19. Head with a narrow inconspicuous hyaline margin and 



small dorsal anterior plate LUNACEPS 



Head lacking the combination of characters of an 



inconspicuous hyaline and a small dorsal anterior 



plate 20 



20. Head with a dorsal anterior plate 21 



Head without a dorsal anterior plate 34 



21. Tergites divided medially 24 



Tergites not divided medially 22 



22. Dorsal transverse suture present at the level of 



the antennae; preantennal region rectangular CRASPEDONIRMUS 



Dorsal transverse suture absent at the level 



of the antennae; preantennal region trapezoidal CUMMINGSIELLA 



Tergites not divided medially; preantennal region 



rounded in front 23 



23. Dorsal surface of head without a transverse 



suture QUADRACEPS 



Dorsal surface of head with a transverse 



suture at or posterior to the antennae CARDUICEPS 



24. Tergites divided medially; head not rounded in 



front but rectangular or trapezoidal 25 



Tergites III-IV of ? divided medially; head ,, 



rounded in front BRUELIA 



25. Hyaline margin free throughout extent of 

 preantennal region; preantennal region apically 

 concave with a tuft of 3 or more long setae at 



each anterolateral angle CUCULOECUS 



Preantennal region without above combination 



of characters 26 



26. Slender body form; width of abdomen of 9 no 



wider than head 27 



Robust body form; abdomen of both sexes wider than 



head 28 



27. Terminal abdominal segment of d bilobed AQUANIRMUS 



Terminal abdominal segment of o* not bilobed MULCTICOLA 



28. Preantennal region rounded with a free hyaline 

 margin throughout; dorsal surface of head with 



peg-like spines ANATOECUS 



Preantennal region of head without above com- 

 bination of characters 29 



29. Premarginal bands and ventral bands of head 

 extending beyond anterior margin of dorsal 



anterior plate CRASPEDORRHYNCHUS 



Without above combination of characters 30 



67 



