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, 1956)

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, 1957)

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, 1943)

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, 1944)

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, 1945)

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, 1939)

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, 1954)

Opuscula subseciva, observationes miscellaneas de animalculis et plantis quibusdam marinis, eorumque ovariis et seminibus continentia - Baster, Job, 1711 -1775 (apud J. Bosch, 1762)

Ornis - International Ornithological Committee. (Carl Gerold's Sohn, 1889)

Ornithologisches Jahrbuch (V. Tschusi, 1910)

The Ornithologist and oölogist (1886)

Orthoptera (Acridiidae) - Kirby, W. F. (William Forsell), 1844 -1912 (Taylor and Francis ; [etc., etc.], 1914)

Orthoptera descripta et depicta - Charpentier, Toussaint von, 1779 -1847 (Leop. Voss, 1841)

Orthoptera Helvetiae : analytisch bearbeitet als Grundlage einer Orthopterenfauna der Schweiz - Schoch, Gustav, 1833 -1899 (Druck von F. Rothermel, 1886)

The Orthoptera of Indiana : an illustrated descriptive catalogue of the species known to occur in the state, with bibliography, synonymy and descriptions of new species - Blatchley, W. S. (Willis Stanley), 1859 -1940 ([Indiana Dept. of Geology and Natural Resources, 1903)

Orthoptera of Maine - Morse, Albert P. (Albert Pitts), 1863 -1936 (Maine Agricultural Experiment Station, 1921)

The Orthoptera of New England. Designed for the use of the students in the Massachusetts agricultural college and the farmers of the state - Fernald, C. H. (Charles Henry), 1838 -1921 (Wright & Potter printing company, 1888)

Orthoptera of northeastern America, with especial reference to the faunas of Indiana and Florida - Blatchley, W. S. (Willis Stanley), 1859 -1940 (The Nature Publishing Company, 1920)

Orthoptera of northeastern America : with especial reference to the faunas of Indiana and Florida - Blatchley, W. S. (Willis Stanley), 1859 -1940 (Nature Pub. Co., 1920, 1920)

Osservazioni naturali intorno alle cavallette nocive della Campagna Romana / [da Luigi Metaxa e Sebastiano Rolle] - Rolle, Sebastiano, (Vincenzo Poggioli, 1825)

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)

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 creation - Noyce, Elisha. (Ward & Lock, 1858)

Outlines of entomology - Murtfeldt, Mary Esther, 1848 -1913 (Tribune Printing Company, State Printers and Binders, 1891)

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

Outlines of the natural history of Great Britain and Ireland, containing a systematic arrangement and concise description of all the animals, vegetables and fossiles which have hitherto been discovered in these kingdoms - Berkenhout, John, 1730 -1791 (Printed for P. Elmsly (Successor to Mr. Vaillant), 1769)

Oversigt over det vestilge Grønlands fauna af malakostrake Havkrebsdyr - Hansen, H. J. (Hans Jacob), 1855 -1936 ([Bianco Luno], 1887)

P. Boddaert, med. doct. urbis Ulissingæ exconsiliarii ... Elenchus animalium, volumen I : sistens quadrupedia huc usque nota, eorumque varietates : ad ductum naturae, quantum fieri potuit disposita - Boddaert, Pieter, 1730 -1795 (Apud C.R. Hake, 1784)

P.A. Latreille scientiarum et artium instituti Gallici ... Genera crustaceorum et insectorum : secundum ordinem naturalem in familias disposita, iconibus exemplisque plurimis explicata - Latreille, P. A. (Pierre André), 1762 -1833 (Apud Amand Knig, Bibliopolam, 1806)

P.A. Latreille scientiarum et artium instituti Gallici ... Genera crustaceorum et insectorum : secundum ordinem naturalem in familias disposita, iconibus exemplisque plurimis explicata - Latreille, P. A. (Pierre André), 1762 -1833 (Apud Amand Knig, Bibliopolam, 1807)

P.A. Latreille scientiarum et artium instituti Gallici ... Genera crustaceorum et insectorum : secundum ordinem naturalem in familias disposita, iconibus exemplisque plurimis explicata - Latreille, P. A. (Pierre André), 1762 -1833 (Apud Amand Knig, Bibliopolam, 1809)

Palaeontographica (Theodor Fischer, 1861)

Palaozoologie : Entwurf einer systematischen Darstellung der Fauna der Vorwelt - Giebel, C. (Christoph), 1820 -1881 (Nulandt'sche buchandlung (L. Garcke), 1846)

Palestine : the physical geography and natural history of the Holy Land - Kitto, John, 1804 -1854 (Charles Knight, 1841)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1895)

Pamietnik Fizyjograficzny (Druk K. Kowalewskiego, 1914)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1977)

The Pan-Pacific entomologist - Van Duzee, Edward P. (Edward Payson), 1861 -1940 (Pacific Coast Entomological Society, 1990)

Papéis avulsos do Departamento de Zoologia - São Paulo Departamento de Zoologia (A Secretaria, 1947)

Papers from the Tortugas Laboratory of the Carnegie Institution of Washington - Carnegie Institution of Washington. Department of Marine Biology. (Carnegie Institution of Washington, 1914)

Papers on Diptera - Aldrich, John Merton, 1866 -1934 (Smithsonian Institution, 1913)

Les parasites des habitations humaines et des denrees alimentaires ou commerciales - Trouessart, E.-L. (Edouard-Louis), 1842 -1927 (G. Masson, 1895)