PLATE CXLIIL 



Conchology, under the name of Bulla, the Bubble (Aperta, Linn.) 

 and refers to the figure in the work of Pennant accordingly ; but 

 in this instance he was much mistaken, for the two shells are per- 

 fectly distinct ; and it appears certain, that the shell described by Da 

 Costa was as much unknown to Pennant, as that of Pennant was to 

 Da Costa. The shell of the latter is figured in Plate 120 of this 

 work, and the true Bulla patula of the other is figured in the Plate 

 annexed. 



This we apprehend to be one of the rarest of the British shells 

 hitherto discovered ; Pennant notes it from Weymouth, and refers 

 for his specimen to the Portland Cabinet : our shell is from Wey- 

 mouth likewise. 



