386 Annals of tlte ti<tf/i African Museum. 



J/ 4 and C'(!, in front wing approximately parallel at least to a level of 

 nodus : discoidal field between parallel veins to wing's edge, or con- 

 tracted, or widened only for a short distance in a level far distal to 

 nodus. (Plate XI, figs. 4, 5) .... ... 13. 



S. In discoidal field of front wing two rows of cells at i ; t in front wing free. 

 (Plate XI, fig. 2) . . . . 9. 



In discoidal field of front wing, 3-4 rows of cells at t ; t in front wino- 

 crossed (Plate X, fig. 11, and Plate XI, figs. 1, 3) . . . .11 



9. In hind wing proximal side of / at arculus. Origin of Cir, in hind wino- 

 separate from anal angle of t. Mspl distinct, at least in front wing, ti 

 in front wing free or of 2 (rarely 3) cells 6.V -7- Anq. (Plate XI, 

 % 2) . .... 10. 



In hind wing proximal side of t distal to arculus. 



Origin of C'tt, in hind wing at anal angle of t. No distinct Mspl. ti in 

 front wing of 3 cells 8-10i Anq. One row of cells Rs-RspL Hind 

 wings comparatively narrow ; between A 3 and wing's edge 2 rows of 

 cells in middle of field. Pterostigma light coloured in central, dark in 

 peripheral parts. Hind lobe of prothorax moderate. Abdomen short, 

 depressed in male, cylindrical in female. In male a large bifid process 

 011 first ventral plate ; in female margins of eighth segment folded ; no 

 distinct vulvar scale . . .... Chalcostephia. 



It). Basal segments of abdomen (1-4 or 5) much widened, vesiculate, their 

 joints soldered; terminal segments thin, cylindrical. Hind lobe of pro- 

 thorax large. Female with margins of segment 8 folded, small but 

 distinct vulvar scale. In hind wing cells between A 3 and wing's edge 

 very large, disposed in transverse rows. (Plate XI, fig. 2) . Acisoma. 

 Basal segments of abdomen of ordinary form, terminal segments slightly 

 fusiform in male, cylindrical in female. Hind lobe of prothorax mode- 

 rate. Female with genital segments as in preceding genus. In hind 

 wing cells between A 3 and wing's edge of ordinary size, not distinctly 

 disposed in transverse rows ....... Diplacodes. 



11. Pterostigma unicolorous. No black stripe in subcostal field. (Plate XI, 



fig. 3.) Hind lobe of prothorax small. Abdomen depressed, compara- 

 tively broad ........ 12. 



Pterostigma two-coloured, white in proximal, black in distal half. Male 

 with black stripe in subcostal space of front wings. (Plate X, fig. 11.) 

 Female with tips of wings blackish brown. (Plate XI, fig. 1.) Hind 

 lobe of prothorax moderate. Abdomen narrow, slightly fusiform in 

 male, cylindrical in female. Margins of eighth segment in female folded, 

 vulvar scale rather large Hemistigma. 



12. Double curve of M. 2 moderately developed. In hind wing cells between A$ 



and wing's edge not distinctly disposed in transverse rows, t in front 

 wing with one cross-vein, in hind wing predominantly free. Three rows 

 of cells in discoidal field of front wings, predominantly one row Rs- 

 Rspl, one row M 4 -Mspl. (Plate XI, fig. 3.) Angles of frons not 

 projecting. Females with margins of eighth segment folded, vulvar scale 

 erect, large. On anterior surface of frons two distinct triangular 

 flattened spaces Crocothemis. 



