Phylogeny of the Pierine. PY A 
and in B. calypso, under surface of both sexes and upper 
surface of female. 
In Appias and OCatophaga a discoidal spot can scarcely 
be said to exist; but in Hiposcritia and Pieris various 
members of the series D are often well marked. H. 
lalage ¢ (Fig. 11) has a conspicuous discoidal spot on 
both surfaces of the forewing, formed by D 2; and on 
the under surface of the hindwing there appears a minute 
representative of D4. In H. pandione, D 1 and 2 com- 
pose a large spot which joins the dark costal band; while 
on the under surface of the hindwing, D 4 is sometimes 
indicated by a paling of the first disco-cellular nervule 
and the immediately surrounding area. In Pieris the 
forewing often shows a conspicuous discoidal spot, formed 
by D 1 and 2 or by D 2 alone; the hindwing as a rule 
possessing only a small dark representative of D 4 on the 
under surface, which in P. buni merely touches the 
second disco-cellular, but in P. pylotis encloses it. 
In Pontia and Huphina (Fig. 8), D in the forewing 
appears generally as a mere darkening of the wing in the 
region of the disco-cellular nervules, more pronounced 
than the darkening of other nervures which is common 
in these genera, but not forming a defimite spot. In the 
hindwing it is much less distinguishable or even absent 
(P. crategi, P. soracta, H. phryne, H. timnatha, etc.). 
In Metaporia agathon (Fig. 7) the same darkening of the 
disco-cellular area occurs, which in M. phryxe takes the 
form of a definite and conspicuous patch. A like condition 
is seen in JN. gcea, and other species of Nepheronia. 
The correspondence in pattern of the genera Delias and 
Prioneris with those just discussed, already referred to on 
p. 267, applies to the present as well as to other features 
in the marking. JDelias, moreover, shows in many 
species that paling of the disco-cellular nervules them- 
selves, and sometimes of the immediately surrounding 
area in the midst of the dark discoidal patch, which we 
have seen to occur in Synchloe and other genera, and 
which in Colias, Ivias, and their allies leads to remarkable 
modifications in the general appearance of the discoidal 
spots (see Delias aganippe, D. descombesi, D. crithoe, 
etc.). In D. belisama ¢, the nervules remain dark, 
though there is a surrounding pale area. 
Nothing special needs to be said about the genera 
Euterpe, Catasticta, Leodonta, and Euchetra. Their 
