io8 Chionaspis. 



(f) Female scale opaque white ; concealed within glandular pits on the 

 leaf 6. scrobicularum. 



II. Median lobes separate, more or less divergent. 



A. Median lobes prominent. 

 {a) One pair of lateral lobes. 



(rt) Female scale white, dilated behind 7. gravunis. 



{j3) Female scale white, narrow and very elongated not dilated 



behind 8. elongata. 



(y) Female scale white ; secretionary area very small. 



9. arundinarice. 

 (S) Female scale minute ; glassy ; colourless ; transparent. 



10. viinttta. 

 {b) Two pairs of lateral lobes. 



(«) Circumgenital glands absent. 



(i) Female scale yellowish, transparent. Adult insect black ; 

 pygidium, in final stage, completely retracted. 



1 1 . pei'miitans. 

 (/3) Circumgenital glands in five groups. 



(i) Female scale white. Lobes broad but not very prominent, 

 scarcely projecting beyond margin 12. herbce. 



(ii) Female scale white, or coloured by particles of the cuticle of 

 the plant. Lobes conical and prominent. Squames large and 

 numerous 13. polygoni. 



(iii) Female scale brownish fulvous ; with median ridge. Lobes 

 small but prominent, squarely dilated at extremity. Dorsal 

 pores irregularly disposed 14. acuminata. 



(iv) Female scale colourless ; completely covered with the 

 stellate hairs of the leaf. Lobes large and prominent, squarely 

 dilated at extremity 15. elaagni. 



(v) Female scale whitish ; thin and semi-transparent. Lobes 

 conical ; small, but prominent 16. vitis. 



(vi) Female scale white ; thin and semi-transparent. Lobes 

 bluntly conical, rather inconspicuous and sunk into margin. 



17. hedyotidis. 



B. Median lobes sunk in a conspicuous cleft. 



{a) Circumgenital glands in five groups. Female scale white or whitish. 



(a) Anal below genital aperture 18. litzecB. 



(jS) Anal above genital aperture. 



(i) Median lobes small. Two pairs of lateral lobes. 



19. varicosa. 

 (ii) Median lobes small. One pair of lateral lobes. 



20. dilatata. 

 (iii) Median lobes very large 21. megaloba, 



(b) Circumgenital glands absent. Female scale yellow. 



22. flava. 



III. Median lobes large and prominent ; separate but not divergent. A pair of 

 conspicuous club-shaped organs above the lobes. No circumgenital glands, 



23. biclavis. 



