794 CHAKLES PAUL ALEXANDER 



4. Head capsule massive, compact, the posterior incisions usually shallow 5 



Head capsule of four or six slender rods, the posterior incisions profound 15 



5. Mentum completely divided, a toothed plate on either side; abdominal segments without 



distinct creeping-welts -6 



Mentum, if present and chitinized, not completely divided; abdominal segments with 

 basal creeping-welts 8 



6. Spiracular disk squarely truncated, surrounded by five lobes Eriopterini (p. 908) 



Spiracular disk with four lobes 7 



7. Each mental plate four-toothed; hypopharynx labriform. 



Pediciini, subtribe Adelphomyaria (p. 895) 

 Each mental plate with seven or eight teeth; hypopharynx a comblike ring. 



Hexatomini, subtribe Pseudolimnophilaria (p. 848) 



8. Spiracular disk with five lobes 9 



Spiracular disk with four lobes 12 



9. Antennae almost globular, with two conical apical papillae; lives in fungi. 



Hexatomini, subtribe Ularia (p. 838) 

 Antennae elongate-cylindrical 10 



10. Abdomen with dorsal and ventral creeping-welts; mentum with more than five teeth. 



Limnobiini (p. 795) 

 Abdomen with six ventral welts only; mentum with five or fewer teeth 11 



11. Mentum five-toothed; lives in earth Limnobiini, subtribe Rhamphidaria (p. 830) 



Mentum three-toothed; lives in wood Hexatomini, subtribe Epiphragmaria (p. 843) 



12. Antennae almost globular, with two conical apical papillae; lives in fungi. 



Hexatomini, subtribe Ularia (p. 838) 

 Antennae elongate-cylindrical 13 



13. Abdomen with dorsal and ventral creeping-welts, the latter naked; mentum not three- 



toothed; forms aquatic Limnobiini, subtribe Ellipteraria (p. 806) 



Abdomen with ventral creeping-welts only; mentum with only three primary teeth; 

 species not aquatic 14 



14. Form long, slender; skin naked, shiny, transparent; apical segment of antennae elongate, 



as long as, or longer than, basal segment; mentum with a smaller tooth on either side; 



lives in earth Limnobiini, subtribe Dicranoptycharia (p. 828) 



Form short, stout; skin white, opaque; apical segment of antennae short, hemispherical; 

 mentum without small lateral teeth; lives under bark. 



Hexatomini, subtribe Epiphragmaria (p. 843) 



15. Blades of maxillae not produced; form long and slender 16 



Blades of maxillae produced into flattened elongate appendages, the tips of which pro- 

 trude from the thoracic orifice when the head is completely retracted; form short 

 and stout 17 



16. Spiracular disk squarely truncated, surrounded by five lobes which are fringed with 



numerous, usually short, hairs; esophageal region not conspicuously grooved. 



Eriopterini, subtribe Eriopteraria (p. 911) 



Spiracular disk surrounded by four lobes, each ventral lobe with a single elongate bristle; 

 esophageal region elongate, grooved; lives under bark. 



Eriopterini, subtribe Elephantomyaria (p. 952) 



17. Mental region a narrow, transverse, chitinized bar. 



Hexatomini, group Limnophilae (p. 858) 

 Mental region not chitinized 18 



18. Mandibles hinged; maxillae and labrum densely hairy; dorsal plates of head, capsule 



united into a spatula Hexatomini, group Ulomorphae (p. 869) 



Mandibles not hinged; maxillae and labrum not densely hairy; dorsal plates of head 

 capsule separated Hexatomini, subtribe Hexatomaria (p. 876) 



19. Head capsule massive, compact 20 



Head capsule of six slender rods; lives under bark. 



Eriopterini, subtribe Eriopteraria (p 911) 



