Phylogeny of the Pierinee. 250 
In certain genera (Hronia, Huchloe, etc.), the presence 
of a fifth subcostal nervule eves rise to an additional 
interspace in the forewing; this, however, causes no 
difficulty, inasmuch as the extra interspace so formed is 
never occupied by a distinct spot. If necessary, the 
additional subcostal interspace may be referred to as 
5a; by which plan we shall avoid throwing the number- 
ing out of correspondence with that adopted in the other 
genera (see Fig. 23). In those genera (Pereute, Delias, 
etc.) which possess only three subcostal nervules in the 
forewing, I shall for convenience consider S 4 as 
absent. 
Having identified the series S in the species named, 
we shall find no difficulty with the remaining members of 
the genera Synchloe and Tatochila, all of which possess it 
in a condition of greater or less development. In all these 
cases, if the sexes differ, the female invariably presents 
the series in greater completeness ; though such of the 
spots as are present in the male are sometimes more 
distinct. Thus in SW. hellica 2, the whole range occurs 
with the exception of S 9 (this being also the spot 
which is regularly small or absent in N. callidice and 
S. daplidice 2), and the spots show a great tendency to 
fuse into a submarginal band, especially towards the 
costa of the forewing. In the male, however, all are 
absent from the hindwing, and S 9—11 also from the 
forewing; 8 8 is distinct; S 7 hardly visible; and S 2—5 
are fused into a single spot which is more distinct than the 
corresponding patch in the female. 
The same submarginal series can be traced with equal 
certainty in the genus Belenois. Here again the series 
is as a rule more complete in the females, while the 
individual spots are more distinct in the males. This can 
be well seen for example in B. mesentina (Fig. 15), where 
the males show a submarginal band on the forewing which 
can without difficulty be resolved into a series of five spots, 
representing S 2—3,5,6, 7and 8. On the upper surface 
of the females the spots show a greater tendency to fuse 
with one another, and with the dark area of the apex and 
hindmargin ; they are nevertheless in most specimens 
recognizable on the upper surface, and nearly always 
fairly distinct beneath. Much the same is the case with 
the submarginal series on the hindwing; this is constantly 
present in a distinct form on the under surface of both 
