131. 



18 » Lip region continuous with neck contours, <, , , . 19 



Lip region set off by expansion or narrowing. ........... 20 



19. Tail concave conoid, attenuated •...<> . omer-cooperi Filipjev, 1931 

 Tail uniformly conoid chitwoodi Moorthy, 1937 



20 o Lip region distinctly expanded » , 21 



Lip region slightly expanded or narrowed .... 22 



21. Length over U.O mm macrolaimus (de Man, 188U) Steiner, I9I6 



Length under 2.0 mm elaboratus (Cobb, I906) T. & S., 1936 



22. Vulva near 38^ nudus Wu and Hoeppli, 1929 



Vulva from U5-53^ , . 23 



23. Tail concave conoid occaleecens Schneider, 1937 



Tail imiformly conoid ..2U 



2U. Tail comparatively short, c = 18.5 cinctus Thome, 1939 



Tail longer, c=ll propinquus Cobb, M.V., 1915 



25. Supplements questionable, not seen nudus VJu and Hoeppli, 1929 



Supplements known . ....25 



26. Supplements in fascicles .27 



Supplements solitary. .. 29 



27. Tail elongate, bluntly conoid omer-cooperi Filipjev, 1931 



Tail hemispheroid 28 



28. Pharyngeal walls lightly cuticularized posterior to onchia 



michaelseni Steiner, I9I6 



Pharyngeal walls heavily cuticularized throughout .29 



29. Vulva G^% hut chins oni Filipjev, 1929 



Vulva 38$2 . tenuis Schneider, 1935 



30. Supplements contiguous 31 



Supplements separated by short spaces 33 



31. Lip region set off by very slight expansion 



occalescens Schneider, 1937 



Lip region set off by broad expansion ...32 



32. Body length near \\,0 mm . . . macrolaimus (de Man, I88U) Steiner, I9I6 

 Body length near 2.5 mm . cyatholaimus (Daday, 1905) Th. & Swang., 1936 



33. Pharyngeal walls ribbed surenamensis Micoletzky, 1925 



Pharyngeal walls massively cuticularized. . ruwenzarii de Coninck, 1935 



Other species: A. frostae Allgen, 1952 



