330 ANATOMY OF VERTEBRATES. 



of each of these premolars is traversed by a longitudinal ridge. 

 The fourth premolar above is the carnassial tooth, and has 

 its long blade divided by two notches into three lobes, the 

 first a small thick cone, the second a long and compressed cone, 

 the third a horizontal, sinuous, trenchant plate ; a strong tri- 

 cdral tubercle, t, is developed from the inner side of the base of 

 the anterior part of the crown. The single true molar of the 

 upper jaw is a tubercular tooth of small size. The first premolar 

 of the lower jaw fits into the interspace between the first and 

 second premolars above, and answers, therefore, to the second 

 lower premolar in the Viverridce. The second is the largest of the 

 lower premolars ; its crown forms chiefly a strong rounded cone, 

 girt by a basal ridge, and might serve as the model of a hammer 

 for breaking stones. The last lower tooth is the sectorial,' as in 

 Felis. The deciduous teeth consist of 



.3.3 1.1 3.3 



Z 3^ ;c n ;m 3^ = 28 - 



The permanent dentition of the Hy&na assumes those charac- 

 teristics which adapt it for the peculiar food and habits of the 

 adult : of these the chief is the great size and strength of the 

 molars as compared with the canines, and more especially the thick 

 and strong conical crowns of the second and third premolars in 

 both jaws, the base of the cone being belted by a strong ridge 

 which defends the subjacent gum. This form of tooth is especially 

 adapted for gnawing and breaking bones, and the wdiole cranium 

 has its shape modified by the enormous development of the muscles 

 which work the jaws and teeth in this operation. Adapted to 

 obtain its food from the coarser parts of animals which are left by 

 the nobler beasts of prey, the hyaena chiefly seeks the dead carcass, 

 and bears the same relation to the lion which the vulture does to 

 the eagle. 



The family Viverridce, which comprehends the Civets, Genets, 

 Ichneumons, Musangs, Surikates, and Mangues, is characterised, 

 with few exceptions, by the following formula :- 



.3.3 1.1 4.4 2.2 

 Z 373 ;C L1^474 ;7n 272 =4a 



It differs from that of the genus Canis by the absence of a tuber- 

 cular tooth, m 3, on each side of the lower jaw ; but, in thus 

 making a nearer step to the feline dentition, the Viverridce, on the 

 other hand, recede from it by the less trenchant and more tuber- 

 cular character of the sectorial teeth. 



The canines are more feeble, and their crowns are almost 



