i 



NORTH BRITISH TESTACEA. 



375 



Mta. 



4. truncita. 



P. D. IVL 



Dunbar, Aberlady Bay, and 

 other parts of the Frith, 



common. 



5. decusiata. 



M. 



New species, found near 

 Dunbar. 



6. nitens*. 



M. 



New species, Dunbar, very 

 rare. Only one specimen 

 has occurred. 



7. ferruginosa. 



M. 



New species from Porto Bel 



lo Sands and near Dunbar., 

 rare. 



S. suborbicularis. M. Dunbar, seldom found per 



This is a new genus, formed by my friend G„ 

 Montagu, Esq; author of Testacea Britannica. In 

 this genus are brought together several shells 

 which by other authors were placed in the two 

 genera Mya and Mactra. 



I think it necessary here to notice, to prevent 

 confusion, that the name Ligida has been already 

 given to a genus of shells very different from these \ 

 of which I am of opinion my friend Mr Mon- 

 tagu was not aware, though I am certain it was 

 the intention of Dr Solander, if he had lived, |o 

 have formed this genus. In Monsieur Calbnne's 

 Catalogue of Shells, the genus Ligiila is formed 

 from several univalve shells, taken from the genera 



£e&. 



LIGULA. 



Aa 4 



* Tab. viii. fig. 4. Natural size, 



