embryonic membrane

English Thesaurus

1. the inner membrane of embryos in higher vertebrates (especially when covering the head at birth) (noun.body)

hypernym	:	fetal membrane,
definition	:	any membrane that functions for the protection or nourishment or respiration or excretion of a developing fetus (noun.body)

part meronym	:	placenta,
definition	:	the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus (noun.body)