33§ 
PIERIDAE 
and claspers, is a clear yellowish-green. The whole surface 
of the head and body down to the spiracular stripe is densely 
covered with black, pedestal-shaped tubercles, each bearing 
a minute black spike. 
Throughout all its stages the larva rests on the upper 
surface of the leaf, lying in a straight position along the 
midrib, with the anal claspers fixed to the stalk at the base 
of the leaf when in its last stage. 
When it ceases feeding and is ready for pupation, it 
invariably leaves its food plant to seek some other place for 
pupating. I have frequently searched Buckthorn bushes upon 
which the larvae have fed and have failed to find the pupae 
on any part of the bushes. On two occasions I have found 
G. rhantni just emerged from the pupae, once in July, 1895, 
and again in July, 1931. Both butterflies were clinging to 
the under surface of a Bramble leaf close beside the empty 
pupa ease, which was attached to the midrib of the leaf. 
The Bramble stems were growing low down, about a foot 
above the ground amid grass stems and other rough herbage. 
In both cases the Buckthorn bushes were some distance away, 
and the positions and surroundings of both sites were iden¬ 
tical. The larval stage occupies twenty-eight days. 
Pupa. The pupa measures from 22 mm. to 23*80 mm. in 
length. The head is strongly beaked ; the thorax is concave 
with a slight dorsal keel, convex at the meta-thorax ancl 
the base of the abdomen, over which the silken cincture passes ; 
the abdomen is swollen and gradually attenuated at the 
extremity ; the wings are very curved along the costal margins, 
and the apex is pointed. The colour is a clear, bright green ; 
the beak and blotch at the base of the wing is purple ; the 
discoidal spot, the sub-spiracular, also the ventral markings 
are purplish-brown. The pupa is attached to a pad of silk, 
on a stem or leaf by the cremastral hooks, and by a fine but 
long cincture round the middle. Shortly before emergence 
the male pupa becomes very brilliant in colour, the wings 
assume a beautiful rich yellow with vermilion marginal spots, 
and the antennae become red. The pupal state lasts about 
fourteen days. 
Imago. The average expanse of the wings in the male is 
62 mm. ; in the female, 65 mm. The fore wings are curved 
