Abstract
A strain of Pedinella hexacostata Vysotskii (Chrysophyceae, or Chrysomonadida) was grown in culture and examined by light and electron microscopy. Behaviour, phagotrophy and division have been observed and salinity tolerance tested experimentally. Pedinella is discussed with relation to Pseudopedinella and other members of the Pedinellaceae. The fine structure of the tentacles is compared with that of tentacles in some other Protozoa.