Tunicata

2 definitions found

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

  Tunicata \Tu`ni*ca"ta\, pr. n. pl. [NL. See {Tunicate}.] (Zool.)
     A grand division of the animal kingdom, intermediate, in some
     respects, between the invertebrates and vertebrates, and in
     modern classifications considered a subphylum of the
     vertebrates; called also urochordata. 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.
     [1913 Webster]
  
     Note: Most of the species when mature are firmly attached to
           foreign substances, but have free-swimming larvae 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}.
           [1913 Webster] Tunicate

From WordNet (r) 2.0 [wn]:

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