Lyrella clavata (W. Greg.) D.G. Mann

Nevrova, Elena, Witkowski, Andrzej, Kulikovskiy, Maxim, Lange-Bertalot, Horst & Kociolek, J. Patrick, 2013, A revision of the diatom genus Lyrella Karayeva (Bacillariophyta: Lyrellaceae) from the Black Sea, with descriptions of five new species, Phytotaxa 83 (1), pp. 1-38 : 27

Lyrella clavata (W. Greg.) D.G. Mann in Round et al. (1990: 672) ( Figs 68–71 )

Basionym: Navicula clavata W. Greg. (1856: 46, pl. 5, fig. 17)

Navicula hennedyi var. clavata (W. Greg.) Van Heurck (1885: 93)

Schizonema clavatum (W. Greg.) Kuntze (1898: 552)

Valves elliptic with short rostrate, obtusely rounded apices, length 30–110 µm, breadth 20–60 µm. Raphe straight, external central endings expanded, relatively close to one another, axial area narrow, linear, central area small, connected to large lateral areas. Lateral areas hyaline, broadly lanceolate, encompassing ca. 1/5 of the valve width, terminating at the valve margin. Transapical striae slightly radiate, 10–14 in 10 µm.

Distribution:—Marine species, widespread in Europe from the Mediterranean up to the Norwegian coasts ( Witkowski et al. 2000). Black Sea, Romanian ( Bodeanu 1987 –1988) and Crimean coast (Laspi Bay, Nevrova 2011 unpubl. observ.).

Literature:— Gregory (1856: 46, pl. 5, fig. 17); A. Schmidt et al. (1874–1959: pl. 3, fig. 13 as Navicula clavata var. elliptica A. Schmidt ); Hustedt (1961 –1966: 444, figs 1509 a–c); Round et al. (1990: 672); Witkowski et al. (2000: 231, pl. 97, fig. 6).

Figures

FIGURES 68–74: Figs 68–70: Lyrella clavata, valve view, LM, scale bar = 10 µm. Specimens from the Black Sea (Omega Bay, Laspi Bay). Fig. 71: reproduction of line-drawing published by Schmidt et al. (1874–1959: pl. 3, fig. 13, as Navicula clavata var. elliptica), scale bar = 10 µm. Figs 72, 73: Lyrella fogedii, valve view, LM, scale bar = 10 µm. Fig. 74: Lyrella cf. fogedii, SEM, external view, scale bar = 8 µm. Specimens from the Black Sea (Balaklava Bay, Omega Bay, Laspi Bay).