74 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[244 



EXPLANATION OF PLATE 

 Caud.\l Aspect of the Head 



Bibio femoratus, male. 



Bibio femoratus, female. 



Limnobia immatura. 



Sphyracephala brcvicornis. , 



Tiptila bicornis. 



Psorophora ciliata, female. 



Enipis clausa, female. 



Exoprosopa fasciata. 



Mydas clavatus. 



Psilocephala haeiuorrhoidalis, female. 



Ochthera mantis. 



Lonchoptera Iiitea, female. 



Leptis vertcbrata, male. 



Stratiomyia apicula. male. 



Oncodes costatus. 



Pipuncuhis cingiilatus, female. 



Scenopinus fenestralis. 



Dolichopus sp. 



Oncodes costatus. ventral aspect. 



Platypeca vclutina. 



Aphiochaeta agarici. 



Dolichopus bifractits, lateral margins incomplete. 



