title: Ultrastructure of the egg shell of the acanthocephalan Neoechinorhynchus crassus.
abstract: In the acanthocephalan Neoechinorhynchus crassus five embryonic envelopes have been identified, including four, which are similar to those in previously studied acanthocephalans and a supplementary one, located between the outer and the second envelopes, which is characteristic of only a few Eoacanthocephala. The terminology of the envelopes in relation to their origin and possible function is discussed.
authors.affiliation: Laboratory of Ecology of Helminths, Institute of the Biological Problems of the North, Russian Academy of Sciences, Portovaja Street 18, 685000 Magadan, Russia. nikishin@ibpn.ru
authors.forename: V P
authors.initials: VP
authors.lastname: Nikishin
mesh_terms: D000049:Acanthocephala / Q000196:embryology* / Q000648:ultrastructure; D000818:Animals; D004625:Embryo, Nonmammalian / Q000648:ultrastructure*; D005260:Female; D010063:Ovum / Q000648:ultrastructure*; D009626:Terminology as Topic