Coccineous: cochineal red; dark red [carmine].
Cochleiformis: formed like a snail shell.
Cochleate: spirally twisted like a screw or a univalve shell.
Cocoon: a covering, composed partly or wholly of silk or other viscid fibre, spun or constructed by many larvae as a protection to the pupa.
Cocoon-breaker: structures or processes of the pupa, often on the head, by means of which it works its way out of the cocoon.
Coecal: ending blindly, or in a closed tube or pouch.
Coecum: a blind sac or tube: applied to a series of appendages opening into the alimentary canal at the junction of the gizzard and chylific ventricle: see caecum; the two are used interchangeably.
Coeloblast: the endoderm in the narrower sense.
Coelom: the body cavity.
Coelomic cavity: the space between the viscera and the body wall.