t or very small; tail scaly, more or
less naked, cosmopolitan (_Alston_). Three molars in each jaw, the
first of which is the largest and the hinder one the least. I think
that, with the exception of the islands of the Pacific Ocean, some
of the members of this family are known in every quarter of the globe.

_GENUS MUS_.

"Muzzle pointed; eyes prominent; ears rather large, sub-naked; fur
soft (rarely mixed with spines); pollex rudimentary; claws short;
tail moderate or long, scaly, with scattered hairs; no cheek pouches;
skull elongate, narrow; temporal ridges nearly parallel; palate
compressed; incisive foramina long; auditory bullae moderately
large; coronoid process high, falcate; incisors rarely grooved;
molars with transverse ridges, each composed in youth of three
tubercles" (_Alston_).

NO. 332. MUS RATTUS.
_The Black Rat_ (_Jerdon's No. 175_).

NATIVE NAMES.--_Kala-mus_, _Kala-chuha_, Hindi; _Kala-meeyo_,
Singhalese.

HABITAT.--Chiefly Europe, but is said to be of south Asian origin;
it is stated to occur in towns near the sea-coast in India, and
Kellaart obtained it in Trincomalee only.

DESCRIPTION.--Greyish-black above, dark ashy beneath, or, as
Kellaart describes it, "above blackish-brown, along the dorsal line
nearly black; sides paler, some of the hairs with pale fulvous tips;
beneath and inside of limbs fur very short, of a uniform sooty ash
colour, separated from the colour above by a distinct line of
demarcation; ears large, rounded, slightly fulvous externally"
('Prodromus Faunae Zeylanicae,' p. 58).

[Illustration: Dentition of Black Rat.]

SIZE.--Head and body about 6-1/2 to 7-1/2 inches; tail, 7-1/2 to 8
inches.

Jerdon says of this rat that the muzzle is sharper than that of the
brown rat; the ears are more oval; it is lighter in its make, and
has much longer hair.

Whether this rat be, as Jerdon seems to suspect, imported into India
in ships or not, it is generally supposed to have had its origin in
southern Asia, and is almost identical with the Egyptian rat (_M.
Alexandrinus_). It was the common rat of England, and indeed of
northern Europe, whence it was expelled by its formidable rival, the
brown rat, before which it has gradually receded, and it is seldom
found now in England.

NO. 333. MUS DECUMANUS.
_The Brown Rat_ (_Jerdon's No. 176_).

NATIVE NAMES.--_Ghur-ka-chuha_, Hindi; _Demsa-indur_, Bengali;
_Manei-ilei_, Canarese; _Gaval-meeyo_, Singhalese.

HABITAT.--Th