_Cercopithecus erythrogaster_, Gray, P. Z. S., 1866, p. 169, pl. xvi., 1868, p. 182; id., Cat. Monkeys Brit. Mus., p. 128 (1870); Murie, P. Z. S., 1866, p. 380; Schleg., Mus. Pays-Bas, vii., p. 69 (1876); Sclater, P. Z. S., 1893, p. 252, 1894, p. 1. CHARACTERS.--Fur blackish, speckled with yellow, especially on the head, the hairs being black ringed with yellow; face black; nose-spot white; moustache and frontal band from the temple to the ears black; on each cheek a whitish-yellow spot; whiskers, beard, throat, and sides of neck yellowish-white; chest and under surface of body rufous; inner side of the front of the thighs, and under side of the tail greyish-white; outer aspect of thighs and hind legs grey, speckled with black. Length of body, 13½ inches; of tail, 16 inches. In the young female the top of the head is yellowish, this colour extending towards the nape. DISTRIBUTION.--West Africa. This species has been only once exhibited in the Zoological Gardens of London, viz., in 1866, but recently, according to Dr. Sclater, a specimen lived for a short time in the Zoological Gardens of Rotterdam. HABITS.--Nothing is known of the habits of the Red-bellied Guenon in a state of nature; but Dr. Murie has written of the one that lived for two months in the Zoological Gardens: "Its nature appeared mild and harmless, by no means grave or sedate, indeed rather inclined to be lively and playful, with but little disposition to be quarrelsome. The keeper noticed that it appeared timid, and somewhat distrustful of its more romping companions, but freely approached him, and when {47}taking food out of his hand seemed pleased, and gently played with his fingers without attempting to bite." IV. BÜTTIKOFER'S GUENON. CERCOPITHECUS BUETTIKOFERI. _Cercopithecus buettikoferi_, Jentink, Notes, Leyd. Mus., viii., p. 56 (1886); Sclater, P. Z. S., 1893, p. 244. CHARACTERS.--Büttikofer's Guenon agrees in all respects with _C. petaurista_, but wants the black band from ear to ear round the vertex. Of this band "there is no trace, in a series of eight specimens, containing adults and young, males and females" (_Jentink_). Irides brown. DISTRIBUTION.--West Africa: Liberia. V. MARTIN'S GUENON. CERCOPITHECUS MARTINI. _Cercopithecus martini_, Waterh., P. Z. S., 1838, p. 58; 1841, p. 71; Martin, Mammif. Anim., p. 542 (1841); Gray, Cat. Monkeys Brit. Mus., p. 21 (1870); Scl., P. Z. S., 1884, p. 176, pl. xiv.; 1893, p. 245. _Cercopithecus nictitans_, Schl., Mus. Pays-Bas, vii., p. 89 (1876).