RODENTIA. 143 
thing that comes within their reach. There are three species which 
have become quite common in our houses, viz. 
M. musculus, L.; Buff. VI, xxxix. (The Common Mouse. ) 
Universally known. 
M. rattus, L.; Buff. VII, xxxvi. (The Black Rat.) Of which 
no mention is made by the ancients, and which appears to have 
entered Europe in the middle century. It is more than double 
the size of the Mouse in each of its dimensions. The fur is 
blackish. Several individuals have been occasionally found 
connected by the interlacing of their tails; constituting what 
the Germans style the King of Rats.(1) 
M. decumanus, Pall.; Buff. VIII, xxvii. (The Norway or 
Brown Rat.) Which did not pass into Europe till the eigh- 
teenth century, and is now more common in large cities than 
the Black Rat itself. It is larger than the latter by one-fourth, 
and differs from it also by its reddish-brown hair.(2) 
These two large species appear to have originated in the 
East, and have been transported in ships, together with the 
Mouse, to all parts of the globe. 
Eastern Tartary and China have a Rat equal to the decu- 
manus. 
M. caraco, Pallas, Glir. XXIII; Schreb. clxxvii. (The Ca- 
raco Rat.) Of a light colour ; tail alittle shorter than the pre- 
ceding, and the jaws stronger. 
There is another in India, one-fourth larger than the Brown 
Rat, the Rat perchal, Buff. Supp. VII. Ixix, which is of a red- 
dish brown. There is a large one in the Indian Archipelago, 
the 
M. setifer, Horsf. Jay. Of a blackish brown. These last 
two species are bristled over with setaceous hairs, which ex- 
tend beyond the others. 
One of the largest and most mischievous Rats known is the 
M. pilorides, Pall. and Gm. (The Musk-Rat of the Antilles.) 
Fifteen inches in length without the tail, which is still longer 
than the body; hair coarse, of a deep black above, and whitish 
beneath.(3) 
(1) See Bellerman on the King of the Rats (in German), Berlin, 1820. 
(2) It appears to belong to Persia, where it lives in burrows. It was not till 
1727, that, after an earthquake, it arrived at Astracan, by swimming across the 
Volga. 
(3) Pallas and Gmelin erroneously describe it as being entirely white. The 
earlier historians of the colonies attribute to it the above colours, which are pre- 
cisely such as we have seen on the animal. 
