210 D. S. FLETCHER 



Key to Species 



i Apex of ventral plate of gnathus deeply excavate to approximately one-third 



or more of total depth of plate ........ 2 



- Ventral plate of gnathus not so formed ....... 3 



2 (1) Ventral plate of gnathus subequal in width to that of uncus; apical margin 



excavate in U-shaped form to one-third of depth of plate, greatest width 



of excavation one-half width of plate. .... bilobata (p. 214) 



- Ventral plate of gnathus broader than uncus, broadly excavate to three-fifths 



of depth of plate, greatest width of excavation three-fourths width of plate 



clavigera (p. 213) 



3 (1) Apical margin of ventral plate of gnathus arcuate and scobinate, broader 



than base ............ 4 



- Ventral plate of gnathus of even width or tapered, apical margin not broader 



than base ............ 5 



4 (3) Uncus trapezoid, truncate apex narrower than base. Apex of dorsal margin 



of valve broad and multi-spined, curved towards uncus (Text-fig. 347). 

 Distribution: Principe I. ..... . principis (p. 211) 



Uncus almost square, truncate apex equal in width to base. Apex of dorsal 

 margin of valve tapered to single spine, curved towards uncus (Text-fig. 

 349). Distribution: Fernando Po, W. African mainland platycephala (p. 211) 



5 (3) Valve: apex of dorsal margin turned abruptly through 90 degrees towards 



ventral margin; ventral margin produced beyond level of apex of dorsal 

 margin, strongly sclerotized, spatulate in form and scobinate (Text-fig. 

 364) • rupta (p. 217) 



- Valve not so formed .......... 6 



6 (5) Apex of valve bifurcate .......... 7 



- Apex of valve curved through 120-90 degrees towards uncus and tapered 



apicad, surface smooth or scobinate ....... 9 



7 (6) Aedeagus with acicular projection at one-third, projection one and one-half 



times as long as greatest width of aedeagus . . . onycha (p. 216) 



- Aedeagus not so formed ......... 8 



8 (7) Uncus evenly tapered to rounded apex. Apex of valve deeply bifurcate; 



ventral and dorsal arms longer than width of valve at point of cleavage 



merga (p. 218) 



- Uncus truncate at apex; a short, beak-like point projects ventrad from 



mid-apical margin. Valve shallowly bifurcate; extended angular apices of 

 ventral and dorsal margins shorter than width of valve at point of cleavage 



bicuspida (p. 214) 



9 (6) Apex of uncus tricuspid ...... tricuspida (p. 212) 



- Uncus not so formed .......... 10 



10 (9) Apex of uncus rounded. Apical fourth of fulcrum dilate, dorsal surface with 



two parallel, coarsely serrate ridges .... subincoloris (p. 220) 



- Apices of uncus and fulcrum not so formed . . . . . . 11 



n (10) Uncus almost square in shape, with a short, ventrally inclined projection 



from mid-apical margin. Ventral plate of gnathus very strongly sclerotized, 

 apex shallowly bilobate. Apex of fulcrum broadened, shallowly bifurcate 

 and coarsely scobinate ....... xyele (p. 221) 



- Uncus, gnathus and fulcrum not so formed . . . . . .12 



12 (11) Dorsal margin of valve excavate just below apex, which is short and smoothly 



acicular ........ consummata (p. 2; 6) 



- Valve not so formed; tapered apex coarsely scobinate . . . . 13 



13 (12) Fulcrum broadened medially, then tapered apicad. Uncus trapezoid, apical 



