Encyonema auerswaldii

Valves are strongly arched dorsally and slightly tumid ventrally, with rounded ends. In larger specimens, the ends may be slightly rostrate. Dorsal striae are parallel near the center, becoming radiate near the ends. Ventral striae are slightly radiate. Areolae in each stria are clearly visible and number approximately 25 in 10 µm. The axial area is slightly lanceolate; it is narrow near the ends and slightly expanded and rounded in the central area. The raphe is broad and lateral. The proximal raphe ends are dorsally deflected, while the distal raphe ends are ventrally deflected.

Living cells form mucilage tubes, where they live as colonies inside the tubes.

The lectotype of E. auerswaldii was examined and compared to types of E. prostratum and E. cespitosum (Silva et al. 2013). They report that specimens of E. prostratum are broader than E. cespitosum (16–24.7 μm versus 9.6–12 μm). The maximum length of E. prostratum was reported as 88 μm, and the maximum length of E. cespitosum was reported as 47 μm.