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 Ar otic 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. Hippopotamide ; IL. Suide, or true Pigs; III. 
Dicotylide, or Peccaries.1 
Family HippopoTaMIp&. 
Muzzle very broad and rounded. Feet short and broad, havi ing 
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 lar ge, 
curved, continuously growing ; those of the upper jaw directed 
downwards. Stomach complex. No cxeum. 
Hippopotamus.2—This genus may be taken to include all the 
known members of the family; it appears to have been always 
1 Tn the table on p. 89 the Peccaries are included in the Suide. 
? Linn. Syst. Net. 12th ed. vol. i. p. 101 (1766). 
