Ears shorter than the head, oval-triangular, deeply notched on their external margins; tragus nearly straight, terminating in a blunt rounded head: fur reddish brown above; somewhat paler beneath.
V. Pipistrellus, Desm. Mammal, p. 139. Jen. in Linn. Trans, vol. xvi. p. 163. Le Pipistrelle, Buff. Hist. Nat. torn. vin. pi. 19. f. 1. Common Bat, Penn. Brit. Zool. vol. i. p. 148.
Length of the head and body one inch seven lines; of the head six lines; of the tail one inch two lines; of the ears four lines; of the tragus two lines ; breadth of the ears three lines; of the tragus threequarters of a line; length of the fore-arm one inch two lines; of the thumb one line and three quarters: extent of wing eight inches four lines.
Resembling the Noctule in many of its characters but much smaller : head depressed in front, convex behind; muzzle short in the adult state, somewhat elongated when young; nose obtuse at the extremity, and slightly emarginated between the nostrils; a protuberant swelling on each side of the face above the upper lip formed by a congeries of sebaceous glands: eyes very small; above each an elevated wart furnished with a few black hairs: ears broad, oval-triangular, rather more than half as long as the head, with their external margins deeply notched about midway down: tragus half the length of the auricle, nearly straight, oblong, with a blunt rounded head: tail as long as the fore-arm. Fur rather long and silky, yellowish red on the forehead and at the base of the ears, on the rest of the upper parts reddish brown, with the lower half of each hair dusky; on the under parts wholly dusky, except the extreme tips of the hairs which are of the same colour as above, but paler. Young specimens generally brownish gray, sometimes black, without any tinge of red. Nose, lips, ears, and membranes dusky.
The most common species in this country, although for a long time confounded with the V. murinus described above. Congregates in large numbers in the crevices of old walls, decayed door-frames, etc. Resists cold more than the other species, continuing on wing till near the end of the year. Is first seen about the beginning of March.