This rare and pretty little animal has been compared, and not unaptly, to a diminutive black Dog with a white face. Its whole colour, in fact, is of a uniform shining blackness, with the exception of the face, neck, and arms, which are dull white, the former being surrounded with a narrow band of pure white. This remarkable disposition of colour has obtained for it, from the Creoles, the fanciful name of Widow Monkey, the whiteness of the face, neck, and arms being compared to the veil, handkerchief, and gloves worn in its native country by widows. It is described as particularly gentle and timid, except when a small bird--its natural food--is placed in its sight; it then becomes animated and eager, darts at it like a Rat, and devours it in an instant; at other times it will remain motionless for hours, attentively watching whatever is going on. It seems, however, to have a particular aversion to its hands being touched, since they are immediately withdrawn, and hid under its belly. It evinces a great dread of other Monkeys, but not those of its own species. Of its native history we are entirely ignorant. The usual length of the body is not more than one foot. The head is round, the muzzle short, and the general expression of its physiognomy is agreeable. The colours we have already noticed. The nose is short and flat, and the ears are almost naked. The hands are nearly white on the outside, but black within, and the hinder hands, or more properly feet, are entirely black; the tail is also black, and a little longer than the body. Very probably this pretty Monkey is only a variety of Callithrix amictus, which has a blackish-brown fur, with the under half of its throat white, and the hands are of a dull yellow or whitish colour. THE ONAPPO.[96] This Monkey belongs to the same division of the genus as the Widow Monkey, and it is interesting because its habits are nocturnal. It feeds and roams by night instead of by day. Doubtless many other kinds do so, but it has been recorded of this species from its first discovery. They live in Para, and in the Brazils, and are remarkable for the agile and graceful way in which they jump from tree to tree, the females carrying the little ones on their backs, and moving with the vivacity and restlessness of birds. Resting during the day, they roll themselves up like balls, and utter plaintive, deep-seated, weary cries, which have given them the name of Ventriloquist Monkeys. At night they are all life and movement, and then they search for insects and eggs, and enjoy themselves. Their colour is a reddish-grey, and spotted on the upper parts of the body, and beneath and on the limbs the tint is of a vivid maroon. The tail is grey, tipped with white. There are fourteen species of the genus, and they range to the southern limits of the great forests. [Illustration: CALLITHRIX AMICTUS.] GENUS NYCTIPITHECUS--THE DOUROUCOULIS--THE OWL MONKEYS.