Odontography; or, A treatise on the comparative anatomy of the teeth; their physiological relations, mode of development, and microscopic structure, in the vertebrate animals - Owen, Richard, 1804 -1892 (H. Baillière, 1840)

Oeuvres complètes. Publiées sous la direction de J.-A. Barral - Arago, F. (François), 1786 -1853 (Gide et J. Baudry, 1854)

Oeuvres du comte de Lacépède : comprenant l'histoire naturelle des quadrupèdes ovipares, des serpents, des poissons et des cétacés; accompanées du portrait de l'auteur et d'environ 400 figures, exécutés pour cette édition par les meilleurs artistes - Cuvier, Georges, baron, 1769 -1832 (Chez F.D. Pillot, 1832)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1905)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1903)

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

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

Old bones : or, Notes for young naturalists, on vertbebrate animals, their fossil predecessors and allies - Symonds, W. S. 1818 -1887 (Robert Hardwicke, 1864)

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 contents of a bone cave in the island of Anguilla (West Indies) - Cope, E. D. (Edward Drinker), 1840 -1897 (Smithsonian institution, 1883)

On the development of the skeleton of the tuatara, Sphenodon punctatis ; with remarks on the egg, on the hatching, and on the hatched young - Howes, George Bond, 1853 -1905 (Printed for the Society, sold at their house in Hanover Square, 1901)

On the geology and natural history of the upper Missouri :Being the substance of a report made to Lieut. G.K. Warren, T.E. U.S.A - Hayden, F. V. (Ferdinand Vandeveer), 1829 -1887 (Printed by C. Sherman & son, 1862)

On the habits and instincts of animals - Swainson, William, 1789 -1855 (Printed for Longman, Orme, Brown, Green, & Longmans, 1840)

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

On the power, wisdom, and goodness of God : as manifested in the creation of animals, and in their history, habits, and instincts - Jones, Thomas Rymer, 1810 -1880 (H.G. Bohn, 1853)

On the power, wisdom and goodness of God, as manifested in the creation of animals, and in their history, habits and instincts - Kirby, William, 1759 -1850 (Carey, Lea & Blanchard, 1836)

On the power, wisdom and goodness of God as manifested in the creation of animals and in their history, habits and instincts - Kirby, William, 1759 -1850 (W. Pickering, 1835)

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

On the sclerotic ring of the eyes of birds and reptiles - Allis, Thomas 1788 -1875 (H. Sotheran, 1855)

Die Ontogenie der Primatenzähne : versuch einer Lösung der Gebissprobleme - Bolk, L. (Louis), 1866 -1930 (Verlag von Gustav Fischer, 1913)

Die Ontogenie der Primatenzähne - Bolk, L. (Louis), 1866 -1930 (G. Fischer, 1913)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1917)

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

The Oregon naturalist (Naturalist Pub. Co, 1896)

Organization of repetitive DNA in the primitive reptile (Sphenodon Punctatus) - Van Den Bussche, Ronald A. (Museum of Texas Tech University, 1998)

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)

Ornamental gardening in Florida, radio series - 1933-34 - Cooperative extension work in agriculture; home economics. (Cooperative extension work in agriculture and home economics, 1933)

Ornithological gazetteer of Colombia - Paynter, Raymond A. Jr. (Bird Dept., Museum of Comparative Zoology, Harvard University, 1997)

Ornithological gazetteer of Venezuela - Paynter, Raymond A. Jr. (Bird Dept., Museum of Comparative Zoology, Harvard University, 1982)

[Orr's Circle of the sciences. A series of treatises on the principles of science, with their application to practical pursuits. Organic nature ... - Owen, Richard, 1804 -1892 (W.S. Orr, 1854)

The osteology of the reptiles - Gregory, William K. (William King), 1876 -1970 (Harvard University Press, 1925)

Our country's animals and how to know them. A guide to the mammals, reptiles and amphibians of Great Britain - Gordon, W. J. (Simpkin, Marshall, Hamilton, Kent, 1904)

Our living resources : a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems - United States. National Biological Service. (U.S. Dept. of the Interior, National Biological Service, 1995)

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)

Our reptiles and batrachians : a plain and easy account of the lizards, snakes, newts, toads, frogs and tortoises indigenous to Great Britain - Cooke, M. C. (Mordecai Cubitt), 1825 -1914 (W. H. Allen & co., limited, 1893)

Our reptiles and batrachians; a plain and easy account of the lizards, snakes, newts, toads, frogs and tortoises indigenous to Great Britain - Cooke, M. C. (Mordecai Cubitt), 1825 -1914 (W. H. Allen & co., limited, 1893)

Our reptiles. A plain and easy account of the lizards, snakes, newts, toads, frogs, and tortoises indigenous to Great Britain - Cooke, M. C. (Mordecai Cubitt), 1825 -1914 (R. Hardwicke, 1865)

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 : intended principally for the use of students - Fyfe, Andrew, 1754 -1824 (Printed by J. Pillans & sons for Adam Black, South Bridge Street, 1813)

Outlines of comparative anatomy intended principally for the use of students - Fyfe, Andrew, 1754 -1824 (Printed by J. Pillans & Sons for Adam Black ... [etc.], 1818)

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

Outlines of economic zoölogy - Reese, A. M. (Albert Moore), 1872 -1965 (P. Blakiston's Son & Co, 1919)

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