Assertion: echinoderm's mouth | /r/AtLocation | the center of the undersurface
Facets:
Source sentences:
text: The mouth, located in the center of the undersurface, is surrounded by a thickened region bearing five pairs of short, heavy tube feet and sometimes five pairs of bushy gills.
text: The mouth, located in the center of the undersurface, is surrounded by a thickened region bearing five pairs of short, heavy tube feet and sometimes five pairs of bushy gills.