682 MR. K. I. rococK — a revision of [June 18, 



The DIANA-GROUP. 



Pogonocehus Trouess., 1906. 



Face black, clothed with blacJc hairs, which spread on to the 

 cheeks, brows, and chin ; a narrow white brow-band (diadem) on 

 the forehead behind the superciliary black streak. A longer or 

 shorter tuft of white hairs, forming a beard, on the point of the 

 chin. A black band running from the corner of the eye to 

 the ear. Ears black, scantily clothed with white hairs. iSumniit 

 of head generally blacker than the body ; nape of neck, shoulders, 

 and sides of body dark ii-on-grey, speckled, the exposed portion of 

 the hair being black with two or three whitish annuli. A rich 

 brownish or blackish-red unspeckled band, broiid and posteriorly 

 expanding, extending from behind the shoulder to the root of the 

 tail and sharply demarcated from the surrounding iron-grey tint. 

 The posterior part of the jaw and of the cheek, the sides of the 

 neck and throat, the chest as far back as the mammte, and 

 the whole of the front of the fore leg halfway between the elbow 

 and the wrist white ; the white everywhere, except on the lower 

 arm, sharply defined from the surrounding black or grey. The 

 white hair on the cheek forming upi-unning whiskers which 

 partially overlap the ear. The fore leg, except for the white 

 strip above mentioned, black or nearly so both outside and 

 inside. Area of chest behind mammfe and belly jet-black. Outer 

 side of thigh greyish in front, white, yellow, or rufous behind up 

 to the root of the tail ; the rest, like the lower leg and foot, black. 

 The black area on the thigh separated from the anterior grey 

 area and from the red of the sacral area by a curving white 

 stripe, which extends forwards and downwards from the npper 

 rim of the ischial callosity. Inner surface of thigh and the 

 whole of the pubic and anal areas white, yellow, or rusty brown. 

 Tail black, with some reddish or grey hairs quite at the base. 



Distr. W. Africa : Liberia to Nigeria. 



The two known species belonging to this group may be 

 distinguished as follows : — 



a. Beard short, not more than an inch long, its basal portion covered 

 to a great extent by black hairs ; inner surface and back of thigh 

 up to root of tail bright rusty brown diana. 



a'. Beard from about two to three inches long, with scarcely any black 

 hairs at the base ; inner surface and back of thighs white, lemon- 

 or orange-yellow roloway. 



I have adopted Dr. Jentink's determination of these two species. 



Cercopithecus DIANA Linn. (Plate XLT. fig. 1.) 



Simla diana Linn. Syst. Nat. ed. 12, i. p. 38, 1766 ; Schreber, 

 Saug. i. p. 94, pi. xiv., 1774. 



Cercojnthecus diana Jentink, Notes Leyden Museum, xx. 

 p. 237, 1898 (nee auct. plurim.). 



Cercopithecus diana var. ignita Gray, Oat. Monkeys Brit. Mus. 

 p. 22, 1870. 



Loc. Liberia. 



