Bats are most widely diffused over the surface of the globe, as their powers of flight might lead us to expect. Even Australia—so very peculiar in the character of the other beasts which inhabit it—possesses bats belonging to both of the bat families which are found in our own island.
But, although the whole group of bats, and also that family to which most English bats belong—the Vespertilionidœ—are thus widely distributed, the geographical limits of some families of bats are very sharply defined.
To appreciate these facts it is necessary to be acquainted with the geographical areas into which the surface of our globe may be divided, each considerable tract of the earth's surface having its more or less peculiar animal population, or fauna, as it has its indigenous plants, that is, its flora. The earth's surface is divisible into six zoölogical regions:
1. The Palœarctic region, or Europe, Asia north of the Himalayas, and Africa north of the Sahara.
2. The Ethiopian region, or Africa south of the Sahara, and including Madagascar and also Arabia, which, geologically, is part of Africa.
3. The Oriental region, or Asia south of the Himalayas, with Southern China and the Philippine Islands and Indian Archipelago as far as the island of Bali.
4. The Australian region, or Australia, New Zealand, the less remote Pacific Islands, and those of the Indian Archipelago from New Guinea up to Lombok.
5. The Neotropical region, or South America, together with tropical North America and the West Indies.
6. The Nearctic region, or temperate North America and Greenland.
Now, the whole group of flying-foxes is strictly confined to the tropical regions of the Old World and Australia. In the same way the family of leaf-nosed bats, like those of England—the Rhinolophidœ,—is limited to the Old World, though reaching there much higher latitudes than do the flying-foxes.
The group to which the vampires belong—the Phyllostomidœ—is strictly confined to the Neotropical and Nearctic regions; and the
