EUROPEAN REDBACKED MICE 87 



THE GENUS EVOTOMYS AND ITS SUBGENERA. 



Genus EVOTOMYS Coues. 



1874. Et'o/omys CouES, Proc. Acad. Nat. Sci. Philadelphia, ■ p. 186. Type, 



J/us rutiliis Pallas. 

 1899. Anaptogofiia Cope, Journ. Acad. Nat. Sci. Philadelphia, 2d ser., yi, 

 p. 201 (part). 

 Generic characters. — Teeth rooted as in Phenacoinys ; palate ter- 

 minating in a thin-edged shelf between alveoli of posterior molars. 



Remarks. — The genus Evotomys as thus defined includes two well 

 characterized subgenera, one represented by the aberrant Evototnys 

 riifocajuis alone, th6 other containing the typical species. It is a 

 boreal genus of circumpolar distribution, extending south to the transi- 

 tion zone in America, and apparently somewhat farther in Europe. 



Subgenus EVOTOMYS Coues. 



Type. — Evotomys rtitilus Pallas. 



Characters. — Skull smooth and rounded, the postorbital processes 

 obsolete ; teeth relatively much smaller than in JMicrotiis, the molar 

 row considerably shorter than diastema; roots of molars fully formed 

 relatively early in life ; root of posterior lower molar not forming an 

 obvious swelling where it comes in contact with root of incisor. 



Remarks. — The subgenus Evotomys is a very compact and well 

 characterized group. It contains all the known species of the genus, 

 EvotoDiys I'ufocamis excepted, and its range is coincident with that of 

 the genus. 



Subgenus CRASEOMYS subgen. nov. 



Type. — Evotomys rufocamis (Sundevall). 



Characters. — Skull as strongly angular as in Microtus., the postor- 

 bital processes well developed ; teeth relatively as large as in Microtus., 

 the molar row about equal to diastema ; roots of molars developed late 

 in life ; root of posterior lower molar lying in a distinct capsule on 

 lingual side of incisor root. 



Remarks. — The subgenus Craseomys shows a distinct approach to 

 Microtus in the general character of the skull, and in the encapsuled 

 posterior lower molar. The palate, on the other hand, and the molar 

 roots, are typical of Evoto?nys. 



THE EUROPEAN SPECIES OF EVOTOMYS. 



Ten forms, species and subspecies, of redbacked mice are now 

 known to inhabit Europe. Their characters are as follows : 



