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may be applied indifferently to all the members of the first sub-order. "Baboon " appears to be properly applicable to the dog-faced African species, and may therefore be conveniently restricted to the members of the genus Papio and their immediate relatives. "Ape," on the other hand, may be specially used for the tailless man-like representatives of the order; while the term "monkey" may be employed for all the rest, other than lemurs; monkeys being, however, divisible into sub-groups, such as macaques, langurs, guerezas, mangabeys, &c. This usage cannot, however, be universally employed, and the term "monkeys" may be employed for the entire group.

Anthropoidea.-The Primates, as already mentioned, are divisible into two main groups, or sub-orders, of which the first includes man, apes, baboons and monkeys. For this group Professor Max Weber employs the name Simiae (in contradistinction to Prosimiae for the lemurs). Since, however, to take as the title for a group which includes man himself the designation of creatures so much lower in the scale is likely to be repugnant, it seems preferable to employ the designation Anthropoidea for the higher division of the order. As the essential features distinguishing the Anthropoidea from the second sub-order may best be indicated under the heading of the latter, reference may at once be made to some of the more striking characters of the members of the former group. The proportions of the body as regards the relative lengths of the two pairs of limbs to one another and to that of the trunk vary considerably. Both pairs may be much elongated, as in Ateles and Hylobates, and either sub-equally, as in the first of these, or with the arms greatly in excess, as in the second. The legs may be excessively short, and the arms, at the same time, excessively long, as in the orang-utan. Both pairs may be short and sub-equal, as in many of the baboons (Papio). Only in Nyctipithecus and the Hapalidae does the excess in length of the lower limbs over the upper exceed or equal that which is found in man. The length of the tail presents some noteworthy points. It is found at its greatest absolute length, and also greatly developed relatively, being about twice the length of the trunk, in such monkeys as the Indian langurs; but its greatest relative length is attained in the spidermonkeys (Ateles), where it reaches three times the length of the trunk. The constancy of the degree of its development varies much in different groups. In the greater number of genera it is long in all the species, and in some (Simia, Anthropopithecus and Hylobates) it is absent in all. In others it may he long or short, or completely absent, as in macaques (Macacus).

The form of the head presents great differences-it may be rounded, as in Ateles; produced vertically, as in Simia; drawn out posteriorly to an extreme degree, as in Chrysothrix; or anteriorly, as in the baboons. A production of the muzzle, necessitated by the presence of large teeth, exists in the chimpanzee (Anthropopithecus), but in the baboons, not only is this prolongation carried farther, but the terminal position of the nostrils gives a dog-like aspect to the face.

The eyes may be small compared with the size of the head, as in the baboons; but they may, on the contrary, attain a relatively enormous size, as in Nyctipithecus. They are always forwardly directed, and never much more separated one from another than in man; they may, however, be more closely approximated, as in the squirrel-monkeys (Chrysothrix) of South America.

The ears are always well developed, and very generally have their postero-superior angle pointed. They may be large and small in the same genus, as in Anthropopithecus (chimpanzee and gorilla); but only in the gorilla do we find, even in a rudimentary condition, that soft depending portion of the human ear termed the "lobule." The nose has scarcely ever more than a slight prominence, and yet an enormous development is to be met with in the proboscis-monkey (Nasalis); while in the snub-nosed monkeys (Rhinopithecus) we find a sharply prominent, though smaller and extremely upturned nose. The hoolock gibbon also possesses a prominent but slightly aquiline nose. The terminal position of the nostrils in the baboons has already been mentioned. These apertures may be closely approximated, as in all the man-like apes (Simiidae and Hylobatidae), or they may be separated one from the other by a broad septum, as in the Cebidae, its breadth, however, varying somewhat in different genera, as in Ateles and Eriodes, and Callithrix and Nyctipithecus. The lips are generally thin, but may be very extensile, as in the orang-utan.

The hands are generally provided with thumbs, though these organs (as in the African guerezas, Colobus, and the American spider-monkeys, Ateles) may be represented only by small nailless tubercles. The thumb is more human in its proportions in the chimpanzee than in any other of the higher apes. As compared with the length of the hand, it is most man-like in the lowest American monkeys, such as Chrysothrix and Hapale. In spite of greater relative length it may, however, little merit the name of thumb, as it is but slightly opposable to the other digits in any of the American monkeys, and is not at all so in the Hapalidae. The "great toe is never rudimentary and, except in man, in place of being the

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longest digit of the foot, is constantly the shortest. As compared with the entire length of the foot, it is most man-like in the chim and next smallest in Hapale. Every digit is provided with a nail, panzee and some gibbons, and smallest of all in the orang-utan, except the great toe of the orang-utan and the rudimentary tubercle representing the thumb in Ateles and Colobus. The nail of the great toe is flat in every species, but the other nails are never so flat as are the nails of man. The lateral compression of the nails becomes more strongly marked in some Cebidae, e.g. Eriodes, but attains its extreme in the Hapalidae, where every nail, except that of the great toe, assumes the form of a long, curved and sharply pointed claw. With the single exception of man, the body is almost entirely clothed with copious hair, and never has the back naked. In the ischiatic callosilies) are present on that part of the body which is gibbons, the langurs, the macaques and the baboons, naked spaces the main support in the sitting posture. These naked spaces are subject to swelling at the season of sexual excitement. Such naked spaces are never found in any of the American monkeys. No ape hair on the head and face as exists in man. As to the head, long or monkey has so exclusive and preponderating a development of hair is found thereon in Hapale oedipus and in some of the langurs monkey (Macacus sinicus), have the hair of the head long and radiatand guerezas, whilst certain macaques, like the Chinese bonneting in all directions from a central point on the crown. A beard is developed in the male orang-utan; and the Diana monkey (Cercopi thecus diana) has long hair on the cheeks and chin. The wanderoo (Macacus silenus) has the face encircled by a kind of mane of long hairs; and many of the marmosets have a long tuft of hairs on each side of the head. American monkeys exhibit some extremes respecting hair-development. Thus in some of the howlers (as in some of the guerezas of the Old World) the hair of the flanks is greatly elongated. Some also have an elongated beard, but the latter structure attains its maximum of development in the couxio (Pithecia satanas). Some of the species of the American genus Pithecia have the hair of the body and tail very long, others have the head of the female furnished with elongated hair; while the allied Uacaria calva has the head bald. Long hair may be developed from the shoulders as in Papio hamadryas and Theropithecus gelada. Very long hair is also developed on the back of the snub-nosed monkeys (Rhinopithecus) in winter. The direction of the hair may sometimes vary in nearly allied forms, the hairs on the arm and fore-arm respectively being often so directed that the tips converge towards the elbow. Such is the case in most of the higher apes, yet in Hylobates agilis all the hair of both these segments is directed towards the wrist. The hair presents generally no remarkable character as to its structure. It may, however, be silky, as in Hapale rosalia, or assume the character of wool, as in the woolly spider-monkeys (Eriodes) and Macacus tibetanus, which inhabits Tibet.

FIG. 2.-Skeleton of Chacma Baboon (Papio porcarius), showing the great relative length of the facial part of the Skull. Great brilliance of colour is sometimes found in the naked parts of the body, particularly in the baboons and some of the other Cercopithecidae, and especially in the regions of the face and sexual organs. Among these latter rose, turquoise-blue, green, goldenyellow and vermilion appear, in various combinations, in one or other or both of these regions, and become especially brilliant at the period of sexual excitement.

The skeleton, more especially in the higher forms, is in the main similar to that of man, so that only a brief notice is necessary. In the skull considerable variation in regard to the proportionate length of the face to that of the brain-case (cranial portion) exists in the two sexes, owing to the general development of large tusks in the males (other than in man, who is not now under consideration), Generally speaking, the elongation of the facial portion, as compared to the cranial, increases as we pass from the higher to the lower forms. The increase does not, however, occur regularly, being

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diminishes, the under surface of the petrosal assumes a swollen of
bladder-like condition.
The plane of the foramen magnum, as compared with the basi-
cranial axis, varies with the projection of the occiput; it generally
forms a less open angle with that axis than in man, but in Chryso
thrix the angle is yet more open than in the human skull. The
cheek, or zygomatic, arches bend outwards and upwards in the
gorilla and some baboons, but decrease in relative as well as absolute
size in the smaller forms-notably in Chrysothrix. No long slender
styloid process is normally attached to the skull, though such may
be the case in the baboons. An external bony auditory meatuse
(or tube) is present in Old World but absent in New World
monkeys. In all apes and monkeys the premaxillae have a distinct-
ness of development and a relative size not found in man; the
sutures separating them from the maxillae remaining visible, except
in the chimpanzee, after the adult dentition has been attained.
The maxillae develop great swollen tuberosities in the baboons
and the black ape of Celebes. The nasal bones are small, and
generally flatter than in man; being in the orang-utan quite flat.
They are convex in some langurs and all baboons; but the proboscis
monkey has its nasals no more developed than those of other species.
The nasals seem to attain their maximum of relative size in the
howlers. The lower jaw, or mandible, is always in one piece in
adults; and is most man-like in the siamang, which alone has
a slight chin. On the other hand, in other gibbons the angle is
produced downwards and backwards, as also in marmosets. Its
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FIG. 4-Skull of adult male Orang-utan (Simia satyrus). In the gorilla the orbits are much as in man, but in the orang-utan they are more rounded. They become very large in Hylobates, but attain an enormous size in the American Nyctipithecus. The extent to which each orbit opens into the adjacent temporal fossa, i.e. the size and shape of the sphenomaxillary fissure, varies considerably; this is narrow and much elongated in the gorilla and the baboons, but short in the langurs and spider-monkeys. It is most closed in the howlers, where it sometimes all but disappears entirely. The mastoid process never attains the large relative size it has in man; but it is prominent in the baboons and larger macaques, as well as in the chimpanzee and gorilla, its development bearing relation to the size and weight of the head. As the mastoid

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maximum of relative size is attained in the howlers (fig. 3), where the broad ascending part serves to protect and shelter the enormously developed body of the hyoid. Air-cells may be developed, as in the gorilla, in the parts adjacent to the mastoid. Frontal sinuses are generally absent in the Old World group, being replaced by coarse cellular bone. In old age the sutures of the skull become obliterated, the one between the two nasals disappearing at an early age in Old World monkeys. In the spider-monkeys and howlers the tentorium, or membrane dividing the hemispheres of the brain from the cerebellum, becomes bonyoque-oroq zied The spinal column of apes and monkeys always lacks the S-like curvature of that of man, the nearest approach to this occurring in the baboons (fig. 2). The number of dorsal vertebrae varies from eleven in some species of Cercopithecus and Macacus to fourteen in certain gibbons or fifteen in the American night-apes (Nyctipithecus). In the American Cebidae the number seldom falls below thirteen; in the orang-utan it is twelve, as in man, but thirteen in the chimpanzee and gorilla. In most cases the dorsal and lumbar regions are about equal in length, but the lumbar region is the shorter in the man-like group, and less than half the length of the dorsal in the gorilla. The lumbar spinous processes are vertical, or project backwards in the man-like apes, gibbons and spider-monkeys; in the others they project forwards, especially in Cebidae. The lumbar transverse processes project outwards, more or less at right angles to the axis of the spine, or else forwards. The sacrum attains its greatest absolute length in the gorilla, but is relatively longer than in man in all the man-like group. Hylobates has the relatively longest sacrum. The number of vertebrae included in the sacrum varies more or less with age; with the excep tion of the Simiidae and Hylobatidae, there are generally only two or three; but in Ateles, Hylobates, and Uacaria there may be four; while in the Simiidae there are always five, and sometimes six. In most apes the sacrum and lumbar vertebrae lie in one slightly curved line, the gorilla and champanzee presenting in this respect a great contrast to the human structure. In the orang-utan the sacrovertebral angle is rather more marked; but in some baboons it is so much so as almost to rival that of man. nagibus evenin

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guerezas, and their allies. It is especially human in shape in Hylobates, except that the pylorus is somewhat more elongated and distinct. It is of a rounded form in Pithecia, and in Hapale the cardiac orifice is exceptionally near the pylorus. In the langur group it is sacculated, especially at the cardiac end, being, in fact, very like a colon spirally coiled. The intestine is devoid of valvulae conniventes, but provided with a well-developed caecum, which is, however, short and conical in the baboons. Only in the man-like apes is there a vermiform appendix. The colon may be much longer relatively than in man, as in the man-like apes; it may be greatly sacculated, as in Hylobates; or devoid of sacculations, as in Cebus. The liver may be very like man's, especially in gibbons, the orangutan, and the chimpanzee; but in the gorilla both the right and left lobes are cleft by a fissure almost as much as in the baboons. In the langur group the liver is much divided, and placed obliquely to accommodate the sacculated stomach. The lateral lobes in Hapale are much larger than the central lobe. The caudate lobe is very large in Cebidae, especially in Ateles, and above all in Pithecia. There is always a gall-bladder.

The larynx in many members of the sub-order is furnished with sac-like appendages, varying in different species as regards number, size and situation. They may be dilatations of the laryngeal ventricle (opening into the larynx below the false vocal chords), as in the man-like apes; or they may open above the false vocal chords so as to be extensions of the thyro-hyoid membrane, as in gibbons. There may be but a single median opening in the front part of that membrane at the base of the epiglottis, as in Cercopithecidae, or there may be a single median opening at the back of the trachea, just below the cricoid cartilage, as in spider-monkeys: and while there is in some instances only a single sac, in other instances, as in the howlers, there may be five. These may be enormous, meeting in the middle line in front, and extending down to the axillae, as in the gorilla and orang-utan. Finally a sac may Occupy the cavity of the expanded body of the hyoid-bone, as in howlers (fig. 3). The hyoid has its basilar part generally somewhat more convex and enlarged than in man; but in howlers it becomes greatly enlarged and deeply excavated, so as to form a great bony bladder-like structure (fig. 3). The cornua of the hyoid are never entirely absent, but the anterior or lesser cornua may be so, as in the howlers. The anterior cornua never exceed the posterior cornua in length; but they may be (Cercopithecus) more developed relatively than in man, and may even be jointed, as in Lagothrix.

The lungs are generally similar to those of man, although, as in gibbons, the right one may be four-lobed. In the man-like apes the great arteries are likewise of the human type; but in the Hylobatidae and Cercopithecidae the left carotid may arise from the innominate. The discoidal and deciduate placenta is generally two-lobed, although single in the howlers; in the marmosets it is unusually thick. American monkeys differ from their Old World

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Man-like Apes.In common with man, the apes and monkeys of the Old World form a section-Catarrhina-of the sub-order Anthropoidea, characterized by the following features: There are only two pairs of premolar teeth, so that the complete dental formula is i, , c. I. p. 1. m. j. The tympanum has an external bony tube, or meatus; but there is no tympanic bulla. A squamoso frontal suture causes the frontal and the alisphenoid bones to enter largely into the formation of the orbital plate; and the orbito temporal foramen is small. Cheek-pouches and callosities on the buttocks are frequently present. The nails are flat or rounded, the descending colon of the intestine has an S-like (sigmoid) flexure;

FIG. 8.-Adult Male Gorilla (Anthropopithecus gorilla). the caecum is simple, and there may be a vermiform appendix. The inter-nasal septum is thin, and the nostrils are directed outwards. The tail, which may be rudimentary, is never prehensile. The ethmoturbinal bones of the nasal chamber are typically united. Laryngeal sacs are commonly developed. In addition to the primary discoidal placenta, a secondary, and sometimes temporary one is developed.

It does not come within the province of this article to treat of man (see ANTHROPOLOGY); but it may be mentioned that the distinctive characteristics of the family Hominidae (including the single genus Homo), as compared with those of the Simiidae, or man-like apes, are chiefly relative. These are shown by the greater size of the brain and brain-case as compared with the facial portion of the skull, smaller development of the canine teeth of the males, more complete adaptation of the structure of the vertebral column to the vertical position, greater length of the lower as compared with the upper extremities, and the greater length of the great toe, with almost complete absence of the power of bringing it in opposition to the other four toes. The last and the small size of the canine teeth are perhaps the most marked and easily defined distinctions that can be drawn between the two groups, so far as purely zoological characters are concerned, The regular arch formed by the series of teeth is, however, as already mentioned, another feature distinguishing man from the man-like apes.

In common with the gibbons (Hylobatidae) the man-like apes, or Simiidae, are distinguished from the lower representatives of the present sub-order by the following features: The sternum is short and broad, and the thorax wide and shallow (fig. 6), while the pelvis, as shown in the same figure, is more or less laterally expanded, and hollow on its inner-surface; and the number of dorso-lumbar vertebrae ranges from sixteen to eighteen. The arm is longer than the leg; and while the hair on the fore-arm is directed upwards, that of the upper-arm slopes downwards to meet it at the elbow. Cheek-pouches are absent. The cusps of the molars are separate; and five in number above and four below. The caecum has a vermito fagoithe na form appendix; and the secondary placenta merely forms a temporary fold. The Simiidae are specially characterized by the absence of callosities on the buttocks; the presence of sixteen or seventeen dorso-lumbar vertebrae, and of twelve or thirteen pairs of ribs; the wrinkling of the enamel of the cheek-teeth; the great expansion and concavity of the iliac bones of the pelvis; and the application of only the edge of the sole of the foot to the ground in walking.

(From a sketch by Wolf from life.)ob Jasen FIG. 7.-An Immature Chimpanzee (Anthropopithecus troglodytes). cousins in having two umbilical veins in place of a single one. In the Cercopithecidas gestation lasts about seven months, but in the marmosets is reduced to three. The young, which are generally carried on the breast, are suckled for about six months in most monkeys.

The existing members of the family are referable to at least two genera, the one African and the other Asiatic. The first genus, Anthropopithecus, is typified by the West African chimpanzee, A. troglodytes (fig. 7), and is characterized by the absence of excessive elevation in the skull, by the fore limb not reaching more than half-way down the shin, the presence of thirteen pairs of ribs, the well-developed great toe, the absence of a centrale in the carpus, and the black or grey hair. There is a well-developed laryngeal sinus, which may extend downwards to the axilla. Chimpanzees are characterized by the large size of the ears, and typically by the small development of the supra-orbital ridges. The latter are, however, more developed in the Central African A. tchego (of which the kulu-kamba is a local phase); this form-whether regarded as a species or a race-being thus more gorilla-like (see CHIMPANZEE). The gorilla (Anthropopithecus gorilla, fig. 8), of which there are likewise several local forms, ranging from the West Coast through the forest-tract to East Central Africa, and apparently best regarded as sub-species, is frequently made the type of a second genus Gorilla; but is extremely close to the chimpanzee, from which it is perhaps best distinguished by its much smaller ears. It is the largest of the apes, although the females are greatly inferior in stature and bulk to the males. The gorilla is also a much less completely arboreal ape than the chimpanzee, in consequence of which more of the sole of the foot is applied to the ground in walking. The enormous supra-orbital ridges of the skull of the male, and likewise the large and powerful tusks in that sex are very characteristic. A full-grown gorilla will stand considerably over six feet in height. According to Dr A. Keith, in addition to its smaller and flatter ears, the gorilla may be best distinguished from the chimpanzee by the presence of a nasal fold running to the margin of the upper lip; by the large size and peculiar characters of the tusks and cheekteeth; by its broad, short, thick hands and feet, of which the fingers and toes are partially webbed; by the long heel; and by the relative length of the upper half of the arm as compared with the fore-arm. An important distinctive feature of the skull of the gorilla is the great length of the nasal bones. Finally, in adult life the gorilla is sharply differentiated from the chimpanzee by its sullen, untameable, ferocious disposition.

As regards the relationship existing between the gorilla and the chimpanzee, Dr Keith observes: An examination of all the structural systems of the African anthropoids leads to the inference that the gorilla is the more primitive of the two forms, and approaches the common parent stock more nearly than does the chimpanzee. The teeth of the gorilla, individually and collectively, form a complete dentition, a dentition at the very highest point of development; the teeth of the chimpanzee show marked signs of retrogression in development both in size and structure. The muscular development and the consequent bony crests for muscular attachment of the gorilla far surpass those of the chimpanzee. The muscular development of the adult chimpanzee represents that of the adolescent gorilla. Some of the bodily organs of the gorilla belong to a simpler and earlier type than those of the chimpanzee. But in one point the chimpanzee evidently represents more nearly the parent form-its limbs and body are more adapted for arboreal locomotion; of the two, the gorilla shows the nearer approach to the human mode of locomotion. On the whole the evidence at our disposal points to the conclusion that the chimpanzee is a derivative from the gorilla stock, in which, with a progressive brain development, there have been retrograde changes in most of the other parts of the body. The various races of chimpanzee differ according to the degree to which these changes have been carried." (See GORILLA.)

From both the chimpanzee and the gorilla the orang-utan, or mias (Simia satyrus), of Borneo and Sumatra is broadly distinguished by the extreme elevation of the skull (fig. 4), the excessive length of the fore limbs, which reach to the ankle, the presence of only twelve pairs of ribs and of a centrale in the carpus, the short and rudimentary great toe, and the bright-red colour of the hair. Adult males are furnished with a longish beard on the chin, and they may also develop a large warty prominence, consisting of fibrocellular tissue, on each side of the face, which thus assumes an extraordinary wide and flattened form. There is no vestige of a tail. The hands are very long; but the thumb is short, not reaching the end of the metacarpal bone of the index-finger. The feet have exceedingly long toes, except the great toe, which only reaches to the middle of the first joint of the adjacent toe, and is often destitute not only of a nail, but of the second phalange also. It nevertheless possesses an opponens muscle. The brain has the hemispheres greatly convoluted, and is altogether more like the brain of man than is that of any other ape. A prolongation is developed from each ventricle of the larynx, and these processes in the adult become enormous, uniting together in front over the windpipe and forming one great sac which extends down between the muscles to the axilla. The canine teeth of adult males are very large. In Borneo the orang-utan displays great variability, and has accordingly been divided into a number of local races, in some of which the males

It has been proposed to transfer the name Simia to the chimpanzee, on the ground that it was originally given to that animal.

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apparently lack the lateral expansion of the face. Whether the Sumatran orang-utan should be regarded as a distinct species, with two local races, may be left an open question. (See ORANG-UTAN). Gibbons.-The comparatively small, long-armed and tailless Asiatic apes known as gibbons have been very generally included in the same family as the man-like apes, but since they differ in several important features-to say nothing of their smaller bodily size-it has recently been proposed to refer them to a family apart, the Hylobatidae. The distinctive features of this family include the presence of small naked callosities on the buttocks, the possession of eighteen dorso-lumbar vertebrae and thirteen pairs of ribs, the absence of foldings in the enamel of the molar teeth, the slight lateral expansion and concavity of the iliac bones of the pelvis, and the application of the whole sole of the foot to the ground in walking. The vertebral column presents no trace of the sigmoid flexure which is developed partially in the Simiidae and completely in the Hominidae. None of the gibbons have any rudiment of a tail; and the canines are elongated and tusk-like. When the body is erect, the arms are so long that they reach the ground. The great toe is well developed, reaching to the middle or end of the first joint of the adjacent toe; but the thumb only attains to, or reaches a little beyond, the upper end of the first joint of the index-finger. There is a centrale in the carpus. The laryngeal sacs are no longer prolongations of the laryngeal ven tricles, but open into the larynx above the false vocal chords. The group is distributed throughout the forest-regions of south-eastern Asia, eastwards and southwards from Assam, and is represented by a considerable number of species. Among these, the siamang, Hylobates syndactylus, of Sumatra and the Malay Peninsula, differs from all the rest by the union of the index and third fingers up to the base of their terminal joints, in consequence of which this species is regarded as representing a sub-genus (Symphalangus) by itself, while all the others belong to Hylobates proper. The general colour of gibbons is either pale fawn or black, with or without a white band across the forehead. In a female from Hainan in the menagerie of the Zoological Society of London, the colour of the coat changed from black to fawn about the time full maturity was attained. Apparently no such change takes place in the male. According to Dr W. Volz, the two banks of the Lematang River in the Palembang district of Sumatra are respectively inhabited by two different species of gibbons-on the west bank is found the siamang (Hylobates syndactylus), while the country to the east of the river is the home of the agile gibbon, or waw-waw (H. agilis). It is not necessary to capture, or even to see, specimens of the two species in order to satisfy oneself as to their limitations, for they may be readily distinguished by their cries: the siamang calling in a single note, whereas the cry of the waw-waw forms two notes. The remarkable thing about their distribution in Palembang is that the two species are found in company throughout the rest of Sumatra; and even in Palembang itself they inhabit the mountain districts, where the river is so narrow that they could easily leap over it, and yet they keep to the opposite banks. Gibbons are perhaps the most agile of all the Old World monkeys, rivalling in this respect the American spider-monkeys, despite their lack of the prehensile tails of the latter (see GIBBON).

Langur Group.-The well-known long-tailed langur monkeys of India and the adjacent regions are the first representatives of the third family of apes and monkeys, which includes all the remaining members of the sub-order now under consideration. In the Cercopi thecidae, as the family is called, the following features are distinctive: The sternum, or breast-bone, is narrow and elongated, and the thorax compressed and wedge-shaped, while the iliac bones of the pelvis are narrow, with the inner surface flat; the dorso-lumbar vertebrae are nineteen or twenty in number. The front limbs are shorter than the hind pair; the whole sole of the foot is applied to the ground in walking; and the hair on the arm is directed downwards from the shoulder to the hand. There are always bare callosities on the buttocks, and very generally cheek-pouches. The caccum is conical. Transverse ridges connect the cusps of the molars. The secondary placenta is fully developed.

The first group of the family is represented by the langurs and their allies, collectively forming the sub-family Semnopithecinae, in which the tail and hind limbs are very long, and the body is slender; there are no cheek-pouches, but, on the other hand, the stomach is complicated by sacculations or pouches, and the last lower molar has a posterior heel, thus carrying five cusps. The thumb is small or absent, the callosities on the buttocks are also small, and the nails are narrow and pointed. The laryngeal sac (or throat-sac) opens in the middle line of the front of the larynx, and is formed by an extension of the thyro-hyoid membrane. The true langurs, of the genus Semnopithecus, in which a small thumb is retained, form a large group confined to south-eastern Asia, where it ranges from India and the Himalaya to Borneo and Sumatra by way of Burma, Cochin China and the Malay Peninsula. A well-known representative is the sacred hanuman monkey (S. entellus) of India, which, like the larger Himalayan S. schistaceus, is slate-coloured; the Bornean S. hosei, on the other hand, is wholly maroon-red. Other species, like the Indian S. johni, have the head crested. The allied genus Rhinopithecus, as typified by the orange

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