160 BRITISH BUTTERFLIES. 



in the male, it is sometimes very indistinct. The under 

 side much resembles that of the female of Alexis, the 

 border of orange spots being even more distinct on the 

 front wing than on the hind one. It will be observed 

 on referring to Plate XIV. that on the under sides of 

 all the butterflies there figured, there is an irregular 

 black spot situated near the front edge of the upper 

 wing and midway in its length this is called the 

 "discoidal spot" It will also be observed that the 

 common Blue (fig. 4) has, on the area of the wing, be- 

 tween the discoidal spot and the root of the wing, two 

 spots, which are absent in this species. This forms a 

 very ready mark of distinction, though it requires a 

 good many words to explain it. 



The caterpillar, which feeds on Erodium Cicutarium, 

 and perhaps on Helianihemum (Eock Cistus), is green, 

 with pale spots on the back, and a brownish line down 

 the middle. 



The butterfly appears in May and June, and again in 

 August, and is common in very many localities in the 

 south, being particularly abundant on the downs of the 

 south coast and the Isle of Wight. 



