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long, and contained within the interfemoral membrane ; and the intermaxillary bones are present, and 
bear four incisor teeth. In the lower jaw there are six incisors. The canines, as in Megaderma, are 
large and powerful ; there is a single pre-molar on each side in the upper, and two in the lower jaw, and 
the true molars are three on each side in both jaws. 
These characters are common to all the species of the genus Nycteris, most of which are 
inhabitants of the continent of Africa. The Desert Bat (A. thebaica) is found in the desert regions 
of Egypt and Abyssinia, and receives its name from its occurrence in the Thebaid, that desert 
the caves of which gave shelter to so many hermits in early Christian times. It is a small Bat, the 
length of its head and body being about two and a half inches. Its ears are longer than the head. 
the desert bat. (Uue-luitJ Natural Size.) 
and the tail is about as long as the body, and enclosed within an ample interfemoral membrane, which 
is stretched on each side by a long heel-spur. The fur is of a grey colour.* 
These Bats possess an exceedingly curious faculty, namely, the power of inflating the skin with 
air. The skin adheres to the body only at certain points, where it is connected by a loose areolar 
tissue, and the spaces thus left can be filled with air at the pleasure of the animal, through the large 
cheek-pouches, which have an opening at the bottom, and thus communicate with the spaces under the 
loose skin. When the animal chooses to inflate its skin it fills its lungs with air, and then, closing the 
mouth and nostrils, and contracting the chest, forces the air through the openings in the check-pouches 
under the skin. Its return is prevented by sphincter muscles, with which the above-mentioned 
apertures are provided, and also by large valves on the neck and hack. By this means the Bat has the 
power of inflating its skin to such an extent as to resemble, according to Geoflroy, “a balloon with 
wings, a head, and feet attached to it.” Geoflroy compares this condition of tilings with that of the 
fish of the genus Tetraodon , which also have the power of inflating their skins with air, but adds that 
* Other described African species are N. capcmis (Smith) ; N. macrot/x (Dobson) : N. h hpida (Schreber) ; and N. gmndis 
(Peters). The only species found out of Africa is the Javanese Desert Bat (N. javanica). 
