The purpose of this application, under Article 23.9.3, is to conserve the generic name Cylindrus Fitzinger, 1833 for a well-known, monotypic genus with a model species for Alpine endemism in gastropods. This name is threatened by the earlier Cochlopupa Jan, 1830, a virtually unused, objective synonym, and by two senior homonyms: the unused Cylindrus Batsch, 1789, and Cylindrus Deshayes, 1824 which is an unjustified emendation of Cylinder Montfort, 1810 and has occasionally been used, though incorrectly applied. Currently Cylinder Montfort, 1810 is in use for this taxon, despite being an objective junior synonym of Cylindrus Batsch, 1789. It is proposed that the names Cylindrus and Cylinder be conserved in their accustomed sense by the suppression of all usages of the name Cylindrus before that of Fitzinger, 1833, and of Cylinder before that of Montfort, 1810.

The purpose of this application, under Article 75.5 of the Code, is to set aside all type fixations for Nautilus pompilius Linnaeus, 1758, and to designate a neotype. The type series of N. pompilius includes specimens in the Linnean Society of London, the University Museum in Uppsala, and specimens figured by pre-Linnaean authors indicated by reference by Linnaeus (1758). The original material includes juveniles, specimens with unknown provenance, modified specimens and carved ornaments. Given the poor quality of the material and the lack of clarity as to its type status, we apply to the Commission asking to set aside all previous type fixations and designate a neotype. The neotype designation is of utmost importance for accurate identification of this species, which is necessary for its trade control and protection.

The purpose of this application, under Articles 23.9.3 and 81 of the Code, is to conserve the specific name Pomachilius variegatus Schwarz, 1904 (Insecta, Coleoptera, elateridae) by suppression of the name Aeolus variegatus Curtis, 1839 a senior secondary homonym, and a subjective junior synonym of Pomachilius subfasciatus (Germar, 1824). Stability of taxonomy and nomenclature would best be served by suppressing the senior homonym.

The purpose of this application, under Articles 23.9.3 and 81 of the Code, is to conserve the widely used name Cicindela varians Gory, 1833 (currently Cenothyla varians), a primary junior homonym of Cicindela varians Ljungh, 1799, for a species of carabid beetle. The senior homonym has been used only once after 1900, and is a subjective senior synonym of Cicindela scutellaris Say, 1823. Suppression of Cicindela varians Ljungh, 1799 would also help maintain the usage of the widely used name Cicindela scutellaris Say, 1823.

The purpose of this application, under Articles 70.3, 74.7 and 81.1 of the Code, is to conserve the current usage of the beetle genus Thorectes Mulsant, 1842 (Insecta, Coleoptera, scarabaeoidea, geotrupidae) by confirmation of its type species Scarabaeus laevigatus Fabricius, 1798. This action will also stabilise the predominant usage of another genus, Jekelius López-Colón, 1989, for a phylogenetically relatively distant clade of species whose ecological importance in Mediterranean Quercus forests is currently under study. A lectotype is designated for Scarabaeus laevigatus Fabricius, 1798.

The purpose of this application, under Article 23.9.3 of the Code, is to conserve the widely used generic name Dimetrodon Cope, 1878 (sphenacodontoidea, sphenacodontidae). The name Dimetrodon is threatened by its senior subjective synonym Bathygnathus Leidy, 1853. The name Dimetrodon has become widely accepted and is in prevailing usage. It is proposed that Dimetrodon be given precedence over Bathygnathus whenever these names are considered to be synonyms.

The purpose of this application, under Article 89.1.1 of the Code, is to promote universality in the interpretation of the notion ‘superspecies’ as used in Article 10.4 of the Code, particularly with respect to certain European land snails, by asking the Commission to rule that ‘Formenkreis’ (plural ‘Formenkreise’) is not a genus-group taxonomic rank with potential availability. According to Article 10.4 of the Code not all subdivisions of a genus are equal. A borderline exists between ‘section’ or ‘division’, both deemed to be subgenera, and a still lower level of taxa that are referred to with ‘a term such as superspecies’. The term ‘superspecies’ was introduced by Mayr (1931) as a gloss, for international use, of the German term ‘Artenkreis’, which itself was a replacement term for ‘Formenkreis’. This implies that a name proposed for a ‘Formenkreis’ should not be deemed to be a genus-group name.

Under the plenary power the Commission has conserved the species-group name Helix (Helicogena) aspersa insolida Monterosato, 1892 (currently Erctella insolida; Gastropoda, Pulmonata, helicidae) by suppressing Helix (Campylaea) insolida Brusina, 1876 and Helix (Campylaea) insolida Pfeiffer & Clessin, 1881.

Under the plenary power the Commission has emended the spelling of the names omaliidae Handlirsch, 1904 (Insecta, Archaeorthoptera) and xenopteridae Pinto, 1986 (Insecta, Megasecoptera). The stem of the generic name Omalia has been emended to Omalia- to give omaliaidae, and the stem of the generic name Xenoptera has been emended to Xenoptera- to give xenopteraidae.

Under the plenary power the Commission has conserved the specific name Habroleptoides confusa Sartori & Jacob, 1986 for a well-known European mayfly (family leptophlebiidae) by reversing precedence with the senior subjective synonym Habroleptoides carpatica Bogoescu & Crăsnaru, 1930, which has seldom been used since its first publication, while the junior synonym is very widely used.

The Commission has removed homonymy between the family-group names phycinae Swainson, 1838 (Osteichthyes, Gadiformes, phycidae) and phycinae Lyneborg, 1976 (Insecta, Diptera, therevidae) by emending the stem of the genus-group name Phycus Walker, 1850, on which the insect family-group name is based, and has changed the family-group name to phycusinae, leaving the fish family-group name, based on Phycis Walbaum, 1792, unaltered. The prevailing usage of Phycis Walbaum, 1792 has been conserved by setting aside all previous type species fixations and designating Blennius phycis Linnaeus, 1766 as the type species.

Under the plenary power the Commission has conserved the generic name Phoronis Wright, 1856 and the specific name Phoronis muelleri de Selys Longchamps, 1903 in their accustomed use by supressing the generic name Actinotrocha Müller, 1846 and the specific name branchiata Müller, 1846 (as published in the binomen Actinotrocha branchiata) for the purposes of the Principle of Priority.

Under the plenary power the Commission has conserved the specific name Coluber irregularis Leach in Bowdich, 1819 (currently Philothamnus irregularis) for the African northern green bush snake placed on the Official List by a ruling in Opinion 328, by ruling that it is not invalid by reason of being a junior primary homonym of Coluber irregularis Bechstein, 1802 (currently Boiga irregularis), used for the brown tree snake, known from Indonesia, Australia, Papua New Guinea, Melanesia and Guam.