FIGURES 20–25 in Aulacoseira principissa sp. nov., a new 'centric' diatom species from the sub- Antarctic region

FIGURES 20–25: SEM images of Aulacoseira principissa. All pictures taken from the holotype population (sample BW390). Fig. 20: Valve view of a linking valve with marginal ring of spines and regular areolae pattern. Fig. 21: Valve view of a linking valve with marginal ring of spines but irregular areolae pattern showing only open areolae near the valve margin. Fig. 22: Separation valve lacking linking spines. Fig. 23: Inside view with the narrow Ringleiste. Fig. 24: Detail of a broken valve part with the Ringleiste and the (eroded) rimoportula (see arrow). Fig. 25: Detail of a fragment showing vela from the inside. Scale bars represent 1 µm.