Body colorless, slender, tapering uniformly both ways from the vulva.
Lip region tapering rapidly, somewhat angular. Amphid apertures broad,
crescentic, slit-like, always seen in partial profile due to natural twisting
of the body. Sensillae opposite the obscure excretory pore.
Esophagus at first gradually narrowed, then becoming a slender tube which
is one-fourth the neck width at the nerve ring, finally widened in the
basal fourth by a gradual expansion until about half the neck width. Tail
slightly arcuate, somewhat convex-conoid in its terminal fourth.
A single gravid female from Virginia was slightly wider, a = 67; and the ovaries were longer, 14% and 12 %. An egg was 31/2 times as long as the body width.
Diagnosis: Amphidelus with the above measurements and general description. A close relative of Amphidelus sylphus, from which it differs in its smaller size, greater width and straighter tail . It is possible that this actually is a soil adapted form of A. sylphus.
Habitat: Eight females and five young from soil about roots of alpine plants, summit of Mt. Timpanogos, 12,000 feet, and Mt. Deseret, 11,000 feet, Utah. One female from stream bank soil, Broad Run, near Leesburg, Virginia, U.S.A.
(Description- Thorne, 1939)