MAMMALS—CANIDAE—LUPINAE. 103 
The incisors, canines, and first premolars, have each a single fang; the second and third 
premolars above, and all premolars and molars below, have two fangs, except the last lower 
molar, which has but one; the upper sectorial or fourth premolar and the last upper true molar, 
have three fangs; the first upper true molar has four fangs. 
The deciduous dentition of the Canidae is, incisors, =; canines, =: molars, ;—. —=283 
The chief external peculiarities of the dogs, as distinguished from the cats, are to be found in 
the long sharp muzzle, pointed erect ears, small eyes, long hair, bushy tail, contracted belly, &c. 
The entire family of the Canidae is divisible into several groups, all of the same dental 
formula, exclusive of the aberrant genus Megalotis or Otocyon, in which there are six additional 
teeth, as described. These groups may be characterized as those of the wolves and foxes, although 
the South American foxes, in reality, form a group directly intermediate between the wolf and 
fox forms of Europe and North America—a fox-like wolf. 
In the wolves the pupil is circular, the tail rather short, and the median upper incisors very 
distinctly lobed on each side. In the foxes the pupil is elliptical, the tail long and bushy, and 
the whole form more slender. But the most appreciable difference is to be found in the character 
of the post-orbital process of the frontal bone, as indicated by Burmeister. This process in the 
wolves is triangular and decidedly convex on its upper surface, rounding outwards and down- 
wards, with the point appreciably below the plane of the interorbital space. In the foxes, how- 
ever, this process is scarcely convex above, sometimes concave, the point hardly dips down at 
all, the margins particularly, the anterior of which are slightly turned up, and there is a con- 
spicuous depression or indentation along the base of this process above, where it springs from 
the frontal bone. It is an interesting fact, that all the fox-like animals of South America have 
really the wolf type of structure, not only in this respect, but in having nearly circular pupils. 
Their tails are, however, very long, exceeding even those of the true foxes, and reaching to the 
ground; and the name of Lycalopex,! as proposed by Burmeister, seems quite appropriate. To 
the wolves, probably embracing all the South American Canidae, we may assign the name of 
Lupinae, the Vulpine including all the true foxes. 
Since the preceding paragraph was written, Burmeister has subdivided the South American 
fox-like wolves into Lycalopex and Pseudalopex. 
Sus-Famity LUPINAE. 
Post-orbital process of the frontal bone very convex and curving downwards, with little or no depression or indentation in its 
upper surface, 
' Cerdocyon of Hamilton Smith, Dogs, I, 1839, 289. 
