Source : Webster's Revised Unabridged Dictionary (1913)

Appendicularia \Ap`pen*dic`u*la"ri*a\, n. [NL.] (Zo["o]l.)
   A genus of small free-swimming Tunicata, shaped somewhat like
   a tadpole, and remarkable for resemblances to the larv[ae] of
   other Tunicata. It is the type of the order Copelata or
   Larvalia. See Illustration in Appendix.

Source : WordNet®

appendicularia
     n : free-swimming tadpole-shaped pelagic tunicate resembling
         larvae of other tunicates