EVOTOMYS 399 



longer than a hind foot, and thus intermediate between those 

 of lemmings and true mice. In their more ordinary hands and 

 feet the palms and soles are provided with pads. Voles are 

 thus externally less specialised, but cannot be absolutely 

 separated from the lemmings, since a few members of either 

 group exhibit the characters of the other. The fur is usually 

 soft, the colours rarely bright. The skull is comparatively 

 slender and lightly built. In the teeth the lower incisors are 

 long, and the extremities of their roots lie on the outer sides of 

 their mg ; the cheek-teeth have the dentine-spaces subequal, 

 and their upper crowns become distinctly narrower from front 

 to back. 



These are hardy animals, never hibernating, and continuing 

 their activity in winter beneath the snow of boreal countries. 



The group is of wide and almost ubiquitous distribution in 

 the extra- tropical regions of the Northern Hemisphere, where 

 a number of genera have been for the most part recently 

 differentiated. There are several British species, which fall into 

 three existing genera {Evotomys, Microtus, Arvicola) ; a single 

 extinct genus (M-imomys) ; and a genus and sub - genus 

 {Pitymys and Ckionomys), extinct in Britain, but still existing 

 in continental Europe. 



Genus EVOTOMYS. 



i8n. Myodes, p. S. Pallas, Zoographia Rosso-Asiatica, i., 173, based on Mus 

 lemmus of Linnaeus, hence antedated by Lemmus, Link, 1795 ; de S^lys- 

 Longchamps, Etudes de Micromammalogie, 1839, 87, section based on Lemmus 

 rubidus of Baillon, 1834 = Mus glareolus of Schreber ; Lataste, Le Naturaliste, 

 iSth October 1883, 349, sub-genus based on Mus rutilus of V^'s.i,— Evotomys 

 rutilus. 



1831. Hypud^us, misprinted Hypudacus (col. 874) and Hypudeus, (pi. vii.), 

 E. Mehlis, Oken's Isis, viii., based on H. hercynicus of Mehlis = yl/aj glareolus of 

 Schreber ; Keyserling and Blasius, Die Wirbelthiere Europa's, 1840, viii., and 34, 

 sub-genus based on Mus glareolus of Schreber ; preoccupied by HYPUDiEUS of 

 Illiger, Prodromus Sysi. Mamm. et Avium, 181 1, 87; the latter based on Mus 

 lemmus of Linnasus, hence antedated by LEMMUS, Link, 1795. 



1874. Evotomys, Elliott Coues, Proc. Acad. Nat. Sci. (Philadelphia), 186 ; genus 

 based on Mus rutilus of Pallas. 



1900. EuoTOMYS, Erwin Schultz, Zeitschr.fiir Naturwiss. (Stuttgart), 19th December, 

 203 ; CoUett. 



