PELECYPODS 



463 



FAMILY PANDORID.E 

 GENUS Pandora 



JP. trilineata,. A little New England shell, remarkable on account 

 of its extreme flatness. When looking at this shell before opening it, 

 one naturally wondei-s where the animal 

 finds room to exist between two such 

 disk-like valves. The animal is very 

 thin, with largely united mantle-edges, 

 widely separated feeble adductor mus- 

 cles, and a fairly large tongue-shaped 

 foot. The shell is nacreous, rounded 

 anteriorly, and produced posteriorly 

 into a sort of upturned tip which gapes 

 to accommodate two little siphons. The dorsal hinge-margin is excavated 

 and curved. Length about one inch. It is abundant at Cape Cod, in 

 sandy stations, on oyster-beds, and is found from Maine to Florida. 



Pandui-a trilineata. 



