102 



Proceedings of the Royal Irish Academy. 



■white form occurs sparingly in several 

 of the northern deposits, but is fairly 

 common in those round the north-west 

 coast of Donegal. The old records for 

 this species from Limerick, South Kerry 

 and " Co. Cork " require verification. 



Vertigo angustior Jeffreys. 

 WD ED LD AN 



FE TY AR DO 

 WMSL LE MO 



EM EO CV LH 



WG ^'G LF WH ME 



SG KG KD DU 



CL NT QC CW ^'I 



NK LK ST KK WX 



SK MC EC WA 



wc 



Like the last species, this appears to 

 have become extinct iu many of its 

 former habitats, probably owing to 

 blown sand fiUing and drying up its 

 dwelling-places, which are as a rule 

 coastal marshes. It is widely distri- 

 buted over the southern, western, and 

 northern districts, but seems to avoid 

 the central plain and the eastern 

 counties.' In the west it has recently 

 turned up in great abundance in several 

 isolated localities, similar to that in 

 Sligo near Ballina, where Miss Warren 

 has collected it for many years. 



CLAUSILIIDAE. 



Balea perversa (Linne). 



Like Limax arhorum, this species 



' Messrs. Taylor and Eoebuck give a record 

 for this species from Co. Cork, but it is impos- 

 sible to say to which division this should be 

 referred. 



flourishes in the bare and open parts of 

 the country, as well as in the old 



WD ED LD AN 

 FE TY AR DO 



WMSL LE MO 



EM RO CV LH 

 WG NG LF WH ME 

 SC KG KD DU 

 CL NT QC CW Wl 

 NK LK ST KK WX 

 SK MC EC WA 

 WC 



wooded areas, and shows no real pre- 

 ference for any geological formation, 

 being almost as common on non-cal- 

 careous rocks as on the Chalk or 

 Carboniferous limestone. The hardiness 

 of this shell is remarkable, and perhaps 

 none of our land mollusca is found 

 under such variable conditions. It is 

 a species which has constantly to with- 

 stand the hottest summer sun in man)- 

 of its habitats, and yet I have often 

 seen it on the crawl during frosty 

 weather. In the central counties it is 

 frequently associated with Pupa cylin- 

 dracea and Pyramidula riipestris on the 

 limestone walls ; on the cliffs of Clare 

 Island in West Mayo it is found with 

 Hygromia fusca, Pupa anglica, Acicula 

 Imeata, and Limnaea truncatula ; whUe 

 in the wooded districts it has often 

 other companions. Yet in spite of the 

 remarkable adaptability of this shell, it 

 shows no variation of any importance ; 

 and if the shells from several districts 

 were thrown together, I doubt if anyone 

 could separate them. Throughout the 

 mainland it is generally distributed ; 

 and it is also usually met with on the 

 adjoining islands. 



