eudipleura

from The Collaborative International Dictionary of English v.0.48

Eudipleura \Eu`di*pleu"ra\, n. pl. [NL., fr. Gr. e'y^ well + ?
   double + ? rib,?, pl.,side.] (Biol.)
   The fundamental forms of organic life, that are composed of
   two equal and symmetrical halves. --Syd. Soc. Lex.
   [1913 Webster]