Compare Diploneis texana

Compare

Diploneis pseudovalis is very similar, and overlaps in size range. While D. pseudovalis somewhat more oblong shape, these taxa may be easily confused and D. pseudovalis was commonly reported in Montana (L.L. Bahls, personal communication). Diploneis puella is smaller in size and has a narrow axial area, small central area, and higher stria density. Diploneis heteromorphiforma has uniseriate striae, becoming biseriate toward the valve margin. Diploneis iovanovskae much more narrowly spaced areolae, 35–40 in 10 μm.

Note that the differences between D. pseudovalis, D. iovanovskae, and D. texana are mainly in the number of areolae that make up the striae, a feature that requires optimal illumination and a critical eye. The striae are biseriate in D. pseudovalis, triseriate and very fine in D. iovanovskae, and triseriate becoming multiseriate in D. texana. Other features either overlap, or are of questionable value, considering possible environmental influences on morphology.