POLYOMMATUS. 9I 



to it are peculiarly attached to the chalk or lime-stone in Eng- 

 land, though of more general distribution on the Continent. 

 They may often be all found flying together in favourable 

 localities on the South Downs. 



I. THE CHALK-HILL BLUE. POLYOMMATUS CORYDON. 

 {Plate XLVII. Figs. 5, 6.) 



Papilio corido7t^ Poda, Mus. Groec p. 77 (1761); Scopoli, 



Ent. Cam. p- 179 (1763), 

 Fapilio corydon^ Esper, Schmett. i. (i) p. 335, pi. 33, fig. 4 



(1777); 1.(2) p. 134, pi. 79, fig. 1(1782); Hiibner, Europ. 



Schmett. i. figs. 286-288 (1803?). 

 Fapilio fiphys, Esper, Schmett. i. (2) p. 6, pi. 51, fig. 4 (1780). 

 Polyojiiniatus corydon, Godart, Enc. Meth. ix. p. 693, no. 



227 (1823) ; Stephens, 111. Brit. Ent. Haust. i. p. 88 (1828) ; 



Kirby, Eur. Butterflies and Moths, p. 48, pi. 14, figs. 



Za-c (1879); Barrett, Lep. of Brit. Isl. i. p. 85, pi. 12 



(1892); Buckler, Larvae of Brit. Lepid. i. p. 191, pi. 14, 



fig 3 (1886). 

 Lyccena corydon, Newman, Brit. Butterflies, p. 131 (1881); Lang, 



Butterflies Eur. p 121, pi. 26, fig. 6 (1882). 

 Var. Lya^na corydon^ var. albicans^ Boisduval, Gen. et Ind. 



Meth. p. 12, no. 96(1840); Herrich-Schaffer, Schmett. 



Eur. i. App. p. 27, figs. 494, 495 (185 1); Lang, Butterflies 



Eur p. 122, pi. 26, fig. 8 (1882). 



The Chalk-Hill Blue is common throughout Southern and 

 Central Europe and Western Asia Minor. In England it is 

 common in many places, but local, and is most frequently met 

 with in the chalky districts of the south, whence it derives its 

 name. On the Continent it is double-brooded, like most of 

 the allied species ; but it appears to be single-brooded in Eng- 

 land, appearing about the middle of July, at the same time that 

 the second brood of the otlicr species is beginning to appear. 



