The Collaborative International Dictionary of English v.0.48:

Urochorda \U`ro*chor"da\, Urochordata \U`ro*chor`da"ta\, prop.
   n. pl. [NL. See Urochord.] (Zool.)
   Same as Tunicata.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Urochordata
    n 1: tunicates [syn: Urochordata, subphylum Urochordata,
         Urochorda, subphylum Urochorda, Tunicata, subphylum
         Tunicata]