Note 023 — Chapter I

Drake's Picture of Cincinnati, page 64. To that work, Cranmer's [Cramer's] "Navigator," published at Pittsburgh in 1814, and Gilleland's "Ohio and Mississippi Pilot," we refer our readers for very minute, and in general very accurate, accounts of the country along the Ohio.—James.

Comment by Ed. This area, known to geologists as the "Cincinnati anticline," is co-extensive with the fertile blue grass lands. It consists essentially of an island of Ordovician (Lower Silurian) limestone, surrounded by the later systems. The Ordovician system is especially characterized by mollusca of the cephalopod class, to which Orthoceras belongs, while the Ammonites do not appear below the Devonian.