296 MURIDJE. 



the Mus sylvaticus are in being of a darker colour, smaller, 

 and with some of the relative proportions rather less."* 

 As we have ourselves observed considerable variation in 

 size and colour, we can only regard these Irish examples 

 as varieties of Mus sylvaticus. 



The Field Mouse is larger than the Common Field Vole, 

 but varies considerably in size ; the head is long and raised ; 

 the muzzle tapering ; the whiskers very long ; the eyes 

 remarkably large and prominent ; the ears large, oblong, 

 oval, with the anterior margin turned in at the base, and 

 a projecting lobe arising within the ear near the base of 

 the posterior margin ; the tail nearly as long as the body, 

 slender and tapering ; the legs long. The upper part 

 and sides of the head, neck, and body, and the outer 

 surface of the legs of a yellowish colour, mingled with 

 blackish, or of a yellowish brown, darker on the back ; 

 each hair being grey or ash colour at the base, then 

 yellow, and the tips of some of them black ; under parts 

 whitish, with a very slight greyish tint in some parts, and 

 a yellowish-grey patch on the breast. Tail brown above, 

 white beneath. 



Dimensions : 



* Notes on some of the Smaller British Mammalia, &c., by the Rev. 

 Leonard Jenyns, M.A., F.Z.S., &c. Annals of Natural History, Vol. VII. 

 No. 44. June, 1841. 



