the smaller British Mammalia, 2*J\ 



place it was taken in traps set for vermin on broken rocky 

 ground at the base of the glens : it was also caught by the 

 dogs^ and knocked on the head by the shooters^ in the heathy 

 tracts up to the summits of the mountains ; and he adds, 

 which is worthy of remark, that, from want of speed, it was 

 much more easily killed than the common mouse or rat. 



The most striking peculiarity in this new species is its large 

 size compared with that of the A, arvalis. Both males and 

 females occur measuring five inches in the body without the 

 tail ; and it is said that they are sometimes met with five and 

 a half inches long, or even exceeding this. The following are 

 the relative proportions of a male specimen of medium size, 

 according to Mr. Thompson : — 



in. lin. 



Head and body 5 



Tail to end of bone 1 3 



Tail to end of hair 16 



Head 1 7J 



Ears 5 



Whiskers 1 



Forefoot 5| 



Hind-foot 10 



A female of the same size preserved the same relative mea- 

 surements, excepting that the hind foot was shorter by half 

 a line. I observe, amongst the specimens he has sent myself, 

 that the males have generally the feet and tail somewhat 

 larger and stouter than the females. The same thing, how- 

 ever, occurs to a less degree in the A, arvalis. 



As regards external form, including the characters of the 

 snout, eyes, ears, feet, toes, and tubercles on the soles, it is 

 similar to the common species. In each also there is the 

 same' number of mammae, four pectoral and four inguinal*. 



The general colour of the upper parts is also the same ; but 

 the fur is everywhere considerably longer, so as to cause the 

 ears to be entirely concealed ; and its greater length, as well 

 as the greater quantity of it, is especially obvious on the under 

 parts, where it is also darker at the roots, and of a rather 

 purer white at the tips of the hairs. Some specimens are 

 more rufous above than others ; but the brightness of the tint 

 appears to have no constant connexion with the sex or size of 

 the individual. The colour of the feet and tail, in all cases, is 

 dusky ; the latter somewhat darker above than below, as in the 



* This is of importance to be noted, since in the A. suhterraneus of De 

 Selys, a closely allied species found in Belgivim and France, and possibly to 

 be met with in this country, the number of mammae is only sixj all of which 

 are inguinal. 



