WoRMS taxon details
Flabellina McMurtrie, 1831
138019 (urn:lsid:marinespecies.org:taxname:138019)
accepted
Genus
Doris affinis Gmelin, 1791 accepted as Flabellina affinis (Gmelin, 1791) (type by monotypy)
Calmella Eliot, 1906 · unaccepted > junior subjective synonym
Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017 · unaccepted > junior subjective synonym
Costaea Tiberi, 1881 · unaccepted > junior objective synonym
Jojenia Aradas, 1847 · unaccepted
Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017 · unaccepted > junior subjective synonym
- Species Flabellina affinis (Gmelin, 1791)
- Species Flabellina alternata Ortea & Espinosa, 1998
- Species Flabellina bandeli (Ev. Marcus, 1976)
- Species Flabellina cavolini (Vérany, 1846)
- Species Flabellina enne (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
- Species Flabellina evelinae Edmunds, 1989
- Species Flabellina funeka Gosliner & R. J. Griffiths, 1981
- Species Flabellina gabinierei (Vicente, 1975)
- Species Flabellina gaditana (Cervera, García-Gómez & F. J. García, 1987)
- Species Flabellina ilidioi Calado, Ortea & Caballer, 2005
- Species Flabellina ischitana Y. Hirano & T. E. Thompson, 1990
- Species Flabellina pellucida (Alder & Hancock, 1843)
- Species Flabellina rubromaxilla Edmunds, 2015
- Species Flabellina abei (Baba, 1987) accepted as Coryphella abei Baba, 1987
- Species Flabellina albomaculata Pola, Carmona, Calado & Cervera, 2014 accepted as Edmundsella albomaculata (Pola, Carmona, Calado & Cervera, 2014)
- Species Flabellina albomarginata (M. C. Miller, 1971) accepted as Coryphellina albomarginata (M. C. Miller, 1971) (unaccepted > superseded combination)
- Species Flabellina alisonae Gosliner, 1980 accepted as Flabellina bicolor (Kelaart, 1858) accepted as Samla bicolor (Kelaart, 1858)
- Species Flabellina amabilis Y. Hirano & Kuzirian, 1991 accepted as Coryphella amabilis (Y. Hirano & Kuzirian, 1991) (original combination)
- Species Flabellina angelvaldesi (Millen & Hermosillo, 2012) accepted as Unidentia angelvaldesi Millen & Hermosillo, 2012
- Species Flabellina arveloi Ortea & Espinosa, 1998 accepted as Coryphellina arveloi (Ortea & Espinosa, 1998)
- Species Flabellina athadona (Bergh, 1875) accepted as Occidenthella athadona (Bergh, 1875) accepted as Coryphella athadona Bergh, 1875
- Species Flabellina babai Schmekel, 1972 accepted as Luisella babai (Schmekel, 1972)
- Species Flabellina baetica García-Gómez, 1984 accepted as Baenopsis baetica (García-Gómez, 1984) (original combination)
- Species Flabellina bertschi Gosliner & Kuzirian, 1990 accepted as Edmundsella bertschi (Gosliner & Kuzirian, 1990)
- Species Flabellina bicolor (Kelaart, 1858) accepted as Samla bicolor (Kelaart, 1858)
- Species Flabellina bilas Gosliner & Willan, 1991 accepted as Samla bilas (Gosliner & Willan, 1991)
- Species Flabellina borealis (Odhner, 1922) accepted as Gulenia borealis (Odhner, 1922) accepted as Coryphella borealis Odhner, 1922
- Species Flabellina browni (Picton, 1980) accepted as Fjordia browni (Picton, 1980) accepted as Coryphella browni Picton, 1980
- Species Flabellina bulbosa Ortea & Espinosa, 1998 accepted as Luisella bulbosa (Ortea & Espinosa, 1998) (unaccepted > superseded combination)
- Species Flabellina californica (Bergh, 1904) accepted as Coryphella californica Bergh, 1904
- Species Flabellina capensis (Thiele, 1925) accepted as Fjordia capensis (Thiele, 1925) accepted as Coryphella capensis Thiele, 1925
- Species Flabellina cerverai M. A. Fischer, van der Velde & Roubos, 2007 accepted as Coryphella cerverai (M. A. Fischer, van der Velde & Roubos, 2007) (unaccepted > superseded combination)
- Species Flabellina confusa Gonzalez-Duarte, Cervera & Poddubetskaia, 2008 accepted as Flabellina gaditana (Cervera, García-Gómez & F. J. García, 1987)
- Species Flabellina cooperi (T. D. A. Cockerell, 1901) accepted as Coryphella cooperi T. D. A. Cockerell, 1901
- Species Flabellina cynara (Ev. Marcus & Er. Marcus, 1967) accepted as Kynaria cynara (Ev. Marcus & Er. Marcus, 1967)
- Species Flabellina dana Millen & Hamann, 2006 accepted as Coryphella dana (Millen & Hamann, 2006) (unaccepted > superseded combination)
- Species Flabellina delicata Gosliner & Willan, 1991 accepted as Coryphellina delicata (Gosliner & Willan, 1991)
- Species Flabellina dushia (Ev. Marcus & Er. Marcus, 1963) accepted as Edmundsella dushia (Ev. Marcus & Er. Marcus, 1963) (unaccepted > superseded combination)
- Species Flabellina engeli Ev. Marcus & Er. Marcus, 1968 accepted as Luisella engeli (Ev. Marcus & Er. Marcus, 1968) (unaccepted > superseded combination)
- Species Flabellina exoptata Gosliner & Willan, 1991 accepted as Coryphellina exoptata (Gosliner & Willan, 1991)
- Species Flabellina falklandica (Eliot, 1907) accepted as Itaxia falklandica (Eliot, 1907) accepted as Coryphella falklandica Eliot, 1907
- Species Flabellina fisheri (MacFarland, 1966) accepted as Orienthella piunca (Er. Marcus, 1961) accepted as Coryphella piunca Er. Marcus, 1961
- Species Flabellina flamma (Ekimova, Deart, Antokhina, Mikhlina & Schepetov, 2022) accepted as Coryphellina flamma Ekimova, Deart, Antokhina, Mikhlina & Schepetov, 2022
- Species Flabellina fogata Millen & Hermosillo, 2007 accepted as Coryphella fogata (Millen & Hermosillo, 2007)
- Species Flabellina fusca (O'Donoghue, 1921) accepted as Himatina trophina (Bergh, 1890) accepted as Coryphella trophina (Bergh, 1890)
- Species Flabellina goddardi Gosliner, 2010 accepted as Pacifia goddardi (Gosliner, 2010)
- Species Flabellina gracilis (Alder & Hancock, 1844) accepted as Microchlamylla gracilis (Alder & Hancock, 1844) accepted as Coryphella gracilis (Alder & Hancock, 1844)
- Species Flabellina hamanni Gosliner, 1994 accepted as Coryphellina hamanni (Gosliner, 1994)
- Species Flabellina ianthina Angas, 1864 accepted as Pteraeolidia ianthina (Angas, 1864) (original combination)
- Species Flabellina indica (Bergh, 1902) accepted as Coryphellina indica (Bergh, 1902)
- Species Flabellina inornata A. Costa, 1866 accepted as Spurilla neapolitana (Delle Chiaje, 1841)
- Species Flabellina insolita García-Gómez & Cervera, 1989 accepted as Coryphella insolita (García-Gómez & Cervera, 1989) (unaccepted > superseded combination)
- Species Flabellina iodinea (J. G. Cooper, 1863) accepted as Flabellinopsis iodinea (J. G. Cooper, 1863)
- Species Flabellina islandica (Odhner, 1937) accepted as Chlamylla islandica (Odhner, 1937) (unaccepted > superseded combination)
- Species Flabellina japonica (Volodchenko, 1941) accepted as Ziminella japonica (Volodchenko, 1941)
- Species Flabellina lineata (Lovén, 1846) accepted as Fjordia lineata (Lovén, 1846) accepted as Coryphella lineata (Lovén, 1846)
- Species Flabellina llerae Ortea, 1989 accepted as Luisella llerae (Ortea, 1989) (unaccepted > superseded combination)
- Species Flabellina lotos (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017) accepted as Coryphellina lotos Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017
- Species Flabellina macassarana Bergh, 1905 accepted as Samla macassarana (Bergh, 1905) (unaccepted > superseded combination)
- Species Flabellina marcusorum Gosliner & Kuzirian, 1990 accepted as Coryphellina marcusorum (Gosliner & Kuzirian, 1990)
- Species Flabellina newcombi Angas, 1864 accepted as Facelina newcombi (Angas, 1864) (original combination)
- Species Flabellina nobilis (A. E. Verrill, 1880) accepted as Borealea nobilis (A. E. Verrill, 1880) accepted as Coryphella nobilis A. E. Verrill, 1880
- Species Flabellina ornata Angas, 1864 accepted as Austraeolis ornata (Angas, 1864) (unaccepted > superseded combination)
- Species Flabellina pallida (A. E. Verrill, 1900) accepted as Coryphella pallida A. E. Verrill, 1900
- Species Flabellina parva (M. Hadfield, 1963) accepted as Chlamylla parva (M. Hadfield, 1963) (unaccepted > superseded combination)
- Species Flabellina pedata (Montagu, 1816) accepted as Edmundsella pedata (Montagu, 1816)
- Species Flabellina poenicia (Burn, 1957) accepted as Coryphellina poenicia (Burn, 1957)
- Species Flabellina polaris (Volodchenko, 1946) accepted as Chlamylla polaris (Volodchenko, 1946) (unaccepted > superseded combination)
- Species Flabellina pricei (MacFarland, 1966) accepted as Apata pricei (MacFarland, 1966)
- Species Flabellina pseudoverrucosa (Martynov, Sanamyan & Korshunova, 2015) accepted as Coryphella pseudoverrucosa Martynov, Sanamyan & Korshunova, 2015
- Species Flabellina riwo Gosliner & Willan, 1991 accepted as Samla riwo (Gosliner & Willan, 1991)
- Species Flabellina rubrolineata (O'Donoghue, 1929) accepted as Coryphellina rubrolineata O'Donoghue, 1929
- Species Flabellina rubropurpurata Gosliner & Willan, 1991 accepted as Launsina rubropurpurata (Gosliner & Willan, 1991) (unaccepted > superseded combination)
- Species Flabellina salmonacea (Couthouy, 1838) accepted as Ziminella salmonacea (Couthouy, 1838)
- Species Flabellina sarsi (Friele, 1903) accepted as Borealea nobilis (A. E. Verrill, 1880) accepted as Coryphella nobilis A. E. Verrill, 1880
- Species Flabellina scolopendrella Risbec, 1928 accepted as Pteraeolidia semperi (Bergh, 1870) (unaccepted > junior subjective synonym)
- Species Flabellina semperi Bergh, 1870 accepted as Pteraeolidia semperi (Bergh, 1870) (unaccepted > superseded combination)
- Species Flabellina stohleri Bertsch & A. J. Ferreira, 1974 accepted as Flabellina telja Ev. Marcus & Er. Marcus, 1967 accepted as Luisella telja (Ev. Marcus & Er. Marcus, 1967)
- Species Flabellina telja Ev. Marcus & Er. Marcus, 1967 accepted as Luisella telja (Ev. Marcus & Er. Marcus, 1967) (unaccepted > superseded combination)
- Species Flabellina trilineata (O'Donoghue, 1921) accepted as Orienthella trilineata (O'Donoghue, 1921) accepted as Coryphella trilineata O'Donoghue, 1921
- Species Flabellina triophina [sic] accepted as Himatina trophina (Bergh, 1890) accepted as Coryphella trophina (Bergh, 1890) (incorrect subsequent spelling)
- Species Flabellina trophina (Bergh, 1890) accepted as Himatina trophina (Bergh, 1890) accepted as Coryphella trophina (Bergh, 1890)
- Species Flabellina vansyoci Gosliner, 1994 accepted as Edmundsella vansyoci (Gosliner, 1994)
- Species Flabellina verrucicornis A. Costa, 1867 accepted as Berghia verrucicornis (A. Costa, 1867) (original combination)
- Species Flabellina verrucosa (M. Sars, 1829) accepted as Coryphella verrucosa (M. Sars, 1829)
- Species Flabellina versicolor A. Costa, 1866 accepted as Favorinus branchialis (Rathke, 1806) (unaccepted > junior subjective synonym)
- Species Flabellina verta (Ev. Marcus, 1970) accepted as Coryphella verta Ev. Marcus, 1970
marine, fresh, terrestrial
recent only
feminine
McMurtrie, H. (1831). The animal kingdom arranged in conformity with its organization by the Baron Cuvier. The Crustacea, Arachnides and Insecta by P. A. Latreille. Translated from the French, with notes and additions. Vol. 2. G. 1C. 1H. Carvill, New York, xv 1 475 pp 1 10 pls., available online at https://www.biodiversitylibrary.org/page/28835332
page(s): 343 [details]
page(s): 343 [details]
Nomenclature Burn (2018) established that the name Flabellina was first established by McMurtrie in the first English edition of...
Nomenclature Burn (2018) established that the name Flabellina was first established by McMurtrie in the first English edition of Cuvier's Règne Animal. The name Flabellina had earlier been attributed by ICZN Opinion 781 to Voigt (1834), in the German edition of Cuvier's work; and later to Gray (1833) in Griffith & Pidgeon's translation of the same work. [details]
MolluscaBase eds. (2026). MolluscaBase. Flabellina McMurtrie, 1831. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=138019 on 2026-07-08
Date
action
by
The webpage text is licensed under a Creative Commons
Attribution 4.0 License
Nomenclature
original description
McMurtrie, H. (1831). The animal kingdom arranged in conformity with its organization by the Baron Cuvier. The Crustacea, Arachnides and Insecta by P. A. Latreille. Translated from the French, with notes and additions. Vol. 2. G. 1C. 1H. Carvill, New York, xv 1 475 pp 1 10 pls., available online at https://www.biodiversitylibrary.org/page/28835332
page(s): 343 [details]
original description (of Jojenia Aradas, 1847) Aradas A. (1847). Memorie di Zoologia Siciliana. Memoria III. Descrizione di alcuni molluschi nudi della Sicilia. <i>Atti dell'Accademia Gioenia di Scienze Naturali</i>, (2)4: 107-122, pl. 1, available online at http://biodiversitylibrary.org/page/7997965
page(s): 118 [details]
original description (of Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017) Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). <em>ZooKeys.</em> 717: 1-139., available online at https://zookeys.pensoft.net/articles.php?id=21885 [details]
original description (of Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017) Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). <em>ZooKeys.</em> 717: 1-139., available online at https://zookeys.pensoft.net/articles.php?id=21885 [details]
original description (of Calmella Eliot, 1906) Eliot, C. N. E. (1906). Notes on some British Nudibranchs. <em>Journal of the Marine Biological Association of the United Kingdom.</em> 7(03): 333., available online at https://doi.org/10.1017/s0025315400004355 [details]
original description (of Costaea Tiberi, 1881) Tiberi, N. (1881). I molluschi nudibranchi del Mediterraneo. <em>Bullettino della Società malacologica italiana.</em> 6: 182-264 ["1880"]., available online at https://www.biodiversitylibrary.org/page/38908108
page(s): 231 [details]
basis of record Burn R. (2018). <i>Flabellina</i> McMurtrie, 1831: The earliest valid Latinization?. <em>The Nautilus.</em> 132(1): 33-34. [details] Available for editors
[request]
page(s): 343 [details]
original description (of Jojenia Aradas, 1847) Aradas A. (1847). Memorie di Zoologia Siciliana. Memoria III. Descrizione di alcuni molluschi nudi della Sicilia. <i>Atti dell'Accademia Gioenia di Scienze Naturali</i>, (2)4: 107-122, pl. 1, available online at http://biodiversitylibrary.org/page/7997965
page(s): 118 [details]
original description (of Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017) Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). <em>ZooKeys.</em> 717: 1-139., available online at https://zookeys.pensoft.net/articles.php?id=21885 [details]
original description (of Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017) Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). <em>ZooKeys.</em> 717: 1-139., available online at https://zookeys.pensoft.net/articles.php?id=21885 [details]
original description (of Calmella Eliot, 1906) Eliot, C. N. E. (1906). Notes on some British Nudibranchs. <em>Journal of the Marine Biological Association of the United Kingdom.</em> 7(03): 333., available online at https://doi.org/10.1017/s0025315400004355 [details]
original description (of Costaea Tiberi, 1881) Tiberi, N. (1881). I molluschi nudibranchi del Mediterraneo. <em>Bullettino della Società malacologica italiana.</em> 6: 182-264 ["1880"]., available online at https://www.biodiversitylibrary.org/page/38908108
page(s): 231 [details]
basis of record Burn R. (2018). <i>Flabellina</i> McMurtrie, 1831: The earliest valid Latinization?. <em>The Nautilus.</em> 132(1): 33-34. [details] Available for editors
Taxonomy
status source
ICZN. (1966). Opinion 781. <i>Flabellina</i> Voigt, 1834 (Gastropoda): Placed on the Offcial List of Generic Names. <em>Bulletin of Zoological Nomenclature.</em> 23 (2-3): 104-105., available online at http://biodiversitylibrary.org/page/12222909
page(s): 104-105 [details]
status source Petit, R. E. & Coan., E. V. 2008. The molluscan taxa made available in the Griffith & Pidgeon (1833-1834) edition of Cuvier, with notes on the editions of Cuvier and on Wood's Index Testaceologicus. Malacologia 50: 219-264., available online at https://www.biodiversitylibrary.org/page/63536190
page(s): 222 [details]
page(s): 104-105 [details]
status source Petit, R. E. & Coan., E. V. 2008. The molluscan taxa made available in the Griffith & Pidgeon (1833-1834) edition of Cuvier, with notes on the editions of Cuvier and on Wood's Index Testaceologicus. Malacologia 50: 219-264., available online at https://www.biodiversitylibrary.org/page/63536190
page(s): 222 [details]
Other
additional source
Griffith, E. & E. Pidgeon. (1833 - 1834). The Mollusca and Radiata. Vol. 12,. <em>In: E. Griffith, [1824]−1835, The Animal Kingdom arranged in conformity with its organization, by the Baron Cuvier, [...]. London: Whittaker and Co.,.</em> viii + 601 pp., 61 pls. [Date of publication after Evenhuis (2009): pp. 1-384, Mollusca pls. 1−39, Zoophytes pls 1-20 - 1833; pp. viii + 385-601, Mollusca corrected pls. 28*, 36*, 37*, pls. 40-41 - 1834]., available online at http://www.biodiversitylibrary.org/item/40578
page(s): 40 [details]
additional source Voigt F.S. (1834) <i>In:</i> Cuvier G. (ed.). (1834). Das Thierreich, geordnet nach seiner Organisation, Als Grundlage der Naturgeschichte der Thiere und Einleitung in die vergleichende Anatomie. Vom Baron von Cuvier. vol. 3, die Mollusken. Leipzig, F. A. Brodhaus. 621 pp., available online at https://www.biodiversitylibrary.org/page/19175572
page(s): 124 [details]
page(s): 40 [details]
additional source Voigt F.S. (1834) <i>In:</i> Cuvier G. (ed.). (1834). Das Thierreich, geordnet nach seiner Organisation, Als Grundlage der Naturgeschichte der Thiere und Einleitung in die vergleichende Anatomie. Vom Baron von Cuvier. vol. 3, die Mollusken. Leipzig, F. A. Brodhaus. 621 pp., available online at https://www.biodiversitylibrary.org/page/19175572
page(s): 124 [details]
Present
Inaccurate
Introduced: alien
Containing type locality
From editor or global species database
Nomenclature Burn (2018) established that the name Flabellina was first established by McMurtrie in the first English edition of Cuvier's Règne Animal. The name Flabellina had earlier been attributed by ICZN Opinion 781 to Voigt (1834), in the German edition of Cuvier's work; and later to Gray (1833) in Griffith & Pidgeon's translation of the same work. [details]
To European Nucleotide Archive, ENA (Calmella) (from synonym Calmella Eliot, 1906)
To European Nucleotide Archive, ENA (Carronella) (from synonym Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To European Nucleotide Archive, ENA (Flabellina)
To European Nucleotide Archive, ENA (Paraflabellina) (from synonym Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To Genbank (from synonym Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To Genbank (from synonym Calmella Eliot, 1906)
To Genbank (from synonym Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To Sea Slug Forum (via archive.org)
To ITIS
To European Nucleotide Archive, ENA (Carronella) (from synonym Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To European Nucleotide Archive, ENA (Flabellina)
To European Nucleotide Archive, ENA (Paraflabellina) (from synonym Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To Genbank (from synonym Carronella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To Genbank (from synonym Calmella Eliot, 1906)
To Genbank (from synonym Paraflabellina Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, H. Saito, Lundin, Schrödl & Picton, 2017)
To Sea Slug Forum (via archive.org)
To ITIS