undulating membrane

[ ŭnjə-lā′tĭng, -də- ]

n.

An organelle of locomotion in certain flagellate parasites consisting of a finlike extension of the cytoplasmic membrane with the flagellar sheath.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.