MAMMALS CANIDAE LUP1NAE. 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, ^ = 28. 



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 maybe 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, 1 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 Vulpince including all the true foxes. 



Since the preceding paragraph was written, Burmeister has subdivided the South American 

 fox-like wolves into Lycalopex and Pseudalopex. 



SUB-FAMILY LUPINAE. 



Post-orbital process of the frontal bone very convex and curving downwards, with little or no depression or indentation in its 

 upper surface. 



1 Cerdocyan of Hamilton Smith, Dogs, I, 1839, 289. 



