Sveriges och Norges ryggradsdjur I. Däggdjuren - Lilljeborg, Wilhelm, 1816 -1908 (1871)

Sylloge fungorum omnium hucusque cognitorum - Saccardo, P. A. (Pier Andrea), 1845 -1920 (sumptibus auctoris, 1889)

Syllogeus - National Museum of Natural Sciences (Canada) (National Museum of Natural Sciences, 1978)

Symbolae physicae, seu, Icones et descriptiones corporum naturalium novorum aut minus cognitorum : quae ex itineribus per Libyam Aegyptum Nubiam Dongalam Syriam Arabiam et Habessiniam publico institutis sumptu Friderici Guilelmi Hemprich et Christiani Godofredi Ehrenberg : studio annis MDCCCXX-MDCCCXXV redierunt - Schumann, K. (Karl) 1851 -1904 (Ex Officina Academica, venditur a Mittlero, 1830)

Synopsis filicum; or, A synopsis of all known ferns, including the Osmundaceae, Schizaeaceae, Marattiaceae, and Ophioglossaceae (chiefly derived from the Kew herbarium) Accompanied by figures representing the essential characters of each genus - Baker, John Gilbert, 1834 -1920 (R. Hardwicke, 1874)

Synopsis methodica animalium quadrupedum et serpentini generis : vulgarium notas characteristicas, rariorum descriptiones integras exhibens : cum historiis & observationibus anatomicis perquam curiosis : praemittuntur nonnulla De animalium in genere, sensu, generatione, divisione, &c - Ray, John, 1627 -1705 (Impensis S. Smith & B. Walford, 1693)

Synopsis mycologiae Venetae secundum matrices - Cuboni, Giuseppe, 1852 -1920 (Typis Seminarii, 1886)

Synopsis of quadrupeds - Pennant, Thomas, 1726 -1798 (Printed by J. Monk, 1771)

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

Synopsis of the Digenea of mammals of North America - Alberta. Animal Health Division. (Alberta Agriculture, Animal Health Division, 1988)

A synopsis of the mammals of North America and the adjacent seas - Elliot, Daniel Giraud, 1835 -1915 ([Field Columbia Museum], 1901)

Synopsis of the parasites of vertebrates of Canada : ectoparasites of terrestrial mammals - Alberta. Animal Health Division. (Alberta Agriculture, Animal Health Division, 1986)

A synoptic text-book of zoölogy, for colleges and schools - Weysse, Arthur Wisswald, 1867 - (Macmillan, 1904)

A synoptical table of British organic remains : in which, all the edited British fossils are systematically and stratagraphically arranged, in accordance with the views of the geologists of the present day; and a reference given to their localities, strata, and engraved figures : accompanied by a lithograph of the fossil turtle in the Norfolk and Norwich Museum - Woodward, Samuel, 1790 -1838 (Longman, Rees, Orme, Brown, and Green; and John Stacy, Norwich, 1830)

A synthesis of evolutionary theory - Ross, Herbert H. (Herbert Holdsworth), 1908 -1978 (Prentice-Hall, 1962)

System of ophthalmology - Duke-Elder, Stewart, Sir, 1898 -1978 (Mosby, 1958)

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

Systema naturæ in quo naturae regna tria, secundum classes, ordines, genera, species, systematice, proponuntur - Linné, Carl von, 1707 -1778 (Apud G. Kiesewetter, 1740)

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)

A systematic catalogue of British insects : being an attempt to arrange all the hitherto discovered indigenous insects in accordance with their natural affinities - Stephens, James Francis, 1792 -1853 (Baldwin and Cradock, 1829)

Systematic results of the study of North American land mammals during the years 1901 and 1902 - Miller, Gerrit S. Jr. (Gerrit Smith), 1869 -1956 (Society of Natural History, 1903)

Systematic results of the study of North American land mammals to the close of the year 1900 - Miller, Gerrit S. Jr. (Gerrit Smith), 1869 -1956 (Society of Natural History, 1901)