MILNE: CONTRIBUTIONS TuWARDS IRISH MOLLUSCA. 419 



Cochlicopa lubrica is almost as ubiquitous as P. umbilicata; 

 I have specimens from tlie Colony, from Annagh Bay, and 

 from the Warren ; also from Innisbiggle ; and sub-fossil 

 ones from the Warren. It keeps off the peat, however, 

 and is not so numerous either on the island or the main- 

 land, except at Westport, where the var. fusca is also found. 

 Alone of the shells found in the deposits, 



Clausilia rugosa has utterly vanished from Achill with the 

 trees; this commonest of Irish snails now stops where the 

 trees stop, at Molrhaney. 



Carychium minimum survives in vast numbers, though only 

 in one locality, with the Vertigos in the ditch at the Colony; 

 so that, though it is generally supposed to be a forest-loving 

 species, it seems to manage to withstand extermination. 



This ends the list of Achill shells, and I think there is 

 justification in it for concluding that a new fauna is takmg 

 the place of an old one. The destruction of the forests 

 has produced a change such that species like Clausilia 

 rugosa^ Helix netitoralis, and H. rotundata, and Zonites 

 nitidiis, Z. radiatulus, and Z. crystalliniis are dying out, 

 those that can accommodate themselves to changed con- 

 ditions — such as Zoniles alliarius, Pupa tcmbilicata, and 

 Cochlicopa lubrica — are meanwhile flourishing and filling 

 the land, and new immigrants more suited to the changed 

 soil — such as Helix aspcrsa and H. piilchella and Bulimus 

 acutics — are coming in to take the vacant places. If this 

 be at all true, it surely gives some light on the life of species. 



Table of Associated Species, 

 freshwater. 



L. peregra ... 



L. aun'ctilaria var. acuta 



ri.glabc-r 



L. feregra ... 



PL glaber 



r Lough Doo. 40 feet. 



\ Lough Nannljrach, 30 feet. 



