Staurosirella sp. 1

(Figs. 32-37)

Valves ovoid to elliptic. Ends rounded. Axial area linear and narrow, central area absents. Striae alternated and slightly radiate. Length: 6.1-8.3 μm; width: 3.3-4.8 μm; striae 10-12 in 10 μm. The specimens documented resemble Staurosira kjotsunarum Morales, Novais & Ector in valve morphology and dimensions; except for striae density ( S. kjotsunarum has 14-16 striae in 10 μm, Morales et al. 2012). The specimens were consistent with Staurosirella sp. 1 registered in Bartozek et al. (2018) for Brazilian samples. Bartozek et al. (2018) suggest further studies to identify this taxon.

Material examined: BRAZIL, MATO GROSSO DO SUL: Batayporã, Garças Lake, 21.IX.2017, sediment, D.T. Ruwer (Nupélia UEM - 18065-76, 18083-84, 18087, 18090-97) .