vol. xiv, p. 220, pi. I, figs. 12, 13). I learn from Mr. McArthur, who 

 has had a very considerable experience of this form in its native 

 haunts, that its usual and almost only resting-place is on rocks, its 

 peculiar shade harmonising so closely with their grey colour as to 

 make it exceedingly difficult to find, especially as it usually rests on 

 the parts of the rocks that are in shade. 



On the Scottish mainland we find a greater range of variation, the 

 brown tints entering pretty generally into the composition of the 

 wing pattern, but the insects are often, particularly on the higher 

 grounds, but not always, somewhat undersized and slender as com- 

 pared with the average of our southern examples. There is one 

 form, however, to which I would call special attention. The series 

 representing it was brought from Aviemore (Inverness) last year by 

 Mr. McArthur. In tone of colour the specimens are almost as 

 completely grey as the Isle of Lewis examples, but of a softer, 

 warmer tone and less distinctly mottled (PI. I, fig. i). They were 

 all taken at from 900 to 1000 feet up the hills in the pine forest, 

 where the trees are of all ages up to probably some hundreds of 

 years old, their stems are of all colours, from the dark bark of the 

 comparatively young ones to the grey lichen-covered patriarchs of 

 the forest, but such moths as did rest upon them did not appear to 

 show any preference for the one or the other, and were so restless 

 that very few indeed were taken from such positions, nor were there 

 any rocks in this locality for them to rest upon, and, indeed, the 

 species appeared to have developed a special habit ; perhaps it will 

 be best described in Mr. McArthur's own words, as follows : " ^Vhen 

 the woodmen cut the timber they draw only the trunks ; the tops 

 and branches are left in heaps to rot, which takes many years. In 

 course of time these heaps get very bleached. It is in these that 

 repandaia is very fond of hiding, and it was by tapping these heaps 

 that I got nearly all of them." It will be noted that these heaps are 

 purely artificial, and may or may not have existed for any lengthened 

 period. In these circumstances one cannot suppose that the insect 

 has adapted its tone of colour to them, but it may suggest that the 

 moth has taken advantage of their presence, and in course of time 

 acquired the habit of seeking the shelter and protection that they 

 afford. 



Such series as I have from the Isle of Man and from North ^Vales 

 call for no very special remark ; both show an amount of variation 

 within certain lines, but do not exhibit any very extreme forms. 



In Yorkshire the most notable form is a melanic race which 

 occurs in the Huddersfield district. In it the brown shades are 

 replaced by smoky black, which in extreme cases, especially in 

 the females, almost completely obscures the usual markings ; but in 

 some of the forms, more particularly in the males, the pale grey, sub- 

 marginal wavy lines stand out in strong relief, and there is also a 

 certain amount of grey mottling, most prominent on the hind-wings 

 (PI. I, fig. 2). This melanic form appears to be the one described 



