1.^ 



OlO 



T. with a pellucid, glolTy, white (hell, with fix volu- 

 tions, fomewhat rounded, and feparated bv a well defi- 

 ned line : the upper part of each volution faintly ribbed ; 

 the whole fliell very finely and regularly Briated tranf- 

 verfely: apex moderately pointed: aperture fub-oval, 

 marginated. Length one eighth of an inch; breadth ra- 

 ther more than one third of its length. 



Live fliells are covered with a brown epidermis, that 

 obfcures their beauty; in this (late we found it plentiful 

 at Plymouth at the roots of algce. It is alio common on 

 other parrs of the coaft of Devon ; and fparingly at Fal- 

 mniith, and other pans of Cornwall. Mr. Walker fays 

 Shepey iflnnd, very rare: and Mr. Adams found it on 

 the coaft oS. Fembrokejhire. 



21. 

 T. with a ftrong. conic, gloffy, white fhell, with feven Bryereus. 

 fmooth fpires finely coftated: the volutions are fomewhat Tab. 15. f. S, 

 rounded, and well defined by the line of feparation ; but 

 fcarcely interrupt the ribs, (which are feventeen or eigh- 

 teen in number,) from continuing throughout the 'l-iell : 

 aperture oval; outer lip ftrong; pillar lip replicate, 

 fmooth. 



A variety with ftronger, and fewer ribs, not exceeding 

 ten or twelve in number. 



At firft fight this has fomewhat the appearance of T, 



S f cojlatui 



