STUDIES ON THE GENERA GYROSIGMA AND PLEUROSIGMA (BACILLARIOPHYCEAE) -THE MARINE GYROSIGMA-SPENCERI RECORDS - GYROSIGMA-LIMOSUM STERRENBURGET UNDERWOOD NOV. SP

A species of Gyrosigma Hassall which is very common in the marine litt oral of many regions has to date been recorded as ''G. spenceri'' (Que kett) Griffith et Henfrey, or(incorrectly) as ''G. spaceri'' (W. Smith ) Cleve. ''G. spenceri'' is an illegitimate and superfluous name becau se this taxon is a synonym of the freshwater species G. acuminatum (Ku tzing) Rabenhorst. The marine littoral ''G. spenceri'' is incompatible with G. acuminatum both morphologicaly and ecologically. Despite its common occurrence, it has never been identified correctly and is here newly described and typified as Gyrosigma limosum nov. sp. Marine litt oral records of ''G. spenceri'' from the recent literature are correct ed by personal verification.