48 THE CANADIAN ENTOMOLOGIST. 



In tabular form we recognize the following genera. We have 

 employed one new character, the tibial comb or scraper, a microscopic 

 structure situated at the end of the tibiae, and consisting of a row of fine 

 spines. It apparently functions as a cleansing organ for the body parts 

 or wings. 



CULICINI. 



1. Scutellum evenly rounded, not lobed 2. 



Scutellum distinctly trilobed 3. 



2. First submarginal cell longer than its petiole Atiopheles. 



First submarginal cell less than half as long as its petiole. Megar/iinus. 



3. Hind tibial scraper with a row of 7 to 12 closely set setae 4. 



Hind tibial scraper with none to 5 sparsely set seta? 13. 



4. Scutellum with central lobe elongate, collar-like, not tubercularly 



prominent 5. 



Scutellum with central lobe distinctly prominent and tubercular ... 6. 



5. Terminal antennal joints slender, long Mansofiia. 



Terminal antennal joints short, broad y^deomyia. 



6. Second joint of antenniie very long, 14x1 Deinoceriies. 



Second joint of antennae moderate, less than 8x1 7. 



7. First submarginal cell less than half as long as its petiole. Urafiotania. 

 First submarginal cell at least nearly as long as its petiole 8. 



8. Head with a distinct neck, the occiput broad and 



exposed Psorophora. 



Head without a distinct neck, appressed to the thorax 9. 



9. Cross veins tending to lie in line, the third separated from the second 



by less than its own length Culiseta. 



Cross veins normal, widely separated, the third distinct from the 



second by its own length 10. 



ID. 9 with the last segment of the abdomen not extensile, large, squarely 

 ended ; $ genitalia with the harpes slender, columnar with bent 



spined tip . . ; ... Tceniorhytichus. 



9 with the last segment of the abdomen extensile, slender ; $ 



genitalia with harpes broad, concavely curved i r. 



r I. Clypeus bare 12. 



Clypeus with dense appressed scales Stegomyia. 



I 2. Prothoracic lobes approximate Bcemagogtis. 



Prothoracic lobes well separated ^des. 



13. Feet with large empodia Lutzia. 



Feet with small empodia Culex. 



