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.
Cephalic retractor muscle; glandular organ; Neotropical Region; taxonomy; Terricola
