Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Heterobranchia Burmeister, 1837 [monotypic] see Superorder Heterobranchia Burmeister, 1837 Order Heterostropha Fischer, 1885 Superfamily Architectonicoidea Gray, 1850 Family Architectonicidae Gray, 1850 Genus Heliacus d'Orbigny, 1842 Subgenus Teretropoma Rochebrune, 1881