534 MURID^— APODEMUS 



island (p. 438), these mice have unusually long thick fur ; the back is 

 dark ; there is a pectoral spot and median wash of buff below — features 

 which are better developed in the male than in the female. The skulls 

 show greater palatal length, a wider masseteric plate, and longer molars 

 than in h. hebridensis ; but since the teeth are only slightly worn these 

 differences may be due to immaturity. The status of this animal 

 cannot be determined without further material. 



(2) A. hebridensis hamiltoni, Hinton. 



1914. Apodemus hebridensis hamiltoni, M. a. C. Hinton, Ann. and Mag. Nat. 

 Hist, July 1914, 126; described from Rum, Inner Hebrides; type specimen, 

 a male, No. 15.5.28.22 of the British Museum collection. 



Distribution : — Confined to the island of Rum. 



Description : — This field mouse agrees in general size and propor- 

 tions with the largest specimens of A. h. hebridensis, but has a still 

 larger and a more massive skull. Colour : — The backs are about as 

 in hebridensis ; the ventral surface is silvery, darkened by the hair- 

 bases, with an evident though not very bright pectoral spot, and some 

 slight trace of a yellowish wash ; the line of demarcation is a little 

 irregular, and moderately defined. The skull is distinguished from that 

 of h. hebridensis by its greater size, general narrowness (the nasals, 

 however, being as broad as in the Stornoway series), and greater 

 palatal length. The shoulders of the brain-case are rather strongly 

 ridged in a manner recalling the skull of A. flavicollis wintoni, from 

 which, however, it is readily distinguished by its much smaller bullae, 

 greater palatal length, and longer incisive foramina. 



For external and cranial dimensions, see tables at pp. 537 and 538 

 respectively. ^ 



(3) A. hebridensis cumbrce, Hinton. 



1914. Apodemus hebridensis cumbr^, M. A. C. Hinton, Ann. and Mag. Nat. 

 Hist., July 1914, 128; described from Great Cumbrae, Inner Hebrides; type 

 specimen, a female. No. 15.5.29.26 of British Museum collection. 



1913. Apodemus sylvaticus sylvaticus, G. E. H. Barrett-Hamilton and M. A. C. 

 Hinton, Proc. Zool. Soc, London, 1913, 835 (in part). 



Distribution : — The island of Great Cumbrae, Inner Hebrides. 



Description : — This mouse is smaller than typical hebridensis, in size 

 about as s. sylvaticus ; the tail and ears are relatively longer, the feet 

 relatively as large as in h. hebridensis. Colour of back rufous, with very 

 few black hairs ; the belly is silver, with hardly a trace of the pectoral 

 spot ; the line of demarcation is clear, but owing to the light colour of 

 the flanks, the contrast is not very striking. The skull is scarcely 

 larger than in j. sylvaticus, but it agrees in all essential respects with 

 that of hebridensis ; it differs from h. hebridensis in having the inter- 



