Kingdom Animalia Linnaeus, 1758 - animals Phylum Porifera Grant, 1836 - sponges Class Calcarea Bowerbank, 1864 - calcareous sponges Subclass Calcaronea Bidder, 1898 Order Lithonida Döderlein, 1892 1 Family Minchinellidae Dendy & Row, 1913 2 Family Petrobionidae Borojevic, 1979 [monotypic]