MOLLUSCS 



Limntea glabra (Mtill.). Very rare : two speci- 

 mens have been found near Derby 



Planorbts corneus (Linn.). Plentiful in all the 

 canals in the south of the county 



a/bus, Mull. Common in the south of 



the county 



g/ater, Jeff. Cresswell Crags, in rejecta- 



menta ; pits at Wellington 



nauti/eus (Linn.). Cresswell Crags, in 



rejectamenta 



carinatus, Mttll. Derby ; Clifton 



marginatus, Drap. Derby 



vortex (Linn.). Derby ; Clifton 



spirorbis, Mttll. Derby 



contortus (Linn.) 



fintanus (Lightfoot). Marple ; canals at 



Derby ; Cromford canal 

 Physa fontinalis (Linn.) 



Physa bypnorum (Linn.). Rare : canal at Little 

 Eaton ; Darley Dale ; river Dove, 

 near Repton 



Bithynia tentaculata (Linn.) 



leachii (Shepp.). Canals at Weston-on- 



Trent ; Eggington ; Shardlow 

 Vvulpara vivlpara (Linn.). Canals round Derby 



contecta (Millet). Rare : two specimens 



in canal at Wellington ; one in the 

 canal at Cromford 



Valvata piscina/is (Mttll.). Derby ; Crom- 

 ford ; two reversed specimens were 

 found at Cresswell 



cristata, Mttll. Eggington ; Derby 

 Achilla lineata (Drap.). Cresswell Crags in 



rejectamenta 

 Neritina fluviatilh (Linn.). Canals at Bor- 

 roughash ; Sawley ; Pyebridge 



B. PELECYPODA 



Dreissensia polymorpha (Pall.). Derby and 

 Nottinghamshire canal ; Willington 

 canal ; Butterley 



Unio pictorum (Linn.). Derby, in canals 



tumidus, Retz. Canals round Derby ; 



Repton, where a specimen was found 

 measuring 4f x 2f in., and weighing 



4i z - 

 Anodonta cygntea (Linn.). Plentiful in canals 



round Derby 

 Sphesrium rivicola (Leach). Canal between 



Shardlow and Chellaston ; Cromford 



corneum (Linn.) 



Sphcsrium ovale (Fdr.). Peak Forest canal ; 

 one specimen in the canal near Sawley 

 at its junction with the river Trent 



lacustre (Mttll.). In canals at Derby and 



Ambergate 

 Pisidium amnicum (Mttll.) 



pusillum (Gmel.) 



nitidum, Jenyns. Cresswell 



rejectamenta 



fontinale (Drap.). River Wye 



Dale and Monsall Dale ; 

 Clifton ; Matlock 



milium (Held). Clifton 



Crags, 



in 



Ash wood 

 Stanton ; 



53 



