We inferred the phylogenetic relationships among 58 genera of Sericostom-atoidea, representing all previously accepted families as well as genera that were notplaced in established families. The analyses were based on ve fragments of the proteincoding genes carbamoylphosphate synthetase (CPSase of CAD), isocitrate dehydroge-nase (IDH), Elongation factor 1a (EF-1a), RNA polymerase II (POL II) and cytochromeoxidase I (COI). The data set was analysed using Bayesian methods with a mixedmodel, , and parsimony. The various methods generated slightly different resultsregarding relationships among families, but the shared results comprise support for: (i)a monophyletic Sericostomatoidea; (ii) a paraphyletic Parasericostoma due to inclusionof Myotrichia murina, leading to synonymization of Myotrichia with Parasericostoma;(iii) a polyphyletic Sericostomatidae, which is divided into two families, Sericostom-atidae sensu stricto and Parasericostomatidae fam.n.; (iv) a polyphyletic Helicophidaewhich is divided into Helicophidae sensu stricto and Heloccabucidae fam.n.; ( v) hypoth-esized phylogenetic placement of the former incerta sedis genera Ngoya, Seselpsycheand Karomana; (vi) a paraphyletic Costora (Conoesucidae) that should be divided intoseveral genera after more careful examination of morphological data; (vii) reinstatementof Gyrocarisa as a valid genus within Petrothrincidae. A third family, Ceylanopsychi-dae fam.n., is established based on morphological characters alone. A hypothesis ofthe relationship among 14 of the 15 families in the superfamily is presented. A key tothe families is presented based on adults (males). Taxonomic history, diagnosis, habitatpreference and distribution data for all sericostomatoid families are presented.
2017. Vol. 42, 240-266 p.