12 NYSSIA LAPPONARIA. 
finely raised ridges. The colour is of a very clear 
bright greenish-yellow ; a few days before hatching it 
deepens in colour, and gradually becomes deeper until, 
shortly before hatching, it assumes a very deep 
metallic blue-green hue. The ova hatched between 
5 and 6 p.m. on the 16th May. 
Directly after emergence the larva measures one- 
twelfth of an mech while extended ; if disturbed it 
falls, suspending itself by a web; and if falling upon 
the ground, remains for a short time in a looped 
attitude. 
The larva in its first stage and when ten days old 
is one-sixth of an inch long, cylindrical, and of uniform 
thickness throughout; the ground colour is a deep 
dull black; the first segment has the anterior edge 
white, forming a collar and encircling the segment. 
Immediately behind the collar is a series of very 
minute warts, each beset with a short fine bristle. 
The fourth, fifth, sixth, seventh, and eighth segments 
are each encircled with a number of pure white 
markings, consisting of fourteen on each segment 
(seven on either side) ; the dorsal pair are longest, and 
are separated by a medio-dorsal black line. These, as 
well as the two largest lateral spots and the lowest 
ventral one, have each a black central wart emitting a 
short whitish bristle; the second, third, ninth, tenth, 
eleventh, and twelfth segments are principally spotted | 
on the lateral region. ‘The head is black, with white 
spots at the mouth. The legs and claspers are black. 
During the first stage the larvee fed upon both birch 
and whitethorn, and appeared to prefer the latter if 
one more than the other. The first moult occurred 
on 31st May. 
Before the second moult, twenty-one days old, it 
measures three-tenths of an inch in length; the 
ground colour is llac-brown, with fine white longi- 
tudinal lines running the entire length, which are 
dorsal, subdorsal, superspiracular, and subspiracular. 
On the fourth, fifth, sixth, seventh, and eighth 
