THE PALE CLOUDED YELLOW 
327 
some specimens a remarkable aberration occurs ; this has a 
conspicuous black spot immediately below the spiracular line, 
precisely similar to that in C. croccus. In some these spots occur 
from the third to the eleventh segments inclusive, in others 
they are only on a few segments, while others have no trace 
of them. 
There is a remarkable similarity between the larvae of 
C. hyalc and that of C. croccus. The chief difference is that 
C. hyalc lacks the fine, whitish pubescence which covers 
C. croccus. Also, the eggs of both species greatly resemble 
each other, but the spaces between the keels are flat in C. hyalc 
and concave in C. croccus. Also the 
transverse ribs number about forty- 
six in the former, instead of thirty- 
six in the latter. The colour is 
paler in C. hyalc , especially at the 
ends. The larval stage of the sum¬ 
mer brood occupies thirty days, of 
the autumnal brood, which hiber¬ 
nates, about 250 days. 
Pupa. The length of the pupa 
varies from 20*50 mm. to 22*20 mm 
The head terminates in a short, 
straight beak ; the thorax is humped 
dorsally ; the abdomen rounded and 
tapering to the anal point ; the wings 
are ample, rounded, and swollen in 
the middle. The whole of the dorsal 
surface varies from pale green to light greenish-yellow, in 
some specimens it is decidedly yellow ; the wings are darker 
green. The ventral surface of the abdomen is the same 
colour as the dorsal surface. Along the side of the abdomen 
are three minute black dots, and below these a dark purplish- 
brown band, composed of four oblong markings, one on each 
segment. On the wing is a sub-hind-marginal series of six 
black dots, each separate dot situated between the nervures, 
and a central black discoidal spot. 
The pupa is attached to the stem of a plant by a silken 
cincture round the middle and by the cremastral hooks to a 
pad of silk. The pupal stage lasts seventeen days. 
Segment of larva of the 
Pale Clouded Yellow, hiber¬ 
nating stage, after third 
moult. 
