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Class II. GASTEROPODA, OR UNIVALVES. 



Order Pectinibranchiata. 



Fam. Paludinidce. 

 BytUnia tentaculata, G. Ditch near the Water Works ; Rickerby Beck, 

 var. decolata, Thurstonfield Lough. 



Fam. Valvatidoe. 

 Valvata piscinalis, Mull. Ditch near the Water Works ; Petteril, Eden, 

 Rickerby Beck, Derwentwater. 



Order Pulmonobranchiata. 

 Fam. Lunnceidee. 



Planorbis nitidus, Mull. Very abundant. Ponds in the Willow Holme, at 



Rickerby, and at Blaithwaite. The specimens are most numerous 



in the pond in the Willow Hohne, and are very small at Blaithwaite. 

 P, nautileus, L. On dead leaves in a pond at Corby, in company with 



P. albus. 

 P. alius, MuU. Very abundant on dead leaves in a pond at Corby ; Moss 



Pool, Wreay ; and Thurstonfield Lough. 

 P. glaber, Jeffr. Very rare. The only locality I know where this shell is 



to be found is a pond at Blaithwaite ; and it is scarce there. 

 P. spirorbis, Mull. Tolerably common. Occurs in abundance in ditches 



near the Water Works, and at Rockliffe ; and in ponds at Rickerby 



and near Bassenthwaite Lake. 

 P. vortex, L. Somewhat rare. I have only found it in a ditch near 



Stanwix, where it is not by any means plentiful. 

 P. complanatus, L. Very abundant. This is the commonest species of 



Planorbis in this neighbourhood. It swarms in ditches near the 



Water Works, in Rickerby Beck, and in a pond near the Eden at 



Rickerby. On a bright day the animals rise to the surface of the 



water, and it is very interesting to watch them and P. spirorbis 



swimming about with their shells downwards. 

 P. coritortus, L. Not common. Derwentwater, Rickerby Beck, and in a 



ditch near the Water Works. 

 Physa hypnorum, L. Pretty well distributed. Ditches near the Water 



Works and at Rockliffe ; ponds at Rickerby and Blaithwaite. 

 P. fontinalis, L, Common. The finest specimens may be obtained in a 



stream near the Water Works. It is also found in Rickerby Beck. 

 Limnca ylulinosa, MuW. Pond near Windermere. (Bulwer.) 



