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. 251-252; 286-287 [pl.16:3-4]
Description:
Valve is linear or slightly linear-elliptical with broad, obtusely rounded ends that sometimes appear as broad and subrostrate; raphe valve has a narrow, linear axial area that tapers slightly at the valve ends and leads to a (usually) narrow and stauroid central area (this area varies in shape depending on the length of the central striae); raphe is filiform, with proximal ends that do not protrude into the central area, and indistinct (but apparently straight) distal ends; slightly radiate striae are not noticeably punctate or lineate; pseudoraphe valve has a narrow, linear pseudoraphe that leads to a small, linear elliptical space (if any); striae are as on raphe valve; length is 10-20µm, breadth is 2.5-3.5µm; striae count is ~24-26 in 10µm at the centre, becoming ~28-29 in 10µm at the ends (RV), and 23-26 in 10µm at the centre, becoming 28-29 in 10µm at the ends (PRV); Round & Bukhtiyarova (1996) designates Rossithidium as a new genus, combined with lineare as nov. comb.; the description is as above, but they also describe the new genus as having linear to linear-lanceolate with rounded apices, and a narrow sternum on both valves; striae are unbroken in the centre in rapheless valves, but continuous, slightly separated or with central stauros on raphid valve; raphe is straight with slightly swollen central ends and deflected terminal ends; length is 8-40µm, breadth is 3-6µm; striae count is ~20-30 in 10µm
