PATAS MONKEY, a West African species of the guenon monkeys (see Guenon, characterized by its large size, the foxy-red colour of the upper parts, blue face and white belly. Scientifically it is known as Cercopithecus (Erythrocebus) patas, and typifies a section of its genus of which the other representative is the East African nisnas (C. [E.] pyrrhonotus). See Primates.