PLATE X. 



Dr. Rutty mentions a Pinna ten inches long and five broad, caught 

 near the Skerries, in Ireland ; and Mr. Pennant " saw specimens of 

 vast Pinna, found among the farther Hebrides, in the collection of 

 Dr. Walker^ at Moffat " but it is uncertain of what species either 

 of these were : Mr. Pennant says, " they were very rugged on the 

 outside, but cannot recollect whether they were of the kind found in 

 the Mediterranean or West Indies*." 



The only British species of Pinna we are acquainted with, Is the 

 P. Muricata of Linnaeus, or P. Fragilis of Pennant, and that is veiy 

 rare. The latter author describes it from a specimen in the Portland 

 cabinet, which had been fished up at Weymouth, in Dorsetshire. Da 

 Costa says, he has seen a very small one (of the same species) from the 

 coast of Wales. — Both of these are represented in the annexed plate. 



This Shell Is extremely thin and brittle, and gapes open at the 

 broadest end. It is semi-pellucid, and of a horn colour ; the outside 

 marked with longitudinal ribs, roughened with rows of small prickles f. 

 The inside Is smooth, of a pale horn colour alfo, with a pearly lustre 

 towards the top. 



* This Author, however, arranges U as a new Briti$h species, without farther d«* 

 scription: — as, Pinna Ingens — Great Nacie. 



•\ In Pennant's figure these are obsolete. 



