Correlation papers Cambrian Walcott, Charles D. (Charles Doolittle) 1850-1927 creator author. Geological Survey (U.S.) issuing body. text bibliography dcu 1891 monographic eng remote 1 online resource (447 pages) : illustrations, maps. by Charles Doolittle Walcott. Title from title screen (viewed June 2, 2015). Includes bibliographical references and index. n-us--- From 500 to 570 million years ago fast Geology, Stratigraphic Cambrian Geology United States Cambrian Geologic Period Geology Geology, Stratigraphic United States I 19.3:81 I 19.3:81 Correlation papers: Cambrian Walcott, Charles D. (Charles Doolittle), 1850-1927. (DLC)gs 05000660 (OCoLC)4986479 Bulletin of the United States Geological Survey ; no. 81 https://purl.fdlp.gov/GPO/gpo58070 OCLCE 111111 20211120173121.0 in00003597361 eng