arly circular in section and
almost smooth; usually they curve outward, then upward and often inward
at the tip; the premaxillaries are long and generally reach to the
nasals, and the anterior dorsal vertebrae are without sharply elongated
spines, so that the line of the back is nearly straight. These, the true
oxen, as they are sometimes termed, now exist only in domesticated
breeds of cattle.

In the gaur oxen (_Bibos_) the horns are situated as in _Bos_,
high up on the vertex, but are more elliptical in section; the
premaxillaries are short; the dorsal vertebrae, from the third to the
eleventh, bear elongated spines which produce a hump reaching nearly to
the middle of the back; the tail is shorter, and the hair is short all
over the body. The three species--gaur, gayal and banteng--inhabit
Indo-Malayan countries, and all of them are dark brown with white
stockings.

The buffaloes (_Bubalus_) are large and clumsy animals with horns
more or less compressed or flattened at their bases, set low down on the
vertex, which does not show the high transverse ridge of true oxen and
gaurs. In old bulls of the African species the horns meet at their base
and completely cover the forehead. In the arni of India they are
enormously long. The dorsal spines are not much elongated, and there is
no distinct hump; the premaxillae are long enough to reach the
nasals. Hair is scanty all over the body, and old animals are almost
wholly bare. The small and interesting anoa of Celebes, and the tamarao
of Mindoro, are nearly related in all important respects to the Indian
buffalo, and the carabao, used for draught and burden in the
Philippines, belongs to a long domesticated race of the same animal.

Finally, in the genus _Bison_ the horns are below the vertex as in
buffaloes, but are set far apart at the base, which is cylindrical; they
are short and their curve is forward, upward and inward; the anterior
dorsal and the last cervical vertebrae have long spines which bear a
distinct hump on the shoulders; the premaxillae are short and never
reach the nasals; there are fourteen, or occasionally fifteen, pairs of
ribs, all other oxen having but thirteen, and there is a heavy mane
about the neck and shoulders. The yak of central Asia is very bison-like
in some respects, but in others departs in the direction of oxen.

So at last, group by group, we have gone through the ungulates, and the
bisons alone are left, and as the American animal ha