lyS jnuRXAT. OF cDNCHOi.or.Y, voi,. i6. NO. 6, jriNE, 192T. 



Paludina {Vivipara) contecta. 26. Canals and slow rivers. 

 England mostly eastern, north to York M.W., introduced York 

 N.E. ; not in \Yales, Scotland or Ireland. 



P. vivipara. 42. Slow rivers, etc., in England generally north to 

 ^^orks. and west to Montgomery, Glamorgan and Devon S. in 

 canals ; dead shells Edinburgh and Limerick ; not in Ireland. 



Valvata piscinalis. 121. Running water and lakes north to 

 Aberdeen S. generally. 



V. macrostoma. 2. Running ditches Suffolk W. and Sussex E. 

 (^Proc. Malac. Soc, ix, 123; x, 42). 



V. cristata. 94. Slow streams, ditches, etc., north to Orkney: 

 rare in Scotland. 



Assiminea grayana. 3. Brackish water, Thames estuary and 



Suffolk E. 

 Pomatias {Cyclostoma) elegans. 46. Hedges and wild places on 



calcareous soil north to Westmorland ; holocene (?) in Channel 



Isles ; not in Scotland or Ireland. 



Acme {Acicula) lineata. 42. Local in old woods and wild places, 

 Kent E. and Devon N. to Renfrew ; more frequent in Ireland. 

 Doubtful in Somerset N. 



Neritina {Theodoxis) fluviatilis. 62. Rivers and canals, hard 

 arid soft water, south, east and central England, north to West- 

 morland ; central and west Ireland in calcareous districts. Its 

 outlying occurrence in Orkney is verified from about 1850 

 (E. Forbes in British Museum) to 1916 {^Proc. Malac. Soc, xiii, 

 151). Wants confirmation Cornwall W. and Devon S. 



Dreissena polymorpha. 38. Canals and rivers, Devon S. to 

 Perth S. : not in Ireland ; doubtful in Suffolk W. 



Unio pictorum. 44. Young parasitic on fish (as are the five 

 following species) : ponds, rivers, lakes and canals north to 

 Northumberland : not in Scotland or Ireland. 



U. tumidus. 38. Rivers, canals and lakes in England except 

 west, north to Yorks. ; not in Scotland or Ireland. 



Margaritana {Unio) margaritifera. 60. In soft water rivers 

 generally except in south, east and central England and central 

 Ireland. Wants confirmation in Dumfries and Shetland. 



Anodonta cygnea. 86. Ponds, rivers, lakes and canals north to 

 Elgin generally ; central Ireland. 



A. anatina. 54. Ponds, rivers and canals north to Edinburgh : 

 not in Ireland. 



