1–5 Improphantes improbulus. 6 – Live Metellina merianae in Gavrilovskaya II Cave, feeding on Diptera. 7 – Letuchikh Myshei Cave. 8 – Gavrilovskaya II Cave. 9–10 –The map of caves where spiders were searched for. Filled circles – caves where spiders were collected; open circles – caves where no spiders were found. The numbers of caves correspond to that in the material and methods. Frame on Fig. 10 refers to Fig. 9. 1 – Habitus, dorsal. 2–3, 5 – Epigyne, ventral, dorsal and lateral. 4 – Abdomen with intact epigyne. Scale bars: 0.2 mm (1); 0.05 mm (2–3, 5); 0.1 mm (4).