246 COMMON BRITISH INSECTS. 



duals. The lower wings are greyish brown, with a 

 dark spot on the disc, and two pale and ill- defined 

 bars. 



The caterpillar is a very quaint and odd-looking 

 creature. The head is comparatively large, and the 

 second and third segments are so small as to form a 

 sort of neck. From the fifth to the ninth segments 

 the back is humped. The colour is rather pretty, 

 being green more or less tinged with yellow, and 

 marked with a very deep purple-brown. There are 

 other markings, but the shape of the larva is so 

 peculiar that minute detail is not needed for its 

 identification. 



This caterpillar may be found on the birch, where 

 it remains until full-fed, an event which takes place 

 somewhere about the end of September. It then 

 descends the tree, and beneath it spins for itself a 

 slight cocoon, which is generally screened from 

 observation by having a fallen leaf fastened to its 

 upper surface. In this exposed situation it changes 

 into a pupa, and there lies until the following June, 

 when it assumes the perfect form. The insect is, and 

 yet is not, a common one. Those entomologists who 

 have not yet learned to look behind the scenes of 

 Nature's theatre reckon the Iron Prominent to be 

 quite a rarity ; while those who have been long 

 accustomed to the practical study of insects and their 

 ways, experience no great difficulty in obtaining either 

 the moth, the pupa, or the caterpillar, and in con- 

 sequence consider the Iron Prominent as rather a 

 plentiful insect. 



