A synopsis of the classification of the fresh-water Mollusca of North America, north of Mexico, and a catalogue of the more recently described species - Walker, Bryant, 1856 -1936 (The University, 1918)

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 (Woodfall, 1842)

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 Woodfall, 1837)

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, 1835)

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, 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 and Son, Angel Court, Skinner Street, 1840)

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

Synopsis of the flora of the Laramie group - Ward, Lester F. (Lester Frank), 1841 -1913 (Govt. print. off, 1885)

Synopsis plantarum; seu, Enumeratio systematica plantarum plerumque adhuc cognitarum cum differentiis specificis et synonymis selectis ad modum Persoonii elaborata - Dietrich, David Nathanael Friedrich, 1800 -1888 (B. F. Voigtii, 1839)

Synopsis plantarum :seu, Enumeratio systematica plantarum plerumque adhuc cognitarum cum differentiis specificis et synonymis selectis ad modum Persoonii elaborata - Dietrich, David Nathanael Friedrich, 1800 -1888 (B. F. Voigtii, 1840)

Synoptical flora of North America - Gray, Asa, 1810 -1888 (American Book Company, 1895)

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

A system of geology with a theory of the earth : and an explanation of its connexion with the sacred records - Macculloch, John, 1773 -1835 (Longman, Rees, Orme, Brown, and Green, 1831)

Systema helminthum / auctore Carolo Mauritio Diesing ... Sumptibus Academiae caesareae scientiarum - Diesing, Karl Moritz, 1800 -1867 (W. Braumüller, 1851)

Systema mycologicum : sistens fungorum ordines, genera et species, huc usque cognitas, quas ad normam methodi naturalis determinavit - Fries, Elias, 1794 -1878 (Ex Officina Berlingiana, 1821)

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

Systematics and zoogeography of the land and fresh-water mollusca of the New Hebrides - Solem, Alan, 1931 - (Chicago Natural History Museum, 1959)

Systematische Eintheilung der Land- und Fluss-Weichthiere nach ihren wesentlichen Kennzeichen, vorzuglich von der Schale : (Aus Histoire naturelle des Mollusques terrestres et fluiratiles de la France. Par Jacq. Philipp Raym. Deraparnaud.) - Sturm, Jakob, 1771 -1848 ([Gedruckt auf Kosten des Herausgebers], 1815)

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

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

Systematisches Verzeichniss der bis jetzt bekannt gewordenen Schweizer-Conchylien - Studer, Théophil, 1845 -1922 (Gedruckt in der Stämpflischen Buchdruckerey, 1820)