A NEW SPECIES OF SIGMOID NITZSCHIA(BACILLARIOPHYTA)

A new sigmoid marine diatom of the genus Nitzschiawas found in samples from near Elat, and investigated using light and electron microscopy. This species, N. paeneperpetuasp. nov., is described and discussed in relation to other sigmoid Nitzschiae, from most of which it differs markedly in valve and raphe structure. It also has unusual loculate areolae and is remarkable for the size of its valve, which can be up to 835 Mm long. Within Nitzschiait is probably most closely related to the species clustered around N. obtusa.