Pilidium

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pilidium \Pi*lid"i*um\, n.; pl. {Pildia}. [NL., fr. Gr. ?, dim.
     of ? a cap.] (Zool.)
     The free-swimming, hat-shaped larva of certain nemertean
     worms. It has no resemblance to its parent, and the young
     worm develops in its interior.
     [1913 Webster]