Rabdiaster reticulata (Thomsen, 1979) Mikrjukov, 1999. emend. Nicholls, 2012
( = Pinaciophora reticulata Thomsen, 1979)
( = Rabdiophrys reticulata (Thomsen, 1979) Roijackers & Siemensma, 1988)
Diagnosis: Cells 15 – 25 µm in diameter, with tubular spine-scales 2 – 6 µm long with a solid disc-like base 0.5 – 0.7 µm in diameter and about 0.1 µm thick. The middle region of the spine shaft with parallel walls in optical cross-section, about 0.35 µm in diameter; some spines with internal short, curved rib-like thickenings at irregular intervals throughout the length of the spine shaft. Distal end of the spine-scales flared to about 0.35 – 0.65 µm in diameter with a scalloped rim ornamented with 3-5 tooth-like projections. Plate-scales, 2.5 – 3.2 µm in diameter, comprised of a double layer of siliceous sheeting, unornamented or with a few small depressions in the distal sheet (visible in TEM images of obliquely oriented scales). The space between the double layer is filled with a maze-like pattern of ribs and/or hexagonal or polygonal meshes revealed in TEM images as electron-dense dark lines and forming an elaborate ribbed network with the largest and more completely structured meshes located near the centre of the scale. Aberrant plate-scales with non-circular outlines (smaller with rounded polygonal outlines) occasionally present.
Type location: Marine, Dybso Fjord (Denmark).