Cells with wedge-shaped girdle-band side and wedge- or club-shaped valve. Two intercalary bands in resting cells, with a more or less long penetrating septum on the head pole. Valves with transapical punctated striae, seldom with weak transapical ribs and extremely delicately punctated intercalary space. Pseudoraphe usually distinct, often developed as a strong siliceous rib. Chromatophores are numerous small granules or a few larger plates. Auxospore
formation, so far as known, consists of one asexual auxospore in one mother cell. Littoral marine species are held to the substrate by a shorter or longer, often branched gelatinous stalk (Cupp, 1943).
Cupp, 1943: p. 177, Fig. 127; Witkowski et al., 2000: p. 63, Pl. 20: 3-5.
Cells in girdle view usually strongly wedge-shaped with moderately rounded upper corners, deeply penetrating septa, and more or less strongly waved intercalary bands. Valves narrow club-shaped, with wide, usually somewhat wedge-shaped rounded head and more acute rounded foot pole. In the lower part slightly concave. Apical axis 40-80 µm long; transapical axis 4-8 µm; transapical striae fairly strong, on the base, 10-12 in 10 µm, in the upper part of the valve becoming weaker, near the upper (head) pole 13-16 in 10 µm. Pseudoraphe narrow, but distinct (Cupp, 1943).
Cells length 65-90 µm; width 8-13 µm.
Widespread littoral, but often found in plankton collections.
Sites of occurrence in RSA:
In Winter 2006 Cruise, it was present in small numbers at scattered stations (refer sites map).