THE 



NATURAL HISTORY 



OF 



BRITISH SHELLS. 



— •»»»4£& 099 «- 



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 opposite valve. 



SPECIFIC CHARACTER 



AND 



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 



