Intersexual forms of Plebeius argus L. 227 



at Koyston, although the percentage of intersexes was 

 higher. It is possible that the excess of females and the 

 presence of intersexes may be related phenomena, but 

 observations from other localities are needed. 



At Roystou A. coridon ab. inaequalis Tutt is met with 

 every year, and I have taken it with ab. roystonensis near 

 Tring. This form has blue streaks or large blue patches 

 on one or more wings, often in situations where no blue 

 is found in any female except ab. syngrapha. The blue 

 scales are serrated like those of the female or rounded 

 Hke those of the male, and beneath and around them are 

 scales so deeply pigmented as to appear black or indigo-blue. 

 There are no coarse hair scales and no androconia, nor is 

 there any reduction in size of the wing. In 1920 two or 

 three were taken with the whole of both wings on one 

 side blue of a deeper colour than ab. syngraplia Kefers, 

 and with a very black border. These have no androconia 

 and no hair scales. I regard them as extremely fine 

 examples of ab. inaequalis. I am inchned also to think 

 that a single specimen from Royston, which has all four 

 wings entirely of this blue, should be regarded as an example 

 of this condition present on both sides instead of unilateral. 



Amongst my argus are two which resemble this form 

 of coridon. In both of them the wings on the two sides 

 are equal in size. One has three streaks of serrated blue 

 scales and black imder scales beneath and around them 

 along the costa of the right fore-wing, the other has a 

 short streak of rounded blue scales with many more black 

 ones near the costa of the right fore- wing; but there are 

 no androconia in either. For this aberration of argus v/ith 

 one or more streaks of blue scales, but without androconia 

 or inequality in the size of the wings, and with the coloration 

 of the underside, and the abdomen and genitalia Hke those 

 of a female, I propose the name ab. inaequalis ab. nov. 



It seems to be much scarcer than the other intersexual 

 form, just as A. coridon ab. inaequalis is scarcer than 

 ab. roystonensis. Its occurrence in both species in the 

 colonies which produce the intersexes, suggests that 

 these forms may be related to one another. On this point, 

 too, further observation is needed. 



In the same place I took a very curious specimen. It is 

 a female with wings symmetrical in size and shape, but on 

 the right side the wings are brown except for a few blue 

 scales at the extreme base, on the left they have a large 



