log NORTH AMERICAN DIPTERA. 



9. Head with a distinct neck, the occiput broad and exposed (fig. 34) . 



Psorophora. 

 Head without distinct neck, appressed to the thorax. . 10 



10. Cross-veins approximated and nearly in line with the ha<-al sec- 



tion of the third vein. ... . Culiseta. 



Cross-veins not approximated, separated by at least the length of 



the posterior. ......... 1 1 



11. L,ast segment of the female abdomen not extensile, large, trun- 



cate; male genitalia with the harpes slender, columnar, with 



bent, spined tip Tseniorhynchus. 



Last segment of the female abdomen extensile, slender; male 

 genitalia with harpes broad, concavely curved. . . 12 



12. Clypeus bare. ......... 13 



Clypeus with dense appressed scales. . . . Stegomyia. 



13. Prothoracic lobes approximated (4,5). . Hsemagogus. 

 Prothoracic lobes well separated (figs. 32, 33). . Aedes. 



14. Empodia large. ........ Lutzia. 



Empodia small (fig. 30). ...... Culex. 



15. Clypeus without hairs. ........ 16 



Clypeus hairy on the sides. ..... Joblotia. 



16. Prothoracic lobes contiguous, densely hairy. . Sabethes. 

 Prothoracic lobes well separated. . . . . . .17 



17. Eyes narrowly separated by the front; proboscis rather short, 



swollen at tip. ......... 18 



Eyes contiguous at vertex. ....... 19 



18. Hind tarsi with two claws, normal (6). . . Wyeomyia. 

 Hind tarsi with but a single claw. . . . Limatus. 



19. No erect forked scales on occiput; proboscis longer than the body. 



Phoniomyia. 



With a row of erect forked scales on occiput; proboscis not longer 

 than the body. ......... 20 



20. Face normal, smooth. .... Lesticocampa. 

 Face with a conical process above the clypeus. Runchomyia. 



The following synonymy is given by Dyar and Knab: 



Anopheles Meigen: Myzomyia Blanch., Cycloleppteron Theob: 

 Nototricha Coq., Cellia Theob., Arribalzagia Theob., Coelodiazesis 

 D. and K. 



Mansonia Blanch.: Pneuinaculex Dvar. 



