Freshwater Mollusca of Ireland. 



195 



gland likewise, the additional habitat of Stow Pool, Lichfield, may 

 be given, where I procured it in July, 1836. 



Gen. 2. Pisidium, Pfeiffer. 



1. P. obtusale\, Pfeiffer ? Jenyns, Monog. p. 13. pi. 20. f. 1—3 ; 



Gray, Man. p. 282. pi. 12. f. 149. 

 This, with the exception of P. Henslowianum, would seem to be 

 the rarest of the Pisidia in Ireland. In two localities in the county 

 of Down it has occurred to me — in a drain cut through clay soil in 

 a brickfield near Bangor, and in a pond at Portavo, the seat of D. 

 Ker, Esq. M.P. A single specimen has been taken at Finnoe (county 

 Tipperary) by Edw. Waller, Esq. 



2. Pisidium nitidum, Jenyns, Monog. p. 16. pi. 20. f. 7, 8 ; Gray, 



Man. p. 283. pi. 12. f. 150. 

 Is somewhat generally distributed in Ireland. It is abundant in 

 a cold turfy deposit conveyed by a mountain stream to a pond at 

 Wolf hill I near Belfast ; and on the Utricularia vulgaris growing in 

 stagnant pools, excavated in brick-making close to the town — these 

 places are of a very different nature, the pond at the former being 

 supplied with clear spring water, and at an elevation of nearly 600 

 feet above the sea, the latter but a few feet above it, and supplied 

 only with rain water. In the west, I have obtained this species in 

 Lough Gill, county Sligo. From about Portarlington it has been 

 sent me by the Rev. B. J. Clarke, and from Finnoe by Edw. Wal- 

 ler, Esq. 



3. Pisidium pusillum, Jenyns, Monog. p. 14. pi. 20. f. 4 — 6; Gray, 



Man. p. 283. pi. 1. f. 7. 

 Is the most common of the genus in Ireland, and universally dis- 

 tributed. It is generally to be met with in ponds, drains, &c. ; but 

 in marshy spots, both in this country and in Scotland, I have found 

 it in company with, and adhering to, the same stones as land Mol- 

 lusca which inhabit such places, as Vertigo palustris, &c. In the 

 north and south of Ireland I have procured it among moss, which 

 was kept moist only by the spray of the waterfall. 



4. Pisidium pulchellum, Jenyns, Monog. p. 18. pi. 21. f. 1 — 5§ ; Gray, 



Man. p. 284. pi. 12. f. 15L 

 This handsome and well-marked species is generally distributed 

 over the island. It inhabits stagnant and running water of the least 

 as well as greatest extent, and at the same time and place may be 

 found on various subaquatic plants, and buried in the mud — the 

 largest and finest specimens I have procured were from the gently 

 flowing river Main, near its junction with Lough Neagh. 



f All the Pisidia about to be noticed, have been determined from compa- 

 rison with English specimens favoured me by the Rev. L. Jenyns and Mr. 

 Alder. 



% A minute leech preys much on the P. nitidum and P. pusillum, which 

 are found here in company. 



§ All the varieties are found in Ireland — of var. 3, a single specimen 

 has been obtained by the Rev. B. J. Clarke near Portarlington. Mr. Jenyns 

 is now inclined to consider this a distinct species. See Gray, Man. p. 285. 



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