XI ERYMANTHINE BOAR 279 
Dicotylidae, contains but one genus, Dicotyles, with at most two 
species. The name of the animal is connected with the dorsal 
gland; the animal thus appeared to possess two navels. The 
Pecearies, exclusively confined to the New World, differ from 
the Old-World Pigs in one or more important characters. They 
have only three toes on the hind-feet, and the stomach is com- 
plicated. Though the Peccaries have but small tusks they hunt 
in packs and are very dangerous animals to meet with. They 
owe, too, their safety from many foes to their sociable habits. 
Being nocturnal animals they are lable to the attacks of the 
Jaguar, which will speedily overpower and devour a Peccary that 
has strayed from its herd. 
Fossil Swine.—The existing genera of the Pig tribe are also 
known in a fossil condition. Sws itself goes back as far as the 
Upper Miocene. Sus erymanthius, the Erymanthine Boar, is 
known from beds of that age in Greece, England, and Germany. 
This genus is not known to have had a wider distribution in the 
past than it has in the present. icotyles occurs in the Pleisto- 
cene of both North and South America, the regions which it 
inhabits at the present day. The genus Listriodon, also Miocene, 
is remarkable for having lophodont instead of bunodont teeth, 
that is so far as concerns the molars, which resemble those of 
the Tapir. It was European and Indian in range. A number 
of genera, more remote from the existing Pigs than those which 
have just been dealt with, are placed together in a special 
sub-family, Achaenodontinae. The type genus, Achaenodon, had 
a somewhat short skull for a Pig; and it is in general aspect 
and in the characters of the canine teeth highly suggestive of 
that of a Carnivore. The bunodont molars, however, are Suine, 
as is the form of the lower jaw with a rounded angle. This is 
an Kocene animal found in Wyoming. 
Elotherium* occurs chiefly in the Miocene of both North 
America and Europe; but #. wintense is Eocene. The orbits 
are completely encircled by bone in the more modern forms; this 
is not the case in the last-described genus, with which Z. wintense 
agrees. The skull is also longer and more Pig-like. The zygo- 
matic arch is powerful, with sometimes a large descending process, 
such as is found in Diprotodon, more faintly in Kangaroos, and in 
Sloths and certain extinct Edentates. The lower jaw has a pair 
1 Marsh, Amer. Journ. Sci. xlvii. 1894, p. 407. 
