CENSUS OF DISTRIBUTION OF BRITISH MOLLUSCA. 33 1 



S. rivicola (Leach). Thirteen counties. 



Eng. S. 6 21—23 32—34- Eng. N. 53 56 58 

 62 — 64 67. No records for Wales, Scotland, or Ireland. 

 S. ovale (Per.). Four counties. 



Eng. S. 17 21. Eng. N. 62 63. No records for 

 Wales, Scotland, or Ireland. 

 S. iacustre (Miill.). Twenty-one counties. 



Eng. S. 3 6 II 12 15 — 17 21 32 34 38. Wales 44 

 49 50. Eng. N. 56 61 — 64 66 67. No records for 

 Scotland or Ireland. 

 Palermo. 

 Pisidium amnicum (Miill.). Seventeen counties. 



Eng. S. II 13 22—24 29 38. Eng. N. 53 55 56 

 58 60 61 63 — 65 67. No records for Wales, Scotland, or 

 Ireland. 

 P. fontinale (Drap.). Thirty-two counties. 



Eng. S. o I 6 9 — II 13 17 21 32 — 34 38. Wales 

 4445. Eng. N. 53 56 58—67 69. Scot!. 73 90 108. 

 Irel. 124. 

 P. pusillum (Gmel.). Twenty-nine counties. 



Eng. S. o 6 9 II 13 14 16 17 21 23 26 32 33. 

 Wales 41 42 45. Eng. N. 56 61 — 64 66 67 70. Scotl. 73 

 81 90 107 108. No records for Ireland. 

 P. nitidum Jen. Fourteen counties. 



Eng. S. 6 10 16 23 38. Eng. N. 56 57 61 63 — 65 

 67. Scotl. 94 112. No records for Wales or Ireland. 

 P. roseum Scholtz. Three counties. 



Eng. S. 20 30. Eng. N. 56. No records for Wales, 

 Scotland, or Ireland. 

 Unio tumidus Phil. Twelve counties. 



Eng. S. 21—23 32 34. Eng. N. 53 55—57 61 63 

 64. No records for Wales, Scotland, or Ireland. 

 U. pictorum (L.). Thirteen counties. 



Eng. S. 6 17 21 22 29 32 38. Eng. N. 53 56 57 

 62 — 64. No records for Wales, Scotland, or Ireland. 



