1 86 THE BOOK OF BRITISH BUTTERFLIES. 



be sought for on heaths, downs, and commons, and 

 in such situations seems to be fairly well distributed 

 throughout England. It is by no means confined to 

 chalk, the sandy downs of Surrey, indeed, being amongst 

 its favourite haunts. 



The eggs are laid in the summer on the Bird's-foot 

 (Ornithopus perpusillus\ and hatch in the following spring. 

 The larvae, which have also been seen feeding on the 

 common Furze (Ulex europ<zus\ are full-fed about the 

 middle or end of June, when the pupae may be found. 

 The butterflies appear the next month and continue 

 into August. 



The colour of the larva (Fig. 205), which is of the 

 shape common to the genus, is bright yellowish-green. 

 Along the back is a dark stripe with whitish edges ; near 

 the head this line assumes the form of three spots, and 

 behind these it bears four white dots. On each side is 

 a subdorsal yellowish line bordered by rather dark green 

 ones. There is a whitish line on the lateral dilatation, 

 and above it a series of indistinct oblique yellowish 

 streaks. The twelfth segment bears two rather conspicuous 

 warts, and the body is covered with fine, short hairs. 

 Its length is not much over iin. 



The pupa, which is less than ^in. in length, has the 

 larval skin attached to the anal extremity, and does not 

 seem to be very well adapted for suspension. It is 

 unangled and smooth, but not shining. The abdomen 

 is swollen, and the wing-cases are long and prominent. 

 It is dull green in colour, with a line of dark marks 

 shaped like arrow-heads down the back. 



The wings of the imago (Figs. 206 to 208) are. long 

 and slender, and the margins are entire, those of the 

 fore-wings being slightly convex. The fringe is white. 

 The colour of the upper surface of the male (Fig. 207) 



