Source : Webster's Revised Unabridged Dictionary (1913)

Tunicata \Tu`ni*ca"ta\, n. pl. [NL. See {Tunicate}.] (Zo["o]l.)
   A grand division of the animal kingdom, intermediate, in some
   respects, between the invertebrates and vertebrates, and by
   some writers united with the latter. They were formerly
   classed with acephalous mollusks. The body is usually covered
   with a firm external tunic, consisting in part of cellulose,
   and having two openings, one for the entrance and one for the
   exit of water. The pharynx is usually dilated in the form of
   a sac, pierced by several series of ciliated slits, and
   serves as a gill.

   Note: Most of the species when mature are firmly attached to
         foreign substances, but have free-swimming larv[ae]
         which are furnished with an elongated tail and somewhat
         resemble a tadpole. In this state the larva has a
         urochord and certain other structures resembling some
         embryonic vertebrates. See {Ascidian}, {Doliolum},
         {Salpa}, {Urochord}, and Illust. of {Social ascidian},
         under {Social}.

Source : WordNet®

Tunicata
     n : tunicates [syn: {Urochordata}, {subphylum Urochordata}, {Urochorda},
          {subphylum Urochorda}, {subphylum Tunicata}]