Staurosirella martyi (Hérib.) E. Morales & Manoylov 2006 b

Figs 8, 9, 10, 11, Supplementary material 9

Opephora martyi Hérib., 1902 (basionym) (Héribaud 1902: 43)

Fragilaria harrisonii var. γ dubia (Grunow 1862: 368)

Staurosira harrisonii var. dubia (Grunow) Cleve (Cleve and Grunow 1880: 9)

Opephora martyi var. capitata Hérib. (Héribaud 1903: 30)

Opephora cantalense Hérib. (Héribaud 1903: 30)

Opephora cantalense var. capitata Hérib. (Héribaud 1903: 30)

Fragilaria mutabilis f. martyi (Hérib.) A. Cleve (Cleve-Euler 1932: 23)

Martyana martyi (Hérib.) Round (Round et al. 1990: 673)

Fragilaria martyi (Hérib.) Lange-Bert. (Lange-Bertalot 1993: 46)

Staurosirella leptostauron var. dubia (Grunow) Edlund (Edlund 1994: 12)

Staurosira martyi (Hérib.) Lange-Bert. (Krammer and Lange-Bertalot 2000: 586)

Staurosirella dubia (Grunow) E. Morales & Manoylov (Morales et al. 2010 a: 43)

Staurosira dubia Grunow, nom. inval. (Cleve and Möller 1879: no. 270–271)

Type locality.

Dépôt de Neussargues, sample collected between the train station and L’Allagnon (Héribaud 1902: 41), Cantal, France.

Epitype locality.

Grunow sample 552, “ zwischen Aegagropila Sauteri aus dem Stienitz See bei Berlin ” (Leg. amic. Reinhardt), material conserved at W! Two samples of cleaned material (W 0164812 and W 0164813, the latter sampled) are filed in the general collection under Fragilaria intermedia .

Lectotype (designated here).

BR- 4829, slide made from Héribaud sample Dépôt de Neussargues. Figure 8 C illustrates the lectotype.

Epitype (designated here for the above selected lectotype).

BR- 4828, slide made from Grunow sample 552. Figure 10 D illustrates the epitype.

Registration.

http://phycobank.org/103844

Analysed material.

FRANCE • Dépôt de Neussargues, sample collected between the train station and l’Allagnon, Cantal, France; slide BR- 4829; BR • Dépôt de Joursac, Cantal, France, slide Collection Tempère & Peragallo (2 e edition) BM 68398; BM • zwischen Aegagropila Sauteri aus dem Stienitz See bei Berlin; leg. amic. Reinhardt; Grunow sample 552, slides BR- 4828, W 0164812 and W 0164813; BR, W .

UNITED KINGDOM • Ormesby, Norfolk; 10 Apr. 1853; leg. M. Bridgeman, Smith sample s. n., slide BR- 4830; BR .

LM description.

Frustules rectangular in girdle view, solitary, band-like colonies at present not observed. Valves heteropolar, larger valves with clear constriction between valve middle and headpole, smaller valves ovoid in shape. Headpole broadly rounded, and more acute footpole. Valve outline lanceolate in larger valves, elliptic to elliptic-lanceolate in smaller valves. Valve dimensions (n = 40): length 9–38 µm, width 5–10 µm. Sternum narrow to moderately broad, linear to lanceolate. Striae broad, wider than the virgae, parallel in the middle becoming gradually weakly radiate towards the apices, 6–7 in 10 µm. Individual areolae often discernible in LM (Fig. 8 B, C). Figure 8.

SEM description.

Headpole clearly depressed. Sternum and vimines externally weakly raised above the striae. Areolae linear, slit-like, separated by narrow vimines, the latter occasionally interconnected subdividing the areolae in two or three smaller areolae. Spines absent. Apical pore field at footpole very large, composed of more than eight long rows of small, rounded to squarish pores, extending from valve face to mantle. Apical pore field much smaller at headpole, restricted to a compact group of a few small pores. Internally, small pseudoseptum present at footpole contrary to headpole lacking pseudoseptum. Internal areola occlusions eroded due to age of material (Miocene), making observations not possible. Valvocopula very large, plain, open. Figure 9.

Associated diatom flora.

Héribaud (1902) listed several species of Navicula for the Dépôt de Neussargues including Navicula bouhardi Hérib., N. dariana var. miocenica Hérib. & Perag., N. malinvaudi Hérib., N. sculpta Ehrenb. together with Eunotia gracilis var. capitata Perag. & Hérib. and Melosira boulayana Perag. These species are most likely all extinct and their ecological preferences are currently not known. The epitype sample (Grunow sample 552) is almost entirely dominated by araphid species. Fragilaria vaucheriae (Kütz.) J. B. Petersen is the most frequently observed, followed by Staurosira cf. binodis (Ehrenb.) Lange-Bert., Gomphonema capitatum Ehrenb., Nitzschia amphibia Grunow, and Pinnularia brebissonii (Kütz.) Rabenh. Based on Lange-Bertalot et al. (2017), these species are usually found in alkaline water bodies with moderate to higher electrolyte contents and higher trophic levels.