883 
hippocoonides, clearly proves that in all of them this same oblique 
dark crossbar is equally present, but that in its distal part, outside 
the discoidal cell, it becomes broadened by junction with the nearest 
distal dark marking along the discoidal nervure (Haasr’s Terminal- 
band). In consequence of this junction the bar occupies the proximal 
part of four successive internervural cells (R,, M,, M,, M,: Haasr’s 
VR1+4+2+43-4 4). 
By the occurrence of this crossbar the light-hued middle area of 
the forewing is divided into a smaller apical blotch and a larger 
more or less triangular field along the hinder (inner) margin, the 
latter passing without interruption into the light area which fills the 
proximal part of the hindwing. This division is one of the promi- 
nent features on which the similarity with Danaids depends. But 
it would be quite inadequate to ascribe the occurrence of this bar 
to secondary deviation from the original specific type under the 
influence of natural selection in connection with Protective Mimicry. 
For the same bar occurs in the females of a considerable number 
of nearly allied species, e.g. cynorta, homeyert, jacksoni, ucalegon, 
auriger, adamastor, agamedes, whose males, at least part of them, 
show an uninterrupted chain of light-hued internervural spots, 
which increase in size from before backward, and on the hindwing 
blend to the light middle-field. These spots are separated from 
each other by longitudinal dark striae, caused by the more or less 
pigmented wing-veins. The anterior light spot in the apical field 
of the forewing of P. dardanus is the first of the series, it occupies 
the interspace between the roots of nervus radialis 4 and 5 (radial 
fork) and we get the impression that this position has something 
to do with its more marked persistence, by means of which it 
remains visible, when the other spots are effaced either by light or 
by dark colour-overspreading. Yet this apical spot also is not 
exempt from reduction or obliteration: in some specimens of all 
forms of dardanus, male as well as female, it may be reduced to 
a mere speck, or be wholly absent (comp. the figure of the tropho- 
nius-female on Punnetr’s Pl. VIII). 
Nor is the above-named dark cross-bar restricted to dardanus 
and its nearest relatives, it occurs as well in a number of other 
Papilionids, e.g. hesperus, pelodurus, and others. 
In numerous other cases the tendency towards the formation of 
the cross-bar is equally present, but does not lead to such a con- 
spicuous partition between an anterior and a posterior light area. 
In epiphorbas e.g. the forewing is almost entirely black, with the 
exception of a hooked central green part. The foremost leg of this 
