Morley : Notes on Lepidopteroiis Variation. 51 



shining black, and the area beyond the reniform suffused black 

 and dark brown, very slightly dashed with dirty pink. The 

 exception has the pinkish colour rather more prominent than 

 the rest, and probably a near form to Mr. Ash's 3 and 4. It is 

 worthy of note that we have this very distinct variation in 

 A. ao-athina, but perhaps the strangest feature is the respective 

 variation of this species and Acrouycta menyanthidis in the two 

 districts. In the Selby district A. menyanthidis is taken 

 commonly of a black form, and A. agathina of the forms 

 mentioned above, while on the West Riding moors exactly the 

 opposite seems to be the case in both species. Such instances 

 rather upset one's calculations as to the why and wherefore of 

 local variations. It is evident, much that is now only slightly 

 understood, will have to be grasped more fully, and perhaps 

 causes that are really very effective in their influence on the 

 colours of many species are not understood, or even suspected. 

 Much remains to be demonstrated therefore before a plausible 

 solution is arrived at. 



Another species has afforded much interest in this district of 

 recent years, namely, Xylophasia polyodon. Always an abundant 

 species, and forcing itself upon one's notice so much by coming 

 to ' sugar ' so freely. It is six or seven years since I noticed 

 the first black one, but since then every 3'ear the black ones 

 have been more in evidence. During last season it may be said 

 to have been quite common. Sixteen were brought home 

 considered fit for cabinet specimens, including a very inky 

 black one, and as many were left on account of their shabby 

 condition. Intermediate forms are common, in fact the species 

 here is a very variable one. But melanism is no doubt 

 developing very rapidly, in this immediate locality, at any rate 

 in this species. Snie/inthus populi is also worthy of note, a few 

 bred last season from larvae, found close to my home, were a 

 \ery variable and fine series. All are of types lighter than the 

 ordinary dull slat}' form. Two in particular are very beautiful, 

 with a ground colour of a light slaty hue, and striped b}- marks 

 almost white. A few have the stripes and shaded portions 

 of the wings distinctly purple, others olive green, while 

 others are the pale and faded form. The whole series is a 

 demonstration of striking variation, and give one the feeling 

 that even our most common species are well worth care and 

 attention, for it does afford much pleasure when one sees the 

 beautiful variable ranges which so many of them give, standing 

 out in such fine contrast to each other. 



1906 February i. 



