386 Aiiiiiih of the Simth African Mnxviim. 



M^ and C'it| 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. 



8. 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, ^i 4 rows of cells at f ; i in front w ing 

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



9. In hind wing pro-ximal side of t at arculus. Origin of C'k, in liind wing 



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

 in front wing free or of 2 (rarely 3) cells 6i-7J Aiiq. (Plate XI, 



fig. 2) 10. 



In hind wing proximal side of t distal to arculus. 



Origin of Cti, in hind wing at anal angle of t. No distinct Msjd. ti in 

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

 wings comparatively narrow ; between A3 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 

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

 distinct vulvar scale ....... Chalcostephia. 



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



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

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

 distinct vulvar scale. In hind wing cells between A^ 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 ^3 and wing's edge of ordinary size, not distinctly 

 disposed in transverse rows Diplacodes. 



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



fig. 3.) Hind lobg 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., moderately developed. In hind wing cells between A^ 



and wing's edge not distinctly disposed in transverse rows, i 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 Ss— 

 Bspl, one row M^-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. 



