BITHINIA. 27 



Bithynia Leachii. Leach, Syn. Moll. 209 ; Forbes and 

 Hanley, B. M. Hi. 16. t. 71. f. 78. t. H.H. f. l. Paludina 

 Trochelliana. Philippe. Paludina Kickxii. Vestend, Bull. 

 Acad. Briuc. 1835, 375. Paludina decipiens. Mich. Mag. 

 Zool 1843, 2. t. 64. f. 2. Paludina Michaudi. Duv. in 

 Rev. Geol. 1845, 211. Bithinia Kickxii and B. Michaudi. 

 Dnpuy, Moll. Paludina acuta, Fleming. Br. Anim. 315. 

 Cyclostoma simile. Drap. 31. t. 4. f. 15. (?) Paludina 

 ventricosa. " Leach, MSS.;" Sheppard, Brown, Brit. 

 Shells, t. 41. f. 74, 75. Paludina humilia. N. Boubee, Cat. 

 Paludina similis. Turton, Man. 135. f. 121. Alder, Mag. 

 Zool and Bot. ii. 116. 



In ditches and canals ; often even where the 

 water is slightly brackish ; south of England. ( Gray, 

 1821.) 



Shell a quarter of an inch long, and two lines 

 broad, with four or five very tumid volutions ; aper- 

 ture dilated, nearly circular, projecting more out- 

 wardly, or out of the line of the columnar axis, with 

 a small umbilicus behind it. 



The fry, or mass of egg, of this species, are dis- 

 posed on a tough strap-shaped green membrane, in a 

 double row, consisting of six or seven pairs placed 

 opposite to each other ; and this elongated receptacle 

 is fixed to the under surface of aquatic plants. 



Mr. Sheppard received it from Dr. Leach, under 

 my name, but he changed it to Turbo Leacliii. I 

 do not think it is C. simile of Draparnaud : in Dr. 

 Turton's figure the volutions are scarcely sufficiently 

 ventricose. 



The shell is often covered with a ferruginous in- 

 crustation, and the apex of the spire is sometimes 

 eroded. 



Mr. Alder observes (Mag. Zool. and Bot. ii. 116.), 

 " The Paludina viridis of Turton's Manual (ed. 1. 



