ON THE TEETH OF MAMMALIA. 119 



of the tooth : it is large, strong, and powerful ; of a compressed shape ; 

 and divided into two or more trenchant conical points, often having, also, 

 a small inner tubercle. The action of the carnassiere of the upper jaw, 

 with respect to its correspondent tooth in the lower jaw, is scissor-like. 

 Posterior to the carnassiere succeed the tuberculous molars, never being 

 more than three in number, except in the marsupials, in which they are 

 four. These are less numerous and smaller in the Cats and Mustelae than 

 in the Dogs : the Cats, in fact, have a small tuberculous molar only, in the 

 upper jaw, but none in the lower. In the Mustelae, or Weasel tribe, there 

 is a very small tuberculous molar below, and a larger one above. In the 

 Dog there are two tuberculous molars above, and two below : the first 

 tuberculous molar above, is large and strong ; its greatest measurement 

 is transverse. The sketch of the skull of the Dog (fig. 121) shews the 

 position of the zygomatic arch, , with respect to the carnassiere, 6. 



Skull of Dog. 



In the Bears, the least carnivorous of the order, the carnassiere is 

 scarcely to be so called : and it is followed, in each jaw, by three large 

 tuberculous grinders, adapted for bruising vegetable substances. 



Various formulae have been proposed, by which to give, as succinctly 

 as possible, the dental system of animals : the following is a specimen 

 of that most in use ; and it refers to the Dog : Incisors, f ; canines, 

 |Er ; molars, JlJ ; = 42. 



In this formula the character of the molars is not expressed a ma- 

 terial objection ; otherwise it is simple and intelligible. It indicates 

 that there are three incisors on each side above, and three below ; one 

 canine on each side, above and below ; and six molars on each side 

 above, and seven on each side below. But, as the character of the 

 molars is not given, the formula may be modified, with advantage, as fol- 

 lows : Incisors, -3 ; canines, |Ei ; molars, false, 1 ; carnivorous, |E} ; 

 tuberculous, 3 5 = 42. 



The dentition of the genus Felis will stand thus : Incisors, |E ; 

 canines, |E} ; molars, false, 5=5 ; carnivorous, |-Er ; tuberculous, S ; = 30. 



The dentition of Man consists of Incisors, l~ 2 ; canines, \2\ ; molars, 

 false, or bicuspid, ^ ; true, 3 ; = 32. 



