78 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[248 



EXPLANATION OF PLATE 

 Caudal and Lateral Aspects of the Head and the Tentorium 



Oecothea fenestralis, caudal aspect. 



Gastrophilus equi, caudal aspect. 



Olfersia ardeae, caudal aspect. 



Hypothetical head, lateral aspect. 



Hypothetical tentorium, lateral aspect. 



Tabanus giganteus, female, lateral aspect. 



Tabaiius giganteus, lateral aspect of the tentorium. 



Siinulium venustum, female, lateral aspect. 



Leptis vertebrata, male, lateral aspect. 



Mydas clavatus, lateral aspect. 



Proviachus vertebratus, lateral aspect. 



Promachus vertebratus, lateral aspect of the tentorium. 



Scenopiuus fenestralis, female, lateral aspect. 



Sciara various, lateral aspect. 



Piptmcuhis eiiigulatus, lateral aspect. 



Chironomus ferrugineovittatus, lateral aspect. 



Bibio fciuoratus, female, lateral aspect. 



Bibio feiiwratiis, male, lateral aspect. 



