2 SPECIES OF FOLIOSE HALYMENIA (HALYMENIACEAE, RHODOPHYTA) FROM BRAZIL

Two species of Halymenia C. Agardh (H. vinacea M. Howe et W. R. Taylor and H. brasiliana sp. nov.) from Brazil are described. It is conclude d that distinguishing features for species of Halymenia include: habit and dimensions of the plant; thickness of the frond; presence or abse nce of a differentiated stipe; presence or absence of a rib at the bas e of the thallus; and the presence or absence of a system of filaments composed of ganglioid cells with refractive contents. The characteris tics employed by different authors for the separation of species of Ha lymenia are discussed and evaluated. Halymenia bermudensis Collins et M. Howe is here proposed as being conspecific with H. floridana J. Aga rdh.