110 



Proceedings of the Royal Irish Academy. 



forms of this shell occtir, each tam 

 haTing a distinct form of its own. In 

 some instances shells from these 

 localities even approach Limnaea iiieoluia 

 or i. praetenuU in shape and ia texture, 

 and are almost as ■worthy of specific 

 rank as the two shells just mentioned. 



Limnaea inyoluta Harvey. 



Plate TU, fig. 9. 



Limnem intohdm, Thompson, Cat. L. & 

 F. "VT. Moll, of Ireland, p. 31, 1840. 



WD ED LD AN 



FE TT AE DO 

 WMSL LE MO 



EM EO CV LH 



WGXG LF WH:ME 



SG EC ED DU 



GL NT QC CW \a 



NK LK ST EE "WX 



SE MC EC WA 



wc 



For over half a century Lough Crin- 

 caum on Cromaglaun Mountain in 2f orth 

 Kerry was considered the only habitat of 

 this interesting Limnaea ; but, since the 

 finding of the next species in a similar 

 isolated lough, Mr. Phillips has taken 

 this shell in Barley Lake above Glen- 

 garriff in West Cork. It is more than 

 probable that it also occurs in others of 

 the hundreds of small tarns which are 

 scattered over this comer of our island. 



Limnaea praetenuis, BoweU. 



Plate VII, fig. 7. 



Limnaea sp. ? Stelfox and MUne, Irish 

 XaturaUst, p. 288, 1907. 



Since its discovery in South Xerry in 



Lough Kagarriva, the haMtat of 

 Puidium Tiibernieam, the range of this 



T\"D ED LD AX 



FE TY AE DO 

 WMSL LE MO 



EM EO CV LH 

 WGXG LF WHME 

 SG EC ED DU 

 CL NT QC GW WI 

 XE LE ST EE WX 

 SK MC EG WA 

 WC 



shell has been greatly enlarged owing 

 to some dredging which has been carried 

 out in the lakes of Fermanagh and the 

 southern portion of East Donegal by 

 Major Trevelyan. From Lough Derg 

 in the former division and from Lough 

 Vearty and other neighbouring lakes in 

 Fermanagh this collector has forwarded 

 specimens to the Rev. E. "W. Bowell, 

 who, on examining their anatomy, lias 

 referred them to this species, of which 

 he was the original describer. 



In the peaty lakes of Achill Island and 

 on parts of the mainland of West Mayo 

 very similar shells are met with (fig. 8), 

 but whether they are referable to this 

 or to another new species, or are 

 only aberrant forms of Limnaea pereger, 

 I cannot at present say. It is well 

 to observe that neither this shell nor 

 Limnaea involuta has ever been taken 

 associated with any recognized form 

 of L. pereger, and moreover that in 

 the lakes in which they occur, the 

 water has always beeu to a great 

 extent peaty. These two important 

 facts might be used as arguments 

 against the specific distinction of these 

 shells; but for the present 1 suppose 



