6 SIMIIDJ3. 



Colour. Generally black throughout, with the exception of a 

 white or grey band across the eyebrows. This band is usually, but 

 not always, interrupted in the middle. Many individuals, how- 

 ever, both males and females, vary in colour from brownish black 

 to light yellowish grey, the frontal band being always conspicu- 

 ously paler. The crown, back, and outside of the limbs are often 

 paler-coloured than the lower parts of the body, the skin of the 

 naked part of the face below the frontal band being almost always 

 dark-coloured. Blyth thought that the males only were black, the 

 females always paler ; but this is certainly not the case; the females, 

 however, are more frequently pale-coloured than the males. 



Dimensions. From crown to rump about 20 inches, fore limb 

 (including hand) 23, hand alone 6, leg and foot 19, foot 6 ; height 

 from crown to heel about 32 inches. An adult male skull is 4-45 

 inches long from the occiput to the alveolar margin of the pre- 

 maxillaries at the base of the middle upper incisors, 3-35 in basal 

 length from the lower or anterior edge of the foramen magnum to 

 the same, and 2-9 in breadth across the widest part of the zygo- 

 matic arches. 



Distribution. The hill-ranges south of Assam ; Sylhet, Cachar, 

 Manipur, Irawadi valley near Bhamo, Chittagong, and Arakan in 

 hill-forest. It is uncertain how far the species is found to the east- 

 ward. According to Anderson it inhabits Martabau. Pemberton's 

 assertion that this species occurs at the base of the Himalayas in 

 the lower ranges of Bhutan is probably a mistake. The type 

 described by Dr. Harlan came from the Garo hills. 



Habits. Good accounts of this animal are given by Burrough, in 

 Harlan's original description, by Blyth and by Anderson. Like 

 most other Gibbons, the Hoolock is usually found associating in 

 flocks, often comprising fifty to a hundred individuals, or even 

 more. An old male, however, is occasionally found solitary. 



Gibbons are thoroughly arboreal, and Hoolocks are almost, if 

 not entirely, confined to hill-forest. They move chiefly by means 

 of their long arms, by which they swing themselves for prodigious 

 distances from branch to branch and from tree to tree. They de- 

 scend hill-sides at a surprising pace, their descent being accom- 

 plished by grasping bamboos or branches that bend beneath their 

 weight, and allow them to drop until they can seize the ends of 

 other bamboos or branches lower on the slope, and take another 

 mighty swing downwards. They also ascend with great rapidity, 

 swinging themselves from tree to tree. 



When walking on the ground, the Hoolock rests on its hind feet 

 alone, with the sole flat on the ground and the great toe widely 

 separated from the other digits. The arms are usually held up- 

 wards, sometimes horizontally, their great length giving the animal 

 a very peculiar aspect. Gibbons walk rather quickly, with a 

 waddling gait, and can easily be overtaken by men when on the 

 ground. 



The food of these Apes consists of fruit, leaves, young shoots, 

 spiders (of which they are very fond), insects, birds' eggs, and 



