268 
BATS. 
band at their bases, which in some species is so slightly developed as to be almost 
invisible. Moreover, these bats have well-developed tails, and also upper incisor 
teeth, the total number being 32, of which § on each side are incisors, \ canines, 
and § cheek-teeth. So different, indeed, are the bats of the genus Nycteris from the 
false vampires, that the reader might well wonder why the two are associated in a 
single family. There are, however, important resemblances in the form and structure 
of the head and skull, among which—as characters visible externally—may be men¬ 
tioned the pointed and cylindrical muzzle, and the projection of the lower jaw beyond 
the upper; these being sufficient to establish the near relationship of the two groups. 
With the exception of one species (N. javanica ) from Java and the Malay 
Peninsula, the bats of this genus are confined to Africa, where they are mostly 
restricted to the regions south of the Sahara, although one of them ranges into 
Egypt. 
The Typical Bats. 
Family VESPERTILIONID^E. 
With the exception of the horseshoe-bats already described, the whole of the 
bats found in the British Islands, and, indeed, in Europe generally, may be included 
in a single family, which may conveniently be designated popularly as the typical 
bats, and is scientifically known as the Vespertilionidce. All these bats agree with 
the two preceding families in the relation of the tail to the membrane between the 
legs; but they are distinguished by the absence of a distinct nose-leaf, the nostrils 
merely forming circular or crescent-shaped apertures at the end of the muzzle 
without any complications from foldings of the skin. Their tails are long, and 
produced to the edge of the membrane between the legs; and their ears are always 
furnished with a distinct tragus. Apart from certain details in the structure of 
their skulls which need not be mentioned here, it may be observed that the incisor 
teeth of the upper jaw are always of small size, those of opposite sides being 
separated from one another by a considerable interval, while their number varies 
from one to two pairs. The lower incisor teeth, on the other hand, are, with 
one exception, three pairs. Moreover, there are generally either six or five cheek¬ 
teeth on each side of both upper and lower jaws, the reduction in number in the 
latter instance being due to the disappearance of one of the premolars. 
In addition to being the common bats of Europe, the typical bats have an almost 
world-wide distribution, and include more than one hundred and fifty distinct species. 
The absence of the nose-leaf, together with other features in their organisation, 
indicates that they are less specialised types than the two preceding families, to 
which, however, they are in other respects intimately related. Accordingly, 
Dr. Dobson considers that in the typical bats we have the descendants of the 
ancestral forms which gave rise both to the Nyctericlce and the horseshoe and 
leaf-nosed bats; and we may thus regard all these three families as forming a 
single distinct branch of the insectivorous bats ; the main stem of this branch being 
formed by the Vespertilionidce, and the other two families forming side branches. 
The number of these bats being so great, all that can be done here will be to 
select a few of the better-known examples of some of the more important genera. 
