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Genus IDEA. 
The above genus is of very limited extent, compre- 
hending only four species. They are, however, 
somewhat remarkable insects, both on account of 
their size, and the manner in which their colours 
are distributed. The wings are slightly transparent 
and of a greyish white, with black stripes running 
along all the nervures, and occasionally forming 
blotches on the surface. The nearest approach to 
this mode of colouring among other tribes is pre- 
sented by certain species of Euploea, and particu- 
larly by Pap. dissimilis, which on this account has 
been termed the Idea-likeness butterfly. The most 
conspicuous of its generic characters are the slender- 
ness of the antenna;, which are so slightly thickened 
towards the apex as to appear nearly filiform, and 
the elongated oval form of the wings : in other 
respects Idea nearly conforms to the genera with 
which it is associated. The palpi have the terminal 
joint minute and conical, the second long and thick- 
est in the middle, the radical one not half its length. 
The tarsal division of the anterior legs is dilated, 
and furnished with two or three unequal spines. 
