No Cambrian area in all eastern North America is more interesting stratigraphically, or shows more complicated structure, than that of northwestern Vermont and the adjacent portion of New York. Even after nearly a century of endeavor, it cannot be said that the entire sequence of the formations is now known, and it will not be satisfactorily adjusted until the succession of the formations in the Eastern Sequence of northwestern Vermont is also unraveled. The present paper is restricted to the Cambrian and Lower Ordovician stratigraphy and faunas of the Central Sequence of the northwestern part of Vermont (Fig. 1), as originally defined by Keith. The Upper Cambrian and Ordovician stratigraphy as now presented varies considerably from that given by the writer in 1933.1
The rise of modern geology in New York and Vermont may be said to have begun at least one hundred years ago,2 . . .