EASTERNESS AND ITS MOLLUSCAN FAUNA 107 



EASTERNESS: THE VICE-COUNTY AND ITS 

 MOLLUSCAN FAUNA. 



By W. Denison Roebuck, M.Sc, F.L.S. 



In my capacity as Hon. Recorder of the Conchological 

 Society of Great Britain and Ireland, I am endeavouring to 

 complete the census of distribution as based upon examples 

 authenticated by the Society's referees. I wish to call 

 attention to the vice-county of Easterness as one which has 

 been very little worked, and yet which is of high importance 

 from the point of view of distribution. Its situation in the 

 British Islands places it at about the point where the study 

 of the northern limitations of range offers problems worthy 

 of investigation ; and the remarkable rift valley along which 

 the Caledonian Canal runs constitutes an important feature 

 of the physical geography of the vice-county, and one likely 

 to have presented a formidable barrier to the northward 

 progress of various species. In altitude the vice-county 

 ranges from sea-level on the Moray Firth to over 4000 

 feet on the Cairngorm and Braeriach range, and it includes 

 the vast forest of Rothiemurchus, the scene of the re- 

 discovery of the long-lost species, Limax tenellus. It is 

 important, therefore, that a much closer survey of its land 

 and freshwater mollusca should be made than has hitherto 

 been done. 



The sketch-map given here shows the boundaries of the 

 vice-county. It may be defined as that portion of Inverness- 

 shire which lies east of the line of watershed between the 

 East and West of Scotland, to which is added Nairnshire, 

 and from which is subtracted a district which is included in 

 the vice-county called Elginshire, which is not quite the 

 same as the civil or political county of Elgin. It is needful 

 to explain that when Mr H. Cottrell Watson defined his 

 vice-counties, the civil county of Elgin consisted of two 

 detached portions, between which intervened a detached 



