Speke notes that the “Nsumma” lies concealed “in the high grasses in the daytime, and only comes out to feed in the evening. The males are often found singly, but the females live in herds. It does not stand so high as the Waterbuck, but is rather more stoutly built.” We believe that the “Sing-sing” of Jackson, in the volumes of the Badminton Library on Big Game Shooting, is also referable to the present species. Mr. Jackson speaks of it as follows:--“The Sing-sing (also known to the natives as ‘Kuru’) resembles the Waterbuck in habits, but is easily distinguished from it by its darker colour, and by a considerable amount of rufous hair on the top of the head, as well as by an entirely white rump in place of the elliptical white band of the other. The horns are also, as a rule, longer and more massive than those of the Waterbuck, the horns of the latter never growing to the size that they do in South Africa. It is not met with until near Lake Baringo, and extends west to Uganda where it was obtained by Captains Speke and Grant. It is fairly plentiful in the open bush-country of Turkevel; but it does not appear to go about in such large herds as the Waterbuck. I have never seen more than five or six together, and more often a bull and two or three cows.” On the river running from the north into Lake Stephanie, Dr. Donaldson Smith met with a Waterbuck during his recent journey. Sclater has examined one of the heads that he brought home (see P. Z. S. 1895, p. 868) and has referred it without doubt to the present species. In German East Africa, Herr Matschie recognizes _Cobus defassa_ as well as _C. ellipsiprymnus_ and gives several localities for it on the authority of Neumann and Böhm. The former met with it on the west shores of the Lake Victoria, and the latter near Lake Tanganyika and in Ugalla and Uganda. Böhm in his manuscript says that this Waterbuck reminds one much of a Stag in its appearance and mode of life. It is generally met with in largish herds in which there is only one old male and several younger ones. Sometimes these herds are without females in their company, and occasionally old males are seen alone. They are very fond of water and are often seen standing deep in the mud of the rivers. At the same time they are frequently met with in dry forest and in open savannahs far from rivers. Like our Red Deer, they generally retire into the wood early in the day, even before sunrise, but on the other hand come out again into the open much earlier in the evening. When disturbed in the open country they retire straight into the wood. Herr Matschie points out that the present species differs from _C. unctuosus_ in having the face of a bright rufous colour, and is of opinion that Dr. Noack and Dr. Pagenstecher have wrongly referred the specimens of this species obtained by several German explorers to _C. unctuosus_ and _C. ellipsiprymnus_.