Figs 15-19. Besa papillaeformis, topotype material (Setchell #6485, UC173490). Longitudinal sections through spermatangial thalli. Figs 15-16. Surface cells dividing by concavo-convex division into spermatangial parent cells. Figs 17-18. Branched spermatangial parent cells. Fig. 19. Elongate spermatangial parent cells with terminal spermatangia.