These curious little Monkeys are found in nearly all parts of South America, and they live in troops, making their homes in trees. They feed on the insects which are usually found in great quantities in many of the South American trees, and occasionally they will descend to the ground, in search of small Fish and Molluscs which they find in the mud on the banks of the rivers. It is said that they even venture on the beds of the rivers when the water is low, and capture the oysters, and they are very quick in learning how to open the shells and take out the oyster.
These Monkeys are distinguished by their fine silky hair, their strong tails, which they use in climbing and in swinging themselves from limb to limb, and the fact that they have no thumbs; but only the four fingers on each hand. This peculiarity has given them the Greek name by which the family is usually classified which means imperfect, but the name Spider Monkey has been given to them because of their long, slender limbs and their slow, queer manner of walking, which sometimes gives them the appearance of huge spiders.
The Weeping Monkeys are smaller, but not so slim as the Spider Monkeys. They live in the forests of Guinea and Brazil, and flock together in great troops. They will eat snails and small Birds when they can get them, but their principal food is the abundance of fruits found among the trees where they make their home.
They generally keep on the topmost branches of the highest trees to keep out of the way of the Serpents, of which they are very much afraid. Even when tamed and brought to this country, the sight of the most harmless Snake will fill them with terror.
These Monkeys are called weepers from their plaintive cry. Usually their voice is soft; when excited or angry it becomes loud and pitiful; when teased it keeps up a kind of plaintive wailing, which has given it its name of Weeping Monkey, although they have also been called Musk Monkeys at times, because of their musky odor.
These Monkeys have short round heads with the skull projecting backwards, and many of them have their faces bordered with long hair; others have long hair on top of the head, and in one species, called the Horned Monkey, this hair forms two black tufts, having the appearance of horns.