Systematic studies on acritarchs of Ordovician, Silurian and Devonian ages of North Africa, the British Isles and Podolia showed varieties of six types of wall structures and five types of excystment mechanism. These are well documented in this study and may form the main basis for a natural classification in future work.
- Received February 1, 1984.
- Revision received February 1, 1986.
- © 1986 The Micropalaeontological Society