Encyclopaedia Britannica, 11th Edition, "Chicago, University of" to "Chiton" / Volume 6, Slice 2

by Various

Fig. 8.—Head of Persian Leaf-Bat. (Triaenops persicus). From Dobson.

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.

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 False 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 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.

Fig. 9.—The False Vampire (Megaderma gigas). From Dobson.

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 Vampires. 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.

Fig. 10.—Head of Blainville’s Vampire (Mormops blainvillei). From Dobson.

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.