I. HAIR-TUFTS, ETC., OF MALE LEPIDOPTERA 609 
hind-wing is similarly folded, but the second fold of its basal half is turned 
outwards, and not inwards. The inner surface of the first fold, and that 
part of the wing hidden by it is brownish white, somewhat iridescent, and 
densely covered with a pelt of the same colour. 
In the fifth division, which, together with their nearest allies, Felder 
calls American Ornithoptera / the formation of the hind-wing in the male 
is similar to that of the second division ; it is deeply emarginate at the 
anal angle, the greatly developed inner margin is inwardly folded, the 
basal part again outwardly, the hidden surface covered with brownish 
white scales, and, as far as the submedian, densely clothed with a wonderful 
silky white pelt. 
Hesperidae. 
In several genera the anterior margin of the fore-wings is folded 
(“ costal fold,” Herrich-Schaeffer), and the enclosed part thickly covered 
with pale down. In other species (.Ismene oedipoded ), the male has a large 
velvety patch near the base of the fore-wing ; in others ( Hesperilla ), the 
males are characterized by a “ scale blister ” [Schuppenwulst] of the fore¬ 
wings, while in Gaecina the inner margin of the fore-wing is produced 
near the base, is smooth beneath and covers a tuft of hair on the 
hind-wing. 
So far for the diurnal Lepidoptera. That such structures are not 
wanting in the Heterocera is shown by Galesia comosa , G-uen., whose male 
has a large hair-tuft on the upper side of the fore-wings. 
However incomplete the above review may be, it will suffice to prove 
the wide distribution of analogous structures among diurnal Lepidoptera, 
as well as their astonishing variety. What an immense difference between 
the incredibly thick, snow-white, silky covering of hairs on the broad 
folded part of the hind-wing of Papilio nephalion, the large chalky patch 
on the hind-wing of Catlidrycis trite , covered by a long mane, and hidden 
under the inner margin of the fore-wing, the delicate hairy tuft in the 
centre of the hind-wing of Opsiphanes cassiae, and the coal-black spot in 
the middle of the Morpho -like blue of the fore-wing of Theda / And yet 
among all these differences certain common features are to be found. 
Common to most of these structures is the fact that they are not usually 
exposed, but enclosed, it may be, and this is the most usual arrangement, 
between the inner margin of the fore, and the costal margin of the hind- 
wings, or between the inner margin of the hind-wings and the abdomen, 
in a folded part of the anterior margin of the fore, or the inner margin 
of the hind-wings, or finally in special furrows, slits or pockets. Hot 
infrequently the tuft or spot lies opposite to a bare patch or to a similar 
1 This designation is justified by the pupa of our P. nephalion, which lives on 
Aristoloehia , and is entirely similar to that of Ornithoptera heliacon .—F.M. 
2 R 
