1) Genus ensis 2) Mollusk genus 3) Razor clam 4) Razor clams 
Ensis is a genus of medium-sized edible saltwater clams, littoral bivalve mollusks in the family Pharidae. They are known in Scotland as Spoots, for the spouts of water they eject while burrowing into the sand, when visible at low tide. This term may also colloquially include members of the genus Solen. The shells are long, narrow, and parallel-si...
(from the article `bivalve`) ...right valves. In deeper-burrowing species the shells are laterally compressed, permitting more rapid movement through the sediments. The shells of ...
[n] - razor clams
genus Ensis noun razor clams