478 MURIDAZ—ARVICOLA 
Pisa, resembles A. terrestris, but has less heavy teeth, lighter 
colour, and cheeks not in contrast with the surrounding parts. 
A. wlyricus (Barrett-Hamilton) of Bosnia differs from the last 
in having whitish under parts. A. musignani of de Sélys, at 
present known only from the west coast of central Italy (Rome), 
is a pallid edition of ztalicus. A. scherman (Shaw) is a fossorial 
and partially terrestrial form with three sub-species, inhabiting 
continental Europe from Belgium and the Baltic to the 
Pyrenees, Alps, and Tirol; it has both palmar and plantar pads 
reduced in size, the skull distinctly fossorial, the inter-parietal 
bone being narrow and ligulate, and the incisors projecting ; one 
of its sub-species, A. s. monticola (de Sélys), of the Pyrenees 
is strictly terrestrial and mole-like, and is of special interest 
because of its relationship to A. addottz of the late Pleistocene 
of Britain (see under Distvzbution in time on last page). 
The habits resemble those of J/zcrotus, except as modified 
‘by a special tendency to either an aquatic or a fossorial 
existence. 
Origin:—Avvicola is evidently of Asiatic origin. The 
distribution of the North American Azdacomys suggests a real 
relationship, but the time has not yet come for a final decision. 
THE BRITISH WATER RAT. 
ARVICOLA AMPHIBIUS (Linneus). 
The British Water Rat occurs as two sub-specific forms described 
below. It is found all over England, Wales, and the mainland of 
Scotland, but is absent from Ireland and probably all other islands 
except Anglesey and Wight. 
Terminology :—It is the “Water Vole” of text-books, a name which 
originated, as in the case of other British species, with Fleming. All 
previous authors wrote of the “Water Rat,” apparently translating the 
“Rat d’eau” of French naturalists (e.g, Buffon, Wzs¢. Nat., vii. 368, t., 
xliii.). Jenyns’s “Water Campagnol” seems never to have become 
popular. The word “craber” from the French crabier, an abbreviation 
from vaton crabier (cf. Walton, Complete Angler, ed. 2, 73, 1655, “the 
craber which some call the water-rat”), seems to have fallen into disuse. 
Local names (non-Celtic):—d/ack, or water dog, Aberdeenshire 
(Macgillivray); earth-hound (cf. Norwegian /ordrotte =“ earth rat”) 
heard once by Sim; water mole of Cambridge (Jenyns); wader ratten 
of upper Nidderdale ; water vat—universally. 

