HEAD OF THE LYRE BAT.
The extraordinary development of the ears and of the membranous appendages of the nose is greatest in the species of this genus, which has in consequence been denominated Megaderma, two of which inhabit tropical Asia, whilst two occur only in the warmer parts of Africa.
Of all the species the most abundant and best known is the Lyre Bat (Megaderma lyra, see [figure]), which is found with but little variation in its characters throughout continental India, from Cashmere to Cape Comorin, and also in the adjacent island of Ceylon. This extraordinary little creature, which measures only about three and a half inches in length, and is of a slaty blue colour, paler beneath, has its ears considerably longer than its head, and united for nearly half the length of their inner margins, and the earlets (tragi) very long, divided at the end into two parts, one of which, the posterior, is pointed, and a good deal longer than the other, which is rounded off at the end. The ears are, in fact, about half the length of the head and body. The nose-leaf starts from a nearly circular base, lying horizontally upon the muzzle, and rises like a sort of strap more than half an inch long, the front surface of which has a projecting ridge running up its middle, and corresponding to a deep groove on the posterior surface. The nostrils are situated in the concavity of the basal disc from which the nose-leaf springs. In this and the other species of Megaderma there are no incisor teeth in the upper jaw (see [figure]), the intermaxillary bone itself, which ought to bear these teeth, being represented only by a cartilaginous piece, which fills up the space between the canines; and the tail is exceedingly short, and contained in the basal part of the interfemoral membrane, which is large, and has its hinder margin concave, and not pointed as in most Bats.
TEETH OF THE LYRE BAT.
The great size of the ears and nasal appendages in these Bats has led Europeans in India to give them the name of Vampires, as they agree in these particulars with the true Vampire Bats of South America, and the name is certainly better applied to them than to the frugivorous Pteropidæ, which are sometimes called Vampires even by zoologists. It is, however, a singular fact that in both these groups the extraordinary developments of membrane about the head should be proved to co-exist with more bloodthirsty habits than are common to the Bats generally. It does not indeed appear to be absolutely made out that Megaderma lyra condescends to partake of that insect diet which contents so many of its fellows. As Mr. Dobson remarks, “The very peculiarly-shaped, elongated, narrow muzzle and large trenchant canines, with acutely-pointed basal cusps (see [figure]) of this and of the other species of Megaderma, the projecting mandible and divided lower lip, so different from all Insectivorous Bats, naturally lead us to suspect corresponding differences in habits.” And he goes on to say that in examining the stomach and intestines of numerous specimens of the present species, he always found them either perfectly empty or filled with a pultaceous matter, in which no remains of insects were to be recognised. Mr. Hodgson, however, found insects in the specimens examined by him. But whether it contemns insects or not, an observation made by the late Mr. Blyth suffices to prove that higher forms of animal life, and indeed its own near relations, are exposed to its attacks. The account given by Mr. Blyth is so interesting that, although rather long, we may give it entire:—
“Chancing one evening,” he says, “to observe a rather large Bat enter an outhouse, from which there was no other egress than by its doorway, I was fortunate in being able to procure a light, and thus to proceed to the capture of the animal. Upon finding itself pursued, it took three or four turns round the apartment, when down dropped what at the moment I supposed to be its young, and which I deposited in my handkerchief. After a somewhat tedious chase, I then secured the object of my pursuit, which proved to be a fine female of Megaderma lyra. I then looked to the other Bat which I had picked up, and, to my considerable surprise, found it to be a small Vespertilio, nearly allied to the Pipistrelle of Europe, which is exceedingly abundant, not only here, but apparently throughout India. The individual now referred to was feeble from loss of blood, which it was evident the Megaderma had been sucking from a large and still bleeding wound under and behind the ear; and the very obviously suctorial form of the mouth of the Vampire was of itself sufficient to hint the strong probability of such being the case. During the very short time that elapsed before I entered the outhouse, it did not appear that the depredator had once alighted; and I am satisfied that it sucked the vital fluid from its victim as it flew, having probably seized it on the wing, and that it was seeking a quiet nook where it might devour the body at its leisure. I kept both animals separate till next morning, when, procuring a convenient cage, I first put in the Megaderma; and after observing it for some time, I placed the other Bat with it. No sooner was the latter perceived than the other fastened upon it with the ferocity of a Tiger, again seizing it behind the ear, and made several efforts to fly off with it; but finding it must needs stay within the precincts of its cage, it soon hung by the hind legs to the wires of its prison, and after sucking its victim till no more blood was left, commenced devouring it, and soon left nothing but the head and some portions of the limbs.”
HEAD OF THE CORDATE LEAF BAT.
