236 CHALK- HILL BLUE BUTTERFLY. 



face of the female brown, each wing witli a pale 

 central spot, having a black pupil in the prim ary 

 wings. The under side of both sexes is similar, 

 but the secondary wings in the female are more 

 deeply coloured, and the spots larger and more dis- 

 tinctly marked : the anterior wings whitish, marked 

 nearly as in P. Avion : the hinder ones of a similar 

 colour, gieenish at the base, the ocellated spots ar- 

 ranged in two curved bands, that next the base con- 

 sisting of four, the second, which is placed rather 

 behind the middle, of eight ; in the centre, between 

 these bands, there is an angular white spot; and on 

 the hinder margin a series of black spots, with a 

 white iris surmounted by a streak of orange, and a 

 triangular black spot, with its apex directed inwards ; 

 an oblong white patch connects tliis series with the 

 central band. Fringe white, spotted at regular in- 

 tervals with brown ; on the under side of the secon- 

 dary wings entirely white. 



Somewhat restricted in its distribution, but occur 

 ring in certain localities in gi-eat profusion. It chief- 

 ly frequents districts where chalk abounds, and from 

 having been long found in plenty on a range of hil- 

 locks between Dartford and Darenth Wood, it has 

 received the name of " Chalk-Hill Blue." It inha- 

 bits the vicinity of Dover, the Isle of Wight, " Little 

 Blakenham, Moulton, and Eriswell in Suffolk ;" 

 stone-quarries near Peterborough, &c. &c. The 

 caterpillar, of which we have never seen any de- 

 scription, has been stated to feed on Wild Thyme. 



