Scale Bar = 10 micrometers

Valves are large, 180-200 micrometers. Proximal raphe ends deflect ventrally. Valves thickly silicified. Areolae are elliptical and punctate. Central area is enlarged and lacks stigmata. Valves are wider than the width range described for C. lanceolata.

These specimens were collected from a dense algae mat growing on a boulder in a cold fast-flowing stream.