402 BRITISH LEPIDOPTERA. 



month, and the same author also asserts that larvae living on lime 

 produce brighter-tinted moths, whether green or brown, whilst those on 

 elm give quite dark specimens. Standfuss says the green form is bred 

 from Ulnius camfiestris. Hoffmann and Keller note that at Stuttgart 

 the brown form appears commoner than the green. Richter says that 

 in Dessau those reared on birch produce brown aberrations. With 

 regard to the variation in the transverse band, Bartel observes that it 

 varies greatly in width and ground-colour, whilst the outward 

 angulation is sometimes pointed, and at other times blunt ; in some 

 green examples the band is lightly edged with darker coloration ; 

 when complete it extends from the front margin to the inner edge, 

 in most examples it is interrupted and broken up into two spots, of 

 which the upper is the greater and may be separated from the 

 costal margin, whilst the lower one is usually just away from the inner 

 margin; in some examples the spots are only just separated by the 

 nervure running between them, whilst in others the ground colour 

 extends for a considerably greater width separating the two spots 

 much more completely ; the costal spot runs much below the middle 

 of the wing, and is connected occasionally on its lower edge with the 

 small spot of the same colour extending from the inner margin, the 

 latter (small spot) being extremely narrow and almost like a stroke, 

 the upper, however, also sometimes becomes very small. The area 

 in front of the twice-angulated outer edge is usually dark-coloured 

 and inwardly edged with a lighter border; the band is sometimes 

 only indicated in outline or is reduced to mere traces ; in others it shades 

 off into the ground-colour. Some of the most marked aberrations have 

 been described and figured by Clark ( Ent. Record, i., pp. 327 — 

 328, pi. A., figs. 1 — 10). Speaking of the general variation, he 

 writes : " If we look at our three British Amorphid species, we note 

 that Amorpha populi has a more or less developed band passing trans- 

 versely across the centre of the anterior wings ; Smerinthus ocellata has 

 a fairly developed dark blotch on the costa of the anterior wings, 

 followed by a smaller blotch on the inner margin, these two blotches 

 undoubtedly showing the origin of a central band in the genus ; whilst 

 in Mimas tiliae the central band is always dark on a pale ground, 

 and hence stands out conspicuously. Perhaps the most common form 

 of the band in this species consists of a large costal blotch, and a large 

 blotch on the inner margin just united at the centre of the wing, 

 as in pi. A., fig. 10. Sometimes this band, however, is quite 

 complete, and occasionally entirely absent, as pi. A., fig. 1, will 

 show. The most interesting feature with regard to this is the 

 occasional asymmetrical character of the band as in figs. 2, 4 and 

 6, whilst figs. 3, 5, 7, 8 and 9, although all showing some abnormal 

 condition of the band, are perfectly symmetrical. A structural 

 point to which I would also draw attention is the variation in the 

 outline of the anterior wings. This species always appears to unite 

 the sinuous outline of A. populi with the centrally concave outline 

 of S. ocellata, the latter feature being generally strongly developed, 

 but, in the specimens figured, it will he noticed that figs. 1 and 4 

 have this character reduced to a minimum, whilst fig. 8 has it 

 very strongly developed. There is a considerable amount of varia- 

 tion also in the width of the double transverse basal line (compare 

 figs. 1 and 3) ; that of fig. 7 is, however, practically obsolete, and 



