The genus is thought to be monotypic in North America. In Asia, L. superlacustris has broader valves (25-29 µm), lower stria (10-12 in 10 µm) and areola density (7.5-12 in 10 µm). Lacustriella acutocuneata has linear margins, a weakly expanded central area and acute apices. Lacustriella perapiculata has a weakly defined central area and a lower stria density (13-14 in 10 µm).

LM scalebar = 10 µm
Lalacust  Mbe2215A 1051 48 Lacustriella lacustris LM1 Lacustriella lacustris LM4 Lacustriella lacustris LM2 Lacustriella lacustris LM3 Lacustriella lacustris LM6
Length Range
36.4-47.0 µm
Width Range
16-18 µm
Striae in 10 µm
14-15 at the valve center, 15-16 at the apices

Also compare to

Lacustriella superlacustris

Metzeltin, Lange-Bert. and Kulikovskiy

Lacustriella acutocuneata

Metzeltin, Lange-Bert. and Kulikovskiy

Lacustriella perapiculata

Metzeltin, Lange-Bert. and Kulikovskiy