xi ERYMANTHINE BOAR 379 



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 

 Peccaries, 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 liable 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. Sus 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. Dicotyles 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 Eocene animal found in Wyoming. 



Elotherium 1 occurs chiefly in the Miocene of both North 

 America and Europe ; but E. uintense 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 E. uintense 

 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, Aimr. Journ. Set. xlvii. 1894, p. 407. 



