211 



We fliall however take the liberty of remarking, that 

 this fyftem will not hold good with refpeft toConchologv, 

 where the fhells, and not the animals, have been claded : 

 could we examine the animal inhabitant of every fpecies 

 of fhell, we fliould find that, on the prefent arrangement, 

 fome in each genus would differ from the generic chara61er. 

 But as we never can poffibly have an opportunity of ex- 

 amining more than a very fmall portion of fliells with 

 their living animals, fuch new fyflematifls mufl again be 

 reduced to clafhfication by the fliell, and not by the ani- 

 mal. That an attention to the animal inhabitants of (hells 

 is ofeffential fervice in the difcrimination of fpecies, can- 

 not be denied, but mufl be wholly confined to fpecific, 

 not generic diftinftions. 



5; 

 B. with afub-oval, extremely thin, pellucid, white fliell, Haliotoidea. 

 with fomewhat the habit of a Haliotis, but deftitute of the Tab. 7. f. C, 

 fmall perforations that mark that genus : it is fmooth and 

 glolfy, but not quite deftitute of wrinkles : aperture oval, 

 not quite extending to the apex, which is fmall, obtufe, 

 and convoluted fideways, fcarce making two volutions: 

 the body of the fhell is very fmall, and only turns a little 

 inv/ards, fpirally : interior part vifible to the end. Length 

 three-quarters of an inch; breadth half an inch. 



This fpecies differs from the B. aperta in the aperture 

 not extending to the upper end, and in having a con-, 

 torted apex. 



Ee 2 W^ 



