Explanation of Plate F. 



Plume-scales of Pierinae. 



Fig. I. Belenois gidica. Fig. 8. Mylothris lypera. 



2. Pereute swainsonii. 9. Leptophobia aripa. 



3. Euterpe tereas. 10. Nychitona dione. 



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



5. Delias pandemia. wing). 



6. PiERis phaloe. 12. Tachyris placidia (hind- 



7. „ pylotis. wing). 



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

 ovitline, 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 diff"erence in disc between Delias and 

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

 section of ^^ Pieris" and the so-called American M>jlnthris ; 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 Lejitophobia ; 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 respectiveh' in T. placidia. 



