Size medium; form much more delicate and slender than in any of the species hitherto considered. Ears long, longer than the distance from the anterior canthus to the tip of the nose, their tip narrow and pointed. General colour of body pale greyish brown, sometimes with a yellowish tinge, but very variable in tone; more or less grizzled, owing to the hairs being annulated with yellowish and brown. Face rufous or yellowish, with a deep brown longitudinal patch on the nasal region, rarely extending upwards to the bases of the horns. Throat and belly like back. Chin, inner sides of fore arms and of thighs, and underside of tail whitish or pure white. Front of fore legs with a brownish line running down them to the hoofs. Metapodials brown. Tail black above and white below, but the base above is commonly coloured like the back. Horns normally present only in male. These (see fig. 22, p. 207) are set up at a considerable angle to the line of the nasal profile, slender, tapering, attaining to about 5 inches in length, their bases roughened but not markedly thickened, their greatest basal diameter going about 6 or 7 times in their length. Skull long and narrow. Anteorbital fossæ of medium depth, their border above generally rounded, not sharply ridged. Muzzle long, the distance from the anterior edge of the orbit to the gnathion much exceeding the greatest zygomatic breadth. Mesial notch of palate extending some way in front of the lateral ones. Dimensions:--♂. Height at withers 23 inches, ear 4·3, hind foot 10·3. Skull: basal length 7·2 inches, greatest breadth 3·3, anterior rim of orbit to muzzle 4·4. _Hab._ South Africa, extending on the west northwards to Angola and on the east up to British East Africa and Somaliland. The little Antelope called at the Cape the “Duiker” or “Diver,” not from its going into the water, but from its “diving” so quickly into the bushes when alarmed, has been more or less perfectly known to the naturalists of Europe for the past 200 years. Described by Grimm in 1686 as the _Capra sylvestris africana_ it was dedicated to that naturalist by Linnæus, when he adopted the binomial system, as the _Capra_ or _Moschus grimmia_. This term, slightly modified in accordance with modern usage, we propose to adopt as its specific name. Other early names bestowed upon it were _Antilope nictitans_ by Thunberg, of whose travels to the Cape we have already spoken, and _Antilope mergens_ by Blainville, while various appellations, which are specified in our synonymy, were given to this species and its varieties by Andrew Smith, Hamilton Smith, Gray, and Fitzinger. [Illustration: Fig. 22. Skull of _Cephalophus grimmi_. (P.Z.S. 1871, p. 591.)]