320 



BKITISH BUTTERFLIES. 



very many species, including those of the genus Everes, found in the 

 north temperate zones of both hemispheres, and the widely distributed 

 Lamjndes, are thus provided. The subfamily is particularly charac- 

 terised by the remarkable androconia, or " battledore scales," 

 distributed over the upperside of the wings of the males, and not 

 collected into special patches as in the Ruralidi. It is asserted that the 

 dark species — Aricia, etc.- — -possess no androconia, but one suspects that 

 they may be present, though not discernible, against the dark ordinary 

 wing-scales. Speyer has noted (Isis, 1843, pp. 175-176) that the fore 

 and middle tibias of many European Lycsenids bear, at the top, above, 

 a horny bristle of variable length, extending over the basal tarsal joint, 

 its presence or absence sometimes being remarkable in closely allied 

 species, e.g., bellargus and corydon. Scudder asserts that this tibial 

 bristle is never present in the Chrysophanids or Theclids. 



In 1868, Watson published" (Mem. Lit. Phil. Soc. Manch., 3rd 

 series, iii., pp. 128 et seq.) some notes on the " plumules," or so-called 

 "battledore scales," of the Lycaanids. These are androconia, or male 

 scent-scales, and they vary much in their development in different 

 species, but must be examined in freshly-emerged examples if any real 

 knowledge of their character is required. As is w 7 ell known, the males 

 of many of the Lycamids are blue in colour, and in these they are 

 usually easily discovered ; in those with brown males the androconia 

 have not been discovered. Watson observes that these plumules are 

 attached to the wings by an apparently hollow peduncle. They are 

 he says, balloon- shaped, have striae-like ribs, suitable for binding, 

 strengthening, and distending or contracting their balloon-like 

 forms ; these ribs, he adds, are more or less beaded or articulated, 

 so that, by them, different scales are bound or bent in various 

 ways. The end opposite to that of insertion is closed, or covered 

 with apparently ciliary apparatus, and they lie in rows between 

 and under the ordinary scales, which may, therefore, be elevated 

 or depressed at the pleasure of the insects, by the regulated infla- 

 tion of the plumules. They differ in separate species in every 



* Watson observes (op. cit., pp. 261-262) : " The best way of collecting and 

 mounting is by gently pressing the wing of the insect against a glass slide, by which 

 means a sufficient quantity of the scales will adhere. To get a clean mounting, it 

 is necessary to brush off the dirt which may be on the wing with a camel-hair 

 pencil, but then care must be taken that the pencil does not convey scales to slides 

 of other species. In fact, suspicious care must be used when mounting a number 

 of slides, as the light scales will often be floating in the air, and alight 

 unexpectedly on the slide which is under operation. Then cover with a thin glass 

 and fix with paper. In some small insects it is more convenient to take off the 

 scales, in the first instance, on the thin cover, and then to affix it to the slide. 

 The plumules are mostly of so delicate a membranous structure, and so deficient in 

 pigment, as to become too transparent (and sometimes almost invisible) in Canada 

 balsam, but it may be used with good effect where they carry some amount of 

 pigment, and the structure of those of the Lycamids is thereby beautifully shown, 

 although these are amongst the most hyaline. In some genera and species they 

 are so small, and so finely striated, as to make an ^-inch object-glass desirable to 

 resolve them satisfactorily, or at least a ^-inch, with a B or C eye-piece, while 

 a £-inch is sufficient for others. The stria particularly should be observed with 

 high powers. Occasionally, scales of different species appear identical under a 

 low power, but a higher one reveals a complete difference of structure. The 

 plumules are generally to be found on the upper surfaces of the wings, sometimes 

 they are most abundant on the primaries, sometimes on the secondaries, usually 

 in, or near, the discoidal cells of both wings, but are, occasionally, very strangely 

 placed." 



