FAMILY. 
CANIDAE. 
Fam. Ch.—D igitigrade carnivora without retractile claws. Feet apparently all four-toed, the foremost ones, however, 
with a rudimentary thumb high up, to which a claw is attached, (sometimes wanting.) Molars !^, or more. 
Of that family of the Carnivora which immediately succeeds the Felidae , namely, the 
Hyaenidae, North America has no representatives. In general appearance the hyenas resemble 
the dogs most closely—like them, having blunt and non-retractile claws, with the anterior feet 
really four-toed. In this respect they differ from both the cats and dogs, and agree with them 
in being digitigrade. The dentition in number and shape of teeth is intermediate between the 
two, the formula being—incisors, canines, ^ ; premolars, molars, ^]=34. There is 
hut one tubercular molar above behind the sectorial, and none below. The numerical difference 
in dental formula between the hyenas and cats is in the existence, in the former, of an addi¬ 
tional premolar on each side of each jaw. 
The family of dogs is equally well marked with that of the cats, and like it, is distributed all 
over the surface of the globe. Indigenous species occur in all habitable latitudes, and the 
domestic dog lives and thrives wherever man has obtained a foothold. 
The dogs in many respects resemble the hyenas more than the cats—like the former, being 
without retractile claws. The teeth are, however, more numerous, the normal formula consist¬ 
ing of—incisors,^; canines, ^; premolars, molars, = 42. In one group, however, 
Megalotis, (Agrodius of Ham. Smith,) there is a still greater number of teeth, in the addition of 
two true molars above, and one below on each side of the jaw. 
In size the Canidae vary considerably, from the largest wolves to the small Fennec, ( Canis 
zerda of authors.) This, however, is scarcely exceeded by the diminutive Vulpes littoralis of 
the doast of California, which is hardly larger than a house-cat. 
The chief characteristics of the teeth of the Canidae , as summed up by Owen, are as follows: 
The incisors are in a series forming the segment of a circle, and increase progressively in size 
from the first to the third or outer one ; the trenchant margin of the crown is divided by two 
notches into a large middle and two lateral lobes, the inner lobe being obsolete in the external 
incisor. The premolars have strong sub-compressed conical crowns, gradually enlarging pos¬ 
teriorly and acquiring one or two accessory posterior lobes with the increase in size. The fourth 
upper premolar is the sectorial tooth, and is much larger than the one anterior to it; its blade 
is divided into two cones by a wide notch, the anterior cone being strongest and most produced. 
The tubercle is developed from the inner side of the base of this lobe. The first and second 
upper molars are tuberculate, each supports two external cusps and a broad internal basal sub- 
tuberculate talon; the second molar is less than half the size of the first. The first true molar 
below is the sectorial one; the blade is divided by a vertical linear fissure into two cones, the 
posterior the largest; behind this the base of the crown extends into a broad quadrate tuberculate 
talon. The second molar has two anterior cusps on the same transverse line, and a posterior 
broad flat talon; the last lower molar is the smallest of all the teeth. 
