English edit

 
a boat shell Crepidula porcellana
 
a boat shell Cymbium tritonis

Noun edit

boat shell (plural boat shells)

  1. (zoology) A marine gastropod of the genus Crepidula. The species are numerous.
  2. (zoology) A marine univalve shell of the genus Cymbium, syn. Cymba.

Further reading edit

Crepidula
Cymbium

Anagrams edit