In the Decapoda, the cephalon is formed by the first six somites of the body, and is fused with the eight thoracic somites to the cephalothorax. The first cephalic somite (= the ophthalmic somite) carries the eyes, the second (= antennular somite), the antennulae, the third (= antennal somite), the antennae, the fourth, the mandibles, the fifth, the maxillulae, and the sixth, the maxillae.

Alternative form for cephalon : head.