78 



ILLIXOIS BIOLOGICAL MONOGRAPHS 



[248 



EXPLANATION OF PLATE 



Caudal and Lateral Aspects of the Head and the Tentorium 



Oecothea fenestralis, caudal aspect. 



Gasirophilus cqui, caudal aspect. 



Olfersia ardcac. caudal aspect. 



Hypothetical head, lateral aspect. 



Hypothetical tentorium, lateral aspect. 



Tabunus giganleus, female, lateral aspect. 



Tabanus giganteus, lateral aspect of the tentorium. 



Siitniliuiii vcnustum, female, lateral aspect. 



Leptis vcrtebrata, male, lateral aspect. 



Mydas clavatus, lateral aspect. 



Promachus vertebratus, lateral aspect. 



Promachus vertebratus, lateral aspect of the tentorium. 



Scenopinus fenestralis, female, lateral aspect. 



Sciara variaus, lateral aspect. 



Pipunculus cingulatns, lateral aspect. 



Chironoinus fcrrugincovittatus, lateral aspect. 



Bibio feiiioratus, female, lateral aspect. 



Bibio fciijoratus, male, lateral aspect. 



I 



