FIGURES 69–72 in Systematics of araphid diatoms with asymmetric rimoportulae or densely packed virgae, with particular attention to Hyalosynedra (Ulnariaceae, Bacillariophyta)

FIGURES 69–72. Thalassionema cf. bacillare from culture HK361. 69. Whole valve. 70. Detail of apex, exterior view. 71. Detail of exterior of central area, where some areolae had a T- or Y-shaped bar. 72. Detail of internal area of apex showing subterminal rimoportula with slit aligned along apical axis.