ACEPHALOUS, headless, whether literally or metaphori cally, leaderless. The word is used literally in biology, and metaphorically in prosody or grammar for a verse or sentence with a beginning wanting. In zoology, the Mollusca are divided into cephalous and acephalous (Acephala), according as they have or have not a head. The Acephala, or Lamellibranchia (q.v.), are the bivalve shell-fish. In botany the word is used for ovaries not terminating in a stigma.