Frustules biraphid, usually observed in girdle view where the frustule appears hourglass-shaped or panduriform, and diagonally opposite portions of the frustule appear at the same level of focus. Punctate cingulum element numerous. Single valves appear to have a constriction at the center. In valve view the raphe is elevated on a keel and sigmoid.
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.