CARNIVORA 



383 



M. latidens) ; and by others of the size of a leopard (M. pal- 

 midens and M. megantercon). This form is first found in the 

 miocene of Auvergne and of Eppelsheim ; next in the plio- 

 cene of the Val d'Arno ; and finally in cave breccia in 

 Devonshire. 



The penultimate tooth in the upper jaw and the last 

 tooth in the lower jaw were denominated by Cuvier "dents 

 carnassieres." The carnassial 

 or sectorial is a very charac- 

 teristic tooth in the carnivo- 

 rous order, but undergoes many 

 modifications, and preserves 



its typical form, as repre- Working surface of the upper sectorial 



sented in figures 130 and 131, t00th ' Hy£ena - Nat - size - 



only in the most strictly flesh-feeding species. In it may be 

 distinguished the part called the "blade" (fig. 130, b, b), and 

 the part called the " tubercule" (fig. 130, t). The lower sec- 

 torial in the genus Felis consists exclu- 

 sively of the blade (fig. 131), which is 

 pretty equally divided into two lobes. 

 The blade of the upper sectorial always 

 plays upon the outside, and a little in 

 advance of the lower sectorial. j 



The upper sectorial succeeds and §M 

 displaces a deciduous tubercular molar 

 in all Carnivora, and is, therefore, essen- 

 tially a premolar tooth ; the lower sec- 

 torial comes up behind the deciduous ^. 



. . F] s- mi- 



series and has no immediate predeces- g^e v ; ew of i ower sec torial 



sor ; it is, therefore, a true molar, and tooth > Lion - Nat. size, 

 the first of that class. The sectorial teeth present gradational 

 varieties of form in the carnivorous series, from Machairodus, 

 in which the crown consists exclusively of the " blade" in both 

 jaws, to Ursus (fig. 132, m i),in which it is totally tubercular ; 



