Fig. 163.—Beatrix Antelope. Oryx beatrix. × 1⁄16. (From Nature.)

The genus Oryx (chiefly African, but also Arabian and Syrian) also contains a number of species, which are fairly familiar through the fact that several of them are always on view in the Zoological Society's Gardens. The genus differs from Hippotragus in that the horns, present in both sexes, are placed behind the orbits, and slant backwards in a line with the face. They are annulated. The Leucoryx (O. leucoryx) is of a pale colour, but

this is not so marked as in O. beatrix, which is largely white with, however, brown legs. The Gemsbok is a handsome creature with greyish tawny colour, much darker on the legs, and with a Gazelle-like, dark, side stripe. It has received its vernacular name on account of its supposed likeness to the Chamois ("Gemse"), just as the Rehbok was so-called from its supposed likeness to the Roe Deer, and the Eland to the Elk. The Beisa (O. beisa) is of a similar tawny colour to the last, and also with darker stripes.

The Addax (Addax) of North Africa, Arabia and Syria, has but one species (A. nasomaculatus). The horns are spirally twisted.

Fig. 164.—Speke's Antelope. Tragelaphus spekii (♀). × 1⁄16.

The Tragelaphine section includes the Kudus, Elands, Nilgais, and Harnessed Antelopes. They are all long-horned (when the horns are present in both sexes), the horns being twisted; the nose is naked with a slight median groove, and all are Ethiopian or Oriental in range.

The genus Tragelaphus includes the Harnessed Antelopes, so called on account of the direction of the stripes suggesting harness. The females are hornless, and the colours of the two sexes are different. The hoofs are long and the toes rather unusually separable, which state of affairs is in accord with the

swampy country affected by many. T. gratus and T. spekei are larger forms; the Boschbok, T. sylvaticus, is smaller.

The Kudus, genus Strepsiceros, have more markedly twisted horns, which are absent in the female. The body is vertically striped with white. The largest species is S. kudu; a smaller form, S. imberbis, is from Somaliland.