43 



It inhabits Jakes, rivers, canals, and ditches, mostly 

 on aquatic plants ; it can also live under the influence 

 of a tide, where the water is brackish, as it is found in 

 the Greenwich Marshes, associated with Assiminia 

 Greyana j the latter is a shell which is only to be pro- 

 cured in brackish rivers in the south of England. 



It lays about a dozen eggs, which it attaches to the 

 stems of submerged leaves of aquatic plants. 



Our localities are, a small ditch between the canal 

 and main line of railway at Lenton, where it is abun- 

 dant, but only spread over the space of about 20 yards ; 

 under the Seven Arches in the Nottingham Meadows, 

 tolerably abundant; and, rare, in a ditch near the 

 Trent, between Beeston and Atlenborough. Mr. Jef-' 

 freys, of Swansea, has also found it in Clumber Lake. 



Other localities are, Penzance, Cornwall (Millelt), 

 near London (Grey), Devonshire (Montagu), South 

 Wales (Jeffreys), Essex (Sbeppard), Preston (Kenyon), 

 Bath (Clark), many tributaries of the Thames (Forbes), 

 Cardiff (Jeffreys), Scarborough [rare] (Bean), Surrey 

 (Millett), Battersea (Brown), and Suffolk (Grey). 



In France, it is found at Tailes (M. N. Boubee). 



I believe it has not been discovered in Ireland or 

 .Scotland. 



As a foss it ranges as far back as the oolitic period 



(Forbes). 



Valvata. 



These shells are conical, twisted, arid rather fragile. 

 The convolutions are smooth and very rounded, and 

 they are umbilicated. They have a circular aperture, 

 with a continuous peristome, and the aperture pro- 

 tected by a horny operculum. 



