SUB-ORDER. 
CARNIVORA. 
Incisors six in each jaw ; the lateral ones largest. Canines distinct, conical. Clavicles imperfect or wanting. 
The above phrase characterizes the great division of the Carnivora as to its essential points. 
The Insectivora, to which they are closely allied, have the central incisors as large or larger 
than the lateral; the canines less distinct; the clavicles perfect. There are many other features, 
however, in which the Carnivora exhibit their claim to a separate subdivision of the animal 
kingdom. 
Osteologically the Carnivora are characterized by the fact that the clavicles are either want¬ 
ing or else quite rudimentary. There are six incisors in each jaw, the outer the largest. There 
is a distinct canine on each side of each jaw, just behind the incisors; they are generally very 
large, conical, and deeply implanted by a single fang (in the upper jaw just behind the inter¬ 
maxillary). The incisors and canines vary hut little, comparatively, in the different genera 
and families. The molars, on the contrary, differ very much as to number and shape. In this 
character is a striking difference from the Insectivora , where, with a nearly constant type of 
molars, the canines and incisors differ exceedingly. 
As a general rule it is the premolars of the Carnivora which play the most important part in 
the series of cheek teeth. In nearly all of the families, one of these on each side, in each jaw, 
is so arranged with compressed and cutting crowns, that those of opposite jaws, on either side, 
play against each other and serve to divide the food like a pair of shears. Others have, either 
in addition to, or instead of this arrangement, molars with tuberculous crowns for more readily 
crushing hones or other hard substances. Immediately behind each canine are one or more 
comparatively small teeth, with conical or compressed crowns, and simple or double fangs. 
These are often absorbed or wanting in age. Next come the sectorial teeth, as described above. 
Behind the sectorial teeth are one or more teeth with tubercular crowns. The habits of the 
species depend much on the relative number and development of these two kinds of molars, 
whether trenchant or tuberculous ; when the former predominate, the food is more exclusively 
the flesh of animals, while the opposite condition indicates sustenance of a more mixed nature. 
The order of Carnivora is usually divided into six families: the Felidae , Hyaenidae , Canidae, 
Viverridae, Mustelidae, and Ursidae. Of all these, North America possesses representatives, 
excepting the Hyaenidae. Of the Viverridae there is hut one genus known in America, namely, 
Bassaris. At one time it was believed that fossil remains of Hyaenidae occurred in the bone 
caverns of Brazil; these are now with more probability referred to a genus Smilodon, very 
closely allied to, if not identical with, Machairodus , an extinct genus of Felidae , first discovered 
in Europe, hut recently shown by Dr. Leidy to exist in the Mauvaises Terres of Nebraska. 
The North American families may he grouped as follows: 
A. DIGrITIGrRADE. Hinder feet with four toes. 
Felidae. 
Canidae. 
