Groenbladia neglecta (Raciborski) Teiling var. neglecta, BotaniskaNotiser 1952(3): 276. 1952.

Hyalotheca neglecta Raciborski, Flora, Jena 8(1): 30, pl. 3, fig. 2-3. 1895.

(Figs. 13 A-B)

Cells 3-3.6 times greater in length than width, 33-45 × 10-12 μm, 8-10 μm broad at the apex. Semicells cylindrical; truncated apical margins; parallel lateral margins; subquadrate angles; almost imperceptible median constriction; hyaline cell wall; axial chloroplast.

Material examined: BRAZIL, AMAPÁ, Macapá, Curralinho Lake, 02.VI.2007, C.B. Araújo (SP469217), 03.VII.2007, C.B. Araújo (SP469218), 14.I.2008, C.B. Araújo (SP469223), 12.II.2008, C.B. Araújo (SP469224), 26.III.2008, C.B. Araújo (SP469225), 15.IV.2008, C.B. Araújo (SP469226), 13.V.2008, C.B. Araújo (SP469227) .

Comments: the characteristic features of this species are: semicells cylindrical with truncated apical margins and parallel lateral margins, with subquadrate angles and an almost imperceptible median constriction.

Distribution in Brazil: Amazonas (Förster 1974, Souza & Melo 2010); Bahia (Oliveira 2011); Pará (Scott et al. 1965).