RHODOSORUS MARINUS GEITLER: A NEW ADDITION TO THE MARINE ALGAL FLORA OF THE WESTERN HEMISPHERE

Rhodosorus marinus Geitler, previously known only from the Old World, is reported from material collected in the Florida Keys, thus taking its place with Chroothece richteriana Hansgirg in Wittrock and Nordstedt and Porphyridium cruentum (S. F. Gray) Nägeli as the third member of the Porphyridiales known for the marine algal flora of the Americas. Its apparent sensitivity to bright light, tolerance of high salinities, and possible confusion in identification, under certain conditions, with the red pigmented, coccoid, blue-green algae, are noted.