• Cryptoglena;
  • chloroplast;
  • Euglenophyceae


The taxonomic status of Cryptoglena pigra Ehrb., interpreted from observations based on bright-field microscopy, has been uncertain. Examination with the electron microscope of a clone of C pigra isolated by E. G. Pringsheim reveals certain features which, collectively, are distinctly euglenoid: periplast associated with muciferous bodies and subpellicular microtubules; canal and reservoir with microtubules; one flagellum with a swelling and emergent through a canal, and a second flagellum without a swelling and nonremergent; stigma (eyetpot) closely apprrssed to but not part of the chloroplast; nucleus with permanently condensed chromosomes attached to the inner nuclrar membrane; mitochondria with disc-shaped cristae constricted at the base; chloroplast with thylakoids often in triplets; and paramylon grains in the cytoplasm. Unlike most euglenoids, C. pigra possesses a single chloroplast that in transverse thin sections is U-shaped.