Page:EB1911 - Volume 22.djvu/345

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331
PRIMATES

the long hair fringing the face and meeting under the chin, and the tufted lion-like tail, which is from one-half to three-quarters the length of the body. The last group (Cynomalgus), now often regarded as a distinct genus, is typified by the widely-spread crab eating macaque (Ill. cynomolgus), characterized by its produced muzzle, short and stout limbs, and basally-swollen tail, which is nearly as long as the body. It also includes the South Indian bonnet-macaque (M. sinicus) and the Ceylon toque-macaque (ll. pileatus), taking their names from the elongated hair on the crown, which are nearly allied, and with the first-named species approach the baboons in their elongated muzzles (see MACAQUE).

A still nearer approach to the baboons is made by the black ape (Cynapithecus niger) of Celebes and the neighbouring islands, which is represented several sub-species, among them the so-called


FIG. II.-The Yellow Baboon (Papio cynocephalus).

Moor-macaque (Macacus maurus). Some difference of opinion exists as to the proper serial position of this species, which is included in Macacus by several zoologists who separate Cynomolgus as a genus. It is characterized by the marked elongation of the muzzle, which, like the neck, hands and feet, is naked. The nostrils are, however, directed outwards and downwards, as in the macaques; but, on the other hand, there are baboon-like ridges on the sides of the muzzle and heavy supra-orbital ridges. There are large cheek-pouches; and the tail is a mere stump. The colour is sooty-black. The weird-looking gelada baboon (Theropithecus gelada) of southern, and the allied T. obscurus of eastern Abyssinia represent a genus which is essentially baboon-like in general characteristics, but has the nostrils of the macaque-type, while the facial portion of the skull is shorter than the cranial. The preorbital portion of the face is concave with the ridges rounded, and the tusks are very long. The long tail is tufted at the tip, and the hair is long and bush, developing into a mantle-like mane on the forequarters of old) males, leaving the chest bare. The eneral colour is dark-brown. The last representatives of the Circzyithecidae are the baboons, or dog-faced baboons, of Africa an Arabia, forming the genus Papio. These are for the most part large monkeys, associating in herds under the leadership of an old male, and dwelling chiefly among rocks, although they ascend trees in search of gum. They are easily recognized by their long dog-like faces (fig. II), in which the nostrils open at the extremity of the greatly elongated muzzle. On the sides of the muzzle are prominent longitudinal ridges covered with bare skin which may be brilliantly coloured. The callosities, which are also generally bright-colouredil are large; and the tail is of moderate length or short. The hairs are ringed with different colours, and the general colour is olive yellow, grey or brownish. The typical, and at the same time the smallest representative. of the group, is the yellow baboon (P. cynocephalus or P. babuin) (fig. II), ranging from Abyssinia to Angola and Mozambique, and distinguished by its rather short and grooved muzzle and longish tail, which is nearly as long as the body. The majority of the species, such as the widely spread P. anubis (with several local races), P. .Sphinx of West Africa, and the chacma (P. porcarius) of South Africa, are included in the sub-genus Chaeropithecus, and have the muzzle longer and undivided and the tail shorter, in most the colour is golden-olive with very distinct rings, but in the chacma it is darker. The hamadryad baboon, P. hamadfyas, of north-east Africa and Arabia, and the closely allied P. arabicus of southern Arabia, represent a sub-genus (Hamadryas) characterized b the ashy-grey colour and the profuse mantle-like mane of the atliilt males; the tail being slightly shorter than the body. Lastly, the West African mandrill (P. maimon) and drill (P. Zeucophaeus) form the sub-genus Maimon, distinguished by the extremely short tail, and the great development of the facial ridges, which are strongly Huted. In the mandrill, which is the most brilliantly coloured of all mammals, the ridges are vermilion and cobalt, while the callosities on the buttocks are of equal brilliance; but in the drill, which has white ear-tufts, the colouring is more sombre (see BABOON and MANDRILL).

American Monkeys and Marmosets.~The monkeys and marmosets of tropical America constitute the Platyrrhina, or second section of the Anthropoidea, and are characterized as follows: An additional premolar is present in both jaws, bringing up the number of these teeth to three pairs. The tympanum is ring-like, with no external bony-tube, or meatus; and a tympanic bulla exists. A parieto-zygomatic suture causes the jugal bone to be included in the orbital plate; and the orbito-temporal foramen is large. Cheek-pouches and callosities on the buttocks are wanting. The descending colon does not form a sigmoid flexure; and the caecum is generally bent in a hook-like form, with, at most, very slight narrowing of its terminal extremity. The cartilage forming the inter-nasal septum is broad, and the nostrils are directed obliquely outwards. The tail, which never has fewer than fourteen vertebrae, is generally as long as the body, and frequently prehensile. The ethmoturbinals are originally separate; and the laryngeal sac, when present, is of peculiar type. Usually there is only a simple primary discoid placenta, but rudiments of a secondary one have been recently described.

The first family, or Cebidae, includes the American monkeys, as distinct from marmosets, which present the following characteristics: The ears are more or less naked externally. The terminal joints of the fingers and toes carry flat or curved nails; and the thumb, when present, is opposable to the other fingers. Except in the uakaris, the tail is long, generally short-haired, and frequently with a terminal bare surface for pretension. Dentition i. § , c. }, p. § , m, 3. Generally a foramen (entepicondylar) in the inner side of the lower end of, the humerus. As a rule, only a single offspring is produced at a birth. Ranging over tropical America, the Cebidae have their headquarters in the vast Brazilian forests, where so many of the animals are more or less arboreal in their habits. These monkeys are completely arboreal, more so, indeed, than the gibbons among the Catarrhina.

The first sub-famil, Alouatinae, is re resented only by the howlers, Alouata (or Iliycetes), characterized) by the long prehensile tail with the extremity naked below, the well-develo d thumb, and the extension of the hyoid-bone into an enormous lilfadder-like chamber contained between the two branches of the lower jaw (fig. 3). In this bony cu is received one of the three or five laryngeal Sacs. There are about half a dozen species, with several sub-species; three of the best known being A. seniculus, A. belzebul and A. ursina.. Several are brilliantly coloured, with bright or golden hair on the flanks; but in the Amazonian A. nigra the male is black and the female straw-coloured. The muzzle is longer than in other Cebidae (see HOWLER).

FIG. 12.-The White-cheeked Capuchin (Cebus lunatus). The Cebinae include the typical members of the family, characterized by the large brain, of which the elongated hemispheres cover the cerebellum; the brain-case of the skull being, of course, elongated in proportion. The lumbar vertebrae are short, w1th upright comb-like processes, instead of the rhomboidal ones of the howlers, The lower 'aw and hyoid are of normal form. In the first section of the sub-family the tail is evenly haired throughout, the thumb