Contents: Preface. 1. Fresh-water and terrestrial red algae. 2. Thermophilic and thermo-tolerant algae. 3. Snow and ice algae (cryovegetation) 4. Halophilic and halo-tolerant algae. 5. Acidophilic and acido-tolerant algae. 6. Soil algae/edaphophytes upon or inside the surface of the earth. 7. Terrestrial algae; subaerial algae; lithophytes and corticolous algae. 8. Parasitic algae. 9. Hydrophytic algae; planktonic algae. 10. Toxic algae. 11. Epizoic, endozoic symbiotic algae. 12. Algal dispersal. 13. Different water pollutants, pollution control and waste disposal. 14. Eutrophication, nutrient pollution. 15. Economic aspects and uses of the algae. 16. Problem and algae, negative aspects of algae. Photoplates showing some ecologically and economically important algae and the effect of water pollutants on the survival of algae. Index.