A BALTIC VARIANT OF PILAYELLA-LITTORALIS (ALGAE, FUCOPHYCEAE)

Published statements that Baltic Pilayella littoralis (L.) Kjellm. is unusually slender have been confirmed by measurements of cultured mate rial and field samples from sites in Finland and North Europe. Neither sporangial nor filament thickness normally exceeds 30 mum in Baltic p lants, whereas one or both usually does so in plants from more Atlanti c localities. Baltic material is also very euryhaline in character wit h active growth possible over a salinity range of 1.5-45 ppt. The opin ion that Baltic Pilayella constitutes a distinctive subspecies is ther efore upheld. The geographical limit of this taxon would appear to lie in the vicinity of Copenhagen, although the possibility that it may a lso occur in the innermost parts of tidal estuaries on Atlantic shores is not discounted.