which are generally black, and the persistence of the former colour throughout
life in some females, and perhaps also in some males, are facts of considerable
interest, and should not be lost sight of in studying the various species of Senrno-
pithed. Some of the species of this tailed group appear only to be distinguishable
from each other by differences of colour, some of them being deep black
others bright red. The dark-coloured species have their young bom yellow
or red.
The leading features,of the skull of S . hoolock as compared with JET. Icvr are its
less prominent orbital ridges, longer muzzle, more elongated nasal orifice, and
considerably larger teeth, associated with a much longer palate than in IT. lar.
Such a series of structural characters occurring in the skull along with peripheral
distinctions by which alone i t is possible to separate S . hoolock from S . lar clearly
indicate the two as distinct species.
On the other hand, the skull of Jff. agilis has the prominent ridges surrounding
the orbits, the short snout and palate and small teeth of S . Icvr, to which in
external characters it is closely allied. The skulls also of S . leuciscus and of
S . miilleri do not appear to me to present any very marked structural modification
on the skull of H. Icvr.
There is occasionally considerable asymmetry between the two sides of the facial
bones of S . hoolock, due to a lateral twisting which I have generally observed to he
towards the right side. I t is quite apparent in life, and sometimes produces a
most ludicrous appearance. This asymmetry does not appear to affect the rest of
the skull.
The canine teeth, unlike those of the higher anthropoid apes, appear to be
equally well developed in both sexes of all the species, if the specimens on which
these observations are founded have been correctly sexed, which I have no reason to
doubt, as I have as far as possible personally verified the sex in each instance.
Dahlbom, in his comparatively recent revision of the genus, has placed, it
appears to me, undue stress on the character of the absence or presence of a tubercle
on the clavicle, for the existence of such a nodule can hardly be regarded in the
light of a structural character, as it simply indicates th a t the muscle has had a
more powerful attachment to the bone than in those cases in which the nodule is
only feebly developed. Such a character would be largely influenced by the life
the animal led, and unless all the individuals on which his observation rests were
thoroughly ferine, its value is much lessened. Dahlbom accepts H . agilis as distinct
from S . rafflesii, and JEE. entelloides as separable from JEL. Icvr.
I append a synopsis of the species after a careful comparison and study of
the various types in Europe and the exainination of a very extensive series in
India.
H y l o b a t e s l a r , L i n n .
Le grand Gibbon, Buffon, Hist. Nat. vol. xiv. 1766, pi. ii. ; Ibid, Daubenton, p. 96.
Le petit Gibbon, Buffon, Hist. Nat. vol. xiv. 1766, pi. iii. ; Daubenton, p. 102; Latr. Hist. Nat.
Buffon (Sonnini ed.), vol. xxxv. 1809, p. 206, pi. ix.
The Long-armed Ape, Pennant, Syn. Mamm. 1771, p. 99; Hist. Quad, vol, i. (3rd ed.) 1798, p. 184
(in part) ; Shaw, Gen. Zool. vol. i. pt. i. 1800, p. 12, pi. v.
The Lesser Long-armed Ape, Penn'ant, Syn. Mamm. 1771, p. 100.
Le Gibbon, Hist. Nat. des Singes, 1797, l re fam. sect. ii. pi. i. ; Latr. Hist. Nat. de Buffon (Sonnini
ed.), vol. xxxv. (1809) p. 197, pi. viii.
Homo lar, Linn. Mantissa Plant. 1771, Append, p. 521.
Simia longimana, Scbreber, Säugeth. vol. i. 1775, p. 66, pi. iii. figs. 1 & 2 (Buffon) ; Erxleben, Syst.
Reg. An. 177, p. 9; Zimm. Geograph. Gesch. vol. ii. 1780, p. 1-74.
Simia lar, Boddaert, Elench. An. 1785, p. 55; Gmelin, Linn. Syst. Nat. (18th ed.) 1788, p. 29;
Fischer, Syn. Mamm. 1829, p. 12 (in part).
Pithecus lar, Latr. Hist. Nat. de Buffon (Sonnini ed.), vol. xxxvi. 1809, p. 276.
Pithecus varius, Latr. Hist. Nat. Buffon (Sonnini ed.), vol. xxxvi. 1809, p. 276.
Pithecus variegatus, Geoff. St.-Hil. Ann. du Mus. voL xix. 1812, p. 88.
Hybolates lar, Hliger, Abhand, der Akad. der Wiss. Berlin, 1815, p. 88 ; Kuhl, Beitr. zur Zool. 1820,
p. 5 ; Desmarest, Mamm. 1820, p. 50; pi. 5. fig. 8 (Buffon) ;/Wagner, Schreber, Säugeth. Suppl.
vol. i. 1840, p. 71, vol. v. 1855, p. 15; Lesson, Sp. des Mammif. (Mastol. Méth.) 1840, p. 52 ;
Martin, Hist. Quad, or Monkeys, 1841, pp. 416,417, 488 (plate) ; Blyth, Journ. As. Soc. vol. x.
1841, p. 888; vol. xii. 1848, p. 176; vol. xiv. 1845, p. 468; vol. xv. 1846, p. 172; vol. xvi.
1847, pp. 729, 780 ; vol. xliv. 1875, ex. no. p. 1; Cat. Mamm. As. Soc. Mus. 1863, p. 5;
Gray, Hand-list Mamm. B. M. 1843, p. 2 ; Cat. Monkeys and Lemurs, B. M. 1870, p. 10.
Cantor, Journ. As. Soc. Beng. vol. xv. 1846, p. 172 ; Fry, Proc. Zool. Soc. 1846, p. 15 * Ann,
& Mag. Nat. Hist. vol. xvii. 1846, p. 487 ; Is. Geoff. St.-Hil. Cat. Méthod. des Mammif. 1851,
p. 8; Gervais, Hist. Nat. des Mammif. 1854, p. 52 (fig. of head); Dahlbom, Stud. Zool. Fam.
Reg. Anim. 1856, pp. 78, 77 ; Tickell, Journ. As. Soc. Beng. vol. xxviii. 1859, p. 428 ; Ann,
and Mag. Nat. Hist. vol. xiv. 1869, p. 860-; Sclater, Proc. Zool. Soc. 1860, p. 86, pi. v.
Hylobates variegatus, Kuhl, Beitr. zur Zool. 1820, p. 5 ; Desmarest, Mamm. 1820, p. 51 ; Lesson,
Man. de Mamm. 1827, p. 81 ; Griffith, An. King. vol. v. 1827, p. 6 ; Bory de St. Vincent,
Diet. Class. d'Hist. Nat. vol. xii. 1827, p. 285 ; Is. Geoff. St.-Hil. Zool. Voy. de Bélanger,
1884, p. 27 ; Waterhouse, Cat. Mamm. Mus. Zool. Soc. 1888, 2nd ed. p. 4; Schinz, Syn.
Mamm. vol. i. 1844, p. 80 (in part).
Simia albimana, Vigors & Horsfield, Zool. Journ. no. 18, 1828, vol. iv. p. 107.
Simia variegatus, Fischer, Syn. Mamm. 1829, p. 11.
Hylobates albimanus, Is. Geoff. St.-Hil. Zool. du Voyage de Bélanger, 1884, p. 29 ; Schinz, Syn.
Mamm. vol. i. 1844, p. 28 ; Schlegel, Essai sur la Physion. des S.erpens, Pt. Gén. 1887, p. 237.
Hylobates leuciscus, Cantor, Ann. & Mag. Nat. Hist. vol. xvii. 1846, p. 838.
Pale Variety.
Hylobates entelloides, Is. Geoff. St.-Hil. Compt. Rend. vol. xv. 1842, p. 717; Zool. Voy. de Jacque-
mont, vol. iv. 1844, p. 13; Archiv. du Mus. vol. ii. 184—? p. 582, pi. xxix.; Cat. Method, des
Mammif. 1851, p. 9; Gervais, Hist. Nat. des Mammif. 1854, p. 52 (fig. of head); Dahlbom, Stud.
Zool. Fam. Reg. An. 1856, pp. 78, 76; Blyth, Journ. As. Soc. Beng. vol. xliv. 1875, ex. no. p. 2.
This species is generally easily recognisable by its pale yellowish, almost white,
hands and feet, by the grey, almost white, supercilium, whiskers, and beard, and by
the deep black of the rest of the pelage.