Taxonomic Notes on Marine Algae from Malaysia. X. Four Species of Dasya (Rhodophyceae), with the Descriptions of Dasya longifila sp. nov. and D. malaccensis sp. nov

Four species of the red algal genus Dasya (Dasyaceae, Ceramiales), including two new species, are reported from Malaysia. Dasya iyengarii Boergesen and D. pilosa (Weber-van Bosse) Millar are reported from Malaysia for the first time, and their morphological features are described along with taxonomic comments. Dasya longifila Masuda et Uwai, sp. nov. is chiefly distinguished by its long, monosiphonous, pseudolateral filaments (often longer than the axis) in which intercalary cell divisions take place, and a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral from several related species that possess small-statured, sparsely corticated axes. Dasya malaccensis Masuda et Uwai, sp.nov.is characterised by its diminutive thallus (up to 10 mm high) with thickly corticated axes, relatively short pseudolaterals, and narrow tetrasporangial stichidia and spermatangial branches. This species has no close relatives among small-sized species of Dasya.