91 



in all the gradations, even that which conne6ls them with 

 Bulla diaphana \ fo that we have no hefitation in bringing 

 thefe four fpecies into one. It is true fome of our concho- 

 logical friends did exprefs fome doubts about Bulla diapliana, 

 fufpe6ling it was the infant Cyprcea, and we might have ac- 

 ceeded, did not the animal alfo in that flate differ as much 

 from the adult as its fhell, and thus deceived us. In this infant 

 ftate the animal does not cover the (hell with the reflexed 

 membrane, as in adults, nor is the animal in the next ftage 

 perfeflly formed and coloured in that part. 



Having acknowledged the error in making Bulla diaphana 

 a diftin6l fpecies we beg that fhell may be erafed. 



The Cyprcea Europcea with fpots, and that without fpots, 

 termed arctica, may be confidered as perfecSlly formed va- 

 rieties ; the fmooth kind, originally intitled bullata, is the 

 fame fpecies in the adolefcent ftate ; and Bulla diaphana the 

 firll and moft imperfe6lly formed fhell. 



Voluta l^evis, Don. Br. Shells, v.t. 165. Voluta 



Lin. Trans. \'n\.i^. i33. p. 203. 



Mr. Donovan informs us, the figures of this fpecies given 

 by him were engraved from fpeciniens originally in the 

 Portland cabinet, and that they were taken in deep water at 

 JVeymouth. 



M 2 BULLA. 



