PLATE LXXXV. 



This species is similar in its external appearance to the Mactra Lu- 

 traria; yet it may be immediately distinguished from that shell by the 

 singular structure of the hinge. The large, erect, plate-like tooth 

 common to the Mya genus, is particularly characteristic in this 

 species. 



Da Costa received it from the Isle of Wight, near Newport, 

 and from Bigbury-Bay, near Faversham ; but observes, it is not a com- 

 mon shell. 



