HYLOBATES. 



Genus HYLOBATES, Illiger (1811). 



Size smaller than that of other anthropoid Apes ; the largest 

 species, H. syndactylus, not much exceeding three feet in height. 

 Body and limbs slender ; arms, hands, and feet exceedingly long, 

 the arms being so much longer than the legs that the hands reach 

 the ground when these animals stand upright on their feet a 

 position that is assumed habitually by this genus, and by this alone, 

 amongst the Simiidce, when walking. Thumb and great toe deeply 

 separated from the next digits. Ischial callosities (naked thickened 



Fig. 1. Skull of Hylobates lar. 



skin on each buttock) present, but small. There are generally 13 

 pairs of ribs, 5 lumbar, 3 sacral, and 3 or 4 caudal (coccygeal) ver- 

 tebrae ; so that there being, as usual, 7 cervical vertebrae, the verte- 

 bral formula is C. 7, D. 13, L. 5, S. 3, C. 3-4. 

 Dentition : i. |, c. ^, pm. |~, m. |^|. 



Synopsis of Indian and Burmese Species. 



A white or grey band across the eyebrows, re- 

 mainder of head and upper surface of feet 

 and hands the same colour as the body . , . . H. hoolock, p. 5. 



Hands, feet, and a ring of hair surrounding the 



face white or whitish H. lar, p. 7. 



1 . Hylobates hoolock. The Hoolock or white-browed Gibbon. 



Simia hoolock, Harlan, Trans. Am. Phil. Soc. iv, p. 52, pi. 2 (1834). 

 Hylobates hoolock, Blyth, Cat. p. 4 ; Sclater, P. Z. S. 1870, pi. v, 



fig. 2 ; Blyth, Mam. Birds Burma, p. 1 ; Anderson, An. Zool. 



lies. p. 1 ; id. Cat. p. 26. 



Uluk, Hindi ; Myouk-lwai-yyau and Tuboung, Burmese of Arakan. 



