THE LARGE BLUE. 179 



The Large Blue (Nomiades arion). 



The butterfly on Plate 117, Figs. 1-6, is the largest "Blue" 

 found in this country. All the wings on the upper side are deep 

 blue, and their outer margins are bordered with blackish ; the 

 discal spot, and a row of spots beyond, are black-; the hind 

 wings have a row of black dots on the outer margin, and 

 sometimes, and especially in the female, there is a series of black 

 dots just beyond the central area ; the fringes are white. The 

 under side is greyish tinged with blue towards the base of each 

 wing, but covering nearly the whole of the basal third of the 

 hind pair ; the spots are black ringed or edged with white ; on the 

 fore wings there are two in the discal cell and a row of six 

 beyond ; on the hind wings there are four or five before the 

 discal spot, and a series of seven beyond ; all the wings have 

 a double marginal series, and some black dots at the ends of 

 the nervules. Sometimes the wings have a purplish tinge, and 

 this is more usually so in Gloucestershire specimens. The 

 chief variation is in the number and the size of the spots ; these 

 are occasionally only faintly in evidence, but more rarely perhaps 

 those beyond the discal spot on the fore wings are of large size 

 and bar or wedge-like in shape ; the smaller cell-spot is often 

 absent. A dwarf form is stated to occur at times in all localities . 



The complete life-history of this species has yet to be ascer- 

 tained ; no one seems to be acquainted with the caterpillar 

 after hibernation. Pretty much all that is known of the early 

 stages has been worked out by Mr. Frohawk, who has published 

 some very interesting accounts of his observations in the 

 Entomologist for 1899 and 1903, and from these the following 

 details have been obtained. 



The egg (Plate 116) is bluish-white in colour, and is laid 

 singly among the buds of wild thyme {Thymus serpyllum). 



Caterpillars hatched on July 10 from eggs received the 



