GUEREZA, the native name of a long-tailed, black and white Abyssinian monkey, Colobus guereza (or C. abyssinicus), characterized by the white hairs forming a long pendent mantle. Other east African monkeys with a similar type of colouring, which, together with the wholly black west African C. satanas, collectively constitute the subgenus Guereza, may be included under the same title; and the name may be further extended to embrace all the African thumbless monkeys of the genus Colobus. These monkeys are the African representatives of the Indo-Malay langurs (Semnopithecus) , with which they agree in their slender build, long limbs and tail, and complex stomachs, although differing by the rudimentary thumb. The members of the subgenus Guereza present a transition from a wholly black animal (C. satanas) to one (C. caudalus) in which the sides of the face are white, and the whole flanks, as well as the tail, clothed with a long fringe of pure white hairs.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)