Figures 57-80 



57-74. Seventh sternites of male genitalia, ventral aspect, all drawn to the 

 same scale from males \vith wingspread of 25-27 mm., except for figures 72-74 

 (72 was 31 mm., 73 was 28 mm., 74 was 21 mm.). The stippled areas near the 

 lower edge of figures 61-71 represent areas which are incompletely sclerotized. 

 This trait may often be found in all populations of incurvum and calijornicum, 

 but is rarely found in other species. 



57. M. dis stria. 



58. M. constrictum constrictum. 



59. M. tigris. 



60. At. americanum. 



61. M. incurvum incurvum. 



62. M. incurvum discoloratum. 



63. M. incurvum aztecum. 



64. M. californicum calijornicum. 



65. M. calijornicum ambisimile. 



66. M. calijornicum recenseo. 



67. M. calijornicum pluvi ale, Seattle, Washington. 



68. M. calijornicum pluviale, Alberta (bog population). 



69. M. calijornicum lutescens, Saskatchewan. 



70. M. calijornicum lutescens, Oklahoma. 



7 1 . M. calijornicum Jr agile. 



72. M. neustrium. 



73. M. castr etuis. 



74. M. Jranconicum. 



75-78. Tibia and first tarsal segment of left foreleg. 



75. Male Af. disstria, showing characteristically shaped epiphysis which is 

 always present. Male AI. neustrium have a similarly shaped epiphysis. 



76. Female M. disstria, showing characteristically shaped epiphysis which 

 is usually present, but may be reduced or absent. 



77. Male Ai. incurvum incurvum, showing an unusually large epiphysis for 

 this species. It may be smaller or even absent. 



78. Male Ai. americanum, showing the normal epiphysis. 



79-80. Diagrammatic representation of the location of the pits used in 

 sexing larvae, showing ventral aspect of terminal abdominal segments. 



79. Male. 



80. Female. 



217 

 279-2S0— 6S 16 



