216 
WHITE LETTER HAIR STREAK. 
middle in the secondary pair, and forming two acute 
angles posteriorly, in such a manner as to resemble 
the letter W ; behind this there is an irregular band 
of orange-red, widest towards the anal angle, and 
bounded on the inner side by a black line, which is 
sometimes edged internally with white ; the margin 
itself, as well as the projecting tailed point, is black, 
sometimes tipped with white. 
The caterpillar is green, with three spots of deep 
red on each of the posterior segments of the belly, 
and a double Beries of small dots along the back. 
When about to undergo its metamorphoses it be- 
comes brown. According to some authors it feeds 
on the elm, while others mention the black thorn as 
its appropriate food. 
This insect, as already mentioned, has been de- 
scribed by most British Entomologists as the P. 
Pnmi of Linnaeus, who does not appear to have been 
acquainted with it. Of late years it has occurred 
in great plenty in some districts, but in general it 
may be accounted scarce, particularly in the northern 
parts of the kingdom. “ The boundless profusion,” 
says Mr Stephens, “ with which the hedges, for 
miles, in the vicinity of Ripley, were enlivened by 
the myriads that hovered over every flower and 
bramble blossom, last July (1828), exceeded any 
thing of the kind I ever witnessed. Some notion 
of their numbers may be formed, when I mention 
that 1 captured, without moving from the spot, 
nearly 200 specimens in less than half an hour, as 
