100 LLOYDS NATURAL HISTORY. 



occurring in May and August, like the allied " Blues," and it 

 is fond of chalky districts, though less exclusively confined to 

 them than are P. corydon and P. thetis. The Northern and 

 Scotch forms are noticed under separate headings. The variety 

 P. allous was figured from a specimen in which the usual red 

 sub-marginal spots were wanting. 



The Brown Argus measures an inch or a little more across 

 the fore-wings, which are dark brown on the upper side in both 

 sexes, with a fine silky gloss, and white fringes. There is a 

 sub-marginal row of deep red spots on all the wings, and a 

 black discoidal spot on the fore-wings. The under side is greyish- 

 brown, with no bluish tinge towards the base, and no basal 

 spots on the fore-wings, but three are present on the hind-wings. 

 There are discoidal spots, a central row of spots beyond (all 

 conspicuously ringed with white), and the sub-marginal reddish 

 spots connected into a band, edged within by a black line of 

 crescents. Beyond this the wing is white, with a row of black 

 dots outside the reddish band, and a black line at the base of 

 the fringes ; a white dash runs from the middle of the hind- 

 wings to the reddish band. 



The larva is green, with white hairs, a dark dorsal line, and 

 a pink line over the spiracles. It feeds on Helianthemum 

 vulgare and EroJium cicutarium. The green pink-striped pupa 

 is generally found on the ground amongst leaves. 



V. THE DURHAM ARGUS. POLYOMMATUS SALMACIS. 

 (Plate XL VIIL Fig. 3 <J , 4, 5 ? ) 



Polyommatus salmaris, Stephens, 111. Brit. Ent. Haust. iii. p. 

 235, note (1831); Westwood & Humphreys, Brit. But- 

 terflies, p. 115, pi. 37, figs. 1-3 (1841). 



Polyommatus agestis, var. salmacis, Barrett, Lepid. of Brit. Isl. 

 i. p. 74, pi. 10, figs. 3-- 3 / (1892). 



This is the usual form of Polyommatus akxis found in the 



