Features Pollocks's innovative, user-friendly keys that circumvent many of the difficulties of traditional identification systems. Pollock's keys - in part developed while he was at Woods Hole Marine Biological Laboratory - offer choices among distinctive attributes of the specimen. Results are compared to all variations found in the region's fauna, using a neatly displayed tabular form accompanied by many line drawings. The introduction describes marine habitats, tips for conducting fieldwork, and outlines groups of organisms found in northeastern North America, from Nova Scotia to North Carolina. A handy guide for the non-expert, and essential for anyone conducting biotic surveys and advanced studies in the region.