The type genus _Hippotragus_ has its horns placed above the orbits; they are not twisted, but curved backwards. There are three species in the genus. Of these the best known is _H. niger_, the beautiful Sable Antelope. Its general colour is a rich, dark, glossy brown with white stripes on the face, and with a white belly. The other species are the Roan Antelope, _H. equinus_, and the Blaaubok, _H. leucophaeus_, of which the last specimen was probably killed in 1799.[213] [Illustration] FIG. 163.--Beatrix Antelope. _Oryx beatrix._ x 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 {315} 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. [Illustration] FIG. 164.--Speke's Antelope. _Tragelaphus spekii_ ([female]). x 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 {316} 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. [Illustration] FIG. 165.--Eland. _Orias canna._ x 1/25.