_Cercopithecus grayi_, Fraser, Cat. Knowsl. Coll., p. 8 (1850); Gray, P. Z. S., 1868, p. 182; id., Cat. Monkeys Brit. Mus., p. 22 (1870); Sclater, P. Z. S., 1893, p. 256.
_Cercopithecus erxlebenii_, Dahlb. et Puch., Rev. et Mag. de Zool., 1856, p. 96; 1857, p. 196; Dahlb., Zool. Stud., p. 109, pl. 5 (1856); Gray, P. Z. S., 1868, p. 182; id., Cat. Monkeys Brit. Mus., p. 23 (1870; in part); Sclater, P. Z. S., 1871, p. 36; 1893, p. 254; 1894, p. 484.
_Cercopithecus pogonias_, Schlegel, Mus. Pays-Bas, vii., p. 82 (part).
CHARACTERS.--Face and ears naked, flesh-coloured; whiskers commencing under the eyes, bushy, yellow; the ears with a rufous or yellow tuft internally; head yellow, but interrupted by three broad black streaks, extending from above each eye and from the nose to the back of the head; back, anterior aspect of the thighs, and the sides yellowish rufous, darker towards the lower back--the hairs ringed with black and yellow, upper surface and entire terminal third of the tail black. Under surface of the body, inner side of the limbs, anterior aspect of the thighs and legs, and the under side of the basal two-thirds of the tail, yellow or rufous yellow; region of the anus white; external aspect of the fore-limbs black; the hands and feet black.
A female specimen of this species which lived for some years in the menagerie of Lord Derby at Knowsley, and died in 1836, is now in the Derby Museum, Liverpool. It is the type of _C. grayi_, with which _C. erxlebeni_ is identical.
{ 78}XXXIV. THE BEARDED GUENON. CERCOPITHECUS POGONIAS.
_Cercopithecus pogonias_, Bennett, P. Z. S., 1833, p. 67; Wagner in Schreber Säugeth. Suppl., v., p. 43 (1855); Lesson, Spec. Mamm., p. 74 (1840); Martin, Mammif. An., p. 543 (1841); Gray, P. Z. S., 1868, p. 182; id., Cat. Monkeys Brit. Mus., p. 23 (1870); Sclater, P. Z. S., 1893, p. 254; Schlegel, Mus. Pays-Bas, vii., p. 82 (1876).
CHARACTERS.--Similar to _C. grayi_, but differs in the yellow forehead being interrupted in the middle by only a few black hairs, and not by a streak; the whiskers paler; the back part of the head, the fore part of the back, and the sides grizzled, the hairs being black, ringed with white; while down the middle of the back to the base of the tail runs a broad black stripe.