especially when the white-ants are swarming, feeding eagerly upon them as they rise in the air. S. gigas, from Equatorial Africa, with the forearm measuring 3-4 inches, is by far the largest species. S. albofuscus, from the Gambia, which is readily distinguished from the other species by its white wings, is an aberrant form, in which the lower premolars are long and not crowded together, and thereby so closely resembles Vesperugo (Scotozous) dormeri as to render it almost impossible to distinguish Scotophilus and Vesperugo. The figured species is from India.

Nycticejus.-This genus, with the same dental formula as Scotophilus, is distinguished by the first lower premolar not being squeezed in between the adjoining teeth, and by the comparatively much greater size of the last upper molar. It includes only the common North American N. humeralis (crepuscularis), a small Bat scarcely larger than the Pipistrelle. It seems, however, as pointed out by Mr. O. Thomas, that the discovery of Scotophilus albofuscus renders the generic distinctness of Nycticejus no longer tenable, and that the species should be known as Scotophilus humeralis.

Atalapha.2-Dentition: i, c, p2, m ; total 32 or 30. The five species of this genus, which are confined to the New World, are generally characterised by the interfemoral membrane being more or less covered with hair (in the two commonest species, A. noveboracensis and A. cinerea, wholly covered), and by the peculiar form of the tragus, which is expanded above and abruptly curved inwards. These species have two upper premolars, of which the first is extremely small and quite internal to the tooth-row.

Harpyiocephalus.3-Dentition: i, c, 1, p, m; total 34. This genus includes some eight species of small Bats distinguished by their prominent tube-like nostrils and hairy interfemoral membrane. H. suillus, from Java and neighbouring islands, is the best-known species, and another closely allied (H. 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.

Vespertilio.-Dentition: i, ci, p, m; total 38. Next to Vesperugo, this genus includes by far the largest number of species, amounting to over forty; 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 recognised by the peculiar character of the upper incisors, the crowns of which diverge from each other; by the large number of premolars, of which the second upper one is always very small;

3

1 Rafinesque, Journ. de Physique, vol. lxxxviii. p. 417 (1819). Précis des Decouvértes et Trav. Somiol. p. 12 (1814). Hist. vol. x. p. 259 (1842)

2 Rafinesque,

Gray, Ann. Mag. Nat. Linn. Syst. Nat. 12th ed. vol. i. p. 46 (1766).

and by the oval elongated ear and narrow attenuated tragus. In the British Isles this genus is represented by four species, viz. Bechstein's Bat (V. bechsteini); the Reddish-Gray Bat (V. nattereri), of very local occurrence; Daubenton's Bat (V. daubentoni); and the Whiskered Bat (V. mystacinus).

Cerivoula. This genus, which has the same dental formula as Vespertilio, is distinguished by the parallel upper incisors,

FIG. 309.-Side and front views of the head of Cerivoula hardwickei. (Dobson, Monogr. Asiat. Chiropt.)

and the comparatively large size of the second upper premolar. Some ten species have been described from the Ethiopian and Oriental regions, of which C. picta, from India and the Indo-Malayan subregion, is the best-known, being well characterised by its brilliantly coloured orange fur and conspicuously marked membranes, which are variegated with orange and black. This 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 Miniopterine division includes only two genera, and is characterised by the great elevation of the crown of the head above the facial line, and by the upper incisors being separated from the canine and also in the middle line.

Natalus. This genus, while having the divisional characters mentioned above, agrees in the dental formula and its general external form with Cerivoula, from

which it is distinguished by the short triangular tragus. It includes three species, restricted to South and Central America and the West Indies; the head of N. micropus being shown in Fig. 310. Miniopterus.3-Dentition: i, c 1, p 3, m ; total 36. In addition to the difference in the number of the teeth, this genus is distinguished by the shortness of the first phalanx of the middle finger and the great length of the tail, which is wholly contained within the interfemoral membrane; it includes four species, restricted to the eastern hemisphere. Of

1 Gray, Ann. Mag. Nat. Hist. vol. x. p. 258 (1842), Kerivoula.

2 Gray, Mag. Zool. Bot. vol. ii. p. 496 (1838).

3 Bonaparte, Fauna Italica, fasc. xxi. (1837).

these the best-known, M. schreibersi, is very widely distributed, being found almost everywhere throughout the tropical and warmer temperate regions of the eastern hemisphere; specimens from Germany, Madagascar, Japan, and Australia differing in no appreciable respect from one another.

The last or Thyropterine division, which likewise comprises only two genera, is characterised by the presence of an additional osseous phalanx in the middle finger and an equal number of phalanges in the toes, and also by peculiar accessory clinging organs attached to the extremities.

Thyroptera.-Dentition: i, c, p 3, m; total 38. In the single species T. tricolor of Brazil the clinging organs have the appearance of small, circular, pedunculated, hollow discs (Fig. 311), resembling in miniature the sucking cups of cuttle-fishes, and are

FIG. 311.-Suctorial discs in Thyroptera tricolor. a, Side and b, concave surface, of thumbdisc; c, foot with disc, and calcar with projections (all much enlarged). Dobson, Proc. Zool. Soc. 1876.

attached to the inferior surfaces of the thumbs and soles of the feet. With these the animal is enabled to maintain its hold when creeping over smooth vertical surfaces.

Myxopoda.2-The second genus is likewise represented only by a single species-M. aurita of Madagascar-and is distinguished from the preceding by the characters of the teeth and the form of the ears. The whole inferior surface of the pollex 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.

Fossil Vespertilionide.-It is not improbable that Vesperugo is represented in the Upper Eocene of the Paris basin by V. parisiensis, which appears to be allied to V. serotina, although it has been regarded by some writers as generically distinct, under the name of Nyctitherium. Vesperugo (Nyctitherium) also occurs in the Bridger Eocene of the United States; Nyctilestes from the same

1 Spix, Sim. and Vesp. Bresil, p. 61 (1823).

2 A. Milne-Edwards, Bull. Soc. Philom. sér. 7, vol. ii. p. 1 (1878).

deposits being an allied extinct genus. A number of European Miocene species have been referred to Vespertilio, but the term in these cases must be used in a somewhat wide sense. Vespertiliarus, of the Phosphorites of Central France, differs from Vespertilio in the proportions of its premolars.

Section EMBALLONURINA.

Tail perforating the interfemoral membrane and appearing on its upper surface, or produced considerably beyond the truncated membrane; the middle pair of upper incisors generally large and close together.

Family EMBALLONURIDÆ.

First phalanx of the middle finger folded (in repose) on the dorsal surface of the metacarpal bone (except in Noctilio and Mystacops). Nostrils opening by simple circular or valvular apertures at the extremity of the muzzle, not surrounded or margined by foliaceous cutaneous appendages; tragus distinct.

The Emballonurida are generally easily distinguished 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 phalanx of the middle finger being folded in repose forwards on the upper surface of the metacarpal bone; by the tail, which either perforates the interfemoral membrane or is produced far beyond it; and by the upper incisors, which are generally a single pair separated from the canine and also in the middle line. The family is cosmopolitan like the Vespertilionidæ, but rarely extends north or south of the thirtieth parallel of latitude.

Subfamily Emballonurinæ.-Tail slender, perforating the interfemoral membrane, and appearing upon its upper surface, or terminating in it; legs long, fibula very slender; upper incisors weak.

In the Furipterine division the tail terminates in the interfemoral membrane; the crown of the head is greatly elevated above the face-line; the thumb and first phalanx of the middle finger are very short; and the dentition is i, c, p, m; total 38.

1

Represented by two genera, Furipterus 1 and Amorphochilus,2 each including one species of peculiar aspect; the latter distinguished from the former by the widely separated nostrils and the great extension backwards of the bony palate. Habitat South America.

In the typical or Emballonurine division part of the tail is included in the basal half of the interfemoral membrane, the remain1 Bonaparte, Faun. Ital. vol. i. (1832-41): Syn. Furia, F. Cuvier, Mém. du Muséum, vol. xvi. p. 150 (1828). Preoccupied by Linn. 1766.

2 Peters, Monatsber. Ak. Berlin, 1877, p. 185.

ing part passing through and appearing upon its upper surface; the crown of the head is slightly elevated; the pollex and first phalanx of the middle finger are moderately

long; and the number of the premolars is always 3.

Emballonura.1-Incisors. Extremity of the muzzle more or less produced beyond the lower lip, forehead flat. Contains some five species, inhabiting islands from Madagascar through the Malay Archipelago to the Navigators' Islands.

FIG. 312.-Ear of Emballonura raffrayana. x2. (Dobson, Proc. Zool. Soc. 1878.)

Coleüra.2-Incisors 3. Extremity of the muzzle broad, forehead concave. Has two species from East Africa and the Seychelles Islands.

Rhynchonycteris. This genus is distinguished from Coleüra by the much-produced extremity of the muzzle. The single species, R. naso, from Central and South America, is very common in the vicinity of streams throughout the tropical parts of these countries; it is usually found during the day resting on the vertical faces of rocks, or on the trunks of trees growing over the water, and, owing to the peculiar grayish colour of the fur covering the body and growing in small tufts from the antebrachial membrane, so as to counterfeit the weathered surfaces of rocks and the bark of trees, easily escapes notice. As the shades of evening approach it appears early on the wing, flying close to the surface of the water, and seizing the minute insects that hover over it.

Saccopteryx.-Incisors. Antebrachial membrane with a pouch opening on its upper surface. This genus contains six species from Central and South America. In the adult males a valvular longitudinal opening is found on the upper surface of the membrane, varying in position in different species. This opening leads into a small pouch (in some species large enough to hold a pea), the interior of which is lined with a glandular membrane secreting an unctuous substance of a reddish colour with a strong ammoniacal odour. The presence of this sac only in males indicates that it is a secondary sexual character analogous to the shoulder-pouches of Epomophorus and the frontal sacs of Hipposiderus. It is quite rudimentary in the females.

Taphozous.5-Incisors; upper pair deciduous. This genus, represented by some ten species, inhabiting the tropical and subtropical parts of all the eastern hemisphere except Polynesia, forms the second group of this division, distinguished by the cartilaginous

1 Temminck (Van der Hoven), Tijdsch. Nat. Ges. 1839, p. 22.

2 Peters, Monatsber. Ak. Berlin, 1867, p. 479. 3 Peters, loc. cit. p. 477.

4 Illiger, Prodromus Syst. Mamm. et Avium, p. 121 (1811).

5 Geoffroy, Descript. de l'Egypte, vol. ii. p. 126 (1812).