FIGURES 21–28 in Comparison of two new species of Mastogloia (Bacillariophyceae) with other small members of section Ellipticae

FIGURES 21–28. Mastogloia ovalis, SEM (DISVAR-ANS2SP17, Siladen, Indonesia). (21) External view of valve showing straight raphe branches; (22) External view of central region showing proximal raphe endings; (23) External view of tilted valve showing partectal pore (arrowhead); (24) Internal valve view showing well-marked bilobed partecta (arrowhead); (25) Internal view of central region showing proximal raphe endings; (26) Internal view of valve showing partecta with linear rows of fine pores; (27) Internal view of tilted valve showing partectal pores (arrowhead); (28) External view of tilted valve showing rounded areolae covered by tongue-like vela with horseshoe-shaped edges.