Part 53

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._ 2/2, _p._ 2/3 or 3/3 or 2/2, _m._ 3/3 or 2/3 or 2/2; teeth narrow; molars with narrow W-shaped cusps, sometimes indistinct or absent; lower incisors small or 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 _Monophyllus_ and _Leptonycteris_ (_Ischnoglossa_) they are separated into pairs by a narrow 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 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 soricina_, which, as already mentioned, closely resembles _Hemiderma brevicauda_, both in form and dentition. Its long brush-tipped tongue (which it possesses in common with other species of the group) is used to lick out the pulpy contents of fruits having hard rinds. The food of the species of this group appears to consist of both fruit and insects, and the long tongue may be used for extracting the latter from the deep corollas of flowers. Other genera are _Lonchophylla_, _Rhithronycteris_, _Hylonycteris_ and _Lychonycteris_, each with a single species (in 1904).

The third group, _Stenodermateae_, presents the following characteristics:--Muzzle very short and generally broad in front, the distance between the eyes nearly always exceeding (rarely equalling) the distance from the eye to the extremity of the muzzle; nose-leaf short, horseshoe-shaped in front, lanceolate behind (except in _Brachyphylla_ and _Centurio_); interfemoral membrane concave behind; tail none; inner margin of the lips fringed with conical papillae; _i._ 2/2 or 2/1, _p._ 2/2, _m._ 3/3 or 2/3 or 2/2; cheek-teeth broad (except in _Sturnira_), molars with concave or flat crowns margined externally by raised cutting-edges. Although the _Stenodermateae_ are generally easily distinguished from the _Vampyreae_ by the shortness and breadth of the muzzle and the form of the cheek-teeth, certain species of the latter resemble the former in external appearance, agreeing almost absolutely in the form of the nose-leaf, the ears and the tragus, and the warts on the chin. These resemblances show that, while the form of the teeth and jaws has become modified to suit the food, the external characters have remained much the same, and indicate the common origin of the two sections. The food of these bats appears to be wholly or in great part fruit. The species are divided into some eleven genera, mostly distinguished by the form of the skull and teeth. _Artibeus_ includes the frugivorous _A. perspicillatus_. _Stenoderma achradophilum_, found in Jamaica and Cuba, with the last, from which it is scarcely distinguishable externally except by its much smaller size, differs in the absence of the horizontal plate of the premaxillae on the palate. _Sturnira lilium_, while agreeing with these in the form of the nose-leaf and ears, differs from all the species of the family in its longitudinally-grooved molars, which resemble those of the _Pteropodidae_ more closely than those of any other bats; and the presence of tufts of long differently-coloured hairs over glands in the sides of the neck is another character in common with that group. _Centurio senex_ (fig. 13) is the type of a small genus distinguished from _Stenoderma_ and other genera of this group by the absence of a distinct nose-leaf. Some naturalists make this genus the type of a distinct subgroup, _Centurioneae_. Up to 1904 the genera, exclusive of _Centurio_, included in the _Stenodermateae_ were _Artibeus_ (with several sub-genera), _Vampyrops_ (also with subgenera), _Mesophylla_, _Chiroderma_, _Stenoderma_ (with 3 subgenera), _Ectophylla_, _Ametrida_ (with 2 sub-genera), _Pygoderma_, _Sturnira_ and _Brachyphylla_.

The third subfamily, _Desmodontieae_, is represented only by the blood-sucking bats, and distinguished by having _i._ ½, of which the upper pair are cutting, the rudimentary molars, the very short interfemoral membrane, and the blood-sucking habit. They are further characterized as follows: Muzzle short and conical; nose-leaf distinct; _p._ 2/3, _m._ 1/1 or 0/0; upper incisors occupying the whole space between the canines; premolars narrow, with sharp-edged longitudinal crowns; molars rudimentary or absent; stomach elongated, and intestiniform. There are two genera, _Desmodus_, without calcar or molars, and _Diphylla_, with a short calcar and a single rudimentary molar on each side--restricted to Central and South America. _Desmodus rufus_, the commoner species, is a little larger than the noctule bat, and abundant in certain parts of South America, where it is troublesome owing to its attacks upon domestic animals, sucking their blood and leaving them weakened from repeated bleedings. (See VAMPIRE.)

Free-tailed bats.

The fourth family of bats, unlike any of the three previous ones, has a cosmopolitan distribution. These free-tailed bats, as they are conveniently called, constituting the family _Emballonuridae_, present the following distinctive features. The nostrils are of normal form and without a nose-leaf. The premaxillae have their palatal portion imperfectly developed, and united by a slender process with the maxillae. The ears are large, with a small tragus. The middle finger has two phalanges, and the index generally a single one. The fibula is incomplete. The tail is generally short, and always partly free from the interfemoral membrane. There is generally only a single pair of 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 cosmopolitan, these bats rarely extend north or south of the thirtieth parallels of 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._ 1/3 (sometimes 2/3 or 1/2), _c._ 1/1, _p._ 2/3, _m._ 3/3. 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 premolars 2/2. The typical genus _Emballonura_ presents the following features: _i._ 2/3, extremity of the muzzle more or less produced beyond the lower lip, forehead flat. The genus contains several species, inhabiting islands from Madagascar through the Malay Archipelago and Siam to the Navigator Islands. _Coleura_, with _i._ 1/3, the extremity of the muzzle broad, and the forehead concave, has two species from East Africa and the Seychelles. _Rhynchonycteris_ is distinguished from _Coleura_ by the produced extremity of the muzzle. The single species, _R. naso_, from Central and South America, is common in the vicinity of streams, where it is usually found during the day resting on the vertical faces of rocks, or on trunks of trees growing over water; it escapes notice owing to the greyish colour of the fur of the body and of small tufts on the antebrachial membrane counterfeiting the weathered surfaces of rocks and bark. As evening approaches it appears on the wing, flying close to the water. _Saccopteryx_ has _i._ 1/3 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 _Cormura_. The various species of tomb-bats (_Taphozous_) inhabit the tropical and subtropical parts of all the eastern hemisphere except Polynesia, and are distinguished by the cartilaginous premaxillaries, the deciduous pair of upper incisors, and the presence of only two pairs of lower incisors. Most of the species have a glandular sac (fig. 15) between the angles of the lower jaw, more developed in males than in females, in some species absent in the latter. An open throat-sac is wanting in _T. melanopogon_, but about its position are the openings of small pores, the secretion from which probably causes the hairs to grow long, forming the black beard found in many males. The three tropical American white bats, _Diclidurus_, with _i._ 1/3, _c._ 1/1, _p._ 3/2, _m._ 3/3, resemble _Taphozous_ in the form of the head and ears, but, besides other characters, differ from all other bats in possessing a pouch, opening off the centre of the interior surface of the interfemoral membrane; the extremity of the tail enters this, and perforates its base.

The second subfamily of the _Emballonuridae_, _Rhinopomatinae_, is represented only by the genus _Rhinopoma_, with several species ranging from Egypt through Arabia to India, Burma and Sumatra. The premaxillae (fig. 16) are complete; the index finger has two phalanges; the tail is very long and mouselike; and the dental formula _i._ 1/2, _c._ 1/1, _p._ 1/2, _m._ 2/3. Dr G.E. Dobson has remarked that these mouse-tailed bats might be elevated to the rank of a family, for it is difficult to determine their affinities, a kind of cross relationship attaching them to the _Nycteridae_ on the one hand and to the _Emballonuridae_ on the other. These bats, distinguished from all other Microchiroptera by the presence of two phalanges in the index finger and the long and slender tail projecting far beyond the narrow interfemoral membrane, inhabit the subterranean tombs in Egypt and deserted buildings generally from north-east Africa to Burma and Sumatra.

Typical bats.

The last group, according to the system adopted by Prof. Max Weber, is that of the _Vespertilionidae_, which includes such typical bats as the pipistrelle, the noctule, and the long-eared species. By Mr G.S. Miller[1] the first section of the family--_Natalinae_--is regarded as of family rank, while the last section, or _Molossinae_, is included by Dr G.E. Dobson in the _Emballonuridae_, from the typical forms of which its members differ widely in tail-structure. In this extended sense the family, which has a cosmopolitan distribution, may be defined as follows:--The nostrils are normal and without a nose-leaf. The ethmoturbinal bones of the nasal chamber are involuted. The palatine processes of the premaxillae do not form a suture. The ear is mostly large, with a tragus. The middle finger (except in _Thyroptera_) has two phalanges. The fibula is usually rudimentary. The tail is long and does not perforate the interfemoral membrane. The incisors are generally 2/3 or 1/2, but may be reduced to 1/1 in the _Molossinae_.

In the first subfamily, _Natalinae_, which is exclusively tropical American, the other upper incisors are separated from one another and from the canines; palatine processes of the premaxillae are at least partially developed; and the dental formula is _i._ 2/3, _c._ 1/1, _p._ {2 or 3}/3, _m._ 3/3. In general appearance these bats recall the more typical _Vespertilionidae_, although the form of the muzzle is suggestive of the _Mormopsinae_ among the _Phyllostomatidae_. Again, while the form of the skull is vespertilione, the relation of the vomer to the front end of the premaxillae is of the phyllostomine type. The molars and incisors are likewise vespertilione, whereas the premolars are as distinctly phyllostomine. Finally, while the third, or middle, finger normally has two phalanges, as in typical _Vespertilionidae_, the second of these is elongated and in _Thyroptera_ divided into two, as in _Phyllostomatidae_.

The first two genera, _Furipterus_ and _Amorphochilus_, each have a single species, the latter being distinguished from the former by the wide separation of the nostrils and the backward prolongation of the palate. In both the crown of the head is elevated, the thumb and first phalange of the middle finger are very short, and the premolars are 2/3. The same elevation of the crown characterizes the genera _Natalus_ and _Chilonatalus_ (fig. 17), in which the premolars are 3/3: in general appearance these bats are very like the Old World vespertilionine genus _Cerivoula_, except for the short triangular tragus. Lastly, _Thyroptera_ includes two species distinguished by an additional phalange in the middle finger and by accessory clinging-organs attached to the extremities. In _Thyroptera tricolor_, _i._ 2/3, _p._ 3/3, from Brazil, these have the appearance of small, circular, stalked, hollow disks (fig. 18), resembling miniature sucking-cups of cuttle-fishes, and are attached to the inferior surfaces of the thumbs and the soles of the feet. By their aid the bat is able to maintain its hold when creeping over smooth vertical surfaces.

The second or typical subfamily, _Vespertilioninae_, includes all the remaining members of the family with the exception of the aberrant _Molossinae_. The upper incisors are in proximity to the canines; the premaxillae widely separated; the ears medium or large; the dental formula is _i._ 2/3 (or 1/3), _c._ 1/1, _p._ 3/3 (2/3, 2/2, or 1/2), _m._ 3/3; and the fibula very small and imperfect. All the members of this large cosmopolitan group are closely allied, and differ chiefly by external characters. They may be divided into subgroups. In the first of these, the _Plecoteae_, of which the long-eared bat (_Plecotus auritus_) is the type, the crown of the head is but slightly raised above the face-line, the upper incisors are close to the canines, and the nostrils are margined behind by grooves an the upper surface of the muzzle, or by rudimentary nose-leaves; the ears being generally very large and united. Of the six genera, _Plecotus_, with _i._ 2/3, _p._ 2/3, has three species:--one the long-eared European bat referred to above; _P. macrotis_, restricted to North America, is distinguished by the great size of the glandular prominences of the sides of the muzzle, which meet in the centre above and behind the nostrils; the third species being also American. The second, _Barbastella_, with _i._ 2/3, _p._ 2/2, distinguished by its dentition and by the outer margin of the ear being carried forwards above the mouth and in front of the eye, includes the European barbastelle bat, _B. barbastellus_, and _B. darjelingensis_ from the Himalaya. _Otonycteris_, _i._ 1/3, _pm._, 1/2, connecting this group with the _Vespertilioneae_, is represented by _O. hemprichii_, from North Africa and the Himalaya, and an Arabian species. The next two genera are distinguished by the presence of a rudimentary nose-leaf: _Nyctophilus_, _i._ 1/3, _p._ 1/2, with three species from Australasia; and _Antrozous_, _i._ 1/2, _p._ 1/2, distinguished from all the other members of the subfamily by having but two lower incisors, and from other _Plecoteae_ by the separate ears; the two species inhabit California. The sixth genus, _Euderma_, is also represented by a Californian species.

The second group _Vespertilioneae_, with about thirteen genera, includes the great majority of the species; and a large number of these may be classed under _Vespertilio_, which is divisible into subgenera, differing from one another in the number of premolars, and often ranked as separate genera. One group is represented by _V._ (_Histiolus_) _magellanicus_, a species remarkable for its extreme southern range, its relatives being also South American. A second group, with _p._ 1/2, includes the British serotine, _V._ (_Eptesicus_) _serotinus_, of Europe and northern Asia, and represented in North America by the closely allied _V._ (_E._) _fuscus_. In the typical group, which includes the Old World _V. murinus_, one species, _V. borealis_, ranges to the Arctic circle. The European noctule, _V._ (_Pierygistes_) _noctula_, and Leisler's bat, _V._ (_P._) _leisleri_, represent another group; and the common pipistrelle, _V._ (_Pipistrellus_) _pipistrellus_, yet another, with _p._ 2/2. The only other group that need be mentioned is one represented by the North American _V._ (_Lasionycteris_) _noctivagans_, with _p._ 2/3. The African _Läephotes_, the Chinese _Ia_, and the Papuan _Philetor_ are allied genera, each with a single species. _Chalinolobus_ and _Glauconycteris_ have the same general dental character as _Vespertilio_, but are distinguished by the presence of a lobe projecting from the lower lip near the gape; the former, with _p._ 2/2, is represented by five Australasian species, one of which extends into New Zealand; while the latter, with _p._ 1/2, is African. The species of _Glauconycteris_ are noticeable for their peculiarly thin membranes traversed by distinct reticulations and parallel lines. _Scotophilus_, with _i._ 1/3, _p._ 1/2, includes several species, restricted to the tropical and subtropical regions of the eastern hemisphere, though widely distributed within these limits. These bats, though approaching certain species of _Vespertilio_ in many points, are distinguished by the single (in place of two) pair of unicuspidate upper incisors separated by a wide space and placed close to the canines, by the small transverse first lower premolar crushed in between the canine and second premolar, and, generally, by their conical, nearly naked, muzzles and thick leathery membranes. _S. temmincki_ is the commonest bat in India, and appears often before the sun has touched the horizon. _S. gigas_, from equatorial Africa, is the largest species. _Nycticejus_, with the same dental formula as _Scotophilus_, is distinguished, by the first lower premolar not being crushed in between the adjoining teeth, and the comparatively greater size of the last upper molar. It includes only the North American _N. humeralis_ (_crepuscularis_), a bat scarcely larger than the pipistrelle. The hairy-membraned bats of the genus _Lasiurus_ (_Atalapha_), with _i._ 1/3, _p._ 2/2 or 1/2, are also limited to the New World, and generally characterized by the interfemoral membrane being more or less covered with hair and by the peculiar form of the tragus, which is expanded above and abruptly curved inwards. In those species which have two upper premolars the first is extremely small and internal to the tooth-row. The genus, which is divided into _Lasiurus_ proper and _Dasypterus_, is further characterized by the presence of four teats in the female, and by the general production of three or four offspring at a birth. _Rhogëessa_ and _Tomopeas_ are allied tropical American types. _Murina_, with the subgenus _Harpiocephalus_, has _i._ 2/3, _p._ 2/2, and includes several small bats distinguished by the prominent tube-like nostrils and hairy interfemoral membrane. _M. suilla_, from Java, the Malay and neighbouring islands, is a well-known species, and the closely allied _M. hilgendorfi_ is from Japan. The remaining species are from the Himalaya, Tibet and Ceylon; and apparently restricted to the hill-tracts of the countries in which they are found. Next to _Vespertilio_ the genus _Myotis_ (divisible into several subgenera), with _i._ 2/3, _p._ 3/3, includes the largest number of species, and has rather a wider geographical distribution in both hemispheres, one species being recorded from the Navigator Islands. The species may be recognized by the peculiar character of the pairs of upper incisors on each side, the cusps of which diverge from each other, by the large number of premolars, of which the second upper is always small, and by the oval elongated ear and narrow tragus. The British _M. bechsteini_ and _M. nattereri_ are examples of this group. _Cerivoula_ (_Kerivoula_), which also has _p._ 3/3, is distinguished by the parallel upper incisors and the large second upper premolar. There are numerous African and Indo-Malayan species, of which _C. picta_, from India and Indo-Malay, is characterized by its brilliant orange fur, and membranes variegated with orange and black. The genus includes delicately formed insectivorous, tropical, forest-haunting bats, whose colouring approximates them to the ripe bananas among which they often pass the daytime.

Another subgroup, _Minioptereae_, is represented solely by the genus _Miniopterus_, with _i._ 2/3, _p._ 2/3. The incisors are separated from one another in front and from the canines; the first phalange of the middle finger is very short, the crown of the head elevated, and the tail long. The genus is represented by some half-dozen Old World species, among which the typical _M. schreibersi_ ranges from Europe, southern Asia, and Africa to Japan and Australasia.