Assertion: oyster's shell | /r/HasProperty | small
Facets:
value: in most surface-burrowing species
type: OTHER
Source sentences:
text: It has an internal shell which is small (about 1 in or 24 mm) but very light and buoyant.
text: In most surface-burrowing species (the hypothetical ancestral habit) the shells are small, spherical or oval, with equal left and right valves.