Wikimedia
Wikipedia: Echinoderm
Wikipedia provides detailed information on echinoderms, or a phylum of marine animals including star fish and sea urchins. Website includes image, chart of scientific classification, and many hyperlinked terms.
A-Z Animals
A Z Animals: Animal Facts: Sea Slug (Holothuroidea)
Provides photographs and a fact card about the sea slug, also known as the sea cucumber. Discusses where they live, diet, predators, physical features, the different species, reproduction, and their value to humans.
California Academy of Sciences
California Academy of Sciences: Echinoderm Webpage
Resource provides a brief overview of echinoderms. Includes pictures and links for more information.