B. -Hamilton — Addition to List of British Boreal Animals. 319 



considered to have definite relations to the peculiarly cramped local 

 conditions of a small island. On the contrary, the Skomcr Vole is 

 remarkably robust, and apparently only slightly less so than the 

 corresponding types of Boreal Europe. In its robustness it affords a 

 parallel to. the long-tailed Field Mice of St. Kilda and of Lewis {Mus 

 sylaticus Mrtensis milii and M, helridensis, de "Winton), and the H ousc 

 Mouse (Jf. muralis mihi) of the former island. 



It cannot, however, be without meaning or importance that we 

 have here on this small, treeless, wind-swept islet, almost facing the 

 home of Lepus timidus hibernicus, an animal which belongs to the same 

 type of Fauna as that Boreal mammal. It may be that we may yet 

 find amongst the Welsh mountains further colonies of these Boreal 

 Yoles, and the possibility should at least be a stimulus to British 

 Field JS'aturalists in their collecting expeditions. Meanwhile we may 

 note the parallel between the occurrence of a Boreal Yole at sea-level 

 on Skomer Island and the similar downward extension of the range of 

 the Yariable Hare in Ireland, accompanied as it is in the West by 

 the frequent descent to the plains of certain Alpine plants. 



R.I.A. PROC, VOL. XXIV., SEC. B.] '^ ^ 



