106 ILLIXOIS BIOLOGICAL MONOGRAPHS [276 



EXPLANATION OF PLATE 

 Epipharynx and Hypopharynx and Associated Parts 



Fig. 510. Rhabdophaga strobiloides, caudal aspect. 



Fig. 511. Rhabdophaga strobiloides, lateral aspect. 



Fig. 512. Sciara varians, caudal aspect. 



Fig. 513. Sciara varians, lateral aspect. 



Fig. 514. Periplaneta orientalis, clypeus, labrum, and epipharynx spread out, ental 



aspect. 



Fig. 515. Melanoplus differ entialis, clypeus, labrum, and epipharynx spread out. 



ental aspect. 



Fig. 516. Gryllus pennsylvanicus, right-half of clypeus, labrum, and epipharynx, 



cephalic and caudal aspects. 



Fig. 517. Promachus vertebratus, lateral aspect. 



Fig. 518. Promachus vertebratus, epipharynx and labrum, caudal aspect. 



Fig. 519. Promachus vertebratus, caudal aspect. 



Fig. 520. Leptis vertebrata, lateral aspect. 



Fig. 521. Culicoides sanguisugus, lateral aspect 



Fig. 522. Bibio femoratus, caudal aspect. 



Fig. 523. Bibio femoratus, lateral aspect. 



Fig. 524. Dolichopus bifractus, caudal aspect. 



Fig. 525. Leptis vertebrata, caudal aspect. 



Fig. 526. Bibiocephala elegantula, caudal aspect. 



Fig. 527. Bibiocephala elegantula, lateral aspect. 



Fig. 528. Dolichopus bifractus, lateral aspect. 



