Characters.—Of the same size as C. patas, and very similar to it. Fur above, and on the lower part of the limbs rufous, and on the lower part of the back, and under side of the tail, much darker rufous than elsewhere; nose white, not black as in the preceding species; shoulders and external aspect of arms rufous like the rest of the body, and not grey as in C. patas.
Distribution.—North-east Africa: Kordofan and Darfur, to a height of 3,000 feet above the sea. A specimen living in the Zoological Gardens in 1882 was stated to have come from Somali-land.
Allied to the Patas and the Nisnas is Peters' Guenon (Cercopithecus ochraceus, Peters, Reis. Mossamb. Säugeth., p. 2, pl. 1a), from Querimba, Mozambique, which has the upper side yellowish, and is probably but a variety of C. pyrrhonotus.
XXI. THE REDDISH-GREEN GUENON. CERCOPITHECUS RUFO-VIRIDIS.
Cercopithecus rufo-viridis, Geoffr., C. R., xv., p. 1038 (1842); id. Dict. Hist. Nat., iii., p. 307 (1849); Schl., Mus. Pays-Bas, vii., p. 78 (1876); Scl., P. Z. S., 1893, p. 258.
Chlorocebus rufo-viridis, Gray, Cat. Monkeys Brit. Mus., p. 25 (1870).
? Cercopithecus flavidus, Peters, Reis. Mossamb., p. 3, pl. i.b.
Characters.—Face black; a large frontal band white; head above olive-green; back green washed with rufous, gradually becoming bright rufous, slightly speckled with black on the sides of the body between the fore- and hind-limbs; shoulders and thighs grey, washed with green; the rest of the external aspect of the limbs grey; under side of body and inner side of limbs white; hands speckled black; the feet greyish; tail, dark grey above, pale grey below.
Distribution and Habits.—Unknown. The form described by Peters as C. flavidus comes from Mozambique.
IV. Cercopitheci Melanochiri.