Intersexual forms of Plebeius argus L. 229 



scales are nearly all rounded like those of a male instead 

 of being serrated, and they are usually grouped in streaks 

 and patches rather than peppered over the wing as they 

 are in coridon. In a very large number blue scales are 

 found in positions where no blue occurs even in the bluest 

 P. argus ah. masseyi Tutt. 



Blue scales often completely replace the orange of the 

 lunules in the fore- or hind-wing and extend beyond 

 the lunules. In some a few blue scales are found amongst 

 the orange ones, or a thin stripe of blue runs right through 

 a lunule. This unusual extension of blue outwards was 

 noted in 46 of my series and probably is present in others. 

 In intersexes with nnich blue near the margin the 

 margin is blackened like that of a male and the fringe is 

 white, or there are white patches in it. This is clearly 

 visible in the figures. Thus the following male characters 

 may be present : — 



(1) androconia, 



(2) rounded blue scales often situated in places where no 



blue is present in the bluest females, 



(3) black margin, 



(4) white fringe. 



The underside is nearly always entirely female in colora- 

 tion. The reduction in size of the blue-scaled wings is less 

 than in coridon unless the blue scahng is very extensive. One 

 specimen, however, has a very small left hind- wing without 

 any blue scales, and a left fore- wing with a blue streak 

 and only a small indentation of the margin adjoining it. 

 In two specimens the antenna on the side with male 

 characters is smaller than the other. Fifty-four specimens 

 have blue on one side only; nineteen of them have blue 

 on one fore-wing only, three on one hind-wing only, and 

 thirty -two on both wings. Four have blue on the wings 

 on both sides, two of them on all four wings, one on both 

 hind-wings and the right fore-wing and one on both fore- 

 wings. There is a higher proportion of specimens with a 

 bilateral distribution of blue scales and androconia than 

 in coridon. I have seen three taken in 1918 with all four 

 wings nearly blue all over, so that the appearance of the 

 upperside was much more that of a male than a female. 

 I have one taken at Dover in 1889 exactly like a male 

 on the upperside except for small patches of orange 

 scales representing part of lunules 1, 2 and 4 on the left 



