17. 



Genus Panayrobelus Thome, 1939 

 (Key to the species) 



Female 1.0 mm and male 0.9 nun in length; tt-ro pairs of preanal and 

 two pairs of postanal ventrosubmedian male papillae 



incisus Thome, 1939 



Male and female length 0.5 fnm; three pairs of preanal and three pairs 

 of postanal ventrosubmedian male papillae 

 coronatus (Fuchs, 1930) Thome, 1939 



Genus Macrolaimus Maupas, 1900 

 (Key to the species Allen, 1950) 



Male and female tails with terminal hook, lips forming high arch 



over vestibule hamatus Thome, 1937 



Tails without terminal hook, arch over vestibule slight 

 taurus Thome, 1937 



Other species: 



M. aculeatus (Daday, 190^) Thome, 1937 



M. crucis Maupas, 1900 



M. papillatus (Rahm, 1928) Goodey, 1951 



Genus Tricephalobus Steiner 

 Contains : 



T. acuminatus (Kreis, 1929) Goodey, 1951 

 T. labiatus CKreis, 1929) Goodey, 1951 

 T. longicaudatus Steiner, 1936 



Genus Fleet on chus Fuchs, 1930 



Contains : 



P. atari Fuchs, 1930 



P. cuniculari Fuchs, 1930 



P. ligniperdae Fuchs, 1930 



All three species occurred in the frass of bark beetles in Europe, 



Genus Neocephalobus (Steiner, 1929) Steiner, 193U 



[Key to species) 



Three lips, each consisting of 2 more or less distinctly amalga- 

 mated lips; in male ventromedian papilla adanal 



peruensis Steiner, 1939 



Six uniform lips; in male ventromedian papilla in latitude of 

 proximal end of spicula . . . . ' aberrans (Steiner, 1929) Steiner, 193U 



