MURID^ 



381 



(b) Upper incisors not notched ; ;«i about 

 equal in length to /«^ and m^ to- 

 gether : — 



(a') Size smaller; "mice" with condylo-1 



basal length rarely exz^^^vcx^APODEMUS. 

 28 mm. . . . .] 



(a) Skull comparatively massivel a ^ ■ „■ 



and angular . . y.^avuo/hs. 



(b) Skull comparatively light and smooth : — 



(a') Size smaller (condylo-basaH . , ,. 

 length not exceeding 24 mm. )|^- ^-^^^«^^^^^- 



(b') Size larger (condylo-basal length 

 not less than 24 mm.) : — 



(a) Skull slender; coronoid] , 

 process of mandible re-^ 

 duced . . .J 



(fS) Skull normal ; coronoid pro- 

 cess of mandible not re- 

 duced : — 



fridariensis 

 Island). 



(Fair 



(a) Size smaller 



basal length 24-25 mm, 



(condylo-\ 

 * J 



A. 



hebridensis 

 Hebrides). 



(Outer 



(/3') Size larger (condylo-basan },:„,,„,:, (^,v--,\a.s 

 length 25-5-27 mm.) .J^' ^«'^«'«" (=5' Kilda). 



(b') Size larger; 



basal length rarely less 

 38 mm. . 



rats " with condylo-1 

 inV 



than \EP1MYS. 



(a) Size smaller (condylo - basal' 



length rarely reaching 45 mm.) ; 

 cranium broader(externallength 

 of a parietal distinctly less than 

 breadth of cranium between 

 lateral ridges) ; ni}- without 

 anterior cingulum, with dis- 

 tinct outer tubercle to first 

 lamina 



(b) Size larger (condylo-basal length" 



rarely less than 45 mm.) ; cra- 

 nium narrower (external length 

 of a parietal about equal to 

 breadth of cranium between 

 lateral ridges) ; mS with an- 

 terior cingulum, without outer 

 tubercle to first lamina 



E. rattus.* 



E. norvegicus. 



The sub-species of Epimys rattus are omitted, as they do not possess diagnostic cranial or 

 dental characters. 



VOL. II. 



2 B 2 



