278 UNGULATA 



Tragulina, and Pecora into which the existing members of the 

 suborder have become divided, that in a general classification 

 embracing both living and extinct forms these divisions cannot be 

 maintained. In the present work, however, it will be convenient 

 to retain them, mention being made of some of the chief annectant 

 forms in separate sections. 



SUINA. 



The existing members of this group are characterised by their 

 bunodont molars, and the absence of a complete fusion of the third 

 and fourth metapodials to form a "cannon-bone." The full 

 Eutherian dentition is very frequently present. 



Remains of very generalised swine -like animals have been 

 abundantly found in Tertiary formations both in America and 

 Europe. In the former continent they never (so far as present 

 evidence indicates) underwent any great diversity of modification, 

 but gradually dwindled away and almost died out, being only re- 

 presented in the actual fauna by the two closely allied species of 

 Peccary, among the smallest and most insignificant members of the 

 group, which have existed almost unchanged since the Miocene age 

 at least, if the evidence of teeth alone can be trusted. In the Old 

 World, on the other hand, the swine have played a more important 

 part in recent times, having become widely distributed, and throwing 

 off some curiously specialised forms. At the present time, though 

 not very numerous in species, they range through the greater part 

 of the Old World, except within or near the Arctic Circle, although, 

 in common with all the other members of the great Ungulate order, 

 they were completely absent from the whole of the Australian region, 

 until introduced by man in very recent times. 



The existing swine-like animals may be divided naturally into 

 three families: I. Hippopotamidce ; II. Suidce, or true Pigs; III. 

 Dicotylidce, or Peccaries. 1 



Family HIPPOPOTAMIDCE. 



Muzzle very broad and rounded. Feet short and broad, having 

 four subequal toes, with short rounded hoofs, all reaching 

 the ground in walking. Incisors not rooted, but continuously 

 growing ; those of the upper jaw curved and directed downwards ; 

 those of the lower straight and procumbent. Canines very large, 

 curved, continuously growing ; those of the upper jaw directed 

 downwards. Stomach complex. No caecum. 



Hippopotamus. 2 This genus may be taken to include all the 

 known members of the family ; it appears to have been always 



1 In the table on p. 89 the Peccaries are included in the Suidce. 

 - Linn. Syst. Nat. 12th ed. vol. i. p. 101 (1766). 



