X INTRODUCTION. 



superficial difference in the appearance of the specimens, which possess 

 or are devoid of such a row of spots. These spots are frequently very 

 clearly developed in Aplecta nebulosa, A. tincta, A. occulta, Hadena 

 adusta, H. glauca, H. dentina, Agrotis cursoria, A. tritici, A. valligera, 

 Charrpas graminis, Aporophyla australis, Agriopis aprilina, Folia chi, Dinn- 

 thcecia albimacula, Xylophasia polyodon and Tceniocampa munda, whilst 

 many other species exhibit variation in this direction in a lesser degree. 

 Sometimes these spots are incorporated, as it were, with the subtermi- 

 nal W-like line, and give this a special character, whilst at other 

 times, but much more rarely, the cuneiform spots are carried out be- 

 tween the nervures to the outer margin, thus forming a series of long 

 dashes. I notice that this occurs occasionally in specimens of Aporo- 

 phyla australis, Agrotis valligera and Charceas graminis. The line just 

 outside the reniform, commonly known, from its shape, as the 

 shouldered or elbowed line, is worthy of notice, being frequently com- 

 posed, in its simplest form, of dots, and in its more complex forms of 

 a series of lunular arches with almost all intermediate forms, in the 

 same or in different species. The metallic markings in Plusia are 

 worthy of extended notice, but I will simply remark that the two 

 central spots of Plusia festucce, when compared with the characteristic 

 gamma (y) marks of P. iota and P. pulchrina, give us a good idea of 

 the superficial development of these marks into metallic spots or 

 blotches. 



The variation in the hind wings of NOCTUJE is principally in the 

 direction of colour, the markings being frequently limited to a dark shade 

 and lunular mark, although these have really as much direct relation to 

 colour as to markings. The colour of the hind wings is very often the 

 outward sign of sexual dimorphism, the hind wings of the males being 

 generally paler than those of the females, the hind wings of many 

 species in the males being pure white whilst those of the females are 

 dark grey with certain modifications. The markings of the hind wings 

 of NOCTUJE then must be looked upon as generally restricted to a lunular 

 mark towards the centre of the wing and a dark shade roughly parallel 

 to the outer margin. The amount of the development of this shade is 

 frequently sexual, many species having, as has just been stated, per- 

 fectly white hind wings in the male, with this lunule and shade 

 developed in the female as in Agrotis segetum and A. lunigera ; in other 

 species the hind wings, white in the male, have in the female, not 

 only a dark band and lunule, but dark nervures, as in Cuspidia tri- 

 dens, whilst in others, the white wings of the male are replaced by 

 wholly grey ones in the female, as in Agrotis puta, A exclamationis, Viminia 

 myricce, Folia chi, Epunda lutulenta and E. nigra, whilst in A. cinerea, 

 the males only have the grey band developed, the hind wings of the 

 females being entirely grey. In A. valligera and A. ripce we get every 

 intermediate form, the hind wings of some specimens, both in males and 

 females, being white, others of both sexes having the band, others en- 

 tirely grey. In some of the Cuspidia aceris, megacephala and alni 

 and to a lesser extent tridens, the outer margin has the nervures 

 strongly black, with a series of black spots, sometimes very strongly 

 developed instead of the band. In Triphcena where the yellow colour 

 causes the lunule in some of the species as T. orbona (comes) to stand 

 out conspicuously, its absence is very noticeable. It is, of course, in 



