Correlation papers ; Cambrian /
Walcott, Charles D. 1850-1927.
Correlation papers ; Cambrian / by Charles Doolittle Walcott. - Washington, Govt. Print. Off., 1891. - 447 p. : iii fold. maps, diagrs. ; 24 cm. - U.S. Geological survey. Bulletin no. 81 . - United States. Geological Survey. Bulletin ; 81. .
Literature : p. 19-48.
gs 05000660
Geology, Stratigraphic--Cambrian.
Geology--United States.
QE75 / .B9 no. 81
Correlation papers ; Cambrian / by Charles Doolittle Walcott. - Washington, Govt. Print. Off., 1891. - 447 p. : iii fold. maps, diagrs. ; 24 cm. - U.S. Geological survey. Bulletin no. 81 . - United States. Geological Survey. Bulletin ; 81. .
Literature : p. 19-48.
gs 05000660
Geology, Stratigraphic--Cambrian.
Geology--United States.
QE75 / .B9 no. 81