Echiurans are marine worms whose bodies are not segmented. They have an extensible proboscis and a set of small hooks at the posterior end. There are about 150 species, mostly inhabiting warm shallow seas and burrowing in the soft sediment.
Sites 2
- Introduction to the Echiura Introduction to this small phylum, closely related to the Annelids, from UCMP Berkeley.
- Echiura Wikipedia article on this group of marine worms that burrow into mud or sand or live in empty shells.