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"Distinguished by their habit of forming a tube or case, within which the soft parts of the animal can be retracted. This tube is usually attached to stones or other submarine bodies. It is often composed of carious foreign materials, such as sand, small stones, and the debris of shells, lined internally with a smooth covering of hardened mucus." — Goodrich, 1859

Terebella medusa

"Distinguished by their habit of forming a tube or case, within which the soft parts of the animal can…

The terebella medusa, out of its case.

Terebella medusa out of its case

The terebella medusa, out of its case.