THE GREAT HARE-LIPPED BAT.[224]
In Seba’s well-known illustrated book on Natural History a peculiar species of Bat is described and figured under the name of “Vespertilio cato similis americanus.” It may be doubtful whether any of our domestic Grimalkins would be much flattered by the likeness thus briefly indicated (see [figure]), but there can be no doubt that the animal in question was a Bat, and as such it duly appears in the earlier editions of the “Systema Naturæ” of Linnæus. By a curious misapplication of the very sound principle of not being guided exclusively by external characters, the great Swedish naturalist was led in the last edition of his work (in which he founded the genus Noctilio) to refer the animal to the Rodents, on the ground of the apparent presence of only two incisors in each jaw.
A glance at the dentition of a Noctilio will at once show how Linnæus was misled, and at the same time that it has all the dental characters of a Bat. In the upper jaw there are four incisor teeth, the two middle ones approximated and considerably larger than the lateral ones, which are placed quite behind them, leaving a small open space between the incisors and the larger canines, behind which comes a series of four molars showing the characteristic W-shaped cusps very distinctly. In the lower jaw there are only two small notched incisors, followed immediately by the powerful canines, behind which is a series of five molars, the first very small, the second larger, but simple and pyramidal, and the remainder with distinct cusps and ridges.
HEAD OF GREAT
HARE-LIPPED BAT.
The ears in the Bats of this genus are rather large and furnished with a small tragus, the outer margin of which is notched. The outer margin of the ear forms a rounded lobe upon the cheek, and is then continued to the angle of the mouth. The upper lip is widely cleft, forming a broad margined fissure running up to the nostrils, which are surrounded by borders raised to such an extent as to give them almost a tubular appearance; and the lower lip, which is also thickened, bears several curious folds of skin; the whole in combination giving a most singular and forbidding expression to the little creature. The wing-membranes descend but little below the knee, but the interfemoral membrane is ample, stretched by very long spurs, and traversed in its basal part by the short tail, the tip of which projects from its upper surface like a little knob.
The great Hare-lipped Bat (Noctilio leporinus), which is distributed over the whole of tropical and sub-tropical South America, from the West Indies in the north to Paraguay and Chili in the south, is about three inches and three-quarters in length without the tail, and has an expanse of wing of about twenty-one inches. The general colour of the fur on the back is greyish-brown or reddish-brown, but in many specimens a yellowish-white streak runs from the nape down the middle of the back to the root of the tail. The throat, neck, and belly are reddish-yellow, the ears, membranes, and other naked parts blackish-brown. The interfemoral membrane extends about two inches beyond the tail, which is three-quarters of an inch long, and the heel-spurs are more than an inch in length.
This Bat lives in large parties in hollow trees, caverns, the roofs of buildings, and even among the dense foliage of trees, but generally in the immediate vicinity of water. In the twilight they are seen in great numbers flying, almost in the same way as the Swallows in Europe, in great flocks over the surface of the water, close to which they skim with a very rapid flight in pursuit of the insects which constitute their food. The voice is described by Prince Maximilian of Neuwied as a hissing sound. According to an observation made by Mr. Louis Fraser in Ecuador, the object of the Noctilio in haunting the waters is not so peaceful as that of most bats, which, so far as we know, resort to the lakes and rivers only to drink. Mr. Fraser describes it as flying along the banks of rivers, and from time to time dashing down upon the surface of the water, where it captures small Crustaceans as they swim up the stream. He adds that the Bats have a fishy odour, and possibly they do not strictly confine themselves to invertebrate prey.[225]
CESTONI’S BAT.[226]
We come now to a series of Bats (the Molossi of Professor Peters and Mr. Dobson) which we shall treat here as belonging to three genera, the classification and nomenclature of which are attended with considerable difficulty, partly owing to the variability of characters on which we are accustomed to rely in the definition of generic groups, and partly to the confusion which has arisen in the use of the generic names employed especially by the older writers. They are all stoutly and rather clumsily built Bats, with short, thick muzzles, a character which has obtained for some of them the name of Bulldog Bats; the tail is thick, and projects beyond the margin of the interfemoral membrane, the hinder limbs are short and stout, and the fibula or second bone in the shank is well developed, often nearly as large as the tibia.