nemertine

from WordNet (r) 3.0 (2006)

nemertine
    n 1: soft unsegmented marine worms that have a threadlike
         proboscis and the ability to stretch and contract [syn:
         {ribbon worm}, {nemertean}, {nemertine}, {proboscis worm}]

from The Collaborative International Dictionary of English v.0.48

nemertine \nemertine\ n.
   Any of an order ({Nemertina}) of soft unsegmented marine
   worms having an eversible threadlike proboscis and the
   ability to stretch and contract.

   Syn: ribbon worm, nemertean, proboscis worm.
        [WordNet 1.5]