Some marine brown algae new or rare to The Netherlands

Descriptions and illustrations are given of five brown algal species considered to be new to The Netherlands, viz,: Laminariocolax tomentosoides, Mikrosyphar porphyrae, Myrionema aecidioides, Pogotrichum filiforme, and Protectocarpus speciosus, and five species which have rarely been recorded previously, viz.: Feldmannia irregularis, Leathesia difformis, Punctaria latifolia, Sorocarpus micromorus, and Ulonema rhizophorum. Some notes are given on their distribution and ecology, and in some cases results of preliminary culture studies.