The use of this membrane, according to Dr. Dobson, is to serve as a tactile organ (like the wings); and this is the more probable, seeing that that family of leaf-nosed bats which is represented in England have the smallest eyes, and are devoid of a tragus or inner part of the seemingly double ear before spoken of.
Bats are divisible into two great groups. One of them includes all the insect-eating bats (with or without nose-leaves), more or less
Fig. 4.—British bats.
like the bats which inhabit this country. They have almost always teeth such as those already described, often a very large tragus to the ear, and a stomach short and rounded, or at least not prolonged at its pyloric (or more specially digestive) extremity.
These bats are subdivided into various families, three of which alone immediately concern us: 1. The Vespertilionidœ, which in-
