284 



— Femora without ventral spines 10 



8. Generally more than one pair of femora with spines; neither fore 



nor hind femora noticeably thickened Palpomyia. 



— Only fore or hind femora with spines, the spinose pair perceptibly 



thickened 9 



9. Fore femora thickened and spinose Hetcromyia. 



— ■ Hind femora much thickened and spinose Scrromyia. 



10. Media sessile J oJiannsenomyia. 



— Media petiolate Hartomyia. 



11. At least one pair of femora with ventral spines 12 



— Femora not spinose 13 



12. Media sessile Bezzia. 



— Media petiolate Pseudohezzia. 



13. Media sessile Prohezzia. 



— Media petiolate Parabezzia. 



N. B. The genus AtricJwpogon is distingiushed by the bare wings and distinct 

 empodia. I have no species belonging to this genus. 



When I wrote my paper on the Chironomidae of Illinois, in which 

 I included the present family as a subfamily of Chironomidae, I had 

 obtained data upon and materials representing the early stages of but 

 one species of Culicoidcs. In 191 6 I succeeded in obtaining a pupa 

 of another species in the Sangamon River, and the larvae and pupae 

 of one from water which had collected in a hollow tree-stump in the 

 forestry of the University of Illinois, at Urbana. These discoveries 

 prove that the genus is truly aquatic, as stated in my previous paper, 

 and ought to dispel the doubts of the fact that have been expressed by 

 some dipterologists. I was also successful in obtaining the larvae and 

 pupae of a species of Pseudocnlicoidcs from a wound on the trunk of 

 an elm tree on the university campus. The sap was flowing freely from 

 the wound, and associated w^ith this species were many larvae of 

 Mycetobia diver geiis, which superficially resemble those of Pseudo- 

 cnlicoidcs. The larvae of Culicoidcs and Pseudocnlicoidcs are very 

 similar to those of Palpomyia. The characters distinguishing them 

 will be dealt with in a future paper — provided I can command the time 

 necessary for the study. 



Family CHIRONOMIDAE 



In this paper I ha.ve included in this family only two subfamilies, 

 Tanypinae and Chironominae. 



