104 ON THE PINNA INGENS. 



Mr Stewart, in his " Elements of Natural Kis- 

 " tory," mentions, in course, this shell, and says, 

 in vol. ii. page 381. that " a very large species 

 " was found by Dr Walker, off the island of 

 " Barra, in 1764, called by him Pinna borealis" 



In the " Testacea Britannica," of that labori- 

 ous and able conchologist, George Montagu, Esq ; 

 page 180., he describes a shell under the name 

 Pinna ingens, discovered by him in Salcombe 

 Bay on the south coast of Devonshire ; and he 

 adds a full and circumstantial description of 

 the same, but unfortunately is led into an error by 

 observing a few concave spines on his specimen ; 

 for which reason he quotes a synonyme from Lister, 

 but with a note of interrogation expressing his 

 doubt. On referring to this synonyme, and the 

 plate given by Lister, we find the shell to be the 

 Pinna muricata. The similarity of shape also 

 tended to mislead this author. Where no perfect 

 description has been given, or any figure or 

 true synonyme to follow it up, vague conjec- 

 ture must necessarily be the result. This ac- 

 curate conchologist seems, however, to be the 

 only one who has formed any just idea of the 

 shell of Pennant, as, in his account, page 181., 

 he gives the description from Pennant, and 

 adds, " Mr Pennant seems to be the only 

 " one who has made mention of this shell, and 

 " that under the denomination of Pinna ingens." 

 In his Appendix, page 583, he appears to be 

 farther confirmed in this opinion, and says, " This 



