76 TRAP-DOOR SPIDERS. 



their falces,* which have the fang directed downwards, 

 and move vertically parallel to one another. Thus 

 when a victim is seized by one of the Territelarits it 

 receives a downward blow, while other sjjiders strike 

 sideways, the falces moving in a horizontal or oblique 

 direction. With very few excej^tions this sub-order 

 may also be known by the presence of four blotches 

 of paler colour at the base of the abdomen underneath, 

 indicating the position of four air-sacs, almost all, or 

 indeed perhaps all, other spiders having but two. 



Certain species of TerritelaricB are the only spiders 

 known to construct nests closed with a door, and these 

 creatures must be admitted to rank among the first 

 of Nature's handicraftsmen and inventors. 



The geometrical webs of many common spiders 

 are very beautiful structures, but these are for the 

 most part only snares for prey, and not permanent 

 dwellings, although the cocoons in which the eggs 

 are placed are often most ingeniously contrived. Thus 

 in the south we may sometimes find an inverted bal- 

 loon of strong silk about an inch long attached to 

 heath and other bushes, which, if examined during 

 the winter, will be found to contain in its centre a 

 case enclosing a mass of eggs about one-third the bulk 

 of the entire cocoon. This inner case is shaped ex- 

 actly like the outer, and both have a circular silk lid 

 carefully closed, and the space between the two is 

 filled with a dense mass of golden-brown silk, which 

 acts no doubt as an excellent non-conductor. This 

 cocoon is the work of Epeira fasclata, a species ap- 

 parently only found in southern Europe. 



* Sometimes called mandibles. One of these is rei^resented, enlarged, at 

 Fig, A 7. in Plate VII., p. 88. 



