74 ILLINOIS BIOLOGICAL MONOGRAPHS [244 



EXPLANATION OF PLATE 

 Caudal Aspect of the Head j 



Fig. 91. Bibio femoratus, male. 



Fig. 92. Bibio femoratus, female. 



Fig. 93. Limnobia immatura. 



Fig. 94. Sphyracephala brevicomis. 



Fig. 95. Tipula bicornis. 



Fig. 96. Psorophora ciliata, female. 



Fig. 97. Empis clausa, female. 



Fig. 98. Exoprosopa fasciata. 



Fig. 99. Mydas clavatus. 



Fig. 100. Psilocephala haemorrhoidalis, female. 



Fig. loi. Ochthera mantis.  



Fig. 102. Lonchoptera lutea, female. 



Fig. 103. Leptis vertebrata, male. 



Fig. 104. Stratiomyia apicula, male. 



Fig. 105. Oncodes costatus. 



Fig. 106. Pipunculus cingulatus, female. 



Fig. 107. Scenopinus fenestralis. 



Fig. 108. Dolichopus sp. 



Fig. 109. Oncodes costatus, ventral aspect. 



Fig. no. Platypeza velutina. 



Fig. HI. Aphiochaeta agarici. 



Fig. 112. Dolichopus bifractus, lateral margins incomplete. 



