PsOCID^. INSECTS. PXEKONAKCYS. 249 
Family — PERLID.®. 
caused by White ants in Ceylon. Here follows a pas- 
sage — * 
“ I was one forenoon sitting in a large drawing-room 
with two ladies and two other gentlemen, conversing 
upon the usual topics of the day ; when suddenly we 
heard a very extraordinary and loud noise over head, 
which greatly startled us; for, immediately after, the 
whole of the roof of the large old Dutch house, strange 
to say, fell all around us ! — and there to our amazement, 
w’e sat uninjured; the bright sky above us, and an 
immense mass of rubbish piled up about us, over w'hich, 
it maybe well supposed, we lost no time in scrambling. 
All the furniture in the several rooms w'as completely 
buried under large broken tiles, woodwork, &c. ; from 
which arose a dense and suffocating cloud of dust. The 
reader may easily imagine what a wonderful escape we 
all must have had; for, if the immense quantity of 
materials had fallen upon, in place of around us, we 
must inevitably have been crushed to atoms under 
them. The servants, also, from being at the moment in 
the go-downs or offices were uninjured ; but the sister- 
in-law of the chief justice had a narrow escape ; for she, 
her palanquin bearers, and the Lascareens, who were in 
attendance upon her, had just got clear of the large 
verandah in front of the house, when the roof fell, 
chiefly in it ; and with such a tremendous crash that it 
was heard distinctly all over Colombo. So loud was it, 
indeed, that crowds of people ran from all quarters, in 
order to ascertain what could have been the cause of 
such a commotion ; many imagining that the sea — as it 
is said to have done many years before — had again 
broken into the Fortress. On examining the old mate- 
rials of the building, it appeared that almost the whole 
of the large beams and other woodwork though they 
looked perfectly sound outside, had been hollowed out 
by those unseen, but most persevering under-cover 
labourers, the White ants !” 
In Europe there is but one Termes whose ravages 
ever attract notice. The archives of the Prefectures 
and Arsenal of La Rochelle have been nearly quite 
destroyed by them, whilst the woodwork of the rooms 
was reduced to powder. Ants were introduced, but 
their meeting was worse than “Greek meeting Greek;” 
the ants were soon exterminated by the powerful jaws 
of the Termites, who literally cut them in two. Pow- 
dered arsenic and chlorine have been used with success 
in reducing their numbers. 
Family— PSOCID^. 
A family of small insects, with the labial palj)i almost 
wanting. The antennae are long and composed of thir- 
teen joints or so. These insects are found on the trunks 
of trees, stones covered with lichens, old books, &c., 
and not only they, but both the larvae and pupae, are 
very active. 
The Atropos puhatorius is often very destructive to 
books kept in damp places and to collections of natural 
history. It is an apterous and a minute pale insect. 
* I have not by me Sir J. Emerson Tennent’s admirable work 
on Ceylon, otherwise I would have preferred quoting from the 
pages of that graphic author. 
Von. II. 88 
By some authors these aquatic insects are placed 
with the Orthoptera. They have an oblong, depressed 
body. The males are generally smaller than the females, 
and have short wings ; whilst in the females the wings 
are large and looselj' veined. It is in their larva and 
pupa states that these insects live in the water. Mr. 
Newman has made a study of the British species, and 
has described many of the North American and other 
exotic species. 
Mr. Barnston made several valuable observations on 
the transformations of Perlidae at St. Martin’s Falls, 
Albany river. Newport has published some of these 
observations, which show that they undergo their trans- 
formations, and even pair, at very low temperatures. 
One species, the Capnia vernalis, comes forth at the 
end of winter when the thick ice begins to crack, and 
changes from the nymph to the perfect state in the 
crevices, leaving its slough there even when the tem- 
perature of the air has sunk to freezing. Another 
species, Bradiyptera gladalis, makes its appearance 
at that time, undergoing its changes, and even pairing, 
in the crevices of decaying ice. These insects are 
short-lived in their perfect state, so that, although pair- 
ing takes place at but little above the temperature of 
freezing, the ova are deposited at a time when the 
diurnal warmth is increasing, because accessions of 
force from without are necessary to evolve vital force 
within them, and induce the formation of structure.* 
Pteronarcys.— This 
is a genus of Perlidse 
peculiar to North Amer- 
ica. It was established 
by Mr. Newman, who 
described several species 
— one of the largest is 
the Pteronarcys regalis^ 
a Canadian water fly, 
nearly four inches across 
when its wings are spread 
out. Its pupa is here 
figured. 
This insect, as de- 
scribed b}' Mr. Barnston, 
comes abroad only at 
dew-fall or in the night, 
and when on the wing it 
is constantly dipping on 
the surface of the water, t 
Mr. Doubleday, who 
took it at Trenton Falls, 
found it chiefly on wet 
evenings and during the 
day. He says that it hides itself in crevices of the rock 
which are constantly wetted by the spray of falling water, 
under stones, and in other damp places. Mr. New- 
port found that the Pteronarcys possessed branchiae, or 
traces of branchiae, in the perfect siate. He says that 
* Newport Ann. and Mag., November, 1850. 
f Newport on the Analogy and Affinities of Pteronarcys 
regalis. Linn. Trans., vol. xx. p. 432. 
Pupa of Pteronarcys regalis. 
