56 
INTRODUCTION. 
of blue. What can exceed the fine pencilling and 
harmonious tinting on the under surface of the wings 
of Cynthia Cardui, Limenitis Camilla, and Vanessa 
Atalanla; or the richness of the eye-like spots that 
decorate the wings of the Peacock Butterfly, and nu- 
merous other species ? The warm and beautiful shades 
of yellow in Colias and Gonepteryx, render them 
objects on which the eye rests with continual plea- 
sure ; and the silvery spots and streaks on the under 
side of the Frilillaries, form a fine relief, by their 
brilliant metallic lustre, to the uniform and compa- 
ratively duller tints of black and brown which predo- 
minate among that tribe. 
The mode of painting employed to produce these 
rich tints, may not improperly be called a kind of 
natural mosaic, for the colours invariably reside in 
the scales, which form a dense covering over the 
whole surface. These scales are usually of an oval 
or elongated form, and truncated at the tip, where 
they are occasionally divided into teeth ; but some- 
times they are conical, linear, or triangular. (A 
considerable number of the most remarkable forms 
which they exhibit, are represented at the top of 
Plate I. fig. 1. Fig. 2, shews the form they some- 
times assume in the fringe which surrounds the wing.) 
They are fixed in the wing by means of a narrow 
pedicle, and are most commonly disposed in trans- 
verse rows, placed close together, and overlapping 
each other like the tiles of a roof. In some instan- 
ces, they are placed without any regular order, and 
in certain cases there appear to be two lyers of 
