5. HYLOBATES. 11 



Onko, Tabraca, Hist, dc Siam, ii. p. 308, 1771. . Ilylobates pileatus, 

 Gray, Five. Zool. Soc. 18G1, p. 130, t. 21 ! 



Var. 1. Black. B # jf 



Var. 2. Dirty white ; crown, whiskers, and belly black. B. M. 



Var. 3. White; crown-spot and belly black; whiskers white. B. M. 



Var. 4. White, except the black bristles on the eyebrow. B. M. 



Hab. Siam, Mouhot. 



3. Hylobates leucogenys. The White-cheeked Gibbon. B. M. 



Black ; throat and sides of checks with a broad white spot of 

 spreading rigid hairs ; forehead black, without any frontal band. 



Ilylobates leucogenys, Oyilby, Proc. Zool. Soc. 1840, p. 20 ! Martin, 

 Monkeys, p. 445, 1. 1 



iiab. . 



4. Hylobates hoolock. The Indian Ilylobates. 



Black ; frontal band grey ; whiskers soft and fluffy, black or 

 greyish black. ]3 ^j 



Siniia hoolock, Harlan, Trans. Amcr. Phil. Soc. iv. p. 52, 1834 ; Is. 

 Geoff. Ilylobates hoolock, Lesson ; Martin, Monkeys, p. 438, 1". 274, 

 275. Ilylobates scyrites, Oyilby ! 



Var. ? Fur brownish. 13, j£ # 



Ilylobates fuscus, Lewis, Boston Journal N. II. i. p. 33. 



Var. Fur pale yellowish-brown; frontal band white; whiskers 

 busby, darker brown. 



I [ylobates choroniandus, Oyilby, Proc. Zool. Soc. 1837, p. 08 ! Martin 

 Quad. 442, f. ! ' 



Hab. India : Himalaya Mountains, Uardwiclce. 



5. Hylobates Rafflesii. The Malay Gibbon. B. M. 



Black ; frontal band white ; whiskers soft and fluffy, full black. 

 Simia lar, Raffles, Trans. Linn. Soc. xiii. p. 242. Hylobates Rafflesii, 

 Geoff. ; F. Cuv. Mamm. Lith. ; Is. Geoff. Ilylobates agilis, var., 

 Martin, Quad. p. 425, t. ! Hylobates concolor, Harlan, Joum. 

 Acad. N. S. Philad. v. p. 229. Ilylobates Harlani, Lesson. 



Hab. Sumatra. 



Var. Dark brown ; frontal band distinct. 

 Hylobates concolor, S. Miilhr, Vcrhand. 1. ! (not Harlan). Hylo- 

 bates Miilleri, Martin, Monkeys, i. p. 4; Is. Geoff. 

 Hab. Borneo. 



Dr. Dahlbom describos the skeloton, which has the bladcbone 

 smooth, without any tubercles. 



