Diploneis ovalis has larger central area and a higher striae density (12-14 in 10 µm). Diploneis krammeri also has higher striae density (11-12 in 10 µm). When found associated, the striae structure is the best guide to separate Diploneis krammeri from Diploneis elliptica (not the valve size). Diploneis austriaca has conopeum, visible only under SEM.

LM scalebar = 10 µm
Diploneis elliptica LM1 Dielliptica 1 Dielliptica 2 Dielliptica 3 Dielliptica 4 Dielliptica 5
Length Range
30-65 µm
Width Range
17-36 µm
Striae in 10 µm

Diploneis ovalis

(Hilse) Cleve 1891

Diploneis Ovalis 1 Diploneis Ovalis 2 Diploneis Ovalis 3 Diploneis Ovalis 4 Diploneis Ovalis 5 Diploneis Ovalis 6 Diploneis Ovalis 7
Length Range
32.5-58.7 µm
Width Range
20.7-32.6 µm
Striae in 10 µm

Diploneis krammeri

Lange-Bert. and E.Reichardt in Rumrich et al. 2000

Diploneis krammeri LM4 Diploneis krammeri LM5 Diploneis krammeri LM6
Length Range
31-49 µm
Width Range
15-16 µm
Striae in 10 µm

Also compare to

Diploneis austriaca

Lange-Bertalot and Fuhrmann