The mosses of the Wadden Sea islands Rottumeroog, Vuurtorenduin and Zuiderduin (part 2) This is the second paper on the bryophyte flora of the West Frisian barrier islands Rottumerplaat, Rottumeroog, Vuurtorenduin and Zuiderduin. The first paper (Kruijer et al., 2000) gives an overview of the recent geologic history of the islands and presents the findings of the bryophyte inventories in 1999. This follow up includes additional records of bryophytes from Rottumeroog collected in 1994, supplements the 1999 inventory of Rottumeroog and Zuiderduin, and presents the findings of the 2001 inventory of these islands and Vuurtorenduin; the bryoflora of Vuurtorenduin was previously unknown. The 2001 inventory results in a list of 36 bryophyte species on Rottumeroog, 6 species on Vuurtorenduin, and 5 species on Zuiderduin. We have found no significant changes in the total number of bryophyte species on Rottumer-oog since 1973, despite the occurrence of dramatic events in this period. The bryo-logically most interesting site on Rottumeroog ('tuin van Toxopeus') has disappeared by floods in 1998-1999 together with, amongst others, the rare species Moerckia hibernica en Bryum calophyllum. Interesting 'new' species are, amongst others, Eurhynchium speciosum, Hylocomium splendens, Orthotrichum affine, O. diapha-num, Tortula truncata, Cephalozia bicuspidata, and Cephaloziella divaricata. These species were only found in the proximity of the 'tuin van Toxopeus' and are under threat to be swallowed by the sea. Dicranum scoparium and Syntrichia ruralis var. ruralis are 'new' species for Rottumeroog which have not been found again in 2001: the growing site of Dicranum scoparium has been covered by sand, the growing site of S. ruralis var. ruralis (roof of a building) has been destroyed.