References:
Patrick, R. & Reimer, C. W (1966). The Diatoms of the United States I. Monographs of the Academy of Natural Sciences of Philadelphia. Pennsylvania. pp. 279-280; 292-293 (pl.19:15)
Description:
Valve is twice strongly concave with gibbous centre and capitate extremities; valve surface is highly arched and longitudinally undulate; raphe valve has linear, slightly sinuous axial area flaring into widening stauros; pseudoraphe valve has narrow, linear, eccentric pseudoraphe that is submarginal to marginal and has no central area; raphe is as sinuous as axial area, twice recurved, with proximal raphe ends rounded (ends do not protrude into central fascia) and distal ends curving in the same direction; striae are composed of large distinct puncta (10-12 in 10µm [RV], about 9 in 10µm [PRV]) on both valves, but are slightly radiate on raphid valve and parallel on pseudoraphe valve (except at the ends, where they become curved and radiate); length is 30-65µm, breadth is 10-18µm; striae count is 10-13 in 10µm(RV), 9-11 in 10µm (PRV)