General colour, dirty olive-grey--the hairs brown at the base, then yellowish-grey, ringed further up with black and yellowish-grey and tipped with black; the long and coarse hair {276}of the back lighter; chin greyish-white; the hind-limbs externally washed with brownish-yellow; the upper side of the hands and feet olive-yellow; tail brownish-grey; under side of body and inside of limbs silvery-grey. The bright olive-grey of the upper side and the silver-grey under side distinguish this species from all others; it is most nearly related to _C. babuin_. DISTRIBUTION.--East Africa, from the Rovuma river to the Pangani, and extending to the Victoria Nyanza. THE GELADA BABOONS. GENUS THEROPITHECUS. _Theropithecus_, Is. Geoffr., Arch. Mus., ii., p. 576 (1841). This genus has been established for the reception of two species which differ from the true Baboons (_Cynocephalus_) in having the nostrils placed on the side of the snout, instead of being terminal and opening, Dog-like, on the blunt face of the truncated nose. I. THE GELADA BABOON. THEROPITHECUS GELADA. _Macacus gelada_, Rüpp., Neue Wirbelth. Säugeth., p. 5, pl. 2 (1835); Schl., Mus. Pays Bas, vii., p. 107 (1876). _Theropithecus gelada_, Is. Geoffr., Arch. Mus., ii., p. 576 (1841). _Theropithecus senex_, Schimp. et Puch., Rev. et Mag. de Zool., 1857, p. 51. _Gelada rüppellii_, Gray, Cat. Monkeys Brit. Mus., p. 33 (1870); Garrod, P. Z. S., 1879, p. 451. CHARACTERS.--MALE.--Body large and massive; head oblong; face produced, rounded, and nude below the superciliary ridge; nose long and depressed in its middle region, but elevated at {277}the tip upon the deep upper lip; head crested, with long hair, rising from the superciliary ridge, and descending to a long and mantle-like mane on the back of the neck and shoulders, where the hair is longest, down to the loins behind, and as far as the elbow joints in front; whiskers very long, directed backwards over the ears, and downwards from the corners of the mouth; no beard; chin nude; a patch on the chest and one on the throat naked, separated from each other by a haired bar 1½ inches broad; tail long, round, erect for its basal third, then falling straight down as in other Baboons, and terminating in a long thick tuft. Face, hands, feet and callosities deep black; nude chest-spaces florid; hair of whiskers, neck-portion of mane, sides, arms, and lower margins of the mantle-like mane dark sooty chocolate-brown; breast, chest, shoulders, fore-arms, hind quarters and tail (except the terminal tuft) black; tail-tuft brownish-black, with a few white hairs; abdomen paler brown than the hair generally, though still dark; hair bordering the nude chest-spaces iron-grey from the presence of numerous short grey and white hairs; nipples close together on the lower nude chest-space; nails of hands longer than those of the feet. Length of the body, 29 inches; of tail, 24¾ inches; to tip of terminal tuft, 32 inches.