68 
type, solved the difficulty and prevented dessication by burrowing into 
the interior of a leaf, and living among its juices. 
If a larva of Phyllocnistis be taken from its mine and exposed to 
t e an, it will dry up in a very short time. Buccalatrix perhaps, in its 
early stages, one of the smallest exposed feeders, encloses itself in a 
kind of cocoon while changing its skin, in order, I would suggest, to 
prevent dessication. Even Colenpkora, a very much larger larva, 
undeigoes its first ecdysis within the mine. Small larvae, like those 
of the genus Aryyrest/na, keep themselves moist by burrowing into 
shoots and buds, while a similar burrowing habit is prevalent among 
the much larger larvie of the Tartricids. Although larvae which 
buriow into stems, shoots, and leaf buds may be hidden, and therefore 
moie or less protected from their enemies, I do not believe the leaf- 
mining habit was resorted to primarily for the purpose of protection 
from living enemies. No doubt this protection has had a good deal to 
do with the lines on which this habit has developed. The leading 
idea was to ensure a moist condition for these minute creatures, and, 
after this moist condition was attained, the secondary idea of protection 
began to work its modifying influences on the character of the nimes. 
SUPPLEMENTARY NOTES ON CIDARIA. * 
(Read November 19th, 1901. by LOUIS B. PROUT.) 
When 1 read a paper on this genus in April last, 1 found it 
necessary to allude to various lacunae, and I expressed the hope of 
being able to fill up some, at least, of these in the near future. As I 
have to some extent succeeded in realising this hope during last 
summer, I think it well to bring before you the following supplementary 
notes. They deal with the type-species of Pyyris, Hb., riz., populatei, 
Linn., and two of the outlying species, silaceata, Hb., and pyraliata, 
Schiffi, all of which I have had under observation from egg to pupa 
during the last summer. 
Lygris populata, Linn.—The larvae which were just hatching when 
I wrote in April, were fed chiefly on lombardy poplar {Papula* 
pyramid alia), as bilberry was unfortunately not obtainable. Notwith¬ 
standing the “ Habitat in Papula'' of Linne’s original description of 
the species, I did not find they throve very well on this food, and I only 
got one or two as far as the pupa stage, and these were undersized. 
Occasionally Salix alba was offered, and this seemed to give somewhat 
better satisfaction than the poplar. The duration of the larval period 
was about seven weeks—April 10th to June 2nd. I made copious 
* Publication accidentally delayed. 
