(1) All the species of Japanese Cephaloziellaceae were critically reviewed ; they were arranged under two genera and nine species, for which a key as given. (2) Cephaloziopsis pearsonii was here first recorded from Japan. It occurs on barks of Abies shikokiana near the summit of Mt. Ishizuchi. Both morphologically and ecologically, our plants well agree with those of North America except that the branching is always of the Frullania-type. (3) Cephaloziella subdentata was also a new record for the flora of Japan. It grows on Plagiochasma sp. covering rocks at shaded and dripping places near the summit of Mt. Mitsu-toge. Our plants are slightly different from the typical ones in that the cuticle of leaf cells is not verrucose and the leaf lobes are provided with irregular, blunt teeth. (4) Cephaloziella recurvifolia is characterized by that the plants are markedly large (stems are up to even 20 cells thick), the stems are often attenuate and become flagelliform, the leaves are inserted somewhat obliquely, the bracts and the bracteole are not or slightly connate with each other and their lobes are entire, and the bracteole is poorly developed or quite absent. These features seem to be characteristic enough to propose a new genus based on this species. Acolea formosae known from Taiwan is probably conspecific with C. recurvifolia. (5) Cephalozia jishibae can not be assigned to Cephaloziella, because of the presence of of flagella, of the divided perianth-mouth, and of the irregularly arranged cells at the perianth-mouth. The species can not be placed also in Sphenolobus, as the female inflorescence is borne on a short ventral branch, the perianth is nearly trigonous in cross-section, the under-leaves are distinct even in sterile shoots, and the plants bear particular flagella. Judging from an ensemble of the characteristics, it may be better to transfer this species to Iwatsukia (Lepidoziaceae), which was recently described by the writer from North Borneo. (6) Cephaloziella minutissima may be reduced under synonymy of Cephalozia hokkodensis.

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