54 BRITISH BUTTERFLIES. 



these are questions that still remain to be answered. 

 There is, I believe, no foundation for the opinion some- 

 times held by entomologists, that this species prevails at 

 regular periods, such as once in fonr, or once in seven 

 years. In fact, for the last two or three years its per- 

 manent residence and appearance among us seems to be 

 established, while, at the same time, its northward 

 range has been greatly extended, a considerable number 

 having been taken even in Scotland its existence in 

 that country having been previously quite unheard of. 



The environs of London, especially on the south side, 

 have been abundantly visited by this charming insect ; 

 but its tastes have a decidedly maritime tendency, and 

 we find it has a marked preference for the South Coast ; 

 abounding, again, more especially towards the eastern 

 end. Its favourite resorts are clover and lucerne fields, 

 though dry flowery meadows, open downs, and the sides 

 of railway-banks are also the scenes of its lively flight 

 for Edusa has indeed a lively flight, and his pursuer 

 has need of the "seven-league boots," with the hand of 

 Mercury, to insure success in the fair open race, if that 

 can be called a fair race at all, between a heavy biped, 

 struggling and perspiring about a slippery hill-side, such 

 as Edusa loves, and a winged spirit of air, to whom 

 up-hill and down-hill seem all one. 



In truth, the best way to get Edusa is to watch and 

 mark him down on a flower, then creep cautiously up 

 till within range, raise the net quietly, and strike rapidly 

 downwards over the insect, who usually darts upward 

 when struck at; and, in nine cases out of ten, Edusa 

 will be fluttering under the net. It is not the most 

 heroic style of sport, this, but it fills the boxes ad- 

 mirably. 



The caterpillar is of a deep green colour, having on 

 each side a white line, marked with yellow and orange. 

 It may be sought for in June and July, on various 

 plants of the leguminous order, which form its food, 

 such as None-such Trefoil (Medicago lupulina), Lucerne 

 (M. Sativa), and Clover. 



