The highly arched dorsal margin and irregular shortened striae of E. bilii valves distinguish it from E. hexaglyphis. The absence of fine radiate striae near the ends in E. bilii distinguish it from E. subpolyglyphus.
LM scalebar = 10 µm
Length Range
29-50 µm
Width Range
10-13 µm
Striae in 10 µm
7-10 in the center valve, 10-16 at the ends