Description (from Thorne, 1974)
Body practically straight when relaxed. Lateral field about 1/3 body width. Cuticle with minute radial striae. Lip region angular with prominent papillae, set off by constriction. Spear about 11 um long and 3 um wide with aperture occupying 2/3 its length. Pharynx 1/3 head width, the guiding ring about opposite the constriction setting off the lips. Esophagus enlarged in posterior 2/5 by rather abrupt expansion. Cardia elongate-hemispheroid, almost 1/3 body width. Vulva transverse with vagina walls merging with cuticle and no sclerotization. Ovaries sometimes crowded back to vulva by developing oocytes. Prerectum length 2 to 3 times body width. Tail dorsally convex-conoid to blunt terminus. One pair of caudal pores observed.
Habitat: From cultivated fields and prairie sod near Brookings, Parker, Mitchell and Rapid City, South Dakota.
-Thorne notes that Eudorylaimus dubius is distinctive among the small species by the long aperture of the broad spear. In this characteristic it resembles an Aporcelaimellus.