In the Cameroons the present species has been met with by the German collectors Preuss and Morgan, as recorded by Herr Matschie, and in Togoland, on the same authority, by Kling and Büttner. Thus there can be little doubt that Ogilby’s Duiker ranges along the woody littoral of Western Africa from Liberia to the Cameroons. Ogilby’s Duiker having been figured by Waterhouse Hawkins in the ‘Knowsley Menagerie’ it is probable that one or more living specimens of it were exhibited in that splendid collection, but we can find no record of examples of it ever having been received alive by the Zoological Society of London. Our figure of this species (Plate XVIII. fig. 2) was prepared by Mr. Smit, under Sir Victor Brooke’s directions, probably from specimens in the British Museum, but of this we have no certain evidence. _May, 1895._ 28. PETERS’S DUIKER. CEPHALOPHUS CALLIPYGUS, PET. _Cephalophus callipygus_, =Pet.= MB. Ak. Berl. 1876, p. 483, pls. iii. & iv. (animal and skull); =Thos.= P. Z. S. 1892, p. 422; =Lyd.= Horns and Hoofs, p. 211 (1893). VERNACULAR NAME:--_Mbindi_ in Mpongwe language, Gaboon (_Buchholz_). Size about that of _C. dorsalis_. General colour of body yellowish brown, becoming more rufous posteriorly. Forehead and crest rich rufous. Chin and throat white, rest of under surface yellowish grey. Back with a broad black dorsal band commencing behind the withers, broadening posteriorly, and involving the whole of the hams and backs of the hind legs down to the heels, and also the tail, with the exception of the extreme tip beneath, where the hairs are white-tipped. On the sides of the thighs, edging the black, the general body-colour becomes rich rufous. Horns short, directed backwards, lying below the level of the nasal profile. Dimensions:--♀. “Total length to tip of tail 46 inches, tail 8, ear 2·7.” Skull (taken from figure, and therefore only approximate): basal length 6·4 inches, anterior edge of orbit to muzzle (more or less decreased by perspective) 3·8. The description is compiled from Dr. Peters’s description and figure of this striking species, of which no specimen has come to England. _Hab._ Gaboon. The present Duiker, although evidently belonging to the same group as the preceding species, and probably most nearly allied to _C. dorsalis_, is separated by prominent well-marked characters, combining a brownish body and dark dorsal stripe with bright rufous markings on the forehead and haunches, which render it easily distinguishable.