Nyt magazin for naturvidenskaberne - Physiographiske forening i Christiania. (Johan Dahl, 1922)

Occasional papers - Boston Society of Natural History. (1904)

The ocean world: being a description of the sea and its living inhabitants - Figuier, Louis, 1819 -1894 (Cassell, Petter and Galpin, 1869)

The ocean world: being a description of the sea and some of its inhabitants - Figuier, Louis, 1819 -1894 (Cassell, 1872)

The ocean world : being a descriptive history of the sea and its living inhabitants - Figuier, Louis, 1819 -1894 (Chapman and Hall, 1868)

The ocean world: being a descriptive history of the sea and its living inhabitants - Figuier, Louis, 1819 -1894 (Chapman & Hall, 1868)

The ocean world: being a descriptive history of the sea and its living inhabitants - Figuier, Louis, 1819 -1894 (D. Appleton & co, 1868)

The oceanic Hydrozoa : a description of the Calycophoridæ and Physophoridæ observed during the voyage of H.M.S. "Rattlesnake," in the years 1846-1850 - Huxley, Thomas Henry, 1825 -1895 (Printed for the Ray society, 1859)

Oceanology : biology of the ocean. Volume 2, Biological productivity of the ocean - United States. National Oceanic; Atmospheric Administration. (National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Center, 1985)

Oceanus - Woods Hole Oceanographic Institution. (Woods Hole Oceanographic Institution, 1964)

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

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)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1846)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1848)

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, 1866)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1867)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1869)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1872)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1881)

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

Om de senglaciale og postglaciale nivåforandringer i Kristianiafeltet (Molluskfaunan) - Brøgger, Waldemar Christopher, 1851 -1940 (I kommission hos H. Aschehoug & co, 1900)

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 molecular and microscopic science - Somerville, Mary Fairfax, 1780 -1872 (J. Murray, 1869)

On molecular and microscopic science - Somerville, Mary, 1780 -1872 (J. Murray, 1869)

On parthenogenesis - Owen, Richard, 1804 -1892 (John Van Voorst, 1849)

On parthenogenesis, or The successive production of procreating indivduals from a single ovum. A discourse introductory to the Hunterian lectures on generation and development, for the year 1849, delivered at the Royal college of surgeons of England - Owen, Richard, 1804 -1892 (J. Van Voorst, 1849)

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.], 1875)

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 embryology of echinoderms - Agassiz, Alexander, 1835 -1910 (s.n.], 1864)

On the food of the halibut, with notes on the food of scorpaena, phycis blennoides, the garpike and chimaera monstrosa - Scott, Thomas, 1840 -1929 (Fishery Board, 1911)

Ophiura brevispina - Brooks, William Keith, 1848 -1908 (Govt. print. off, 1899)

Ophiura brevispina - Brooks, William Keith, 1848 -1908 (The Johns Hopkins Press, 1900)

Ophiura brevispina - National Academy of Sciences (U.S.) (National Academy of Sciences, 1899)

Ophiurans of the Philippine seas and adjacent waters - Clark, Austin Hobart, 1880 -1954 (Govt. print. off, 1922)

Ophiuridæ and Astrophytidæ / by Theodore Lyman - Lyman, Theodore, 1833 -1897 ([University Press: Welch, Bigelow, & co.], 1865)

The Ophiuridae / by C. F. Lütken and Th. Mortensen - Lütken, Chr. Fr. (Christian Frederik), 1827 -1901 (Printed for the Museum, 1899)

Our common British fossils, and where to find them; a handbook for students - Taylor, J. E. (John Ellor), 1837 -1895 (Chatto, 1885)

Our living world; an artistic edition of the Rev. J. G. Wood's Natural history of animate creation - Wood, J. G. (John George), 1827 -1889 (S. Hess, 1885)

An outline of the natural history of our shores - Sinel, Joseph. (S. Sonnenschein, 1906)

An outline of the natural history of our shores - Sinel, Joseph. (Swan Sonnenschein & Co, 1906)

Outlines of comparative anatomy and medical zoology - Allen, Harrison, 1841 -1897 (Lippincott, 1874)

Outlines of comparative anatomy and medical zoology - Allen, Harrison, 1841 -1897 (J.B. Lippincott & co, 1869)

Outlines of comparative physiology : touching the structure and development of the races of animals, living and extinct, for the use of schools and colleges - Agassiz, Louis, 1807 -1873 (Bell & Daldy, 1867)

Outlines of comparative physiology : touching the structure and development of the races of animals, living and extinct - Agassiz, Louis, 1807 -1873 (H. G. Bohn, 1851)

Outlines of comparative physiology : touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges - Agassiz, Louis, 1807 -1873 (H.G. Bohn, 1851)

Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges - Agassiz, Louis, 1807 -1873 (Bell & Daldy, 1870)

Outlines of evolutionary biology - Dendy, Arthur, 1865 -1925 (D. Appleton and company, 1914)

Outlines of evolutionary biology - Dendy, Arthur, 1865 -1925 (D. Appleton and company, 1912)

Outlines of general zoology - Baird, Spencer Fullerton, 1823 -1887 (Rudolph Garrigue, 1851)

Outlines of oryctology. An introduction to the study of fossil organic remains; especially those found in the British strata: intended to aid the student in his inquiries respecting the nature of fossils, and their connection with the formation of the earth ... - Parkinson, James, 1755 -1824 (M.A. Nattali; [etc., etc, 1831)

Outlines of oryctology : An introduction to the study of fossil organic remains; especially those found in the British strata ... / by James Parkinson - Parkinson, James, 1755 -1824 (1831)

Outlines of the natural history of Great Britain and Ireland, containing a systematic arrangement and concise description of all the animals, vegetables and fossiles which have hitherto been discovered in these kingdoms - Berkenhout, John, 1730 -1791 (Printed for P. Elmsly (Successor to Mr. Vaillant), 1769)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Appleton, 1916)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (H. Frowde and Hodder & Stoughton, 1921)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Humphrey Milford, Oxford University Press, 1929)

Oversigt af Norges echinodermer - Sars, M. (Michael), 1805 -1869 (Trykt i Brøgger & Christie's bogtrykkerie, i commission hos J. Dybwad, 1861)

Oversigt over det Kongelige Danske videnskabernes selskabs forhandlinger = Bulletin de l'Académie royale des sciences et des lettres de Danemark - Kongelige Danske videnskabernes selskab. (A.F. Høst, 1872)

Oversigt over Gronlands Echinodermata samt over denne Dyreklasses geographiske og bathymetriske udbredningsforhold i de nordiske Have - Lütken, Chr. Fr. (Christian Frederik), 1827 -1901 (1857)