The Collaborative International Dictionary of English v.0.48:

Turbellaria \Tur`bel*la"ri*a\, n. pl. [NL., dim. fr. L. turbo a
   whirling.] (Zool.)
   An extensive group of worms which have the body covered
   externally with vibrating cilia. It includes the
   Rhabdoc[oe]la and Dendroc[oe]la. Formerly, the nemerteans
   were also included in this group.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Turbellaria
    n 1: free-living flatworms [syn: Turbellaria, class
         Turbellaria]