KEY TO THE GEITO3 BOOPHILUS * 



1. With caudal appendsige 2 



Without caudal appendage. Hypostome 

 dentition U/U (see Note below). Palpal 

 basal segment without ventral bristle- 

 bearing protuberance on inner margin. 



Adanal shields without posterior spur B. ANNULATUS 



F igure s~10^ and I05 



2. Hypostome dentition 3/3 (rarely 3.5/ 

 3.5). Palpal basal segment with 

 ventral, inner bristle- bearing pro- 

 tuberance. Adanal shields with long, 

 narrow internal spur usually extending 



beyond body margin B. DSCOLCRATUS 



Figures 108 and I09 



Hypostome /^/U. Palpal basal segment 

 without ventral, inner bristle- bearing 

 protuberajace . Adanal shields with 

 inner margin hardly extended if at all 



and not reaching body margin B. MIGROPLUS ** 



Figures 112 and II3 



^Preserved specimens must be entirely free of surface sheen from 

 liquid preservatives before identification can be attempted. The 

 caudal appendage of d" 3. de color atus is very variable in size and 

 the petlpal basal bristle-bearing protuberance of either sex can be 

 seen only when the mouthparts are absolutely clean; the bristles 

 are frequently broken off. Turning the specimen at an angle to 

 the light may be necessary to see this character as well as the 

 groove of coxa I. 



**B. micro plus does not occxir in the Sudan but there is some likeli- 

 hood that it may reach the Sudan within a few years. The inclusion 

 of B. microplus in this key makes it serviceable for all known 

 species, according to contemporary concepts of the genus. 



- 295 - 



