Description (from Thorne, 1974)
Body slightly arcuate. Anterior end set off by slight narrowing of neck. Cuticle of anterior end very thick, in two distinct layers. Spear 18 um long, the aperture occupying slightly more than 1/2 its length. Esophagus enlarged by very gradual expansion. Cardiac disc irregular in thickness. Cardia elongate conoid, enveloped by cells of anterior intestine. Vulva with massive, sclerotized labia. Ovaries reflexed 3/4 distance back to vulva. Eggs 1 1/2 times as long as body width and half as wide as long. Tail uniformly conoid to blunt rounded terminus with cuticle in two distinct layers, the inner one with strong radial striae. A single male bore 10 flat, elongated supplements.
Aporcelaimellus clamus is immediately distinguished from A. porcus by its uniformly conoid tail. Both species have the cardia surrounded by intestinal cells.
Habitat: Cultivated fields near Presho and Chamberlain, South Dakota.