334 BKITISH BUTTERFLIES. 



The slightest attention, however, to von Kottemburg's original descrip- 

 tion of thetis, should have saved both authors from so palpable a 

 blunder. Bergstrasser then further asserts (op. cit., iii., p. 35) that 

 his thetys (pi. lv., figs. 5-6), salacia (pi. 1., figs. 1-2), pampholyge (pi. 

 xlvii., figs. 1-2), venilia (pi. 1., figs. 3-4), and oceanus (pi. liii., figs. 3-4) 

 were united by von Rottemburg under the name of thetis, but this is 

 not so, for, although salacia and venilia are two $ forms of the insect 

 we are considering, thetys, pampliolyge, and oceanus are merely different 

 2 forms of P. icarus, and quite excluded by their fringes from von 

 Kottemburg's description of thetis, as already noted. Borkhausen 

 described (Sys. Besch., ii., p. 228) his thetis from Landsberg-on-the- 

 Warte, whence came von Kottemburg's examples ; his $ and 2 thetis were 

 also two 2 forms of this species, but he enquires very pertinently how thetis 

 is to be distinguished from bellargus, especially the 2 • In Britain, the 

 2 s are particularly variable, both as to ground colour, quantity of 

 blue scaling, number and intensity of the orange-red lunules, etc. Of 

 the Swiss examples, Keverdin notes (in litt.): The ground colour is 

 generally brown, with a slight reddish tone, rarely it is almost black ; 

 the specimens with blue scales divide up into many groups, e.g., (1) 

 those with only a few blue scales at base of wings ; (2) with the base 

 of the forewing and the antemarginal region of the hind wings blue ; 

 (3) those that are true ceronus, the nearest Swiss examples to which 

 have the blue occupying the whole of the forewings except the costa 

 and the outer margin, and the whole of the hindwings except a more 

 or less wide band on the front margin ; the blue tint is particularly 

 striking on the hindwings, forming blue lunules surmounting the 

 orange lunules ; these latter are smaller on the forewings than on 

 the hindwings, and decrease as they near the apex of the wing, the 

 front lunules being also less .defined than the hind ones, and sometimes 

 only indicated by narrow, indistinct, whitish streaks, parallel to the 

 outer margin ; usually these, i.e., with the faintest lunules, are the most 

 blue examples ; in the hindwings the lunules, varying from fulvous to 

 almost red, also decrease in size from the apex backward, etc. ; the 

 black marginal kernels are semicircularly edged behind with white or 

 blue; in one example the semicircles are invaded by black, which gives 

 it a striking appearance, whilst, in another, the black terminal line, 

 instead of running regularly on, breaks into the blue semicircles to the 

 neural area, and so diminishes the extent of the blue. Blachier notes 

 (in litt.) the Geneva examples as brown, with red-, orange-, or apricot- 

 coloured lunules on all the wings, or only on the hindwings, the latter 

 specimens usually strongly scaled with blue ; the bases of the wings 

 are usually blue-scaled, but some are entirely brown to the base ; the 

 red lunules of the hindwings rest on larger or smaller black spots, 

 whilst between the marginal line and these spots, are small, blue or 

 white, arcs; the red lunules themselves are sometimes surmounted with 

 pale or dark blue crescents. Blachier further mentions an extreme 

 blue 2 in which there are no fulvous lunules on the forewings, and 

 scarcely any trace thereof on the hindwings. Courvoisier says that 

 the 2 s on the Simplon are often strikingly blue ; on the other hand, 

 Frey states that the alpine 2 s are nearly always uniformly brown, or 

 only very slightly suffused with very pale blue, whilst Zeller states 

 (Stett. Knt. Ztg., 1877, p. 292) that the 2 s found at Bergiin are brown 

 in colour, with scarcely any blue scales, a few only being sometimes 



