478 MURID^— ARVICOLA 



Pisa, resembles A. terrestris, but has less heavy teeth, lighter 

 colour, and cheeks not in contrast with the surrounding parts. 

 A. illyricus (Barrett-Hamilton) of Bosnia differs from the last 

 in having whitish under parts. A. musignani of de Sdys, at 

 present known only from the west coast of central Italy (Rome), 

 is a pallid edition of italicus. 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 S6lys), of the Pyrenees 

 is strictly terrestrial and mole-like, and is of special interest 

 because of its relationship to A. abbotti of the late Pleistocene 

 of Britain (see under Distribution in time on last page). 



The habits resemble those of Microtus, except as modified 

 by a special tendency to either an aquatic or a fossorial 

 existence. 



Origin: — Arvicola is evidently of Asiatic origin. The 

 distribution of the North American Aulacomys suggests a real 

 relationship, but the time has not yet come for a final decision. 



THE BRITISH WATER RAT. 



ARVICOLA AMPHIBIUS (Linnaius). 



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-laooks, 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, Hist. 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 raton 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) :—^/a<:^, or water dog, Aberdeenshire 

 (Macgillivray) ; earth-hound {cf. Norwegian [ordrotte = '' ^zxt\). rat") 

 heard once by Sim ; water mole of Cambridge (Jenyns) ; water ratten 

 of upper Nidderdale • water ra/— universally. 



