544 



MURIDiE— APODEMUS 



(2) Apodemus fridariensis grantii (Hinton). 



1914. Apodemus fridariensis grantii, M. A. C. Hinton, Ann. and Mag. Nat. 

 Hist, July 1914, 132 ; type an old male, No. 15.5.31.4 of British Museum collec- 

 tion ; described from the island of Yell, Shetland. 



Local name : — Hill Mouse. 



Distribution : — Yell, and possibly Mainland, Shetland. 



Description: — This sub-species is distinguished from typical A. 

 fridariensis by its slightly smaller size and relatively shorter tail. In 

 colour it is quite like the typical form, save that a small pectoral spot 

 appears to be constantly present, and the contrast between the upper 

 and lower surfaces of the tail is much less striking. The line of 

 demarcation on each flank is very regular and distinct. 



The skull is slightly smaller than in the Fair Isle form. The 

 brain-case is shorter and rounder, more like that of sylvaticus in form ; 

 the nasals slope more gently forwards, and the dorsal profile appears to 

 be flatter and less convex throughout. The masseteric plates of the 

 zygomata are much narrower and do not project so far in advance of the 

 bridges over the infra-orbital canals. The bullae are smaller. In the 

 mandible the coronoid processes are even more slender; the angular 

 processes are exceptionally long, and specimens may be readily dis- 

 tinguished by this character from the mandibulae of all other European 

 forms of Apodemus. For external and cranial dimensions, see tables 

 below and at p. 538 respectively. 



DIMENSIONS IN MILLIMETRES:— 



