DISTRIBUTION.--Confined, so far as at present known, to the forests traversed by the Rio Casiquiare, Rio Negro, and Rio Branco. This is the most northern form of the three species of the genus, and apparently the most widespread also (see map, p. 180). This is doubtless the "black-faced, grey-haired" species, neither white nor red, which Mr. Bates was {176}assured took the place of _B. calvus_, at 180 miles northward from the mouth of the Japurá. HABITS.--Living in the high trees of the forest, feeding on fruits; and not differing in habits from those of the other species of the genus, which are referred to below. II. THE RED UAKARÍ. BRACHYURUS RUBICUNDUS. _Brachyurus rubicundus_, Is. Geoffr. and Dev., C. R., xxvii., p. 498 (1848); Is. Geoffr., Arch. Mus., v., p. 564, pl. 30 (1845); Castelnau, Expéd. Amér. Sud, Mamm., p. 19, pl. 4, fig. 2 (1855); W. A. Forbes, P. Z. S., 1880, p. 646, pls. lxi., lxii. _Ouakaria rubicunda_, Gray, Cat. Monkeys Brit. Mus., p. 62 (1870). _Pithecia rubicunda_, Schleg., Mus. Pays Bas, vii., p. 228 (1876). CHARACTERS.--Face, chin, lips, forehead, and sides of face, bare (except for a few superciliary hairs, and scant representatives of moustache and beard), all bright vermilion red, deepening with emotion. Eyes brown; ears square in shape, without a lobule; hair on top of head short, silky, and grey; that on the side of the lower jaw and throat long and rich chestnut-red, running forward as far as the symphysis, and forming whiskers. Hair of upper surface of body entirely rich chestnut-red, more or less black-tipped and long, especially on the shoulders and limbs; hair of head, nape, and neck paler than on the rest of the body; tail, haired below at tip, rich chestnut-red; under surface of body rich chestnut-red, and less hairy. The fur in general colour and texture resembles that of the Orang, the red hair, continued on to the limbs and tail, being particularly long on the arms and shoulders (forming a sort of cape), and {177}along the hind border of the thigh and leg. (_W. A. Forbes_). Between the thigh and the lower part of the leg there is a wide expansion of the skin behind the knee. The thumb is in the same plane with the other digits and not opposable; digits with compressed and rather elongated nails; the nail of the thumb and the great-toe shorter and more "nail"-like; upper surface of the hands and feet haired, on to the fingers. The cæcum (6 inches) and intestines (22 inches) are absolutely and relatively longer than in any other New World Monkey. Length of the body, 27-28 inches; of the tail, 6½