5. HYLOBATES. 9 
Tribe II. HYLOBATINA. 
Body and limbs slender. Hands and feet long, slender. Buttocks 
callous. Hab. Asia and Asiatic islands. 
4, SIAMANGA. 
The arms very long, reaching to the feet; claws channelled ; 
the second and third toes united as far as the joint between the 
second and third phalanges; the throat very dilatile, of male naked, of 
female covered with hair. Skull with an elongated, compressed face, 
the lower jaw nearly as wide behind as in front. Hab. Asiatic 
islands. 
Siamanga, Gray, List Mamm. B, M.p. 2. Syndactylus, Boitard. 
Siamanga syndactyla. The Siamang. BLM. 
Black-woolly, chin and upper lip whitish. 
Var. White.— Raffles. 
Simia syndactyla, Linn. Trans. 1821! Pithecus syndactylus, Desm. 
Hylobates syndactylus, Horsf. ! Siamanga syndactyla, Gray, List 
Mamm. B. M. p. 2! 
Hab. Sumatra; Java. 
5. HYLOBATES. 
Arms reaching to the feet; claws channelled; second and third 
toes slightly united in the males, free in the females ; throat hairy; 
head round. Skull with a short, less compressed face; the lower jaw 
much narrower at the end of the tooth-line than in front. Hab. 
Asia and Asiatic islands. 
Gibbon, Buffon, 1766. Hylobates, Iviger, 1811. Brachiopithecus, 
partly, Blainv. 
The specimens of the genus are very variable in colour, and hence 
they have been divided into several species, the species being often 
described from a single individual. 
Some authors defend this practice by the fact that the natives of 
the country where they are found give them different names—that is, 
call a white specimen a White Unko, and a black one a Black Unko ; 
but this appears to be only as we call horses white, bay, or brown, 
without regarding them as distinct species. 
When several specimens are received from the same locality, as 
of H. lar from Malacca, or H. pileatus from Siam, the general 
colour of the animals varies from black to grey and to white. General 
Hardwicke figures the specimens found in the Himalaya as varying 
in the same manner. 
Dr. Cantor and other naturalists who have had the opportunity of 
examining these animals alive state that there is a great variation 
