| Class.—Mammalia. | ||
| Order.—Primates. | ||
| Family.—Catarrhini. | ||
| Sub-Family. — |  | 1. Anthropomorpha. |
| 2. Cynomorpha. | ||
| 1. Anthropomorpha. | |||
| Genus — | Troglodytes. | Example — | The Gorilla and Chimpanzee. |
| „ | Simia. | „ | The Orang-utan. |
| „ | Hylobates. | „ | The Gibbons.[72] |
| 2. Cynomorpha. | |||
| Genus — | Semnopithecus. | Example — | The Entellus Monkey. |
| „ | Colobos.[73] | „ | The Guereza. |
| „ | Cercopithecus. | „ | The Guenons and Mangabeys.[74] |
| „ | Macacus. | „ | The Magot. |
| „ | Cynocephalus. | „ | The Baboons.[75] |
CHAPTER X.
THE MONKEYS OF THE NEW WORLD.[76]
THE CEBIDÆ—THE HOWLERS—THE WOOLLY MONKEYS—THE SPIDER MONKEYS—THE SAJOUS.
The Monkeys of the New World—How Distinguished from those of the Old—Their Division into Families—The First Family, [THE CEBIDÆ], with Prehensile Tails—[THE HOWLERS]—Appropriateness of their Name—Where Found—General Description—[THE YELLOW-TAILED HOWLER]—Anatomical Peculiarities and Appearance of the Face—Other Members of the Family—[THE BLACK HOWLER]—Its Locality—[THE WOOLLY MONKEYS]—[THE CAPARRO AND BARRIGUDO]—First noticed by Humboldt—Peculiarities of the Skeleton—[THE SPIDER MONKEYS]—Seen by Humboldt in the Brazilian Forests—Remarkable Power of the Tail—Flexibility of the Limbs—Conformation of the Brain—Other Species—[THE COAITA]—Curious Stories of them in Captivity—[THE CHAMECK]—[THE BLACK SPIDER MONKEY]—Its Geographical Range—Its Position in Sleep—[THE VARIEGATED SPIDER MONKEY]—[THE SAJOUS]—[THE CAIARÁRA]—Observed by Bates on the Amazon—Other Varieties—[THE BROWN SAJOU]—[THE CAPUCHIN SAJOU]—Described by Brehm—Their Remarkable Dexterity and Cleverness—Diseases of Monkeys
NOT one of the numerous kinds of Monkeys which have been noticed in the former chapters has ever been found in the New World—that is to say, on the American continent. The converse is also true, for not one of those which are about to be noticed, and which inhabit the tropical parts of South and Central America, has been seen in any other part of the world.
The two groups are not only distinct as regards their geographical distribution, but they are also different in many very important points of their construction and habits. It is evident that, although it may be said that the resemblances between the Baboons, Macaques, and Troglodytes, for instance, indicate some kind of relationship, and suggest a community of origin, there is nothing of the sort to be traced between any Old and New World Monkeys. They seem to have started from different sources.
All the Monkeys of the New World have the partition between the nostrils broad, and it separates them widely: they open as it were sideways, and the whole of the lower part of the nose is flat. This peculiarity has given the name to the group, as has been explained in the first chapter, and it is accompanied by some others. Thus, with one exception, the numerous genera of the New World Monkeys have the hinder limbs the longest, and they are wont to go on all-fours, the erect posture being only occasionally adopted by the Spider Monkeys. Their thumbs differ less from the other fingers than do those of the Old World Monkeys, and the toe-thumb is large and movable; no cheek-pouches or callosities are seen in any of them, and only a few have air sacs. It is usual to say that the American Monkeys are known by their prehensile tails, but this is only true in part, for whilst some have this member wonderfully developed and useful, others have it incapable of holding on, whilst a few have barely a tail at all. The teeth are more numerous than in the Apes and Monkeys of the Old World, in one set of New World genera; and they are of the same number in another. In the first instance, there are thirty-six teeth instead of the thirty-two so frequently noticed hitherto, and in the last the thirty-two are differently arranged to those possessed by the Old World kinds. For example, in the prehensile-tailed Howlers, there are thirty-six teeth, or one extra tooth in each jaw and on both sides, over and above the usual thirty-two; and this tooth is a false molar, or one of those between the true grinders and the canine teeth. There are thus three false molars instead of two, as in the Old World kinds, on each side in both jaws.
In the Marmosets, which have only thirty-two teeth, there are only two back grinders in each jaw on each side instead of three, as in the Old World Monkeys, but there are three pre-molars in each jaw on each side. All these distinctions are useful in the classification of these American Monkeys, and therefore they have been divided into two families, one having thirty-six and the other thirty-two teeth, and the first family has again been subdivided into the genera with prehensile tails and those without them. The first to be described are the Cebidæ, and this family contains—first, the genera with thirty-six teeth and with prehensile tails; second, the genera without prehensile tails and the same number of teeth.