This frequently updated Web site, individually hosted by Wolfgang Seifarth, is devoted to the study of polyclad flatworms, the free-living marine flatworms primarily found in tropical coral reefs. This comprehensive site describes every characteristic of this beautiful worm order -- phylogeny, anatomy, natural history, distribution, and much more. If you're of the opinion that all worms are impossibly disgusting, click on Marine Flatworms to view a collection of polyclad worm photos from around the globe; it should change your mind. Although not closely related to flatworms, the Web site features an extensive image gallery of colorful nudibranchs (aquatic slugs) that's also well worth the visit. This Web site also contains a Photo of the Week page and a list of marine biology and diving links.