lo2 



Better known by some as the Ancylus lacustris of 

 Muller, Tiiiton, Thompson, Brown, Draparnaud, Isilson, 

 &c.; by others, as the Patella ohlonga of Lightfoot, 

 Donovon, &c. ; and by others, as the Patella lacustris 

 of Montagu, and the Valletia lacustris of Grey. 



Very fragile, thin, and much elevated; length- 

 ened oblong form, with the side compressed. Apex 

 acute and hooked. 



Usual length a quarter of an inch, and breadth barely 

 a tenth of an inch. The largest specimens obtained at 

 Kadford Grove, were 3^ lines long, and 2 lines broad. 

 Animal dusky grey. 



Local, but widely dispersed, clinging to the stems and 

 leaves of aquatic plants (especially those of the water- 

 lily and Lotus), in ponds, lakes, and canals. 



Lays from five to twelve eggs, which hatch in from 

 24 to 26 days (Chautereaux). 



The Nottinghamshire localities are a ditch (rare), a 

 pond at Beeston Ryelands (rare), and in the sheet of 

 water at Radford Grove (exceedingly plentiful on the 

 Nuphar lutea and Nupharalba). 



More distant localities are Bristol (Miller), Wiltshire 

 (Montagu), Essex (Sheppard), Sussex (Paget), London 

 (Grey), Thames, Windsor (Brown), near Swansea (Jef- 

 freys), river Waveney,near Shotford Bridge, Norlhamp- 

 lonshire (Bloxam), river Eythrope, at Stone, Bucking- 

 hamshire (Reade), river Stour, Dorset, Windermere 

 lake, and pool near Eccles Station (Graham), Newcastle 

 (Alder), well distributed, but local, in Wales (Forbes), 

 local but having a wide range in Ireland (Forbes), and 

 only occurring in the south of Scotland, as in Dudding- 

 ston Loch, near Edinburgh (Forbes), Naas (Brown), 

 Belfast, Logan canal, and a pond at Moira, county of 

 Down (Thompson). 

 Specimens received from Darlington, from J. Graham, 



