Genus Heynsaxonchium
Coomans & Nair, 1975
Diagnosis:  Large nematodes (2.3-3.1 mm long), with C-shaped body.  Lateral and ventral body pores quite numerous.  Lip region offset with low conoid lips.  Odontostyle long and narrow, with minute aperture.  Guiding ring "double".  Anterior part of oesophagus slender but muscular, with fusiform section in front of nerve ring.  Two parts of oesophagus separated by long isthmus-like section.  Muscle bundles of oesophageal sheath dextrally spiral, but sinistrally spiral in anteriormost part.  Anterior genital branch of female long (about four body widths).  Vulva a transverse slit.  Vaginal wall very narrow distally, but very thick proximally, without sclerotisation.  Males with spaced ventromedian supplements.  Spicules very stout.  Tail hemispherical, similar in sexes.

Type and only speciesHeynsaxonchium dolichodorum (Coomans and Nair, 1975) Jairajpuri and Dhanachand, 1979.
Syn.: Axonchium (Heynsaxonchium) dolichodorum Coomans and Nair, 1975.

Remarks:  The subgenus Heynsaxonchium was raised to a genus by Jairajpuri and Dhanachand (1979).
(Description- Jairajpuri and Ahmad, 1992)