236 CHALK-HILL BLL’E BUTTERFLY. 
face of the female brown, each wing with a pale 
central spot, having a black pupil in the primary 
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. Arion: the hinder ones of a similar 
colour, greenish 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 this 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 great 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. 
