Page:EB1911 - Volume 22.djvu/344

Rh snub-nosed monkey, R. roxellanae (fig. 9), of eastern Tibet and Szechuen, is characterized by the curiously short and upturned nose and the long silky hair of the back, especially in the winter coat. In the typical species the predominating colour is orange, tending to yellowish-olive on the back; but in R. bieti of the mountains bordering the valley of the Mekon and R. brelichi of Central China it is slaty-grey. The third Asiatic genus is represented by the proboscis monkey (Nasalis larvatus) of Borneo, in which the nose is extraordinarily elongated. The nose of the adult male is commonly represented as projecting straight out from the face, but it really bends down to overhang the upper lip; it is much shorter in the female, and quite small and bent upwards in the young. (See and .)

The African guerezas, forming the genus Colobus, differ from their Asiatic cousins by the total loss of the thumb. Some of these monkeys, like Colobus satanas of West Africa, are wholly black; but in others, such as C. guereza (or abyssinicus), C. sharpei and C. caudatus of North-east and East Africa, forming the sub-genus Guereza, there is much long white hair, which in the species last named forms a mantle on the sides of the body and an elongated fringe to the tail, thus assimilating the appearance of the animal to tie long lichens hanging from the boughs of the trees in which it dwells. Most or all of the Semnopithecinae feed on leaves; a circumstance doubtless correlated with the complex structure of their stomach.

Cercopitheques, Mangabeys, Macaques and Baboons.-The whole of the remaining members of the family Cercopithecidae are included in the sub-family Cercopithecinae, which presents the following characteristics: The hind limbs are not longer than the front pair; the tail may be either long, short or practically absent; cheek-pouches are present; the stomach is simple; the callosities on the buttocks are often very large; the last lower molar may or may not have a posterior heel; and the thumb is well developed. Whereas all the Senmopithecinae are completely arboreal, many of the Cercopithecinae, and more especially the baboons, are to a great extent, or entirel terrestrial. The typical representatives of the group are the African monkeys, forming the genus Cercopithecus, which includes very large number of species with the following characters in common: the tail, although shorter than in the Semnopithecinae, is long, as are the hind limbs, while the general form is slender. The jaw and muzzle are short and the cheek-pouches large; while the nose is not prominent, with the nostrils approximated; whiskers and a beard of variable length are usually developed. The fingers of the long hands are united by webs at the base; the thumb is small in comparison with the great toe. The callosities are of moderate size; and the hairs of the thick and soft fur are in most cases marked by differently-coloured rings. For convenience of description the numerous species of this genus may be arranged in a number of groups or sub-genera. The first of these groups includes the spot-nosed forms (Rhinostictus), characterized by the presence of a spot of white, red or blue on the nose; well-known species,

being the lesser white-nosed guenon (C. petaurista) of West Africa and the hocheur, C. nictitans, which is also West African. In the typical group, as represented by the malbrouck monke (C. cynosurus) of the West Coast, and the Abyssinian grivet (C. sabaeus), the fur of the back is of a more or less olive-green hue, while the under surface and whiskers are white and the limbs grey. The large patas monkey (C. patas) of West Africa and the red-backed monkey (C. pyrrhonotus) of Kordofan typify a third section (Erythrocebus), characterized by the red upper and white lower surface of the body. A fourth section (Mona) includes the mona (C. mona) of Western, and Sykes's monkey (C. albigularis) of Eastern Africa, with a number of allied species, characterized by the presence of a black band running from the outer angle of the eye to the ear, and the black or dark-grey limbs. The bearded monkey (C. pogonias) of Fernando Po and Guinea, with two sub-species, typifies a small section (Otopithecus), characterized by large rufous or yellowish ear-tufts and the presence of three black stripes on the forehead. Pagonocebus is another small section, including the well-known Diana monkey (C. diana) of Western, and De Brazza's monkey (C. neglectus) of Eastern Africa, easily recognized by the long (generally white) beard and frontal crest. Finally, the little talapoin (C. talapoin) of the Gaboon alone represents a group (Miopithecus) broadly distinguished by having three, in place of four, cusps on the crowns of the lower molars.

The next group is that of the African mangabeys (Cercocebus), the more typical species of which are easily recognized by their bare flesh-coloured eyelids, and the absence of rings of different colours on the hair, or at least on that of the back. In these monkeys the general form is intermediate between that of the cercopitheques and the macaques, to be next mentioned, the head being more oval and the muzzle more produced than in the former, but less so than in the latter. The limbs are longer and the body is more slender than in the macaques, and the callosities are also smaller. On the other hand, the thumb is smaller than in the guenons, and the tail is carried curled over the back instead of straight; while these monkeys differ from the former in having a posterior heel to the last lower molar, which is thus five-cusped, as in the macaques. The laryngeal air sacs of the latter are, however, wanting. Well-known representatives of the typical section of the group are the sooty mangabey (C. fuliginosus) and the white-collared mangabey (C. collaris) of West Africa, the latter easily recognized by the bright red crown of the head. A second group of the genus, Lophocebus (or Semnocebus) is typified by the white-cheeked mangabey (C. albigena) of the equatorial forest-region, in which the head is crested and the eyelids lack bare flesh-coloured rims. The rhesus monkey (Macacus rhesus) of India is the typical representative of the macaques, which may be regarded as the Asiatic representatives of the mangabeys. From that group the macaques differ by their heavier and stouter build (fig. 10), thicker limbs, the presence of large laryngeal sacs, the larger size of the callosities, and the more produced muzzle, while many of them have the tail (which may be absent) much shorter. The nostrils are not terminal, and the hairs are generally ringed. In habits the macaques are much more terrestrial than the mangabeys, some of them being completely so. In the typical group, which, in addition to the rhesus, includes the Himalayan macaque (M. assamensis), the brown macaque (M. arctoides) of Burma and Tibet (fig. 10), the tail may be about equal to half the length of the body or less; but in the Barbary ape, M. (Inuus) inuus, of North Africa and Gibraltar, this appendage is wanting. In a third group (Nemestrinus), represented by the pig-tailed macaque (M. nemestrinus), ranging from Burma to Borneo, and the lion-macaque (M. leoninus) of Siam, the tail, which is carried erect, is about one-third the length of the body. The lion-tailed macaque (M. silenus) of southern India, often miscalled the wanderoo, represents a group by itself (Vetulus) characterized by