52 
SATYRIDAE 
is on the wing during the latter half of June and throughout 
the greater part of July. 
Egg Laying. The eggs are laid singly on mat grass (Nardus 
stricta ), which apparently is the only food plant of the larva 
in a state of nature, but in captivity it will feed on other 
grasses such as Poa annua , Festuca ovina, and Aim firaecox . 
When feeding on soft grasses, P. annua and others, it feeds on the 
sides of the blades, but with the hard rush-like species, Nardus , 
Festuca and allied species, it eats away the tips of the blades 
and always starts on the extreme tip, taking slow and deliberate 
bites as though biting it through with some difficulty. 
Egg. The egg stands erect and is rather less than i mm. 
high, of an oblong shape, rather fuller below the middle, the 
crown being flattened and the base rounded. It has from 
eighteen to twenty longitudinal keels, some start just below 
the crown, where they form a ridge; the surface between the 
keels is very finely ribbed transversely. The whole structure 
is irregular and asymmetrical. When first laid, the colour 
is a bright clear yellow, gradually becoming rather duller ; 
on the fourth day it is blotched and speckled with pale reddish- 
brown, which afterwards turns to rust-red ; finally the young 
larva shows clearly through the transparent shell and hatches 
on the eighteenth day. 
Larva. Upon hatching, the little larva eats away the crown 
of the egg and emerges; it then immediately starts feeding 
on the empty shell, its first meal. Most of the larvae hatch 
from the egg towards the end of July. 
Hibernation. E . epiphron passes hibernation in the larval 
state. It enters into hibernation in September, usually during 
the last ten days, and passes through an unbroken spell of 
torpidity lasting about five months. Early in March it awakens 
from its winter's sleep and when the temperature is sufficiently 
warm it feeds by day. After its third moult, the larva becomes 
fully grown, when it is 19 mm. long. The head is green and 
globular, roughly granular and sprinkled with minute whitish 
bristles ; the mouth parts and eye spots, brown and ochreous. 
The body is fuciform, the anal segment terminates in a pair 
of points similar to those of the Small Heath in structure but 
dull ochreous instead of pink. 
The ground colour is grass-green, with a darker green 
