96 
Dr. T. A. on Callophrys avis. 
larva attains 12'0 nun. when stretched in walking with head ex¬ 
tended ; the width about 3'0 mm., and of head about 0’6 mm. Tlie 
head black, except where the vertex is usually within prothorax, 
labruni whitish. The rest of the larva is wholly of a transparent 
green, except a very narrow lateral line, yellow, and the prothoraeic 
plate of a purplish pink, with a faint pale median line. The s])iracles 
are darker dot.®, apj)arently very narrow rings of deep brown. 
When about to moult the larva spins a few threads to surrounding 
leaves as well as a silken pad. 
In the last instar when full grown (Plates XV, XVII, XVIII) the 
larva Avhen active attains a length of about 20 mm., but when resting 
or sulky only some 15 or 16 mm., but is then some 5'5 mm. wide, and 
5 mm. high; short and thick, thickest about first and second 
abdominal segments. 
The larva is of a uniform transparent green, with a yellow lateral 
line and a brilliant red (purplish pink) prothoraeic plate. The 
depression of the prothoraeic plate is conspicuous, lying deeply 
under mesothorax with the front of the prothorax rising above it. 
The broad red stri})e across the prothorax, and the uniformity of 
all the larvae in the light transparent green colour, broken only by 
the plate and by the thin lateral line, render the larvae conspicuously 
different from any other I have seen. 
The red stripe is like nearly all colouring in Lycaenid larva, a 
little way below the cuticle, and though one supposes at first it is a 
colouring of the prothoraeic plate, this is not so, as it e.xtends widely 
to each side beyond the plate, almost right across the prothorax. 
Oidy one larva varies from this, in having a broad lateral rusty red 
band, obscuring the yellow lateral line, which seems deeply buried, 
but has some of the rusty tinting at the incisions. The rusty tint 
is superficial and involves the whole flange practically up to the 
spiracles. The prothorax is ruddy tinted and there is a slight tint 
on the dorsum of the seventh abdominal segment. 
I copy tlie above as it appears in my notes, but furtlier 
notes show that this larva was in the first stage of the 
change of colour that is undergone when the larva is pre¬ 
paring to search for a pjlace for jrupation. 
The larva never goes anywhere without making a silken 
path and often quite a pad, on the leaf it is eating. When 
recently moulted into the last instar, there is quite a 
ruddy halo due to the closeness of the reddish hairs. 
When the larva is full-fed the hairs become so far separated 
as to be hardl}^ visible. 
On June 7th, I noted that on each of the past three 
