Current results of an arachnological survey of some sandstone rock sites in Bohemia (so called 'rock cities'). The spider fauna of the Adrspach·Tepllce rocks was investigated. Some records on spider fauna of other nine sandstone rock areas are included. The phenomenon of 'rock cities' manifests itself in three aspects: (1) In the bottom parts are microclimatically cold spaces, frequently hosting northern or mountain species of invertebrates, which here have an azonal occurrence. (2) The sun exposed tops of rocks can host thermophilous species. (3) Some species are limited to the surface of rocks and boulders. These are referred to as lithophilous or lithobiont species.
The arachnofauna was studied at five stony debris sites in northern Bohemia. In Central Europe, the northern and montane species inhabiting cold places live not only on mountain tops and peat bogs but also on the lower edges of boulder debris, where air streaming through the system of inner compartments gives rise to an exceedingly cold microclimate. At such cold sites, spiders can live either on bare stones (Bathyphantes simillimus, Wubanoides ura/ensis), or in the rich layers of moss and lichen (Dip/oeentria bidentata). Kratoehviliella bieapitata exhibits a diplostenoecious occurrence in stony debris and on tree bark. Latithorax faustus and Theonoe minutissima display diplostenoecious occurrence in stony debris and on peat bogs. The occurrence of the species Seotina eelans in the Czech Republic was documented for the first time.
Tmeticus affinis (BLACKWALL, 1855), Tetragnatha shoshone LEVI, 1981, Clubiona juvenis SIMON, 1878, Marpissa Canestrinii NINNI, 1868, and Theridiosoma gemmosum (L. KOCH, 1877) are new records for the Czech Republic. New data about Enoplognatha caricis (FICKERT, 1876), Theridion hemerobium SIMON, 1914, Rugathodes instabilis (O. P. CAMBRIDGE, 1871), Tetragnatha striata L. KOCH, 1862, and Dolomedes plantarius (CLERCK, 1757) are given. The validity of the name Enoplognatha caricis (FICKERT, 1876) is supported.
