Seated among the boughs may often be seen, in the forests of the Upper Amazon, a number of large, stout-bodied, fat-paunched monkeys, with long flexible tails, furnished underneath with a naked palm, like the hand, for grasping. Their faces are black and wrinkled, their foreheads low, and eyebrows projecting; their features bearing a wonderful resemblance to those of weather-beaten old negroes. The heads of some are covered with black hair, and others with grey. They are called by the Portuguese _macacos barrigudos_, or big-bellied monkeys. They belong to the species of Lagothrix, and are closely allied to the coaitas. They are bulky fellows, and though able, by means of their prehensile tails, to get along at a good rate among the boughs, seldom trouble themselves to move rapidly. With the exception of the black howler, which will be described anon, they are the largest monkeys in America--their bodies measuring about twenty-eight inches in height. Their flesh being highly esteemed by the natives, they are unceasingly hunted by the Indians. Though their manners are somewhat grave, yet, from their mild and confiding temper similar to that of the coaitas--they are much sought after for pets. They live exclusively on fruits. THE UAKARI. On the western side of the River Yapura, near where it pours its waters into the Amazon--a forest region inundated during the greater part of the year--there lives in small troops, high up among the crowns of the lofty trees,--where it feeds on fruits of various descriptions,--a small, almost tailless monkey, its face glowing with the most vivid scarlet hue. Its body, about eighteen inches in height, exclusive of limbs, is clothed from head to tail with very long, straight, shining, whitish hair. Its head, nearly bald, is sprinkled over with a short crop of thin grey hair; whilst round its ruddy countenance, bushy whiskers, of a sandy colour, meet under the chin. It has reddish-yellow eyes. It belongs to the Cebidae family. The Indians call it the white uakari. It inhabits, as far as is known, no other district. In spite of its want of tail, it is an active little creature, running up and down the larger branches, but seldom leaping from one to the other. The mothers, as is the custom with the other monkey orders, carry their young on their back. They are highly valued as pets; but being of a delicate constitution, seldom live long when transported from their native district.