10 SIMIAD^. 



in the extent to which the toes of the hind feet are united, especially 

 in the males of different specimens, and also sometimes they are 

 united on one foot and free on the other of the same animal. M. 

 Is. Geoffrey, placing faith in this character, separated a species, 

 and formed for it a section of the genus, hecause in one male speci- 

 men he had observed the second and middle toe united by a membrane 

 to the second articulation. 



The species are very much alike in appearance, and are variable 

 in colour from the same locality, so that one almost doubts their dis- 

 tinctness. Dr. Dahlbom has stated that there is a difference in the 

 skeletons : thus he says that the bladebone of H. Safflcsii is smooth, 

 without any tubercle ; of H. Uuciscus, with a single tubercle ; of R. 

 lar and H. agilis, with two tubercles, which are thin and distinct in 

 the first, and thick and less distinct in the second. He also says 

 that the arms of H. MuUerii are longer than those of U. leuciscus. 



The species may be divided thus : — 



1. Hands and feet white ; nose rather elongate. 

 «. Whiskers white. No. 1. 



b. Whiskers black. No. 2. 



2. Hands and feet hke the rest of the body. 



a. "Wliiskers rigid, white ; frontal band none. No, 3. 



b. AVTiiskers soft, fluffy ; frontal band white. Nos. 4, 5, 6, 7. 



1. Hylobates lar. The Gibbon. B. M. 



Black ; circumference of the face, and the hands and feet, white ; 

 whiskers white. 



Gibbon, Buffon, H. N. xiv. t. 2, 3. Homo lar, Linn. Simia lar, 

 Gmel. Ilylobates lar, Illiger ; Geoff. Simia longimana, Schreb. 

 t. 2, f. 1. Hylobates albimana, Horsf. Zoo!. Journ. 1820 ! 



Var. Yellowish white. — Cantor. 

 Hylobates enteloides, Is. Geoff. Voij. Jacq, iv. p. 13, t. 184: ; Arch, du 

 Mus. xi. t. 29. 



Hab. Malacca ; Siam ; Burmah ; Tenasserim, Cantor. 



" Bladeboues with two slender tubercles." — Dahlbom. 



Dr. Cantor observes, on H. lar, that the index and middle toes of 

 both or of one foot, in some inchviduals, of whatever sex or shade of co- 

 lour, are united by a broad web the whole length of the first phalange, 

 in some partially so, and in others not at all ; and that in H. agilis 

 the first phalange of the index and middle toe are in some individuals 

 of cither sex partially or entirely united by a web ; sometimes the 

 first phalange of the middle toe is partially united to the fourth (Cat. 

 Mamm. Malay, p. 3). The ribs vary from 12 to 13 pairs. 



2. Hylobates pileatus. The Crotuned Gibbon. B. M. 



Black ; shoulders and loins greyish ; hands, feet, and circumfe- 

 rence of the face, and a ring round the crown, white ; whiskers 

 black. 



