Trichrus3414 comes from Africa: it is of a black colour, but yields three different liquids, black at the lower part, blood-red in the middle, and of an ochre colour at the top. Thelyrrhizos3415 is of an ashy or russet colour, but white at the lower part. Thelycardios3416 is like a heart in colour, and is held in high esteem by the people of Persia, in which country it is found: the name given to it by them is “mulc.” Of thracia3417 there are three varieties; a green stone, one of a more pallid colour, and a third with spots like drops of blood. Tephritis3418 is crescent-shaped, with horns like those of the new moon, but it is of an ashy colour. Tecolithos3419 has all the appearance of an olive stone: it is held in no estimation as a gem, but a solution of it will break and expel urinary calculi.