96 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[266 



EXPLANATION OF PLATE 



Maxillae and Labium 



Chironomns j crrugincovittatus , cephalic aspect. 

 Psychoda albipennis, cephalic aspect. 



Psorophora ciliata, female, portions of mandibles, maxillae, labium, ten- 

 torium, and head-capsule. 

 Rhyphus punctatus, cephalic aspect. 

 Dixa clavata, cephalic aspect. 

 Promachus vertebratus, caudal aspect. 

 Promachus vertebratus, labium, cephalic aspect. 

 Promachus vertebratus, cross-section of labium, see figure 377. 

 Promachus vertebratus, distal end of labium, cephalic aspect. 

 Psorophora ciliata, distal end of labium, caudal aspect. 

 Psorophora ciliata, distal end of labium, cephalic aspect. 

 Geranomyia canadensis, cephalic aspect. 

 Tipula bicornis, distal end of labium, mesal aspect. 

 Tipula bicornis, caudal aspect of labium. 

 Helobia punctipennis, caudal aspect. 

 Limnobia immatura, caudal aspect. 

 Dixa clavata, caudal aspect of labium. 



Tipula bicornis, sclerites about distal end of theca of labium. 

 Bittacomorpha clavipes, distal end of labium, mesal aspect. 

 Tabanus giganteus, mesal aspect of labium. 

 Tabanus giganteus, caudal aspect of labium. 

 Tabanus giganteus, cephalic aspect of labium. 

 Aphiochaeta agarici, caudal aspect. 

 Aphiochaeta agarici, distal end of labium, mesal aspect. 



