Serpentes see Suborder Serpentes Linnaeus, 1758
   Alethinophidia Nopcsa, 1923 see Infraorder Alethinophidia Nopcsa, 1923
     Henophidia Hoffstetter, 1939 [paraphyletic] see Parvorder Henophidia Hoffstetter, 1939
       1.1 Family Aniliidae Stejneger, 1907 [monotypic] - cylinder snakes
       1.2 Family Tropidophiidae Brongersma, 1951
       2.1.1.1.1 Family Calabariidae Gray, 1858 [monotypic]
       2.1.1.1.2 Family Candoiidae Pyron, Reynolds & Burbrink, 2014
       2.1.1.2.1 Family Sanziniidae Romer, 1956
       2.1.1.2.2.1 Family Charinidae Gray, 1849
       2.1.1.2.2.2.1 Family Erycidae Bonaparte, 1831
       2.1.1.2.2.2.2 Family Boidae Gray, 1825 - pythons and boas
       2.1.2.1.1 Family Cylindrophiidae Fitzinger, 1843 [paraphyletic] - Asian pipe snakes
       2.1.2.1.1.n Family Anomochilidae Cundall, Wallach & Rossman, 1994 [monotypic] - dwarf pipe snakes
       2.1.2.1.2 Family Uropeltidae Müller, 1831 - shield-tail snakes
       2.1.2.2.1 Family Xenopeltidae Bonaparte, 1845 [monotypic] - sunbeam snakes
       2.1.2.2.2.1 Family Loxocemidae Cope, 1861 [monotypic]
       2.1.2.2.2.2 Family Pythonidae Fitzinger, 1826
       2.2.1.1 Family Bolyeridae see Family Bolyeriidae Hoffstetter, 1946
       2.2.1.2 Family Xenophidiidae Wallach & Günther, 1998 [monotypic]