PLEBEIUS ARGUS. 171 



both pairs of wings are as in the ? , perhaps a little less dark on the right than the 

 left, the difference rather arising from the inequality in size. The markings depart 

 from the type in that the two black ocelli near the anal angle of both hindwings 

 are united by a black streak in which they disappear entirely. The markings 

 of the anterior wings differ in that the right has basally, near the lunule, a black 

 dot situated in a white streak starting from the base, a slight trace of this white 

 streak is also seen on the left, whilst in the type the streak and dot are entirely 

 wanting. The antenna of the left side is a little shorter than that of the right. The 

 abdomen appears externally that of a ? . I am not able to describe the sexual 

 organs, a description that ought to be made. Captured August 6th, 1899, at 

 Wildenhain near Torgau* (Heyne, Ins. Borse, 1899, p. 206 ; Rev. Mens. Soc. Ent. 

 Namur, 1901, pp. 23-24). 



There are many undescribed examples in our best British collections. 



Webb records (Ent., xxi., pp. 133-135) "several gynandromorphous 



specimens " of this species in his collection, presumably, from the 



coDtext, all taken " near Dover, in 1887," which is surely of sufficient 



importance to warrant a more detailed report ; with regard to these, 



Barrett observes (Brit. Lep., i., p. 70) that Webb has gynandromorphous 



specimens in his collection "some with the right side J , others the left 



(op. cit., pi. xi., fig. lb) ; and of these, some have dashes of bright blue 



in the brown of the $ side ; in one case, the abdomen is furnished with the 



genital organs of both sexes ; these gynandromorphous specimens are 



further remarkable in that the wings on the $ side are larger than 



those on the $ , whereas, in perfect ordinary specimens, the $ is the 



larger insect. Similar gynandromorphous examples exist in the 



collection of C. A. Bnggs." It is recorded (Ent. Rec, viii., p. 272) 



that, when the " Briggs' coll." was sold, several gynandromorphous 



examples of this species were disposed of at 7s., 6s., 6s., 8s., 8s., and 



22s. per pair. Mr. T. Briggs says that these six pairs went into the 



" Mason," " Maddison," " Booth," " Sheldon," " Maddison," and 



"Booth" collections respectively. The "Mason" examples have 



already been disposed of, one of which was bought by Dr. Keynes, who 



reports on it as follows : 



ir. Left side typical g . 11mm., right side typical ? , 18mm. Underside on ? 

 side with the spots slightly larger, and iridescent spots more apparent. 



The " Maddison " examples were recently purchased hy Mr. L. W. 



Newman (for the "Bright coll."), who reports: 



(p) Right side i , left side ?, "Dover." Possibly this or the next is our 

 example y (anted p. 170), "Dover" and "Folkestone" being synonymous as a 

 locality for this species. 



(<r) Eight side j , left side ? , " Dover." 



(t) One with the external" sexual colours much mixed up on both sides. 



(v) Not gynandromorphic at all. 



Mr. Sheldon writes that the two specimens he bought are merely $ s 

 with a certain amount of blue coloration, and that amount different 

 on each. Gillmer states (Soc. Ent., xx., p. 131) that the specimen 

 captured June 20th, 1902, by Leonhardt, near Hiiningen in Upper 

 Alsace, and described by Schultz (Berl. Ent. Zeits., xlix., p. 81) as 

 gynandromorphous, is merely a blue-tinted $ . Simimilarly, the ab. 

 diiplex, Ckll. (described postea), was first recorded as a gynandromorph. 

 Variation. — The study of the variation of Pleheius argiis (aeyon) is 

 of the greatest interest, although it presents considerable difficulty for 

 its intelligible treatment. No species with which we have yet had to 



* Except for the difference in size of the wings on the two sides, which point to a 

 .sexual difference, one might suppose from the description tbat this was another 

 dimorphic ? similar to that described ported as ab. duplex. ■ ■ ■ ■ 



