GEOGCS["Unknown datum based upon the Plessis 1817 ellipsoid (deprecated)",
    DATUM["Not_specified_based_on_Plessis_1817_ellipsoid",
        SPHEROID["Plessis 1817",6376523,308.64,
            AUTHORITY["EPSG","7027"]],
        AUTHORITY["EPSG","6027"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,
        AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4027"]]