Defn: One of an extinct genus of fossil cephalopods, allied to the Ammonites. The earliest forms are found in the Devonian formation, the latest, in the Triassic.

GONIDIAL
Go*nid"i*al, a. (Bot.)

Defn: Pertaining to, or containing, gonidia.

GONIDIAL
Go*nid"i*al, a. (Zoöl.)

Defn: Of or pertaining to the angles of the mouth; as, a gonidial groove of an actinian.

GONIDIUM
Go*nid"i*um, n. Etym: [NL., fr. Gr. (Zool.)

Defn: A special groove or furrow at one or both angles of the mouth of many Anthozoa.

GONIDIUM
Go*nid"i*um, n.; pl. Gonidia. Etym: [NL., fr. Gr. (Bot.)

Defn: A component cell of the yellowish green layer in certain lichens.

GONIMIA
Go*nim"i*a, n. pl. Etym: [NL., fr. Gr. (Bot.)