Genus Ironus
Bastian, 1865
Syn. Cephalonema Cobb, 1893 nec Stimpson,
1857
Nanonema Cobb in Stiles & Hassall,
1905
GEN. CHAR. Body long and narrow, tapering at extremities.
Caudal sucker absent. Integument with delicate longitudinal
markings; cephalic setae present. Pharyngeal cavity long and
narrow, having three small, movable, rounded projections near commencement.
Oesophagus cylindrical, canal indicated by three bright lines; transverse
muscular fibres not distinct. Intestine moderately well covered
with hepatic cells containing light-coloured fat-particles indistinctly
aggregated. Vulva about the middle of the body. Uterus
bifid, segments suymmetrical. Spicules-------?
Lateral canals-------? Movements very sluggish.
(Description- Bastian, 1865)
Definition: Ironinae. Body slender. Cuticle without
striations, setae or lateral alae. Head offset by shallow constriction
with 3 movable lips each with a small apical
papilla and 4 submedian setae. Amphids cup-like at level of head
setae, apertures slit-like. Stoma long, tubular, with 3 anterior
eversible hook-like teeth.
In developing forms the 3 teeth are situated a little further posteriorly.
Excretory pore in vicinity of lips. Oesophagus almost cylindrical
but a little wider behind than in front. Vulva
equatorial; gonads paired, opposed and reflexed. Spicules paired,
arcuate, strong, with a central strengthening piece. Gubernaculum
small. Caudal glands and terminal duct probably absent. Tail
tapering
to fine point in both sexes. A single mid-ventral seta present on
male; other caudal papillae absent.
Type species: Ironus ignavus Bastian, 1865
DNA Sequences obtained