The Collaborative International Dictionary of English v.0.48:

Uncinata \Un`ci*na"ta\ ([u^]n"s[i^]*n[=a]"t[.a]), n. pl. [NL.,
   fr. L. uncinus a hook.] (Zool.)
   A division of marine chaetopod annelids which are furnished
   with uncini, as the serpulas and sabellas.
   [1913 Webster]