_Le Callitriche_, F. Cuv., Hist. Nat., Mamm., i., livr. iv. (Mars, 1819). _Simia sabæa_, Audebert, Singes, Fam. iv., Sect., ii., p. 7, fig. iv. (1797). _Cercopithecus callitrichus_, Is. Geoffr., Cat. Méth. Primates, p. 23 (1851); Schleg, Mus. Pays-Bas, vii., p. 73 (1876); Sclater, P. Z. S., 1866, p. 79; 1893, pp. 248, 616. _Chlorocebus sabæus_, Gray, Cat. Monkeys Brit. Mus., p. 25 (1870). PLATE XXVIII. [Illustration: GREEN GUENON.] {59}CHARACTERS.--Muzzle rather long; ears large, naked, and somewhat pointed behind; hairs on the side of the head long, thick, frill-like, and directed backwards toward the ears; hands and feet long, but the feet longer than the hands. Face, ears, palms, and soles, black; superciliary band bright yellow or white; head, back, shoulders, arms, and upper part of the forearms, the thighs, upper part of the legs, and upper side of the tail rich yellowish-green,--the hairs being ringed with broader bars of yellow, and narrower bars of black; external surface of the lower part of the fore- and hind-limbs grey, the hairs being ringed with white, or very pale yellow and black; cheeks, throat, under surface of the body, and inner side of the limbs, white, washed with yellow on the cheeks, throat, and along the mid-line of the belly. Tail tipped with a long tuft of bright yellow; under side of the tail greyish-green; hairs beneath the tail and on the scrotal region bright yellow; naked skin of the scrotal parts, green. Length of body, 24 inches; of tail, 29 inches. DISTRIBUTION.--West Africa: from Senegambia to the Niger. It is said to be now abundant in a wild state in the island of St. Kitts, in the West Indies, and Colonel Feilden identified it in Barbadoes. Into both of these islands it has been introduced from Africa, in the same way as into St. Jago, one of the Cape Verde Islands. HABITS.--The Green Monkeys frequent high trees in the great forests, living in small troops or sitting alone. They move about very noiselessly, and would seem to be devoid of voice, remaining silent even when attacked or wounded; although they knit their brows, gnash their teeth, and evince every sign of vexation and anger. This species is one of the commonest Monkeys introduced into Europe, as it appears to be able to stand, better than most of the other members of the genus, the northern climate. It has even bred in the Zoological {60}Gardens in London. It is very active and intelligent, and when young it is gentle and of a good disposition, but as it grows older it becomes treacherous, malicious, and savage. XVII. THE VERVET GUENON. CERCOPITHECUS PYGERYTHRUS. _Cercopithecus pygerythra_ (Le Vervet), F. Cuvier, Hist. Nat. Mamm., iii., livr. xxiv. (Janvier, 1821). _Cercopithecus pygerithræus_, Desmarest, Mamm., Suppl., p. 534 (1820).