2 40 THE OX AND ITS KINDRED 
Simpson on the left bank of the Kwilu River in the 
Belgian Congo. This river, which rises in Portuguese 
territory, runs nearly due north, and discharges into 
the Kwango, a tributary of the Kasai, which forms 
the most important affluent of the Congo. In the 
heavily fringed ears and general form of the horns 
the Kwilu buffalo approximates to the dwarf reddish 
B. c. nanus, but the horns of the largest bull killed by 
Mr. Simpson exceed in size any of the latter race of 
which measurements have been recorded, the right 
horn measuring 25f inches along the outer curve, and 
the left one 24J inches, the basal girth of the former 
being 16J inches, its maximum width 6f inches, and 
the expanse from tip to tip 13I- inches. In the largest 
cow the left horn measures 15 inches in length, with 
a girth of and an expanse of 8J inches. The 
horns incline upwards nearly in the plane of the face, 
and are more approximated at their bases than in the 
dwarf red buffalo. The colour of both cows and bulls 
is a pure brown, and thus much darker than the tawny 
red of nayitis ; the young only agreeing approximately 
in hue with the latter, and the cows being fully as 
dark as the bulls. Except in the bull of which the 
head is here figured, the fringes of the ears are tinged 
with tawny, with one white lock. In size the Kwilu 
buffalo slightly exceeds the specimens of the red race 
mounted in the British Museum. 
That the Kwilu buffalo, which I have named Bos 
caffer simpsoni^ is distinct from B. c. nanus, whose 
habitat includes Nigeria, Ashanti, and Sierra Leone, 
is indicated by its darker colour and larger and more 
approximated horns, the form of which does not agree 
with those of the latter. 
1 Proc. Zool. Soc, London, 1910, p. 993. 
