Biraphid valves, lanceolate with narrow rostrate or capitate poles. A polymorphic genus, in which characteristic reduced internal valves are produced in response to osmotic stress. Plastids two per cell, formed as elongate and simple. Striae parallel or nearly so. Craticular valves consist of raphe-sternum and robust transverse bars. Craticula occurs in epipelic habitats, in fresh to brackish waters.
Light Microscope Image(s)
Each image is accompanied by the genus and species, California Academy of Sciences slide number (ie. CAS 612010), location of the specimen on the slide, and dimension in microns.