The most important parts of the Museum of Natural History are the Conchological division and the collection of ammonites.
"The South of France--East Half"
Charles Bertram Black
But the reader must bear in mind that the terms Eocene, Miocene, and Pliocene were originally invented with reference purely to Conchological data, and in that sense have always been and are still used by me.
"The Student's Elements of Geology"
Sir Charles Lyell
If, therefore, the relative ages of the Picardy and Natchez alluvium were to be decided on Conchological data alone, the fluvio-marine beds of Abbeville might rank as a shade older than the loess of Natchez.
"The Antiquity of Man"
Charles Lyell