The transition from this to the next family is effected by two genera, which to such an extent combine the characters of the two as to have led different zoologists to place them sometimes in the one, sometimes in the other. Externally they have all the characters of the Mole-rats of the following family; in the characters of the skull and teeth they more resemble the Voles. The ZOKOR (_Siphneus aspalax_), which may be taken as an example of these forms, is an inhabitant of the Altai Mountains, has the eyes very small, the external ears reduced to mere rudiments, the body cylindrical, as in the true Mole-rats, and the fore-feet armed with very long and strong claws, of which that on the fifth toe is longer than the toe itself. This animal lives in subterranean runs something like those of the Mole, but of much greater extent, and in burrowing in the earth makes use of its strong incisors to cut through the roots it meets with, and when necessary to loosen the earth. The runs pass very near the surface, and are no doubt made for the purpose of feeding on the tender roots of grasses. A species of _Siphneus_ is said to occur in North China. The other genus (_Ellobius_) includes two species; one (_E. luteus_) from the country about the Sea of Aral; the other (_E. talpinus_) from south-eastern Russia and the west of Asia. The latter abounds in the Crimea. These animals form the sub-family Siphneinæ. CHAPTER III. MOLE RATS, POUCHED RATS, POUCHED MICE, JERBOAS, AND OCTODONTIDÆ. SPALACIDÆ, OR MOLE RATS--Characteristics of the Family--Habits--Food--THE MOLE RAT--Distribution--Description--THE CHESTNUT MOLE RAT--THE NAKED MOLE RAT--THE STRAND MOLE RAT--Description--Habits--THE CAPE MOLE RAT--GEOMYIDÆ, OR POUCHED RATS--Characteristics of the Family--The Cheek-pouches--THE COMMON POCKET GOPHER--Distribution--Description--Burrowing--Runs--Subterranean Dwelling--THE NORTHERN POCKET GOPHER--HETEROMYINÆ, OR POUCHED MICE--Difficulties as to Position--Characteristics--PHILLIPS’ POCKET MOUSE--Where Found--Description--THE YELLOW POCKET MOUSE--THE LEAST POCKET MOUSE--DIPODIDÆ, OR JERBOAS--Organisation for Jumping--Characteristics--Distribution--THE AMERICAN JUMPING MOUSE--Description--Characters peculiar to itself--Habits--THE TRUE JERBOAS--Characters--THE JERBOA--Distribution--Habits--Mode of Locomotion--THE ALACTAGA--THE CAPE JUMPING HARE--THE PORCUPINE-LIKE RODENTS--OCTODONTIDÆ--Characteristics--Sub-Family, CTENODACTYLINÆ--THE GUNDI--THE DEGU--Description--Habits--THE BROWN SCHIZODON--THE TUKOTUKO--THE CURURO--THE ROCK RAT--Sub-Family, ECHINOMYINÆ--THE COYPU--One of the Largest Rodents--Description--Burrows--Habits--Mother and Young--THE HUTIA CONGA--THE HUTIA CARABALI--THE GROUND RAT. FAMILY VIII.--SPALACIDÆ (MOLE RATS).