FIGURE 21–28. Sceptronema orientale. SEM. Sample LPC 11650. Internal views. Figs 21, 23 in The epizoic marine diatom Sceptronema orientale (Licmophoraceae, Licmophorales): epitypification and emendation of specific and generic descriptions

FIGURE 21–28. Sceptronema orientale. SEM. Sample LPC 11650. Internal views. Figs 21, 23. Head-poles showing apical slit field on the valve mantle. Figs 22, 24. Foot-poles showing apical slit field on the valve mantle and several rimmed, sessile rimoportulae (arrowheads). Fig. 25. Rows of rimoportulae near each valve margin. Note rimoportulae are inserted within the striae (arrowheads). Fig. 26. Apical slit field on the head-pole. Fig. 27. Foot-pole of the valve of fig. 16. Note valvocopula in internal view and the next copula in external and internal view (VC valvocopula, CP 1 1st copula). Fig. 28. Head-pole of the valve of fig. 16 showing valvocopula with a very short septum formed on the