THE MOUSE TRIBE. : 139 
THE Mo.e-LIkE VOLES. 
Genera Ellobius and Siphneus. 
Certain representatives of the vole group are specially adapted for a sub- 
terranean mole-like life, and, therefore, differ considerably from the other forms, 
although they retain the ordinary type of molar teeth. In form they are 
characterised by the blunt and rounded head passing imperceptibly into the 
cylindrical mole-like body, the absence of external ears, the short tail and limbs, 
and the broad feet, each provided with five claws. The incisor teeth project 
considerably, and their enamel is usually white, instead of having the yellow 
or orange tinge so prevalent among the ordinary voles. 
These mole-like voles, of which there are but few species, are mainly confined 
to Central and Northern Asia, although one species ranges as far south as 
Afghanistan and Quetta, and another extends into Eastern Europe. They are 
divided into two genera, according as to whether the claws of the fore-feet 
are short or long; Allobius including the short-clawed and Siphneus the long- 
clawed species. ‘The so-called Quetta vole (Z. fuscicapillus) is about 5 inches in 
total length, of which half an inch is occupied by the tail. It is brownish white 
above, with the exception of the greyish brown head, while the under-parts, feet, 
and tail are white; the fur being long and soft. It is reported to construct 
horizontal galleries in the ground, with heaps of earth thrown up at intervals, 
after the fashion of the mole. 
THE RATS AND MICE. 
Genus Mus. 
The true rats and mice, together with certain allied forms referred to distinct 
genera, are the representatives of the last subfamily of the Muride, which is 
exclusively confined to the Old World. They are primarily characterised by the 
crowns of the unworn upper molar teeth carrying a number of tubercles arranged 
in three longitudinal rows; these teeth always having distinct roots. When worn 
by use, the crowns of the molars exhibit transverse bands of enamel. The tail is 
always long and scaly, and in most cases almost destitute of hairs. Moreover, 
the ears are large, and the eyes bright and prominent, while the muzzle is sharply 
pointed, and the build light and elegant. Their movements are quick, active, and 
graceful, and their coloration is in most cases uniform and sombre, as would 
naturally be expected from the nocturnal and burrowing habits of the majority 
of the species. 
The Murine subfamily includes a considerable number of species, by far the 
greater majority of which are comprised in the genus Mus. That genus is character- 
ised by the incisor teeth being smooth, and the molars distinctly tuberculated. 
The ears and eyes are proportionately large, and the tip of the muzzle is naked, 
while the tail is long and scaly. The first toe of the fore-foot has a short nail in 
lieu of a claw; and the fur is soft, although in some cases intermingled with 
