1865. ] PRESBYTES AND COLOBUS. 741 
grounds, confirmed by the dissections of M. Otto* and Prof. Owent, 
who have described the very peculiar sacculated condition of the 
stomach belonging to this genus. 
Another group of African Monkeys, Colobus, Illigert, separated on 
account of the rudimental development of the thumbs of the an- 
terior extremities, illustrated in species by Ogilby § and other autho- 
rities, has also been shown by Prof. Owen|| in one species, the 
Colobus ursinus, Ogilby, to possess a pouched stomach and other 
viscera almost identical with that of Semnopithecus entellus. 
In the ‘ Proceedings’ of this Society for 1850, p. 77 and plate xvr., 
Dr. Gray defines and figures what he considers a new species of 
Semnopithecus (supposed to have come from West Africa) under the 
designation Presbytis albigena. This, in external appearance, bears 
resemblances to P. obscurus, although it is more like P. melalophus, 
but differing from this in being black, and, as he says, “can scarcely 
be a black variety of that species.” 
There was some doubt as to the African habitat of this new 
species, until M. du Chaillu brought home some skins of the 
animal from Gaboon, which cleared up that point. In remarking 
upon these specimens, a writer in the ‘ Natural History Review’ J 
expresses doubts as to the propriety of the species being classed 
along with the genus Preshytes. ‘The writer remarks—< Now that 
its African habitat is fully established, a more accurate examina- 
tion will probably show the necessity of removing this Monkey 
from the Asiatic group Presbytes, with which it has been hitherto 
arranged.” 
To a certain extent this has already been done, although clear 
reasons, so far as I am aware, have never been given. The stuffed 
skin of the typical specimen, mentioned above, is at present in the 
British Museum, marked Presbytes albiyena, Gray; but the skull 
of the same I find, on reference to the published ‘ Catalogue of Bones 
of Mammalia,’ 1861, p. 14, to be named Cercocebus albigena. 
A specimen of this rather rare creature having lately died at the 
Society’s Gardens, my attention has been called to its greater affinities 
with Cercocebus than that of Semnopithecus (Presbytes). The ani- 
mal in question was a female from Africa, about half-grown, and sent 
on approval by Mr. Cross, dealer, Liverpool. It lived in the Gar- 
dens for a period of two months, and died the latter end of October 
(1865). From the first it was weakly and delicate, but took its 
food tolerably well. 
As the creature was apparently younger than the typical specimen 
described by Dr. Gray, it may be worth while noting the differences. 
His description of colour and general appearance agrees closely ; but 
in the present one the throat, sides of neck, and front of chest were 
* Zoological Journal, vol. iii. p. 249. 
+ Transactions Zool. Soe. vol. i. p. 65. t Prodromus Syst. 
§ P. Z. 8. 1835, p. 97. | PB. ZS. 1841, p. 84. 
§| “The Fauna of Equatorial Africa” (N. H. R. 1861, p. 292), being a eri- 
tical review, chiefly based upon the works of the traveller M. P. B. du Chaillu 
and of the naturalist Dr. G. Hartlaub of Bremen. 
