400 BRITISH LEPIDOPTERA. 



wings is distinctly of this character. A long series, bred by Burrows 

 in 1896 and 1900, exhibits considerable variation. In some examples, 

 the costa of the forewing is much more hollowed, in others more 

 convex than in normal examples ; the apices of the forewings, 

 too, are rounded in the least pigmented specimens ; sometimes, too, the 

 outer margin is distinctly angulated ; in others, again, the wings 

 are distinctly narrower, whilst some examples have the outer margin 

 of the hindwings quite hollow. There is also considerable variation 

 in the tint of the skull-mark on the thorax ; in some specimens the 

 colour of this is whitish-grey, in others dark grey, in others • ochreous ; 

 in the more extreme cases it becomes deep brown, whilst in a few 

 examples the mark is only faintly traceable, having blended, as 

 it were, with the ground colour. We would designate those examples 

 in which it is practically absent as ab. obsoleta, n. ab. The anterior 

 edge of this mark, too, is exceedingly variable, in some specimens 

 forming a simple convex curve, in others a series of three small curves, 

 in others, again, being angulated or pointed. The abdomen varies 

 in tint from pale yellowish to darker orange, which, in some, inclines 

 to brownish. The black longitudinal streak down the centre of 

 the dorsum of the abdomen is also much broader in some specimens 

 than others. On the forewings the basal marking is in some 

 individuals distinctly double, and traceable to the inner margin, in 

 others only the inner line is shown, and this does not reach the inner 

 margin of the wing, whilst in some the marking is concolorous with the 

 rest of the wing. The angulated line, which extends occasionally from 

 the costa to the inner margin, is pale ; usually it is not to be traced 

 in the inner half of its course. The subterminal is less distinct, 

 but very variable in intensity. The brown colouring, extending 

 from the costa along the upper half of the wing to the centre, is 

 very much developed in some specimens, almost absent in others. 

 In three or four examples the wings are badly scaled at the tips, 

 the rest of the wings being unicolorous, blackish. The central spot 

 is very much larger in some specimens than in others. In the 

 hindwings the neural darkening between the two bands is very variable 

 in intensity, sometimes rather closely uniting the two bands. The 

 basal half of the inner band may be strong or weak, or obsolete. 

 The outer band is sometimes weak apically ; the black inclining to 

 greyish, in one specimen, forced in 1893, the left hind wing has a 

 pale, almost obsolete, inner band (Trans. City Loud. Ent. Soc., vii., 

 pp. 3-4). At the meeting of the Berlin Ent. Soc, held November 

 23rd, 1899, Huwe exhibited examples without the inner band of 

 the hindwings, and also some melanic ones, whilst one had the 

 rings of the abdomen almost obsolete and silver-whitish stripes 

 thereon. The most common forms of variation in the character 

 of the bands of the hindwings are (1) The inner band wanting=ab. 

 imperfecta, n. ab. (2) The two bands closely united = ab. conjuncta, n. 

 ab. (3) The outer band continued to the margin = ab. externa, 

 n. ab. Nickerl mentions that he has aberrations with the inner 

 band of the hindwing wanting, and Assmann figures ( ' Schm. Schles., 

 ii., pi. xvii., fig. e) the aberration mentioned by Ochsenheimer 

 (Die Schmett., ii., p. 284) without the inner band of the hindwings ; 

 Gauckler records (Jllus. Zcits. fur Ent., v., p. 282) breeding a similar 

 one at Carlsruhe, in 1900, and another not more than half the size of 



