Observations on the genus Unio, together with descriptions of new genera and species ... - Lea, Isaac, 1792 -1886 (Printed by J. Kay, Jun., & Co. [etc.], 1857)

Occasional papers - San Diego Society of Natural History. (San Diego Society of Natural History, 1954)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1915)

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, 2010)

Occasional papers of the Museum of Zoology, University of Michigan - University of Michigan. Museum of Zoology. (University of Michigan, 1913)

Occasional papers of the Museum of Zoology, University of Michigan - University of Michigan. Museum of Zoology. (University of Michigan, 1921)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1946)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1954)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1972)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1975)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1977)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1984)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1997)

Occasional papers on mollusks - Harvard University. Museum of Comparative Zoology. Department of Mollusks. (Dept. of Mollusks, 1998)

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

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 description of the sea and some of its inhabitants - Figuier, Louis, 1819 -1894 (D. Appleton and Co, 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 ocean world : being a description of the sea and some of its inhabitants - Figuier, Louis, 1819 -1894 (D. Appleton, 1872)

Oeuvres scientifiques de M.J.-R. Bourgignat : précédées d'une préface biographique - Servain, Georges. (Impr. D. Dumoulin, 1891)

Oeuvres scientifiques; précédées d'une préf. biographique par Georges Servain - Servain, Georges. (D. Dumoulin, 1891)

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, 1844)

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, 1850)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1861)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1865)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1868)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1871)

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, 1873)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1875)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1880)

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

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1895)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1897)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1898)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1900)

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

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1909)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1900)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1910)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1911)

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

Om Limfjordens tidligere og nuværende marine fauna, med særligt hensyn til bløddyraunaen - Denmark. Ministeriet for kirke- og undervisningsvæsenet. (Gyldendal, 1884)

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

On the development and life-histories of the Teleostean food and other fishes - M'Intosh, William Carmichael, 1838 -1931 (R. Grant & Son, 1890)

On the land and fresh-water molluska of Lower Canada - Whiteaves, Joseph Frederick, 1835 -1909 (s.n, 1863)

On the North American species of the genus Atax (Fabr.) Bruz - Wolcott, Robert Henry, 1868 -1934 (University of Nebraska, 1899)

On the origin of freshwater faunas: a study in evolution - Sollas, W. J. (William Johnson), 1849 -1936 (Royal Dublin Society, 1884)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1958)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1956)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1957)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1955)

Opinions and declarations rendered by the International Commission on Zoological Nomenclature - International Commission on Zoological Nomenclature (Printed by order of the International Trust for Zoological Nomenclature, 1959)

Opuscula zoologica - Zoologische Staatssammlung München. (Zoologische Staatssammlung, 1958)

Opuscules de botanique - Clos, Dominique, 1821 -1908 (1859)