Clypeus-anterior: see ante-clypeus.
Clypeus posterior: see post-clypeus.
Coactus: condensed; of a short stout form.
Coadapted: formed so as to work together to one end; as the mandible and maxilla in Chrysopids, etc.
Coadunate: joined together at base; two or more joined together; said of elytra when permanently united at the suture.
Coagulate: to congeal; to change from a fluid to a jelly.
Coagulum: a clotted mass, as of blood.
Coalescent: united or grown together.
Coarctate: contracted: compacted: applied to that form of pupa in which all the members of the future adult are concealed by a thickened, usually cylindric case or covering, which is often the hardened skin of the larva: beginning with a narrow base, then dilated and thickened.
Cocardes: retractile vesicular bodies on each side of the thorax in certain Malachidae.