329 



about twice as long as wide, the sides gradually converging 

 posteriorly ; hamulars slender, straight ; incisive foramina about 

 four times as long as wide, the median septum usually wider 

 than the foramen, the posterior margin a little in front of 

 posterior margin of alveolus of canine. Mandible slender, but 

 with no special peculiarities of form. 



Teeth. — In general form and structure the teeth do not differ 

 very widely from those of Canis lupus. The canines are, however, 

 relatively much longer and more slender (fig. 65), the incisors are 

 weaker and narrower, and the premolars show a more decided 

 tendency to develop secondary 

 cusps. Upper incisors slender, 

 not closely crowded, their 

 crowns relatively narrower than 

 in either Canis lupus or Alopex 

 lagopus, the secondary cusps 

 obsolete, early disappearing 

 with wear, the cingulum barely 

 indicated ; lower incisors with 

 crowns less simplified than in 

 the upper teeth, the usual lon- 

 gitudinal groove present on 

 posterior surface, and i^ with 

 well developed outer basal lobe. 

 Upper canine slender, its dia- 

 meter at alveolus about 7 mm., 

 its height when unworn usually 

 about three times as great ; 

 lower canine with diameter 

 contained about 2^ times in 

 height. Premolars with no 

 special peculiarities, their crowns 

 relatively narrower than in 

 Canis lupus, and secondary cusps 

 tending to be more developed, 

 the latter character varying in 

 different geographical forms. pjg gy 



Upper carnassial with inner VtUpes vuipes. Teeth. Nat. size. 



lobe better developed than in 



Canis, and bearing a distinct terete cusp, its position a little 

 more forward and outward than in the dogs, so that it appears 

 to lie in or nearly in the main axis of the tooth. Lower carnassial 

 with posterior heel essentially as broad as main portion of tooth, 

 the cusps essentially as in Canis, but general aspect of tooth more 

 trenchant. Upper molars differing from those of Canis in the 

 I'elatively smaller size of paracone and metacone, these cusps 

 appearing to stand in from border of crown, leaving a noticeable 

 cingulum beyond them ; paraconule obsolete. Second and third 

 lower molars with no marked peculiarities. 



