Explanation of Plate D. 



Plume-scales of Pierinae. 



Fig. 1. Bklknots thysa — •/, fimbriae; /, lamina; s, footstalk 

 d, disc. 



2. euchloe cardamines. 



3. Mylothris agathina. 



4. Ganoris rapae. 



In these figures, magnified about 480 diameters, an attempt is 

 made to represent in each case the characteristic sculpturing of 

 the chitinous scale. 



Noticeable points in Belenois thysa are (1) the bend in the foot- 

 stalk, which as it leaves the lamina is directed first upwards and 

 then downwards, and (2) the large comparative size and opacity of 

 the accessory disc. 



In Euchloe cardamines may be observed (1) the comparative 

 bluntuess of the apex, (2) the longitudinal ribbing of the lamina in 

 relation with the fimbriae, and (3) the small size of the accessory 

 disc. 



The figure of the scale of Mylothris agathina shows the chitinous 

 network of the lamina, and other remarkable features characteristic 

 of the African Mylothris. 



In Ganoris rapae should be noted the elegant contour of the scale, 

 its elaborate and regular sculpturing, and the opacity arising from 

 the accumulation ot small granules near the apex. 



