the wings being of golden green or blue. The genus _Urania_ has
this radiance still more conspicuous; while the inferior surface of some
of the _Theclae_, as _T. imperialis_, _T. Actaeon_, _T. Endymion_, &c., is
covered with the most rich and varied metallic hues, as if powdered
with gold, copper, and silver filings. Some Butterflies, as several of
our native _Fritillaries_, and more vividly an American species,
(_Argynnis passiflorae_,) one from New Zealand, (_Argyrophenga
antipodum_,) and the beautiful _Paphia Clytemnestra_, have spots of
burnished silver on their inferior surface; and several of our own
moths, as the genus _Plusia_, are so spotted on the upper surface.
Others display a lustre between that of silver and that of pearl, as
several species of _Charaxes_ on one, and the magnificent _Morpho
Laertes_ on both surfaces. But of this sort of beauty, perhaps nothing
can excel the gemmeous green, changing to azure, of _Papilio Ulysses_,
or that of _Apatura (?) laurentia_; or, above all, of some of the great
Brazilian _Morphos_. The blaze of silvery azure that flashes from _M.
Adonis_, _M. Cytheris_, and _M. Menelaus_, is indescribable; the eyes
are pained as they gaze upon it; yet there is said to be an unnamed
species from the emerald mountains of Bogota, of which a single specimen
is in a private cabinet in London, which is far more lustrous than
these.

The change from one hue to another produced by the play of light in
altering the angle of its reflection, has always been much admired; and
this occurs in great perfection, and with much diversity, in the lovely
insects of the _Lepidopterous_ order.

Some of the genus _Haetera_, (as _H. piera_, and _H. esmeralda_,) and
many of the _Heliconiadae_, as _Hymenitis diaphana_, &c., have the wings
nearly or quite destitute of the ordinary scaly clothing, presenting
only a transparent membrane of great delicacy; over which the light
plays with a beautiful iridescence. _Papilio Arcturus_ and some allied
species, are of a golden-green, changing to blue, or to glowing purple.
Very many of the _Nymphalidae_ are distinguished for a flush of
surpassing richness, that in one particular light gleams over the
surface. Our own _Apatura Iris_, commonly known as the purple emperor,
is a native example of this beauty, and still more _A. namoura_; but
especially the species of the genus _Thaumantis_, as well as _Morpho
Martia_, and _M. Automedon_. _Diadema bolina_ also displays a