Assertion: echinoderm's arm | /r/CapableOf | merge to central disk
Facets:
value: gradually
type: MANNER
Source sentences:
text: Star-shaped or pentagonal; 5 or more arms merged gradually to central disk; endoskeleton flexible; ampullae (internal bulbous swelling associated with the external tube foot) single-lobed, bilobed in one species; short spines and pedicellariae.