Size medium or small; build generally thick and clumsy; naked muzzle large; anteorbital glands opening into a row of pores, which form a long naked line on each side of the muzzle; crown of head tufted, so that the horns are often quite hidden in the hairs; tail short or medium, not heavily tufted; mammæ four; lateral hoofs well developed. Skull with large lachrymal fossæ, but no fissure at the base of the nasals, and no large pits above or beneath the eyes; auditory bullæ divided by a septum; upper molar teeth short and broad; in the larger species with an additional column on the inner side. Horns two, generally present in both sexes, short and spike-like, placed very far back on the head, on the ends of the posteriorly extended frontals; directed straight backwards nearly in the line of the profile, not twisted or curved; their bases often roughened or angulated. _Distribution._ Africa south of the Sahara. This genus, although large, and with species ranging in size from that of a small donkey down to that of a hare, is yet a very uniform and natural one, and shows remarkably little diversity among its members in essential characters. To sportsmen in general the majority of the species are little known, partly owing to their being too small to afford any sport and with but poor horns for trophies, but mainly owing to their inhabiting thick bush, so that they are hardly ever seen. One species, however, the common S. African Duiker, the popular name of which we have extended to all the members of the genus, is well known to every sportsman who has visited that country, both on account of its extreme abundance in most localities, and of its inhabiting more open districts than its congeners, the Bush-Duikers. It has allies in Abyssinia and Senegal, and the three have together been separated by some authors as a distinct genus, bat this separation we are not at present prepared to endorse. Considering, then, all the Duikers as forming but one genus, we may distinguish them according to the following synopsis, although, as three or four of the species are known from very insufficient materials, we may expect that the characters will require some modification hereafter. From the localities appended it will be seen that the large majority of the species are West African in habitat, the great tropical forest which covers so much of that part of Africa being apparently especially suited to their bush-loving habits. A. Horns, when present, pointed directly backwards, in a line with, or below the line of, the nasal profile; generally present in the female. Ears moderate or short, rounded, their length much less than the distance from the eye to the nose. General colour fulvous, red, grey, or black, generally marked or striped. (BUSH-DUIKERS.) _a._ Size large: hind foot (without hoof) more than 11 in.; basal length of skull more than 9·5.·´