MAMMALS COLLECTED IN SIAM. 339 
and 2127/C.B.K. Collected at Lat Bua Kao, East Siam on 8th 
and 11th October, 1916. 
Characters. A grey leaf-monkey with dark hands and feet; 
pelage not grizzled. A whorl of hair on the occiput and an erect 
crest, forming either an upstanding tuft or a median ridge. 
Colour. Male:—A row of stiff black hairs above the eyes, 
Crown and temples somewhat fuscous. Whiskers, shoulders and 
upper parts nearly neutral-grey slightly washed with wood-brown 
giving a general colour-effect of silvered mouse-grey. Rump, lower 
limbs and base of tail silvery, rest of tail deep mouse-grey slightly 
washed with wood-brown and silvered ; front of thighs deep mouse- 
grey ; feet brownish-black. Throat, chest and forelimbs deep mouse- 
grey, the latter gradually darkening over the forearms to brownish 
black on the hands. Abdomen and inner side of upper arms 
slightly paler than chest, the inner sides of the forearms darker but 
less so than on their outer aspect. 
Type female as in the male, but the whiskers and upper 
surface — especially the occiput, neck and shoulders — paler, more 
silvery and with the wood-brown wash very distinct on the median 
line of the upper back, while the undersurface is also paler, being 
of a yellowish silvery tone. The feet are slightly grizzled. 
A slightly younger female (2128), and a juvenile female 
(2129), are rather deeper mouse-grey than the male, and more 
washed above with wood-brown than either of the types; in the 
older of the two the thighs are also washed with wood-brown and 
the distal half of the tail is tinged beneath with ferruginous. A 
yet more juvenile male (2130) is darker still, being almost deep 
quaker-drab and scarcely silvered at all, except on the chest, which 
is silvery white. 
These animals might alternatively perhaps be described as 
quaker-drab, but their colour is difficult to express as it varies with 
the incidence of light, and the above descriptions have been drawn 
up with the specimens placed near a window, heads pointing to the 
left. 
Measurements. External measurements of the types taken in 
VOL. III, NO. 4, 1919, 
