Compare Platessa strelnikovae

Compare

Platessa strelnikovae is easily distinguishable from other relatively large-celled Platessa species, such as P. bavarica, P. montana, P. stewartii and P. hustedtii. Platessa bavarica has a rapheless valve with a very broad, elliptical axial area and a raphe valve with a very narrow, transverse central area. Platessa montana differs by its rhombic-elliptic valve shape with round to rectangular central area on the raphe valve, a narrower, lanceolate axial area on the rapheless valve and higher stria density (18–24 vs. 14–17 in P. strelnikovae). Platessa hustedtii has more parallel valve margins with an elliptic central area on raphe valve and higher stria density (17–22 in 10 μm). Platessa stewartii has narrow axial areas and relatively narrow transverse central areas on both valves. None of the other Platessa species display a horseshoe-shaped depression in the central area of the rapheless valve. This depression makes P. strelnikovae somewhat similar to P. lanceolatum, but the latter has narrow axial area and more distant striae (12–15 in 10 μm).