A New Species of the Genus <i>Cybaeus</i> (Araneae: Cybaeidae) from a Cave in Northeastern Central Honshu, Japan

A new species of Cybaeus L. Koch, 1868, C. eremospelyngus sp. nov., is described from Osawa-shonyudo Cave, Niigata Prefecture, northeastern central Honshu, Japan. This species has pale body coloration and relatively small eyes, which may be adapted to subterranean environments. In addition, C. eremospelyngus sp. nov. constructs a ‘Y-shaped’ retreat with three openings. This is the first record of a Cybaeus species that builds a retreat with three openings from central Honshu.