( Originally Published 1936 )
This sub-family, the last of the Quadrumana of the Old World, is easily distinguished by the long tail, the legs longer than the arms, and the absence or very slight development of cheek-pouches. We have figured representatives of three of the principal genera.
White-Tailed Guereza (Colobus caudatus)
There are nine species represented in this genus of African monkey, not differing greatly from each other except in colour, which may be black, blackand-white, or yellow. In all of them the thumb is totally lacking. They are tree-living in habits, feeding on fruits and vegetables, and are said not to be so destructive to plantations as many other monkeys. The back is covered with a long silky mantle of hair, which in the species figured is white, as are the tail and the ring of hair around the face, contrasting sharply with the black fur of the rest of the body. Plate 2, Fig. 9. This long shining hair is much ad-mired by the natives of the region in which the Guerezas live, and it is largely exported to other countries for manufacture into furs.
Hanuman Monkey (Semnopithecus entellus)
Many species of the genus Semnopithecus are found in the Oriental countries, being especially numerous in India and the adjacent islands. These are small, slender monkeys, covered with rather long glossy hair, in general greyish in colour. The hair grows in a very peculiar manner on the head, radiating from a point on the forehead and forming a cap, with stiff black edges projecting over the brows. The face, ears, hands and feet are black, and the thumb is short, but the big toe is greatly developed. One of the best known forms is the Hanuman, or Langur. See Plate 2, Fig. 6. These creatures are protected by the natives of India, who, believing that they em-body the souls of departed ancestors, allow them the utmost liberty, never on any account molesting them. So numerous did they become at one time, and such a nuisance because of their mischievous habits, that the English Government interfered, capturing and sending away from the country many hundreds of them.
Proboscis-Monkey (Nasalis larvatus)
This extraordinary-looking monkey is a native of Borneo, where it is found in the trees in small companies. It is reddish-brown in colour, with the sides of the head, the shoulders, and the limbs more or less inclining to yellow, the tail, which is very long, yellowish or white. But the most noticeable feature in its construction is the long nose, which is greatly developed in the adult male and gives it a most ludicrous appearanceŚmaking it seem a caricature of a human being. See Plate 2, Fig. 5. This monkey is very delicate, and seldom lives long in captivity. In the wild state it feeds on young leaves and shoots.
Capuchin Monkey (Cebus capucinus)
There are many species of the Capuchin Monkeys found throughout South America, living in small troops in the trees. They are of small size, not much more than a foot in length, and are variable in colour, the species here represented being yellowish-brown. The forehead is bare and wrinkled, and the hair on the head is not raised in a crest as it is in some of the other species of the genus Cebus. See Plate 4, Fig. 15. These Monkeys bear captivity well, are gentle in disposition and easily tamed, and are more often seen about the country with organ-grinders than any others of the tribe.
Red Howler (Alouatta senicula)
The Howling Monkeys are so called from their habit of uttering loud cries, or howls, which are made possible by a peculiar formation of the throat and tongue. There are several species, the two principal ones being the Red Howler and the Black Howler, the first of which is here figured. They are larger than the capuchins, more ungainly in form, and have longer muzzles, but like the others, they are tree-living, feeding on fruit and leaves, and have long prehensile tails, which are used as a fifth hand. The colour varies considerably in the different species. The Red Howler has long coarse red hair, paling to yellow, with a heavy beard about the face. See Plate 3, Fig. 12.