At present, the Proboscidea are restricted to the warmer parts of Asia and Africa, where five species, four of them African, are recognized. This is a very great reduction in the number of species and in the area inhabited during the Pleistocene epoch, when they ranged through every continent, except Australia, and were adapted to every climate from the tropics to the shores of the Arctic Sea. Four distinct species of proboscideans existed in Pleistocene North America, three elephants and a †mastodon, though not all in the same areas, nor probably all at the same time, their ranges both in time and space overlapping to a greater or less degree, but not exactly coinciding in either respect. [Illustration: FIG. 225.—Vertical section through the manus of the Indian Elephant. _U_, lower end of ulna. _L_, lunar. _M_, magnum. _III_, third metacarpal. _1_, _2_, _3_, phalanges. _E_, pad of elastic tissue. (After M. Weber.)] The first species was an immigrant, the northern †Mammoth (_Elephas †primigenius_), which extended over the greater part of the northern hemisphere, both in the Old World and in the New. This is the species of which complete carcasses with hide and hair have been found in the frozen gravels of northern Siberia, its structure and appearance being thus almost as well known as those of any modern elephant. That the †Mammoth was perfectly adapted to life in a climate of severe cold is shown not only by the contents of the stomach, which are comminuted fragments of present-day Siberian vegetation, but also by the dense coat of woolly hair, covered by long, coarse outer hair, which afforded full protection against the cold. The tusks, with considerable variation of form, had a tendency to spiral curvature, curving first downward and outward, then upward and inward; the grinding teeth were characterized by their relative breadth and the numerous thin enamel-ridges which traversed them. The number of these ridges was very variable in different individuals, but may be expressed for the six successive teeth as follows: 3-4, 6-9, 9-12, 9-15, 14-16, 18-27. The skeleton was more like that of the Indian Elephant than of the other species, though with a number of small differences in the skull. In size, the †Mammoth was comparatively small, standing about nine feet six inches at the shoulders. In North America its range was from Alaska southeastward across the continent to New England.