314 Dr. Frederick A. Dixey on the 
agrees with the latter genus, but in the position of the 
subcostal nervules of the hindwing it retains the condition 
of the former. 
A fresh departure from Colias is headed by the genus 
Meganostoma, which offers a close resemblance to Colias 
in both structure and pattern.* The series S and M, 
fairly distinct in the female of M. philippa, are also 
indicated on the upper surface in the males of some of 
the species. In the males of some other species they 
are fused above, but in all they are distinguishable 
beneath. In the outline of the wings Meganostoma 
shows a close approach to Gonepteryzx, from which genus 
indeed the females of some of the species are hardly to 
be distinguished. 
From Gonepteryx the line passes on to Amynthia and 
Rhodocera. All these’ genera retain many Colias-like 
points, particularly the pinkish patch at the apex of the 
cell on the hindwing undersurface. The males of the two 
latter, like those of Meganostoma and many species of 
Colias, also possess the well-known patches of raised 
scales above the subcostal nervure of the hindwing ; and 
in the same two genera is seen for the first time the 
contrast between areas of flat and raised scales over the 
whole upper surface of the wings which is so conspicuous 
a feature in Catopsilia, Phoebis, and Callidryas. 
Dercas appears to be an Indian offshoot of Gonepteryx. 
A good transition from the latter to the former is 
afforded by D. wallichii, as pointed out by Mr. Wallace, 
Trans, Ent. Soc. Lond., 3rd series, iv., p. 398. 
Kricogonia is probably an analogous derived form in the 
Neotropical Region. 
The HKastern genus Catopsilia forms with the Western 
Callidryas, Aphrissa, Metwra, and Phebis, a group which 
clearly belongs to the present section. Their structure 
and coloration relate them closely to Gonepteryz, though 
in some respects they show signs of a more ancient 
* Mr. Butler (Cist. Entom., iii., p. 46) describes the neuration in 
the forewing of Meganostoma as being like that of Gonepteryz, 
“ excepting that the second subcostal is emitted just before the end 
of the cell.” In some individuals, at any rate, the second subcostal 
is emitted at the end of the cell, and in M. cesonia it may even be 
thrown off after the end of the cell, as often in Colias. This indeed 
is the condition represented in Cist. Entom,, vol. i., pl. i1., fig. 4. 
