216 
GEOGRAPHICAL ZOOLOGY. 
[PAKT IV. 
Oregon, and Arkansas. Elotherium is said to be allied to the 
peccary and hippopotamus. Hyopotamus , from the Miocene of 
Dakota, is allied to Anthracotheriim , and forms with it (accord- 
ing to Dr. Leidy) a distinct family of ancestral swine. 
It thus appears, that the swine were almost equally well re- 
presented in North America and Europe, during Miocene and 
Pliocene times, but by entirely distinct forms ; and it is a re- 
markable fact that these hardy omnivorous animals, should, like 
the horses, have entirely died out in North America, except a 
few peccaries which have preserved themselves in the sub-tropical 
parts and in the southern continent, to which they are compara- 
tively recent emigrants. We can hardly have a more convincing 
proof of the vast physical changes that have occurred in the 
North American continent during the Pliocene and Post-pliocene 
epochs, than the complete extinction of these, along with so 
many other remarkable types of Mammalia. 
According to M. Gaudry, the ancestors of all the swine, with 
the hippopotami and extinct Antliracotlierium, Merycopotmwm, 
and many allied forms, — are the Ryracotherium and Pliolophus, 
both found only in the London clay belonging to the Lower 
Eocene formation. 
Family 48, — CAMELIDiE. (2 Genera, 6 Species). 
General Distribution. 
Neotropical 
Sob-regions. 
Ne ARCTIC 
Sub-regions. 
PALtKARCTIC 
Sub- regions. 
Ethiopian 
Sub-regions. 
Oriental 
Sub-regions. 
Australian 
Sub-regions. 
I 
Living Species. 
2.3 j ■ 
l 
Extinct Species. 
1 
-2.3.4 
3 — 
The Camels are an exceedingly restricted group, the majority 
of the species now existing only in a state of domestication. The 
genus Camelus (2 species), is a highly characteristic desert form 
