Stklfox — List of Land and Freslmater Mollusks of L' eland. 125 



widely distributed throughout the main- 

 land. Has also been taken on Clare 

 Island and Achill Island in West Mayo. 



Pisidium casertanum Poli. 



? Pisidium cineretim, Thompson, Cat. L. 

 & F. W. Moll, of Ireland, p. 40, 1840. 



WD ED LD AH 



FE TY AE DO 

 WMSL LE MO 



EM KO CV LH 

 WGNC LP WHME 



SG EC KD DU 

 CL NT QC CWWI 

 NK LK ST KK WX 



SK MC EC WA 



wc 



Very generally distributed. The 

 P. pusillum var. grandis of most 

 English authorities. In peat-bogs, 

 ditches, and pools of peaty water this 

 species and P. personatum are particu- 

 larly abundant, and are often to be 

 found where no other shell can appa- 

 rently live. In the lakes of West 

 Mayo a peculiar form of this species 

 occurs ; and specimens sent to Mr. B. B. 

 Woodward were at once recognized by 

 him as a lacustrine form. 



Pisidium obtusale Pfeiffer. 



Widely distributed, but is a somewhat 

 local shell. Occurs on some of the 

 western islands. On the Dingle pro- 

 montory, in South Kerry, this species is 

 very abundant in some of the mountain 

 tarns, and occurs in the Coomb-a-knock 

 Lake on Brandon Mountain, up to an 

 altitude of 2300 feet. 



WD ED LD AN 



FE TY AK DO 

 WMSL LE MO 



EM RO CV LH 

 WGNC LF WHME 

 SG KC KD DU 

 GL NT QC CW WI 

 NK LK ST KK WX 

 SK MC EC WA 

 WC 



Pisidium nitidum Jenyns. 



WD ED LD AN 



FE TY AR DO 

 WMSL LE MO 



EM RO CV LH 

 WG NG LF WHME 



SG KC KD DU 



CL NT QC CW WI 

 NK LK ST KK WX 



SK MC EC WA 

 WC 



Generally distributed, but, like P. 

 pulclieUum and P. obtusale, is local and 

 often absent from large areas. Like the 

 other members of the genus, this shell 

 is frequently met with on the western 

 islands. It is also frequently common 

 in mountain tarns, which liave stony 

 bottoms, with little vegetation. 



Pisidium pusillum (Gmelin). 



Generally distributed on the main- 

 land, and is also found on some of the 

 islands. The old records for this shell 

 probably include both the next S2}ecies 

 and P. obtusale. 



