202 LEPIDOPTERA. 



of mountain limestone on the Pembroke coast. Sometimes 

 the altitude at which it is found seems to have a striking 

 effect upon its coloration, as, for instance, at the Cheesering, 

 near Liskeavd, Cornwall, where it is found upon a high hill, 

 and is much brighter in colour (according to Mr. G. C. 

 Bignell) than in the valleys below Dartmoor, and at Ivybridge, 

 Devon. The male flies about its favourite marshy fields 

 tolerably briskly when the sun is hot, though it is a lazy 

 species, and extremely fond of sunning itself upon the flowers 

 of yellow composite plants — Aparrjia, Hypochccris, &c. — and 

 lays back its fore wings, so as almost to cover the hind, as it 

 basks. This habit is particularly observable in hot, close 

 weather, when clouds follow the sunshine. The female is 

 much heavier and more sluggish, and usually sits upon 

 its food plant, or on the neighbouring grasses, except 

 when laying its eggs. In some seasons, but not too fre- 

 quently, either from weather especially favourable to its 

 larva, or more probably from some failure of its destructive 

 parasites, it becomes very plentiful, and then overflows from 

 its restricted haunts, searching out fresh suitable spots, 

 and even making its way along the wood paths where its 

 food plant grows. No doubt this enables it to form fresh 

 settlements, and so resist the constant attacks of too zealous 

 admirers. From some cause, however, it has disappeared 

 from several formerly favoured haunts. Mr. J. J. Weir 

 remembers it in the gi'eatest abundance in Sussex, where it 

 is now very rare, and this is distinctly attributed to the 

 greediness of a grasping collector. But other influences 

 must be at work, as at Hartlejiool, where Mr. Eobson remem- 

 bers it, thirty years ago, quite commonly, and also that it 

 suddenly disappeared. Dr. Manders records, moreover, that 

 around Marlborough, Wilts, it used, at one time, to be regu- 

 larly found in several restricted spots, but gradually became 

 rarer, and in 1870 had become apparently extinct. None 

 were seen there until 1881, when stray specimens reappeared 

 iu various places. There is no reason, I think, to fear that 



