Symbolae ad historiam heliceorum - Pfeiffer, Louis (Ludwig Georg Karl), 1805 -1877 (Sumptibus & typis Th. Fischeri, 1841)

A synonymic catalogue of Lepidoptera Heterocera. (Moths) : Vol. 1. Sphinges and bombyces - Kirby, W. F. (William Forsell), 1844 -1912 (Gurney & Jackson, 1892)

A synonymic catalogue of Orthoptera - British Museum (Natural History). Department of Zoology. (Printed by order of the Trustees [by Taylor and Francis], 1906)

Synonymy of the British non-Marine Mollusca (Recent and Post-Tertiary) - Woodward, Bernard Barham, 1853 -1930 (1926)

Synopsis methodica molluscorum generum omnium et specierum earum, quae in Museo Menkeano adservantur : cum synonymia critica et novarum specierum diagnosibus - Menke, Karl Theodor, 1791 -1861 (Sumtibus auctoris, typis Henrici Gelpke, 1828)

Synopsis methodica molluscorum generum omnium et specierum earum, quae in Museo Mankeano adservantur : cum synonymia critica et novarum specierum diagnosibus / auctore Carolo Theodoro Menke - Menke, Karl Theodor, 1791 -1861 (Sumtibus auctoris, typis Henrici Gelpke, 1828)

Synopsis methodica molluscorum generum omnium et specierum earum, quae in Museo Menkeano adservantur : cum synonymia critica et novarum specierum diagnosibus - Menke, Karl Theodor, 1791 -1861 (G. Uslar, 1830)

Synopsis methodica molluscorum generum omnium et specierum earum, quae in Museo Menkeano adservantur : cum synonymia critica et novarum specierum diagnosibus - Menke, Karl Theodor, 1791 -1861 (sumtibus Georgi Uslar, 1830)

Synopsis molluscorum extramarinorum Scandinaviæ (Sueciæ, Norvegiæ, Daniæ & Fenniæ) - Westerlund, Carl Agardh, 1831 -1908 ([s.n.], 1897)

Synopsis novorum, generum, specierum et varietatum, testaceorum viventium anno 1834 promulgatorum, adjectis iis quae in diariis societatis zoologicae Londinensis ab anno 1830 editis relata sunt. Supplementi loco ad. ill. Wiegmann historiae naturalis promtuarium - Müller, Th. (F. Nicolai, 1836)

Synopsis of an arrangement of invertebrate animals in the Free Public Museum of Liverpool - Higgins, H. H. (1874)

Synopsis of an arrangement of invertebrate animals in the Free Public Museum of Liverpool - Higgins, H. H. (Printed by D. Marples & Co, 1880)

Synopsis of the contents of the British Museum - British Museum (Woodfall, 1842)

Synopsis of the contents of the British Museum - British Museum (Printed by G. Woodfall and Son, 1824)

Synopsis of the contents of the British Museum - British Museum ([the Museum], 1823)

Synopsis of the contents of the British Museum - British Museum ([The Museum], 1827)

Synopsis of the contents of the British Museum - British Museum (printed by Woodfall, 1837)

Synopsis of the contents of the British Museum - British Museum (Printed by G. Woodfall, 1838)

Synopsis of the contents of the British Museum - British Museum (printed by G. Woodfall, 1839)

Synopsis of the contents of the British Museum - British Museum (printed by G. Woodfall, 1838)

Synopsis of the contents of the British Museum - British Museum (Printed by G. Woodfall, Angel Court, Skinner Street, 1840)

Synopsis of the contents of the British Museum - British Museum (printed by G. Woodfall, 1837)

Synopsis of the contents of the British Museum - British Museum (Printed by G. Woodfall, Angel Court, Skinner Street, 1836)

Synopsis of the contents of the British Museum - British Museum (Printed by G. Woodfall and Son, 1826)

Synopsis of the contents of the British Museum - British Museum (Woodfall, 1841)

Synopsis of the contents of the British Museum - British Museum (Printed by G. Woodfall and Son, Angel Court, Skinner Street, 1840)

System der urweltlichen Konchylien : durch Diagnose, Analyse und Abbildung der Geschlechter erläutert - Bronn, H. G. (Heinrich Georg), 1800 -1862 (J.C.B. Mohr, 1824)

The system of the order Geophila (Helicida) (Gastropoda, Pulmonata) - Boss, Kenneth J. (Kenneth Jay), 1935 -2014 (Dept. of Mollusks, Harvard University, 1985)

Systema naturae, per regna tria naturae : secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Typis Ioannis Thomae, 1767)

Systema naturae per regna tria naturae : secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Typis Ioannis Thomae, 1767)

Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Typis Ioannis Thomae von Trattner, 1767)

Systema natvræ per regna tria natvræ : secvndum classes, ordines, genera, species, cvm characteribus, differentiis, synonymis, locis - Gmelin, Johann Friedrich, 1748 -1804 (Typis Academicis, 1793)

Systema natvrae per regni tria natvrae secvndvm classes, ordines, genera, species, cvm characteribvs, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Io. Iac. Cvrt, 1760)

Systematic arrangement of the figures - Gray, John Edward 1800 -1875 (Longman, Brown, Green and Longmans?, 1850?, 1850)

Systematic list of the Frederick E. Edwards collection of British oligocene and eocene Mollusca in the British Museum (Natural History), with references to the type-specimens from similar horizons contained in other collections belonging to the Geological Department of the Museum - British Museum (Natural History). Department of Geology. (Printed by order of the Trustees, 1891)

Systematische Abhandlung über die Erd- und Flussconchilien welche um Augsburg und der um liegenden Gegend gefunden werden : als ein Beytrag zur vaterländischen Naturgeschichte - Alten, Johann Wilhelm von, 1770 -1854 (Gedruckt auf Kosten des Verfassers, auch bey demselben und in Commission bey Joh. Jak. Palm in Erlangen, zu haben, 1812)

Systematische Bearbeitung der Schmetterlinge von Europa, zugleich als Text, Revision und Supplement zu Jakob Hübner's Sammlung europäischer Schmetterlinge - Hübner, Jacob, 1761 -1826 (In Commission bei G. J. Manz, 1843)

Systematisches Conchylien-Cabinet - Kobelt, Wilhelm, 1840 -1916 (Bauer und Raspe, 1837)

Systematisches Conchylien-Cabinet - Kobelt, Wilhelm, 1840 -1916 (Bauer und Raspe, 1862)