HABITS.--This Monkey, the "Chuva de Baracamorros" of {233}Humboldt, which is the most beautifully coloured of its group, is said to go about in small parties, passing through the forest at a rapid rate, feeding on different kinds of berries. II. GEOFFROY'S SPIDER-MONKEY, ATELES GEOFFROYI. _Ateles geoffroyi_, Kuhl, Beitr. Zool., p. 26 (1820); Schl., Mus. Pays Bas, vii., p. 181 (1876); Alston, in Godman and Salvin, Biol. Centr. Amer. Mamm., p. 8 (1879). _Ateles melanochir_, Desmar., Mamm., p. 76 (1820); Gray, Cat. Monkeys Brit. Mus., p. 43 (1870); Sclater, P. Z. S., 1871, p. 226, pl. xv., 1875, p. 419, pls. xlviii. and xlix. _Eriodes frontatus_, Gray, Ann. Nat. Hist., x., p. 256 (1842); id. Voy. H.M.S. "Sulphur," Zool., p. 9, pl. i.; Scl., P. Z. S., 1882, p. 186; Von Frantzius, Arch. f. Naturg., xxxv., 1869, pp. 257, 258. _Sapajou geoffroyi_, Slack, Pr. Ac. Sc. Philad., 1862, p. 511 (= female). _Ateles variegatus_ (nec Wagn.), Von Frantzius, Arch. f. Naturg., xxxv., 1869, p. 257. _Ateles hybridus_, _A. ornatus_ et _A. albifrons_, Gray, Cat. Monkeys Brit. Mus., pp. 43 and 44 (1870). CHARACTERS.--Body light greyish-drab all over; hands, elbows, feet, knees, and the upper side of the extremity of the tail, black; face black, with the exception of the lips and a ring round the eyes, broad above and narrow below, flesh-coloured. Hair of forehead reflexed, meeting that of the crown above the eyes, forming a triangular patch of erect black hairs. Top of the head and upper part of the tail buff. Length of body, 17 inches; of tail, 21 inches. Thumb entirely wanting. This species is remarkably variable. The description given above belongs to the form described as _A. melanochir_ by {234}Desmarest from the same specimen in Paris, which Kuhl described under the name of _A. geoffroyi_. Every gradation is to be met with between this and the form described by Dr. Gray as _A. ornatus_, in which the face is entirely black, the whiskers pale reddish-yellow, the patch of erect black hair on the forehead yellowish at its base; the top of the head, sides, lower back, rump, upper part of the arms, outer, inner and posterior portion of the thighs and legs, and under side of the base of the tail, brownish-red; nape, shoulders and remainder of the tail reddish-brown, washed with black; lower part of arms, fore-arms, hands, feet, and anterior aspect of thighs and legs, black. In some specimens the grey, or reddish-black colour, merges on the under surface, into yellowish-cream, or rufous, and the black wash is more or less distributed. Mr. Alston, in speaking of this species, remarks that the best character by which the darker (_A. ornatus_) forms may be distinguished from our next species (_A. rufiventris_) is the want of a distinct line of demarcation between the colours of the upper and lower parts, the tint of the flanks, whatever it may be, passing almost insensibly into that of the breast and belly in all the varieties.