The valves are lanceolate-elliptical with convex margins and bluntly round ends (Figs 246–249, 252). The valve length is 13.5–21.0 μm, and the breadth is 6.0–7.0 μm. The axial area is linear throughout the whole length. The central area is small and rectangular, ca. 0.5–1.0 μm wide. The longitudinal canal is lanceolate, slightly expanding at the valve apices (Figs 251, 252). The external openings of the canal are covered with volate occlusions (Fig. 252). Externally, the raphe is straight with simple and slightly expanded proximal and distal ends (Figs 250–252). Distally, the raphe branches terminate some distance from the valve margins (Fig. 251). The striae are parallel in the middle of the valve, becoming radiate toward the valve apices, 26–27 in 10 μm. The single areola in each stria is covered with a volate occlusion that occupies less then half of the valve width (Fig. 252). The hyaline area that covers part of the alveolate striae is lanceolate and broadly widens at the middle of the valve (Fig. 252).

Ecology and Distribution: —M166A; M068A: found on rocks in shallow habitats in southern Lake Hövsgöl and in small streams in Arkhangai province.