Il6 NORTH AMERICAN DIPTRRA. 



SUBGENERA OF CERA'fOPOGON. 



a. Wings bare Atrichopogon Kieffer. 



Wings hairy. . b. 



1). Hind metatarsus longer than the following joint, sometimes in 

 the male only equal. .... Ceratopogon. 



c. Hind metatarsus shorter than the following joint, sometimes 

 equal in the female. . . . Forcipomyia Megerle. 



Empodinm not so distinct, less than half as long as the claws, the 

 latter with setae at base; hind metatarsus always longer than 

 the following joint. (Oecacta is probably a synonym) (4). 



Culicoides Latreille. 



28. A cross-vein between the first and third veins. ... 29 

 No cross-vein between the first and the third veins. Bezzia Kieffer. 



SUBGENERA OF BEZZIA. 



a. Femora without prominent spines on the underside. 



Probezzia Kieffer. 



b. Some or all femora with spines Bezzia. 



29. Femora unarmed, that is without stout black spines on the under 



side (Ceratolophiis Kieffer.) (5) Johannseniella Williston. 



Some or all the femora spinose beneath. .... 30 



30. Hither fore or hind femora much thickened. . . . 31 

 Femora not noticeably thickened (1O) . Palpomyia Megerle. 



SUBGENERA OF PALPOMYIA. 



a. Antennae of both sexes verticillate with short hairs. 



Alasion Rondani. 



Antennae of the male plumose. b. 



b. Last tarsal joint with two rows of coarse spines below. 



Sphseromyas Stephens. 



Last tarsal joint hairy below. . . Palpomyia Megerle. 



31. Fore femora thickened. , Heteromyia. 

 Hind femora thickened. .... Serromyia Megerle. 



ADDITIONAL GENERIC REFERENCES FOR THE CHIRONOMID^). 



Johannsen. Bui. 86. N. Y. State Museum 1905. (Ablabesmyia, Ana- 

 topynia) . 



Kieffer. Bui. Soc. Entom. France. 1899. 



Ann. Soc. Sc. Brux. XXX. 1906. 

 " Genera Insectorum. Chironomidae. 1906. 



Latrielle. Gen. Crust, et Ins. IV. 1809. (Culicoides.) 



Megerle. In Meigen's System. Beschr. Eur. Zweifl. I. 1818. (For- 

 cipomyia, Serromyia, Palpomyia). 



Rondani. Prodromus. II. 1857. (Alasion). 



Skuse. Proc. Linn. Soc. N. S. Wales. IV. 1889. (Procladius, Iso- 

 plastus) . 



Stephens. Catalogue Brit. Ins. II. 1829. (Sphaeromyas.) 



Williston. Journal N. Y. Ent. Soc. XV. March, 1907. 



