m a ridge above the eyes at an obtuse angle to
the plane of the lower part of the face, and then sweep backwards in a
bold curve; while there are tufts of long white hairs near the eyes. The
sable antelope is a southern species in which both sexes are black or
blackish when adult, while the lighter-coloured and larger roan antelope
has a much wider distribution. The South African blauwbok (_H.
leucophaeus_) is extinct. In the addax (_Addax nasomaculatus_), which is
a distinct species common to North Africa and Syria, the ringed horns
form an open spiral ascending in the plane of the face, and there is
long, shaggy, dark hair on the fore-quarters in winter. The various
species of oryx differ from _Hippotragus_ by the absence of the white
eye-tufts, and by the horns sloping backwards in the plane of the face.
In the South African gemsbuck (_Oryx gazella_), fig. 3, the East African
beisa or true oryx (_O. beisa_), and the white Arabian (_O. beatrix_)
the horns are straight, but in the North African white oryx or algazel
(_O. leucoryx_ or _O. algazal_) they are scimitar-shaped, the colour of
this species being white and pale chestnut (see ADDAX, ORYX, and SABLE
ANTELOPE).

The third subfamily is the _Antilopinae_, the members of which have a
much wider geographical range than either of the foregoing groups. The
subfamily is characterized by the narrow crowns of the molars, which are
similar to those of sheep, and the hairy muzzle. Generally there are
face-glands below the eyes; and the tail is moderate or short. Pits are
present in the forehead of the skull, and the horns are ringed for part
of their length, with a compressed base, their form being often lyrate,
but sometimes spiral. Lateral hoofs are generally present.

[Illustration: FIG. 3.--Gemsbuck, or Cape Oryx (_Oryx gazella_).]

Gazelles (_Gazella_), which form by far the largest genus of the
subfamily, are inhabitants of open and frequently more or less desert
districts. They are mostly of a sandy colour, with dark and light
markings on the face, and often a dark band on the flanks. The horns are
more or less lyrate, and generally developed in both sexes; there are
frequently brushes of hair on the knees. Gazelles may be divided into
groups. The one to which the North African _G. dorcas_ belongs is
characterized by the presence of lyrate or sub-lyrate horns in both
sexes, and by the white of the buttocks not extending on to the
haunches. Nearly allied is the grou