Order Testudines Wagler, 1830 - turtles Suborder Cryptodira Cope, 1868 Superfamily Testudinoidea Batsch, 1788 Family Emydidae Rafinesque, 1815 - pond turtles Subfamily Deirochelyinae Agassiz, 1857 Genus Graptemys Agassiz, 1857 Graptemys nigrinoda Cagle, 1954 - black-knobbed map turtle 1 Graptemys nigrinoda nigrinoda Cagle, 1954 - northern black-knobbed map turtle 2 Graptemys nigrinoda delticola Folkerts & Mount, 1969 - southern black-knobbed map turtle