On the classification and geographical distribution of the Mammalia, being a lecture on Sir Robert Reade's foundation, delivered before the University of Cambridge ... May 10, 1859. To which is added an appendix "On the gorilla," and "On the extinction and transmutation of species." - Owen, Richard, 1804 -1892 (J. W. Parker and son, 1859)

On the distribution of birds in Great Britain, during the nesting season - More, Alexander Goodman, 1830 -1895 (British Ornithologists' Union, 1865)

On the earlier notices relative to the natural history of the giraffe - Holme, Frederic (Printed by S. Collingwood, for the Ashmolean Society, 1838)

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 instincts and habits of the solitary wasps - Peckham, Elizabeth G. (Elizabeth Gifford), 1854 -1940 (Published by the state, 1898)

On the natural history and classification of birds - Swainson, William, 1789 -1855 (John Taylor, 1836)

On the Natural History and classification of Birds : vol. I and II - Swainson, William, 1789 -1855 (pr. for Longman [etc.], 1836)

On the nidification of the winter wren in Nova Scotia - Piers, Harry, 1870 -1940 (s.n, 1892)

On the origin of species - Darwin, Charles, 1809 -1882 (D. Appleton and Co, 1871)

On the origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (Henry Frowde, 1907)

On the origin of species by means of natural selection; or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Co, 1860)

On the origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, Albemarle Street, 1859)

On the origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1860)

On the origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1859)

On the origin of species by the means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (Odhams Press, 1872)

On the plains, and among the peaks, or, How Mrs. Maxwell made her natural history collection - Ridgway, Robert, 1850 -1929 (Claxton, Remsen & Haffelfinger, 1879)

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)

Onomasticon zoicon, plerorumque animalium differentias & nomina propria pluribus linguis exponens : cui accedunt Mantissa anatomica, et quaedam De variis fossilium generibus - Charleton, Walter, 1619 -1707 (Apud Jacobum Allestry ..., 1668)

Onze vogels in huis en tuin - Keulemans, J. G. (John Gerrard), 1842 -1912 (P.W.M. Trap, 1869)

The oölogist (J.M. Wade, 1877)

The oölogist (J.M. Wade, 1879)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1886)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1887)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1889)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1890)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1891)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1907)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1908)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1911)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1914)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank Haak), 1861 -1937 (Frank H. Lattin, 1916)

Ootheca Wolleyana: an illustrated catalogue of the collection of birds' eggs - Newton, Alfred, 1829 -1907 (sold by R. H. Porter, 1902)

Opera ornithologica - Bonaparte, Charles-Lucien, 1803 -1857 (1857)

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, 1958)

Opuscula ornithologica : notis et addendis, mss - Coues, Elliott, 1842 -1899 (1861)

Opuscules entomologiques - Mulsant, Martial Étienne, 1797 -1880 (L. Maison, 1853)

Orang-outang, sive homo sylvestris: or, The anatomy of a pygmie compared with that of a monkey, an ape, and a man. To which is added, A philological essay concerning the pygmies, the cynocephali, the satyrs, and sphinges of the ancients. Wherein it will appear that they are all either apes or monkeys, and not men, as formerly pretended - Tyson, Edward, 1650 -1708 (Printed for T. Bennett and D. Brown, and are to be had of Mr. Hunt, 1699)

Orange culture : a treatise on the citrus family - Gallesio, Giorgio, 1772 -1839 (Printed at the Office of "The Florida Agriculturist,", 1876)

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)

The Orchid review (Orchid Review ltd.], 1893)

The Orchid review (Orchid Review ltd.], 1903)

The Orchid review (Orchid Review ltd.], 1906)

The Orchid review (Orchid Review ltd.], 1913)

Orchidophile; journal des amateurs d'orchideés - Godefroy-Lebeuf, A. (Alexandre), 1844 -1903 (1881)

Orchids for everyone - Curtis, Charles H. (J.M. Dent, 1910)

Orchis :Monatsschrift der Deutschen Gesellschaft für Orchideenkunde - Dammer, Udo. (1906)

The Oregon naturalist (Naturalist Pub. Co, 1896)

Organic evolution considered - Fairhurst, Alfred, 1843 -1921 (Christian publishing, 1897)

The origin and influence of the thoroughbred horse - Ridgeway, William, Sir, 1853 -1926 (University Press, 1905)

The origin of species - Darwin, Charles, 1809 -1882 (Books, Inc, 1900)

The origin of species - Darwin, Charles, 1809 -1882 (Literary Classics, 1900)

The origin of species - Darwin, Charles, 1809 -1882 (P.F. Collier, 1909)

The origin of species by means of natural selecti : or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (1904)

The origin of species by means of natural selection, or, the preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1872)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (John Murray, 1880)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1888)

The origin of species by means of natural selection; or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1886)

The origin of species by means of natural selection : or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (Merrill and Baker, 1900)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (A.L. Burt, 1899)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (A.L. Burt, 1894)

The origin of species by means of natural selection; or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1909)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton, 1899)

The origin of species by means of natural selection; or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1889)

The origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and Company, 1917)

The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (J. Murray, 1902)

The origin of species by means of natural selection : or The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (Hurst, 1872)

The origin of species by means of natural selection; or, the preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton and company, 1915)

Origin of species by means of natural selection, or, The preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (P. F. Collier, 1902)

Origin of species by means of natural selection, or the preservation of favored races in the struggle for life - Darwin, Charles, 1809 -1882 (P. F. Collier, 1905)

Origin of species - Darwin, Charles, 1809 -1882 (H.M. Caldwell Co, 1900)

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)

The origin of the species by means of natural selection - Darwin, Charles, 1809 -1882 (J. Murray, 1910)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1885)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1886)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1887)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1888)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1891)