A new species of Floronia Simon, 1887 from Baiyan Cave in Guizhou Province, China (Araneae, Linyphiidae).

Floroniahuishuiensis Zhou & Xu, sp. nov. (♂♀) is the first species in the genus Floronia to be described from Baiyan Cave in Guizhou Province, China. The new species is similar to F.zhejiangensis Zhu, Chen & Sha, 1987 but differs in structural details of the genital organs, primarily by the presence of a well-developed retrolateral tibial apophysis, a hook-shaped distal end of the radix in the male palp, and the rectangular posterior median plate in the epigyne. The illustration of copulatory organs of F.bucculenta (Clerck, 1757) and F.zhejiangensis Zhu, Chen & Sha, 1987 were reproduced here for comparison. A detailed description, photographs of the habitus and copulatory organs of the new species and a distribution map is provided.