826 ROHENTIA 



black, and uuderparts entirely <lull wliitisli, i]\c pectoral spot 

 absent or barely indicated. 



External characters. — In general external characters Apodemus 

 fridariensis agrees with A. si/lvaticus and A. JlavicoUis, but the 

 ear is relatively not so large, barely covering eye when laid for- 

 ward, and the palmar and plantar tubercles are relatively smaller. 

 The latter peculiarity is especially noticeable in the hind foot, 

 where the area occupied by the pads as compared with the space 

 between them is distinctly less than in the related species. 



Colour. — ^Upper parts as in the darker less russet specimens 

 of A2yodemHS sylvaticus sijlvaticus, the black clouding of median 

 region and " lining " of sides more noticeable than usual in the 

 smaller animal, the " lining " effect on sides increased by a 

 certain harsh loose texture of the fur which causes the dark 

 hair-tips to stand out with unusual distinctness against the light 

 undercolour. Underparts a peculiar dull bluish white, noticeably 

 different from the clear white of A. fiavicoUix, and without trace 

 of the brownish wash so frequently indicated in A. sylvaticus, 

 though a faint buffy tinge is sometimes present ; pectoral spot 

 usually absent, bvit occasionally represented by a tuft of 

 brownish hairs. Tail very sharply bicolor, blackish above, 

 whitish below. Feet dull white. 



Skull and teeth. — In size the skull of Ajwdeyims fridariensis 

 rather exceeds that of the large Mediterranean forms of 

 A. sylvaticus, though by no means equalling the maximum of 

 A. Jiavicollis. In general form it is more slender than in the 

 related species, a peculiarity especially noticeable in the rostrum. 

 Brain-case longer and narrower than in A. sylvaticus, its upper 

 surface never developing lateral ridges, even in extreme old age. 

 Mandible slender, the coronoid process attenuate, short, noticeably 

 less developed than in the related species. Teeth as in Apodemus 

 sylvaticus. 



Measurements. — Average and extremes of ten adults : head 

 and body, 108-5 (103-114); tail, 102-4 (97-5-104); hind foot, 

 24-26-4 ; ear from meatus, 16-6 (16-18). For cranial measure- 

 ments see Table opposite. 



Specimens examined. — Twenty-three, all from Fair Isle (B.IM., U.S.N.M. 

 and Edinburgh). 



Remarks. — Notwithstanding its large size this species, like 

 Apodemus hebridensis and A. hirtensis, appears to be an offshoot of 

 A. sylvaticus rather than of A. jiavicollis. This is indicated 

 chiefly by the slenderness and lack of angularity of the skull, 

 the brain-case, even in excessively old individuals, always retain- 

 ing the smoothness of surface characteristic of the smaller animal. 



6. Fair Isle, Shetlands. N. B. Kinnear (c & p). 6. 5. 19. 1. 



{Paraiype of species.) 

 6 St. Fair Isle. N. B. Kinnear (c & p). 6. 11. 18. 1. 



2 <5, 1 9. Fair Isle. N. B. Kinnear (c & p). 6. 11. 18. 2-4. 



6, 2 9. Fair Isle. Duchess of Bedford 10. 10. 11. 1-3. 



(c & p). 



