TRIFIDM. 329 



brown, but in the vast majority the grey-brown hind 

 marginal band is more or less visible. 



The underside of the fore wings is far more constant than 

 the upper, the hind marginal space, beyond the dark stigma 

 and stripe, being always pale and shining, often white. By 

 this the species may be recognised when all the characters of 

 the upper side seem to have been lost. 



On the wing at the end of July, through August and in 

 the beginning of September. 



Larva cylindrical, tapering a little at the first three 

 segments, the head being the smallest, though rounded and 

 full in outline ; it tapers also in the two hinder segments ; 

 the segmental divisions and subdividing wrinkles are very 

 well defined. Head and dorsal plate pale brownish-bufE, 

 body of the same colour when full grown, dorsal line bluish- 

 grey, edged with darker grey ; subdorsal line whitish-grey 

 or pale grey, edged above with a strongly contrasting dark 

 greenish-grey line ; midway between this and the spiracles 

 is an interrupted undulating whitish-grey line ; spiracular 

 stripe broad, greyish-white, having a fine dark grey line 

 running through it ; spiracles black ; raised dots dark 

 brown. 



When young it is rather long and slender, but as it 

 approaches half growth it becomes tolerably stout, and when 

 full grown is very decidedly plump. The general colouring 

 of the body up to more than half growth is a lively glaucous- 

 green on the back and rather bluish or greenish-grey on the 

 sides. Soon after half growth it comes to be parti-coloured 

 for a time, the front segments remain green, whilst a patch 

 of ochreous tinges the back of the hinder segments ; by-and-by 

 this, by degrees, spreads below and extends gradually forward, 

 keeping pace with the growth of the larva until maturity, 

 when the colour is as already described. (W. Buckler.) 



September to June or even July on Aira ])V(£cox, Triiicmii 

 jimceion, Artnaria j}fploidts^ Viola, and other sand-hill 



