Lyrella approximata (Grev.) 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 : 30-31

Lyrella approximata (Grev.) D.G. Mann in Round et al. (1990: 671)

Basionym: Navicula approximata Grev. (1859: 28, pl. 4, fig. 4)

Navicula lyra var. approximata (Grev.) Cleve (1878: 4; pl. 1, fig. 1)

Valves linear to linear-elliptic with almost parallel margins and slightly wedge-shaped protracted apices, length 60–120 µm, breadth 30–50 µm. Raphe straight, external central endings relatively approximate, axial area narrowly linear, central area relatively large, apically elongate, connected to lateral areas. Lateral areas narrow, convex, terminating below apices, structureless. Transapical striae in the marginal zone radiate, ca. 10 in 10 µm, distinctively punctate, areolae ca. 16 in 10 µm (cited from Witkowski et al. 2000: 230).

Distribution:—Marine species usually found in warm water oceans, in Europe known from the Mediterranean ( Witkowski et al. 2000). Black Sea, Bulgarian coast (Temniskova-Topalova & Petrova- Karadjova 1998).

Literature:— Greville (1859: 28, pl. 4, fig. 4); Hustedt (1961 –1966: 415, fig. 1490); Round et al. (1990: 671); Witkowski et al. (2000: 230, pl. 97, fig. 9); Temniskova-Topalova & Petrova-Karadjova (1998: 75, no micrograph)