BRITISH SPIDERS. 77 



CASE favourable circumstances,) it is probably the cause of the colour 

 of the web, and perhaps also of its clinging so closely to whatever 

 it touches. 



No. 20. Amaurobius mordax (Ciniflo mordax, i5/.).— 20. Enlarged sketch. 

 Fawn-coloured ; about half an inch in size. 



No. 21. Agelena labyrinthica. {Clerck.)—'2X. Enlarged sketch. 



Agelena labyrinthica, female (slightly magnified). 



Brown, with a paler herring-bone pattern on the back of the 

 abdomen. 



The specific name of this species (labyrinthica) is probably 

 derived from the form of its web or nest. In autumn we often 

 see in hedges or heaths a rather considerable and thick mass of 

 white strong compact spider's web, from part of which a sort 

 of funnel or cylindrical tube runs downwards ; the mouth opens 

 wide and extends outwards usually for some distance as a simple 

 single horizontal web, but gradually narrows at the inner end 

 until it ends in a tube or tunnel large enough to admit one's 

 finger. This tube frequently opens into one or more tubular 



