RURALIS BETULiE. 279 



II. Females — 



1. With narrow orange patch crossed by black nervures = ab. restricta- 



lineata, n. ab. 



2. With broad orange patch crossed by black nervures = ab. lata-lineata, 



n. ab. 



3. With narrow orange patch not crossed by black nervures = ab. restricta, 



n. ab. 



4. With broad orange patch not crossed by black nervures = ab. lata, n. ab. 



5. The orange markings yellowish in colour = ab. fisoni, Wheeler. 



6. With submarginal series of interneural orange streaks in hind wings 



pointing towards base = ab. cuneata, n.ab. 



Blachiar observes that, in the Swiss examples, the male has often a 

 clear yellowish or greyish shade beyond the black cellular point, and 

 one may say that, in European specimens, the male colour extends from 

 being entirely dark fuscous to others with a moderately denned series of 

 orange ( = ab. spinosae, Gerh.), grey ( = ab. grisea, n.ab.), or whitish 

 (=at. pallida, Tutt) markings, representing an obsolete transverse band. 

 In the females there is great variation in the length and width of the 

 orange bar, and in the intensity of the shading of the nervures crossing 

 it, -some being quite narrow ( = ab. restricta, n. ab.), others quite broad 

 (=ab. lata, n.ab.), whilst both forms are sometimes quite conspicuously 

 lineated by the dark nervures crossing the band ( = ab. lineata, n. ab.). 

 The intensity of the orange is sometimes reduced to a distinct yellow 

 (= fisoni, Wheeler), whilst the best marked females have a transverse 

 interneural series of wedge-shaped or cuneate orange streaks, parallel 

 with the hindmargin of the hindwings, and pointing towards the base 

 ( = ab. cuneata, n.ab.). Adkin notes (in litt.) that " a large number, 

 bred from larvae taken in the New Forest, exhibit considerable varia- 

 tion ; the males, as to the pale marking on the forewing, in some cases 

 nearly obsolete, in others of considerable size, and extending in some 

 instances to three separate patches ; in the females, the orange marking 

 of the forewing, which usually extends across about three-quarters of the 

 width of the forewing, is, in some cases, limited to less than one-half 

 and slightly broken. The hindwings are also slightly radiated with 

 the orange-colouredmarkings in some instances." There is distinct and 

 marked size-variation in the European specimens of this species. Our 

 British specimens, captured wild and not bred, are somewhat similar 

 in size to those of central Europe, occasional ones being a little 

 beyond the average. The usual size of European examples is 

 between 35mm. and 40mm. ; our long British series varies from 

 30mm. -38mm. Burrows reports {in litt.) " an enormous male, quite 

 If ins. in expanse, and as large, if not larger, than the ordinary 

 size of the females," and, for a British example, this maj^ be considered 

 fairly large, though quite a pigmy compared with the eastern var. crassa, 

 which measures 56mm. (against the 34mm. of this example). Similarly, 

 the specimens of the lateral valleys on the south side of the Valais, are 

 normally from 32mm. -35mm. in expanse (Wheeler), and Aigner-Abafi 

 gives the average size of the Hungarian examples as 30mm. -35mm., but 

 the males taken at Certosa di Pesio, in 1892, average l-75in. = 44mm. 

 in expanse (Norris). Kaye records feeding up some larva?, in 1906, in 

 closed tin boxes, on plum, and the resulting butterflies were especially 

 large, the largest female being 42-5mm. in expanse ; the females, too, 

 had quite a small amount of orange on the forewings (Proceedings of 

 the South London Entomological Society, 1906-7, p. 73). Dwarf 

 examples were exhibited at the meeting of the City of London 



