The large and mobile ears give this Bat an appearance of size not justified by its small and delicate build. The head and body combined measure less than two inches, whilst the tail is only a fraction less than that measurement. The fact that no other European Bat has such an equipment renders a detailed description superfluous, for the ears at once distinguish this from all the other species. These ears have their bases joined across the forehead. Their form is a long oval with rounded tip. Except for fringes on the folds they are hairless. They are semi-transparent and have transverse folds. The tapering tragus is nearly half as long as the ear, and might be mistaken for it when the Bat hangs asleep; for then the ears are carefully folded and tucked away in the wing whilst the tragus sticks out beyond the inanimate-looking bundle. Sometimes, when awake, one ear is held at a different angle from the other; but in flight both ears are directed forward. Often, when it has caught an insect, the Long-eared Bat will come to the ground to eat it. The soft, silky, brown fur is long and thick, especially on the shoulders, but does not extend far upon the wings. On the under parts it pales to yellowish or dirty white. The wings are both long and broad, and their expanse in flight is about ten inches. The long tail when folded forwards can touch the top of the head; its tip is slightly free from the interfemoral membrane, and when the Bat hooks itself up head downwards for sleep it serves as a third foot. The Long-eared Bat is found chiefly among trees, though it frequently comes into open windows at night when its hunting is over. It flies among the branches of trees and examines the foliage for insects of all kinds. In early spring, when the sallows are in bloom and attracting swarms of insects, the Long-eared Bat is there also: fresh from hibernation and with a keen appetite. He hovers like a hawk over a favourable tree, and swoops down upon his selected prey. He appears in the evening usually about half an hour after the sun has departed, and apparently feeds during the greater part of the night; occasionally he is active in daylight. He appears to be at least partially migratory, for it has been observed that in summer a swarm will appear in a district where they are not noticeable as a rule, and after staying a few weeks disappear. The single young one is born in June or July. They are often found hibernating in clusters under house-roofs; but solitary individuals are also found in hollow trees and similar situations. Should the thermometer register 46° F. or more at any time during the winter, the Long-eared Bat awakes and makes a foraging flight--calling attention to his presence by his acute, shrill cry. The dental formula is: _i 2/3, c 1/1, p 2/3, m 3/3 = 36_. *Barbastelle* (_Barbastella barbastellus_, Schreber).