THE AUSTRALIAN NATURALIST. 37 
a quarter of an inch away. It was now shorter and 
thicker than before. It then fastened itself at each end 
by a series of rope-like threads, and by moving its head 
backwards and forwards, proceeded to spin a cocoon of 
coarse threads. At 9 a.m. next morning the head was 
curved under the body, moving backward and forward, 
and at 11 a.m. it lay quite still. 
There were thin patches on the cocoon where the 
threads were not*so densely woven, and as the pupa be- 
came black on hardening, the dark surface showing 
through the thin spots of the white cocoon gave the mot- 
tled appearance which had already been noted. 
The mature ichneumon escapes by cutting a hole at 
the end of the cocoon. The wasp hatched out in a fort- 
night. Cocoons appeared from March to May, being most 
plentiful in April. 
The caterpillars which escaped being parasitised in 
their early stages were not subsequently attacked; a 
dozen which I kept under observation all pupated in due 
course. 
A PARASITE OF EUMENES, A MASON WASP. 
(By Mabel N. Brewster.) 
The mud cells of the wasp were completed towards 
the end of November, 1917. Several adults hatched out 
in December, and one early in January. Two of the cells 
each contained a dark cylindrical cocoon, which was kept 
under observation, and in March, 1918, an adult Bombylid 
fly hatched out. 
The mud cells had been broken, so the wasps had no 
difficulty in escaping. The pupal shell was seen to have 
a set of strong spines at the apex and two large stout 
ones on each side, the whole making a formidable weapon 
adapted for cutting a way out of the mud cell. The 
back is armed with rows of short vertical bars, having a 
short stout spine at each end. ‘These are probably ‘to 
enable the pupa to move along as it emerges. Between 
each bar of spines on the back is a very long orange- 
coloured hair, thus forming rows of hairs. The pupal 
shell had the top row of hairs attached to a -number of 
