Assertion: octopus's shell | /r/CapableOf | characterize bivalve
Facets:
Source sentences:
text: Octopuses completely lack the shell which characterizes more distant mollusc relatives like the snails and bivalves, but they have the same basic body design: a head with eyes; muscular foot (modified into eight arms); and a sac-like body mass that encloses the internal organs and gill chamber.