Fishes Class Actinopterygii Woodward, 1891 - ray-finned fishes Order Osteoglossiformes Berg, 1940 - bonytongues 1 Family Osteoglossidae Bonaparte, 1845 - bonytongues and arapaimas 2 Family Pantodontidae Peters, 1876 3 Family Hiodontidae Cuvier & Valenciennes, 1846 - mooneyes 4 Family Notopteridae Bleeker, 1851 - knifefishes 5 Family Mormyridae Bonaparte, 1831 - elephantfishes 6 Family Gymnarchidae Bleeker, 1859