A considerable number of algae which had not been recorded earlier from the Dutch coast, have been collected during the last years. Partly these finds have been published already by Veldkamp (1950), Koster (1952) and Den Hartog (1953). In this paper I will deal with some other interesting marine algae, eight Phaeophyceae and two Rhodophyceae. Remarkable enough, all new finds thus far published, turned out to be large or medium-sized species. In this paper the majority of the algae mentioned are medium-sized; only 3 microscopical algae are recorded. Van Goor (1923) gives in his Algal flora only 20 microscopical species of which there are 14 native of our coast. From this we may infer that under this category many acquisitions to our flora still are to be expected.