154 



R. W. CROSSKEY 



120 



121 



122 



123 



124 



125 



126 



127 



128 



129 



130 



131 



132 



133 



134 



135 



136 



137 



138 



139 



Figs. 120-139. Showing form of ventral plate of <$ genitalia in profile in subgenera and 

 species-groups of African Simulium. 120 and 121, Pomeroyellum, alcocki-group . 122, 

 Pomeroyellum, kenyae-group. 123, Eusimulium, loutetense-gxoxip. 124, Eusimulium, 

 aureum-group. 125, Eusimulium, ruficorne-gr oup. 126, Meilloniellum. 127, Lewis- 

 ellum. 128, Phoretomyia. 129, Xeno simulium. 130, Byssodon. 131, Freemanellum. 

 132, Anasolen. 133, Metomphalus, medusaeforme-group. 134, Metomphalus, bovis-group. 

 135, Metomphalus, albivirgulatum-gx oup. 136 and 137, Edwardsellum. 138, Tetisimul- 

 ium. 139, Odagmia. 



