FIGURE 8 in Three novel species of Bacillariophyta (Diatoms) in the genera Surirella and Thalassiosira from Pleistocene Paleolake Lorenyang (~2 - 1.6 Ma) Turkana Basin, Kenya

FIGURE 8. SEM Thalassiosira gassaea. Scanning electron micrographs of Thalassiosira gassaea. The exterior of the valve (A) is marked by sparse marginal fultoportulae and a single large rimoportula (arrowed). The interior of the valve exhibits a simple rimoportula with raised lips near the middle of the aperture and reduced near the outside ends of the aperture (D). The fultoportulae are slightly raised with four satellite pores, the areolae are marked with elliptical velum that are slightly depressed into interior valve surface. Internal views of the valve (B & C) show overall valve structure, rimoportula is closely associated with one fultoportula (B & D).