Cryptoglena pigra. Although Cryptoglena has been considered a euglenid flagellate the genus should probably be considered of uncertain affinity. The cells are solitary and have a single emergent flagellum slightly longer than the cell body. The cell body is rigid, dorsoventrally flattened and ovoid in outline with rounded anterior and bluntly pointed posterior. There is an obvious longitudinal furrow seen well in this image. Described as having one or two laminate parietal chloroplasts without pyrenoids. The posterior nucleus is not visible in this image. The prominent anterior stigma is seen well here. The genus has been described as monospecific by some authors and as containing five or six species by others. From a slow flowing freshwater stream near Boise, Idaho. Differential interference contrast illumination.
