THE MAMMALS OF SURREY. 183 
Brown Rat (M. decwmanus). —A club has been formed at 
Witley for the destruction of this pest, a penny per tail of an 
adult Rat being paid. I have seen one or two melanic ex- 
amples. One in the Haslemere Museum is wrongly labelled 
‘Black Rat.” 
Common Fieup Voie (Microtus agrestis). — Common every- 
where. 
rosa 

YELLOW-NECKED MovusE AND Woop Mouss, To sHow RELATIVE SIZES 
(reading from left to right). 
Bank Voie (M. glareolus).—At one time this Vole was con- 
sidered something of a rarity, but it is in reality one of the 
commonest of mammals—at least as far as Surrey is concerned. 
There seems to exist a good deal of confusion in the discrimina- 
tion of this Vole and the above species, which has probably led 
to its being overlooked. A simple key to the two is as fol- 
lows :—Tail very short; under parts grey = M. agrestis. Tail 
