GUETTARD, JEAN ÉTIENNE. - A LANDMARK PAPER IN PALAEONTOLOGY.

Mémoire sur les Ardoisiéres D'Angers.

(Paris, L'Imprimerie Royale, 1762). 4to. Without wrappers. Extracted from "Mémoires de l'Academie des Sciences. Année 1757". Pp. 52-86 and 7 folded engraved plates. Clean and fine.

First edition of this landmark paper in geological literature, for it appeared eighty years before Murchison's Silurian System made known the sequence and abundant organic remains of the Silurian rocks of Wales.
"Guettard was the first to recognize trilobites in the Silurian slates of Angers. In some specimens which had been sent up to the Academy from the quarries of that district, he observed numerous impressions of organic remains, which he referred to seaweeds and Crustacea. The latter he sagaciously compared 25 to modern crabs and prawns." (Archibald Geikie).
Parkinson "Breakthroughs", 1757.

Order-nr.: 51333