MIMOMYS 473 



Pitymys are combined with a peculiar skull (resembling, how- 

 ever, that of some species of Microtus, rather than any of 

 Pitymys) and the essential external characters of Microtus. 



Pitymys is of rather southern distribution, ranging in the 

 Old World from Belgium, France, eastwards to Rumania, and 

 south to the coast of the Mediterranean, including Greece, 

 Sicily, and Trebizond, Asia Minor, while one species at least 

 inhabits central Asia (Turkestan). In the New World it is 

 found in the eastern and south-eastern United States, with 

 Mexico. 



It is numerous in species, no less than twenty-five distinct 

 forms being recognised by Miller as European. Of these, 

 P. subterraneus, De Selys, is present in Belgium and northern 

 France, just across the English Channel. In Britain it makes 

 its earliest known appearance, the remains of three or 

 four species having been found in the Cromerian Upper Fresh- 

 water Bed, a late Pliocene deposit. It may then have died out, 

 for, with the exception of a single n^ doubtfully ascribed to it 

 by Hinton from the early Pleistocene (" High Terrace") of the 

 Thames Valley, no trace of the genus is known from the 

 succeeding epochs. 



Hinton regards the original home of Pitymys as in central 

 or southern Asia, whence he believes that it spread westwards 

 via Asia Minor to western Europe, and eastwards to North 

 America by north-eastern Asia. The discovery of slightly 

 more primitive species (/*. majori and P. carruthersi) in Asia, 

 and of the aberrant M. irene and its allies, lends support 

 to this view. 



[Genus MIMOMYS.^ 



This genus was instituted by Forsyth Major {Proc. Zool. 

 Soc, London, 1902, i., 103-107) for his M. plioccsnicus of the 

 upper Pliocene of Italy, and the Norwich Crag of Britain ; for 

 his M. newtoni and for Arvicola intermedius of Newton 

 [Mem. Geol. Survey, 1882, 83), both the last from the late 



' Extinct. Wrongly assigned to Phenacomys by Nehring {Naturw. Wochenschrift, 

 No. 231, 15th July 1894, 346), and subsequently included by him in his Dolomys 

 {Zool. Anzeiger, loth Jan. 1898, 15), from which latter it was distinguished by Forsyth 

 Major {supra). 



VOL. II. 2 H 



