60 



The upperside is of a deep dark blue, with black hind-margins, and granu- 

 lated with black scales, giving it a dull appearance. There is a black central 

 spot on the fore- wing, and four spots or more between it and the hind- 

 margin. The female differs from the male by having the spots of a larger size, 

 and wedge shape, instead of being round as are those of the male. The 

 underside is of silvery gray with a blue tinge near the base of the wings, 

 and has many black spots in white rings. 



The expansion of the wings varies from one inch and five lines, to one inch 

 and eight lines. 



Yar. b. (Alcon, Steph.) is of a brownish ash colour on the underside, and 

 has the spots rather indistinct. Stephens records it as being in the collection 

 of Mr. Haworth, and that it was captured in Buckinghamshire, by Mr. Jones, 

 known by his paper on the neuration of the wings of the Linnsean Papilions. 

 After Mr. Haworth's death, it was bought at the sale of his effects, by Mr. 

 Dale. Other examples exist in various other collections. 



Another variety, Cyanecula, occurs in North-Eastern Siberia. 



The egg is round, smooth, and depressed on the top, and of a pale greenish- 

 blue colour. It is covered with fine raised transparent white reticulation. 



The caterpillar is a stout little fellow, but tapering towards the head. At 

 first it is of a dull green colour, but afterwards turns to a pinkish-brown, the 

 body being sparingly clothed with light brown hair. When young it feeds 

 on the flowers of Thymus serpyllum, but in captivity always dies before chang- 

 ing to a chrysalis. 



Arion is generally distributed over Europe, and the North and West of 

 Asia. In Germany it haunts the lofty fir forests, where the ground is clothed 

 with bilberry, moss, and straggling plants of wild thyme, and is to be met 

 with throughout the month of July. In Silesia, though, Professor Zeller 

 found it plentifully in the moist open meadows at the foot of Mount Hoch- 

 wald. It has never been met with in Ireland, Scotland, or the Isle of Man, 

 and in very few counties in England. 



Donovan in his "Natural History of British Insects," published in 1796, 

 writes, " Papilio arion is a very scarce insect in this country, and it does not 

 appear to be much more common in any other part of Europe, as Eabricius 

 only says " Habitat in Europee Pratis. Mr. Lemon, a collector of eminence 

 some years since, met with it in England." 



British specimens of Arion belonged to the celebrated Duchess of Portland, 

 and after her death, were sold at the sale of her Museum, in 1786. 



In his "History of British Insects," 1795, Lewin writes, "This species 

 of butterfly is but rarely met with in Engla d. It is out on the wing the 

 middle of July, on- high chalky lands in different parts of the kingdom, 



