The New Mexico botanist - New Mexico State University. Cooperative Extension Service. (Range Science Herbarium and Cooperative Extension Service, 2010)

The New Mexico botanist - New Mexico State University. Cooperative Extension Service. (Range Science Herbarium and Cooperative Extension Service, 2015)

A new species of leech from the New York metropolitan area - Siddall, Mark Edward, 1966 - (American Museum of Natural History, 2007)

A new species of leopard frog (Rana pipiens complex) from the Plains of the central United States - Mecham, John S. (The Museum, Texas Tech University, 1973)

New Zealand Mud Snails in the Darlington Ditch, Cobblestone Fishing Access Site on the Madison River - Montana. Department of Fish, Wildlife,; Parks (Montana Fish, Wildlife & Parks, 2001)

Nomenclator zoologicus : continens nomina systematica generum animalium tam viventium quam fossilium, secundum ordinem alphabeticum disposita, adjectis auctoribus, libris, in quibus reperiuntur, anno editionis, etymologia et familiis, ad quas pertinent, in singulis classibus - Agassiz, Louis, 1807 -1873 (Jent et Gassmann, 1842)

Nomenclatoris zoologici index universalis : continens nomina systematica classium, ordinum, familiarum et generum animalium omnium ... homonymiis plantarum - Agassiz, Louis, 1807 -1873 (Sumptibus Jent et Gassman, 1848)

Nomina systematica generum reptilium, tam viventium quam fossilium : secundum ordinem alphabeticum disposita, adjectis auctoribus, libris in quibus reperiuntur, anno editionis, etymologia et familiis ad quas pertinent - Agassiz, Louis, 1807 -1873 (s.n, 1844)

North American fauna - U.S. Fish; Wildlife Service (Fish and Wildlife Service; for sale by the Supt. of Docs., U. S. Govt. Print. Off, 1975)

The North Queensland Naturalist : the journal and magazine of the North Queensland Naturalist Club - North Queensland Naturalists' Club. (The Club, 1971)

Northern leopard frog reintroduction : year 3 (2001) - Alberta. Fish; Wildlife Division. (Alberta Sustainable Resource Development, Fish & Wildlife Division, Resource Status and Assessment Branch, 2002)

Nota lepidopterologica - Societas Europaea Lepidopterologica (2010)

Nova Guinea : résultats de l'expédition scientifique néerlandaise à la Nouvelle-Guinée ... - Beaufort, L. F. de (Lieven Ferdinand), 1879 -1968 (E.J. Brill, 1906)

Nova Guinea : résultats de l'expédition scientifique néerlandaise à la Nouvelle-Guinée ... - Beaufort, L. F. de (Lieven Ferdinand), 1879 -1968 (E.J. Brill, 1917)

Nova Guinea : résultats de l'expédition scientifique néerlandaise à la Nouvelle-Guinée ... - Beaufort, L. F. de (Lieven Ferdinand), 1879 -1968 (E.J. Brill, 1909)

Novitates zoologicae : a journal of zoology in connection with the Tring Museum - British Museum (Natural History) (Zoological Museum, 1940)

Nuovi annali delle scienze naturali (1838)

Nuovi annali delle scienze naturali (1840)

Nuovi annali delle scienze naturali (1852)

Occasional papers - Boston Society of Natural History. (1904)

Occasional papers - Texas Tech University. Museum, (The Museum, 1988)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1921)

Occasional papers of the Boston Society of Natural History - Boston Society of Natural History. (Boston Society of Natural History, 1904)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1928)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1970)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1973)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1974)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 1984)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2010)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2012)

Occasional papers of the California Academy of Sciences - California Academy of Sciences (California Academy of Sciences, 2013)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1975)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1976)

Occasional papers of the Museum of Natural History, the University of Kansas - University of Kansas. Museum of Natural History. (The University, 1985)

Occasional papers of the Museum of Zoology, University of Michigan - University of Michigan. Museum of Zoology. (University of Michigan, 1917)

Occasional papers of the Natural History Museum, the University of Kansas, Lawrence, Kansas - University of Kansas. Museum of Natural History. (The University, 1996)

Occasional papers of the San Diego Society of Natural History - San Diego Society of Natural History. (San Diego Society of Natural History, 1964)

Ohio Biological Survey notes - Ohio Biological Survey. (Ohio Biological Survey, 2011)

Ohio Biological Survey notes - Ohio Biological Survey. (Ohio Biological Survey, 2019)

Ohio Biological Survey notes - Ohio Biological Survey. (Ohio Biological Survey, 2021)

Ohio fossils - La Rocque, Aurèle, 1909 -1990 (Ohio Dept. of Natural Resources, Division of Geological Survey, 1955)

On Atopophrynus, a recently described frog wrongly assigned to the Dendrobatidae - Myers, Charles W. (American Museum of Natural History, 1986)

On the reptiles and Batrachians of North America - Garman, Samuel, 1843 -1927 (Major, Johnston & Barrett, Yeoman, 1883)

On the structure and development of the skull in the Batrachia - Royal Society (Great Britain) (Royal Society, 1881)

On the type specimens of two Colombian poison frogs described by A.A. Berthold (1845), and their bearing on the locality "Provinz Popayan" - Berthold, Arnold Adolph, 1803 -1861 (American Museum of Natural History, 1996)

De ontwikkeling van het chondrocranium van Alytes obstetricans voor de metamorphose - Seters, Wouter Hendrik van. ("Het Klaverblad", 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)

O.S.U. naturalist - Ohio State University. Biological Club. (Biological Club of Ohio State University, 1901)

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)

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

Outlines of zoology - Thomson, J. Arthur (John Arthur), 1861 -1933 (Humphrey Milford, Oxford University Press, 1929)

Over de ontwikkeling van het chondrocranium en de kraakbeenige wervelkolom van eenige Urodela en Anura - Peeters, Johannes Leonardis Elbertus. (G.F. Theonville, 1910)

Pacific science - University of Hawaii. (University Press of Hawaii, 1950)

Palaeontology - Palaeontological Association (Palaeontological Association, 1990)

Palaeontology - Palaeontological Association (Palaeontological Association, 1998)

Paleocene amphibians from Cernay, France - Estes, Richard (American Museum of Natural History, 1967)