54 MYAD^. 



The animal is much harger than the shell ; mantle closed through- 

 out except for the issue of the foot, and an opening for the siphons, 

 which are united to the end, and enveloped in a thick muscular 



Fis. 374. 



tissue continuous with the mantle ; foot rather small, conical ; bran- 

 chiae two-leaved each side. 



Its proper halntat is the Banks of Newfoundland ; lint several 

 fine specimens have been hooked up or dredged in the neighbor- 

 hood of Provincetown, within the Cape. Nahant Beach, after 

 storms {Haskell) ; Halifax, Sable Island ( Willis) ; Rimouski, Mar- 

 couin {Bell). 



It is a very interesting shell, the only living one of the genus 

 yet known. Its wide gaping, thick interior deposit, toothless hinge, 

 and black exterior, render it impossible to confound it with any 

 other shell. The great size of the animal, which the shell can 

 never enclose, renders it a welcome morsel for that denizen of the 

 Banks, the cod-fish ; and, accordingly, it is not difficult to olttain 

 specimens through the fishermen. In young shells the epidermis 

 is smooth, and of a light chestnut-color. 



Family MYAD^. 



Shell often inequivalve, inequipartitc, gaping ; hinge with a 

 more or less spoon-shaped tooth in one valve, received into a cor- 

 responding excavation in the opposite valve, united by an interposed 

 cartilage. 



Ocnus MVA, Lin. 1747. 



Shell transverse, gaping at both ends ; left valve with a single 

 broad, compressed, erect tooth, received into a pit in the o])positc 

 valve. 



