114 SHELLS. Class VI. 



Length about five inches ; breadth two and a 

 quarter. 



Inhabits frefh waters. 



Crows feed on thefe mufTels -, and alfo on dif- 

 ferent fhell-fifh. It is diverting to obferve, that 

 when the ihell is too hard for their bills, they 

 will fly with it to a great height, drop the Ihell 

 on a rock, and pick out the meat, when the 

 fhell is fra&ured by the fall. 



'Tab. Ixviii. fig. yg. 



PINNA. XVI. Its animal a Slug. 

 NACRE. 



Bivalve, fragil, furnifhed with a beard. 



Gapes at one end. Hinge without a tooth. 



Fragilis. P. with a very thin femi-pellucid whitifh Ihell, 

 So.Brittle moft p a k e near t0 t h e a p ex# Marked on the 



furface with longitudinal (lender ribs, roughened 

 with concave fcales -, and the whole traverfed 

 by innumerable finey?r/^. 



In young fhells the ribs and fcales are almoftob- 

 folete. The valves of leffer tranfverfe diameter. 



The largeft about five inches and a half long ; 

 and three and a quarter broad in the broadeft, part. 

 The figure is of a broader fpecimen than ufual. 



Dredged up at Weymcuth. From the Portland 

 cabinet. 



Tab. lix. fig. 80. 



3 I faw 



