7R. 



Subfamily MOKHYSTEKINA'? 

 (Key to the genera modified from Wieser, 1956) 



1. Six large, se rented cephalic setae present 2 



Ten cephalic setae or more present; if seemingly only six, then 

 papillose or indistinct, not segnented 3 



2. Female with one posterior reflexed ovary .... Rhabdoeoma Cobb, 1920 

 Female with two out-stretched ovaries Cytolainiiijin Cobb, 1920 



3. Amphid an open spiral Spiramphinema Wieser, 19^6 



Amphid circular or cryptospiral U 



U. Stoma armed with three teeth or denticles 5 



Stoma imarmed 6 



5. Stoma armed with three teeth Cobbia de Man, 1907 



Stoma armed with three denticles Monhystrella Cobb, 1918 



6. Amphids vesicular, convex, thin-walled (hence sometimes indistinct). 7 

 Amphids not vesicular, concave, thick-walled (always distinct). . . 9 



7. Amphids circular; labial setae very long. . Proironhystera Wieser, 1956 

 Amphids circular to transversely elliptical or irregular to 

 longitudinally elliptical; labial setae not elongate 8 



8. Amphids circular to transversely elliptical; gubemaculum tubular 



Paranionhystera Steiner, 1916 



Amphids irregular to longitudinally elliptical, especially large; 

 gubemaculum absent Amphimonhystera Allgen, 1929 



9. Stoma tubular, very deep Rhynchonema Cobb, 1920 



Stoma cup-shaped, shallow 10 



10. Cuticle striated .11 



Cuticle smooth 13 



11. Eight groups of subcephalic setae articulate on the same level as the 

 cephalic setae, giving the impression of 8-radiate symmetry of the 



latter Steineria Micoletzky, 1921 



If 8 groups of subcephalic setae present, then always articulating at a 

 considerable distance behind the cephalic setae; the 6- radiate 

 symmetry of the latter always obvious .... 12 



12. Esophagus differentiated in posterior portion . Austronema Cobb, 1911| 

 E3ophagus undifferentiated throughout .... Theristus Bastian, 1865 



13. Stoma simple. . . . ^ Monhystera Bastian, 1865 



Stoma consisting of two small cavities in tandem 11+ 



