SPECIES OF GIBBONS. 35 



III. GENUS HYLOBATES. 



The Gibbons. — The third genus of the man-Hke apes is that of the 

 long-armed apes which are commonly called Gibbons. The scientific 

 name Hylobates, or "forest walkers," from the Greek hylc "a wood," 

 and baino "to walk,"was given them from the fact that they are chiefly 

 found in the dense forests of India and the Eastern Archipelago. For 

 life in the forest they are admirably adapted by the length of their fore- 

 arms. 



The Gibbons are divided into Seven Speeies, some of which attain a 

 considerable size, although not exceeding three feet and a half They 

 are the only Anthropoid apes possessing gluteal callosities. The body, 

 although the breast is well rounded, seems slender, owing to the thinness 

 of the flanks; the hinder limbs are much shorter than the fore limbs, and 

 in some species the long hand is characterized by a growing together 

 of the index and middle finger. The head is small and egg-shaped, 

 the face human-like, the tail is not visible externally. A silk fur 

 covers their bodies, the colors being principally brown, brownish-gray, 

 or straw-color. 



THE HULOCK. 



The HuLOCK, Hylobates hidock, (Plate I), bears clearly the marks of 

 the genus. It has no air-sack and the fingers do not grow together. 

 Its hair is coal-black except a white line across the forehead ; in the 

 young it is dark-brown, and ash-gray on the back. The HuLOCK 

 inhabits Farther India and Bengal, especially the woody banks of the 

 Brahmapootra river. 



THE LAR, UNKO AND WAUWAU. 



These species are natives of Malacca and Siam. The Lar, Hylobates 

 lar, is almost as large as the Hulock. The prevailing color is a dark- 

 gray, the hands are of a whitish-gray on the upper, but black on the 

 lower surface. 



The Unko, Hylobates rafflesii, is distinguished from the Hulock 

 anatomically by the possession of fourteen pairs of ribs. Its face 

 and coat are black, inclining to reddish-brown on the back ; the 



