Öfversigt af Finska vetenskaps-societetens förhandlingar - Suomen Tiedeseura (s.n.], 1889)

Öfversigt af Kongl. Vetenskaps-akademiens forhandlingar - Kungl. Svenska vetenskapsakademien. (P. A. Norstedt & Söner, 1862)

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, 1876)

Okens Lehrbuch der Naturgeschichte - Oken, Lorenz, 1779 -1851 (Bei Carl Heinrich Reclam, 1816)

Omphalos: an attempt to untie the geological knot ... - Gosse, Philip Henry, 1810 -1888 (J. Van Voorst, 1857)

On a collection of Sierra Leone lepidoptera - Schaus, William, 1859 -1942 (R.H. Porter, 1893)

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 archetype and homologies of the vertebrate skeleton - Owen, Richard, 1804 -1892 (John Van Voorst, 1848)

On the crustacea and echinodermata of the Pacific shores of North America - Stimpson, William, 1832 -1872 (Boston Society of Natural History, 1857)

On the nature of limbs - Owen, Richard, 1804 -1892 (John Van Voorst, 1849)

On the phylogeny of hair - Elias, Hans, 1907 -1985 (American Museum of Natural History, 1957)

On the reptiles and batrachians - Garman, Samuel, 1843 -1927 (Printed for the Museum?, 1883)

On the reptiles and Batrachians of North America - Garman, Samuel, 1843 -1927 (Major, Johnston & Barrett, Yeoman, 1883)

On the so-called Dimorphism in the Genus Cambarus - Faxon, Walter, 1848 -1920 (J.D. & E.S. Dana, 1884)

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

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

The ontogeny and phylogeny of the sternum - Hanson, Frank Blair, ([publisher not identified], 1919)

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

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1904)

Opuscoli scientifici d'entomologia, di fisica e d'agricoltura - Termeyer, Ramón María, 1737 -1814 (Nella Stamperia del Giornale italico di Carlo Dova, contrada S. Rafaello, num. 998, 1807)

The orchid-grower's manual, containing descriptions of the best species and varieties of orchidaceous plants in cultivation ... - Williams, Benjamin Samuel, 1822 -1890 (Victoria and Paradise nurseries, 1894)

Orchideeën welke in Ned.-Indië gekweekt kunnen worden - Dakkus, P. M. W. (A. C. Nix, 1935)

Die ordnungen, familien und gattungen der reptilien als prodrom einer naturgeschichte derselben - Oppel, Michael, 1782 -1820 (In commission bey J. Lindauer, 1811)

Oriental commerce; or, The East India Trader's complete guide; containing a geographical and nautical description of the maritime parts of India, China, Japan, and neighbouring countries, including the eastern islands, and the trading stations on the passage from - Milburn, William. (Printed for Kingsbury, Parbury, and Allen, 1825)

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)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1905)

Ornitologia italiana : opera postuma - Savi, Paul, 1798 -1871 (Successori Le Monnier, 1873)

Osteologia avium, or, A sketch of the osteology of birds - Brooks, Vincent, 1815? -1885 (Published by R. Hobson, Wellington, Salop, 1867)

Ostrea; or, The loves of the oysters. A lay - Gerard, James W. (James Watson), 1823 -1900 (T. J. Crowen, 1857)

Otia conchologica : descriptions of shells and mollusks from 1839 to 1862 / by Augustus A. Gould, M.D - Gould, Augustus A. (Augustus Addison), 1805 -1866 (1846)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1897)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1915)

The outline of science : a plain story simply told - Thomson, J. Arthur (John Arthur), 1861 -1933 (G. P. Putnam's sons, 1922)

Outlines of comparative anatomy of vertebrates - Kingsley, J. S. (John Sterling), 1854 -1929 (P. Blakiston, 1917)

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

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)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Young J. Pentland, 1895)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Pentland, 1899)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (D. Appleton & Co, 1895)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (H. Frowde and Hodder & Stoughton, 1899)

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

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (D. Appleton, 1895)

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (D. Appleton, 1906)

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)

Oeuvres du Comte de Lacépède, comprenant l'histoire naturelle des quadrupèdes ovipares, des serpens, des poissons et des cétacés - La Cépède, M. le comte de (Bernard Germain Etienne de La Ville sur Illon), 1756 -1825 (Duménil, 1836)

Over de ontwikkeling van het chondrocranium en de kraakbeenige wervelkolom van eenige Urodela en Anura - Peeters, Johannes Leonardis Elbertus. (G.F. Theonville, 1910)

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, 1846)

Pacific seabirds : a publication of the Pacific Seabird Group - Pacific Seabird Group. (The Group, 2012)

Palaeontographica (Theodor Fischer, 1859)

Palaeontographica (Theodor Fischer, 1871)

Palaeontographica (Theodor Fischer, 1902)

Palaeontology - Palaeontological Association (Palaeontological Association, 1998)