102 ILLINOIS BIOLOGICAL MONOGRAPHS [272 



EXPLANATION OF PLATE 

 Labium and other Parts 



Fig. 459. Heteroneura flaviscta, caudal aspect. 



Fig. 460. Heteroneura flaviseta, mesal aspect. 



Fig. 461. Loxocera pectoralis, caudal aspect. 



Fig. 462. Loxocera pectoralis, mesal aspect. 



Fig. 463. Tetanocera plumosa, caudal aspect. 



Fig. 464. Tetanocera plumosa, mesal aspect. 



Fig. 465. Musca domestica, dorsal aspect of glossae. 



Fig. 466. Musca domestica, caudal aspect. 



Fig. 467. Musca domestica, mesal aspect. 



Fig. 468. Archytas analis, caudal aspect. 



Fig. 469. Archytas analis, mesal aspect. 



Fig. 470. Scatophaga furcata, caudal aspect of mediproboscis. 



Fig. 471. Scatophaga furcata, ventral aspect of distiproboscis. 



Fig. 472. Scatophaga furcata, mesal aspect. 



Fig. 473. Thelaira leucozona, caudal aspect. 



Fig. 474. Thelaira leucozona, mesal aspect. 



Fig. 475. Hydrotaea dentipes, caudal aspect. 



Fig. 476. Hydrotaea dentipes, mesal aspect. 



Fig. 477. Sarcophaga haemorrhoidalis, caudal aspect. 



Fig. 478. Sarcophaga haemorrhoidalis, mesal aspect. 



Fig. 479. Stomoxys cat citrons, distal end, lateral aspect. 



Fig. 480. Stomoxys calcitrans, distal end, mesal aspect. 



Fig. 481. Lis pa nasoni, distal end, mesal aspect. 



Fig. 482. Bombylius major, cross-section thru pseudotrachea. (After 



Dimmock.) 



Fig. 483. Oclithcra mantis, cross-section thru pseudotrachea. 



Fig. 484. Musca (Calliphora) vomit oria, cross-section thru pseudotrachea 



(After Dimmock.) 



Fig. 485. Musca (Calliphora) vomitoria, an enlarged pseudotrachea. (After 



Dimmock.) 



Fig. 486. Oncodes costatus, entire mouth-parts, caudal aspect. 



Fig. 487. Oncodes costatus, entire mouth-parts, lateral aspect. 



Fig. 488. Olfersia ardeae, distal end, lateral aspect. 



Fig. 489. Simulium venustum, cephalic aspect of the labrum. 



Fig. 490. Gastrophilus equi, entire mouth-parts, caudal aspect. 



Fig. 491. Gastrophilus equi, sagittal section thru mouth-parts. 



Fig. 492. Gastrophilus equi, entire mouth-parts, cephalic aspect. 



