The Duck-bill Shells and Lantern Shells 



is concave, the other margins rounded. At the extreme posterior 

 end the valves are spread apart to let the short, forked siphon 

 tube through. The foot is finger-like. The muscles are weak, 

 the body thin and inactive. The three lines are parallel with 

 the margin, extending all the way around from the beak. 



About Cape Cod this mollusk is plentiful. It frequents oyster 

 beds and sandy or muddy bottoms, burrowing at varying depths. 

 Length, i inch. 



Habitat. — Maine to Florida. 



331 



