mesectoderm

[mĕz-ĕktə-dûrm′]
n.
  1. The part of the mesenchyme derived from ectoderm, especially from the embryonic neural crest from which the pigment cells, meninges, and most of the branchial cartilages develop.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.