104 ILLINOIS BIOLOGICAL MONOGRAPHS [274 



EXPLANATION OF PLATE 

 Epipharynx and Hypopharynx and Associated Parts 



Fig- 493- Hypothetical type, lateral aspect. 



Fig. 494. Tabanus giganteus, female, lateral aspect. 



Fig. 495. Tabanus giganteus, male, lateral aspect. 



Fig. 496. Tabanus giganteus, female, caudal aspect. 



Fig. 497. Simulium venustum, female, lateral aspect. 



Fig. 498. Simulium venustum, female, caudal aspect. 



Fig. 499. Trichocera bimacula, lateral aspect. 



Fig. 500. Trichocera bimacula, caudal aspect. 



Fig. 501. Dixa clavata, lateral aspect. 



Fig. 502. Dixa clavata, caudal aspect. 



Fig. 503. Tipula bicornis, lateral aspect. 



Fig. 504. Psorophora ciliata, female, lateral aspect. 



Fig. 505. Psorophora ciliata, female, caudal aspect. 



Fig. 506. Geranomyia canadensis, lateral aspect. 



Fig. 507. Limnobia immatura, lateral aspect. 



Fig. 508. Rhyphus punctatus, lateral aspect. 



Fig. 509. Rhyphus punctatus, caudal aspect. 



