title: [Characteristics of the fine structure of embryonic membranes in the spiny-headed worms of the class Eoacanthocephala, by an example of the spiny-headed worm species Neoechinorhynchus crassus].
abstract: Five embryonic membranes are found in the spiny-headed worm species Neoechinorhynchus crassus. Four embryonic membranes are analogous to the membranes in all other spiny-headed worms studied, and one membrane is additional. The last is situated between the external and second membranes and is characteristic only for some species of the class Eoacanthocephala. Terminology of the embryonic membranes in connection with their origin and possible functional significance is discussed.
authors: V P
authors: VP
authors: Nikishin
mesh_terms: D000049:Acanthocephala / Q000196:embryology* / Q000648:ultrastructure; D000818:Animals; D005260:Female; D008566:Membranes / Q000648:ultrastructure; D010063:Ovum / Q000648:ultrastructure