the Oenus Cercocebus. 2S1 



Cercocehus agilis, aiul that Cercopithecus Wolfi, Orayi, pogo- 

 nius, and ni(jrij)es have been known for many years to be so 

 coloured beh)W *. j\Iy oidy reason for commenting now on 

 the fact is the p;reat interest attaching to the simihirity in the 

 colouring in the lower parts in all these monkeys, which 

 inhabit, broadly speaking, the same area of tropical West 

 Africa, namely the Congo. There must be an explanation of 

 this, but I am unable to suggest what it may be. 



5. Hagenbeck's Mangabey. 

 Cercocehus Uagenhecki, Lydd. 



Cercocehus Haqenbecki, Lvdekker, Novit. Zool. vii. p. 594 (lOOO) ; id. 

 op. cit. Tiii. pi. i. fig. 1 (1901). 



Loc. Upper Congo : exact area unknown. 



I am indebted to Mr. Rothschild for the chance of seeing 

 the type of this species. On the forehead, rather less tlian an 

 inch behind the brow, there is a very conspicuous parting, 

 whence the hairs radiate, those directed forwards forming a 

 conspicuous postsuperciliary fringe. This important feature, 

 attesting close relationship between C. Ilagenhecki and 

 C. agilisy is not mentioned in the description and only im- 

 perfectly suggested in the figure. The prevailing colour is a 

 smoky grey above, relieved on the head, whiskers, neck, 

 shoulders, and fore {)art of the back by the yellowish annula- 

 tion o£ the hairs. These annuli practically die out on the 

 sides of the body, the outer sides of the legs, and on the tail, 

 which is merely indistinctly speckled in its basal portion 

 above. The throat, chest, belly, and the inner sides of the 

 limbs are dirty greyish white. There is a complete absence 

 in the hair of the brown or fawn or rusty yellow hue men- 

 tioned by the two principal describers of C. agilis. It is 

 solely on this account that 1 separate the two forms specifi- 

 cally, altbough strongly suspecting they will ultimately prove 

 to be at most merely local races (tliat is to say, subspecies) of 

 one and the same species. But of this there is as yet no 

 proof. 



According to Mr. Lydekker, the eyelids were black in the 

 living type specimen, whereas another example living in the 

 Gardens at the same time had them flesh-coloured. In the 

 living specimens I have seen they are neither flesh-coloured 

 nor black, but somewhat greyish — that is to say, decidedly 

 darker than in C. (cthiopicuSy for example. I suspect they 

 are pale in the young and gradually darken with age, 



* The rufous belly of C. erythrorjaster must also be remembered in 

 this conuexiou. 



