To whom it may concern:
 
The definition of concha by the Spanish Larousse dictionary which is published
in Mexico and is universal no matter which country your in: "parte dura que
cubre el cuerpo de muchos molluscosy crustaceos (with an accent o, ver the a)
In english, a hard part that covers the body of many mollusks and crustaceans.
 
Emilio Jose