HEAD OF MALE AND FEMALE
BLACK-BEARDED BAT.
(After Dobson.)
SKULL OF RHINOPOME.
(After Dobson.)
This Bat, described by the French traveller and naturalist Belon, about the middle of the sixteenth century, under the name of the Egyptian Bat (Chauve-Souris d’Egypte), is one of the most singular members of the order Chiroptera. It presents so curious a combination of characters that its place in the system has always been uncertain; and owing to the presence of a small nose-leaf, it has hitherto been arranged by different writers with the Phyllostomata, the Rhinolophidæ, and the Nycteridæ. Its true place, according to Mr. Dobson’s recent researches, appears to be with the Emballonuridæ, with which, and especially with the Taphozoi, it certainly agrees closely in the form of the skull and the dentition. This view of the relationships of the genus Rhinopoma seems also to have struck Cuvier, who, while placing the genus next to Nycteris, makes Taphozous immediately follow it.
EGYPTIAN RHINOPOME.
The genus is characterised by having the crown of the head considerably elevated, with a deep concavity in the forehead between the eyes, as in Taphozous; the muzzle considerably elongated beyond the opening of the mouth; the nostrils of valvular structure, situated in the anterior margin of a very small, erect nose-leaf, which bears some resemblance to those of the Phyllostomes; the ears rather large, united upon the forehead (a Nycterid character), and furnished with a well-developed tragus; and the tail long and slender, and free throughout almost its whole length from the interfemoral membrane, which is exceedingly short. The upper incisors are two in number, and of very small size, inserted in intermaxillary bones which unite with the maxillaries by slender processes, a character which also occurs in Emballonura. In the lower jaw there are four incisors in a close row. The canines are strong, and followed on each side by a single pre-molar in the upper, and two in the lower jaw; and there are three true molars with W-shaped cusps on each side in both jaws: thus the dental formula is—incisors, 1–14, canines, 1–11–1, pre-molars, 1–12–2, molars, 3–33–3. The index finger consists of three joints, a metacarpal bone and two phalanges, a structure which occurs in no other Insectivorous Bats.
The Egyptian Rhinopome, which is probably distributed over a considerable portion of the African continent, is a small Bat, the length of the head and body being only about two inches and a quarter. The portion of the tail free from the membrane is about the same length as the head and body, and the interfemoral membrane encloses about another half-inch. It has a nearly naked face, along the middle of which a narrow groove runs back from the base of the little nose-leaf to the deep concavity situated in the forehead between the eyes; the wing-membranes are attached to the tibia for about two-thirds of the length of the latter, and are entirely free from hair; and the small development of the membranes, coupled with the comparatively great length of the limb-bones, renders this Bat more active in walking than most of his fellows. The fur is short, and leaves a good deal of the hinder part of the back naked; and the bare skin thus exposed, as well as the base of the wings, is curiously wrinkled, a character which this species has in common with certain species of Taphozoi and Molossi.
The Egyptian Rhinopome is found commonly in Egypt, where it frequents the numerous ruins and old buildings with which that country abounds, and is particularly abundant in the dark galleries and chambers of the Pyramids.[223]