190 BRITISH LEPIDOPTERA. 



perhaps on the upper side almost hollowed, consequently the 

 widest part of the egg here (romm.) is only one-fourth from the top; at 

 the nadir it is only o-8mm. at about the same distance from the end. 

 The egg has a beautiful arrangement of markings, white (porcellanous 

 and opaque) on a darker ground (thinner and more transparent). 

 The details appear to vary a little on different eggs. The top 

 (micropylar end) is white, except a small circular micropylar area. 

 Calling one edge dorsal and one ventral (arbitrarily and for con- 

 venience), two white lines leave the top and proceed down each 

 side of the dorsum, and, before quite reaching the end, curve 

 round the side and meet in front. Ventrally, the white top is 

 produced downwards so as to include a transverse pale strip, and 

 about the middle is again a transverse white strip. On each side 

 is a circle, or rather ellipse, of not so pronounced white, forming 

 a sort of centre, round which the white dorsal lines curl concentri- 

 cally. The micropylar area is about o'^mm. in diameter, and in 

 this width there are about 1 1 cells, i.e., roughly 6 circles of 

 hexagonal cells occupy the area, the smallest centrally. The central 

 ones are placed in a rosette of 8, and have a stellate set of lines 

 at the micropyle (result of egg being old and cells parting from 

 each other?). Outside this area no cells can be made out, but 

 there are a number of fine dots that appear to be placed at the 

 angles of a set of (invisible) hexagonal cells, often tolerably 

 regular, and varying in size from o*o2mm. to o-c^mm. in diameter. 

 Under a higher magnification these dots or points appear to be 

 really very fine hair-like points (Chapman). Ochsenheimer says : 

 " The eggs are longish oval in outline, white, marked with brown, 

 above with a black spot." De Geer describes them as being of 

 the form of small elongated bowls, white, with some brown spots ; 

 a black point at one of the ends. 



Habits of larva. — Stainton repeats Ochsenheimer's observa- 

 tion, that, "at Leipzig, the larva? and cocoons are brought in hundreds 

 almost every year, for sale, to the market, by the country people who 

 gather bilberries." Freer writes {Ent., xvi., p. 260) that he found three 

 larvae in 1879 and two in 1883 on Cannock Chase, that they were 

 difficult to find, reposing in the daytime on twigs of heather, pre- 

 ferring dead or old twigs ; he suspects that they feed at night, as he 

 never found any feeding or even resting on their foodplant, Vaccin- 

 turn myrtillus. Hering states that, in Stettin, lie found the full-grown 

 larvae resting low down on aspen. De Geer writes (JA'y//., i., pp. 229 

 et seq.) : 'The larvae are heavy and slow, walking little, the body 

 supple and flaccid as are those of the 'lackey' larvae. Sometimes 

 the larva takes up a very remarkable attitude, rolling itself into a 

 circle with the legs and venter outside, occasionally the larva only 

 raises the anterior part of the body, and folds it back, resting often 

 more than a quarter of an hour in this position, at other times it will 

 bend the front of the body back so that the head touches the 8th or 

 9th segment, and, as the larva at the same time maintains its hold by its 

 prolegs, it appears as if the body were bent in two." 



Larva. — Adult (from blown example). Length t'6ins., diameter 

 at widest segment (5th abdominal) ■151ns. Superficially the larva 

 reminds one of a dull or rather brownish larva of Cosmotricht 

 potatoria, Head: Rounded, only slight tendency to square or 



