Body slightly arcuate,
cylindroid, tapering gradually at extremities. Lip
region very angular, set off by expansion, with prominent papillae.
Spear 15 um long
with aperture occupying 1/3 its length. About 2/5 of esophagus enlarged
by rather abrupt expansion. Cardia
discoid, then conoid or spheroid. Intestine thin-walled with scattered
dark brown refractive granules. Vulva
transverse with slightly sclerotized labia. Vagina spheroid, only
about 1/3 as long as body width. Ovaries reflexed about halfway to
vulva. Eggs 30 x 70 um. Prerectum 2 to 3 times as long
as body width. Rectum about equal to anal body diameter. Males
Eudorylaimus aquilonarius is distinctive because of its angular, expanded lip region, posteriorly located vulva, form of vulva labia, spheroid vagina and arcuate tail with small rounded terminus.
Habitat: Grain field near Fargo, North Dakota, and soil about roots of juniper in windbreak near Forestburg, South Dakota.