Stones with two matching semi-circular pieces, resembling Japanese kamaboko (boiled fish paste), were called setsujo (semicylindrical sashes) according to the "Wamyo-sho", a dictionary compiled in the Heian Period.
蒲鉾を板ごと横に切ったような上円下方のものを櫛上（せつじょう）と呼んで（『和名抄』。