A complete, or nearly complete, pavement of opus sectile, that is, a pavement of variously shaped slabs of ornamental marbles laid in a pattern, is one of the rarest remains of classical antiquity. In the whole of Italy not a single complete pavement of that description is believed to exist, with the exception, of course, of the pavement of the Pantheon in Rome, and one or two insignificant examples at Pompeii; so that we have to judge of the extent to which the beauties of pattern, colour, and execution were carried in this class of decoration from remains seldom containing more than a few superficial feet, and consider ourselves fortunate that so much is left. A large and very fine piece has, it is true, been recently uncovered in the Forum of Nerva; but as it is at present unprotected from the weather and, moreover, used (with the permission of the municipality of Rome) as an asylum for stray cats, it will not be long before it is disintegrated by damp and frost.