Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.
|
See also:CHIROPTERA (See also:Greek for " See also:hand-wings ") , an See also:order of mammals containing the bats, all of which are unique in the class in possessing the See also:power of true See also:flight, and have their fore-limbs specially modified for this purpose . The mammals comprised in this order are at once distinguished by the See also:possession of true wings; this peculiarity being accompanied by other modifications of bodily structure having relation to aerial locomotion . Thus, in See also:direct contrast to all other mammals, in which locomotion is chiefly effected by See also:action from behind, and the See also:hind-limbs consequently greatly preponderate in See also:size over the fore, in the See also:Chiroptera the fore-limbs, being the agents in propelling the See also:body forward during flight, immensely exceed the See also:short and weak hinder extremities . The See also:thorax, giving origin to the See also:great muscles which sustain flight, and containing the proportionately large lungs and See also:heart, is remarkably capacious; and the ribs are flattened and See also:close together; while the See also:shoulder-See also:girdle is greatly See also:developed in comparison with the weak See also:pelvis . The fore-See also:arm (fig. r) consists of a rudimentary ulna, a See also:long curved See also:radius, and a carpus of six bones supporting a thumb and four elongated fingers, between which, the sides of the body, and the hinder extremities a thin expansion of skin, the wing-membrane, is spread . The See also:knee is directed backwards, owing to the rotation of the hind-See also:limb, outwards by the wing-membrane; an elongated cartilaginous See also:process (the See also:calcar), rarely rudimentary or absent, arising from the inner See also:side of the See also:ankle-See also:joint, is directed inwards, and supports See also:part of the posterior margin of an See also:accessory membrane of flight, extending from the tail or posterior extremity of the body to the hind-limbs, and known as the inter-femoral membrane . The penis is pendent; the testes are abdominal or inguinal; the teats, usually two in number, thoracic; the uterus is See also:simple or with more or less long cornua; the See also:placenta discoidal and deciduate; and the smooth cerebral hemispheres do not extend backwards over the cerebellum . The See also:teeth comprise incisors, canines, premolars and molars., and the dental See also:formula never c, Clavicle . h, Humerus . r, Radius . u, Ulna . dt, First See also:digit . d2, d3, d4, d', Other digits of the fore-limb supporting wm, the wing-membrane . m,m, Metacarpal bones . ph', First See also:phalanx . ph', Second phalanx . phi, Third phalanx . am, Antebrachial membrane . f, Femur . t, See also:Tibia . fb, Fibula . [femoral membrane . c, Calcar supporting See also:im, the interpcl, See also:Post-calcaneal See also:lobe . exceeds i . , c . 1, p . 1, m . 1; See also:total 38 . Despite the forward position of the teats, which is merely an adaptive feature, bats are evidently mammals of See also:low organization, and are most nearly related to the Insectivora . In consequence of the backward direction of the knee, a See also:bat, when placed on the ground, rests on all fours, having the knees directed upwards, while the See also:foot is rotated forwards and inwards on the ankle . Walking is 'thus a See also:kind of shuffle; but, notwithstanding a See also:general belief, bats can take wing from the walking posture . The bones of the See also:skeleton are characterized by their slenderness and the great size of the medullary canals in those of the extremities . The vertebral See also:column is short, and the vertebrae differ but slightly in number and See also:form throughout the See also:group . The general number of dorso-lumbar vertebrae is 17, whereof 12 are dorsal; the cervical vertebrae are broad, but short . Except in See also:fruit-bats (Pteropodidae), the vertebrae, from the third cervical backwards, are devoid of spinous processes . From the first dorsal to the last lumbar the vertebral column forms a single See also:curve, most pronounced in the lumbar region . The bodies of the vertebrae are but slightly movable on each other, and in old individuals become partially welded . The caudal vertebrae are cylindrical bones without processes; their number and length varying in allied See also:species . The development of these vertebrae is correlated with habits, the long tail in the insectivorous species supporting and controlling the position of the interfemoral membrane which See also:aids bats in their doubling motions when in pursuit of See also:insects by acting as a See also:rudder, and assists them in the See also:capture of the larger insects . In the fruit-bats this is not required, and the tail is rudimentary or absent . In all bats the presternum has a prominent See also:keel for the See also:attachment of the great See also:pectoral muscles . The shape of the See also:skull varies greatly; but post-orbital processes are developed only in some Pteropodidae and a few Nycteridae and Emballonuridae; in Pteropus leucopterus alone does a process from the zygomatic See also:arch meet the post-orbital so as to See also:complete the orbital See also:ring . Zygomatic See also:arches, though slender, are See also:present in all except in some of the species of Phyllostomatidae . The See also:milk-teeth differ from those of all other mammals in that they are unlike those of the permanent See also:series . They are slender, with pointed recurved cusps, and are soon See also:shed, but exist for a short See also:time with the permanent teeth . In the Rhinolophidae the milk-teeth are absorbed before See also:birth . The permanent teeth exhibit great variety, sometimes even in the same See also:family, as in Phyllostomatidae, whilst in other families, as Rhinolophidae, the resemblance between the dentition of species differing in many respects is remarkable . In all they are provided with well-developed roots, and their crowns are acutely tuberculate, with more or less well-defined W-shaped cusps, in the insectivorous species, or variously hollowed out or longitudinally grooved in the frugivorous kinds . The shoulder-girdle varies but slightly, the clavicle being long, strong and curved; and the scapula large, See also:oval and triangular, with a long curved coracoid process . The humerus, though long, is scarcely two-thirds the length of the radius; and the rudimentary ulna is welded with the radius . A sesamoid See also:bone exists in the tendon of the triceps muscle . The upper See also:row of the carpus consists of the See also:united scaphoid, lunar and See also:cuneiform bones . The " See also:hand " has five digits, the first, See also:fourth and fifth of which consist each of a metacarpal and two phalanges; but in the second and third the number of phalanges is different in certain families . The first digit terminates in a claw, most developed in the frugivorous species, in most of which the second digit is also clawed, although in other bats this and the remaining digits are unarmed . In the weak pelvis the ilia are long and narrow, while in most species the pubes of opposite sides are loosely united in front in See also:males, and widely separated in See also:females; in the Rhinolophidae alone they form a symphysis . Only in the Molossinae is there a well-developed fibula; in the See also:rest this bone is either very gender or cartilaginous and See also:ligament 'us in its upper third, orreduced to a small bony process above the See also:heel, or absent . The foot consists of a short See also:tarsus, and of slender, laterally compressed toes, with much-curved claws . Although the See also:brain is of a low type, probably no animals possess so delicate a sense of See also:touch as Chiroptera . In See also:ordinary bats tactile See also:organs exist, not only in the bristles on the sides of the muzzle, but in the sensitive structures forming the wing-membranes and ears, while in many species See also:leaf-like expansions surrounding the nasal apertures or extending backwards behind them are added . These See also:nose-leaves are made up partly of the extended and thickened integument of the nostrils, and partly of the glandular eminences occupying the sides of the muzzle, in which in other bats the sensitive bristles are implanted . In no mammals are the ears so developed or so variable in form; in most insectivorous species they are longer than the See also:head, while in the long-eared bat their length nearly equals that of the head and body . The form is characteristic in each of the families; in most the " earlet," or tragus, is large, in some cases extending nearly to the See also:outer margin of the See also:conch; its See also:office appears to be to intensify and prolong the waves of See also:sound by producing undulations in them . In the Rhinolophidae, the only family of insectivorous bats wanting the nag*, the auditory bullae reach their greatest size, and the nasal appe adages their highest development . In frugivorous bats the See also:ear is simple and but slightly variable . In all bats the ears are extremely See also:mobile, each independently at will . The See also:oesophagus is narrow, especially in See also:blood-sucking vampires . The See also:stomach 'presents two types of structure, corresponding respectively to the two divisions of the order, Megachiroptera and Microchiroptera; in the former the pyloric extremity is, with one exception, elongated and folded upon itself, in the latter simple; an exceptional type is met with in the blood-suckers, where the cardiac extremity is elongated, forming a long appendage . The See also:intestine is comparatively short, varying from one and a See also:half to four times the length of the head and body; longest in the frugivorous, shortest in the insectivorous species . In Rhinopoma and Megaderma a small caecum has been found . The See also:liver is characterized by the great size of the See also:left lateral lobe, which occasionally equals half that of the whole See also:organ; the right and left lateral fissures are usually very deep; in Megachiroptera the spigelian lobe is, with one exception, See also:ill defined or absent, and the caudate is generally large; but in Microchiroptera the former lobe is large, while the caudate is small . The See also:gall-See also:bladder is generally well developed . In most species the hyoids are simple, consisting of a See also:chain of slender, long, cylindrical bones connecting the basi-hyoid with the skull, while the pharynx is short, and the larynx shallow with feebly developed vocal cords, and guarded by a short pointed epiglottis . In the See also:African epauletted bats, Epomophorus, the pharynx is long and capacious, the See also:aperture of the larynx far removed from the See also:fauces, and, opposite to it, opens a See also:canal, leading from the nasal See also:chambers, and extending along the back of the'pharynx; the laryngeal cavity is spacious and its walls are ossified; the hyoids are unconnected, except by muscle with the skull; while the cerato-hyals and epi-hyals are cartilaginous and See also:expanded, entering into the formation of the walls of the pharynx, and (in males of some species) supporting the orifices of a pair of See also:air-sacs communicating with the pharynx (fig . 2) . The extent and shape of the wings generally depend on the form of the bones of the fore-limbs, and on the presence or See also:absence of the tail . The wings consist of an "antebrachial membrane," which extends from the point of the shoulder along the humerus and more or less of the fore-arm to the See also:base of the thumb, the metacarpal bone of which is partially or wholly included in it; the " wing-membrane " spread out between the elongated fingers, and extending along the sides of the body to the posterior extremities, generally reaching to the feet; and the " interfemoral membrane," the most variable of all, which is supported between the extremity of the body, the legs and the calcar (fig. n) . The antebrachial and wing membranes are most developed in species fitted only for aerial locomotion which when at rest hang with the body enveloped M.1the wings; but in the Emballonuridae, and also in the Molossinae, which are the best fitted for terrestrial progression, the antebrachial membrane is reduced to a small size, and not developed along the fore-arm, leaving the thumb quite See also:free, while the wing- membrane is narrow and folded in repose under the fore-arm . The relative development of the interfemoral membrane has been referred to in connexion with the caudal vertebrae . Its small size in the frugivorous and blood-sucking species, which do not require it, is easily under-stood . See also:Scent-glands and pouches opening on the See also:surface of the skin are developed in many species, but in most cases more so in males than in females (fig . 3) . As a See also:rule, bats produce only a (Phyllorhinalarvata) . From See also:Dobson . about by the See also:female See also:parent clinging to the See also:fur of her See also:breast; but certain See also:North See also:American bats commonly give birth to three or four See also:young ones at a time, which are carried about in the same manner .
Bats are divisible into two suborders, Megachiroptera and Microchiroptera
.
Megachiroptera
.
The first of these comprises the fruit-eating species, which are generally of large size, with the crowns of the cheek-teeth smooth and marked with a See also:longitudinal groove
.
The bony See also:palate is continued behind the last molar, narrowing slowly backwards; there are three phalanges in the See also:index See also:finger, the third phalange being terminated generally by a claw; the sides of the ear form a ring at the base; the tail, when present, is inferior to (not contained in) the interfemoral membrane; the pyloric extremity of the stomach is generally much elongated; and the spigelian lobe of the liver is ill-defined or absent, while the caudate is well developed
.
This group is limited to the tropical and sub-tropical parts of the Eastern Hemisphere
.
All the members of this suborder are included in the single family Pteropodidae, the first representatives of which are the African epauletted bats, forming the genus Epomophorus
.
In this the dental formula is i
.
1 (or 2), c
.
}, p
.
, m
.
Tail short or absent, when present free from the interfemoral membrane; second finger with a claw; premaxillae united in front
.
The species are strictly limited to See also:Africa See also:south of the See also:Sahara, and are distinguished by the large and long head, expansible and often folded lips, and the See also: The males are provided with glandular pouches, situated in the skin of the side of the See also:neck near the point of the shoulder, which are rudimentary or absent infemales . In the males they are lined with glandular membrane, from which long coarse yellowish hairs project to form conspicuous epaulet-like tufts on the shoulders . The males often have a pair of air-sacs extending outwards on each side from the pharynx beneath the integument of the neck, in the position shown in fig . 2 . These bats appear to live principally on See also:figs, the juicy contents of which their voluminous lips and capacious mouths enable them to See also:swallow without loss . The huge and ugly See also:West African See also:hammer-headed bat, Hypsignathus monstrosus, represents an allied genus distinguished by the absence of shoulder- pouches, and the presence of leaf-like expansions of skin on the front of the muzzle, and of distinct cusps on the outer sides of the cheek-teeth . The great See also:majority of the bats of this group, commonly known as " flying-foxes," are included in the typical genus Pteropus, of which the dental formula is i . I, c . , p . m . . All are of large size, and the absence of a tail, the long pointed muzzle, and the woolly fur covering FIG . 4.-Head of a Flying-See also:Fox or the neck render their recog- Fruit-Bat (Pteropus personatus) .
From nition easy
.
One of the See also: The dentition is i . 2 c. p . 3r m. the muzzle is 2 Or I' shorter than in Roussettus, with the upper See also:lip grooved in front as in Pteropus, while the tail and fur resemble those of the former genus . These bats are extremely voracious, a specimen of the Indian C. marginatus having eaten a See also:banana twice its own See also:weight in three See also:hours . Among several Austro-Malay genera, such as Ptenochirus and Balicnycteris, the See also:tube-nosed bats of the genus Gelasinus (or Herpyia) are remarkable for the conformation of the nostrils (fig . 5) . Cephalotes, with one species, ranging from Celebes to the See also:Solomon group, has the dentition 1 . J, c . I, p. a, m. pre- maxillae not united in front, nostrils simple, muzzle short, index finger without a claw, tail short . As in Gelasinus, the wing-membrane arises from the See also:middle See also:line of the back, to which it is attached by a FIG . 5.-Head of Papuan Tube-Nosed longitudinal thin process Bat (Gelasinus See also:major) . From G . E. of skin; the wings are Dobson . naked, but the back covered with hair . Leipenyx is an allied West African genus with one species . The foregoing belong to the typical subfamily Pteropodinae, while the See also:remainder represent a second group, Carponycterinae (or Macroglossinae), characterized by having the facial part of the skull produced, the molar teeth narrow, and scarcely raised above the See also:gum, and the See also:tongue exceedingly long, attenuated in the anterior third, and armed with long recurved papillae near the tip . The single representative of the first genus, Notopteris macdonaldi, inhabiting See also:Fiji, New Guinea and the New See also:Hebrides, is distinguished from other bats of this family by the length of its tail, which is nearly as long Fruiteating bats . as the forearm . The dentition is i. c . }, p . , in . , while the index finger has no claw, and the wings arise from the spine . Eonycteris, with the dentition i . I, c . }, p . B, m . 'y, is also represented by a single species, E. spelaea, from See also:Tenasserim, Burma, and the Malay See also:Peninsula and Islands, which has somewhat the See also:appearance of a Roussettus, but the absence of a claw in the index finger and the presence of the characteristic tongue and teeth at once distinguish it . Carponycteres (Macroglossus) and Melonycteris, the former with several and the latter with a single species, are closely allied Indo-Malay and Papuan genera, the index finger in both having a claw, but the number of the teeth being the same as in Eonycteris . C. See also:minim= is the smallest known species of the suborder, much smaller than the serotine bat of See also:Europe, with the fore-arm scarcely longer than that of the long-eared bat . It is nearly as common in certain parts of Burma as Cynopterus marginatus, and extends eastwards through the Malay Archipelago as far as New Ireland, where it is associated with Melonycteris melanops, distinguished by its larger size and the total absence of the tail . An allied small Carpopycteris inhabits India . Trygenycteris (Megaloglossus) woermanni, of West Africa, is the only member of the group occurring west of the See also:Himalaya . Callinycterts of Celebes, with the dentition a . I, c . 1, p . I, in., has a short tail and no index-claws, while Nesonycteris of the Solomons, with the dentition i . I, c . }, p . R, m. differs by the absence of the tail . Microchiroptera . The second and larger suborder, the Microchiroptera, includes all the insectivorous species, the majority of which are of relatively See also:Insect- small size as compared with the Megachiroptera . In these eating bats, with a few specialized exceptions, the crowns of the bats . cheek-teeth are surmounted by See also:sharp cusps, divided by transverse grooves . In the skull the bony palate narrows abruptly and is not continued backwards laterally behind the last molar; there is one rudimentary phalange (rarely two or none) in the index finger, which is never terminated by a claw; the outer and inner sides of the ear commence inferiorly from separate points of origin; the tail, when present, is contained in the interfemoral membrane, or appears on its upper surface; the stomach, except in the blood-sucking group, is simple; and the spigelian lobe of the liver large, and the caudate generally small . The bats included in this suborder are so numerous in genera (to say nothing of species) that only some of the more important types can be mentioned) . Brief references have already been made to the manner in which in many or most of these bats the tail aids in the capture of See also:prey . From the observations of C . See also:Oldham, it appears that these bats, when walking, carry the tail downwards and forwards, so that the membrane connecting this organ with the hind-legs forms a kind of pouch or bag . If a large insect be encountered the bat seizes it with a snatch, and slightly spreading its folded wings and pressing them on the ground in order to steady itself, brings its feet forwards so as to increase the capacity of the tail-pouch, into which, by bending its neck and thrusting its head beneath the body, it pushes the insect . Although the latter, especially if large, will often struggle violently, when once in the pouch it but rarely escapes, from which it is subsequently extracted and devoured . It is assumed that the same method of capture is employed when on the wing; and a naturalist who has observed the long-eared bat picking moths off willows states that the bat always hovers when taking off the See also:moth, and bends up the tail so as to form a receptacle for the insect as it drops . In the Rhinolophidae, See also:Horse-See also:shoe and Leaf-nosed bats of the Old See also:World, the nose-leaf is developed and surrounds the nasal apertures, which are situated in a depression on the upper surface of the muzzle so as to look upwards; the ears are large and generally separate, without trace of a tragus or earlet; the premaxillae are rudimentary, suspended from the nasal cartilages, and support a single pair of small incisors; the molars have acute W-shaped cusps; the skull is large, and the nasal bones which support the nose-leaf much expanded vertically and later-ally . In females a pair of teat-like appendages are found in front of the pubis; and the long tail extends to the margin of the interfemoral membrane . The middle finger has two phalanges, but the index is rudimentary . The fibula is rudimentary . The Rhinolophidae are the most highly organized of insectivorous bats, in which the osseous and cutaneous systems reach the fullest development . Compared with theirs, the bones of the extremities and the wings of other bats appear coarsely formed, and their teeth seem less perfectly fitted to crush the hard bodies of insects . The complicated nasal appendages reach their highest development, and the See also:differences in their form afford characters in the discrimination of the species, which resemble one another closely in dentition and the See also:colour of the fur . In the first subfamily, Rhinolophinae, the first toe has two, and theother toes three phalanges each; and the ilio-pectineal spine is not connected by bone with the antero-inferior surface of the ilium . In the horseshoe bats, Rhinolophus, the dentition is i .
, c. p. m. the nose-leaf has a central process behind and between the nasal orifices, with the posterior extremity lanceolate, and the antitragus large
.
Among the numerous forms R. luctus is the largest, and in-habits elevated See also: } p . , or m 4, . I., differs from Rhinolophus in the form of the nose-leaf, which is not lanceolate behind (fig . 6), and is unprovided with a central process covering the nostrils; the largest species, H. armiger, appears to be the most northerly, having been taken at See also:Amoy in See also:China, and in the Himalaya at an See also:elevation of 5500 ft . Many are provided with a frontal See also:sac behind the nose-leaf, rudimentary in females (see fig . 7), which can be everted at See also:pleasure; the sides of this sac secrete a waxy substance, and its extremity sepports a tuft of straight hairs . Rhinonycteris, represented by R. aurantia from Australia, and Triaenops. by T. persicus from See also:Persia and other species from Africa and Madagascar, are closely allied genera . Triaenops (fig . 8) is characterized by the remark-able form of its nasal appendages and ears, and the presence of a bony See also:projection from the upper extremity of the second phalange of the fourth finger . Coelops (C . Frilhi), from the See also:Bengal Sanderbans, FiG . 8.—Head of See also:Persian Leaf-Java and See also:Siam. is distinguished Bat . (Triaenops persicus) . From by the See also:peculiar form of its obson . nose-leaf and the length of the D metacarpal bone of the index finger, as well as by the shortness of the calcar and interfemoral membrane . Cloeotis is represented by a single East African species, and Anthops by one from the Solomon Islands characterized by the nose-leaf covering the whole front of the See also:face . The next family, Nycteridae, which is also Old World, is a small one, nearly allied to the last, in which it is included by Prof . Max See also:Weber as a subfamily under the name of Myader- False matinae . It differs by the presence of a small tragus in vampires. the ears, which are united at their bases; and , by the nasal chamber not being inflated . The premaxillae are either small and separated in front, or rudimentary; and the first phalange of the middle finger when in repose is laid back on the metacarpus . There are only pectoral teats . Of the two genera, Megaderma, as represented by the five species of false vampires, is distinguished by the absence of ossified pre-maxillae and upper incisors (i. zi p . 2-21:9 , the cylindrical narrow muzzle surmounted by an erect nose-leaf the base of which conceals the nasal orifices, the immense joined ears with large bifid tragus, and the great extent of the interfemoral membrane, in the base of which the short tail is concealed . M. gigs (fig . 9), from central See also:Queensland, is the largest species of the genus, and of the suborder . M . Tyra, common in India (fore-arm 2.7 in.), has been caught in the See also:act of sucking the blood, while flying, from a small bat which it afterwards devoured . The range of the genus includes Africa, the Indo-Malay countries and Australasia . Nycteris, which is 'ommon to Africa and the Malay Peninsula and Islands, has ossified prey forma: In the first subfamily, Mormopsinae (Lobostominae), the maxillae and upper incisors (i . , p . 1), and a long tail, but lacks.a nose-leaf . As in Megaderma, the frontal bones are deeply hollowed and expanded laterally, the muzzle presents a similar cylindrical form, and the See also:lower See also:jaw also projects; but, instead of a nose-leaf, the face is marked by a deep longitudinal sharp-edged groove ex- tending from the nostrils to the See also:band connecting the base of the large ears; the sides of this depression being margined as far back as the eyes by small See also:horizontal cutaneous appendages . With the exception of N. javanica, the species are limited to Africa . According to the See also:classification followed by Dr G . E . Dobson, the extensive family of New World bats known as Phyllostomatidae was d e vampires . Prof . Max Wereebderfr'som syst mt theyreare ceding a1 See also:ged See also:net but in one another—an arrangement which has the great See also:advantage of bringing together all the bats furnished with nose-leaves . It is indeed probable that the vampires, as the members of the present family may be collectively termed, are the New World representatives of the Old World Rhinolophidae and Nycteridae . The Phyllostomatidae are characterized by the presence of a nose- leaf, or of lappets on the See also:chin, but the nostrils are not directed upwards . The ethmoturbinal bones of the nasal cavity form simple plates (much as in the two preceding families) . The premaxillae are always well developed, with their palatal portions forming a suture and defining the boundaries of distinct See also:palatine foramina (in See also:place of being rudimentary, as in Nycteridae and Rhijtolophidae) . The large ears have a tragus . The middle finger has three phalanges, and the index one . There is an incomplete fibula . The, tail may be either long orshort . Generally the dentition is i.#, c. p. m . . All the bats of this family may be readily recognized by the presence of a well-developed third phalange in the middle finger, associated either with a distinct nose-leaf, or with central upper in- cisors, or with both .
Unlike the Rhinolo-
phidae, their eyes are
generally large and the
tragus is well developed,
maintaining almost the
same form throughout
the species, however
much the other parts
of the body may vary
.
(Mormops blainvillei)
.
From Dobson. colour, and the face and
back are often marked
with white streaks
.
A few species, probably all those with the
tail and interfemoral membrane well developed, feed principally
on insects, while the greater number of the species of the See also:groups
Vampyreae and Glossophageae appear to live on a mixed See also:diet
of insects and fruits, and the Desmodonteae, of which two species
are known, are true blood-suckers, and have their teeth and intestinal
See also:tract specially modified in accordance with their habits
.
The group
is practically limited to the tropical and subtropical parts of Central
and South See also:America, although one species of Otopterus reaches See also:Cali-
nosrtils open by simple apertures at the extremity of the muzzle in front, not margined by a distinct nose-leaf; while, in See also:compensation the chin is furnished with expanded leaf-like appendages
.
The tad is short
.
It includes two genera
.
In Chilonycteris the See also:crown of the head is moderately elevated above the face-line, and the basi-See also:cranial See also:axis is almost in the same See also:plane as the facial, while in Mormops (fig. io) the crown of the head is greatly elevated above the face-line, and the basi-cranial axis is nearly at right angles to the facial; i
.
?, p
.
j,
in both genera
.
As regards the species of Chilonycteris, the most striking feature is the occurrence of a rufous and a dark See also: Here may be mentioned the two species of tropical American See also:hare-lipped bats, forming the genus Noctilio, which presents characters common to this and the following family, to which latter it is often referred . The typical N. leporinus is a bat of curious aspect, with strangely folded lips, erect skin-processes on the chin, and enormous feet and claws . The two middle incisors are close together, and so large as to conceal the small outer ones, while in the lower jaw there are but two small incisors; the premolars numbering '~ . These bats live near the See also:coast, and feed on small crabs and fishes . Most of the remaining members of the family are included in the subfamily Phyllostomatinae, characterized by the presence of a distinct nose-leaf and the warty chin . The clitoris is imperforate, whereas it is perforated in the Mormopsinae . The incisors are generally f (occasionally 1), and the molars well developed . The sub-family is divided into a number of groups or sections . The first of them, the Vampyreae, is characterized as follows: Muzzle long and narrow in front, the distance between the eyes generally less than (rarely equal to) that from the See also:eye to the extremity of the muzzle; nose-leaf horseshoe-shaped in front, lanceolate behind; interfemoral membrane well developed ; tail generally distinct, rarely absent; inner margin of the lips not fringed; i . " or p. f or 3; molars with W-shaped cusps, usually well developed . Nearly all the Vampyreae appear to be insectivorous, so that the See also:term cannot be considered indicative of habits; but a few, if not all, probably supplement their insect-diet with fruit . Vampyrus spectrum (the largest bat in the New World) is said to be wholly frugivorous, and Otopterus waterhousei appears to prey occasionally on smaller bats . The genera may be arranged in two subgroups ac-cording as the tail is produced to the margin of the interfemoral membrane or perforates it to appear on its upper surface . In the first See also:division are included three genera, Lonchorhina, Otopterus (or Macrotus) and Dolichophyllum (orMacrophyllum), the first represented by L. aurita, characterized by an extraordinary long nose-leaf, and peculiarly large ears and tragus . In the second subsection are included Vampyrus, Chrotopterus, Tonatia (Lophostoma) Micronycteris, Glyphonycteris, Trachyops, Phylloderma, Phyllostoma, Anthorhina (Tylostoma), Minton, Hemiderma (Carollia) and Rhinophylla ; all, with the exception of the last, distinguished chiefly by the form of the skull and the presence or absence of the second lower premolar . Phyllostoma hastatum, next in point of size to Vampyrus spectrum, is a well-known species in South America; P. elongatum (fig. ii) differs in its smaller size and larger nose-leaf . Hemiderma brevicauda, a small species, closely resembles Glossophaga soricina, and forms a connecting See also:link between this and the next group . Rhinophyllapumilio is the smallest species of the family; further distinguished by the absence of a tail, the narrowness of its molars, which do not form W-shaped cusps, and the small size of the last upper molar, characters connecting it and the group with the Stenodermateae . Both in Hemiderma and Rhinophylla the zygomatic arch is incomplete . The next subsection, Glossophageae, presents the following distinctive features: Muzzle long and narrow; tongue long and extensible, attenuated towards the tip, and beset with long filiform recurved papillae; lower lip with a wide groove above, and in front margined by small warts; nose-leaf small; tail short or none; i. f, p. or } or I, m. or f or I; teeth narrow; molars with narrow W-shaped cusps, sometimes indistinct or absent; lower incisors small or See also:deciduous . The species included in this group represent some ten genera, distinguished principally by differences in the form and number of the teeth, and the presence or absence of the zygomatic . arch of the skull . In Glossophaga and Phyllonycteris the upper incisors form a continuous row between the canines . In Mono phyllusand Leptonycteris (Ischnoglossa) they are separated into pairs by a narrow See also:interval in front; while in Lonchoglossa, Glossonycteris and Choeronycteris they are widely separated and placed in pairs near the canines . In the first four of these genera the lower incisors are present (at least to a certain See also:age), in the last three they are deciduous even in youth . The zygomatic arch is wanting in Phyllonycteris, Glossonycteris and Choeronycteris . The typical species is Glossophaga sorieina, which, as already mentioned, closely resembles Hemiderma upper incisors, separated by gaps from the canines, and from one another in the middle line . The distinctive feature of these bats is the free tail-tip, which pierces the interfemoral membrane to appear on its upper surface, and may project beyond its margin . As a rule, these bats may also be recognized by the peculiar form of the muzzle, which is obliquely truncated, the nostrils projecting more or less in front beyond the lower lip, by the first phalange of the middle finger being folded in repose forwards on the upper surface of the metacarpal bone, and by the upper incisors . Although See also:cosmopolitan, these bats rarely extend north or south of the thirtieth See also:parallels of See also:latitude . The family may be divided into two subfamilies, of which the Emballonurinae is 'characterized by the incomplete premaxillae, the presence of only one phalange in the index finger, and the short tail . The dental formula is generally i. s (sometimes 4 or 4), c . , p . 4, m . . This subfamily may be further subdivided into subgroups or sections of which the first, Embalionurae, is characterized by the slender tail perforating the interfemoral membrane, so as to appear on its upper surface; the legs long, with a slender fibula; the incisors weak; and the pre-molars 4 . The typical genus Emballonura presents the following features: i . extremity of the muzzle more or Iess produced beyond the lower lip, forehead FIG . 14 . — Ear of See also:flat . The genus contains several species, Emballonura raffrayana. inhabiting islands from Madagascar From Dobson. through the Malay Archipelago and Siam to the Navigator Islands . Coleiira, with i . 4, the extremity of the muzzle broad, and the forehead See also:concave, has two species from East Africa and the Seychelles . Rhynchonycteris is distinguished from Coledira by the produced extremity of the muzzle . The single species, R. ease, from Central and South America, is common in the vicinity of streams, where it is usually found during the See also:day resting on the See also:vertical faces of rocks, or on trunks of trees growing over See also:water; it escapes See also:notice owing to the greyish colour of the fur of the body and of small tufts on the antebrachial membrane See also:counterfeiting the weathered surfaces of rocks and bark . As evening approaches it appears on the wing, flying close to the water . Saccopteryx has i . 4, and the antibrachial membrane with a pouch opening on its upper surface; it contains several species from Central and South America . This sac is developed only in the male and in the female is rudimentary . In adult males a valvular longitudinal opening occupies the upper surface of the membrane leading into a small pouch, the interior of which is lined with a glandular membrane secreting an unctuous reddish substance with a strong ammoniacal odour . Allied genera are the tropical American Peropteryx and the Brazilian Cormier !. The various species of See also:tomb-bats (Taphozous) inhabit the tropical and subtropical parts of all the eastern hemisphere except Polynesia, and are distinguished by the cartilaginous p |