, and general appearance. 
The Canide vary much in size from the largest wolves to the California 
coast fox, scarcely larger than the domestic cat. 
There are two groups or sub-families of North American Canidx, the 
wolves, including the domestic dog, and the foxes. These groups are 
related by the South American foxes—a fox-like wolf directly interme- 
diate between the fox and wolf forms of Europe and North America. 
in the wolves the tail is short, the pupil circular, and the median upper 
incisors very distinctly lobed on each side; the post-orbital process of the 
frontal bone is triangular, convex on its upper surface, with its point 
below the plane of the inter-orbital space. Sub-family Lupine. 
In the foxes the tail is bushy, the pupil elliptical, and the whole form 
more slender; the upper incisors are scarcely lobed, and the post-orbital 
process of the frontal bone bent but little downward, the anterior edge 
turned up; a longitudinal shallow pit or indentation at its base. Sub- 
family Vulpine. 3 
The South American fox-like forms (Lycalopex and Pseudalopex of Bur- 
meister) have the circular pupils and wolf-like character of the post- 
orbital process, but their tails are even larger than those of the true foxes, 
reaching to the ground. Prof. Baird, therefore, includes them in the 
sub-family Lupine. | 
KEY TO THE GENERA OF CANID. 
* Post-orbital process of the frontal bone very convex and curving downwards, with 
little or no depression or indentation in its upper surface; pupil circular; tail com- 
paratively short; upper incisors distinctly lobed on each side. . . . CANIS. 
** Post-orbital process bent but little dowuwards, the anterior edge turned up; a longi- 
tudinal shallow pit or indentation at its base; tail long and bushy: pupil ellipti- 
cal; body more slender; upper incisors scarcely lobed. 
t Tail with soft fur and long hair uniformly mixed; muzzle long; temporal crests com- 
ing nearly in contact. 0 : 5 : C : 5 6 : . VULPES. 
tt Tail with a concealed mane of stiff hairs, without soft fur intermixed ; muzzle shorter; 
temporal crests always widely separated. 6 : ; . UBOcYON. 
