102 HISTORY OF THE EUROPEAN FAUNA. 



divided the British Islands into ten districts, accord- 

 ing to the distribution of their molluscan fauna. 

 These are 



I. The Channel Isles. 

 II. South-east of England (including Cambridgeshire). 



III. South-west of England. 



IV. North-east of England. 



V. North-west of England (including Isle of Man). 

 VI. North of Ireland. 

 VII. South of Ireland. 

 VIII. South of Scotland. 

 IX. North of Scotland. 

 X. Shetland Isles. 



In a short paper on this subject (b, p. 5), I have 

 shown that some of these districts are founded on 

 erroneous data, whilst, with the knowledge now at 

 our disposal, others can no longer be maintained as 

 distinct. I thought then that the molluscan fauna 

 warranted a division of the British Islands into the 

 following two provinces : 



I. England and Wales (except the South-west). 

 II. South-west of England and Wales and the whole of 

 Ireland and Scotland. 



The second district contains some species of mol- 

 luscs which are almost entirely absent from the first, 

 such as Geomalacus maculosus, Testacella Maugei^ 

 Helix piscina, Helix revelata, Helix acuta, and Pupa 

 ringens. These are all of Lusitanian origin, and do 

 not occur in Central Europe. Scotland alone cannot 



