156 BYLOBATE'S 
manent, as the white hands and feet of H. Lar, but no dependence can 
be placed upon the general hue of the pelage at any time. Uniformity 
of coloring is not one of the tenets of the species of Hytosates, and 
so far as the hues of their coats are concerned each one wears whatever 
seems best in his own eyes. The quantity and depth of color pigments 
among the members of the different species is a most uncertain quality, 
and rarely do two individuals possess them in the same degree, other- 
wise these many and extreme variations are quite unaccountable. 
Mr. Pocock states that the voice of the Hainan Gibbon “is quite 
different from that of the Hoolock. It has a high pitched trill all on 
the same note, and shriller even than the high note of the Hoolock’s 
cry. It consists of from about three to six distinct cries repeated in 
very rapid succession, suggesting almost, production by vibration of 
the tongue, although as a matter of fact, I believe the lips alone are 
instrumental in producing the effect. There is then a momentary 
pause, after which the cry is repeated. It may perhaps be represented 
in the following way: hoo, hoo, hoo, hoo—hoo, hoo, hoo—hoo, 
hoo, hoo, hoo—etc. The Hoolock on the contrary cries as follows: 
hah, hoo, hah, hoo, hah, hah, hoo, hah. The ‘hoo’ is on a lower 
note than the ‘hah,’ with which the cry frequently ends. 
“The ordinary expression of anger or remonstrance in the Hainan 
Gibbon is a prolonged and guttural grunt, which is repeated rapidly 
and often, and frequently interspersed with a kind of warble when 
the excitement rises. 
“Both the Hoolock and Lar Gibbon in the Gardens drink habit- 
ually by dipping the back of the hand and knuckles into the dish and 
licking the water off. They do not scoop it up in the strict sense of the 
word at all. The Hainan Gibbon, on the contrary, almost invariably 
drinks direct with her mouth, only very rarely using her left hand for 
the purpose. It is possible she may have abandoned the habit of 
employing the hand at the time when an injury deprived her of the 
use of her right arm, and since the left is frequently occupied in sup- 
porting herself upon the bars or perches in the cage, she has no hand 
available for the purpose of drinking without quitting her hold.” 
HYLOBATES HOOLOCK Harlan. 
Simia hoolock Harlan, Trans. Amer. Phil. Benes IV, New Ser., 
1834, p. 52, pl. IT. 
Hylobates choromandus Ogilby, Proc. Zool. Soc. Lond., 1837, p. 
689; Waterh., Cat. Mamm. Mus. Zool. Soc. Lond., 1838, 
p. 3; Less., Spec. Mamm., 1840, p. 54; Martin, Mammif. 
