228 



WEB-SPIDERS 



uncommonly under stones in damp places, may be recognised by the coral-red 

 colour of its carapace, its bright yellow legs and pale grey abdomen. It makes 

 no snare, merely constructing a small silken case, which serves as a protection 

 to the mother and her eggs at the breeding-season. Segestria, on the contrary, 

 is much darker coloured, with a band of diamond-shaped spots upon the upper 

 side of the abdomen. It spins in holes in old walls a tubular nest, from whose 

 aperture threads which serve to intercept prey pass to surrounding objects. In 

 addition to these forms — which belong to the family Dysderidce — this tribe con- 

 tains the family Oonopidce, comprising small, slender-legged spiders, with a short 

 and high carapace, and the exotic family Coponiidcv, the chief peculiarity of 

 which is the transformation of the front pair of lung-sacs into tubular tracheae — 

 a character in which this family is unique amongst spiders. The Filitelarice 

 contain the family Filistatidce and genus Filistata ; the latter being represented 

 by several species, none of which are British. They are small or medium-sized 



\^ ; .,^, r ..., v V^/V v.^\. , ; '■' ■ Mffl^^'llfifiW/i: 



m ; 



-boG v 



yy^,.^^:,: 



HOUSE SPIDERS. 



a, Male ; b, Female (nat. size) ; arrangement of eyes shown on left hand of figure, 



species, easily recognised by the aggregation of the eight eyes upon a tubercle 

 placed near the front border of the carapace^ and of sedentary habits, spinning an 

 extended web of white silk, in the form of an ill-defined tube. 



To the Tubitelarice are referred a number of families, presenting great 

 variation both in structural features and instincts. The Drassidce, for instance, 

 spin no snare, but merely fabricate a silken case for themselves and young at the 

 breeding-season, while others, like the Agalen idee, which include the house spider 

 (Tegenaria atrica), build a flat, sheet-like web, continuous at one extremity with a 

 tubular retreat in which the spider lurks. The spiders of this last group which 

 spin these sheet-like snares are furnished with three claws on each foot, and long 

 posterior spinning mammillae ; whereas the Drassidce and Clubionidce, which live 

 under stones, make no snare, and catch prey by chase or by lying in wait, have all 

 the spinning mammillae short, and only two claws on the feet. The above families 

 differ from the preceding tribes of Arachnomorphce in that the < stigmata of the 

 posterior pair of breathing-organs are not only united in the middle line to form 

 a single aperture, but this has also, as a rule, moved to the end of the abdomen in 

 front of the spinning mammillae. In two of the families, however, these apertures, 



