guishably the peculiar "Wow Wow” of the former,both in its slow and in its
remarkably rapid, trilling scale.
H y l o b a t e s m u l l e r i , Martin.
Hylobates concolor, Müller, Verhandl. over de Zool. ind. Archipel, 1841, p. 48 ; Blyth, Journ. As.
Soc. Beng. vol. x. 1841, p. 888; Martin, Nat. Hist. Quadr. 1841, p. 417; Schinz, Syn. Mamm.
vol. i. 1844, p. 81 ; Temminck, Coup d’oeil sur les Possess. Neerland. vol. iii. 1849 p. 408;
Hist. Nat. des Mammif. 1854, p. 55 (fig. of head); Wagner, Schreber, Säugeth. Suppl. vol. v.
1855, p. 17 (in part).
Hylobates mulleri, Martin, Nat. Hist. Quadr. 1841, p. 444 ; Temminck, Coup d’oeil sur les Possess.
Neerland. vol. iii. 1849, p. 408 ; Is. Geoff. St.-Hil. Cat. Méthod des Mammif. 1851, p. 7 ;
Arch, du Mus. vol. v. 1852, p. 584; Dahlbom, Stud. Zool. Fam. Reg. An. 1856, pp. 78, 75.
Hylobates funereus, Is. Geoff. St.-Hil. Compt. Rend. vol. xxxi. Dec. 1850, p. 874; Cat. Method, des
Mammif. Î851, p. 7 ; Arch, du Mus. vol. v. 1852, p. 582, pi. xxvi; Gervais, Hist. Nat. des
Mammif. 1854, p. 58, figure; Wagner, Schreber, Säugeth. Suppl. vol. v. 1855, p. 18.
This species varies from grey to dark yellowish hrown, but the grey in certain
lights appears pure ashy, and in others of a brownish tint. In some the chest and
abdomen are frequently of a lighter colour than the other parts, and of a brownish
yellow, and this seems to be the character of individuals met with on the west
coast of Borneo, while those inhabiting the meridional parts of the island have the
hands and fore part of the hody of a black-brown or reddish brown. In both of
these varieties there is a yellowish white supercilium. The last of them leads into
the Hylobates from the neighbouring islands of Sulu to the north-east of Borneo, in
which case the upper parts of the body are either grey or brownish, the lower part of
the back and the loins heing a little more clear than the rest. The outer surface of
the limhs, the feet, less the toes, the back part of the head, a narrow supraorbital
band, and the sides of the face, are paler than the other parts, and generally are ashy
grey, more or less pure. The anterior portion of the upper surface of the head and
the ventral aspect of the body are more or less brownish black, and the inner
aspect of the limbs is of the same tint in the greater part of its extent. The upper
surfaces of the hands and the toes are of the same colour, but the hlackish brown is
markedly mixed with grey. The face and under parts are black and the eyes are
brown.
Inhabits Borneo and the neighbouring islands of Sulu.
As has been remarked by Müller, this species is closely allied to H. leuciscus,
the general type of colouring being the same in both ; and this observation is also
applicable to H. pileatus, and in a more modified degree to H . agilis, all of these
Gibbons being characterised by the tendency to form a dark skull-cap, so to speak,
and by the colour of the dorsal region to pale on the loins ; while in H. mulleri and
H. pileatus there is the further disposition for the breast, belly, and inside of the
limbs to become darker than the hack ; but as this is also the character of the light-
coloured females of H. hoolocJc, much specific importance cannot be attached
•to it.
HYLOBATES. 9
H y l o b a t e s a g i l i s , F . C u v .
The Ounko, F. Cuv. Hist. Nat. des Mammif. June 1824, pis. vii, viii.
Pithecus lar, Geoff. St.-Hil. Ann. du Mus. vol. xix. 1812, p. 88.
Hylobates agilis, F. Cuv. Hist. Nat. des Mammif. Sept. 1821, pis. v, vi ; F. Cuv. Diet, des Sc. Nat.
vol. xxxvi. 1825, p. 288 ; Lesson, Man. de Mamm. 1827, p. 81 ; Temm. Monogr. de Mamm. vol. i.
1827, p. 18; Griffith, An. King. vol. v. 1827, p. 7 ; G. Cuv. Règ. An. nouv. éd. 1829, vol. i.
p. 90 ; Yarrell, Zool. Journ. vol. v. 1885, p. 187 ; Müller, Tijdsch. voor Natuur. Gesch. en Phys.
vol. ii. 1885, p. 826 ; Waterhouse, Cat. Mamm. Mus. Zool. Soc. Lond. 1888, 2nd ed. p. 3 ;
Blyth, Journ. As. Soc. Beng. vol. x. 1841, p. 888;, vol. xiü. 1844, p. 465; vol. xliv. 1875,
ex. no. p. 8; Cat. Mamm. As. Soc. Mus. 1868, p. 5.; Martin, Nat. Hist. Quad. 1841, pp. 416,
417, 425 (plate) ; Gray, Hand-list Mamm. B. M. 1843, p. 2; Müller und Schlegel, Verhand.
1889-44, p. 48; Cantor, Journ. As. Soc. vol. xv. 1846, p. 178; Fry, Proc. Zool. Soc. 1846,
p. 11; Ann. & Mag. Nat. Hist. vol. xvii. 1846, p. 484; Is. Geoff. St.-Hil. Cat. Méthod. des
Mammif. 1851, p. 7 ; Gervais, Hist. Nat. des Mammif. 1854, p. 53 (figure) ; Dahlbom, Stud.
Zool. Fam. Reg. An. 1856, pp. 74, 78, pi. iii. fig. 9 (clavicle); Gray, Cat. Monkeys and
Lemurs, B. M. 1870, p: 12.
Pithecus agilis, Desmarest, Mamm. 1820, p. 532.1.
Simia lar, Raffles, Trans. Linn. Soc. vol. xiii. 1822, p. 242 ; Vigors & Horsfield, Zool. Journ. vol. iv.
1828-29, p. 106; Fischer, Syn. Mamm. 1829 (in part), p. 12.
Hylobates leur, F. Cuv. Hist. Nat. des Mamm. June 1824, pis. 7, 8 ; Diet, des Sc. Nat. vol. xxxvi.
1825, p. 289; Lesson, Man. de Mamm. 1827, p. 80; Griffith, An. King. vol. v. 1827, p. 5;
Bory de St. Vincent, Diet. Class. d’Hist. Nat. vol. xii. 1827, p. 284 ; Is. Geoff. St.-Hil. Cours dé
l’Hist. Nat. des Mammif. 1829, p.~83 ; G. Cuv. Règ. An. nouv. éd. vol. i. 1829, p. 90 ; Sehtegel,
Essai sur la Physion. des Serpens, Pt. Gén. 1837, p. 237.
Hylobates variegatus, Temminck, Monogr. de Mamm. vol. i. 1827, p. xiii ; Müller, Tijdschr. voor
Natuur. Gesch. en Phys. vol. ii. 1885, p. 826 ; Wagner, Schreber, Säugeth. Suppl. vol. i. 1840,
p. 74; Lesson, Sp. des Mammif. 1840, p. 52; S. Müller, Verhandl. over de Zool. van den
Indisch. Arch. 1841, p. 15 ; Müller, Verhandl. 1889-44, p. 47 ; Horsfield, Cat. Mamm. E. Ind.
Co. Mus. 1851, p. 3; Wagner, Schreber, Säugeth. Suppl. vol. v. 1855, p. 16.
Hylobates raßei, Geoff. St.-Hil. Cours de l’Hist. Nat. des Mammif. 1829, p. 34 ; Zool. du Voyage
de Bélanger, 1834, p. 28; Compt. Rend. vol. xv. 1842, p. 716; Arch, du Mus. vol.ii. 1843,
p. 585 ; Müller, Tijdschr. voor Natuur. Gesch. en Phys. vol. ii. 1835, p. 326 ; Müll, und Schlegel,
Verhandl. 1889-44, p. 48 ; Wagner, Schreber, Säugeth. Suppl. vol. i. 1840, p 73.
Hylobates unko, Lesson (in part) Sp. des Mammif. 1840, p. 53.
Hylobates raßesii, Is. Geoff. St.-Hil. Cat. Méthod. des Mammif. 1851, p. 8; Gervais, Hist. Nat. des
Mammif. 1854, p. 58 (fig. of head); Dahlbom, Stud. Zool. Fam. Reg. An. 1856, pp. 74, 80 ;
Gray, Cat. Monkeys and Lemurs, B. M. 1870, p. 11.
The occiput, the back from immediately behind the shoulders, the flanks, the
hips, and the outer surfaces of the fore and hind limbs, paie yellow. . The shoulders,
chest, and belly, and the inside of the limbs and feet, dark brown. The eyebrows
and whiskers pale greyish. A few reddish hairs in the region of the genitalia.
Animals presenting the foregoing characters constitute the “ Ungka puti,” or
H. agilis, F. Cuv. ; but the Gibbons which are distinguished by the following particulars,
and which are known to the natives as " Ungka etam” (H. rafflesii, Geoff.),
appear to be only a dark variéty of H. agilis.
The type of this variety, which I have carefully compared with that of H. agilis,
1 From the circumstance that Desmarest quotes F. Cuvier as the first zoologist to recognise this species, it is evident that
the “ Mammologie,” although dated 1820, did not appear before September 1821.