Although the bats, from their great powers of flight, are not amenable to the limitations which determine the distribution of other terrestrial mammals, yet certain great facts of distribution come out in a very striking manner. The speciality of the Neotropical region is well shown, not only by its exclusive possession of one large family (Phyllostomidæ), but almost equally so by the total absence of two others (Pteropidæ and Rhinolophidæ). The Nearctic region is also unusually well marked, by the total absence of a family (Rhinolophidæ) which is tolerably well represented in the Palæarctic. The Pteropidæ well characterize the tropical regions of the Old World and Australia; while the Vespertilionidæ are more characteristic of the Palæarctic and Nearctic regions, which together possess about 60 species of this family.

The bats are a very difficult study, and it is quite uncertain how many distinct species are really known. Schinz, in his Synopsis Mammalium (1844) describes 330, while the list given by Mr. Andrew Murray in his Geographical Distribution of Mammalia (1866), contains 400 species. A small number of new species have been since described, but others have been sunk as synonyms, so that we can perhaps hardly obtain a nearer approximation to the truth than the last number. In Europe there are 35 species, and only 17 in North America.

Fossil Chiroptera.—The fossil remains of bats that have yet been discovered, being chiefly allied to forms still existing in the same countries, throw no light on the origin or affinities of this remarkable and isolated order of Mammalia; but as species very similar to those now living were in existence so far back as Miocene or even Eocene times, we may be sure the group is one of immense antiquity, and that there has been ample time for the amount of variation and extinction required to bring about the limitation of types, and the peculiarities of distribution we now find to exist.

Order III.—INSECTIVORA.

Family 14.—GALEOPITHECIDÆ. (1 Genus, 2 Species.)

General Distribution.
Neotropical
Sub-regions.		Nearctic
Sub-regions.		Palæarctic
Sub-regions.		Ethiopian
Sub-regions.		Oriental
Sub-regions.		Australian
Sub-regions.
— — — —— — — —— — — —— — — —— — — 4— — — —

The singular and isolated genus Galeopithecus, or flying lemur, has been usually placed among the Lemuroidea, but it is now considered to come best at the head of the Insectivora. Its food however, seems to be purely vegetable, and the very small, blind, and naked young, closely attached to the wrinkled skin of the mother's breast, perhaps indicates some affinity with the Marsupials. This animal seems, in fact, to be a lateral offshoot of some low form, which has survived during the process of development of the Insectivora, the Lemuroidea, and the Marsupials, from an ancestral type. Only two species are known, one found in Malacca, Sumatra, and Borneo, but not in Java; the other in the Philippine islands (Plate VIII. vol. i. p. 337).

Family 15.—MACROSCELIDIDÆ. (3 Genera, 10 Species.)

General Distribution.
Neotropical
Sub-regions.		Nearctic
Sub-regions.		Palæarctic
Sub-regions.		Ethiopian
Sub-regions.		Oriental
Sub-regions.		Australian
Sub-regions.
— — — —— — — —— 2 — —1 — 3 —— — — —— — — —

The Macroscelides, or elephant shrews, are extraordinary little animals, with trunk-like snout and kangaroo-like hind-legs. They are almost confined to South Africa, whence they extend up the east coast as far as the Zambezi and Mozambique. A single outlying species of Macroscelides inhabits Barbary and Algeria; while the two genera Petrodromus, and Rhyncocyon, each represented by a single species, have only been found at Mozambique.