CHARACTERS.--Head more pyramidal than in _C. cynosurus_, and the muzzle thinner; an angular patch of hair at the corner of each eye, pointing backwards; whiskers forming long and thick ear-tufts, directed backwards and partly concealing the ears; ears small; hands short and small. Face, ears, and lips dark {57}violet; region round the eyes livid flesh-colour; the superciliary band joining the whiskers white; top of the head, back as far as the rump, shoulders and arms greyish olive-green--the hairs ringed with greyish-black and pale yellow; whiskers, chin, breast, under surface of body, fore part of shoulders, the inner side of the limbs, and the under side of the tail, white; forearms, rump, and thighs grey, slightly washed with olive; hands and feet entirely grey; upper side of the tail greyish-black, the tip paler. Scrotal region coppery-green, covered with orange hairs. Distinguished from the Malbrouck by the form of the head, the greyer shade of the hair, and the colour of the scrotal region; and from _C. callitrichus_, described below, by the more sombre colour of its hair, the white superciliary band, and the long white whiskers. Length of body, about 19 inches; tail, 22 inches. DISTRIBUTION.--North-east Africa: throughout Abyssinia, Sennaar, and Kordofan, up to 4,000 feet. HABITS.--According to Dr. Blanford, this species is a true tree Monkey, and is very rarely seen except in the forest. "On the highlands of Abyssinia," he says, "I only once saw a flock--this was near Dildi, south of Lake Ashangi. I met with larger flocks on the Anseba, where they inhabited the high trees on the banks of the stream. The flocks seen were small, not exceeding twenty to thirty individuals. I had but few opportunities of observing their habits, but they appeared to differ but little from those of _Macacus_ or _Inuus_, except that _Cercopithecus_ is a quieter animal and less mischievous. In captivity they are well known as excessively docile and good tempered, and fairly intelligent." {58}XV. WERNER'S GUENON. CERCOPITHECUS WERNERI. _Cercopithecus werneri_, Geoffr., C. R., xxxi., p. 874 (1850); id., Arch. Mus., v., p. 539, pl. xxvii. (1851); Wagner, in Schreb. Säugeth. Suppl., v., p. 42 (1855); Sclater, P. Z. S., 1893, p. 258. CHARACTERS.--Nearly related to _C. sabæus_, but all the parts are olive-green where that species is greyish-green--the hairs being ringed with reddish-fawn and black; the former taking the place of the green rings in the hairs of the _C. sabæus_, and the black ones being much broader; the face black; the tail yellow at the tip as in _C. sabæus_. DISTRIBUTION.--The exact habitat of this species is unknown. XVI. THE GREEN GUENON. CERCOPITHECUS CALLITRICHUS. (_Plate XXVIII._) _Singe Verte_, Adanson, Voy. Sénég., p. 178 (1735). _Cercopithecus sabæa_ (nec Linn.), Erxleb., Syst. Regne An., p. 33 (1777). _Cercopithecus sabæus_, Wagner in Schreb. Säugeth., v., p. 40 (1855); Martin, Mammif. An., p. 519 (1841).