TwoPeyssonneliaspecies (Peyssonneliaceae, Rhodophyta) from Puerto Rico includingPeyssonnelia flavescenssp. nov

Two highly colourful encrusting red algal species from deep and shallow coral reef habitats in Puerto Rico are reported. Peyssonnelia boergesenii Weber Bosse is characterized by its multicoloured appearance, polyflabellate arrangement of hypothallial cells and multicellular holdfasts. Peyssonnelia flavescens sp. nov. is variably bi- to tri-coloured, with the principal background colour bright yellow to tan. It forms large crusts, to 30 cm in diameter, which are variably thick, measuring 310–640 μm in thickness. The new species differs from other known Peyssonnelia species by cutting off elongate, 12–17 μm long, spermatangial initials that cut off seriate chains of spermatangia distally and by its production of very large tetrasporangia, to 170 μm long.