DICOTYLID^E 289 



transition came about. The tubercles which cluster over the surface 

 of the crown of the molars of the common Pig are elongated and 

 drawn out into columns in the "Wart-Hog, as the low transverse 

 ridges of the Mastodon's tooth become the leaf-like plates of the 

 Elephant's. 



Two species of this genus are commonly but rather doubtfully 

 distinguished : — /'. africanus, ^Elian's Wart-Hog, widely distributed 

 over the continent; and /'. cetkiopicus, Pallas's Wait-Hog, confined 

 to South-Eastern Africa. In specimens attributed to the latter 

 species the dentition reaches its most complete reduction, as in 

 adult animals the upper incisors are absent and the lower ones worn 

 down to the roots. 



Ft I ill ill/ DlCOTYLID.E. 



Snout as in Swidce. Dentition: i §, c ~, /> J-, m § ; total 38. 

 Incisors rooted ; upper canines directed downwards, with sharp 

 cutting hinder edges. Toes, four on the fore feet and three on the 

 hind feet (the fifth wanting). Stomach complex. A caecum. 

 Confined to the New World. 



Dicotyles. 1 — The teeth of the Peccaries (Dicotylcs) differ from those 

 of the true Pigs (Sus) numerically in wanting the upper outer 

 incisor and the anterior premolar on either side of each jaw, and also 

 in the circumstance that the last premolar is nearly as complex as 

 the molars. The upper canines have their points directed down- 

 wards, not outwards or upwards as in the Boars, and are very 

 sharp, with cutting hinder edges, and completely covered with 

 enamel until worn. The lower canines are large, directed up- 

 wards and outwards, and slightly curved backwards. The pre- 

 molar and molar teeth form a continuous series, gradually increasing 

 in size from the first to the last. The true molars have square 

 quadricuspidate crowns. The stomach is much more complex than 

 in the true Pigs, almost approaching that of the ruminants. In the 

 feet the two middle (third and fourth) metapodial bones, which are 

 completely separate in the Pigs, are united at their upper ends, as 

 in the ruminants. On the fore foot the two (second and fifth) outer 

 toes are equally developed as in Pigs, but on the hind foot, although 

 the inner (or second) is present, the outer (or fifth) toe is entirely 

 wanting, giving an unsymmetrical appearance of the member, very 

 unusual in Artiodactyles. Vertebrae: C 7, D 14, L 5, S 4, C 7. 

 As in the Pigs, the snout is truncated, and tlie nostrils are situated 

 in its flat, expanded, disc-like termination. The ears are rather 

 small, ovate, and erect ; and there is no external appearance of a 

 tail. The surface of the body is well covered w T ith thick bristly 

 hair, and rather behind the middle of the back is a large and 



1 Cuvier, Regne Animal, vol. i. p. 237 (1817). 

 19 



