OSTRACODERMI
Os`tra*coder"mi, n. pl. Etym: [NL., fr. Gr. (Zoöl.)

Defn: A suborder of fishes of which Ostracion is the type.

OSTRACOID
Os"tra*coid, a. (Zoöl.)

Defn: Of or pertaining to the Ostracoidea.
— n.

Defn: One of the Ostracoidea.

OSTRACOIDEA
Os`tra*coi"de*a, n. pl. Etym: [NL., fr. Gr. -oid.] (Zoöl.)

Defn: An order of Entomostraca possessing hard bivalve shells. They are of small size, and swim freely about. [Written also Ostracoda.]

OSTREA
Os"tre*a, n. Etym: [L., an oyster.] (Zoöl.)

Defn: A genus of bivalve Mollusca which includes the true oysters.

OSTREACEOUS
Os`tre*a"ceous, a. Etym: [L. ostrea an oyster. See Oyster.] (Zoöl.)