ROF.IUTCK MF.MOKIAI. NUMUKR. I79 



Pseudanodonta s[). 5. Rivers and canals ; species indeterminate, 



those from Thames said to be P. eloiigata {^Proc. Alalac. Soc.^ ix, 



III ; Journal, xiii, 138) those from W^orcester, Warwick and Stafford 



[Journal, xiii, 274: Proc. Malac. Sac, xii, 209) P.rothoniagensis. 

 Sphaerium rivicola. 32. Local in rivers and canals south and 



(^entral England to Yorks. ; not in Scotland or Ireland : wants 



confirmation in Northumberland S. 

 S. corneum. 131. Ponds, streams, etc., generally. 

 S. lacustre. 93. Ponds, sometimes temporary, and stagnant 



water, rivers and canals north to Ross ; not common in Scotland 



and Ireland. 

 S. pallidum {ovale). 12. Rare in canals and associated waters, 



Northampton and .Ciloucester to Montgomery and Yorks. ; 



formerly in Surrey and Middlesex ; dead shells in Bucks. 

 Pisidium amnicum. 95. Running water generally, lowland lakes 



and meres north to Perth M. 

 P. casertanum. 113. Ubiquitous. 

 P. henslowanum. 64. Running water, lakes and ponds generally 



north to Lanark. 

 P. hibernicum. 68. Ponds, streams, lakes, etc., generally {Irisli 



iVal.. \xvii, 33). 

 P. lilljeborgi. 26. Mountain lakes, north-west England, Wales, 



Scotland and Ireland. 

 P. milium. 100. Ponds, rivers, canals, etc., generally. 

 P. nitidum. 108. Ponds, rivers, lakes, etc., generally. 

 P. obtusale. 90. Ponds and stagnant water generally. 

 P. parvulum. 20. Rivers and canals, Middlesex and Wilts, to 



Montgomery and Yorks. and in north and south Ireland. 

 P. personatum. 88. Stagnant water, puddles and temporary 



ponds generally. 



P. pulchellum. 49. Ponds, streams and canals generally. 

 P. subtruncatum. 112. Ponds, rivers, canals, etc., generally. 

 P. supinum. 21. Rivers and canals, Surrey and Somerset to 



Yorks. : not in Wales, Scotland or Ireland. 

 P. tenuilineatum. 4. Rivers and canals, Berks., Oxford, Bucks., 



and Northampton [Journal, xv, 296). 



