Assertion: octopus's arm | /r/HasProperty | joined at their bases
Facets:
value: by a web of tissue
type: CAUSE
Source sentences:
text: The arms are joined at their bases by a web of tissue known as the skirt, at the centre of which lies the mouth.
text: Their arms are joined at their bases by a web of tissue that’s known as a skirt; their mouth is found in the center of the skirt and contains a pair of sharp beaks and a file-like organ known as a radula.