The Collaborative International Dictionary of English v.0.48:

Ostracion \Os*tra"ci*on\, prop. n. [NL., fr. Gr. 'ostra`kion
   small shell.] (Zool.)
   A genus of plectognath fishes of the family Ostraciontidae
   having the body covered with solid, immovable, bony plates.
   It includes the trunkfishes (also called boxfish).
   [1913 Webster +PJC]