On the coast of Dorsetshire a very unusual form occurs. The border of the outer margin is white instead of the usual black or blackish; the inner limit of this border is, on the fore wings, defined by a dusky shade, and the black nervules break up the border into six spots; on the hind wings four or five of the white spots are centred with black dots. The female has a similar border, but on the hind wings it is inwardly edged with orange. It has been named var. _fowleri_, and I have seen one example of this form without black dots in the marginal white spots of the hind wings. On the under side variation is on somewhat similar lines to that adverted to in the last species. On Plate 109, Fig. 8 represents the typical under side of the male, and Fig. 7 that of the female. It will be noticed that the male is greyer than the female. Some of the ordinary aberrations are shown on the same plate, and some rarer ones will be found on Plate 118, and of these Fig. 12, if without the basal spot on the fore wings, would represent var. _lucretia_. For figures of the early stages see Plate 108; that of the caterpillar is after Buckler. The egg is flat on the top, with a slightly darker pit in the centre (the micropyle); the sides are rounded, netted, and studded, and the colour whitish-green. The above short description was taken from one of a few eggs of this butterfly sent me in August last by Mr. Ovenden, and the same egg has been figured. Mr. Frohawk has described the egg more fully in the _Entomologist_ for 1900. With reference to the egg-laying of the butterfly he writes: "On August 13th, 1900, I watched several females in the act of depositing, on various stems of the usual stunted herbage to be found growing on chalk downs. They frequently crawled among the plants for a distance of about a couple of feet, occasionally curving the abdomen downwards among the small plant-stems and grasses, and here and there depositing an egg. I therefore dug up portions of the turf, potted it, and placed a couple of females on each lot; they deposited ova on the 14th and 15th, on the stems of various plants; a few were laid upon the brown dead trefoil leaves, as well as on the living leaves; but the site generally chosen is the intermingled stems of both plants and grasses. Another female, placed upon a similar pot of plants, deposited about fifty ova on September 10th, nearly all being placed upon the stems, and a few upon the under side of the leaves of rock-rose; in all cases the eggs are deposited singly." The caterpillars do not hatch out until the following spring. According to Buckler and Hellins, the only difference between the caterpillar of this butterfly and that of the next species, _Adonis_, is that the latter "has its ground colour deeper green, with the hairs or bristles black, while _Corydon_ has the ground colour of a lighter, brighter green (a green with more yellow in its composition), and the hairs light brown."