Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/433

Rh CHlKOi TEilA.] MAMMALIA well-defined lobe projecting near the angle of the mouth from the lower lip, and by the unicuspidate upper inner incisors. The species fall into two subgenera : Chalinolobus, pm |, with C. tubcr- culatus from New Zealand, Tasmania, and Australia, and three other species from Australia ; and Glauconydcris, pm, limited to southern and equatorial Africa, with G. argentatus and two other species, the Bats of this subgenus being especially remarkable for their peculiarly thin membranes traversed by very distinct reticulations and parallel lines. Scotophilus, i I, pm |, includes eight species, restricted to the tropical and subtropical regions of the eastern hemisphere, though widely distributed within these limits. The Bats of this genus, though difficult to deline, and approaching certain of those of Vcspcrugo in many points, are distinguished espe cially by the single pair of unicuspidate upper incisors separated by a wide space and placed close to the canines, by the Fl( . 71 _ Ik . ad of small transverse first lower premolar emaryinatuf. Dobson, Mo- crushed in between the canine and &quot;&amp;lt;&amp;gt;ffr. Asiat. Chiropt. second premolar, and, generally, by their conical nearly naked muzzles and remarkably thick leathery membranes. Sc. t&m- minckii is probably the commonest species of Bat in India, and appears often on the wing even before the sun has touched the horizon, especially when the white ants are swarming, feeding eagerly upon them as they rise in the air. Sc. gigas, from equa torial Africa, with the forearm 3 4 inches, is by far tha largest species. Xycticcjus, with the same dental formula as ScotopJiilus, is distin guished by the first lower premolar not being crushed in between the adjoining teeth, and by the comparatively much greater size of the last upper molar. It includes only the common North American species N. crepuscular is, a small Bat scarcely larger than the Pipistrelle. Atalapha, i -g-, pm or {, with five species, is also limited to the New &quot;World. The Bats of this genus are generally characterized by the interfemoral membrane being more or less covered with hair (in the two commonest species, A, novcboracensis and A. cincrca, wholly thickly covered), and by the peculiar form of the tragus, which is expanded above and abruptly curved inwards. In these species, which have two upper premolars, the first is extremely small and quite internal to the tooth-row. The genus Harpyioccphalus, i -, pm -f, includes eight very remarkable small species, distinguished at once by their prominent tube-like nostrils and hairy interfemoral membrane. //. suillus from Java and neighbouring islands is the best-known species, and another closely allied, //. hilgendorfi, has been described by Professor Peters from Japan. The remaining six species are known only from the Himalaya and Tibet. All appear to be restricted to the hill tracts of the countries in which they are found. Next to Vesperugo, the genus Vespertilio, i f, pm f, includes by far the largest number of species, amounting to forty-three ; it has, however, rather a wider geographical distribution in both hemispheres, one species at least being recorded from the Navigators Islands. The species are easily 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 very small, and by the oval elongated ear and narrow attenuated tragus. Kerivoula, with the same dental formula as Vespertilio, is easily distinguished by the parallel upper incisors, and by the compara tively large size of the second upper premolar. Ten species have been FIG. 72. Side and Front View of the Head of Keri- described from the l ollla ftarduictii. Dobson, Mono&amp;lt;jr. Asiat. Chiropt. Ethiopian and Oriental regions, of which K. picta, from India and the Indo-Malayan subregion, is the best-known, being well char acterized by its brilliantly coloured orange fur and conspicuously marked membrane, which are variegated with orange and black. The genus includes the most delicately formed and most truly insectivorous, tropical, forest-haunting Bats, which appear to stand as regards the species of Vespertilio in. a position similar to that occupied by Chalinolobus with respect to Vesperugo. The next group, Miniopteri, includes two genera, Natalus and Minio})terus, characterized by the great elevation of the crown of the head above the face-line, and by the upper incisors being separated from the canines and also in front. Natalus, with the same dental formula and general external form as Kerivoula, is distinguished by the short triangular tragus, and by the characters of the group enumerated above. It includes three species, all restricted to South and Central America and the West Indies ; the head of one, N. micropus, lately described by the present writer, is shown in fig. 73. Miniopterus, i f, pm f, at once distinguished by the shortness of the first phalanx of the middle finger, and by the great length of the tail, which is wholly contained within the interfemoral membrane, includes four species, restricted to the eastern hemi sphere. Of these the best-known, M. schreibcrsii, is very widely distributed, being found almost everywhere through out the tropical and warmer temperate regions of the eastern hemisphere, speci mens from Germany, Mada gascar, Japan, and Australia differing in no appreciable respect. The last group, Thy- ropteri, includes also two genera, distinguished not only by the presence of an FIG. 73. Head of NataHw micrrpus. x 2. additional osseous phalanx Dobson, Proc. Zo,&amp;gt;l. Hoc., 1880. in the middle finger and an equal number of phalanges in the toes, but also by peculiar accessory clinging organs attached to the extremities. In Thyroptcra tricolor, if, pm f, from Brazil, these organs have the appearance of small, circular, pedunculatcd, hollow disks (fig. 74), resembling in miniature the sucking cups of cuttle-fishes, and attached to the inferior surfaces of the thumbs and soles of the feet, with which the animal is enabled to main tain its hold when creeping over smooth vertical surfaces (for an FIG. 74. Suctorial Disks in Thyroptcra tricolor, a, side, and b, concave surface, of thumb disk ; c, foot with disk, and calcar with projections (all much en larged). Dobson, Proc. Zoo . Soc., 1876. account of the minute anatomy of these clinging organs see the writer s paper in the Proc. Zool. Soc., 1876, pp. 531-34). In Myxopoda aurita from Madagascar (type of the second genus), with the same dental formula, but differing much in the characters of the teeth and in the form of the ears, the whole inferior surface of the thumb supports a large sessile horse-shoe-shaped adhesive pad, with the circular margin directed forwards and notched along its edge, and a smaller pad occupies part of the sole of the foot. Family NYCTEUID.E. This small family, defined in the synopsis above, includes only FIG. 15.Mcgaderma yigas. x f Dobson, Proc. Zool. Soc., 1880. two genera of Bats of very peculiar aspect, limited to the tropical and subtropical parts of the eastern hemisphere.