ALSTON'S BANK MOUSE 



423 



Description: — It is a quite distinct form of comparatively large size, 

 but with relatively short ears and tail, and peculiar skull. 



In general size it approaches norvegicus, being larger than glareolus 

 but smaller than skomerensis. The tail and ears are about as in glareolus, 

 the hind feet about as in norvegicus or skomerensis. 



The colour is similar to that of adults of the deeply-tinted forms of 

 glareolus, being deep " russet " above, the under-side richly washed with 

 yellowish or buffy tints. 



The skull is larger than in glareolus, and agrees in size with that of 

 norvegicus, as it does also in the heavy jugals, although the curvature 

 of the zygomata is similar to that oi glareolus. The brain-case is very 

 broad and smoothly convex, the temporal ridges being but faintly 

 indicated even in aged skulls, and the parietal region in dorsal profile 

 is not flattened but convex, with the highest point a little behind the 

 middle of the parietals ; these features impart an appearance of rela- 

 tively greater cranial capacity than is seen in any other European 



DIMENSIONS IN MILLIMETRES:— 



species of Evotomys. The squamosal post-orbital processes are not con- 

 spicuous. The inter-orbital region is broad, with a wide shallow median 

 sulcus. The nasals are rounded or slightly and narrowly emarginate 

 behind; they end flush with or slightly behind the ends of the pre- 

 maxillaries, and are slightly longer than the diastema ; they are 



macgillivraii, M. a. mial, and M. a. Ittch) \ in all, of six new forms. The work 

 resulted in very material additions to our knowledge of the distribution of British 

 mammals, and, in particular, of the relationships and classifications of the difficult sub- 

 family of Microtittce, and has thrown much light on the origin of the recent British 

 fauna. The collections made included 280 specimens of 1 1 species, and have been 

 described by myself and Hinton in Proc. Zool. Soc. (London), 1913, 821 ; and 

 Ann. Mag. Nat. Hist, October 1913, 361 ; a further paper is in contemplation. 



It may safely be said that no collection of British mammals has ever approached 

 the present one in importance. 



