razor shell 
noun
A burrowing bivalve mollusc with a long slender shell which resembles the handle of a cut-throat razor. Also called jackknife clam or razor clam in North America.
- Family Solenidae: Ensis and other genera.
- The middle regions of the beach are surf-beaten, but the sheltered southern corner, at low tide, reveals fine sands thickly populated with razor shells, tellins, surf clams and sand mason worms.
- Other prey, such as bristle worms, razor shells and tellins are also taken when available.
- machicoulis
- polychromous
- polychromy
- polychronic
- polycistronic
- polyclad
- polyclimax
- polyclinic
- Polyclitus
- polyclonal
- polyclonal antibody
- polyclonality
- polyclonally
- polyclone
- polycondensate
- polycondensation
- polycondense
- polycondensed
- polyconic
- polycormic
- polycotton
- polycotyledon
- polycotyledonary
- polycotyledonous
- polycotyledony