References:
Patrick, R. & Reimer, C. W. (1975). The Diatoms of the United States 2(1). Monographs of the Academy of Natural Sciences of Philadelphia. Pennsylvania. pp. 53-54; 96-97 [pl.10:2]
Description:
Valve is moderately dorsi-ventral, with rather evenly arched dorsal margin and nearly straight ventral margin with slightly gibbous central portion; extremities are only slightly tapered, broad and rounded; axial area is linear, widening slightly at mid-valve to form a shallow central area; raphe is lateral, tapering near the proximal and distal ends, becoming slightly reverse-lateral near the distal ends; ventrally deflected proximal raphe ends are rounded, while distinctly forked distal ends have extended (outer) portion that curve dorsally at about 60-75°; punctate striae are slightly radiate (especially at mid-valve) to parallel; puncta are distinct and more or less ovoid, about 11-15 in 10µm; length is 70-200µm, breadth is 20-30µm (Hustedt [1930] gives length up to 265µm, breadth up to 48µm); striae count is 7-10 in 10µm, becoming 11-12 in 10µm near the extremities
