158 BRITISH BUTTERFLIES. 



This very pretty little insect is the blue butterfly one 

 sees everywhere, abounding in meadows, on heaths and 

 downs, and not at all confined to chalky soils, like 

 some other "blues." 



The caterpillar is green, with darker stripe on the 

 back, and white spots on each side. It feeds on Bird's- 

 foot Trefoil and other leguminous plants. 



The butterfly is to be found almost constantly from 

 the end of May to the end of September, being double- 

 brooded. 



THE SILVEK-STUDDED BLUE. 



(Polyommatus JEgon.} (Plate XIV. fig. 5, male ; 

 5 a, Female.) 



Colouring : Upper side, male, purplish blue (rather 

 deeper than that of Alexis), with a rather broad black 

 margin. Female, dark brown, sometimes slightly tinged 

 with blue, and bordered on the hind wings with dull 

 orange spots ; but these are often absent. 



Fringe white, not barred with black. Under side, 

 near the margin of the hind wings, and between that 

 and the orange border spots, are several metallic spots, 

 of a bluish tint, whence the insect has its name of 

 " Silver-studded." 



