415 



the other toes conjointly. In some species, the first and second finger 

 (of the foot) are, more or less, united together ; this union, in the Sia- 

 mang, is carried to the last joint. Sir T. S. Raffles, who first pointed 

 272 out this peculiarity in the 



Siamang, conceived it to 

 be restricted to this spe- 

 cies, which is certainly not 

 the case. Much less cor- 

 rect, therefore, is the asser- 

 tion of M. Duvaucel, that 

 it is a sexual difference 

 peculiar to the female, as 

 he remarks more particu- 

 larly with reference to the 

 Ungka-puti and the Ungka- 

 etam. It appears, how- 

 ever, in the latter animals, 

 to be a variable character, 

 Foot of Gibbon sometimes present, some- 



times not to be discerned ; and hence, probably, Sir. T. S. Raffles denied 

 its existence in any species, except the Siamang.* 



With regard to the lower extremities in the Gibbons, they are very 

 short, and bowed in ; and the ankle-joint has that inward tournure so 

 advantageous to an arboreal animal ; but the hip-joint is secured by the 

 ligamentum teres. 



The Gibbons are clothed with deep, thick fur, softer in some species 

 than in others ; on the chest and abdomen it is much thinner than on any 

 other part of the body ; that on the fore-arms is mostly reverted to the 

 elbows, where, meeting the hair of the humerus, it forms a peak. In the 

 Ungka-puti, however, the hair of the fore-arms is inclined forward in the 

 ordinary manner ; in the white-handed Gibbon it is nearly erect, with an 

 inclination forward, but less decidedly than in the Ungka-puti. 



In one species, the brown whiskered Gibbon (H. Choromandus), the 

 hair of the head radiates from a centre on the crown ; in the rest, it falls 

 back from the forehead, without any radiating point. In the white- 

 handed Gibbon (which has scarcely any whiskers), it is somewhat erect, 

 from its shortness and closeness. The prevailing colours in the animals 

 of the present genus are black, more or less intense, dull grey, and dirty 

 straw yellow : white occurs only in a limited degree. 



It is very remarkable that, as far as is known, one species only, the 



* It is interesting to find a recurrence of this character in the tree-climbing Phalangers of Australia. 

 The syndactylous group of birds (Kingfishers, Todies, &c.) also present an analogous conformation; 

 but in these the outermost or middle of the three anterior toes are thus conjoined. 



