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. Coelom-sac: the cavity containing the viscera: in embryology one of a pair of closed sacs, arising in the mesoderm of each segment of the embryo and giving rise to more or less of the coelom of the adult. Coenogonous: oviparous at one season of the year, ovoviviparous at another, as in Aphididae. Coeruleus -eous: sky-blue: see caeruleus. Coincident: when two wing veins run together or lie, one in continuation of the other so as to appear like one. Coleoptera: sheath-winged: an order with the primaries coriaceous, used as a cover only, meeting in a straight line dorsally; mouth mandibulate; pro-thorax free; transformation complete: the beetles: the term has also been applied to the two elytra together. Collar: in general any structure between the head and thorax: specifically, in Hymenoptera, the neck; in Diptera, may mean the neck, the sclerites attached to the thorax, the thorax itself, or its processes (ante furca): in Coleoptera, is the narrowed thorax; in Lepidoptera, applied to the sclerites attached to the thorax and which shield the neck. Collembola: an ordinal term applied to species which are apterous; have no metamorphoses; have variably developed abdominal saltatorial appendages and a peculiar ventral tube at base: the spring-tails. Colleterial gland: see Colleterium. Colleterium: a glandular structure accessory to the oviduct, secreting the viscid material used in cementing the eggs together. Collophore: the sucker-like organ extended from the underside of the abdomen in Collembola. Collum: the neck or collar: the slender connection between head and thorax in Hymenoptera and Diptera; in Coleoptera, the posterior, narrow part of the head or even the thorax: loosely used. Colon: the large intestine; that usually enlarged portion of the alimentary canal before the rectum. Columella: a little rod, pillar or central axis. Columnar: cylindric, but tapering toward one end. Comate -us: only the upper part of head, or vertex, covered with hair. Commensal: one who eats at another's table: applied to species that feed on the surplus supply of another, without destroying the owner of the supply. Commensalism: applied to this manner of living and eating together.