464 



a common pocket lens) in that part of the animal with- 

 in the fecond volution ; and which is of a reddifh chefnut. 

 When the animal is in motion (which is very flow) the 

 exterior whirl appears almofl empty. 



6S. • 



Nautileus, Turbo nautileus. Lin. Syfi. p. 1241. 



Gmcl6yji. p. 3612. 93. 

 Turt. Lin. iv, p. 501. 

 Chem. Conch, ix. t. 123. f. 1077. A. a. 

 Planorbis imbricatus. Mull, Verm.u. p. 165. No. 351. 



Schroet. Fliiffconch. p. 23S. No. 50. 

 Helix Walk. Min. Shells, f. 20. & 21. 



Helix cniiiiata, Turt. Lin. iv.'p. blO. 



Adams. Microfc. t. 14. f. 10 

 Helix fpinofa. Turt Lin. iv. p. 525. 



Adams Microfc. t. 14. f. II.— Id. t. 

 22. f. 39. 



H. with a pellucid, light horn-coloured fhell, much 

 (leprefied, with three or four volutions ; upper fide flat, 

 but the whirls well defined by the feparating line ; apex 

 not funk below the reft of the fliell : under fide largely 

 umbilicated. 



It is furniflied with diflant, elevated annulations, or 

 ribs, which feem to be partly teflaceous, and partly 

 membranaceous, for they are ftronger, and more perfett, 

 when the fliell is covered with a dark brown epidermis ; 

 in which flate a dorfal ridge or fub-carinated edge, of 



a mem- 



i 



