268 Dr. Frederick A. Dixey on the 
and other cases, always traversed by the peripheral 
portion of a nervule or nervure. ‘This fact is well 
exemplified by M. agathina, M. poppea, and several 
other species of Mylothris (Fig. 12). 
The invasion of white, which is already considerable in 
D. eucharis 2, becomes still more predominant in the 
male of the same insect, where, however, the original 
ground-colour still persists, not only in the series S and 
M, but also in the form of the dark streaks accompanying 
the nervures and nervules, a feature which we have seen 
_ to be common in many other genera, especially Pontia, 
Huphina, Metaporia, and Nepheronia. 
Without leaving the genus Delias we can find several 
examples where the intrusive white has ousted the whole 
of the original ground-colour, except at the margins and 
apex. This is the case for instance in D. descombesvid, 
D. agostina &, D. coeneus $,and D. momea. In most of 
these species the dark marginal area is plainly composed 
of S and M inamore or less complete state of fusion, 
and it is noticeable here as elsewhere that the female 
almost invariably retains a larger proportion of the 
original ground-colour than the male. 
Many species of Belenois resemble the last mentioned 
species of Delias in the tendency towards fusion of the 
marginal and submarginal series. LD. peristhene (Vig. 14) 
is exceedingly like D. momea in this respect, and in B. 
teutonia 2? and B. coronea the fusion is still more com- 
plete. But in very many species of Belenois and 
Pinacopteryx, S and M are plainly distinguishable from 
one another; and in some, as in B. calypso (as also in 
Pinacopteryx capricornus), the resolution of both into a row 
of dots is complete. The formation of a series of rings 
along the margin of the hindwing (as in Synchloe calli- 
dice 2, S. protodice 2, etc.), by the union of the horns 
of the crescents or chevrons belonging to series 8 with 
the spots of series M, is a noticeable feature on both 
surfaces of many specimens of B. mesentina $ (see 
Fig, 138); and the identity of the whole arrangement of 
the submarginal and marginal series in Belenois with that 
in Synchloe becomes perfectly evident on a comparison of 
B. mesentina with S. johnstonw or 8. hellica. 
In Appias the two series when present are not sharply 
marked off from one another. In some species, however, 
S has almost or quite disappeared, and M may persist 
