_Hylobates leucogenys_, Ogilby, P. Z. S., 1840, p. 20; Blyth, J. A. S.
Beng., x., p. 838 (1841); Martin, Mammif. Anim., p. 445, _cum fig._
(1841); Is. Geoffr., C. R., xv., p. 717 (1842); id., Arch. Mus., ii., p.
535 (1843); Gray, Cat. Monkeys Brit. Mus., p. 11 (1870); Schl., Mus.
Pays-Bas, vii., p. 13 (1876); Scl., P. Z. S., 1877, p. 679, pl. lxx.;
Anderson, Zool. Res. Exped. Yun-nan, p. 6 (1878; with synonymy).
CHARACTERS.--Fur glossy, thick, and woolly; the hair of the upper and back
part of the head standing vertically erect; the face, chin, and ears black;
round the face from the level of the eyes and meeting below the chin runs a
white border, forming {159}whiskers and beard; elsewhere the colour is
entirely black. Length of the body, 26 inches.
DISTRIBUTION.--Siam.
HABITS.--This rare species is very active and gentle in confinement. It
will hang suspended, as Martin observed in the first specimen brought to
Europe, from a branch for the whole day, except when asleep or reposing.
The type specimen was described in 1840,--its skin being preserved in the
British Museum; but it was not till 1877--after a lapse of thirty-seven
years--that a second specimen was brought to this country. It was sent to
the Zoological Gardens by Mr. W. H. Newman, H.B.M. Consul at Bankok.