Mimetic Attraction. 319 
from the original Pierine form has been reached (1) by 
a shght modification in shape and proportions of that 
area of the pale ground colour included between the 
diagonal bar and the dark inner margin of the forewing, 
and (2) by the appearance of a submarginal series of 
pale spots on both fore and hindwing (fig. 5,7”). Both 
of these changes mark an approximation towards the 
characteristic aspect of the protected Heliconius atthis 
group ; but the final link in the Pierine chain, viz., the 
form represented in fig. 7, which appears to be the female 
of P. locusta or of a closely allied species, brings us 
nearer still. Here the pale area on the apical side of 
the diagonal bar (nm) shows a tendency to be broken up 
into separate spots; and the pale ground colour, which 
in P. viardi 2 is uniformly yellow, in P. locusta 2 only 
retains the yellow tint proximally, the subapical area (7) 
and the submarginal spots (7) having resumed their 
original white. These submarginal spots have also 
diminished in size and become more compact in outline. 
In all these respects a further approach is made towards 
H. atthis, and the whole series from P. phaloe or P. caly- 
donia to P. locusta 9 and H. atthis affords as striking a 
succession of transitional forms as that before traced from 
the same ordinary Pierine types up to Mylothris pyrrha 2 
and Heliconius nwmata.* 
3. The “inachia” line. In this line an early step in 
advance of the usual Pierine pattern is taken by Pieris 
pandosia.t On the hindwing underside of this species 
appears a narrow chestnut-coloured streak in the midst 
of the dark hind-marginal band, running paraliel with 
the hind border of the wing. In P. leptalina, Bates (= 
P. pisonis, Hew.), both surfaces of the forewing show a 
diagonal dark bar as in P. calydonia & and other species ; 
there is also a transverse dark bar crossing the under- 
surface of the hindwing nearly parallel with the costa 
(fig. 2). In P. pandosia, where the distal end only of this 
“ Trans. Ent. Soc. Lond. 1896, pp. 65-70. It should be added 
to the foregoing that P. viurdi 2 itself is probably attracted by 
HI. charitonia, which may perhaps be considered an outlier of the 
H, atthis combination. This is analogous to the attraction of 
another intermediate term in the atthis line, viz., P. demophile 9, 
by the agna group. 
+ Figured by Hewitson, Exot. Butt., “ Pieris,” pl. IL., fig. 14, 
and ibid., pl. VL., fig. 39. 
