Obseruationes circa viuentia, quæ in rebus non viuentibus reperiuntur : Cum micrographia curiosa siue Rerum minutissimarum obseruationibus, quæ ope microscopij recognitæ ad viuum exprimuntur : his accesserunt aliquot animalium testaceorum icones non antea in lucem editæ : omnia curiosorum naturæ exploratorum vtilitati & iucunditati expressa & oblata - Buonanni, Filippo, 1638 -1725 (Typis Dominici Antonij Herculis, 1691)

Observationes et historiae omnes & singulae è Guijielmi Harvei libello De generatione animalium excerptae, & in accuratissimum ordinem redactae : item Wilhelmi Langly De generatione animalium observationes quaedam : accedunt Ovi faecundi singulis ab incubatione diebus factae inspectiones : ut et Observationum anatomico-med. decades quatuor, denique Cadavara balsamo condiendi modus - Harvey, William, 1578 -1657 (Typis Abrahami Wolfgang, 1674)

Observationes in historiam naturalem et anatomiam comparatam in itinere Groenlandico factae ... / auctor Martinus Guilelmus Mandt - Mandt, Martin Wilhelm, 1800 -1858 (Formis Brueschckianis, 1822)

Observationes zoologicas de zoophytis coralliis, speciatim de genere Fungia : et descriptionem nonnullarum hujus generis specierum novarum vel nondum accuratius cognitarum / edidit Frid. Sigism. Leuckart ; cum tabulis IV aere incisis - Leuckart, F. S. (Friedrich Sigismund), 1794 -1843 (1841)

Observationum medicarum Castrensium Hungaricarum decades tres. In usum publicum hoc tempore recusae - Meibom, Heinrich, 1638 -1700 (F. Lüderwaldi, 1685)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1963)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2009)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2010)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2012)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2013)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1973)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1974)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1992)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1993)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1958)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1971)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1992)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1999)

Oceanus - Woods Hole Oceanographic Institution. (Woods Hole Oceanographic Institution, 1983)

Oceanus - Woods Hole Oceanographic Institution. (Woods Hole Oceanographic Institution, 1990)

Oceanus - Woods Hole Oceanographic Institution. (Woods Hole Oceanographic Institution, 1991)

Oesterreichisches botanisches Wochenblatt ([L.W. Seidel], 1853)

Œuvres complètes de Buffon avec la nomenclature Linnéenne et la classification de Cuvier - Buffon, Georges Louis Leclerc, comte de, 1707 -1788 (1853)

Oeuvres complètes de Christiaan Huygens. Publiées par la Société hollandaise des sciences - Huygens, Christiaan, 1629 -1695 (M. Nijhoff, 1888)

Of microscopes and the discoveries made thereby : illustrated with many copper-plates - Baker, Henry, 1698 -1774 (Printed for J. Dodsley, 1785)

Official lists and indexes of names and works in zoology. Supplement 1986-2000 - International Commission on Zoological Nomenclature (International Trust for Zoological Nomenclature, c/o Natural History Museum, 2001)

Official lists and indexes of names and works in zoology - International Commission on Zoological Nomenclature (ICZN, 1987)

Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1838)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1857)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1864)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1878)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1884)

Ohio fossils - La Rocque, Aurèle, 1909 -1990 (Ohio Dept. of Natural Resources, Division of Geological Survey, 1955)

Les Oiseaux d'Europe décrits par C. J. Temminck - Werner, Johann Carl. (1848)

Okens Lehrbuch der Naturgeschichte - Oken, Lorenz, 1779 -1851 (Bei Carl Heinrich Reclam, 1815)

Om slägtet Sorex, med några nya arters beskrifning - Sundevall, Carl J., 1801 -1875 (Kungliga Vetenskapsakademien, 1842)

Om Sveriges hydrachnider - Neuman, Carl Julius, 1839 -1912 (Kongl. boktryckeriet, P.A. Norstedt & söner, 1880)

Om tillvaron af ett centrum i naturliga grupper såväl inom djur-som växt-verlden - Lindblad, Matts Adolf, 1821 -1899 (Berklingska Boktr, 1857)

Omnium stirpium sciagraphia et icones : quibus plantarum et radicum tum in hortis cultarum, tum in vrbium fossis & muris, pratis, aruis, montibus, collibus, nemoralibus, fluviis, riguis & littoralibus, villis & pagis, spontè provenientium, nomina, figura, natura, natales, synonyma, vsus & virtutes, docentur : cum doctissimorum scriptorum circa eas consensu & dissensu - Chabrey, Dominique, 1610 -1669 (Sumptibus Samuelis de Tournes, 1678)

On a new genus of the Crustacea, and the species on which it is established. Read July 8, 1817 - Say, Thomas, 1787 -1834 (Academy of Natural Sciences of Philadelphia, 1817)

On animal and vegetable parasites of the human body a manual of their natural history, diagnosis, and treatment - Lankester, Edwin, 1814 -1874 (Printed for the Sydenham Society, 1857)

On animal and vegetable parasites of the human body, a manual of their natural history, diagnosis, and treatment - Küchenmeister, Friedrich, 1821 -1890 (Printed for the Sydenham Society, 1857)

On animal and vegetable parasites of the human body, a manual of their natural history, diagnosis, and treatment - Küchenmeister, Friedrich, 1821 -1890 (Printed for the Sydenham society, 1857)

On growth and form - Thompson, D'Arcy Wentworth, 1860 -1948 (University press, 1917)

On growth and form - Thompson, D'Arcy Wentworth, 1860 -1948 (University Press, 1945)

On some remarkable forms of animal life from the great deeps off the Norwegian coast... - Sars, G. O. (Georg Ossian), 1837 -1927 (Printed by Brøgger & Christie [etc.], 1872)

On the anatomy of vertebrates - Owen, Richard, 1804 -1892 (Longmans, Green, 1866)

On the anatomy of vertebrates ... - Owen, Richard, 1804 -1892 (Longmans, Green and Co, 1866)

On the entomology and uses of silk : with a list of the families, genera, and species of silk producers known up to the present date - Wardle, Thomas, Sir, 1831 -1909 (G. T. Bagguley, Printer, 1880)

On the fauna and flora of the west of Scotland. Meeting at Glasgow, September, 1876 - British Association for the Advancement of Science. (Blackie, 1876)

On the relationships of the spider genus Cybaeodes (Araneae, Dionycha) - Platnick, Norman I. (American Museum of Natural History, 1992)

On the Silurian Gastropoda and Pteropoda of Gotland - Lindström, Gustaf, 1829 -1901 (P.A. Norstedt, 1884)

On the vegetation of the Carboniferous period, as compared with that of the present day - Hooker, Joseph Dalton, 1817 -1911

On two orders of Arachnida : Opiliones, especially the suborder Cyphophthalmi, and Ricinulei, namely the family Cryptostemmatoidae - Royal Society (Great Britain) (University Press, 1904)

Onomasticon zoicon, plerorumque animalium differentias & nomina propria pluribus linguis exponens : cui accedunt Mantissa anatomica, et quaedam De variis fossilium generibus - Charleton, Walter, 1619 -1707 (Apud Jacobum Allestry ..., 1668)

Onomatologia Anatomica. Geschichte und Kritik der anatomischen Sprache der Gegenwart, mit besonderer Berücksichtigung ihrer Barbarismen, Widersinnigkeiten, Tropen und grammatikalischen Fehler - Hyrtl, Joseph, 1811 -1894 (W. Braumüller, 1880)