728 RODENTIA— MURID^ 



castaneus, but its colour pattern is modified somewhat so as to make 

 an approach towards that of 5. grantii. 



Neomys fodiens bicolor (Shaw). 



From Skye we received five specimens collected in June and July 

 by Mr C. H. B. Grant. These differ in no way from the Water Shrew 

 of the mainland. 



RODENTIA. 



MURID^. 

 THE FOULA FIELD MOUSE. 



APODEMUS FRIDARIENSIS THULEO, Hinton. 



1919. Apodemus fridariensis THULEO, M. A. C. Hinton, Scottish Naturalist, 

 November and December 1919, p. 177, described from the Island of Foula ; type, 

 an adult female, collected November 1917 (original No. 5.). 



Distribution : — Foula (the Ultima Thule of Tacitus). 



Description : — In general external appearance this animal closely 

 resembles typical fridanensis, but differs in its smaller size and larger 

 hind-feet. 



Size small, the head and body measurement being scarcely greater 

 than in A. sylvaticus, and therefore considerably less than in A. f. 

 fridariensis. The tail is about equal to the head and body in length 

 when all the specimens in adult pelage are averaged ; but it is slightly 

 shorter relatively in the larger or older specimens. The hind-foot 

 is very large, its absolute size being as great as in the St Kilda Field 

 Mouse, A. hirtensis, while its relative size is larger than in any other 

 British form. The sole-pads are small as in typlcaX fridariensis. 



In colour the Foula Field Mouse agrees exactly with typical 

 fridariensis. The flanks are dark, the lateral line of demarcation 

 being regular and sharply defined. The ventral surface is of a 

 dull bluish white, without any trace of a buffy suffusion. Normally 

 there is no trace of a pectoral spot. The tail is strongly bicoloured, 

 dusky above, white below. Dorsal surfaces of the feet white. 



A direct comparison of the skulls suggests a closer affinity between 

 A. f. thuleo and A. f. grantii than between the former and true 

 fridariensis. The bulljE are as small, and the masseteric plate projects 

 as little anteriorly as in grantii ; while the brain-case appears to be 

 still broader, rounder and more depressed than in the latter sub-species. 

 In the mandible the coronoid process is very feebly developed as in 



