(from a privative, and κατάρισμα, I sweep), an ancient kind of mosaic pavement composed of coloured pebbles. The most celebrated was that at Pergamus, executed by Sosus, which exhibited the appearance of an unswept floor after a banquet, whence the chamber was called ἀκαπνοῦσα ὁδός. The central part represented several doves sitting on the edge of a caudarius, and the image of one in the act of drinking was reflected in the water. An imperfect copy of this central group was found at Tivoli in 1737, and another, in better preservation, was discovered at Naples in 1833.—See Plan. xxxvi. 25.