Ten species are added to the Fissidens flora of Japan. Fissidens kiguchii and F. takayukii are new to science. Eight species of Fissidens, namely F. crispus, F. excurrentinervis, F. perssonii, F. platyphyllus, F. pseudoceylonensis, F. sublineaefolius, F. taylorii, and F. ventricosus are additions to the moss flora of Japan. Fissidens platyphyllus Broth., previously considered a synonym of F. amoenus Müll. Hal. is recognized as a good species. Fissidens microcladus Thwait. & Mitt. is proposed as a new synonym of F. pallidinervis Mitt. Fissidens boninensis newly found in Ibaraki-ken, Honshu, Japan.
Two species of Diphyscium are added to the moss flora of Japan. D. yakushimense is new to science. D. malayense which was previously considered a synonym of D. mucronifolium, is recognized as a good species and added to the moss flora of Japan.
The genus Brotherella M. Fleisch. is a member of the Pylaisiadelphaceae and many of the species are distributed in East Asia. A few species have been reported from Europe, North and Central America. Since Fleischer proposed the genus Brotherella in 1914, sixty five taxa have been described. Fifteen species of Brotherella are accepted after the revision: Brotherella canadensis W.B. Schofield, B. complanata Reimers & Sakurai, B. curvirostris (Schwägr.) M. Fleisch., B. cuspidata Y. Jia & J.-M. Xu, B. deplanatula (Cardot) Broth., Brotherella erythrocaulis (Mitt.) M. Fleisch., B. falcata (Dozy & Molk.) M. Fleisch., B. fauriei (Cardot) Broth., B. henonii (Duby) M. Fleisch., B. longipes Broth., B. luzonensis (Broth.) M. Fleisch., B. minutula E.B. Bartram, B. nictans (Mitt.) Broth., B. opaeodon (Sull.) Broth. and B. recurvans (Michx.) M. Fleisch. Brotherella crassipes Sakurai, B. herbacea Sakurai, B. indosinensis (Broth. & Paris) Broth. and B. roellii (Renauld & Cardot) M. Fleisch. are proposed to be new synonyms. Brotherella luzonensis (Broth.) M. Fleisch. is reported new to China, while Brotherella erythrocaulis (Mitt.) M. Fleisch. and B. fauriei (Cardot) Broth. are reported for the first time in North America. A key to the species is provided.