Navicula alterofasciata, a new subfossil diatom from a Dutch lake sediment

Navicula alterofasciata, spec, nov., described from post-glacial lake sediments dating from the Preboreal up to and including the Atlanticum, is characterised by a fairly large, asymmetrical central area and a very fine, lightmicroscopically hardly discernible strialion, and can provisionally best be referred to the section Naviculae subtillisimae Hustedt.