Frustules biraphid, raphe elevated from the valve in a keel. Valves lanceolate with narrow poles, with fold appearing as lines on either side of the raphe system. Parallel striae are distinct, axial area is narrow and the central area variable in shape. In girdle view frustules appear constricted at the center on both valves.
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.