This taxon has a moderately sigmoid and lanceolate valve. The valve tapers to narrow and rounded ends. The axial area and the raphe are slightly undulate and the terminal area is slightly eccentric. This taxons has a small and longitudinally elliptical central area and the transverse and longitudinal striae are equally distinct (Patrick and Reimer 1966).
Synonyms
Navicula spencerii Quek., Pract. Treat. Micr., p. 440, pl. 9. 1848 (Patrick and Reimer 1966).
Pleurosigma spencerii(Quek.) W. Sm., Ann. Mag. Nat. Hist., ser. 2, 9:12, pl. 2. fogs/ 15-16. 1852 (Patrick and Reimer 1966).
Pleurosigma kutzingiiGrun., Verh. Zool.-Bot. Ges. Wien, 10:561, pl. 6, fig. 3. 1860 (Patrick and Reimer 1966).
Pleurosigma gracilentumRabh., Fl. Europaea Alg., sect. 1, p. 240. 1864 (Patrick and Reimer 1966).
Gyrosigma kutzingii(Grun.) Cl., K. Svenska Vet.-Akad. Handl., Ny Foljd, 26(2):115. 1894 (Patrick and Reimer 1966).
Ecology
This taxon is common in creeks, rivers and lakes. It is alkaliphil, oligohalobe and can stand some salt concentration(Patrick and Reimer 1966).