BABIROUSSA. 



547 



depression on the first and second true molars is deeper in the 

 lower than in the upper jaw; its borders of enamel are very 

 sinuous ; in the second true molar each anterior lobe is penetrated 

 by a secondary fold at its posterior margin, and the posterior 

 division is divided into three lobes, the enamel coats of which 

 form three islands arranged in a triangle when the surface is 

 worn down to a certain extent : the last molar is divided by 

 two transverse depressions into three principal lobes, the last 

 being the longest in the common Hog, and the shortest in the 

 Masked Hog; the two anterior divisions are each subdivided by 

 the longitudinal furrow into two tubercles, and these are broken 

 by many secondary depressions into smaller tubercles. The inferior 

 canines of the Wild Boar are longer, and curve upwards, out- 

 wards, and backwards, in a more normal direction than those 

 above : they are three-sided ; the broadest convex side is directed 

 obliquely inwards and forwards ; the outer and posterior sides are 

 nearly flat ; the latter surface has no enamel, and the tusk wears 

 obliquely from behind, upwards and forwards to a point, with two 

 sharp enamel edges. Both upper and lower canines have the 

 characters of true tusks in the projection of their crown beyond 

 the lips, and their insertion by a long undivided and undiminished 

 base, widely excavated for a persistent matrix which ensures the 

 uninterrupted growth of these formidable weapons. Each tusk in 

 a lower jaw of one foot in length, from a German Wild Boar, 

 measures eight inches along its curve : but tusks of twelve 

 inches in length have been obtained from the Wild Boars of 

 Assam. 



The smaller species of Asiatic Hog, called Babiroussa, has 

 obtained from the extraordinary development and direction of its 

 tusks the name of ' horned Hog' (PL 140, fig. 3) ; and both molar 

 and incisor teeth offer some varieties from those of the ordinary 

 species of Sus. The incisors are reduced to four in number in 

 the upper jaw by the early loss of the two small outer ones ; the 

 first and second, on each side, which remain, correspond in form 

 with those of the common Hog. The six incisors are retained in 

 the lower jaw. The upper canines are more slender than in the 



N N 2 



