78 ME. G. E. H. BAERETT- HAMILTON ON [Feb. 7, 



through the flanks to the peppery reddish -brown of the upper 

 surface. 



All these peculiarities seemed to clearly point to a new species 

 or subspecies of Mouse ; but the animal having been in spirit, its 

 colour was regarded as unsatisfactory, and the unusual proportions 

 of its ears and tail were ascribed to individual variation. And so 

 the specimen was put on one side in the hope that in due time 

 further examples might be procured. 



Early in the spring of the present year I happened to come 

 across the specimen, and, being greatly struck by its remarkable 

 appearance, I at once endeavoured to procure some more of these 

 St. Kilda Mice, with the result that my friend Mr. Henry Evans, 

 during the course of a yachting cruise among the Scotch Islands, 

 put in at St, Kilda and landed some ti-aps for me ou the island. 

 Thanks to Mr. Evans, I have now before me, in addition to 

 Mr. Steele Elliott's specimen, a fine adult pair, male and female, 

 as well as a young female, of the St. Kilda Mouse, all sent down 

 in spirit. 



The dimensions, in millimetres, of these St. Kilda Mice are as 

 follows : — 



Head Hind 



and body. Tail. foot. Ear. 



S (skin : J. Steele Elliott. 1894 ; 1 o. or or 



Brit. Mus. Coll. no. 94.7.16.1) J °-^ ^"^ ^^ ~" 



J (skin : H. Evans, 1898 ; Coll. \ .(.J Ql oa-p. 17 



G. E. H. B.-H. no. 556) | ^^' ^^ ^^ ^' 



2 (spirit: ditto; ditto) 110 94 24 15 



5 ( „ juv.: ditto; ditto) ... 82 77 24-5 15-5 



They are thus remarkably large mice for typical Mus sylvaticus, 

 and the adults equal in size the largest measurements of the form 

 known as Mus flavicoUis Melch. The skull of the adult male is as 

 large an example as 1 have ever seen, reaching a total length of 

 29 mm. 



The following list of total lengths of the skulls of various 

 sylvaticus-Yike forms will illustrate this point : — 



mm. 



M.flavicolUs,^ S 29 Suffolk. 



6 28 (W. 264) Hereford. 



S 27 (W. 137) 



2 28 (A. 28) 



28 (W. 75) 



M. Tiehridensis, c? (type) . . 27 



if. sylvaticus (old) 26 (W. 10) 



„ (in general) . . 26 to 27. 



In form and proportions these mice resemble Mus hebridensis, 



^ The majority of these specimens have been placed at my disposal by my 

 friend Mr. de Winton, and the numbers appended are those affixed to them in 

 his collection. 



