The North American continent during Cambrian time /
Walcott, Charles D. 1850-1927.
The North American continent during Cambrian time / by Charles D. Walcott. - Washington, Gov't. print. off., 1892. - 523-568 p. pl. XLII-XLV (incl. double maps) diagrs. 31 cm.
Cover title. Extract from the 12th annual report of the director of the U.S. Geological survey, 1890-91, pt. I.
gs 06001021
Geology, Stratigraphic--Cambrian.
Geology--North America.
QE656 / .W2
The North American continent during Cambrian time / by Charles D. Walcott. - Washington, Gov't. print. off., 1892. - 523-568 p. pl. XLII-XLV (incl. double maps) diagrs. 31 cm.
Cover title. Extract from the 12th annual report of the director of the U.S. Geological survey, 1890-91, pt. I.
gs 06001021
Geology, Stratigraphic--Cambrian.
Geology--North America.
QE656 / .W2