1	- Longer odontostyle, more than 30 μm	2
	- Shorter odontostyle, equal or less than 22 μm	4
2	- Longer odontostyle, 41 μm long; and comparatively shorter female tail, c′ = 1.0	crassatum
	- Shorter odontostyle, up to 38 μm; and comparatively longer female tail, c′ ≥ 1.6	3
3	- Odontostyle 35–38 μm long or 2.6–2.7 times the lip region diameter; comparatively longer neck in females, b = 3.1–4.0; comparatively shorter female tail, c′ = 1.6–1.7; and male absent	caudatum
	- Odontostyle 31–35 μm long or 2.0 times the lip region diameter; comparatively shorter neck in females, b = 4.0–4.9; comparatively longer female tail, c′ = 2.0; and male present	proamphidum
4	- Body 1.36–1.60 mm long and very slender, a = 48–59; vulva more posterior, V = 59	longum
	- Body up to 1.30 mm long and less slender, a up to 45; vulva less posterior, V = 51–56	5
5	- Shorter odontostyle, 13–15 μm long; and male present	secutum
	- Longer odontostyle, equal or more than 15 μm long; and male absent	6
6	- Lip region 9–10 μm broad; odontostyle aperture occupying 20% of total odontostyle length; and double guiding ring	tenue
	- Lip region 10–11 μm broad; and odontostyle aperture occupying 25–35% of total odontostyle length; and simple guiding ring	farodai