TY  - BOOK
AU  - Walcott,Charles D.
TI  - The North American continent during Cambrian time
AV  - QE656 .W2
PY  - 1892///
CY  - Washington
PB  - Gov't. print. off.
KW  - Geology, Stratigraphic
KW  - Cambrian
KW  - Geology
KW  - North America
N1  - Cover title; Extract from the 12th annual report of the director of the U.S. Geological survey, 1890-91, pt. I
ER  -