Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1975)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1978)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1979)

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 Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1977)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1981)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1982)

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, 1994)

Occasional papers of the Natural History Museum, the University of Kansas, Lawrence, Kansas - University of Kansas. Museum of Natural History. (The University, 1994)

Occasional papers of the Natural History Museum, the University of Kansas, Lawrence, Kansas - University of Kansas. Museum of Natural History. (The University, 1995)

Occasional papers of the Natural History Museum, the University of Kansas, Lawrence, Kansas - University of Kansas. Museum of Natural History. (The University, 1996)

Occasional papers - Tulane University. Museum of Natural History. (The Museum, 1994)

Oceanus - Woods Hole Oceanographic Institution. (Woods Hole Oceanographic Institution, 1979)

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)

Old bones : or, Notes for young naturalists - Brooks, Vincent, 1815? -1885 (Robert Hardwicke, 1861)

On British wild flowers considered in relation to insects - Lubbock, John, Sir, 1834 -1913 (Macmillan, 1909)

On certain problems of vertebrate embryology - Royal College of Physicians of Edinburgh. (G. Fischer, 1896)

On Müller's and Cuvier's concepts of pharyngognath and labyrinth fishes and the classification of percomorph fishes : with an atlas of percomorph dorsal gill arches - Patterson, Colin (American Museum of Natural History, 1990)

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 biology of our flat-fishes and on the decrease of our flat-fish fisheries, with some observations showing how to remedy the latter and promote the flat-fish fisheries in our seas east of the Skaw - Petersen, C. G. Joh. (Carl Georg Johannes), 1860 -1928 (Centraltrykkeriet, 1894)

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 frequent occurrence of vegetable parasites in the hard structures of animals - Kölliker, Albert, 1817 -1905 ([s.n.], 1859)

On the morphology of the duck and the auk tribes - Parker, William Kitchen William Kitchen Parker 1823 -1890 (s.n.], 1890)

On the relationships of phallostethid fishes (Atherinomorpha) : with notes on the anatomy of Phallostethus dunckeri Regan, 1913 - Parenti, Lynne R (American Museum of Natural History, 1984)

On the structure and development of the skull in the Batrachia - Royal Society (Great Britain) (Royal Society, 1881)

On the structure and development of the skull in the mammalia - Parker, William Kitchen William Kitchen Parker 1823 -1890 (Royal Society of London, 1874)

On the structure and development of the skull of the common frog (Rana temporaria, L.) - Parker, William Kitchen William Kitchen Parker 1823 -1890 (Royal Society, 1871)

On the structure and development of the vertebral column of Amia - Hay, Oliver Perry, 1846 -1930 (1895)

On the structures and distribution of the genera of the arciferous Anura - Cope, E. D. (Edward Drinker), 1840 -1897 (s.n, 1866)

Ontogeny and systematics of fishes : based on an international symposium dedicated to the memory of Elbert Halvor Ahlstrom - United States. National Marine Fisheries Service. (American Society of Ichthyologists and Herpetologists, 1984)

Ontogeny of the ethmoidal region and hyopalatine arch in Macrognathus pancalus (Percomorpha, Mastacembeloidei) : with critical remarks on mastacembeloid inter- and intrarelationships - Britz, Ralf, 1964 - (American Museum of Natural History, 1996)

De ontwikkeling van het chondrocranium van Alytes obstetricans voor de metamorphose - Seters, Wouter Hendrik van. ("Het Klaverblad", 1921)

Opuscula zoologica - Zoologische Staatssammlung München. (Zoologische Staatssammlung, 1964)

The origin of the fittest : essays on evolution - Cope, E. D. (Edward Drinker), 1840 -1897 (D. Appleton, 1887)

The origin of the fittest : essays on evolution - Cope, E. D. (Edward Drinker), 1840 -1897 (Macmillan and Company, 1887)

The origin of the fittest; essays on evolution - Cope, E. D. (Edward Drinker), 1840 -1897 (D. Appleton, 1887)

Origin of the Weberian apparatus and the relationships of the ostariophysan and gonorynchiform fishes - Anderson, Sydney, 1927 -2018 (American Museum of Natural History, 1970)

The origin of vertebrates - Gaskell, Walter Holbrook, 1847 -1914 (Longmans, Green, 1908)

The origin of vertebrates - Gaskell, Walter Holbrook, 1847 -1914 (Longmans, Green, and co, 1908)

Osteology, phylogeny, and higher classification of the fishes of the order Plectognathi (Tetraodontiformes) - United States. National Marine Fisheries Service. (U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, 1980)

Otolith atlas of southern African marine fishes - Hecht, T. (Thomas) (J.L.B. Smith Institute of Ichthyology, 1995)

Outline for an educational exhibit of fishes - Lucas, Frederic A. (Frederic Augustus), 1852 -1929 (Govt. print. off, 1910)

An outline of the theory of organic evolution, with a description of some of the phenomena which it explains - Metcalf, Maynard M. (Maynard Mayo), 1868 -1940 (The Macmillian company; [etc., etc.], 1904)

An outline of the theory of organic evolution with a description of some of the phenomena which it explains - Metcalf, Maynard M. (Maynard Mayo), 1868 -1940 (MacMillan, 1906)

An outline of the theory of organic evolution, with a description of some of the phenomena which it explains - Metcalf, Maynard M. (Maynard Mayo), 1868 -1940 (The Macmillian company; [etc., etc.], 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 anatomy of vertebrates - Kingsley, J. S. (John Sterling), 1854 -1929 (P. Blakiston, 1917)

Outlines of evolutionary biology - Dendy, Arthur, 1865 -1925 (Constable, 1912)

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

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

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

Outlines of vertebrate palæontology for students of zoology - Woodward, Arthur Smith, 1864 -1944 (University Press, 1898)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Young J. Pentland, 1892)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (D. Appleton & Co, 1892)