lustration: Fig. 264--Skeleton of the "Irish Elk" (_Cervus
megaceros_). Post-Pliocene, Britain.]

Amongst the Even-toed Ungulates, the great _Hippopotamus major_
of the Pliocene still continued to exist in Post-Pliocene times
in Western Europe; and the existing Wild Boar (_Sus scrofa_),
the parent of our domestic breeds of Pigs, appeared for the first
time. The Old World possessed extinct representatives of its
existing Camels, and lost types of the living Llamas inhabited
South America. Amongst the Deer, the Post-Pliocene accumulations
have yielded the remains of various living species, such as the
Red Deer (_Cervus elaphus_), the Reindeer (_Cervus tarandus_),
the Moose or Elk (_Alces malchis_), and the Roebuck (_Cervus
capreolus_), together with a number of extinct forms. Among the
latter, the great "Irish Elk" (_Cervus megaceros_) is justly
celebrated both for its size and for the number and excellent
preservation of its discovered remains. This extinct species
(fig. 264) has been found principally in peat-mosses and
Post-Pliocene lake-deposits, and is remarkable for the enormous
size of the spreading antlers, which are widened out towards
their extremities, and attain an expanse of over ten feet from
tip to tip. It is not a genuine Elk, but is intermediate between
the Reindeer and the Fallow-deer. Among the existing Deer of the
Post-Pliocene, the most noticeable is the Reindeer, an essentially
northern type, existing at the present day in Northern Europe,
and also (under the name of the "Caribou") in North America. When
the cold of the Glacial period became established, this boreal
species was enabled to invade Central and Western Europe in great
herds, and its remains are found abundantly in cave-earths and
other Post-Pliocene deposits as far south as the Pyrenees.

[Illustration: Fig. 265.--Skull of the Urns (_Bos primigenius_).
Post-Pliocene and Recent. (After Owen.)]

In addition to the above, the Post-Pliocene deposits of Europe
and North America have yielded the remains of various Sheep and
Oxen. One of the most interesting of the latter is the "Urus" or
Wild Bull (_Bos primigenius_, fig. 265), which, though much larger
than any of the existing fossils, is believed to be specifically
undistinguishable from the domestic Ox (_Bos taurus_), and to be
possibly the ancestor of some of the larger European varieties
of oxen. In the earlier part of its existence the Urus ranged
over Europe and Britain in company