271 



THE ENTOMOLOGIST S RECOKb. 



Mr. Tiitt records the type form as " rare in Enf,fland," whereas I 

 record it here as bearing a fair proportion to the whole number. The 

 fact is that 1 have tried to be strictly cori-ect and honest, and have 

 not thought it right to pick out the best specimens and describe them 

 only. I have, therefore, sorted out the whole number, arranging 

 them according to description, but I think you will agree Avith me that 

 all but three or four of those ranged over the label C. lutosa are so 

 worn and torn as to be worthless for identification as to variety. In 

 fact, when fresh they may have been the type, but just as likely were 

 one of the other pale forms ; therefore Mr. Tutt, in having examined 

 only fine specimens, is probably correct. 



The species varies curiously in size, suggesting that sometimes the 

 larva did not find enough food, or perhaps even that it had tried to 

 get a living where another and more sturdy relation was settled before 

 it ; for I presume that over population may result in stunted 

 specimens — even amongst moths. There seems to be also some 

 variation in shape, some of the fore-wings being more sharply 

 pointed than others, which appear quite blunt. I have not had leisure 

 to go into this matter, but, roughly speaking, the difference is not 

 sexual, as I fancied it might be. 



I have brought to-night some extremely enlarged portraits of the 

 insect, which, although not exactly what I hoped, will yet, I think, 

 show plainly enough some of the curious variations of the marking. 



Taking the type ( '. Intosa as being of a pale grey colour, with 

 whitish nervures, we are able to trace clearly enough in the various 

 forms the growth of the darkening influence of the black scales. 



You will see in my box forms which can, 1 think, be fairly called 

 spotless in both shades. The first step towards variation seems to be 

 the development of the black dots upon light nervures in the position 

 called by 8tainton the elbowed line. These dots vary in number 

 from 1 to 10 or 11 — that is to say, there may be a black dot upon every 

 nervure, and I have one specimen with this complete series of dots. 

 Now, as a rule, the further darkening of the wing is brought about 

 by what I may perhaps be allowed to call the concentration of the 

 black scales upon the margins of the pale nervures, and I take it that 

 it is this which when more fully developed produces the effect of dark 

 longitudinal shades. These dark scales are very well shown in one 

 of the enlarged photographs, especially in that of var. ni/csicus-.siijfii.sa, 

 where the light nervures ai'e distinctly framed in black scales, which, 

 with the ochreous ground colour, produces a curiously tricolour-striped 

 appearance over the whole fore-wing. But the most strange 

 variation to my mind is the way in which these black scales some- 

 times appear to diverge from the nervures at the black spots, and, 

 running at an angle from the nervures, meet one another in mid-area, 



