Trieres regia (M. Schultze) Ashworth & E.C. Theriot

Sims, Pat A., Williams, David M. & Ashworth, Matt, 2018, Examination of type specimens for the genera Odontella and Zygoceros (Bacillariophyceae) with evidence for the new family Odontellaceae and a description of three new genera, Phytotaxa 382 (1), pp. 1-56 : 6

Trieres regia (M. Schultze) Ashworth & E.C. Theriot ( Figs 8–13 )

Basionym:— Denticella regia M. Schultze (1859: 21 , pl. 2, figs 11, 12)

Synonyms:— Biddulphia regia (M. Schultze) Ostenfeld (1908: 7 , fig. 3) Odontella regia (M. Schultze) Simonsen (1974: 27) Type:— “North Sea” ( Schultze 1859: 13)

Frustules in girdle view rectangular with narrow tubular elevations at apices and two long spines lying between. Apical axis 90–200μm, areolae 14 in 10 μm ( Hendey 1964, Hasle & Syvertsen 1996). Valves broadly lanceolate with tubular elevation rising from expanded base at each pole ( Figs 8, 9 ); occellus at summit ( Fig. 12 ). Valve face lanceolate bordered by well-developed marginal ridge ( Fig. 10 ) separating it from a deep mantle with distinctly pronounced apices ( Fig. 11 ). Two long outwardly directed hollow spines, exterior openings of rimoportulae positioned diagonally between elevations and valve centre. Narrow annulus extending apically between rimoportulae ( Figs 11–13 ). Areolae loculate with internal foramina. Biseriate rows of fine pores externally between barely raised costae on mantle; on valve face in a more irregular arrangement of fine pores between scattered spinules transapically meeting at a narrow sternum (see also Ashworth et al. 2013: fig. 4b, e).

Observations:— The description above is based on material from Bonny River, Nigeria (BM).

Figures

FIGURES 8–13. Trieres regia (M.Schultze) Ashworth & E.C. Theriot (Bonny River, Nigeria). Fig. 8. Reproduction of illustrations for Denticella regia from Schultze (1859: figs 11 and 12) (not to scale). Fig. 9. Valve exterior tilted, apices with narrow outwardly directed elevations, broad mantle narrowing to acute apices and marginal ridge extending between elevations; scale bar = 43 μm. Fig. 10. Valve face fractured showing loculate areolae and scattered spinules on face and mantle; scale bar = 2 μm. Fig. 11. Valve flat with lanceolate valve face, semi-lanceolate mantle and narrow annulus (sternum) extending just beyond hollow spines, which are the openings from rimoportulae; scale bar = 38 μm. Fig 12. Elevation with small flat summit and ocellus on distal face; scale bar = 2.5 μm. Fig. 13. Detail of narrow annulus (arrow) (sternum) bordered by transapical rows of poroids; scale bar = 7.5 μm.