fossil marine animal genera Linnaeus, 1758 - animals Phylum Porifera Grant, 1836 - sponges 1 Class Demospongia see Class Demospongiae Sollas, 1885 2 Class Calcarea Bowerbank, 1864 - calcareous sponges 3 Class Hexactinellida Schmidt, 1870 - hexactinellids 4 Class †uncertain 5 †"archaeocyathids"