90 



BKITISH BUTTEKFLIES. 



Original description. — Papilio Plebeius rubi. Alis dentate- sub- 

 caudatis ; supra fuscis, subtus viridibus. [Fn. Suec, 806. Alb., Ins., 

 t. 5, f. 8. Wilk., Pap., 62, t. ia, 2. Pet., Gaz., t. 2, f. 11. Habitat 

 in Iiubo aculeato. Papilio hexapus, alis rotundatis integerrimis ; 

 subtus viridibus immaculatis. If. Oel. 7. [Papilio argo similis, alis 

 immaculatis supra cyaneis. Pet., Gaz., p. 6, t. 2, f. 11.] Papilio 

 minor ; superne fuscus, inferne viridis.] Descr. Corpus cinereum. 

 Antennae et pedes nigri annulis numerosis albis. Alae supra fusco- 

 nigricantes, subtus virides, in alis secundariis, juxta marginem 

 superiorem, punctum album. Oculi ante et postice lineola alba 

 notati. Magnitudo argi (Linne). 



Imago. — Anterior wings, 23nmi.-33mm. in expanse ; unicolorous 

 fuliginous-brown, witb black nervures; the androconial brand variable ; 

 sometimes trace of orange marginal line near anal angle ; the fringes 

 of almost the same tint as the ground colour. Posterior wings of the 

 same ground colour, with crenate outer margin, slightly extended to 

 form anal tail ; hind margin finely bordered with dark ; fringes in 

 crenulations pale, with dark patches at end of nervures. Underside 

 of all wings green, with a more or less incomplete transverse row of 

 white spots crossing both wings just beyond the middle; sometimes 

 slight trace of white median spot ; outer margin of hind wings sometimes 

 edged narrowly with brownish-orange, extending at ends of nervures 

 into fringe ; the fringe in the marginal crenulations white or whitish ; 

 the anal tip with tuft of darker scales. 



Sexual dimorphism. — There is no difference in the colour of the 

 sexes, nor markedly in the shape, although the body of the $ appears 

 a trifle stumpier than that of the g , and the abdomen is markedly 

 heavier. The $ , however, is characterised by the presence of a small 

 oval area, filled with specialised androconial scales, placed just within 

 the apical corner of the median cell, as in the Strymonid species. 

 Compared with these Aurivillius says (Bidrag Sv. Vet. Ak. Handl., v., 

 p. 22) " the scales are somewhat broader and shorter, but have the 

 same oblique base and even edge. As in the other species, the wing- 

 membrane is, at the position of the spot, concave on the upper, and 

 convex on the under, side. The similarity of the androconial scales 

 in w-album, pruni, rubi, etc., to ordinary scales, leads one to suppose 

 that the allied species, in which the former have not yet been dis- 

 covered, may possess such, having been hitherto overlooked because of 

 the similarity." Among our British examples are some with the 

 androconial patch quite black, others greyish-brown, and almost lost 

 in the ground-colour, others quite whitish ; the palest we have ever 

 seen characterised a specimen taken at Chattenden, May 19th, 1888, 

 which is of a quite whitish-ochreous tint, and was taken with other 

 examples quite normal in this respect. Of three $ specimens, bred 

 February 26th-28th, 1907, one has the "brand" black and dull, another 

 black but shining, whilst a third has it so bright and shining, that, though 

 really black, one would sometimes say it was white. All the specimens 

 are of a brownish ground colour, thus showing up the brand strongly. 

 The androconial brand, therefore, is usually black, but sometimes pale 

 or almost white, but the latter only in some lights. The patch 

 consists of black scales with rounded ends, unlike the other scales, 

 which have serrated ends. A specimen with nearly white patch (in 

 some lights), which presented the pale colour when freshly emerged 

 from the pupa as well as when preserved, showed the tips of these 



