459 



65. 

 Helix uinbillcata quatuor anfractibus apertura fubrotunda. Alba. 



IValL Min. Shells, f. 19. 

 Helix alba. Gincl Syft p.3625.— ^ar^ Lin. iv. p.511. 



Petiv. Gaz. t. 92. f. 7. 

 Planorbis albus. Midler Venn. iii. p. 164. No. 350. 



Schroeter FhJJconch. p. 225. t. 5. f. 12. 



11. with a fub-pellucid, light horn-coloured {hell, co- 

 vered when alive, with a brown epidermis, that renders 

 it opaque : volutions four, placed lateral, comprefTed : 

 the outer one rather inclining to an edge, but is not ca- 

 rinated: on the upper part, the apex is deprelTed into a 

 fub -umbilicus : the bafe more flrongly umbilicated : the 

 whole fliell, when examined by a common magnifying 

 glafs, is obferved to poffefs very fine ftri^, both tranf- 

 verfe and longitudinal, in a flightly decuffated manner: 

 aperture fub-orbicular, fub-lunated, clafping the body 

 v^^hirl ; margin thin, oblique. 



This fpecies, wliich is defcribed and figured by Wal- 

 ker, we originally received from Mr. Boys of Sand- 

 wich for fuch: and have fince found it of a much fupe- 

 rior fize, rather exceeding a quarter of an inch in dia- 

 meter ; which is more than double that which Mr. 

 Walker took his figure from. 



It is one of the moft common of the comprelTed fpecies 

 o^ Helix; is plentiful in tbe river Avon about Lackhain 

 in Wiltpdre, as well as in the fifli-ponds; and in many 

 other places in the fame county, efpecially at Wcdham-p- 

 ton, in ditches and ponds, of a fuperior lize. 



N n n 2 We 



