It was not to be expected that any representative of the Oribi would be found in Congoland or within the great forest-clad region of Western Africa. But when we come to the more open country of Senegal and the Gambia, an allied and nearly similar species appears upon the scene. The first evidence of its existence was given by F. Cuvier in 1829 by the publication of a figure and description of a female specimen under the name of the “Ourebi du Sénégal,” which was brought home alive by M. Perrotet, but died shortly after its arrival at Paris. Again, some years later, Whitfield, one of the collectors employed by Lord Derby, brought home from the Gambia a living example of an Antelope, which was subsequently figured in 1845 for the ‘Knowsley Menagerie’ by Waterhouse Hawkins. This figure was referred by Gray, who drew up the letterpress of that splendid work, to the Abyssinian Oribi next described, but there can be little doubt that it really belonged to the Gambian form. Whitfield gave the native name of this Antelope on the Gambia as “Gebari.” In May 1867 the Zoological Society received as a present from Mr. Charles B. Mosse a fine young male of this Oribi, which was eventually the means of making the species better known. It was at first referred by Sclater to the Cape Oribi, but afterwards considered to be more probably attributable to the Abyssinian _O. montana_. In 1872, however, when the animal was still living and quite adult, Sir Victor Brooke, at Sclater’s invitation, took up the question, and in a paper read before the Zoological Society, and subsequently published in their ‘Proceedings’ for that year, showed that neither of these determinations was correct, and that the Gambian animal belonged, in his opinion, to an unnamed species, which he proposed to call _Nanotragus nigricaudatus_. Although, like the two preceding species, the Gambian Oribi has a black tail, its smaller size seems to be sufficient to distinguish it from its congeners. Sir Victor had a water-colour drawing made of this animal by Wolf, from which both the figure published in the Zoological Society’s ‘Proceedings’ and the Plate now given (Plate XXVI.) have been prepared. This typical specimen is now in the British Museum, which has likewise two other young specimens from West Africa, without further details. Mr. Mosse, who brought the type specimen home himself, supplied Sir Victor with the information that he had procured it in March 1867, when it was only two or three months old, and that it had been caught on the banks of the Gambia about 70 or 80 miles from Bathurst, midway between that town and Macarthey’s Island. Mr. Mosse had never met with a second individual. In 1873 and 1876 the Zoological Society received female specimens of what were believed to be the same Antelope, but they did not live long in the Gardens. _December, 1895._ 44. THE ABYSSINIAN ORIBI. OUREBIA MONTANA (CRETZSCHM.).