Phoronida - Four photographs of the Horseshoe Worm, Phoronis hippocrepia.
Phoronida - Illustration of the internal anatomy of a horseshoe worm and a list of species.
Phoronida - Geographical distribution, systematics (including relationship to other lophophorates), list of species, scientific papers, links. Site is in English, Spanish, and French.
Phoronida World Database - Commonly known as horseshoe worms, this phylum is an exclusively marine group of lophophorate animals. Provides a searchable taxon tree.
Phoronis architecta - Information from Invertebrate Anatomy OnLine on this species and its classification, with a detailed account of its external anatomy and its actinotroch larva.
