The genus Phaeolejeunea is new to the Fiji Islands, represented by one species previously known only from 'Eua (Tonga Islands) under the name Phaeolejeunea etesseana Mizut. ssp. amicorum Hürl. As a result of a study of all species of the genus, this taxon proved sufficiently distinct as to warrant recognition at the rank of species. It is endemic to the Fiji and Tonga islands, at the border of Eastern Melanesia and Western Polynesia in the Southern Pacific. First observations on the oil-bodies of Phaeolejeunea are given.