Botanica Marina 50: 128-140
Griffithsia aestivana sp. nov. is described as an endemic from Bermuda. Vegetatively, it is most similar to G. capitata from the eastern Atlantic, but the two differ in overall size and in the tetrasporic state. Eleven other marine algal taxa are reported from Bermuda for the first time: Anadyomene howei, Struvea elegans, Cladophoropsis macromeres, Derbesia turbinata, Caulerpa racemosa var. lamourouxii, Halimeda discoidea, Chrysymenia nodulosa, Gloiocladia iyoensis, Dasya caraibica, Chondrophycus iridescens and Polysiphonia scopulorum. All except D. turbinata represent new northern limits of distribution in the North Atlantic. In addition, recent Bermuda collections of the invasive Mediterranean Cystoseira compressa and the rarely found Womersleyella setacea are detailed.
Key words: Alien species; Bermuda; Cystoseira compressa; Gloiocladia iyoensis; Griffithsia aestivana sp. nov.