SIMULIIDAE OF AFRICA 53 



i?i with well developed spinules as well as hairs ; Rs not forked ; basal section of radius haired ; 

 C«2 with double curvature ; no evident basal cell ; membrane evenly covered with normal 

 microtrichia. Abdomen : Sparsely haired, basal fringe long and pale ; apparently no sclerot- 

 ized tenth tergite ; cerci very large and strongly sclerotized (Text-fig. 314). Hypopygium very 

 similar in form to that found in riificorne-group of subgenus Eusimulium (Text-fig. 311) ; styles 

 tapering and slightly truncate at tips, shorter than coxites, with one apical spinule (Text-fig. 

 313) ; coxite not produced beyond base of style, hairing normal ; ventral plate (Text-fig. 312) 

 large and lamellate, with narrow haired median keel and strongly sclerotized subparallel basal 

 arms ; median sclerite large and elongate, slightly strap-like but each end a little wider than the 

 middle ; parameres long and very slender, each with one very strong large (but not very elong- 

 ate) parameral hook directed outwards and backwards (Text-fig. 311) ; aedeagal membrane 

 strongly spiculate. 



?. Head : Atypical for Simuliiim (Text-figs. 69 & 71), eyes small so that in profile the eye- 

 width is only a little more than the width of the postocular part of the head, in dorsal view eyes 

 wide apart so that frons-width is almost as great as width of one eye and eye-length subequal to 

 length of postocular part of head. Posterior surface of head blackish, frontal and clypeal regions 

 more brownish, frons and posterior parts of head with soft recumbent pale hair, clypeus with 

 long thick pale hair ; frons on either side with some stiffer erect slightly darker hair in addition 

 to pale recumbent hair. Frons with trace of median furrow, especially ventrally. Antenna 

 (Text-fig. 309) similar to male, apparently all pale. Maxillary palps very long, fifth segment 

 slender and three times as long as the fourth segment (Text-fig. 69), sensory vesicle very small 

 and only about one-fifth as long as its segment. Maxillae and mandibles toothed (apparently 

 capable of biting), maxilla with 14-16 strong outer teeth and 10-12 strong inner teeth, mandibles 

 with about 18-20 inner teeth (rather irregular) and about 8 outer teeth. Thorax : Scutum dark 

 brown, trace of blacker broad median band longitudinally, especially noticeable anteriorly, 

 humeral calli paler, scutum evenly covered with pale recumbent scales, some longer pale hair in 

 prescutellar depression. Pleural membrane sparsely pale haired as male, katepisternum and 

 postnotum bare as in male. Legs : Colouring uncertain in dissected spirit material but femora 

 except for tips pale, and mid parts of tibiae and apparently the hind basitarsi paler than the rest. 

 Hind basitarsus not enlarged conspicuously. Tarsal claws with large basal tooth (Text-fig. 316). 

 Wings: as in male. Abdomen: Evenly covered with pale hair. No sternites developed basad 

 of sternite 8. Median depression of sternite 8 strongly sclerotized. Spermatheca without sur- 

 face pattern or internal hairs, spermathecal duct strongly sclerotized for short distance from point 

 of origin from spermatheca. Gonapophyses slightly produced bluntly pointed, darkened and 

 conspicuous (Text-fig. 315), directed backwards. Genital rod normal, lateral arms with well 

 developed anterior process. Paraprocts normal. Cerci normal, subquadrate in lateral view but 

 appearing to be produced to a point posterodorsally because of presence at upper angle of 

 cluster of short stiff close-set setae standing in large-rimmed pores. 



Pupa. Head and thorax : Closely covered dorsally with blackened pointed sharp thorny 

 tubercles (Text-fig. 321), these largest and most strongly aggregated anteromedially on thoracic 

 region, present but least developed on scutellar region ; trichomes simple hair-like, very in- 

 conspicuous. Gill (Text-fig. 322) : With four long strong tapering subequal filaments, very 

 constant in position of branching and directional orientation : two of the filaments form a pair of 

 basal arms of which the dorsal one curves dorsally around the pupal thorax and crosses with its 

 fellow of the opposite side, the ventral one curving and sinuous but not bending strongly towards 

 the opposite side ; between the basal pair the other two filaments arise and diverge very widely 

 with scarcely any trace of common stalk, the dorsal one bending inwards and curling apically but 

 not meeting its fellow of the opposite side, the ventral one bending and becoming sinuous or 

 curling apically but in general direction lying parallel to the ventral filament of the basal pair ; 

 basal part of the upper anterior filament less strongly swollen than other filaments ; all filaments 

 transversely micro-striate along their length (as inset figure to Text-fig. 322). Whole gill very 

 much shorter than pupal body. Abdomen : Aberrant, with many supernumerary hooks and 

 spinous hooklets or hairs as detailed below, abdominal cuticle forming a thin transparent pellicle 



