are covered with yellowish-red enamel. The molars are rooted, and in the young
are crowned with tubercles, which in the upper jaw are arranged in three longitudinal
rows, and in the lower jaw in two rows; when the teeth become worn
they are crossed with folded transverse laminae.
Dental Formula.—I. f ; C. P.M. $ ; M. |.
Most of the members of the genus frequent underground galleries and holes
which they excavate in the earth, and are more or less nocturnal in their habits.
The Harvest Mouse is an exception, for it makes its nest in shrubs and growing
vegetation, whilst the Wood Mouse sometimes places its nest below ground and
sometimes on the surface.
