Eunotia deficiens Metzeltin, Lange-Bertalot & García-Rodríguez 2005, 15: 48, pl. 22, fig. 5 (Figs 12–19) Valves dorsiventral, narrowing towards the ends, protracted nose-like apices slightly ventrally deflected, not detached from the valve body. Ventral margins slightly concave or sometimes almost parallel. Valve length 30–63 μm, valve width 7.5–9.5 μm. Areolae not distinguishable in LM. Striae composed of continuous rows of rounded areolae, 40–50 areolae in 10 μm (SEM). Transapical striae in the middle of the valve spaced 8–11 in 10 μm, denser at the apices, and curve towards the pole. Terminal nodules and raphe fissures positioned distant from the apical valve margin. No spines were observed. Material examined: — BRAZIL. Mato Grosso do Sul: Taguaruçú, Patos Lake, Upper Paraná River Floodplain, sediment, 23.III.2018, Ruwer et al. (Nupélia UEM 18102–22); Batayporã, Garças lake, Upper Paraná River Floodplain, sediment, 19.IV.2017, Ruwer et al. (Nupélia UEM 18065, 18068–76, 18083–84, 18086–87).

Published as part of Ruwer, Daiane Trevisan, Blanco, Saúl & Rodrigues, Liliana, 2021, Eunotia Ehrenberg (Eunotiaceae, Bacillariophyta) in a subtropical floodplain: a new species and taxonomic contributions, pp. 157-175 in Phytotaxa 505 (2) on page 159, DOI: 10.11646/phytotaxa.505.2.3, http://zenodo.org/record/5425402