CHARACTERS.--Very similar to _A. ater_ in its coarse and entirely black fur, but differing in the naked and flesh-coloured {238}face. Hairs of forehead long and projecting anteriorly; tail one-quarter longer than the body; hands generally entirely lacking the thumbs, though sometimes a rudimentary thumb is present, and that occasionally on one hand only. Naked portion of tail covered with sensory papillæ, rendering it more sensitive, so it is said, than the hand. Length of body, 24 inches; tail, 30 inches. The skull in some specimens of the thumbed variety is compressed laterally, and shows a sagittal crest along the top. DISTRIBUTION.--This species is spread over Guiana, the forests of the Ucayali and Huallaga rivers in eastern Peru, and the northern part of Brazil, where it is known as the "Coaita," taking the place of the more northern _Ateles ater_. "It occurs," says Mr. Bates, "throughout the lowlands of the Lower and Upper Amazons, but does not range to the south beyond the limits of the river plains." In the higher part of the Rio Negro it comes down to the north bank, but does not cross to the south bank of the river. HABITS.--This species is the best known of all the Spider-Monkeys. It is captured in large numbers, when young, by the natives of Guiana, and as they bear captivity well, many of them have been brought to Europe. They live in larger troops than do some of the other members of its genus; indeed, these companies are said to number as many as a hundred. They are very easily tamed, and become very affectionate. They live chiefly on fruits, principally on a species of palm-nut. Dampier, however, says, apparently of this species of _Ateles_: "The Monkeys come down by the Sea-side [at low water] and catch them [the Periwinckles and Muscles]; digging them out of their Shells with their Claws." Large numbers of this species {239}are also annually killed for food, their flesh being held in high esteem by the natives. V. THE WHITE-WHISKERED SPIDER-MONKEY. ATELES MARGINATUS. _Ateles marginatus_ (nec Humb.), Geoffr., Ann. Mus., xiii., p. 92, pl. 10 (1809); Kuhl, Beitr. Zool., p. 24 (1820); Gray, Cat. Monkeys Brit. Mus., p. 43 (1870); Schl., Mus. Pays Bas, vii., p. 174 (1876). _Coaita à front blanc, femelle_, Fr. Cuv., Hist. Nat. Mamm., livr. lxii. (Avril, 1830). _Ateles frontalis_, Bennett, P. Z. S., 1831, p. 38. CHARACTERS.--Similar in size and coloration to _A. paniscus_. Body lean; hair moderately long and coarse. Face naked, black, except the skin round the eyes, which is flesh-coloured; general colour black; under surface of body and inner sides of limbs, ashy-grey. It differs from _A. paniscus_ by having the forehead, crown of head, a spot on each side of the nose, and the whiskers, white. A specimen in the British Museum has four pre-molars in each upper jaw, instead of the normal three of the _Cebidæ_.