2. Bruxelles, Institut Royal des Sciences Naturelles, 1954, in-4°, 346 pp + 14 coloured plates + 27 tabels , sewn, orig. stiff wrapper ( wrapper with frayed margins, interior fine and unopened). Inventory and description of the algae found in the brackish water of the Scheldt estuary near Lilloo ( downstream Antwerp ). The first part (not present here), describes the biotope.