1.	Supplementary organ present in males …5
	-Supplementary organ absent in males …2
2.	Stout post-cloacal setae present …M. africanthiforme
	-Stout post-cloacal setae absent …3
3.	Tail conico-cylindrical …M. karense
	-Tail conical …4
4.	Tail long (c =14–19) with typical stoma …M. audax
	-Tail stout (c= 43–51) with well-developed posterior rods of the stoma … M. armatum
5.	Gubernaculum present in males …11
	-Gubernaculum absent in males …6
6.	Body length over 3000 µm …7
	-Body length below 2000 µm …8
7.	Several cervical setae at cephalic capsule with spicules arrow shape with sharp distal end …M. agubernatus
	-No cervical setae at cephalic capsule with simple spicules slightly curved with blunt distal end …M. studiosum
8.	Mandible decorated by longitudinal marks …M. rigens
	-Mandible with no decoration …9
9.	Somatic setae absent …M. proximum
	-Somatic setae present …10
10.	Dorsal tooth missing …M. monhystera
	-Dorsal tooth present …M. hirsutum
11.	Enlarged cervical setae (flaps) present below lateral outer labial seta at posterior end of cephalic capsule …12
	-Enlarged cervical setae (flaps) absent …13
12.	Inner labial setae stout. Index c’ 4.0–5.7 …M. jejuensissp. nov.
	-Inner labial setae thin. Index c’ 3 …M. pannosum
13.	Subventral precloacal setae absent …14
	-Subventral precloacal setae present …18
14.	Gubernaculum triangular …15
	-Gubernaculum simple with dorsal appendage …M. marisalbi
15.	Gubernaculum with two parts; membranous part and rod-like part which supports it caudally with barbed tip …M. virile
	-Gubernaculum with just one part …16
16.	Spicule bipartite …M. ditlevseni
	-Spicule unipartite …17
17.	Subcephalic setae absent, supplementary organ 2.2 abd away from anus … M. breviseta
	-Four subcephalic setae very thin near end of cephalic capsule, supplementary organ 3 abd away from anus …M. lucifer
18.	Proximal end of spicule with massive process …M. fricum
	-Proximal end of spicule without massive process …19
19.	Distal end of spicule with backwardly pointing spines …M. audax
	-Distal end of spicule with no backwardly pointing spines …20
20.	Spicule distally dilated …M. majus
	-Spicule with no dilation …21
21.	Supplementary organ located close (∼1 spicule length) to proximal end of the spicule …M. kerguelense
	-Supplementary organ located further (>1.1 spicule length) away from the anus …22
22.	Inner labial setae stout 12 µm long, Index a ∼30, Index b ∼5, Index c’ 4.2–4.5 …M. longissimesetosum
	-Inner labial setae stout 24 µm long, Index a ∼50, Index b ∼3, Index c’ 2.8 … M. pali