318 INSECT ARCHITECTURE. 



of this sort found during winter in a copse between Lewis- 

 ham and Bromley, Kent, every second or third one was fur- 

 nished with such a roof. (J. K.) 



Diving Water-Spider. 



Though spiders require atmospheric air for respiration, 

 yet one species w-ell known to naturalists is aquatic in its 

 habits, and lives not only upon the surface but below the 

 surface of the water, contriving to carry down with it a 

 sufficiency of air for the support of life during a consider- 

 able period of time. Its subaqueous nest is in fact a sort of 

 diving-bell, and constitutes a secure and most ingenious 

 habitation. This spider does not like stagnant water, but 

 prefers low running streams, canals, and ditches, w^here 

 she may often be seen, in the vicinity of London and else- 

 where, living in her diving-bell, which shiiies through the 

 water like a little globe of silver : her singular economy 

 w^as first, we believe, described by Clerck,* L. M. de Lig- 

 nac,"!* and De Geer. 



" The shining appearance," says Clerck, " proceeds either 

 from an inflated globule surrounding the abdomen, or from 

 the space between the body and the water. The spider, 

 when wishing to inhale the air, rises to the surface, with 

 its body still submersed, and only the part containing 

 the spinneret rising just to the surface, when it briskly 

 opens and moves its four teats. A thick coat of hair 

 keeps the water from approaching or wetting the abdomen. 

 It comes up for air about four times an hour or oftener, 

 though I have good reason to suppose it can continue with- 

 out it for several days together. 



" I found in the middle of May one male and ten females, 

 which I put into a glass filled with water, where they 

 lived together very quietly for eight dsijs. I put some 

 duck -weed (^Lemna) into the glass to afi'ord them shelter, 

 and the females began to stretch diagonal threads in a con- 

 fused manner from it to the sides of the glass about half- 



* Aranei Suecici, Stockholm, 1757. 



t ^Mera, des Araigu. Aquat., 12mo. Paris, 1799. 



