Explanation of Plate F. 



Plume-scales op Pierinae. 



Fig. 1. Belenois gidica. Fig. 8. Mylothris lypera. 



2. Pereute swainsonil 9. Lbptophobia aripa. 



3. Euterpe tereas. 10. Nychitona dione. 



4. Catasticta plisa. 11. Tachyris placidia (fore- 



5. Delias pandemia. wing). 



6. PlERIS PHALOE. 12. TaCHYRIS PLACIDIA (llind- 



7. ,, PYLOTis. wing). 



The figures in this, as in the preceding plate, are drawn only in 

 outline, and are magnified about 260 diameters. 



They illustrate the remarkable scent-scale, unique in its genus, of 

 Belenois gidica ; the extreme breadth in proportion to length found 

 in the scent-scales of many species of Catasticta ; the great difference 

 in respect of these structures between the genera Pereute and Euterpe ; 

 the resemblance in lamina and difference in disc between Delias and 

 a section of " Pieris " or Perrhybris ; the likeness between another 

 section of ^^ Pieris" and the so-called American Mylothris ; the 

 wide difference between the latter and the African species related 

 to M. agathina and M. chloris (compare Plate D, fig. 3). Other 

 points to be noted are the minute disc of Leptophobia ; the trowel- 

 like outline of Nychitona ; the relatively enormous accessory disc 

 characteristic of the scales from the hindwing in species of the 

 celestina group of Tachyris, and the other remarkable differences 

 between scales from fore- and hind-wing respectively in T. placidia. 



