(P. Z. S. 1897, p. 455.)

We are not aware that any specimen of Angas’ Antelope has ever been brought to Europe alive, and it is by no means commonly met with in our museums. The British Museum contains an adult pair mounted, obtained in St. Lucia Bay by Mr. R. S. Fellowes in 1871, also specimens from the Pongolo River, Zululand, obtained by Mr. Eastwood, and from the Maputa River, obtained by Proudfoot. There are also in the National Collection the specimens from Nyasaland procured by Mr. Sharpe, Sir Harry Johnston, Mr. Crawshay, and Lieut. Oliver, of which we have made mention above. Finally, there is a good mounted pair of specimens obtained by Mr. Selous during his special expedition in quest of this Antelope.

Our principal illustration of Angas’ Antelope (Plate XCII.) was put upon the stone by Mr. Smit, under the directions of the late Sir Victor Brooke, from sketches made by Wolf, and was probably taken from the mounted specimens then in the British Museum. At the same time the woodcut (fig. 106, p. 146), also containing figures of both sexes, was prepared by Mr. Smit.

November, 1899.

Genus III. LIMNOTRAGUS (nom. nov.).

Type.
Hydrotragus, Gray, Cat. Rum. B. M. p. 49 (1872) (nec Fitz.)[11]L. spekii.

Medium or large-sized Antelopes allied to Tragelaphus, but with rougher and shaggier coats, longer legs, and with horns which more nearly approach those of Strepsiceros, as they show a strong tendency to assume a third twist. Further, Limnotragus differs strikingly from Tragelaphus and Strepsiceros in the structure of its feet, the hoofs being often nearly three times as long (measured along the front edge) as thick (measured along the margin of the pastern). Moreover, the skin which covers the back of the pastern is denuded of hair, and thick and horny, being practically of the same consistency as the upper rim of the posterior side of the hoof.

It is not without some hesitation that we refer to a separate genus those species of Tragelaphine Antelopes (hitherto placed in Tragelaphus) which have undergone certain special modifications of structure in adaptation to a semi-aquatic mode of life. In the species of Tragelaphus discussed in the preceding part of this work, as well as in all the other genera of Tragelaphinæ, the feet adhere to the digitigrade type characteristic of most of the ruminant artiodactyle Ungulates, retaining the short narrow hoofs and strong elastic ankles fitted for easy and swift progress over the firm soil of the veldt or woodland. In the species of Limnotragus, on the contrary, the feet are furnished with hoofs of relatively enormous length, which spread far apart at every step, and are obviously designed to enable their owner to pass over the soft soil of marshes and river-banks without sinking deeply into the ground. This modification is accompanied by an increase in the flexibility of the ankle-joints, which are capable of yielding to the weight of the body, so as to allow the false-hoofs and the smooth tough horny skin at the back of the pasterns to rest upon the soil, and thus to further augment the supporting area of the foot. It is these peculiarities in the structure of the feet, in conjunction with a length of limb exceeding that of other Tragelaphines, which impart to the species of Limnotragus that characteristic semiplantigrade aspect and that unusual awkwardness of gait so noticeable in these Antelopes when walking upon firm resisting ground.

Up to the present time three species referable to this genus have been described, namely, L. spekii from E. Africa, L. gratus from Tropical West Africa, and L. selousi from the valley of the Zambesi. Unfortunately there are not at present available materials from the different parts of the area over which the genus ranges, sufficient to enable us to determine satisfactorily the exact value to be assigned to these three forms. Consequently, although the evidence, so far as it goes, tends to show that the characters upon which they have been based may ultimately prove to have merely a subspecific importance, we prefer, for the time being, to allow them to take the rank that was originally assigned to them by their respective describers, and to arrange them as three species.

Range of the Genus. Congo Valley and Lake-districts of Southern and Eastern Africa.