Ctenophora pulchella var. fasciculata
Araphid - Valves are linear-lanceolate to lanceolate. The apices are set off slightly, rounded but not capitate. The axial area is very broad. No central area is evident. Striae are costate.
Centric - The valve face is tangentially undulate. Striae are coarse and organized into somewhat radial rows. A ring of marginal fultoportulae is present. A prominent rimoportula is present on the valve face, close to the margin.
Centric - Valves are flat, with short mantles. Areolae are fine. A single, prominent rimoportula is present on the valve margin.
Nitzschioid - Valves are linear and slightly concave in the middle of the valve. The apices narrow, drawn out and narrowly rounded. A narrow, indistinct fold runs along the longitudinal axis of the valve. The fold is barely undulate, or may not appear elevated or depressed from the main valve surface. Transapical ribs are distinct. Striae are indistinct.
Nitzschioid - Valves linear, slightly concave in the middle, with the ends protracted slightly and bluntly rounded. Raphe keel with distinct fibulae numbering 8-11 in 10 µm. A longitudinal fold is wide, running the entire length of the valve.