442 
UNGULATES. 
The Peccaries. 
Family DlCOTYLIDAH. 
The peccaries, which are the American representatives of the swine, differ so 
markedly from the latter that they are regarded as belonging to a separate family, 
of which there is but a single genus. The most important differences between the 
two groups are that the upper tusks of the peccaries have their points directed 
downwards instead of upwards, that their hind-limbs have three instead of four 
toes, while instead of the simple stomach of the Old World swine, the peccaries 
have a complex one approaching that of the Ruminants. 
Peccaries have a total of thirty-eight teeth, that is to say, they have a pair of 
THE COLLARED PECCARY AND YOUNG (j Rat. size). 
incisors in the upper jaw, and a premolar on each side of both jaws less than the 
wild boar. The downwardly-directed upper tusks, which are at first completely 
covered with enamel, are of small size, with sharp cutting-edges behind; while 
those of the lower jaw are directed upwards, outwards, and slightly backwards, 
and are received in notches in the sides of the opposite jaw just in front of the 
upper tusks. The last molar tooth in each jaw lacks the hind lobe characteristic 
of the Old World swine (see fig. on p. 421), and the fourth premolar tooth in the 
upper jaw resembles the first molar in having four tubercles on its crown, instead 
of only three. In addition to the difference in the number of toes in the hind-feet, 
the peccaries are further distinguished by the upper ends of the two larger meta¬ 
carpal and metatarsal bones being united, so that we have here an approach to the 
formation of cannon-bones. In this respect, as well as in the complex structure of 
their stomachs, and the presence of four tubercles on their last upper premolar 
teeth, the peccaries are clearly one step in advance of their allies of the Old World. 
