p including the Indian _G. bennetti_
and the Arabian _G. arabica_, in which the horns have a somewhat
S-shaped curvature in profile. In the group represented by the African
_G. granti_, _G. thomsoni_, _G. mohr_, &c., the white of the buttocks
often sends a prolongation on to the flanks, the horns are long and the
size is large. Lastly, the Central Asian _G. gutturosa_, _G.
subgutturosa_ and _G. picticaudata_ form a group in which the females
are hornless and the face-markings inconspicuous or wanting.

The South African springbuck (_Antidorcas euchore_) is nearly related to
the gazelles, from which it is distinguished by the presence on the
middle line of the loins of an evertible pouch, lined with long white
hairs capable of erection. It has also one premolar tooth less in the
lower jaw. Formerly these beautiful antelopes existed in countless
numbers on the plains of South Africa, and were in the habit of
migrating in droves which completely filled entire valleys. Now they are
comparatively rare.

The dibatag or Clarke's gazelle (_Ammodorcas clarkei_), of Somaliland,
forms a kind of connecting link between the true gazelles and the
gerenuk, this being especially shown in the skull. The face has the
ordinary gazelle-markings; but the rather short horns--which are wanting
in the female--have a peculiar upward and forward curvature, unlike that
obtaining in the gazelles and somewhat resembling that of the reedbuck.
The neck is longer and more slender than in ordinary gazelles, and the
tail is likewise relatively long. Although local, these animals are
fairly common in the interior of Somaliland, where they are known by the
name of dibatag. In running, the head and neck are thrown backwards,
while the tail is turned forwards over the back.

The East African gerenuk (q.v.), or Waller's gazelle (_Lithocranius
walleri_), of which two races have been named, is a very remarkable
ruminant, distinguished not only by its exceedingly elongated neck and
limbs, but also by the peculiar hooked form of the very massive horns of
the bucks, the dense structure and straight profile of the skull, and
the extreme slenderness of the lower jaw.

A still more aberrant gazelle is a small North-East African species
known as the beira (_Dorcatragus melanotis_), with very short horns,
large hoofs and a general appearance recalling that of some of the
members of the subfamily _Neotraginae_, although in other respects
gazelle-like. The blackbuck