The Algae transported on drifting objects and washed ashore on the Netherlands coast

Little attention has been paid till now to the algae, transported to the Netherlands coast on drifting objects. About a century ago T. D. Vrijdag Zijnen and G. Bisschop (near Scheveningen, ± 1845), and L. H. Buse (between Wijk aan Zee and Zandvoort, ± 1840—1847) were the first to pay attention to this subject. The material collected, especially that by the first two investigators, is mentioned in the Prodromus Fl. Bat. (1853). The book of Van Goor (1923) contains a chapter on these algae, in which, however, only few new observations occur. The author is much indebted to Dr Josephine Th. Koster for her kind help, as well as to Dr S. J. v. Ooststroom. The material, collected by Vrijdag Zijnen, Bisschop and Buse is almost completely present in the collections of the ‘Rijksherbarium’ and the ‘Koninklijke Ncderlandse Botanische Vereniging’, Leiden. The material, collected during the last few years has for the greater part been brought together by the present author, and furthermore especially by K. Swennen (Den Helder), J. Stock (Amsterdam), A. Mulder (Haarlem) and P. Leenhouts (Scheveningen). This material belongs to the collection of the Rijksherbarium, Leiden, but most of it is, for the time being, put under the charge of the “Comité ter Bestudering van de Nederlandse Mariene Flora en Fauna” (“Committee on the Netherlands’ Marine Flora and Fauna”) and temporarily preserved in “Het Filiaal”, Leiden.