107 



Planorbis carinatus. Drap.p. 46. t. 2.f. 13, 14, 16. 



. Brard, p. 150. t. 6./. 3. 



Helix planata. Linn. Trans, viii. ^9. 189. t. 5.f. 14. 

 Helix Planorbis. 2\irt. Diet. _^j. 45. 



Shell hardly half an inch in diameter, with five vo- 

 lutions, the outer one growing suddenly larger, a 

 little depressed on the upper side, and nearly flat 

 on the under : colour pale horn-colour and trans- 

 parent, often covered with a brownish coat : aper- 

 ture contracted to a point above in consequence of 

 the keel. 



In stagnant waters. 



88. Vla-sorbis mar ginatus. Shell horn-colour, brown, 

 semitransparent, striolate, a little concave above, 

 and flatter beneath, with a prominent obtuse keel 

 placed near the base. 



b. with the keel very obscure. 



Planorbis marginatus. Drap.p.45. t. 2.f. 11,12, 15. 



■ Brard, p. 152. t. 6./. 5. 



Helix Planorbis. Linn. Syst. i. 1242. 

 Helix complanata. Mont.p). 450. t. 25. f. 4. 



Shell resembling the last, but is more concave above, 

 and flatter underneath in consequence of the keel 



