? Hylobates pileatus, Swinhoe, P. Z. S., 1870, p. 224 (nec Gray).
Hylobates hainanus, Thomas, Ann. & Mag. Nat. Hist. (6), ix., p. 145 (1892).
Characters.—Very closely related to H. hoolock, but differs by the entire absence of the white superciliary streak, the animal being jet black all over.
Distribution.—The island of Hainan.
Habits.—This species has not been seen alive in its native haunts by any European naturalist. Consul Swinhoe made many efforts to obtain a living specimen in the island of Hainan, but was unsuccessful. "I never ceased," he says, "to enquire after it. Every one knew that such an animal did exist, and many had seen it; but they all spoke of the great difficulty of keeping it alive. At Taipingsze (Central Hainan) the wonderful stories that were told about it showed that the Yuen was not often seen there. The magistrate of that district assured me, with a serious face, that it had the power of drawing into its body its long arm-bones, and that when it drew in one arm, it pushed out the other to such an extraordinary length, that he believed the two bones united in the body; and he said that the bones of the arm were used for chop-sticks." Mr. Swinhoe, however, published, in 1870, some curious extracts from the Chinese gazetteer of the Kiung-shan district of Hainan, which with little doubt relate to this interesting animal, of which skins have, since he wrote, been received at the British Museum, while a young individual lived for some months in 1893 in the Zoological Gardens of London, where it attracted much attention. The gazetteer says as follows: "Yuen: male black, female white; like a Macaque but larger, with the two fore-arms exceedingly long. Climbs to tree-tops and runs among them backwards and forwards with great agility. If it falls to the ground, it remains there like a log. Its delight is in scaling trees, as it cannot walk on the ground. Those desiring to rear it in confinement should keep it among trees; for the exhalations of the earth affect it with diarrhœa, causing death; a sure remedy for this, however, may be found in a draught made of the syrup of fried Foo-tsze (seeds of Abrus precatorius, Linn.)." The gazetteer then continues: "Hainan has also the Rock Yuen. It is small, about the bigness of one's fist. If allowed to drink water, it grows in size. This is also called Black Yuen, and is now likewise difficult to obtain."
Those who had an opportunity of observing the specimen that lived in the Zoological Gardens, will recall its extraordinary acrobatic feats, which were performed with marvellous precision and certainty, either with one or with both hands, and yet with the most careless air. It offered a striking contrast to an Orang-utan, which occupied the adjoining cage. This more robust Ape exhibited in its arms equally perfect powers of climbing; but it moved with the greatest circumspection, deliberation, and composure, exhibiting none of the volatile activity so characteristic of the Gibbons; but moving only one pair of its limbs at a time, and only when the other pair had firm hold of some support.
VII. THE SIAMANG GIBBON. HYLOBATES SYNDACTYLUS.
Pithecus syndactylus, Desmar., Mamm., p. 531 (1820).
Hylobates syndactylus, F. Cuv., Hist. Nat. Mammif., pl. iv. (1821); Is. Geoffr., Cat. Méth. Primates, p. 9 (1851); Bennett, Wanderings in N. S. Wales, ii., p. 151 (1834); Martin, Mammif. An., p. 420 (1841); Flower, Nat. Hist. Rev., 1863, p. 279 (cum fig.); Giebel, Z. Ges. Nat., p. 186 (1866); Schl., Mus. Pays-Bas, vii., p. 22 (1876); Anderson, Zool. Res. Exped. Yun-nan, p. 10 (1878; with full synonymy).
Simia syndactylus, Raffl., Tr. Linn. Soc., xiii., p. 241 (1822).