Assertion: mussel's shell | /r/HasProperty | smooth
Facets:
Source sentences:
text: The shell is smooth with a sculpturing of fine concentric growth lines but no radiating ribs.
text: They have a smooth shell with a concentric line pattern and, like all bivalve mollusks, they are joined by a ligament at one edge.
text: The shells of the most efficient burrowers, the razor clams Ensis and Solen, are laterally compressed, smooth, and elongated.