Chordata Bateson, 1885 - chordates Count: - 1 Class Leptocardii Müller, 1845 [monotypic] see Subphylum Cephalochordata Owen, 1846 Count: [f] 1o;3f;1g 2 Class Marsipobranchii see Class Cyclostomata Richards Count: [f] 2o;4f 3 Class †Ostracophori Count: [†f] †5o;15f;7g;1s 4 Class †Arthrodira Woodward, 1891 - arthrodires see Order Arthrodiriformes Grande & Eastman, 1986 Count: [†f] †3o;9f;2g 5 Class Elasmobranchii Bonaparte, 1838 see Subclass Elasmobranchii Bonaparte, 1838 Count: [f†f] 7o;39f;5g; †4o;22f;4g 6 Class Pisces Linnaeus, 1758 see Superclass Pisces Linnaeus, 1758 Count: -