EUROPEAN REDBACKED MICE 97 



about one lialf length. Audital bulla) shorter and broader than in E. 

 norvegicus. 



Measurements of an adult skull (the type) : Greatest length 25. S; 

 basal length 23.6; basilar length 21.8; zygomatic breadth 14; mas- 

 toid breadth 12: interorbital constriction 4.2; nasals 7.4; incisive 

 foramen 5; diastema 7; palatal length 11.4; occipital depth (in 

 median line) 7 ; f ronto-palatal depth (at middle of molar series) 

 ().(>\ mandible 15.4; maxillary toothrow (alveoli) 6; mandibular 

 toothrow (alveoli) 5.6. 



Teeth. — The teeth are more heavily built than in E. noi-veglctis., 

 the difference most noticeable in the second and third molars. 



Meas7iremetits. — Average of tw^o specimens from the type locality : 

 total length 160; tail vertebrae 52; hind foot w^ith clavv^s20.2; hind 

 foot without claw^s 18.5. For details see table, page 106. 



Specimens examhzed. — Tw^o, both from the type locality. 



Remarks. — The discovery of Evotomys vasconice completes an illus- 

 tration of the distribution of a boreal group of mammals in western 

 Europe. Three isolated but closely related species of large European 

 redbacked mice are now known, one each in the boreal zone of Nor- 

 way, the Alps, and the Pyrenees.^ The small E. hercynicus occupies 

 the lower zones throughout the region Intermediate between the ranges 

 of E. fwrvegicus and the two other large species. That these are 

 similarly Isolated from each other Is scarcely to be doubted. Evo- 

 to7nys hercynicus has been traced southward to the lower Garonne, 

 less than 150 miles from the type locality of E. vasconice, while 

 there Is no apparent barrier to Its occurrence throughout the lowlands 

 from the Department of Gironde to the Gulf of Lyons, thus effectually 

 separating E. vasconice from E. nageri. 



EVOTOMYS HERCYNICUS (Mehlis). 

 (Synonymy under subspecies.) 

 Type locality. — Harz Mountains, Germany. 



Faunal position. — Evotomys hercynicus Is probably a character- 

 istic species of the transition and upper austral zones. 



Geographic distribution. — Non-mountainous portions of Europe, 

 from southern France and the valleys of northern Switzerland, north to 



' Montrejeau, the type locality of E. vasconicz:, is probably in the Transition 

 zone. Evotomys, however, can readily descend to this level at the base of a 

 mountain chain by taking advantage of local conditions (see Miller, Science, 

 NS., VIII, pp. 615-618. November 4, 1S9S.) Mr. Young's specimens were 

 taken in heavy woods. 



