Figs 31–34.

Maryna umbrellata, TEM micrographs of resting cysts. 31, 32 – overview and wall detail of bismuth stained sections. The wall is about 8 μm thick and consists of two conspicuous zones: the pericyst with glass granules and the thick, laminated mesocyst. The arrow in Fig. 32 marks a minute space between endocyst and ciliate cortex. The cyst contents is dominated by white-spotted “spongy globules,” which become very conspicuous at higher magnification (see Fig. 53); 33, 34 – overview and wall detail of unstained sections after protease digestion. Both the mesocyst of the cyst wall and the cyst contents appear light grey due to the digestion of proteins, while the ectocyst and the basal layer of the pericyst are as in Fig. 32, i.e., contain no or very few protein. The narrow space (asterisk) between ectocyst and basal layer is a shrinkage artifact. BL – basal layer, C – ciliate cortex, E – endocyst, EC – ectocyst, G – glass layer, M – mesocyst, MA – macro-nucleus, W – cyst wall. Scale bars: 1 μm (Fig. 32), 3 μm (34), and 40 μm (31, 33).