In his original diagnosis of _Limnotragus selousi_, Mr. Rothschild took the characters of the female from the specimen of this sex, from Lake Ngami, now living in the Zoological Society’s Gardens. In the specimens of _L. selousi_, however, from the Barotze River the immature female is of a rich red colour, inclining to black in the dorsal region, whereas the female from Lake Ngami was at the time of its arrival in England, when only half-grown, of the same nearly uniform tint as it is now when fully adult. Moreover, Mr. Selous, who has seen many skins of this Antelope from the Chobé, kindly informs us, in reply to an inquiry on this point, that the young are, according to his experience, never rufous in colour; although when newly born they are marked with white stripes and spots which subsequently disappear. We cannot explain these discrepancies at present, but must leave the matter as it stands for the investigation of future observers. _Hab._ Swamps of the district of Lake Ngami and similar localities on the Zambesi and its tributaries; thence north to Lake Mweru. The discovery of the existence of an Antelope of this water-loving group in South-west Africa was made even before Speke obtained his specimens of the last species in Karagweh. The well-known traveller, Charles John Andersson, met with the “Nakong,” as he calls it, during his explorations of Lake Ngami. In the volume descriptive of his four years’ wanderings, published in 1856, when calling attention to the great variety of large animals found in that district, more especially in the vicinity of the rivers, he mentions “two new species of Antelope, the _Nakong_ and the _Leché_,” and gives a lithographic plate, drawn by Wolf, to illustrate them as they appeared in their native haunts. Not having before him actual specimens of the former Antelope to draw from, the great artist had apparently only Andersson’s somewhat imperfect information upon which to prepare his likeness of the “Nakong.” He consequently gave a more prominent place in his illustration to the Leché (_Cobus lechee_), and hid the Nakong in a reed-bed, leaving only its kudu-like horns, of which Mr. Andersson’s friend, Col. Steele, was fortunately able to supply specimens, plainly visible. Andersson speaks of the Nakong as a “Waterbuck,” which, by means of its peculiarly long hoofs, not unfrequently attaining a length of six or seven inches, is able to traverse with great facility the reedy bogs and quagmires with which the country abounds. Another well-known African explorer, Thomas Baines, who penetrated far into South-west Africa from Walfisch Bay a few years later, also mentions the _Nakong_ as amongst several new or little-known Antelopes found in that district.