332 CENSUS OF DISTRIBUTION OF BRITISH MOLLUSCA. 



U. margaritifer (L.). Ten counties. 



Wales 45 49 50. Eng. N. 62 67 71. Scotl. 90 

 107. Irel. 126 145. No records for England South. 



Anodonta cygnea (L.). Twenty-one counties. 



Eng. S. 20 22 — 24 30 32 33 38. Wales 42 45. 

 Eng. N. 53 55 56 58 59 61—64 67. Scotl. 90. No 

 records for Ireland. 



A. anatina (L.). Thirteen counties. 



Eng. S. 15 16 21 22 32. Wales 45. Eng. N. 56 

 61 — 65 67. No records for Scotland or Ireland. 



Dreissena polymorpha (Pall). Twelve counties. 



Eng. S. 17 21—23 29 31 32 40- Eng. N. 56 58 63 

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



Neritina fluviatilis (L.). Eighteen counties. 



Eng. S. 6 II 13 14 16 21 — 24 29 32. Eng. N. 53 

 56 57 60 62 64 65. No records for Wales, Scotland, or 

 Ireland. 



Palermo ; Algiers. 

 Paludina contecta (Millet). Fifteen counties. 



Eng. S. II 22—24 27 29 31 32. Eng. N. 53 54 58 

 59 61 63 64. No records for Wales, Scotland, or Ireland. 



P. vivipara (L.). Seventeen counties. 



Eng. S. 17 20—23 31—34 38. Eng. N. 53 55-57 

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



Bythinia tentaculata (L.). Thirty-five counties. 



Eng. S. 5 6 10 II 15 — 17 20—24 29 30 32 — 34 38 

 39. Wales 41. Eng. N. 53 — 58 60 — 67. Scotl. 76. 

 No records for Ireland. 



Bordeaux ; Cologne ; China. 



B. Leach ii (Shepp.). Seventeen counties. 



Eng. S. 6 II 14—16 21 23 32—34. Eng. N. 53 

 56 57 60 — 64. No records for Wales, Scotland, or 

 Ireland. 



Bordeaux ; Sarno R., Sicily. 



J.C, iv., July, 1885. 



