FIGURES 3–8 in Stephanodiscus Ehr. species from Holocene sediments in the Faiyum Depression (Middle Egypt)

FIGURES 3–8. Stephanodiscus neoaegypticus, LM. Fig. 3. Valve showing an indistinct sub-marginal hyaline ring and broad interfascicular ribs. Fig. 4. Valve focused to show the valve face-mantle zone with occasional bifurcating interfascicular ribs (arrowed). Fig. 5. A strongly silicified valve. Fig. 6. A part dissolved valve with eroded margin and diminished interfascicular ribs. Figs 7–8. S. neoaegypticus v. fekrii LM. Fig. 7. Whole valve focused to show the broad interfascicular ribs and marginal bifurcations (arrowed). Fig. 8. The same whole valve (Fig. 7) focused to show the central area. Scale bars = 5 µm (Figs 3–8)