botany, a genus of the polyantria monogynia clas. The corolla has four petals; CHELONIUS Lapis, in natural-history, a stone said by the ancients to be found in the stomachs of young swallows, and greatly cried up for its virtues in the falling-sickness; but from their description, it appears to be only a species of lyodontes, or bufonite. See Lyodontes, and Bufonite.