Cymbellonitzschia diluviana Hustedt (Bacillariophyceae): Habitat and auxosporulation

The diatom Cymbellonitzschia diluviana Hustedt is an important indicator species in interglacial deposits but is rarely reported from contemporary sites. The presence of large populations in Lough Neagh, N. Ireland, made possible a study of its ecology and auxosporulation. The apical length of cells in the lake was usually between 7 and 25 mu m, but in culture there was a broader range between 5 and 42 mu m. Amongst smaller cells (