SIMULIIDAE OF AFRICA 



157 



neck 



164 



167 



16S 



Figs. 164-173. Form of cocoon and pupal abdomen in African Simulium. 164 and 165, 

 dorsal view of (164) simple slipper-shaped cocoon, and of (165) shoe-shaped cocoon with 

 neck. 1 66, outline of simple cocoon in profile. 167, outline of shoe-shaped cocoon in 

 profile. 168-173, showing arrangement of hooks dorsally (168-170) and ventrally (171- 

 173) on pupal abdomen in : (168 and 171) great majority of forms ; (169-173) in some 

 phoretic forms occurring on mayflies. The spine-combs shown on the dorsum of seg- 

 ments 6-8 in figure 168 are absent in many forms. 



