CANID& 547 



or heel, occupying about one-third of the whole length of the tooth. 

 The second molar is less than half the length of the first, with a 

 pair of cusps placed side by side anteriorly, and a less distinct 

 posterior pair. The third is an extremely small and simple tooth, 

 with a subcircular tuberculated crown and single root. 



The cranium (Fig. 249) is more or less elongated, the facial 

 portion tapering forwards and compressed. The jaws are elongated, 

 and the zygomata moderately strong. The postorbital processes of 

 the frontal short, leaving the orbit widely open posteriorly. Verte- 

 brae: C 7, D 13, L 7, S 3, C 17-22. Clavicles present, but very 

 rudimentary. Limbs of moderate proportions, digitigrade. Feet 

 short ; five toes on the fore foot, the pollex much shorter than the 

 others, and not reaching to the ground. Four toes on the hind 

 foot, the hallux being represented by a rudiment of the metatarsal. 1 

 All the toes are provided with exserted, non- re tractile, slightly 

 curved, and blunt claws, which, being exposed, become worn at the 

 tips. Tail moderate, or rather long, generally somewhat bushy. 

 The pupil of the eye, when contracted, is in some species round, in 

 others elliptical and vertical. 



This extensive genus may be considered as truly cosmopolitan. 

 One or more species occur in every part of the American continent 

 from Greenland to Patagonia and the Falkland Isles; and similarly, 

 in the Old World, Europe, Africa, and Asia, with most of the large 

 islands adjacent, and even Australia, have their wild Dogs, though 

 in the last case they may belong to a feral race, introduced origin- 

 ally by man. They are generally sociable animals, hunting their 

 prey in packs. Many species burrow in the ground ; none habitu- 

 ally climb trees. Though mostly carnivorous, feeding chiefly on 

 animals they have chased and killed themselves, many, especially 

 among the smaller species, eat garbage, carrion, insects, and also 

 fruit, berries, and other vegetable substances. The species are 

 very numerous, and, as in most other large genera, very ill-defined, 

 few zoologists agreeing as to which of the many slightly different 

 modifications should be considered as local varieties and which true 

 species. Perhaps the best cranial character by which the different 

 members of the genus can be distinguished is that pointed out by 

 Burmeister, viz. that in the animals generally called Dogs, Wolves, 

 and Jackals the postorbital process of the frontal bone is regularly 

 smooth and convex above, with its extremity bent downwards, 

 whereas in Foxes this process is holloAved above, with its outer 

 margin (particularly of the anterior border) somewhat raised. This 

 modification coincides in the main with that upon which Professor 



1 In Domestic Dogs a hallux is frequently developed, though often in a rudi- 

 mentary condition, the phalanges and claw being suspended loosely in the skin, 

 without direct connection with the other bones of the foot ; it is called by dog- 

 fanciers the "dew claw." 



