94 PHYTOPHAGA. 



6. 2. BITHINIA ventricosa. Ventricose Bithinia. (t. 

 8. f. 121.) Shell conic, yellowish horn-colour, 

 smooth, semi-transparent, with five very tumid 

 volutions, and a small oblique umbilicus. 



Bithinia ventricosa. Gray, M. Rep. 1821, p. 239. 



Turbo Leachii. Sheppard, Linn. Trans, xiv. 152. 



Paludina acuta. Fleming. 



Cyclostoma simile. Drap. 31. t.4. f. 15.? 



Paludina ventricosa. " Leach, MSS. ; " Sheppard, 

 Brown, Brit. Shells, t.41.f.74, 75. 



Paludina humilis. N. Boubee, Cat. 



similis. Turton, Man. 135. f. 121.; Al- 

 der, Mag. Zool. and Bot. ii. 116. 



In ditches and canals ; south of England. 



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 lower volutions are sometimes decussated, the 

 horizontal striae being the deepest. See Linn. Trans. 

 xiv. 152. 



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. 



This species was first added to the list, in the 

 Medical Repository for 1821. Mr. Sheppard received 

 it from Dr. Leach, under my name, but he changed 

 it to T. Leachii. I do not think it is C. simile of 

 Draparnaud : in Dr. Turton's figure, the volutions are 

 scarcely sufficiently ventricose. 



