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 

 Atalanta; 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 Qoncptcryx, render them 

 objects on which the eye rests with continual plea- 

 sure ; and the silvery spots and streaks on the under 

 side of the Fritillaries, 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 ova) 

 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 



