Compare Neidium hercynicum
Compare
Neidium bisulcatum has parallel striae in the central valve, becoming radiate toward the ends, and convergent at the apices.
Neidium alpinum has fine, oblique striae. The stria density, however, is higher (36 in 10 µm). Valves are smaller and more narrow (length 16-22 µm, width 4.5-5 µm).
Neidium herramanii has linear valves, and the deflected proximal raphe ends extend nearly to the edge of the central area. Striae are coarser and are oblique only near the central valve.
Neidium alpinum var. quadripunctatum is difficult to differentiate. However, the striae are parallel to very slightly oblique at the center of the valve and striae number 30-38 in 10 µm.
LM scalebar = 10 µm
Length Range
25.1-43.6 µm
25.1-43.6 µm
Width Range
7.1-8.4 µm
7.1-8.4 µm
Striae in 10 µm
23 – 29
23 – 29
Also compare to
Neidium alpinum
BioData Reference
Krammer and Lange-Bertalot 2/1 Pl 101 Fig 13-17