Coelenterata

(Gr. koilos, hollow; enteron, the bowel). The sub-kingdom which comprises the Hydrozoa and Actinozoa. Proposed by Frey and Leuckart in place of the old term Radiaia, which included other animals as well.

Coenenchyma

(Gr. koinos, common; enchuma, tissue ; literally, an infusion). The common calcareous tissue which unites together the various corallites of a compound corallum.

COENOECIUM

(Gr. koinos, common; oikos, house). The entire dermal system of any Polyzoon; employed in place of the terms polyzoary or polypidom.

COENOSARC

(Gr. koinos, common; sarx, flesh). The common organised medium by which the separate polypites of a compound Hydrozoon are connected together.

Coleoptera

(Gr. koleos, a sheath; pteron, wing). The order of Insects (Beetles) in which the anterior pair of wings are hardened, and serve as protective cases for the posterior pair of membranous wings.

Collembola

(Gr. kolla, glue; embolos, a sharp beak or pointed projection). An order of Apterous insects furnished with an adhesive ventral process.

Colubrina

(Lat. coluber, a snake). A division of the Ophidia.

Columbacei

(Lat. columba, a dove). The division of Rasorial Birds comprising the Doves and Pigeons.

Columella

(Lat. dim. of columna, a column). In Conchology, the central axis round which the whorls of a spiral univalve are wound. Amongst the Actinozoa, it is the central axis or pillar which is found in the centre of the visceral chamber of many corals.

Column

Applied to the cylindrical body of a Sea-anemone (Actinia); also to the jointed stem or peduncle of the stalked Crinoids.

Commensal

(Lat. cum, with ; mensa, table). Living at the same table with, a messmate : Applied to animals which live on or in other animals for part or the whole of their life, simply sharing the food of their host, without . being parasitic on him.

Commissural

(Lat. committo, I solder together). Connecting together: usually applied to the nerve-fibres which unite different ganglia.

Concha

(Lat. a shell). The external ear by which sounds are collected and transmitted to the internal ear.

Conchifera

(Lat. concha, a shell; fero, I carry). Shell-fish. Applied in a restricted sense to the bivalve Molluscs, and used as a synonym for Lamelli-branchiata.

Condyle

(Gr. kondulos, a knuckle). The surface by which one bone articulates with another. Applied especially to the articular surface or surfaces by which the skull articulates with the vertebral column.

Conirostres

(Lat. conus, a cone; rostrum, a beak). The division of Perching Birds with conical beaks.

Copepoda

(Gr. kope, an oar ; podes, feet). An order of Crustacea.

Coracoid

(Gr. korax, a crow; eidos, form). A separate bone which enters into the composition of the pectoral arch in Birds, Reptiles, and Mono-tremes. In most Mammals it is a mere process of the scapula, having, in man, some resemblance in shape to the beak of a crow.