24 Journal New York. Entomological Society. [Vol. xiil 



15. Anal segment ringed ; ventral tufts to the base ; tube inflated 16. 



Without this combination of characters ; tube not inflated 19. 



16. Antennae long ; anal segment long and slender 17. 



Antennae moderate ; anal segment short, wider than long 18. 



17. Comb of the eighth segment of six or seven subequal spines. 



J a nth in osoma m usicu m . 

 Comb of five spines, the upper and lower small Janthinosoma zaripes. 



18. Antennae black on outer half ; the four spines of air tube scattered to basal half. 



Grabhamia jamaicensis. 

 Antenna; all white ; the four spines of air tube restricted to basal third. 



Ticniorhynchus signipennis. 



19. Anal segment not ringed ; usually with slight tufts before the barred area 20. 



Anal segment ringed ; no tufts before the barred area 24. 



20. Spines of the comb produced, elongate, blunt Culex triseriatus. 



Spines not produced, short, thorn-shaped 21. 



21. Tuft of tube within the pecten ; tube with dorsal tufts. Culex trichurus.* 



Tuft of tube beyond the pecten, no other tufts 22. 



22. Tuft of tube beyond the outer third ; anal processes pointed Aedes fuscus. 



Tuft of tube before outer third ; anal processes blunt 23. 



23. Anal plate longer than wide from side view, sharply incised subdorsally. 



Culex impiger. 

 Anal plate wider than long ; no marginal incision Culex sylvestris. 



24. Tube twice as long as wide or more; comb of nearly simple spines 25. 



Tube one and a half times as long as wide ; comb of spined teeth 28. 



-25. Comb of four to twelve teeth, large, thorn-shaped 26. 



Comb a small patch of spines 35- 



26. Anal processes long; tube not functional ; larvae aquatic Culex a'upreei. 



Anal processes normal ; tube functional 27. 



27. Tuft of tube beyond the middle but within the pecten ; anal processes with 



apical half constricted Culex serratus. 



Tuft of tube before the middle but beyond the pecten Culex punctor. f 



28. Comb of digitately spined teeth in a small patch 36. 



Comb of elongate teeth with central longer spine Stegomyia fasciata. 



29. Pecten of the air tube a row of hairs outwardly 30. 



Pecten of the air tube of toothed spines entirely 31. 



30. Chitinized parts heavily infuscated, robust Iheobaldia incidens. 



Chitinized parts usually weakly infuscated, less robust. 



Scales of comb about 60 ; air tube pecten with 1 or 2 teeth. 



( 'ulex consofa-inus, Culex magnipennis. 

 Scales of comb about 40 ; pecten with 2 or 3 teeth Culex absobrinus. 



31. Anal segment ringed by the plate 3 2 - 



Anal segment not completely ringed or with dorsal plate only 37. 



32. Anal processes absent; pecten of the air tube furcate Deinocerites cancer. 



Anal processes present ; pecten of the air tube serrate ^- 



* Synonym, C. cinei eoborealis Felt & Young. 

 f Synonym, C. abserratns Felt& Young. 



