384 MURID^— MICROTIN^ 



from Britain, the Ultima Thule of their wanderings, must be 

 regarded as due solely to local causes, perhaps connected with 

 the latest Glacial Period, or to the competition in large numbers 

 of the more highly organised Muridce. Having been exter- 

 minated in Western Europe, they were unable to return to 

 Britain in time to reoccupy it. The absence of the Hamster, 

 Cricetus cricetus (\J\nn-&w^)^ fromSkandinavia, Denmark, Britain, 

 the Iberian Peninsula and Italy, marks the present stock as being 

 recent immigrants to the rest of Europe ; the immigration is 

 perhaps still in progress, the species having much extended 

 its range in France since 1870 (see A travers le monde, v., 41, 

 14th October 1899, 325-326).] 



Sub-family Microtince.^ 



VOLES AND LEMMINGS.^ 



The classification of this sub-family is largely due to Miller, 

 and is a natural system in contradiction to the artificial 

 arrangements of most previous investigators — de Sdlys, 

 Blasius, Patio, Baird, Coues, Blanford, and Lataste ; for 

 references to the works of whom, and for further technical 

 details, see Miller's " Genera of Voles and Lemmings," being 

 North Amer. Fauna, No. 12, 1898 ; also Hinton's " Preliminary 

 Account of the British Fossil Voles and Lemmings," in Proc. 

 Geol. Assoc, 3rd June 1910, 489-507. 



Characters :— These rodents are all burrowers, more or less 

 completely adapted to an earthbound or even a subterranean 

 existence, and therefore lacking the variety of shape and habits 

 which is so prominent a feature of the CricetincB and Murina. 

 Their eyes are usually small, and their external ears reduced in 

 size. 



In the skeleton the pubic symphysis is greatly shortened. 

 In accordance with the diet of coarse and tough vegetable 



1 The report of its naturalisation in South Ronaldshay, Orkneys, "having been 

 brought there in a Norway vessel, which suffered shipwreck," was shown by John 

 Wolley {Zoologist, 1849, 2344) to be an error, perhaps based on the known presence 

 of Epimys rattus. 



^ Arvicolina of many older writers. 



2 "Lemming," from the Swedish and Norwegian, probably =" destroying." 



