Ostracion

from the GNU version of the Collaborative International Dictionary of English

• proper n. 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).

from The Century Dictionary and Cyclopedia

• n. A genus of fishes with an exoskeleton of juxtaposed hexagonal plates forming a hard shell of bone, typical of the family Ostraciontidæ They are known as cow-fishes, trunk-fishes, and coffer-fishes. See cut under cow-fish.
• n. [lowercase] A fish of this genus; an ostraciont.