Whether the horn from Sierra Leone, figured and described by Afzelius in his essay on Antelopes, published in the ‘Nova Acta’ of the Society of Sciences of Upsala in 1795, and subsequently referred to by Hamilton Smith and other authors, really belonged to the present species is somewhat uncertain, although such may very possibly have been the case. The first trustworthy introduction of this species to scientific literature is therefore due to Ogilby, a well-known authority on the Ruminants, who in 1836 established his _Antilope eurycerus_ in a paper read before the Zoological Society of London on November the 22nd of that year. Ogilby’s materials consisted of “two pairs of horns, one attached to the skull, the other to the integuments of the head,” which had then “long existed in the Society’s collection.” Their origin was unknown, but they were believed to have come from Western Africa. These specimens, we may add, are now in the British Museum, to which they were transferred by the Zoological Society in 1858. One of the pairs was figured by Gray in the volume of the ‘Gleanings from the Knowsley Menagerie,’ published in 1850. In 1853 Temminck recorded the existence of a pair of horns of this species in the Leyden Museum, and gave its vernacular name as the “Trommé” of the Mandingos of Western Africa. With this exception no addition appears to have been made to our knowledge of this Antelope until 1860, when Mr. P. B. Du Chaillu, who had met with it during his excursions in the interior of Gaboon from 1856 to 1859, described it before the Boston Society of Natural History as a new species, under the name _Tragelaphus albo-virgatus_. In the report of his paper published in the ‘Proceedings’ of that Society we find its locality given as the “forests about the head-waters of the Fernand-Vaz in the Aschankolo Mountains, 60 miles south of the Equator, and 140 from the coast.” In the narrative of his travels, published in 1861, Mr. Du Chaillu writes of the same Antelope as belonging to the fauna of the “Rembo Region,” the Rembo being one of the rivers that flows from these mountains, and tells us that it is “very shy, swift of foot, and exceedingly graceful in its motions.” The full-page steel engraving that accompanies these remarks, which, by the kindness of Messrs. Murray, we are enabled to reproduce (fig. 103, p. 134), is stated to have been taken from a well-preserved specimen in his collection. The native name is given as “Bongo.” After describing his specimens in America, Mr. Du Chaillu brought them to this country, and disposed of them to the British Museum. [Illustration: Fig. 103. The Bongo Antelope. (From Du Chaillu’s ‘Travels in Equatorial Africa,’ p. 306.) ]