Cosmarium auriculatum var. verrucosum W.B.Turner 1892

    Cell medium size measures 43-49 μm length and 50-56 μm width. Median constriction deep, sinus broadly opened isthmus 19-22 µm. Semicells elliptical with broadly rounded apex sometimes slightly truncated. Lateral margins distinctly verrucose with 4-5 sharp spines. Semicells elliptical in vertical view and circular in lateral view, cell wall smooth.