CYAN IRIS SEMI ARGUS. 255 



somewhat into violet; on the margin, all four wings are bordered with 

 black, and have beyond a narrow white border. The $ is, on the 

 upperside, quite dark brown, on the underside dark greyish-brown, but 

 otherwise marked just like the $ . The butterfly appears in June in 

 gardens and meadows, but is not nearly so common as argus, Linn, 

 (von Rottemburg). 



Imago. — 27mm. -32mm. $ . Deep purple-blue ; with a more or 

 less wide black marginal border ; the nervures darker than ground 

 colour ; the discoidal lunule generally visible ; fringes whitish ; under- 

 side grey. $ . Brownish-fuscous, underside grey-brown ; fringes 

 grey, paler at apex of forewing. Beneath, in both sexes, a single sub- 

 median row of white-margined ocellated spots across fore- and hind- 

 wings ; the discoidal lunules also edged with white : on the hindwings 

 usually one costal spot between the discoidal lunule and the base ; the 

 forewings without basal spots. 



Sexual dimorphism. — The sexual colour difference is most marked 

 in this species. In their more typical forms the $ may be said to be 

 of an uniform purple-blue, with darker margin and nervures, the $ 

 unicolorous fuscous, but sometimes with a few blue scales towards the 

 base, at other times, though rarely, well-scaled with blue ; the underside 

 of the $ is grey of some shade, the $ grey with a distinct brown tinge. 

 In the more extreme forms the S is much brighter blue, whilst the ? is 

 marked on fore- and hindwings with orange lunules ; the underside, 

 too, in these extreme forms, shows the $ much more strongly marked 

 with orange than the $ . In size there is not much difference between 

 the sexes ; on the whole the $ s are quite as large, or larger, than the 

 $ s, in some cases considerably larger. Aurivillius says (Bih. Svensk. 

 Ah. Handl., v., p. 23) the S differs from the ¥ by its blue coloration, 

 and by the androconia, which are arranged in about eight rows ; they 

 are narrower than in Celastrina argiolus, noticeably convex at the 

 edges, and hence appear pear- or bottle-shaped. Pierce notes (in litt.) 

 that " there are eight rows of androconial scales, which are oval in 

 shape, and measure -001 in. x -0007 in. The other $ wing-scales 

 are (1) the transparent scales, -004 in. x '002 in., of a bright yellow 

 colour and quite plain, (2) darker scales, slightly, not deeply, 3- and 

 4-lobed. The underside scales are very irregular and may be 2-, or 3-, 

 or 4-pointed." 



Gynandromorph. — The only record that we can discover of gynan- 

 dromorphism in this species is the following : — 



(a) Complete gynandromorph. Left wings ? , right wings £ . The right 

 forewing is somewhat broader and shorter than the left. The right half of the body 

 has the bluish scales that characterise the $ , but the left is black and hairy like 

 the ? . Caught by H. Bnnge, July 13th, 1906, in a meadow near the Wienebiittel 

 farm (Bunge, Ent. Zeits. Guben, xx., pp. 159, 225, with fig., p. 256). 



Variation. — Compared with many of the allied species, and 

 considering its great distribution, C. semiargus affords a comparatively 

 small amount of variation throughout its range from Portugal to 

 Amurland, except in a comparatively limited district in the Orient, 

 extending from the Balkan Peninsula to Persia. Outside this area, 

 which requires to be treated separately, the typical form, with but 

 slight modifications, occurs. Throughout Europe and Asia, there can 

 be no doubt the " plain " or lowland examples are distinctly of a 

 brighter blue than are those from the Alps, even only at a moderate 



