Cocconeis voigtii F. Meister (Bacillariophyta) and other species from Meister’s and Voigt’s Nagasaki (Japan) material

Meister (1935, 1937) described from a marine sample (‘Nagasaki, on shell’ from Nagasaki, Japan, collected by Manfred Voigt in 1933–1934) numerous new diatoms (Bacillariophyta), among which were nine species pertaining to the genus Cocconeis. Several of these taxa were originally succinctly described and often only illustrated by their sternum valve (SV). Afterwards, most of these new taxa were never cited again in the literature. Cocconeis voigtii is typified here, its original diagnosis amended with the description of its raphe valve (RV) and possible synonymies considered. A taxon from which the SV shows similarities with Cocconeis callosa, except for its stria density, is discussed and its relationships with C. sigmoradians envisaged. Cocconeis delicata, originally described by A. W. F. Schmidt, is reinvestigated. Several other taxa, present in the material from Nagasaki, and rarely mentioned in the literature, were noticed neither by Meister nor by Voigt in spite of their unique features, i. e., Cocconeis cyclophora var. decora and a new variety, Cocconeis cyclophora var. meisteri var. nov. described herein