Chapter 52

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._ 2/2 (or ½), _c._ 1/1, _p._ 2/3, _m._ ½. 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 Africa south of the Sahara, and are distinguished by the large and long head, expansible and often folded lips, and the white tufts of hair on the margins of the ears. The males are provided with glandular pouches, situated in the skin of the side of the neck near the point of the shoulder, which are rudimentary or absent in females. 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 figs, the juicy contents of which their voluminous lips and capacious mouths enable them to swallow without loss. The huge and ugly West African 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 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._ 2/2, _c._ 1/1, _p._ 3/3, _m._ 2/3. All are of large size, and the absence of a tail, the long pointed muzzle, and the woolly fur covering the neck render their recognition easy. One of the species, _P. edulis_, inhabiting Java, measures 5 ft. across the fully extended wings, and is the largest member of the order.

The range of the genus extends from Madagascar through the Seychelles to India, Ceylon, Burma, the Malay Archipelago, Japan, New Guinea, Australia and Polynesia. Although two species inhabit the Comoro Islands, scarcely 200 m. from the mainland, not one is found in Africa; while the common Indian species is closely allied to the Madagascar flying-fox. The Malay Archipelago and Australia form the headquarters of these bats, which in some places occur in countless multitudes. The colonies exhale a strong musky odour, and when awake the occupants utter a loud incessant chatter. Wallace's fruit-bat of Celebes and Macassar has been made the type of a separate genus, as _Styloctenium wallacei_. In _Roussettus_ (or _Cynonycteris_) the dentition is as in _Pteropus_, but the tail is short, and the fur of the nape of the neck not different from that of the back: its distribution accords with that of _Pteropus_, except that it includes Africa and does not reach farther east than New Ireland. _R. aegyptiacus_ inhabits the chambers of the Great Pyramid and other deserted buildings in Egypt, and is probably the species figured in Egyptian frescoes. _Boneia_, with two species, from Celebes, differs in having only two upper incisors. _Harpyionycteris_ and _Scotonycteris_, respectively from the Philippines and West Africa, are represented by a single species each; but of _Cynopterus_, which is mainly confined to the Indo-Malay countries, there are some half-score different kinds. The dentition is _i._ 2/[2 or 1], _c._ 1/1, _p._ 3/3, _m._ 3/3, the muzzle is shorter than in _Roussettus_, with the upper 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 banana twice its own weight in three hours. Among several Austro-Malay genera, such as _Ptenochirus_ and _Balionycteris_, the tube-nosed bats of the genus _Gelasinus_ (or _Harpyia_) are remarkable for the conformation of the nostrils (fig. 5). _Cephalotes_, with one species, ranging from Celebes to the Solomon group, has the dentition _i._ 1/1, _c._ 1/1, _p._ 2/3, _m._ 2/3, premaxillae not united in front, nostrils simple, muzzle short, index finger without a claw, tail short. As in _Gelasinus_, the wing-membrane arises from the middle line of the back, to which it is attached by a longitudinal thin process of skin; the wings are 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 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 gum, and the 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 Fiji, New Guinea and the New Hebrides, is distinguished from other bats of this family by the length of its tail, which is nearly as long as the forearm. The dentition is _i._ 2/1, _c._ 1/1, _p._ 2/3, _m._ 2/2, while the index finger has no claw, and the wings arise from the spine. _Eonycteris_, with the dentition _i._ 2/2, _c._ 1/1, _p._ 3/3, _m._ 2/3, is also represented by a single species, _E. spelaea_, from Tenasserim, Burma, and the Malay Peninsula and Islands, which has somewhat the 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. _Carponycteris_ (_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. minimus_ is the smallest known species of the suborder, much smaller than the serotine bat of 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 Himalaya. _Callinycteris_ of Celebes, with the dentition _i._ 2/2, _c._ 1/1, _p._ 2/2, _m._ 3/3, has a short tail and no index-claws, while _Nesonycteris_ of the Solomons, with the dentition _i._ 2/1, _c._ 1/1, _p._ 3/3, _m._ 3/3, differs by the absence of the tail.

_Microchiroptera._

Insect-eating bats.

The second and larger suborder, the Microchiroptera, includes all the insectivorous species, the majority of which are of relatively small size as compared with the Megachiroptera. In these bats, with a few specialized exceptions, the crowns of the cheek-teeth are surmounted by 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 interiorly 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 prey. From the observations of C. 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 moth, and bends up the tail so as to form a receptacle for the insect as it drops.

In the _Rhinolophidae_, Horse-shoe and Leaf-nosed bats of the Old 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 laterally. 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 differences in their form afford characters in the discrimination of the species, which resemble one another closely in dentition and the colour of the fur.

In the first subfamily, _Rhinolophinae_, the first toe has two, and the other 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. 1/2, c. 1/1, p. 2/3, m. 3/8, 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 inhabits elevated hill-tracts in India and Malaysia; _R. hipposiderus_ of Europe, extending into south England and Ireland, is one of the smallest; and _R. ferrum-equinum_ represents the average size of the species, which are mainly distinguished from one another by the form of the nose-leaf. The last-named species extends from England to Japan, and southward to the Cape of Good Hope, but is represented by a number of local races. When sleeping, the horseshoe bats, at least in some instances, suspend themselves head downwards, with the wings wrapped round the body after the manner of fruit bats. The posture of ordinary bats is quite different, and while the lesser horseshoe (_R. hipposiderus_) alights from the air in an inverted position, other bats, on first coming to rest, do so with the head upwards, and then reverse their position.

In the second subfamily, _Hippo-siderinae_ (formerly called _Phyllorhinae_), the toes are equal and include two phalanges each, while the ilio-pectineal spine is united by a bony isthmus with a process derived from the antero-inferior surface of the ilium. _Hipposiderus, Clöeotis, Rhinonycteris, Triaenops, Anthops_ and _Coelops_ represent this subfamily. _Hipposiderus_ (_Phyllorhina_), with many species, ranging over Asia, Africa and Australasia, and the dental formula i. 1/2, c. 1/1, p. 2/2, or 1/2, m. 3/3, 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 Amoy in China, and in the Himalaya at an elevation of 5500 ft. Many are provided with a frontal sac behind the nose-leaf, rudimentary in females (see fig. 7), which can be everted at pleasure; the sides of this sac secrete a waxy substance, and its extremity supports a tuft of straight hairs. _Rhinonycteris_, represented by _R. aurantia_ from Australia, and _Triaenops_. by _T. persicus_ from Persia and other species from Africa and Madagascar, are closely allied genera. _Triaenops_ (fig. 8) is characterized by the remarkable form of its nasal appendages and ears, and the presence of a bony projection from the upper extremity of the second phalange of the fourth finger. _Coelops_ (_C. Frithi_), from the Bengal Sanderbans, Java and Siam is distinguished by the peculiar form of its nose-leaf and the length of the metacarpal bone of the index finger, as well as by the shortness of the calcar and interfemoral membrane. _Clöeotis_ 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 face.

False vampires.

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 Weber as a subfamily under the name of _Myadermatinae_. It differs by the presence of a small tragus in 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 premaxillae and upper incisors (i. 0/2, p. (2 or 1)/2), 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. gigas_ (fig. 9), from central Queensland, is the largest species of the genus, and of the suborder. _M. lyra_, common in India (fore-arm 2.7 in.), has been caught in the 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 common to Africa and the Malay Peninsula and Islands, has ossified premaxillae and upper incisors (_i._ 2/3, _p._ 1/2), 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 lower jaw also projects; but, instead of a nose-leaf, the face is marked by a deep longitudinal sharp-edged groove extending from the nostrils to the band connecting the base of the large ears; the sides of this depression being margined as far back as the eyes by small horizontal cutaneous appendages. With the exception of _N. javanica_, the species are limited to Africa.

Vampires.

According to the classification followed by Dr G.E. Dobson, the extensive family of New World bats known as _Phyllostomatidae_ was widely sundered from the two preceding groups; but in Prof. Max Weber's system they are placed next one another--an arrangement which has the great 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 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 denning the boundaries of distinct palatine foramina (in place of being rudimentary, as in _Nycteridae_ and _Rhinolophidae_). 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 or short. Generally the dentition is _i._ 2/2, _c._ 1/1, _p._ 2/3, _m._ 3/3.

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 incisors, or with both. Unlike the _Rhinolophidae_, 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. Their fur is of a dull 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 groups _Vampyreae_ and _Glossophageae_ appear to live on a mixed diet of insects and fruits, and the _Desmodonteae_, of which two species are known, are true blood-suckers, and have their teeth and intestinal tract specially modified in accordance with their habits. The group is practically limited to the tropical and subtropical parts of Central and South America, although one species of _Otopterus_ reaches California. In the first subfamily, _Mormopsinae_ (_Lobostominae_), the nostrils open by simple apertures at the extremity of the muzzle in front, not margined by a distinct nose-leaf; while, in compensation, the chin is furnished with expanded leaf-like appendages. The tail is short. It includes two genera. In _Chilonycteris_ the crown of the head is moderately elevated above the face-line, and the basi-cranial axis is almost in the same plane as the facial, while in _Mormops_ (fig. 10) 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._ 2/2, _p._ 2/3, in both genera. As regards the species of _Chilonycteris_, the most striking feature is the occurrence of a rufous and a dark brown phase in each. In some the two phases are very marked, but in others they are connected by intermediate shades. Here may be mentioned the two species of tropical American 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 1/2. These bats live near the 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 2/2 (occasionally 2/1), and the molars well developed. The subfamily 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 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._ 2/2 or 2/1, _p._ 2/2 or 2/3; molars with W-shaped cusps, usually well developed.

Nearly all the _Vampyreae_ appear to be insectivorous, so that the 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 according as the tail is produced to the margin of the interfemoral membrane or perforates it to appear on its upper surface. In the first division are included three genera, _Lonchorhina_, _Otopterus_ (or _Macrotus_) and _Dolichophyllum_ (or _Macrophyllum_), 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_), _Mimon_, _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. 11) differs in its smaller size and larger nose-leaf. _Hemiderma brevicauda_, a small species, closely resembles _Glossophaga soricina_, and forms a connecting link between this and the next group. _Rhinophylla pumilio_ 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.