DIANA MONKEY, a west African guenon monkey (q.v.), taking its name, Cercopithecus diana, from the white crescent on the forehead ; another characteristic feature being the pointed white beard. The general colour is greyish, with a deep tinge of chestnut on the hinder back. Together with C. neglectus of east and central Africa, C. ignitus of Liberia, and C. roloway of the Gold Coast, the diana represents the subgenus Pogonocebus.