Geographic distribution of the Cybaeus kuramotoi-group (Araneae: Cybaeidae) in Okayama, Tottori and Hyogo Prefectures, western Honshu, Japan, with descriptions of five new species.

Five new species, Cybaeus bitchuensis, C. daisen, C. mimasaka, C. momotaro, and C. tajimaensis, from eastern part of the Chugoku District consisting of Okayama, Tottori and Hyogo Prefectures, western Honshu, Japan, are described under the kuramotoi-group in the genus Cybaeus (Cybaeidae). The kuramotoi-group is medium in size and characterized by presence of the copulatory plug. Geographic distributions of the five species belonging to the kuramotoi-group and C. ashikitaensis, a species closely related to the group, are shown. Their ranges are parapatric one another except for some cases of partial overlap.