When the late Dr. William Peters made his great expedition to the Portuguese colony of Mozambique from 1842 to 1848 the Zoology of the Eastern Coast of Africa was almost unknown to us. Many, therefore, were the discoveries made by that distinguished traveller and naturalist, and subsequently described in his ‘Naturwissenschaftliche Reise nach Mossambique.’ Amongst them, in the volume devoted to the Mammals of the Expedition, we find a figure and description of the present Antelope, which was met with by Peters on the bush-clad plains of Sena and Shupanga, situated about 17° S. lat., and from 30 to 60 miles from the coast. Peters allows that the present form comes very near the typical _O. scoparia_, but considers that it differs in its longer ears, the smaller size of the naked spot beneath the ear, the white underside of the tail, and the less compressed form of the hoofs. Peters’s specimens are in the Berlin Museum. More recently the British Museum has acquired several skins of an Antelope, which should be the same, to judge from its locality, as Peters’s _O. hastata_, among the splendid collections amassed by Sir H. H. Johnston in Nyasaland with the aid of his naturalist Mr. Alexander Whyte, F.Z.S. These were obtained on the grassy plains between Zomba, where Mr. Whyte is resident, and Lake Shirwa. These materials, however, are not yet sufficient to enable us to pronounce a decided opinion as to whether this Oribi should be really treated of as a species distinct from its brother of the Cape Colony. The two forms certainly come very near one another, and we are rather doubtful whether they can be properly distinguished. _December, 1895._ [Illustration: THE BOOK OF ANTELOPES. PL. XXVI. _Wolf del. Smit lith._ _Hanhart imp._ The Gambian Oribi OUREBIA NIGRICAUDATA _Published by R. H. Porter._] 43. THE GAMBIAN ORIBI. OUREBIA NIGRICAUDATA (BROOKE). [PLATE XXVI.] _Ourebi du Sénégal_, =F. Cuv.= H. N. Mamm. (fol.) iii. livr. lx. (♀) (1829). _Scopophorus montanus_, =Gray=, Knowsl. Men. p. 7, pl. v. (animal) (1850) (Gambia) (nec Cretzschm.). _Nanotragus nigricaudatus_, =Brooke=, P. Z. S. 1872, p. 874, pl. lxxv. (animal) (Gambia); =Ward=, Horn Meas. p. 81 (1892); =Lyd.= Horns and Hoofs, p. 219 (1893). _Oreotragus scoparius_, =Scl.= P. Z. S. 1867, p. 1039. _Neotragus nigricaudatus_, =Scl.= List An. Z. S. (8) p. 145 (1883). VERNACULAR NAME:--_Gebari_ or _Mahomet’s Antelope_ on the Gambia (_Whitfield_ fide _Gray_). Closely allied to _O. montana_, but still smaller, and the general colour greyer; the auricular gland as large as in _O. hastata_, and the tail with a blackish tuft, as in _O. scoparia_. Top of muzzle brown. Dimensions of the typical specimen, ♂:--Height at withers 21 inches; length of hind foot 10, of ear 3·4. _Hab._ Open districts of the Gambia and Senegal.