Genus Trefusialaimus Riemann, 1974
Type species
Trefusialaimus monorchis Riemann, 1974
Diagnosis
Sub-cephalic and somatic setae absent. Ten cephalic setae in one circle; amphid pocket-shaped. Male with one testis and peri-cloacal papillae. Elongated sperm cells with central rod and light-refractive nucleus at one extremity. Tail conico-cylindrical or filiform.