Simia capucina, Linn., Syst. Nat., i., p. 42 (1766).
Cebus capucinus, Geoffr., Ann. Mus., xix., p. 111 (1812); Gray, Cat. Monkeys Brit. Mus., p. 49 (1870); Schl., Mus. Pays Bas, vii., p. 19 (1876).
Cebus nigrovittatus, Wagner, Acad. Münch., v., p. 430 (1847, ex Natt. MSS.).
Cebus olivaceus, Schomb., Reis. Brit. Guiana, ii., p. 246, et iii., p. 770 (1848).
Cebus castaneus, Is. Geoffr., Cat. Méth. Primates, p. 46 (1851).
Cebus versicolor, Pucher., Rev. et Mag. Zool., 1857, p. 346 (part).
Characters.—Hairs of crown short, reflexed, but not elevated into a crest. Fur brown, washed with yellow; crown-spot dark brown, narrow, prolonged down the nose, and expanded backward on to the nape of the neck; sides of face, throat, chest, and front part of shoulders, greyish-yellow.
Distribution.—Widely distributed in the great forests from Paraguay to the United States of Colombia.
Habits.—This Capuchin wanders about among the high forest trees in small companies of from ten to a dozen, the larger number being females. It is very timid, and keeps well out of sight, so that it is difficult to watch its habits. Rengger, in his "Säugethiere von Paraguay," had more than once an excellent opportunity of observing these interesting Monkeys, and has given a capital account of them. He specially mentions the great affection the mother has for her offspring. "The mother's love," he says, "shows itself by the great care with which every old one handles her young, by laying them on the breast, by watching them, by searching their fur, and by the attacks they make on any intruder." In January the female gives birth to a single young one, and keeps it at her breast for the first week; later on she carries it partly on her back, partly under her arm. When sleeping the Weeping Çai curls itself up, covering its face with its arms and tail.
The leader of a troop shares his feelings with the others by various motions, and by giving utterance to certain noises, which are taken up by the others. Their feelings are also exhibited by a kind of laughing and crying. Rengger kept some of these Monkeys for several years in captivity in their own country, and says that, when happy, they uttered a peculiar tittering sound; they express agreeable sensations by drawing back the corners of the mouth without uttering any sound; this he supposed to be laughing, but, as Mr. Darwin remarks, it would be more appropriately called a smile. When crying, their eyes fill with tears, but never flow down the cheeks. When in pain or terror, the form of the mouth, as observed by Mr. Darwin at the Zoological Gardens in London, is quite different from that expressing pleasure or satisfaction; and high shrieks are uttered.