Redescription of two land planarian species of Notogynaphallia Ogren & Kawakatsu (Platyhelminthes, Tricladida, Geoplaninae) and confirmation of the heterogeneity of the genus

Notogynaphallia caissara (E.M. Froehlich, 1955) and N. fita (Froehlich, 1959) are redescribed. Both species are included in the so-called group 2 of E.M. Froehlich & Leal-Zanchet (2003), in Notogynaphallia, and are provided with a cephalic retractor muscle derived from the ventral longitudinal subepidermic muscle layer. A muscle retractor does not exist in the type-species of the genus. This is strong evidence of the morphological heterogeneity within the genus, as E.M. Froehlich & Leal-Zanchet (2003) previously proposed mainly based on characters of the reproductive organs.