mesotrochal

from The Collaborative International Dictionary of English v.0.48

Mesotrochal \Mes"o*tro`chal\, a. [Meso- + Gr. ? anything round,
   a hoop.] (Zool.)
   Having the middle of the body surrounded by bands of cilia;
   -- said of the larvae of certain marine annelids.
   [1913 Webster]