32 BRITISH BUTTERFLIES. 



fig. 12) is a very good illustration of the exact opposite to radiosa, in 

 which the nervures are dark and the interneural spaces blue, resulting, 

 however, in a similar radiate appearance = ab. subradiosa, n. ab.] An 

 aberration of this form is mentioned by Bellier de la Chavignerie (Ann. 

 Soc. Ent. France, 1858, p. 310) as having been taken near Paris. He 

 compares it with the $? of P. meleager. Sladen records (Ent., xxxv., 

 p. 274) that, in 1902, he captured, in Wiltshire, a $ with the veins 

 of the hindwings blue, the intervening spaces being normal in colour, 

 and adds that, in the usual form of blue variation, the veins remain 

 black, whilst the intervening spaces are blue, as is the case in our ab. 

 subradiosa. 



d. ab. semisyngrapha, Tutt, "Brit. Butts.," p. 167 (1896); Lamb., "Pap. 

 Belg.," p. 240 (1902); "Cat. Lep. Belg.," p. 427 (1907); Hodgson, " Proc. Sth. 

 Lond. Ent. Soc," p. 89 (1908). Semibrunnea, Wheeler, "Butts. Switz.," p. 31 

 (1903); Bartel, "Ent. Zeits. Guben," xviii., p. 114 (1904); Kebel, " Berge's 

 Schmett.," 9th ed., p. 72 (1909); Seitz, " Gross-Schmett.," p. 315 (1909); Keynes, 

 "Ent. Rec," xxi., p. 263 (1909). Corydon ab., Barr., "Lep. Br. Is.," pi. xii., 

 fig. lc (1893); South, "Proc. Sth. Lond. Ent. Soc," p. 49 (1906).— With blue 

 base as far as discoidal spot on forewings ; blue from base to outer margin on 

 hindwings (Tutt). 



This is the more usual extreme form of the blue $ taken in England, 

 the hindwing being that of titkonits (syngrapha), the forewingonly blue 

 to the discoidal or just beyond. It appears even then to be confined 

 to certain localities, and to be more particularly abundant in them in 

 certain seasons, especially among the later-appearing examples (mid- 

 September, 1907, at Cuxton). We have taken it not uncommonly on 

 the Hailing and Cuxton downs in various seasons since 1871, and 

 Keynes notes (Ent. Rec, xxi., p. 263) it as specially abundant at 

 Eoyston, one of its Hertfordshire localities, whilst, in other places 

 comparatively near, it is rarely seen ; Eowland-Brown notes it as 

 occurring occasionally among the September $ s near Kimble ; 

 Pickett finds it distinctly rare near Dover, and Hodgson in Surrey 

 and Sussex, remarking that it is usually much less common than the 

 corresponding "blue" $ of A. thetis, although the latter notes the 

 late, cold, wet season of 1888, as an unusually good year for " blue " 

 aberrations in the Brighton district ; 1907 and 1909 are also noted as 

 good years for these forms ; and South reports the form from Eastbourne. 

 One suspects that such are generally rare on the continent, if one 

 judges by the paucity of records. Doleschall says that he gets inter- 

 mediates between sijwiraplia and the type at Briinn in Moravia, a 

 rather vague description, that may refer to other of the blue forms. 

 Several recent authors — Bartel [Ent. Zeits. Guben, xviii., p. 114), Rebel 

 (Berge's Schmett., 9th ed., p. 72), Seitz (Gross-Schmett., i., p. 315), etc., 

 sink this exceedingly fine form as being the same as the merely blue- 

 dusted semibrunnea, Mill. These authors can know neither form, nor 

 could they have referred to Milliere. The two forms are quite dis- 

 similar. 



t. ab. oppoaitd, n. ab. Corydon ab., Sladen, "Ent.," xxv., p. 274(1902). — ?. 

 The forewings blue, the hindwings brown with only a few blue scales, thus reversing 

 the ordinary course of variation in this species. 



This is an unusual form of variation. A specimen is recorded by 



Sladen as having been captured in North Wilts, in 1902. 



k. ab. tithonua, Meig., "Eur. Schmett.," ii., p. ."50, pi. xlvii., fig. 2 (1830). 

 Corydon var., Bergstritsser, "Nom.," iii., p. 3 (ref. to Scbroter) (1779); Hb., 

 •« Eur. Schmett.," pi. 148, fig. 742 (1817 ); H.-Scb., " Sys. Bearb.," i., pi. lxxiv., 



