41 



after the eggs have been deposited, and two year 

 elapse before they become fully grown. 



It seems to thrive in couiinement. 



The usual length is half an inch, and the breadth 

 four lines, as measured in the broadest part. Speci- 

 mens procured from the Musco-sic dyke, near Beeston, 

 measure seven-twelfths of an inch in length, and four- 

 twelfths of an inch in breadth on the lowest whorl. 



An inhabitant of ditches, brooks, canals, and rivers j 

 mostly found clinging to aquatic plants, and seeming 

 to prefer those places most overrun with aquatic vege- 

 tation, and consequently being more or less stagnant. 



The localities in the neighbourhood of Nottingham 

 are very numerous, the principal ones are, an almost 

 stagnant ditch close to the canal near the Priory at 

 Lenton (where it occurs in such vast numbers that it is 

 surprising they have room to live and move about, for 

 stones in the water may be found covered six, eight, or 

 ten deep) ; a clear dyke at Beeston ; the Trent at Bees- 

 ton, Attenborougb, and Sawley (amongst algas on the 

 water's edge) ; clear dykes at ChilweJl and Atten 

 borough; the Musco-sic dyke near Beeston (where it 

 grows to a large size, and is more than ordinarily pro- 

 duced in its form) ; the river Leen at Bulwell ; a small 

 stream at Radford Grove; and in dykes in the Notting- 

 ham Meadows. 



It is a common shell throughout England, but be- 

 coming less abundant in the more northerly counties, 

 The following are a few (of the hundreds) of the more 

 distant localities:— Near London (Grey), Kent and 

 Dorsetshire (Montagu), Bristol and Wiltshire (Miller), 

 Essex (Sheppard), Suffolk (Paget), Norfolk (Bloxham), 

 Newcastle (Alder), Darlington near Durham (Graham), 

 Kendal (Gough). 

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