Page:Walcott Cambrian Geology and Paleontology II.djvu/17



In accepting the invitation of the Representatives for Paleontology of the Swedish Committee of the Eleventh International Geological Congress, to take part in the discussion of "The Abrupt Appearance of the Cambrian Fauna," I decided to confine the geological discussion mainly to phenomena observed on the North American Continent and to limit paleontological conclusions to results obtained from studies of material from the oldest fossiliferous Cambrian rocks.

In summing up the Lower Cambrian fauna in 1891 [Walcott,