of it were found at the villa at Hartlip, when re-opened a few years ago; it is also met with at the villa at Bignor in Sussex; and a block of it lies within the walls of Richborough Castle, which was probably taken there by the Romans. The late Dr. Buckland, on a slight examination of a piece which he broke off this last mentioned specimen, said he believed it came from the neighbourhood of Weymouth.