“Scanning electron micrographs of the discs of the tube feet of Odontaster validus revealed varying degrees of concavity.”

“The labial surfaces of the plates are smooth, slightly convex both mesially and distally with a shallow concavity between.”

“Then the T wave becomes broad and the ST segment elevates, losing its normal concavity.”

“Design features rounded edges and concaveness, to promote tight sealing.”

“The shape of Taormina is a geometry of interlocking and contrapuntal curves and concavities with various centres and focal points.”

“There are usually no holes all the way through but lots of protuberances and concavities.”

“These are broad concavities in the ambitus that could be considered precursors to the ambulacral notches of certain mellitids.”