A class of nematodes lacking lateral canals opening into the excretory system and phasmids, with few or no caudal papillae, eggs unsegmented, and with polar plugs or hatching in utero. It includes the genera Trichuris, Capillaria, and Trichinella among important parasites of man and domestic animals. See Also: Secernentasida. Syn: Adenophorea, Aphasmidia.
Origin