726 MR. R. I. POCOCK — A REVISION OF [June 18, 



Key to the Sj^ecies. 



a. Wliiskers duskj' olive, almost the same colour as the top of the 

 head, though less yellow, directed hackwards, with scarcely a 



trace of ui:)ward trend nigroviridis. 



a'. "Whiskers, at least on the lower half of the cheeks, white or 



yellowish, and quite differently coloured from the top of the 



head, with marked backward and upward trend. 



h. No distinct white brow-hand ; yellow whiskers with a parting 



or whorl in front of the ear, half running up in front of 



that organ and half backwards beneath it, the ear being 



wholly exposed sahcens. 



h' . A white brow-band ; no parting- in whiskers, the long hairs 

 of which run backwards and upwards, so as to conceal the 

 ears if long enough. 



c. Tail shorter than body djamdjamensis. 



c'. Tail longer than body. 



d. Prevailing colour of dorsal surface chestnut-red, speckled 



black iiiatscJiiei. 



d'. Prevailing colour of dorsal surface yellowish, greenish, 



or gvey, speckled black. 



e. A considerable but varying quantity of silky-white 



hairs on the lips and chin ; scrotum slate-blue. 



f. Whiskers long and white, sharply defined in colour 



from the top of the head ; a tuft of hairs at root 



of tail athiops. 



f. Whiskers short and grizzled above, where they 

 blend in colour with the top of the head ; no tuft 



at root of tail cj/nosurns. 



e'. Face sooty black, no silky-white hairs on lips or chin. 



ff. Whiskers rather sharplj' defined in colour from 



the top of the head; a tuft of hairs at the root 



of the tail on each side ; no red at root of tail ; 



scrotum slate-blue ; hands and feet grey, end of 



tail 3'ellow tantalus. 



gi. Whiskers blending in colour with the top of the 

 head ; no tuft on each side of the root of the 

 tail, which is red below ; scrotum turquoise- 

 green ; hands, feet, and end of tail black or duskj' 

 in adult pygerytlirus. 



On account of the brevity of the descriptions of C. onatschiei 

 and C. djamdjanieiisis, I have been compelled to j)lace them 

 in the above-given key in such a manner that no clue to their 

 true affinity is supplied. They are probably ofishoots either ot 

 C. cethiops or C. 'pygei-ythrus. It v^ould perhajjs have better 

 expressed the affinities of the last four species if C. tantalus and 

 C. oithiops had been put under one heading, and C. cynositrussnid 

 C. fygerythrus under another. 



Cercopithecds SABiEUS Linn. (Plate XLII. fig. 1.) 



Simia sabcea Linn. Syst. Nat. ed. 12, i. p. 38, 1766 ; Schreber, 

 Saug. i. p. 100, pi. xviii., 1774; Audebert, Hist. Nat. Singes, 

 fam. lY. sect, ii., 1799 (in part. ; nee fig. iv.). 



Gercopitkecus sabcea Erxleben, Syst. Regni Anim, p. 33, 1777. 



Le Callitriche, F. Ouvier, Hist. Nat. Mamm. i. pi. iv., 1819 

 {(Jercopithecus sabceus in the Tabl. Gen. et Method, p. 1, 1824). 



