FINE STRUCTURE OF NAUTOCOCCUS MAMMILATUS (CHLOROCOCCALES, CHLOROPHYCEAE), A COCCOID ALGA WITH TOMENTOSE CELL WALLS1

The unusual morphology of the coccoid, neustonic alga Nautococcus mammilatus Korschikov prompted its study with the electron microscope. Ultrastructural features including a fibrous cell wall with definite periodicity and an external tomentum were observed. These and other features of the alga are compared with those of related, species, and the use of cell wall characteristics in taxonomy is discussed.