THE ENTOMOLOGIST 



Vol. XXXV.] NOVEMBER, 1902. [No. 474. 



VARIATION OF LYC.ENA CORYDON IN NORTH WILTS. 

 By the Rev. C. A. Sladen. 



This species — the " chalk-hill blue," as it is commonly 

 called — occurs in profusion on the downs of North Wilts. Here 

 about harvest-time the foot of the downs, where the turf ends 

 and cultivation begins, is red with the flowers of the knapweed 

 (Centaurea), or "hardhead," as it is sometimes locally called ; 

 and on the flowers of this plant L. corydon swarms in countless 

 numbers, fighting its fellows for standing room, or expanding its 

 wings to the sun. 



In this neighbourhood it varies little in size, though I have 

 occasionally caught little dwarfs of less than an inch in wing- 

 expanse, and other fine fellows of over Ih in. 



The male varies little in colour, but the female varies much ; 

 and this applies both to the upper and the under side. 



Upper side, male type. — Silvery blue, sometimes with black 

 discoidal spot on fore wings : — 



1. With broad black hind margin. 



2. With narrow black hind margin. 



3. With spotted black hind margin. 



In this latter the ocellated spots of the under side show through 

 the hind marginal band on the upper side. The extreme form 

 of this variety has a row of white spots along the hind margin, 

 the black border disappearing. Sometimes specimens occur 

 with the ocellated spots on the hind margin of the hind wings 

 tinged with orange, as in the female. 



All these variations are mentioned by Mr. South in his notes 

 on the genus Lyccena in the 'Entomologist,' vols. xx. and xxxiii., 

 var. 3 being figured on Plate I., fig. 9, in the former volume, and 

 the extreme form of it in Plate III., fig. 5, in the latter. 



ENTOM. — NOVEMBER, 1902. Z 



