After excluding groups not related, the informal group Sigmurethra has become the suborder Helicina, with the following infraorders and a collection of families with no superfamily： Suborder Helicina Infraorder Arionoidei Infraorder Clausilioidei Infraorder Helicoidei: formed from Helicoidea Rafinesque, 1815 and Sagdoidea Pilsbry, 1895 Infraorder Limacoidei: formed from original limacoid clade Infraorder OleacinoideiOleacinoidea: formed from original Testacelloidea but with the family Testacellidae excluded; Haplotrematoidea: formed from original Rhytidoidea and Haplotrematidae Infraorder Orthalicoidei Infraorder Pupilloidei Infraorder Rhytidoidei: formed by Rhytidoidea merging with contents from Acavoidea. Wikipedia