451 



concave, and the whole fliell finely ftriated or wrinkled 

 acrofs the whirls : round the margin of the bafe is a fine 

 carinated ridge: aperture oval, fomewhat angulated, 

 not even, but flanting towards the bafe. Diameter about 

 five-eighths of an inch. 



This fpecies, which has been generally miftaken for 

 the H. Planorbis of Linn ^ us, is common in mofl flat 

 countries abounding with wet ditches and water-courfes: 

 is frequent alfo in rivers, and ponds. 



Animal dufl^y, with two long, flender, fetaceous tentacu- 

 la, of the fame colour, opaque, and very dark in the mid- 

 dle, but fomewhat tranfparent along the fides : eyes placed 

 on the head, at the bafe of the tentacula beneath. 



""^^ 61. 



Helix Planorbis. Lin. Syft. ^.\2A2. — Gmd. 5)/. p.3617. Carinata. 



Tart. Lin. iv. p. 505. 

 Planorbis carinatus. jl/?///^r Verm, ii.-p. 157. No. 344. 



Chem. Conch, ix. t. 126. f. 1 102. a. b. 

 Schroeter Fliiffconch. p.225. t. 5. f. 13. 

 14. 15. 



H. with a depreffed, flat, fub-pellucid fliell, of a light 

 horn-colour, fomewhat gloffy ; volutions four, laterally 

 placed upon each other; the outer one broad, not much 

 rounded, but floping gradually to a fliarp carinated 

 ridge, that furrounds the fliell: the interior volutions 

 are fmall, and fuddenly decreafe to the centre, where it 

 finks into a fmall umbilicus : the bafe is nearlv flat, the 

 inner volution not being funk, but is on a level with the 



M m m 2 others : 



