EUROPEAN REDBACKED MICE 9I 



teeth and in the second and thh-d upper mohirs. The triangles in the 

 upper molars are closed throughout; those of the lower molars are 

 occasionally and apparently quite irregularly open. In arrangement 

 the triangles are essentially as in Evotomys norvegiciis. In the first 

 lower molar, however, the anterior loop is longer, and deeply cut by 

 a well developed reentrant angle on the inner side (scarcely indicated 

 in E. tiorvegicus) which isolates a third closed triangle fully equal- 

 ling the others of the same side in size. In the posterior upper molar 

 the two external reentrant angles are approximately equal in depth, 

 while in E. iiorvcgiciis the more anterior of the two is exceedingly 

 shallow and often obsolete. 



Measiu'cments. — A well made skin from Qiiickjock, Sweden, 

 measures: total length 150; tail vertebrae 40; hind foot with claws 

 19. 8; hind foot without claws 18. 



Specimens examined. — Five, from the following localities : Nor- 

 way ; Stabursnaes, Porsanger, i, Tanen, Finmarken, 2. Sweden; 

 Qinckjock, i, Tornea, i. 



Rctnarks. — Evotomys riifocanus is so readily distinguishable by its 

 subgeneric characters that it needs no special comparison with other 

 members of the genus. 



Subgenus EVOTOMYS Coues. 



EVOTOMYS RUTILUS (Pallas). 

 1778. Mus ruiihis Pallas, Nov. Spec. Ouadr. e Glir Ord, p. 246. 

 1874. Evotomys rutilus QoMYS, Proc. Acad. Nat. Sci., Philadelphia, p. 187. 

 1899. A\jiaptogojiia\ rutila Cope, Journ. Acad. Nat. Sci., Philadelphia, 2d 

 ser., XI, p. 201. 



Type locality. — Siberia, east of the Obi. 



Faunal position. — Evotomys rutilus is strictly confined to the up- 

 per boreal zone. 



Geographic distribution. — Arctic Europe and Asia, south in Nor- 

 way to Tromso.^ 



General characters. — Size small (total length about 125, hind foot 

 1 8, greatest length of skull 24) ; tail forming about 20 percent of 

 total length, very densely haired, its pencil at least ^ as long as verte- 

 brae ; dorsal stripe clear bright chestnut, sharply but not conspicuously 

 contrasted with color of sides. 



Color. — An adult male from northern Sweden taken in December 

 has the dorsal stripe clear bright chestnut, faintly darkened by a 

 slight admixture of black-tipped hairs. Sides ochraceous buff. 



iCollett, Nyt Mag. for Naturvidenskaberne, XXXVI, p. 282. INIarch, 1898. 



