Key to Superfamilies of ASCARIDOMORPHA

1 Lips absent, or markedly reduced and variable; mouth opening sometimes elongated dorso-ventrally; oesophagus short, simple and cylindrical, or short and divided into two portions having or not having same width; pharyngeal portion of oesophagus present or absent; pre-cloacal sucker may be present in male; less than 11 pairs of genital papillae in male...... Seuratoidea

- With three well defined lips, usually large, sometimes separated by interlabia; oesophagus simple and cylindrical or terminated by swelling without valves; intestinal caeca present or absent; pre-cloacal sucker absent in male; genital papillae in male numerous................................................................................. Ascaridoidea