Nygolaimus obtusus
Thorne, 1930
Body almost straight when relaxed by gradual heat. Amphids obscure,
about one-third as wide as the head. First three sections of pharynx
forming a large cavity about one-third as wide as the head and twice as
long as wide. Ovaries reflexed one-third their length. Tail,
elongate-hemispherical. Lateral cords one-fifth as wide as the body
and conspicuous because of the large granules appearing in them.
Cardiac glands unusually small. Intestine three-fourths as wide as
the body, its cells densely packed with small granules. Anus depressed,
rectum one and one-third times as long as the anal body diameter.
Prerectum one and one-half times as long as the rectum. The elongate-hemispherical
tail bears two pairs of conspicuous pores, the posterior pair often showing
distinct connections with an internal glandlike body. Males unknown.
Habitat: A single collection of 12 specimens from a sugar-beet
field near Ogden, Utah, U.S.A. Most closely resembles Nygolaimus
aquaticus from which it is immediately distinguished by the distinctly
set off lip region.