r28 LEPIDOPTERA. 



become one broad irregular longitudinal stripe. Another and 

 quite independent phase of variation is in the breadth and 

 shape of the marginal blue stripe of the hind wings. This, 

 in some cases, especially in small dark specimens, is extremely- 

 broad round the apex and along the hind margin, sometimes 

 extending into the wing in a broad indentation in the middle 

 or near to the anal angle. A third direction of variation is in 

 colour; occasionally, though rarely, a specimen is taken in 

 which the spots and hind wings are of a reddish-yellow — one 

 such is before me, taken by Mr. W. Holland near Reading — 

 or the hind wings are shaded with orange. In other cases, 

 also hitherto very rare, the spots and hind wings are clear 

 yellow. A startling instance of this has occurred in the 

 present summer, an isolated colony having been found by 

 Mr. W. M. Christy in West Sussex, of wliich very many 

 specimens were of a clear pale yellow, some having also the 

 spots united in pairs, and one in which all were joined into a 

 blotch running three-fourths the length of the fore wings. 

 With these were found some red specimens with the spots 

 abnormally small ; and others in which the wings were 

 incomplete, as though irregularly cut back, so that some 

 had but half wings, and a few were nearly apterous. Mr. 

 S. Stevens has two specimens in which the fore wings are 

 entirely suffused with red except along the dorsal and hind 

 margins. Dr. Mason has beautiful yellow specimens with and 

 without confluent spots similar to those just mentioned. A 

 much more perplexing variation occurs now and then in a 

 specimen showing a more or less distinct sixth spot. I have 

 taken one such in Pembrokeshire in a secluded locality in 

 which the present species abounded, but in which I never saw 

 any allied species. 



On the wing in June, and, in its more northern range, in 

 July. 



Larva one inch long, very plump, with segments deeply 

 divided. Head small, black ; body rich yellow-green or 



