Page:EB1911 - Volume 06.djvu/259

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 another—an arrangement which has the great advantage of bringing together all the Vampires.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 defining 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.

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.

Fig. 11.—Head of Lesser Javelin Vampire (Phyllostoma elongatura).

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