Thanks to Algis Vilkas for species identification.
Spiders in Lithuania: Vorai - Wikipedija, Mažeikių krašto vorai.
Spiders of Europe

Spiders are air-breathing chelicerate arthropods that have two body segments, eight legs, and no chewing mouth parts. About 40,000 species have been identified. In spiders' bodies the usual arthropod segments are fused into two tagmata, the cephalothorax and abdomen, joined by a small, cylindrical pedicel.