cephalotrocha

from The Collaborative International Dictionary of English v.0.48

Cephalotrocha \Ceph`a*lot"ro*cha\, n. [NL., fr. Gr. kefalh` head
   + ? wheel.] (Zool.)
   A kind of annelid larva with a circle of cilia around the
   head.
   [1913 Webster]