94 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[264 



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EXPLANATION OF PLATE 



Mouth-parts 



Sarcophaga liacmorrhoidalis, lateral aspect. 



Musca domestica, lateral aspect. 



Empis clausa, lateral aspect. 



Archytas analis, lateral aspect. 



Stomoxys calcitrans, lateral aspect. 



Siplwna geniculate!, lateral aspect. 



Conops brachyrhynchus, lateral aspect. 



Scatophaga furcata, lateral aspect. 



Olfersia ardeae, lateral aspect. 



Stylogaster bianniilata, caudal aspect. 



Sciara various, maxillae and labium, cephalic aspect. 



Exoprosopa fasciata, lateral aspect. 



Hypothetical and typical labium, mesal aspect. 



Hypothetical mouth-parts, lateral aspect. 



Bibio femoratus, maxillae and labium, cephalic aspect. 



Eulonchus tristis, head and mouth-parts, lateral aspect. 



Trichocera bimacula, maxillae and labium, cephalic aspect. 



Simulium venustum, maxillae and labium, cephalic aspect. 



Rhabdophaga strobiloides, maxillae and labium, caudal aspect 



Leia oblectabilis, maxillae and labium, cephalic aspect. 



Leptis vertcbrata, mesal aspect of glossa. 



Leptis vertebrata, maxillae and labium, caudal aspect. 



