Phylogeny of the Pierine. 287 
H. erota) can be distinctly seen to belong to the apex of 
the median interspace as well as to the root of the pre- 
costal.* A similiar orange spot is visible in_ several 
species of Pieris, such as P. buniw and P. thaloe; and 
of Leptophobia, as L. elodia and L. elewsis. In the last- 
named insect again it can generally be made out that 
the orange spot does not belong entirely to the root of 
the precostal space, but is furnished with a constituent 
from the apex of the median interspace as well. ‘This 
double character of the spot is much more evident in 
DL. tovaria; and on referring once more to almost any 
species of Colias, the conviction forces itself strongly 
upon us that in these basal marks in Leptophobia, 
Hesperocharis, and Pieris, and so in Huterpe, Leodonta, 
Catasticta, and consequently even in JDelias and 
Prioneris, we see represented the chief material out of 
which the pink basal patch in Colias, Gonepteryx, Catop- 
silia, and their allies is constructed. It is probable that, 
as above suggested, another element may enter into the 
composition of the basal patch in these genera, namely 
one or more members of the series of yellow streaks; a 
conclusion which seems to be somewhat favoured by the 
condition in Belenois, Herpxiia, and Appias; but the 
two series are distinct enough from one another in such 
genera as Catasticta and Leodonta; and an unnamed 
species of Hesperocharis in the British Museum shows, still 
more plainly than those above mentioned, the co-existence 
of a relic of the basal red in the situation of the pink 
patch in Colias, with a series of yellow streaks in the 
interspaces like those of Catasticta and Belenois. 
Summary.—Witk regard to the whole assemblage of 
red and yellow marks on the underside of the hind- 
wing, the following appear to be the most probable 
conclusions :— 
The yellow precostal streak so commonly seen in 
butterflies of this group, including our common British 
species of Ganoris, as also the pinkish patch at the apex 
* In order to avoid a possible ambiguity, I may here mention 
that I regard the “apices” of the interspaces as pointing towards 
the “base” of the wing. When a precostal nervule is present, I 
speak of an “outer” and “ inner” division of the precostal space, 
the nervule forming the line of demarcation. By the “ raot” of 
the precostal space, I mean the part immediately adjoining the 
body. 
