RODENTIA—MURINAE—-MUS RATTUS. 
439 
The brown rat is well known over the world for its destructive propensities and the injury it 
causes to house and store. According to Pallas, it belonged originally to the warmer regions of 
Central Asia, Persia especially. Thence it crossed the Volga, in large troops, in 1737, peopled 
Russia, and subsequently overspread the whole of Europe. According to Erxleben, it reached 
England in 1730, and France in 1750. In 1775 it was taken to North America, some time 
subsequent to the black rat, which it soon drove out and nearly exterminated. At the present 
time no portion of the globe seems free from its pernicious presence, although, as it is usually 
transported in ships, its first foothold is on and near the seacoast. In 1851, Audubon and Bach¬ 
man spoke of it as not found on our Pacific coast. At the present time, however, it is very 
abundant there as far north as the Columbia river. 
List of specimens. 
MUS RATTUS, L. 
Black Rat. 
1Ifus ratlus, Linn/Eds, Syst. Nat. I, 1766. 
DeKay, N. Y. Zool. I, 1842, 79. 
Aud. and Bach. N. Am. Quad. I, 1849, 189 ; pi. xxiii. 
Giebel, S’augt. 1855, 655. 
Mus americanus, DeKay, N. Y. Zool. I, 1842, 81; pi. xxi, f. 1. 
Mus nigricams, Raf. Am. Month. Mag. Ill, 1818, 446. 
Sr. Ch. —Tail about as long, or a little longer, than the head and body. Above, sooty black, passing insensibly into 
dark plumbeous on the belly ; sometimes a little paler. Feet brown ; fur of the back without the longer coarse bristles of 
the brown rat. 
This species may be readily distinguished from the common brown rat by the much darker 
colors. In a specimen from Montreal, the upper parts are of a lustrous sooty black, with a green 
