HABITATIONS OF INSECTS. 473 



is not at all used as a snare, but merely as a safe abode 

 fertile spider, which hunts its prey at night only; and, 

 when caught, devours it in security at the bottom of its 

 den, which is generally strewed with the remains of 

 coleopterous insects''. — From some curious observa- 

 tions of M. Dorthes on this species in tJse second vo- 

 lume of the Linnean Transactions, it appears that both 

 the male and female spider and as many as thirty young 

 ones occasionally inhabit one of these galleries. — Ara- 

 nea Sauvagesii of Rossi, which is a distinct species 

 found in Corsica, forms a similar habitation*'. 



The galleries just described are the work of an Eu- 

 ropean species not uncommon in the south of France ; 

 but similar ones are fabricated by Aranea retuitoria, an 

 inhabitant of the West India islands, as well as by 

 many other tropical species. I have seen one of these, 

 which had been dug out of the earth, in the cabinet of 

 Thomas Hall, Esq. F.L/.S., that was nearly a foot in 

 length and above an inch in diameter, forming a cylin- 

 drical bag of dark-coloured silk, closed at the bottom, 

 and accurately fitted at the top by a door or lid. 



The habitation of Aranea aquatica, the other spider 

 to which I alluded, is chiefly remarkable for the ele- 

 ment in which it is constructed and the materials that 

 compose it. It is built in the midst of water, and 

 formed, in fact, of air ! Spiders are usually terrestrial, 

 but this is aquatic, or rather amphibious ; for though 

 she resides in the midst of water, in which she swims 

 with great celerity, sometimes on her belly but more 

 frequently on her back, and is an admirable diver, she 



"" Sauvages Hist de. VAcad. des Sc. de Paris 1758, p. 26. 

 " Lcatr. Jlist. Nat. vii. 165. 



