THE BATS. 37 



for a short distance above the forehead, and the presence of grooves, re- 

 presenting an incipient nose-leaf on the muzzle just behind the nostrils. 

 When at rest, the long ears are folded 

 back, leaving the tragus alone standing 

 upright. In the allied genus (Synotus), of 

 which the barbastelle is the British repre- 

 sentative, .there are also only two species, 

 one of which is European and the other 

 Asiatic. They may be easily distinguished 

 from the long-eared bats by the shortness of 

 the ears, which are united for some distance 

 basally, and likewise by the reduction in the 

 number of the teeth from 36 to 34. 



The pipistrelle, or common bat (Vesperugo pipistrellus), together with the 

 much larger noctule (F. noctula) and serotine (V. serotinciis), are British repre- 

 sentatives of a third genus, differing in several particulars from the two pre- 

 ceding. There are, for instance, no traces of grooves or foldings in the skin of 

 the nose, and the small ears are completely separate from each other. The 

 genus, which apparently contains a greater number of species than any other 

 in the order, has an almost cosmopolitan distribution, but is one somewhat 

 difficult to define, as some of its representatives approximate more or less to 

 other genera ; the number of teeth being either 30, 34, or 36. The more 

 typical kinds may be recognised by the relatively stout body, the broad, flat- 

 tened head and blunt muzzle, and the broad, short, and triangular ears, in 

 which the tragus is generally thickened and somewhat inclined outwards. 

 As a rule, the hind-legs are short, and the membrane connecting them with 

 the tail nearly always has an additional portion on the outer side of the spur on 

 the heel. Omitting notice of the genera Nycticejus and Chalinolobus, mention 

 must be made of the American genus Atalapha, of which the hoary bat (A. 

 cinerea) of the United States is a familiar representative. All members of 

 this genus have but a single pair of upper incisor teeth, and are further char- 

 acterised by the membrane between the hind-legs being more or less hairy. 

 Like other bats living in cold climates, the hoary bat hibernates during winter ; 

 this species selecting caves, to which it resorts in large numbers for the period 

 of torpor. Many European bats prefer, however, church-towers and roofs, or 

 outbuildings, while some select hollow trees, and it is a curious fact that in 

 the case of certain species the males and females associate in separate colonies. 

 An unusually warm day, even in mid-winter, will generally cause a certain 

 number of bats to awake from slumber and issue forth, after which they again 

 fall into the same torpor as before. 



Among the numerous genera of this family, the tube-nosed bats (Harpyio- 

 cephalus), from hilly districts in the Oriental countries, Tibet and Japan, 

 deserve special mention, on account of the remarkable similarity be- 

 tween the structure of their nostrils and those of the tube-nosed fruit- 

 bats. In the present genus the tubes into which the nostrils are pro- 

 longed are, however, shorter and much more divergent than in the last- 

 named group. 



Of the typical genus (Vespertilio}, which is only second in point of numbers, 

 there are four British representatives, among which Daubenton's bat (V. dan- 

 bentoni) is one of the best known. Those bats differ from the members of the 

 family already noticed in having upwards of 38 teeth, there being two pairs 

 of incisors in the upper jaw ; and they are specially distinguished by the circum- 



