Imágenes de páginas

Distribution Of Rodents (continued). Deductions

[merged small][graphic][table]
[merged small][graphic][table]

1. The Order Rodentia is the most numerous of all the chief Mammalian groups, containing nearly 1400 species, which are divided into 170 genera and 21 families.

2. The Rodents are distributed all over the world both in temperate and tropical climes, and are abundant everywhere, both in species and individuals, except in Australia where they are poorly represented.

3. The most all-pervading and numerous family of the Rodents is the Muridm (Mice), which are upwards of 600 in number and are the only members of the group met with in Australia and Madagascar. In Madagascar the Mwridm are represented by a small group of indigenous genera.

4. The Porcupine-like Rodents, of which there are seven families, are specially characteristic of the New World, only the typical Porcupines (Hystricidm) and five peculiar genera of Octodonts being inhabitants of the New World.

5. Two families of Rodents, the Pocket-gophers (Geomyidm) and the Kangaroo-rats (Heteroinyidm), are specially characteristic of the Nearctic Region, the Jerboas (Dipodidm) of the Patearctic, and the Sand-rats (Bathyergidie) of the Ethiopian Region.



Section I.—Distribution Of Hybaxes

The Hyraxes and Elephants are nowadays often annexed to the Ungulates, and arranged only as Sub-orders of that great Order, to some members of which they have been shown to be more or less allied by forms of life now extinct. But as, in the present case, we are dealing only with existing mammals, it seems better to give to these two groups their full rank as "Orders," which they have an abundance of special characters to justify. The Hyraxes, of which, taking Mr. Thomas's recently published account1 as our guide, about fourteen species belonging to the single genus Hyrax are more or less accurately known, may be regarded as a characteristic form of the Ethiopian Region. As shown by Mr. Thomas's map (op. cit. p. 58) they are distributed all round the coast of Africa from Senegal through the Cape to Upper Egypt, and also in many places, where they have been searched for, in the interior. Beyond the African continent they extend through Arabia into the borders of Palestine, where the celebrated " coney " of the Scriptures (Hyrax syriacus)

1 "On the species of the Hyracoidea," by 0. Thomas, P. Z. S. 1892,

« AnteriorContinuar »