Navicula germainii

Valves are lanceolate with drawn-out apices. The axial area is narrow and straight. The central area is slightly asymmetric and elliptical. The raphe is straight, with external proximal raphe ends slightly dilated and bent toward the primary side of the valve. The central nodule is asymmetrically expanded on the internal valve surface to the primary side. Terminal raphe fissures are hooked to the secondary valve side. Striae are radiate around the center, 13-15 in 10 µm, becoming parallel then convergent at the apices. The areolae are often visible under LM, ca. 30-32 in 10 μm.

Note that this concept of Navicula germainii follows that of Lange-Bertalot (2001), but differs from the original concept of Wallace (1960), who did not distinguish between N. germainii and N. rostellata sensu Lange-Bertalot. Patrick (Patrick and Reimer 1966) designated a lectotype specimen of Navicula germainii, but Patrick's circle on holotype slide of N. germainii contains several specimens of both N. germainii and N. rostellata sensu Lange-Bertalot. The illustration of the lectotype in Patrick and Reimer (1966, Fig. 48:8) does not correspond to any of these specimens.