I 3 2 



ANNALS OF SCOTTISH NATURAL HISTORY 



smoky musculits tint, but of a sepia-brown with a grizzled appearance 

 due to many of the hairs being tipped with rufous. The lower parts 

 of the hairs are exactly of the same shade as in Mus sylvaticus, for 

 a dark specimen of which, at a casual glance from above, the animal 

 might almost be mistaken. All these Mice even the very young 

 ones agree in presenting similar characters, and altogether are 

 quite the most distinct local form of Mus inuscitlus which I have 

 ever examined. 



In form and proportions these Mice are well-developed large 

 House Mice, only differing in this respect from ordinary Mice in 

 being above the average size. The dimensions of the series which 

 I have been able to examine are as follows (in millimetres) : 



9 skin (suckling : Coll. 

 G. E. H. B.-H. 



9 (spirit) ,, 



) J 5 ) )) 



if 5 ? 5 ) *> 



5 (spirit), suckling 

 + 5 ) 55 



< (juv.) (spirit) . 



9 (spirit), very young 



Head 

 and body. 



Tail. 



Hind 

 foot. 



Ear. 





17 14 



75 65 16 



52 

 65 



53 



52 



67 

 60 



14 



15 

 16 



1898. 



"| Brit. Mus. Coll., presented 

 / by Mr. J. Steele Elliott. 



/Brit. Mus. Coll., presented 

 10 J by the Kelvingrove Mu- 

 ( seum. 



10 1898. 



10 ^ Brit. Mus. Coll., presented 

 10.5 / by Mr. J. Steele Elliott. 



The arrangement of the mammae is as in Mus musculus, there 

 being ten pairs in all, of which three are pectoral and two inguinal. 



The skulls and dentition of these Mice are in general appear- 

 ance and size very musculus-Mke in character, but the triangular 

 narrowing of the internal opening for the nostrils is even more 

 strongly marked than in ordinary specimens of Mus musculus. 

 All the St. Kilda skulls possess this peculiar narrowed palate, a 

 character which I can only find in one out of over fifty specimens 

 of Mus iiiusciilus-VCkQ. Mice in the British Museum Collection, and 

 that one is a specimen of the subspecies Mus jalap cc (Allen and 

 Chapman) from Mexico. The greatest lengths of four skulls from 

 St. Kilda are 22, 22.5, 23, and 23 millimetres. 



It is obvious that, according to the custom of modern naturalists, 

 these two forms of Mice need new names. 



I therefore proposed the following names, leaving the question 

 as to the exact status of the two new forms to be decided when we 

 are in possession of a fuller knowledge of the other species or 

 subspecies of Mice of the respective groups. As to the desirability 

 of bestowing names on the two Mice from St. Kilda, I can have no 

 doubt whatever, but as to whether they are fit subjects for a 



