The families of British spiders
Morphology. The adult spiders 1–10 mm long; decidedly plump-bodied (mainly), or slender-bodied to of medium build (in some of the males); decidedly short-legged, or with legs of medium length, or decidedly long-legged (from shorter than the body to over three times as long); with eight eyes. The eyes in two horizontal rows of 4; all clear and glassy. The maxillae longer than broad. The palpal organs of the male of complex structure and enclosed by the specialized, hollowed tarsal segment (the cymbium). The male palps without a paracymbium. The female palps with a claw. Metatarsus IV of the females without a calamistrum. Tarsal claws 3. Tarsus IV with a ventral row of serrated bristles constituting a comb (though this is indistinct in the males of some species). The abdomen conspicuously patterned dorsally (usually), or plain dorsally (e.g., in Dipoena inornata); sometimes exhibiting red or pink colour, but neither predominantly bright red and black nor predominantly bright red and yellow, or without any red coloration. The abdomen of the females without a cribellum. The reproductive openings of the females associated with an epigyne.
The adults making snare-webs; constructing tangled webs (usually, an irregular assemblage of criss-cross threads, in various situations), or constructing horizontal sheet webs (rarely).
British representation. 52 species in Britain; in the genera Achaearanea, Anelosimus, Dipoena, Crustulina, Enoplagnatha, Episinus, Euryopis, Neottiura, Paidiscura, Pholcomma, Robertus, Simitidion, Steatoda, Theonoe, and Theridion.
Comments. The posterior margins of the chelicerae usually lack teeth, and the male palp lacks a well developed paracymbium, the latter being often represented by a small hook near the base of the cymbium. The labium is not usually swollen distally, but is sometimes so in Euryopis, Theonoe and Robertus.
Illustrations. • Achaearanea riparia and A. tepidariorum. • Achaearanea lunata. • Anelosimus vittatus, Dipoena inornata and Crustulina sticta. • Crustulina guttata and C. sticta. • Episinus angulatus and Euryopis flavomaculata. • Steatoda bipunctata and Steatoda phalerata. • Enoplognatha ovata. • Theridion sisyphium. • Theridion pictum. • Simitidion simile, Theridion cinctum and T. varians. • Neottiura bimaculata and Steatoda grossa. • Paidiscura pallens, Theridion auratum and T. haematostigma. • Theridion sp..
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. The families of British spiders. Version: 4th January 2012. http://delta-intkey.com’.