THE 



NATURAL HISTORY 



OF 



BRITISH SHELLS. 



PLATE LXXIII. 



MYA MARGARITIFERA. 



RIVER PEARL MUSCLE. 

 GENERIC CHARACTER, 



Animal an Ascidia. Shell bivalve, gaping at one end. The hinge 

 for the most part furnished with a thick strong broad tooth, not 

 inserted into the oppofite valve. 



SPECIFIC CHARACTER 



AND 



r'Ui -• SYNONYMS. 



Shell oblong, thick, and covered with a coarse black epidermis, 

 much decorticated or worn down about the beaks. A large notched 

 conic tooth in one valve, and two small ones in the other, 



A 2 



