Nyctipithecus felinus, Spix, Sim. et Vespert. Bras., p. 24, pl. 18 (1823); Is. Geoffr., Cat. Méth. Primates, p. 39 (1851); Gray, Ann. N. H., x., p. 256 (1842).
Nyctipithecus oseryi, Is. Geoffr. et Deville, C. R., xxvii., 1848, p. 498 (juv.); Geoffr., Cat. Méth. Primates, p. 39 (1851).
Nyctipithecus commersonii, Gray, Cat. Monkeys Brit. Mus., p. 58 (1870).
Nyctipithecus vociferans, Schl., Mus. Pays Bas, vii., p. 214 (1876; part).
Characters.—Closely related to the last species, but differs in having the three facial streaks irregular and combining together on the crown, the middle one broad and lozenge-shaped; the frontal spots short, and white. Fur longer and more woolly; neck, chest, under surface of body, inner sides of the limbs, and the base of the tail yellowish; tail round.
PLATE XV.
THE RED FOOTED NIGHT-MONKEY.
Distribution.—This species is rather rare, but it has been obtained at Ega and at Tabatinga on the Upper Amazons; on the Ucayali, and near Yurimaguas on the Huallaga River—in the warm and humid virgin forests—in fact, generally along the Peruvian Amazons.
In speaking of his collections made at Ega on the Upper Amazons, which he describes as a fine field for a Natural History collector, Mr. Bates gives an interesting account of the Night-Apes, called "Ei-á" by the Indians, observed by him during his various journeys. "Of these I found two species (Nyctipithecus trivirgatus and N. felinus) closely related to each other, but nevertheless quite distinct, as both inhabit the same forests, namely, those of the higher and drier lands, without mingling with each other or inter-crossing. They sleep all day long in hollow trees, and come forth to prey on insects and eat fruits only in the night. One cannot help being struck by this curious modification of the American type of Monkeys, for the Owl-faced Night-Apes have evidently sprung from the same stock as the rest of the Cebidæ, as they do not differ much in all essential points from the Whaiapu-Sais (Callithrix) and the Sai-miris (Chrysothrix). They have nails of the ordinary form on all their fingers, and semi-opposable thumbs; but the molar teeth (contrary to what is usual in the Cebidæ) are studded with sharp points, showing that their nocturnal food is principally insects.