1. Phylum Echiuroidea

3. Phylum Echiuroidea (e-key-ur-oid'-ee-ah): These worms have an unsegmented body. Water is pumped through their U-shaped burrow causing food to be trapped in the mucus net at the opening of the burrow.   

5. A scale worm, goby fish, and pea crab are commensal organisms that live in the burrow with this worm, which is the basis for its common name, Innkeeper Worm.

7. They seem to be closely related to annelids because they show segmentation during the larval stage but not as an adult
Feed with a proboscis
Usually 1-6 cm
Obscure phylum …..only marine

9. SAUSAGE WORM, Lissomyema mellita, a red blooded fat unsegmented worm-like creature, and gets its species name Mellita from living in dead sand dollars. Sometimes found boring into rock. Size 1/4-1 inch long.