The Taphozoi have a rather short and broad head, with a tapering muzzle, its breadth behind the eyes being due to the wideness of the zygomatic arches. The ears are separate, and their outer margins sweep round upon the cheek, terminating near the angle of the mouth; the tragus is short, somewhat widened at the apex, so as generally to have a hatchet shape; the wings are long and narrow, and the interfemoral membrane is ample, and stretched by very long spurs, between the tips of which its hinder margin is concave; the base of the tail is enclosed in the membrane, from which its tip projects. The teeth, especially the canines and upper true molars, are powerful, and the latter show the W-shaped cusps very distinctly. There are three molars and two pre-molars in each jaw, but in the upper jaw the hindmost molar is reduced to a narrow transverse plate, as shown in the [figure], and the first pre-molar is so small as scarcely to project above the gum. In the lower jaw there are four small incisors; but in the upper jaw the pre-maxillary bones are represented only by cartilage, which in the young, and sometimes in adult animals, bears a pair of minute teeth, separated from each other by a wide space, but these apparently frequently drop out as the animal advances in age. In consequence of this structure, the skull presents a peculiar appearance. The intermaxillary cartilage being lost, the front of the face presents a deep notch between two projecting processes which bear the canine teeth, and even during life the lower jaw extends further forward than the upper one, so that its incisor teeth press only against the upper lip.
DENTITION OF TOMB BAT,
ENLARGED.
Another curious character presented by most of these Bats is the existence under the chin of a peculiar pouch (see figure, [p. 316]), which sometimes occurs in both sexes, although smaller in the females, and is sometimes altogether wanting in the latter. In some, the place of this sac, which is evidently of a glandular nature, seems to be represented by a group of small pores. The purpose of this peculiar arrangement is not clearly known; but from the greater development of the organ in the males of those species which possess it, it would appear to be of a sexual character. The peculiar wing-pouches which characterise the genus Saccopteryx are wanting in these Bats; but in most of them there is a small membranous band, enclosing the angle formed by the tip of the fore-arm and the base of the fifth finger, and thus forming a little pouch.
The Tomb Bat (Taphozous perforatus) is one of those which presents a pouch of this description, and the male also possesses a large throat-sac, which is altogether wanting in the females. It is about three inches in length, exclusive of the tail, which is thin at the extremity; the wing-membranes extend down to within about a quarter of an inch of the ankles, and the heel-spurs are about as long as the tibia. The body is covered with short dark-brown fur, which extends over the bases of the wings, and down the interfemoral membrane as far as the point where the tail emerges from it.
This is the species originally discovered by Geoffroy in the chambers of the Pyramids, and other tombs and buildings in Egypt. It is said also to inhabit Sennaar and Senegal. It flies in the evening, passes the day in the darkest places it can find, and feeds exclusively upon insects. These habits, indeed, appear to be common to all the species of the genus.[221]
THE EGYPTIAN RHINOPOME.[222]
HEAD OF MALE AND FEMALE
LONG-ARMED BAT.
(After Dobson.)
