Clare Island Survey — Land and Fresh-water Mollusca. 23 37 



near the close of the first day's work that I found Clausilia bidentata alive — 

 a single shell on the cliffs of the great sea-gully at Alladoon, opposite 

 Inishshark. On the following day it was taken sparingly on the cliffs east 

 of Doonahineena. 



Balm perversa occurred on the south-east angle of the mortared wall 

 enclosing the graveyard. Acicula lineata figures in G. P. Farran's list, but 

 was not seen by rne, though several likely spots were carefully searched for 

 it. The habitats for the fresh-water species are as follows : — 



Lough Fawna — L. pereger, P. obtusale. 



Loughnabraud — Z. pereger and PL crista. 



Loughnagrooaun — L. pereger, P. obtusale. 



Lough Gowlanagower — L. pereger, P. pusillum, P. hibernicum, -and 

 P. milium. 



Church Lough — L. pereger, L. palustris, PI. crista (in the outlet), 

 P. subtruncatum, P. milium, P. casertanum. 



Stream in the meadow-land at Cloonamore — PI. spirorbis, Pisidium 

 subtruncatum, P. pusillum, P. nitidum, and P. milium. 



Several other streams and pools contained P. casertanum and P. milium. 

 Lough Bonn was found to be too salt to contain any fresh- water species. 



The best find on Inishbofin was undoubtedly Pisidium hibernicum. This 

 bivalve, unknown up to the present outside Ireland, has hitherto been taken 

 only in three small alpine tarns, one in South Kerry and two in West Cork. 

 I have suggested to Mr. B. B. Woodward that it may be an American species, 

 but so far he has failed to recognize it among the species described from 

 that continent. 



Taken as a whole, the molluscan fauna of Inishbofin strikes me as being 

 rather more closely related to that of the mainland of West Galway than to 

 that of either Inishturk, Clare Island, or Achill Island, though on paper the 

 lists of species from these districts will be found to be similar. 



LOUISBURGH. 



This may be regarded as the richest district in mollusca of all those 

 included in the survey, for of the eighty-eight species so far recorded for 

 West Mayo, seventy are to be found living within its boundaries. The 

 absentees are mainly fresh-water species, which have a more or less strictly 

 central distribution in Ireland, and do not extend their range beyond the 

 districts of Westport or Castlebar. The great stretches of highly calcareous 

 sand-dunes between Louisburgh and the entrance to Killary Harbour contain 

 many lakes, in which, besides the usual western fauna, represented by shells 



