Definition: Belonolaiminae. Head offset, annulated,
4-lobed. Spear very long. Procorpus with long coiled lumen.
Dorsal oesophageal gland opening close to spear base. Ovate median
bulb clearly set off, wth large crescentic valve plates. Isthmus
short, expanding to a spathulate glandular lobe overlapping the intestine.
Lateral field absent save for a median line. Female tail cyindrical,
about 3 body-widths long with rounded tip; phasmids about 1/2 tail-length;
gonads paired, opposed, outstretched; spermathecae present. Male
tail long, surrounded by voluminous bursa; phasmids 1/3 tail-length.
Spicules arcuate with ventral flanges. Gubernaculum with titillae.
(Description- Goodey, 1963)
Belonolaiminae. SEM face view shows a well marked, rounded labial disc,
and first lip annulus divided into six sectors, lateral sectors almost
completely regressed, seen only as small interruptions of the first one
or two labial annuli. Labial region marked by deep longitudinal grooves.
Stylet very long, 60-150 um long, its cone 70-80% of total stylet length.
Corpus as in Morulaimus. Oesophageal glands overlapping beginning
of intestine. Female tail cylindroid with a broadly rounded terminus. Lateral
field with four lines or less.
(Description- Fortuner and Luc, 1987)
Type Species: Belonolaimus gracilis Steiner, 1949