AMERICAN WHITE-FOOTED MOUSE. 301 



hairs ; no scales being visible like those on the common mouse, (Mus 

 mtisculus.) 



Fur, from the roots to near the extremity, dark bluish-gray ; on the 

 upper parts, brownish yellow ; being a little darker on the crown and 

 back, and lighter on the sides ; the colour of the cheeks and hips ap- 

 proaches reddish-brown. The above is the colour of this species 

 through the winter and until it sheds its hair late in spring, when it as- 

 sumes a bluish-gray tint, a little lighter than that of the common 

 mouse. Whiskers, white and black ; upper surface of the tail, the 

 colour of the back. The lips, chin, throat, feet, legs, and the whole 

 under surface of the body and tail, are pure white. On the sides, this 

 colour extends high up along the flanks ; there is a very distinct line of 

 demarcation between the colours of the back and sides. 



There are some varieties in this species ; specimens which we ex- 

 amined, from Labrador, Hudson's Bay, and Oregon, were lighter in 

 colour, and the white on the under surface extended farther toward the 

 back, than on those from the Atlantic States ; we also observed a strik- 

 ing diff"erence in the length of their tails, some being longer than the 

 body, whilst others were not much more than half the length. In size 

 they also differ \videly ; we have seen some that are scarcely larger than 

 the common mouse, whilst others are nearly double that size ; they are 

 considerably larger in Carolina than in the Eastern States. 



DIMENSIONS. 



Length of head and body 

 " tail 



Another specimen. 



Length of head and body 



" tail . 



2i 



inches. 



2i 



do. 



31 



do. 



31 



do. 



HABITS. 



Next to the common mouse, this is the most abundant and widely dif- 

 fused species of mouse in North America. We have received it (under 

 various names) from every State in the Union, and from Labrador, Hud- 

 son's Bay, and the Columbia River. Being nocturnal in its habits it is 

 far more common than is generally supposed. In familiar localities, 

 where we had never known of its existence, we found it almost the 

 only species taken in traps at night. 



