MOLLUSCS 



II. PROSOBRANCHIATA 



Paludestrina jenkinsi (Smith). 



— ventrosa (Mont.). Dead 



at Southport 

 BUhynta tentaculata (Linn.) 



— leachli (Shepp.) 

 Vivipara v'w'tfara (Linn.) 



Droylsden 



specimens, sparingly. 



Vivipara contecta (Millett) 

 Valvata piscinalis (Mull.) 

 — cristata, MuIl. 

 Pomatias elegans (MuIl.). 



Carnforth 

 Acicula lineata (Drap.). 



around Manchester ; Preston 

 Neritina fluviatilis (Linn.) 



Between Grange and 

 Fleetwood ; Grange ; 



B. PELECYPODA 



Dreissensia polymorpha (Pall.) 

 Unio pictorum (Linn.) 

 ■ — tumidus, Retz. 



— tnargaritifer (Linn.). Gibertson (Alder Collec- 



tion) ; River Lune at Caton (Dyson) 

 Anodonta cygno'a (Linn.) 

 Spharium rivicola (Leach) 



— comeum (Linn.) 



— ovale (F^r.) 



— kcustre (Mull.) 

 Pisidium amnicum (MuIl.) 



— pusillum (Gtnel.). Near Silverdale, where also 



the variety P. obtusak, now held by some 

 to be a distinct species, is found in a Shell- 

 marl. 

 Pisidium nitidum, Jenyns. 



— fontinale (Drap.). Common : the var. Hen- 



slomana has been found near Preston and 

 near Manchester, and the variety P. pul- 

 chellum occurs in a Shell-marl near Silver- 

 dale. 



— milium (Held.). Bardsley and neighbour- 



hood 



99 



