76 LEPIDOPTERA. 



the under surface of the leaves, generally in patches, preferring 

 the younger shoots, and causing the upper side of the leaves 

 to wither and tiirn brown. 



Pupa short and rather thick, smooth, rounded in front and 

 on the back, blue-green or greenish in front, yellowish-pink 

 on the back, with a deep pink double stripe enclosing a white 

 one, down the sides. On the ground, sometimes unattached, 

 at others protected by a leaf drawn together by a few threads, 

 or occasionally attached by the tail and a cincture. 



A long controver.sy took place some yeai's ago upon the 

 subject of the food-plant of this larva, the supposed re- 

 striction of the southern form to Erodium, and of the northern 

 to Helianthcnuin, being held to be a strong point as evidence 

 of the distinctness, as species, of the two forms. This, how- 

 ever, was disproved by the late Mr. W. Buckler, who 

 obtained, through Mr. W. R. Jeffrey, of Ashford, eggs of 

 (((jcstis upon Hclianthciimm, and reared the larvffi to 

 maturity ; and also larvffi upon the same plant from Mr. 

 Robson, of Hartlepool, from which he reared all three forms. 

 It appears, however, from Mr. Robson 's observations, that the 

 northern forms — Salmacis and Artaxcrxcs — are jjroduced only 

 from hybernated larvte, and that farther north, where typical 

 agcstis are not found, there is but one generation in the 

 year. 



Not a very active butterfly ; flits quietly about warm hol- 

 lows on hillsides and open fields, or the sheltered sides of 

 sandhills, and may readily be mistaken for the female of one 

 of the other species. Very fond of resting and sleeping on 

 tall grass stems, and particularly on the rolled-up leaves of 

 the marram-grass (Ainiiuqihila arundinacca). 



The typical form is abundant in the southern half of 

 England — on chalk hills among the Helicmthemum , and on 

 coast sandhills and inland sandy places, wherever Erudium 

 is plentiful. Mr. A. H. Clarke assures me that it was 

 formerly abundant at Wormwood Scrubs, close to London ; 



