抄録
Rapana is one of the harmful: gastropods to oyster. It climbs up the poles and ropes of the hanging apparatus of oyster. To exterminate the enemy, I put a bur of chestnut on the rope which may be the path of the climbing Rapana. Rapana when climbs over the bur, the thorn of which pricks its soft foot, it cannot help drawing its foot in, as the result, it cannot go more and access to the oyster.
