Guide to Eolimna

The genus Eolimna was described from lake sediments of the Lower Oliogocene in the Rhön Mountains of Germany. The genus is based on E. martinii, and since its original description a few other species have been transferred into the genus.

The cells of Eolimna are small, generally less than 20 µm in length and 2-7 µm in width. A narrow central sternum is present, and the raphe is straight. Striae may be uniseriate or biseriate. Valve mantles are narrow. The proximal and distal raphe ends are deflected in opposite directions. Note, however, that the proximal raphe ends of some taxa are slightly expanded and straight. Areolae are coarse and striae are often interrupted. Valves lack apical pore fields. Areolae are positioned medially within the frustule wall and are covered internally by hymens.

Eolimna includes the former Navicula adnata. Many taxa placed in Eolimna have since been transferred to Sellaphora.