Five species of the genus Caenis from Chinese mainland are reviewed. Among them, C. parviforcipis (Zhou et al.) (nov. comb.) is transferred from the genus Brachycercus The larvae of the C. sinensis Gui et al. are described for the first time. The previously reported C. nigroforceps Zhou et al. is recognized as a new synonym of the Caenis rivulorum Eaton, and the report of C. nigropunctata Klapálek from China is confirmed. Both imagos and larvae of a new species C. melanoleuca, sp. nov. are described and illustrated in detail.
In present paper the genus Rhithrogena Eaton from Chinese mainland, including a new species to science (Rhithrogena lutea, sp. nov.), 2 new record species from China (R. bajkovae Sowa, R. lepnevae Brodsky) and 3 known species [R. wuyinensis (Gui et al.) (comb. nov.), R. trispina Zhou et Zheng, R. orientalis You (= R. sangangensis You, new synonym)] are revised besed on the imaginal specimens. A key to 7 species imagos is provided. All materials in this study are deposited in Nanjing Normal University.
