10 SIMIADE. 
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. Geoffroy, placing faith in this character, separated a species, 
and formed for it a section of the genus, because 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. Rafftesii is smooth, 
without any tubercle; of H. leuciscus, with a single tubercle ; of H. 
lar and H. agilis, with two tubercles, which are thin and distinct in 
the first, and thick and lesy distinct in the second. He also says 
that the arms of H. Miillerit are longer than those of H. leuciscus. 
The species may be divided thus :— 
1. Hands and feet white ; nose rather elongate. 
a, Whiskers white. No. 1. 
&. Whiskers black. No. 2. 
2. Hands and feet like the rest of the body. 
a, Whiskers rigid, white; frontal band none. No. 3. 
b. Whiskers 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, Zinn. Simia lar, 
Gmel. Hylobates lar, Ilhger; Geoff. Simia longimana, Schreb. 
t. 2,1. Hylobates albimana, Horsf. Zool. Journ. 1820! 
Var. Yellowish white.— Cantor. 
Hylobates enteloides, Is. Geoff. Voy. Jacq. iv. p. 18, t. 184; Arch, du 
Mus. xi. t. 29. 
Hab. Malacca ; Siam; Burmah; Tenasserim, Cantor. 
“ Bladebones 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 individuals, 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 either 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 18 pairs. 
2. Hylobates pileatus. The Crowned Gibbon. B.M. 
Black ; shoulders and loins greyish ; hands, feet, and cireumfe- 
rence of the face, and a ring round the crown, white; whiskers 
black. ; 
