Anorthoneis pulex Sterrenburg 1987: 16

Pennesi, Chiara, Majewska, Roksana, Sterrenburg, Frithjof A. S., Totti, Cecilia & Stefano, Mario De, 2018, Taxonomic revision and morphological cladistics analysis of the diatom genus Anorthoneis (Cocconeidaceae), with description of Anorthoneis arthus-bertrandii sp. nov., Phytotaxa 336 (3), pp. 201-238 : 224-225

Anorthoneis pulex Sterrenburg 1987: 16 ( Figs 93–96 )

References:— Sterrenburg (1987), p. 15, 2 figs; Sterrenburg (1988), p. 375, pl. 3, figs 16–23, pl. 4, fig. 28; Witkowski et al. (2000), p. 98, pl. 51, fig. 2.

Description:— Valves broadly elliptical to ovoid in outline ( Figs 93–96 ). Apical axis: 8.5–14.5 μm, transapical axis: 7.5–9.5 μm.

SV:— Externally, valve face flat to convex, curving into a shallow undistinguishable mantle ( Fig. 95 ). Sternum strongly asymmetrical, narrow, expanding in its central part into hyaline central area, which covers circa half of the valve surface ( Fig. 95 ). Striae uniseriate, almost parallel in the center of the valve, becoming strongly radial at the poles (18–22 in 10 μm). Areolae rounded (20–22 in 10 μm) ( Fig. 95 ), internally occluded by perforated hymenes ( Fig. 96 ). Internally, valve structures similar to the external ones ( Fig. 96 ).

RSV:— Externally, valve almost flat ( Figs 93, 94 ). Asymmetrical raphe-sternum expands into a strongly asymmetrical hyaline central area ( Figs 93, 94 ). Raphe straight with clearly marked central nodule ( Figs 93, 94 ). Striae uniseriate ( Figs 93, 94 ) and radiate, approx. 30 in 10 μm, and composed of rounded areolae. Internally, valve structures similar to the external ones.

Figures

FIGURES 93–96. Historical reports of Anorthoneis pulex by different authors. 93–94. A. pulex specimens from Sterrenburg (1987), slide BM 81499, Yerseke, The Netherlands. 95. Teratological valve from Sterrenburg’s cleaned material from Yerseke, The Netherlands, SEM image. 96. A. pulex sternum valve from Sterrenburg’s cleaned material from Yerseke, The Netherlands, SEM image. Magnification: Fig. 97: x1500. Scale bars: Figs 93–94 = 5 μm; Figs 95, 96 = 2 μm.