SIMULIIDAE OF AFRICA 19 



of a widely distributed Prosimuliine fauna common to the Holarctic and 

 Ethiopian areas. 



No really satisfactory larval characters have been found on the limited material 

 available for separating the African subgenera in this stage, and furthermore some 

 species have been described only from the adult. The following key to subgenera 

 is therefore based only on adult and pupal characters. 



Key to the Subgenera of PROSIMULIUM in Africa 



1 Vein Rs forked (Text-fig. 1). Costa with hair-like macrotrichia only. Pupal 



abdomen on each side of segments 4 and 5 with a large pleural plate isolated from 

 terga and sterna by paired longitudinally striate semi-membranous areas. [Moroc- 

 co] PROSIMULIUM Roubaud s. str. (p. 19) 



- Vein Rs not forked, sometimes dilated apically and with vestigial trace of forking. 



Costa with or without spiniform macrotrichia. Pupal abdomen without large pleural 

 plates on segments 4 and 5, only one main longitudinally striate area between the 

 terga and sterna (Text-fig. 42). [Ethiopian Africa] ...... 2 



2 Costa with hair-like macrotrichia only, at most some slightly stouter setae in male. 



Calcipala more or less absent (Text-fig. 22). Pupal gill with 6 or 7 filaments inter- 

 twining apically (Text-figs. 38, 39) . . PROCNEPHIA sgen. n. (p. 21) 



- Costa with well developed spiniform macrotrichia as well as hair-like macrotrichia. 



Calcipala moderately to strongly developed (Text-figs. 23-25). Pupal gill with 

 10-22 filaments (except brincki with 6, but then widely divergent, Text-fig. 41) 



PARACNEPHIA Rubzov (p. 23) 



SYSTEMATIC TREATMENT OF THE SUBGENERA 



In the diagnoses that follow only those characters are shown, in the interests of 

 brevity, that are differential between the subgenera occurring in Africa. All three 

 subgenera in Africa share certain characters that differ from those found in some extra- 

 limital subgenera oiProsimulium, particularly the following that differentiate from the 

 non-African segregates indicated : style with multiple spinules (distinction from 

 Cnephia = Astega, Ectemnia, some Greniera) ; antenna with 11 segments (distinc- 

 tion from some Greniera, also from some extra-limital Prosimulium s. str.) ; more 

 or less complete cocoon present (distinction from Greniera) ; cocoon not stalked 

 (distinction from Ectemnia) ; at least four abdominal segments of the pupa with 

 well developed spine-combs (distinction from Cnesia) ; larval anal sclerite present 

 (distinction from Ectemnia) ; larval abdomen without ventral papillae or transverse 

 ventral fold on last segment (distinction from Greniera, Ectemnia, Stegopterna) ; 

 larval antenna short, not longer than stem of cephalic fan (distinction from 

 Stegopterna, Greniera, Ectemnia). 



Subgenus PROSIMULIUM Roubaud 



Prosimulium Roubaud, 1906 : 521. Type-species : Simulia hirtipes Fries, 1824, by subsequent 



designation of Malloch, 191 4 : 16. 

 H elodon Enderlein 1921 : 199. Type-species : Simulia ferruginea Wahlberg, 1844, by original 



designation. 



