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 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 cranial osteology, classification and phylogeny of Dinornithidae - Parker, T. Jeffery (Thomas Jeffery), 1850 -1897 (1895)

On the identification of Meckelian and mylohyoid grooves in the jaws of Mesozoic and recent Mammalia - Bensley, B. A. (Benjamin Arthur), 1875 -1934 (The University Library, published by the Librarian, 1902)

On the marsupial pouches, mammary glands and mammary foetus of the Echidna hystrix - Owen, Richard, 1804 -1892 (Royal Society of London, 1865)

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 nature of the granule cells of paneth in the intestinal glands of mammals - Klein, Sidney (1906)

On the phenomena of variation and geographical distribution as illustrated by the Papilionidae of the Malayan region. Read March 17, 1864 - Wallace, Alfred Russel, 1823 -1913 (1865)

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

Ophidia taprobanica; or, The snakes of Ceylon - Wall, Frank, 1868 -1950 (H.R. Cottle, govt. printer, 1921)

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)

The Orchid review (Orchid Review ltd.], 1902)

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

Orchids: their culture and management - Watson, William, 1858 -1925 (L. U. Gill, 1903)

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

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 life and process of reproduction in plants and animals : with the anatomy and physiology of the human generative system, male and female, and the causes, prevention and cure of the special diseases to which it is liable : a plain, practical treatise, for popular use - Hollick, Frederick, 1818 -1900 (David McKay, 1902)

Ornithological Field Diaries of A. Graham Brown - Brown, Arthur Graham, 1919 -1982 (1949)

Ornithological Field Diaries of A. Graham Brown - Brown, Arthur Graham, 1919 -1982 (1950)

Ornithological Field Diaries of A. Graham Brown - Brown, Arthur Graham, 1919 -1982 (1956)

Ornithorhynchi paradoxi descriptio anatomica - Meckel, J. F. (Johann Friedrich), 1781 -1833 (1826)

Ostéographie des monotrèmes vivants et fossiles comprenant la description et l'iconographie du squelette et du système dentaire de ces animaux ainsi que des documents relatifs à leur histoire naturelle - Gervais, Paul, 1816 -1879 (A. Bertrand, 1878)

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

Our face from fish to man; a portrait gallery of our ancient ancestors and kinsfolk together with a concise history of our best features - Gregory, William K. (William King), 1876 -1970 (G.P. Putnam's Sons, 1929)

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)

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

Outlines of chordate development - Kellicott, William E. (William Erskine), 1878 -1919 (Holt, 1913)

Outlines of chordate development - Kellicott, William E. (William Erskine), 1878 -1919 (H. Holt and company, 1913)

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

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