p. 95 - 99 SUR LE DEVELOPPEMENT EN MASSE SUR LE LITTORAL ROUMAIN DE L'ALGUE BRUNE DESMOTRICHUM UNDULATUM (J.AG.) REINKE Maria Celan 1) et Adrian Bavaru 2) 1) Institut Roumain de Recherches Marines Constanta 2) Institut Pedagogique de Constanta Abstract First cited for the Black Sea by Em. Teodorescu, Desmotrichum undulatum never figured again in the paper dealing with the algoflora of this sea; this "eclipsa" was anappearance only, the species persisting as a matter of fact as microscopical plethysmothalli known as Ectocarpidium pitreanum and Ectocarpus caliacrae.