DICOTYLID& 291 



inflicting severe wounds with its sharp tusks. A hunter who en- 

 counters a herd of them in a forest has often to climb a tree as 

 his only chance of safety. Both species are omnivorous, living on 

 roots, fallen fruits, worms, and carrion ; and when they approach 

 the neighbourhood of villages and cultivated lands they often 

 inflict great devastation upon the crops of the inhabitants. 



Remains of the two existing species of Peccary, as well as of one 

 much larger extinct form, are found in the cavern-deposits of Brazil ; 

 while large Peccaries also occur in the Pleistocene of the United 

 States, which, although they have been referred to a distinct genus, 

 Platygonus, on account of their relatively smaller incisors and some- 

 what simpler premolars, may well be included in Dicotyles. 



Allied Extinct Genera. In the Tertiary deposits of both 

 the Old and New World occur remains of Pig -like animals 

 which, so far as we can judge, appear to connect the Peccaries 

 so closely with the true Pigs as to render the Dicotylidw 

 really inseparable from the Suidce. Of these the American 

 genus Chcenohyus has the lower canine with a triangular cross 

 section and received into a notch in the upper jaw, as in the Pec- 

 caries, but the fourth upper premolar is simpler than the molars, as 

 in the under-mentioned genus Hyotherium. The typical forms have 

 only three premolars, but in others, which it has been proposed to 

 separate generically as Bothriolabis, there are four of these teeth. 

 Hyotherium,, of the Pliocene 

 and Miocene of the Old 

 World, is a generalised 

 form allied both to Sus and 

 Dicotyles as well as to certain 

 extinct genera. The upper 

 molars (Fig. 110) are char- 

 acterised by their square 



Crowns the last having no Fl - HO. The three left upper molars of Hyotheriwn 

 T .. ' . T . T T T perimense. from the Pliocene of India. 



distinct third lobe, and com- 

 ing into use before the first is much worn, while the last premolar is 

 simpler than the true molars. The canines, which have an oval section 

 and are scarcely larger than the incisors, are not received into a 

 notch in the upper jaw. In the Pliocene of India there occurs an 

 apparently allied genus known as Hippohyus, in which the crowns 

 of the molars are much taller, and have lateral infoldings of the 

 enamel, producing a very complex pattern on the worn crowns. 

 The European Miocene genus Listriodon, with the dental formula 

 i | } c | 5 p 3^ m 3 s differs from all the preceding in having the 

 anterior and posterior pairs of tubercles of the molars united into 

 ridges running across their crowns, so that these teeth resemble the 

 lower molars of the Tapir. The genus is also found in the Lower 

 Pliocene of India. 



