PSOCID^.- 



-raSECTS.- 



-Pteronakcys. 



249 



caused by White ants in Ceylon. Here follows a pas- 

 sage — * 



" I was one forenoon sitting in a large dramng-room 

 with two ladies and two other gentlemen, conversing 

 upon the usual topics of the day ; when suddenly we 

 heard a rerj" extraordinary and loud noise over head, 

 which greatly startled us; for, immediately after, tlie 

 whole of the roof of the large old Dutch house, strange 

 to say, fell all around us I — and there to our amazement, 

 we sat uninjured ; the briglit sliy above us, and an 

 immense mass of rubbish piled up about us, over which, 

 it maybe well supposed, we lost no time in scrambling. 

 All the furniture in the several rooms was 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 

 fiuch 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 antsF' 



In Europe there is but one Tennes whose ravages 

 ever attract notice. The archives of the Prefectures 

 and Arsenal of La Eochelle 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 stnalHnsects, with the labial palpi almost 

 wanting. The antennae are long and composed of thir- 

 teen joints or so. These insects are fpund 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 Atropns jmleatvrius is often very destructive to 

 books kept in damp places and to collections of natural 

 hiistory. It is an apterous and a minute pale insect. 



• J hare not by me Sir J. Emerson Tennent's admirable vrork 

 on Ceylon, otherwise I would have preferred ^otingfrom the 

 pages of that graphic author. 

 Vol. II. 



Family— PERLID.a;. 



By some authors these aquatic insects are placed 

 with the Ortlioptera. 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 loosely 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 Perlid® 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 tliick ice begins to crack, and 

 changes from the njTnph 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, the Brachyptera glacialis, 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 Ihe temperature of 

 freezing, the ova are deposited at a time when the 

 diurnal warmth is increasing, because accessions of 

 force from without are necesswiy to evolve vital force 

 within them, and induce the forjuation 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 by 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.'!". 



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, 

 tinder stones, and in other damp places. Mr. New- 

 port found that the Pteronarcys possessed branchiae, or 

 traces of branchia;, in the perfect state. He says that 



• Newport Ann. and Mag., November, 18.'iCK 

 \, Newport on the .Analogy and Aftinities of Pteronarcys 

 legalia. Linn. Trans., voL xx. p. 432. 



»I 



Pnp* of Pteronarcys regalis. 



