REPORT ON INVESTIGATION OF LAND MOLLUSCA 



'79 



highest importance. Indeed, as Dr R. F. Scharffhas pointed 

 out, the careful detailed and precise study of geographical 

 distribution in our islands tends to provide a key to the 

 solution of the greatest life problems, and has thus far- 

 reaching importance, and that the Mollusca as a group would 

 more than others as they are much better known as 

 regards their fossil history, structure, and phylogeny tend 

 to display the probable routes of dispersal, was suggested and 

 emphasised by the late Karl Semper, in which view other 

 distinguished students cordially concur. 



What is already known also tends to show the unlikelihood 

 of the multiple origin of the organisms of the British Islands 

 which was at one time suggested by Edward Forbes, and 

 points to the diffusion of life being based upon the dominance 

 of the more recently developed species, which by multiplication 

 and diffusion compel the migration or alternatively the 

 extinction of the earlier and competing forms of life. 



The problem before us was the accumulation of evidence 

 from the north of Scotland, a region which is so difficult 

 of investigation, by reason of its extent, its wildness and 

 desolation, and its being so devoid of population and means 

 of access from place to place, and where there have been so 

 few investigations, that a grant was asked for and acceded 

 to, for which our thanks are hereby tendered. 



The investigation was placed in the capable hands of Mr 

 Fred Booth, of Shipley, one of the keenest and ablest 

 conchologists of our acquaintance and he made a close and 

 careful examination of various selected localities on the Isle 

 of Skye, and in parts of the vice-counties of Westerness and 

 Ross West, on the western side of Scotland ; and of Aberdeen 

 North and South, and Kincardine, on the eastern side. At 

 the same time Mr J. Williams Vaughan, J. P., communicated 

 some results of a stay in Ross East. Mr Booth's account of 

 his work in detail has appeared in six instalments in this 

 Magazine for the present year. 



The results as far as they go are satisfactory, including 

 the addition of 12 species to the known authenticated fauna 

 of Ross West, 5 to that of Ebudes North (Isle of Skye), 

 17 to that of Westerness, 13 to that of Aberdeen North, 22 



