Luticola ventricosa

Valves are linear, with capitate apices. The axial area is narrow and linear. The central area is bow-tie-shaped to transapically rectangular ,or elliptic. A single stigma is located slightly closer to valve center than to the margin. The raphe is straight and filiform. The proximal raphe fissures are curved to the primary valve side. Similarly, the distal raphe fissures are curved to the primary valve side. Striae are coarsely punctate and radiate. The striae are composed of 4-5 areolae. The areolae are variable in size; the areolae are largest near the valve margin and they decrease in size closer to the sternum.

Note that these specimens are more elongate than the original illustrations of Kützing (1844). Further work is needed to determine the features of the type material and if this North American form is a distinct taxon. This species should not be confused with Antarctic species that are capitate, but have a number of other distinguishing features (Kohler et al. 2015).