Trieres sinensis (Greville) Ashworth and 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 : 6-10

Trieres sinensis (Greville) Ashworth and E.C. Theriot ( Figs 14–20 )

Basionym:— Biddulphia (‘Chinesis’) sinensis Greville (1866: 81 , pl. 9, fig. 16)

Synonyms:— Odontella (‘Chinesis’) sinensis (Greville) Grunow (1884: 58) Denticella sinensis (Greville) De Toni (1894: 884) Zygoceros chinensis (Greville) Cleve (1901: 31)

Type:— “Harbour of Hong Kong; J. Linton Palmer, Esq.” ( Greville 1866: 81) ( BM 2998, syntypes, see Williams 1988: 18).

B.” in Bailey (1851: figs 34 and 35) (not to scale).

Frustules in girdle view rectangular with short tubular elevations at apices and long, tubular spine at base. Apical axis 90–260μm, transapical 60–80 μm, areolae 16–18 in 10 μm (after Hendey 1964, Hasle & Syvertsen 1996). Valve broadly lanceolate with rounded apices and short tubular elevations at each pole with ocellus at summit ( Figs 14, 15, 19 ). Valve face narrowly lanceolate bordered by narrow marginal ridge separating valve face from distinctly expanded mantle ( Fig. 14 ). At base of each elevation lies an outwardly directed tubular spine lying on a raised base ( Fig. 15 ), exterior opening of rimoportula ( Fig. 18 ). Areolae loculate, mantle exterior with bi- and tri-seriate rows of fine pores bordered by barely raised costae that span entire depth of mantle ( Figs 16. 17 ). On valve face in similar pattern, in transverse rows, those at pole broken by central sternum extending ¼ length of valve face ( Fig. 20 ). Circular pores with raised rims scattered over valve face and mantle ( Fig. 16 ).

Observations:— Lavigne et al. (2016: 320–324) provide images of the living cell with ‘small discoid chloroplasts’ ( Lavigne et al. 2016: figs 85–90). For further details on this species see Ashworth et al. (2013: fig. 4c, f).

The description above is based on material from “Wunderluss” (locality unknown, ex Brigger colln, BM).

Figures

FIGURES 14–20. Trieres sinensis (Greville) Ashworth & E. C. Theriot (“Wunderluss”, locality unknown ex Brigger colln, BM). Fig. 14. Oval valve with narrow valve face and parallel margins extending almost to apices and broad semi-lanceolate mantle; scale bar = 10 μm. Fig. 15. Valve tilted with short narrow apical elevations, a long spine at its base; scale bar = 10 μm. Fig. 16. Valve centre with irregular pattern of poroids and occasional circular pores, probably the bases of hollow spinules; scale bar = 1 μm. Fig. 17. Quadrangular-hexagonal locular walls with external transapical rows of poroids meeting a short annulus at valve centre; scale bar = 1 μm. Fig. 18. Elevation with ocellus on summit and forked opening of hollow spine (rimoportula); scale bar = 10 μm. Fig. 19. Ocellus with margin of small triangular spines; scale bar = 1 μm. Fig. 20. Short annulus (arrow) (sternum) extending from base of hollow spine; scale bar = 2 μm.