KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 48. N:O 5. 35 
Among the differences between this species and C. albotorquatus, NEUMANN! 
mentions the »red anal region» of the latter. In consequence of this PococKr” states 
that in skins from >»the IKedong» Escarpment> (probable the same as the present 
Escarpment railroad station), and such from Boromo »a considerable quantity of 
brownish red hair» is to be found at the sides of the ischial callosities, while in spe- 
cimens from Nairobi this is less well developed. PococKk appears therefore to be in 
doubt whether »more than one species is here involved». The present material 
appears to throw light on this question. In four fine old males from the forest at 
Escarpment station the red of the ischial and anal regions is absent except in the 
specimen with the shortest canines and smallest skull which thus may be assumed 
to be the youngest, although it is fully adult. In a younger female from the same 
locality the red is well developed in the region mentioned. The same is the case 
with all the specimens from Nairobi, although it is least abundant in the two oldest 
females, and best developed in a quite young animal in which the first molar has 
not yet appeared. In this latter the red hair of the anal region extend even to 
the root of the tail. To judge from these facts the presence of red hair in the 
anal and ischial regions of this species evidently is a juvenile charasteristic which, 
more or less completely, is lost during the ontogenetic development when the animals 
reach full maturity or old age. This accounts for the seeming irregularity in its 
development. There is also very little probability that two allied species of Cercopi- 
thecus should live the one at Escarpment and on Kenia, and the other in the forests 
near Nairobi. 
There is a great difference in size between males and females of this species. 
This may be seen from the following measurements: 
| | i 
Greatest Basicranial | Condylobasal 
length length | length 
| | 
Adult male from Escarpment. . . . .. . . . « « SN 116: mm; I 88,5 mm; 95,5 mm. | 
» så & SORUFAREOD = By. A. or OIRIGBL 115 > Ro, SON. Ar | 
» » » AESETRSTE EI bröSIVA > Re SMSOSIEFES SAIT NE 114 » INA 820ra 92,0 » | 
> I föneo törn Non. Sid dT Arad yr PI: bydtå > 77,3 | 
ller NY SKAR SE SR > Fr 100 GER OS AN FESISIES Fra | Ar es JAN Ke 
» > » RA LR ro ND NE Re 3 Dra Bra SEE I NRO FORA å ER | 68,0 » | 16,4 
DOLLMAN has named a female specimen from Nairobi Cercopithecus kolbi nubi- 
lus.” This is said to be distinguished by its »much duller colour of the dorsal sur- 
face lighter under parts, and less conspicuous white collar». All these characteristics 
are rather variable. I have in this collection specimens from Nairobi which are just 
as bright in their colours as specimens from Escarpment and Kenia which, however, 
as living at a higher altitude have a somewhat thicker and longer fur. Some of the 
3 
Proc. Zool. Soc. London 1902 Vol. II pl. I p. 144. 
Proc. Zool. Soc. London 1907 p. 703. 
Ann. dör Mag... NatsEist, Ser, 8. Nol, Vv. L9LOp; 202, 
& NN MH 
