TWO YOUNG NATURALISTS. 153 



the surface of the water, in order to form with this a 

 protection for the edifice. The Argyroneta being 

 covered with hairs and pubescence, air adheres to its 

 body, giving it a silvery appearance when in the 

 water, and it is thus enabled to live for some time 

 beneath the surface. Being thus provided with a 

 temporary supply of air, it constructs a web some- 

 thing like in size and shape to a thimble, secured by 

 threads to neighbouring plants. It then ascends to 



the surface, and again descending carries with it a 

 supply of air, which it discharges into the silken web, 

 and repeats this operation until this novel kind of 

 balloon is sufficiently inflated, when it takes up its 

 abode therein and makes excursions in search of prey, 

 which when captured it carries back to its subaquatic 

 balloon and devours at leisure. 



" Father de Lignac states, moreover, that he was 

 acquainted with a case that appears almost incredible, 



