80 



ILLIXOIS BIOLOGICAL MONOGRAPHS 



[2sa 



EXPLANATION OF PLATE 



Lateral Aspect of the Head showing the Tentorium 



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55. Bibioccphala clcgantiila, female. 



56. Bibioccphala degantula, male. 



57. Rhyphus punctatus. 



58. Trichoccra biuiacula. 



59. PsoropJiora ciliata, female. 



60. Stratiomyia apicitia, male. 



61. Mycetobia diver gens. 



62. Exoprosopa fascia ta, eye removed. 



63. Dixa clavata. 



64. Em pis claiisa, female. 



65. Plaiypcza vclutina. 



66. Psychoda albipcniiis. 



67. Eristalis tcua.r, female, eye removed. 



68. Dolichopus bifractus. eye removed. 



69. Loxoccra pcctoralis. 



70. Rhabdophaga strobiloides. 



71. Sapromyca vulgaris. 



72. Drosophila ampclnphila. 



72)- Psilocephala haeiuorrhoidalis, female. 



74. Aphiochaeta agarici. 



75. Euaresta aequalis. 



76. Heteroneura ftaviseta. 



77. Lonchoptera lutea. 



78. Tipula bicornis. 



79. Chyroiiiya concolor. 



