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that the species does not hibernate (nor I fancy does any Indian Bat, even in the lofty and cold sub-Himalayas, under at least 5000 feet of elevation); that it is entirely nocturnal, though capable of a vigorous flight even at noon of a sunny day; that it is exclusively insectivorous, and has no such cannibal propensities as are stated to belong to one of its congeners, nor consequently are its haunts entirely avoided by the smaller species of true Bat (Vespertilio proper) though the numerousness of its own race leaves not much room for the intrusion of strangers; that the males and females dwell together promiscuously even when the females are gravid and nearly parturient, and therefore probably always; that the young are seemingly driven away so soon as they can shift for themselves, all those taken by me having been well grown; that the females bring forth in spring and perhaps also in autumn, the latter point resting on information, the former on the fact that all my females were, on the 26th February found variously, but far, advanced in their pregnancy; that the males are more numerous than the females in a high proportion, or from to more; that the females bring forth only a single young one at a time, not one instance of double gestation occurring among my numerous specimens; and, lastly, that no other species dwells mixedly with this Megaderme, though a species of true Bat of diminutive size was found tenanting the same house, and the two were observed to issue forth at night from their respective and distinct domiciles simultaneously, and so as constantly to cross each other in their flight, a flight sustained by both with equal power, yet without any aggression of the larger on the smaller kind.
Having said so much of the manners of our animal I proceed to its form and structure, merely premising that I think it is a true Megaderme, although its phalangial system is apparently irreconcileable with Cuvier's general or Geoffroy's particular definitions in that respect,* for it has two bony phalanges to the thumb, two also to the index, and three to each of the remaining fingers. In other respects it is a complete Megaderme and a striking examplar of a Genus of Bats, which, though diffused throughout the plains of India, is absolutely unknown in the mountains, at least on the sub-Himalayas. The Megadermes * See Regne animal, Vol. II, pp. 7 and 10, Vol. V. p. 74, Nat. Libr. Vol. XII. I, p. 123, and Vol. VII. p. 74. So far as my observation of the Family of Bats goes the phalangial system of our specimen is unique, and, should it prove so, the type might be denominated Eucheira.
appear to be found all over the plains of India and its islands, extending thence to Africa; and wherever found they are as numerous in individuals as scant in species, only three distinct kinds being yet recorded, notwithstanding the immense geographic diffusion of the Genus. The subject of the present paper is however, I believe, a novelty, and to the careful description of it I now proceed.
The Slaty Megaderme of the Tarai is 34 inches long from snout to vent, the head, to the occiput, 11, the ear to the lobe, 11⁄2, the caudal membrane (for there is no tail) 14, the arm 1, the forearm 21, the longest finger 5, the thigh 18, the leg 1, the planta and nails,, the expanse 18, and the weight 2 oz. Sex makes no difference in size or aspect, and immaturity, after the growth is well advanced, little or none. The colour of the fur is, for the most part, a clear deep slaty blue above and sordid buff below, of the membranes deep brown, and of the eye, very dark. Females resemble males. Juniors have the slaty hue less pure or smared with brown. The moderate-sized and depressed head ends bluffly to the front, where the simple and adpressed lips are covered with downy piles and short divergent hairs, except in front of the lower lip which is nude and faintly grooved. Two moderately large and roundish plates are laid flat on the nose, one above and the other below the ovoid nares, which lie hid completely between them. The upper plate becomes at the base of the bridge of the nose somewhat narrowed, and then is continued into an erect free process, more or less concave, and divided longitudinally by a central ridge; the shape of the process being elliptic. The eyes, which have a backward and laterally remote position, are small, but still larger considerably than in the Bats proper or in the Rhinolphes, though less so than in the Pteropines. The immense nude and rounded ears have their bases low down and forward, so as nearly to pass under the eye, where there is a vague antitragal development, and immediately above it, but quite distinct, rises the inner ear consisting of an acute spire, and a small rounded process, in line with it, which latter is sometimes notched on its round edge. The true ears are united over the forehead above half way to their tips and of course can therefore have very little mobility. Nor do the ears exhibit any of that exquisite sensibility for which the ears of the Rhinolphes are so remarkable. The body is muscular and strong with a large sternal keel or crest, and is covered abundantly with
silky hair of one kind that is laxly applied to the skin, and more or less wavy in some specimens, smooth in others. The flying apparatus, or alar and caudal membranes, are very ample, the latter being extended to the heel or tarse, and so as, when expanded, to run straight across from heel to heel. The alar membrane commences at the centre of the forearm's length, takes in the first joint of the thumb, makes a large angle so as to envelope the long mid-finger, and then passes pretty evenly to the heel. There is no trace of tail, nor any caudal vertebræ. The thumb has two equal bony joints, whereof the first is enveloped in membrane and the second free and nailed as usual. The index has one entire joint and a second rudimental, which however is half an inch long nearly, and all the other digits have three complete bony phalanges each. There are two pectoral and two enguinal teats, whereof the latter are the larger and bear more appearance of having been sucked. The penis is pendant: the tests internal: the womb simple; there is no frontal sinus: stomach purely membranous and globose, with proximate orifaces intestines from 11 to 14 inches, of pretty equal calibre, and having a grain-like cœcum, inch long, at 1 to 14 inches from the anal end of the gut: great arch of stomach 3 to 3; lesser to 2: Lungs 2-lobed: Liver 2-lobed, each subdivided, and a lobulus: Gallbladder grain-like (size and shape of a grain of finest rice) and freely suspended in the cleft of the largest lobe of the liver. Contents of stomachs, insect remains solely of uteri, single young, much advanced in growth, with all the organs formed and the mouth open, but quite nude. The scull, the walls of which are as thin as paper, is much curved culmenally and very ample in dimensions in all the regions of the brain: the crests, longitudinal and transverse, small but traceable: the frontals flat, short and laterally bounded by sharp ridges: the nasals,* wanting: orbits large and very incomplete: auditory cavities double : lower jaw straight with very low condyles. Teeth 2:44. No trace of incisors in the upper jaw, nor of any bone or cartilage to sup* The deficient bones are apparently not merely the intermaxillars but the nasals, of which there is no trace, and the cavity in front of the scull is consequently very large. However in all the 7 specimens now before me the cranial sutures are well nigh or wholly obliterated. Quere? Are not the nasal bones wanting in all the typically istiophorous Bats? for, if not, how could the complex and delicate external apparatus of the nose have the requisite freedom of communication with the nervous and circulating systems, there being no special orifaces observable in the malars or frontals. In fact, the ant-orbitar formamina are very small in these Bats, and I have noticed no others.
port them; lower incisors pressed between the canines and denticulate on their crowns: laniaries large, curved, angular, with spiculate processes before and behind at their base: molars purely insectivorous, their crowns bristling with spikes and filling the entire space from the laniaries to the posteal edge of both jaws. Tongue moderately extensile and simple.
The following are the dimensions in detail of a fine mature speci
I have just obtained, for the first time, a sample of the genus Plecotus, and one very nearly allied to the common English type so admirably described by McGillivray in the VII. Vol. of the Nat. Lib. p. 85-90. My specimen was taken in the central region of the mountains, in a dwelling house, where it was attracted at night by the lights, and after a chase of above half an hour's duration, during which the extraordinary volant powers of this Bat several times caused its