142 



R. W. CROSSKEY 



N/ 



16 



17 



18 



19 



20 



21 



Figs. 16-21. Showing differences between typical Prosimuliini and typical Simuliini. 16 

 and 17, ventral view of mesepisternal sulcus and katepisternum in (16) Prosimuliini and 



(17) Simuliini. 18 and 19, view in profile of katepisternum and mesepisternal sulcus in 



(18) Prosimuliini and (19) Simuliini. 20 and 21, posterior margin of head and cervical 

 sclerites of mature larva in (20) many Prosimuliini and in (21) Simuliini. All figures 

 slightly schematic. 



