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 skeleton of Toxochelys latiremis - Hay, Oliver Perry, 1846 -1930 (1896)

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 relations of Notharctus, an American eocene primate - Gregory, William K. (William King), 1876 -1970 (1920)

On Vertebrata of the Mid-Cretaceous of the North West Territory - Geological Survey of Canada (Govt. Print. Bureau, 1902)

On vertebrata of the mid-Cretaceous of the North West Territory - Geological Survey of Canada (Govt. Print. Bureau, 1902)

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

The orders of mammals - Gregory, William K. (William King), 1876 -1970 (The Trustees, 1910)

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

Ordosemys (Testudines, Cryptodira) from the Yixian Formation of Liaoning Province, northeastern China : new specimens and systematic revision - Ji, Shu-An. (American Museum of Natural History, 2004)

Organic evolution as the result of the inheritance of acquired characters according to the laws of organic growth - Eimer, Theodor, 1843 -1898 (Macmillan, 1890)

The origin and evolution of life : on the theory of action, reaction and interaction of energy - Osborn, Henry Fairfield, 1857 -1935 (Scribner's, 1918)

The origin and evolution of life, on the theory of action, reaction and interaction of energy - Osborn, Henry Fairfield, 1857 -1935 (C. Scribner's Sons, 1917)

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 selection, or, The preservation of favoured races in the struggle for life - Darwin, Charles, 1809 -1882 (D. Appleton & Co, 1889)

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 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 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 (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, 1915)

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)

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 (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)

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

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)

Ostéographie, ou, Description iconographique comparée du squelette et du système dentaire des Mammifères récents et fossiles : pour servir de base à la zoologie et à la géologie - Blainville, H.-M. Ducrotay de (Henri-Marie Ducrotay), 1777 -1850 (J.B. Baillière et fils, 1839)

Osteology of pteranodon - Eaton, George Francis, 1872 - (1910)

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

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1899)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1905)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1906)

The Ottawa naturalist - Ottawa Field-Naturalists' Club (Ottawa Field-Naturalists' Club, 1908)

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 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)