SIMIID^E 



729 



having a better developed chin and wider sternum than any other 

 Ape, and differs from the other members of the genus by the 

 circumstance that the second and third digits of the pes are united 

 by skin as far as 

 their last joints. 

 Exclusive of this 

 species, the Gibbons 

 differ but little from 

 one another in size 

 and general con- 

 formation, and since 

 the colour of indi- 

 viduals undoubtedly 

 referable to a single 

 species is remarkably 

 variable, there is 

 much uncertainty 

 about the number of 

 species, and much 

 confusion in the 

 nomenclature. 

 Among well-marked 

 species we may 

 mention the Hoolock 

 (//. hoolock), ranging 

 from the South of 

 Assam through 

 Sylhet and Cachar to 

 the Irawadi Valley 

 near Bhamo, the 

 White-handed Gib- 

 bon (H. lar, Fig. 

 350), which is found 

 in Tenasserim and 

 throughout Malay- 

 ana, the Dun-coloured Gibbon (//. entelloides, Fig. 351) of Malayana, 

 and the Tufted Gibbon (H. pileatus) of Siam and Cambogia. 



The following account of the habits of the Gibbons is taken 

 from Mr. W. T. Blanford's Mammals of British India. " 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 descend hillsides 

 at a surprising pace, their descent being accomplished 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 



Fio. 350. The White-handed Gibbon (Hylobates lar). From 

 Blanford, Mammals of British India, p. 8. 



