The species of the Nemoura ovocercia group (Plecoptera: Nemouridae)

The Nemoura ovocercia group is revised, and diagnostic characters are provided for adults. Of the species originally included in the species-group, N. tau Zwick and N. akagii Kawai are removed to a new group, the tau group, two additional species, N. cochleocercia Wu and N. lahkipuri Aubert, are uncertain in the position of species-group, and they are not considered in this paper. Sixteen species are included in the ovocercia-group at present, nine of them are new to science: N. anguiculus, N. dentata, N. dentigera, N. formosana, N. longilobata, N. quadrituberata, N. saetifera, N. trivittata and N. zoahensis. Seven additional spe species were already known: N. babai Kawai, N. geei Wu (= N. brevicercia Zhiltzova, syn. n.), N. kuwayamai Kawai, N. longicercia Okamoto, N. ovocercia Kawai, N. redimiculum Kawai and N. sachalinensis Matsumura. They are presently known only from East Asia including the Russian Far East, China, Taiwan and Japan.