"Mr. Austen's communication [was] read December 1837 ... It was immediately after the reading of that paper...that I formed the opinion relative to the limestones of Devonshire being of the age of the old red sandstone; and which I afterwards suggested first to Mr. Murchison and then to Prof. Sedgwick" (p. 724): William Lonsdale, "Notes on the age of limestones from south Devonshire" in Transactions of the Geological Society of London 2a ser. vol. 5 (1840) (pp. 721–738 apud Google Books)
"Again, Mr. Lonsdale, after an extensive examination of the fossils of South Devon, had pronounced them, more than a year since, to form a group intermediate between those of the Carboniferous and Silurian systems" (p. 690); "We propose therefore, for the future, to designate these groups collectively by the name Devonian system" (p. 701): Adam Sedgwick, R. I. Murchison, "On the physical structure of Devonshire, and on the subdivisions and geological relations of its older stratified deposits" in Transactions of the Geological Society of London 2a ser. vol. 5 (1840) (pp. 633–705 apud Google Books)
De historia nominis definitionisque vide: Mary Grace Wilmarth, The Geologic Time Classification of the United States Geological Survey Compared With Other Classifications, accompanied by the original definitions of era, period and epoch terms (United States Geological Survey Bulletin no. 769. Vasingtoniae: U.S. Government Printing Office, 1925) (Textus apud Google Books)
