Marine Phytoplankton: A Guide to Naked Flagellates and Coccolithophorids provides an introduction to marine planktonic flagellates. It emphasizes the biological and physical features that are needed to identify these species, and presents only those methods that are critical for this task while relying on other publications that have extensively covered general phytoplankton research methods. The book begins with an overview of marine planktonic organisms, describing their evolution and classification as well as the difficulties in identifying planktonic marine flagellates. The discussion then turns to marine planktonic flagellates, including Chromophyta, Chlorophyta, and zooflagellates (Phylum Zoomastigophora). It presents techniques used in flagellate studies, common flagellate synonyms, and an index of flagellate taxa. The chapter on modern coccolithophorids includes generic and species descriptions, a list of common coccolithophorid synonyms, and an index of coccolithophorid taxa. This text was written for serious plankton workers who seek to hone their skills in identifying marine flagellated species.