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 Caponiidoe, the chief peculiarity of 
which is the transformation of the front pair of lung-sacs into tubular trachea?— 
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 
b 
HOUSE SPIDERS, 
a, Male ; b, Female (liat. 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 Agcdenidce, 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 Drassidai 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, 
