6 ERYTHROCEBUS 
occur. At Lake Chad, Nigeria, E. saNNio is met with, the only species 
yet discovered in that large Province, and in Cameroon, E. LANGELDI 
was obtained. The locality of one species E. cIRCUMCINCTUs is quite 
unknown, nor is there any specimen extant, a figure given by Reichen- 
bach being the only evidence we have of its existence. 
KEY TO THE SPECIES. 
A. Brow band black. 
a. Shoulders not black. 
a. Thighs not black. 
a... Nese black ss. ...s% 0 ceee ere fae E. patas. 
b.” Nose white. | 
wr 
a. Rump and tail above ochra- 
CeOUS: : -aem ana d- eho E. pyrrhonotus. 
b.’” Rump vinaceous rufous, grad- 
ing into. bay on tail. shel 1k. E. formosus. - 
b. Shoulders mostly black. 
a. Thighs mostly reddish. 
a.” Chin white. 
LA 
a. Outer side of forearm to hand 
grizzled black and white..... E. poliopheus. 
b.”” Outer side of forearm to hand 
white. 
a.” 4 Nose aubite, ii. ae ae E. whitei. 
b.”” Nose black. 
a? EGhinwhate rz. e. « .4cnndes E. kerstingt. 
b.o 2 KORA alee ace yc. a eae eae E. zechi. 
c.” Outer side of forearm to hand 
LGD ig GROMER SAM a Tec ok MRR NP E. langeldi. 
b.’ Thighs mostly all white. 
Qi: General color:rich baysiech. eUasinw.e E. albigenis. 
b.” General color speckled orange buff, 4 
atl ‘Witte... 2.40. widsath satis wea- mt E. sannio. 
Bb. - Brow. band whthe, (seas adh coo denna b Gosh E. circumeinctus. 
Gax No brow: Dand . SAjn4 a as 8.45408 ee oa 400% E. baumstarki. 
ERYTHROCEBUS PATAS (Schreber). 
Simia patas Schreb., Saugth., I, 1775, p. 98, pl. XVI; Bodd., 
Elench. Anim., 1784, p. 59. 
Cercopithecus patas Erxl., Syst. Regn. Anim., 1777, p. 34; Less., 
