_Cercopithecus erythrotis_, Waterh., P. Z. S., 1838, p. 59; 1841, p. 71; Martin, Mammif. An., p. 535 (1841); Fraser, Zool. Typ., pl. iv. (1848); Wagn., in Schreb. Säugeth. Suppl., v., p. 49 (1855); Gray, P. Z. S., 1868, p. 182; id., Cat. Monkeys Brit. Mus., p. 21 (1870); Schlegel, Mus. Pays-Bas, vii., p. 70 (1876); Scl., P. Z. S., 1884, p. 176, 1893, p. 246. {53}CHARACTERS.--General colour of back, sides, and outer aspect of the hind-limbs, black, speckled with yellowish-grey, or with golden-yellow on the hinder part of the back--the hairs being black, ringed with yellow or gold respectively; face nearly nude, except for a few short hairs on the upper part of the nose; region round the eyes, livid blue; nose red; chin white; a black bar from the eye to the ear; below this a broad white whisker-streak on the cheeks, beneath which again there arises from the corner of the mouth and cheeks another black, yellow-ringed, tuft of hair; ears rusty-red internally; external aspect of the fore-limbs blackish; throat, under surface of the body, and inner side of the limbs greyish-white; tail bright rufous, except for a dark line along its upper surface; anal hairs bright red. Length of body, 17 inches; tail, 23 inches. DISTRIBUTION.--This rare and very beautiful Monkey has its home in the island of Fernando Po. XII. THE MOUSTACHED GUENON. CERCOPITHECUS CEPHUS. _Simia cephus_, Linn., Syst. Nat., i., p. 39 (1766). _Cercopithecus cephus_ (Moustac), F. Cuvier, Hist. Nat., Mamm., i., livr. xxvi. (1821); Martin, Mammif. An., p. 532 (1841); Wagner, in Schreber's Säugeth. Suppl., v., p. 49 (1855); Gray, P. Z. S., 1868, p. 182; id., Cat. Monkeys Brit. Mus., p. 20 (1870); Schleg., Mus. Pays-Bas, vii., p. 91 (1876); Scl., P. Z. S., 1893, p. 246. _Le moustac_, Audebert, Hist. Nat. Singes, Fam. iv., Sect, ii., p. 19, fig. xii.