Gomphoseptatum aestuarii (Cleve) MedlinGomphomena aestuarii Cleve (1893): 55, pl. 3, fig. 4.Gomphoseptatum aestuarii — Medlin and Round (1986): 212, figs. 16–18; Witkowski et al. (2000): 222, pl. 61, figs. 17, 18; Pienitz et al. (2003): 58, pl. 17, fig. 21; Li et al. (2020).DescriptionValves linear with obtusely rounded apices, length 10.6–17.7 (9–35) µm, width 2.4–3.5 (2–4.5) µm. Raphe straight, external central endings expanded and relatively distant, axial area narrow. Distal raphe endings bent and slightly recurved in same direction at both apices. Central area transversely expanded into fascia that reaches valve margins. Distinctive pore field in foot pole. Well-developed pseudoseptum at foot pole. Transapical striae 16–20 (16–24) in 10 µm, slightly radiate to parallel at apices and punctate. Striae are crossed by longitudinal rib that runs midway between raphe and valve margin.NotesThe morphology of G. aestuarii found on the red alga S. americana at Miners Bay Wharf conforms well to the original description and images in Medlin and Round (1986) for specimens from Oregon, USA and the morphometric data provided by Pienitz et al. (2003) for a specimen from Haida Gwaii, north of the Salish Sea. iNaturalist ID: 258910079 (Fig. 20).