Please refer to the geological map of the Massif Armoricain, displaying the geology of Bretagne, Normandy and the adjacent part of France, and clearly showing the Oligocene outcrop near Rennes, the Oligocene and Eocene of Loire-Atlantique as well as the various deposits of the western part of the Paris Basin.
The Eocene of France contains one of the best documented molluscan faunas known. Since the early days of palaeontology, fossils from the Paris basin have been documented and named, starting with Lamarck who described the most common species. Cossmann & Pissarro (1913) illustrated all olivids known from the Eocene of the Paris Basin at that time. Recent studies indicate that the French Eocene faunas are much more diverse than previously noticed.
Eocene faunas from the Ypresian, Bartonian (Oise, Baron) and Priabonian, are documented from France.
A list of collecting sites in the Paris Basin Lutetian (updated mollusca taxonomy see Merle, 2008) can be found on the Internet (Anonymous, 2016). Those sites are copied here, with hyperlinks added to sites from which materials are added to the specimens database:
| Departement | Sites |
| Aisne |
Aubigny Breny La Neuville-en-Beine Ferme de Vimoutié La Maison Rouge Pargnan Saint-Gobain Troesnes-sur-Ourcq |
| Aube | Nogent-sur-Seine |
| Eure |
Ecos Guitry Pacy-sur-Eure |
| Eure et Loir |
Berchères-sur-Vesgres Saint-Lubin de la Haye |
| Marne |
Damery Epernay Ferme de Courtagnon Reims |
| Oise |
Chantilly Chaumont-en-Vexin Cuise-la-Motte Fosse Le Vivray Le Regard-de-Coye Liancourt-Saint-Pierre Mouchy-le-Chatel Parnes Ponchon Pont-Sainte-Maxence Saint-Leu d'Esserent Saint-Maximin Saint-Vaast de Longmont Vaudancourt |
| Paris |
Passy Vaugirard |
| Seine et Marne |
Crouy-sur-Ourcq La Poterie Lizy-sur-Ourcq May-en-Multien Marnoue-la-Poterie Montereau Provins Vernelles |
| Yvelines |
Ferme de l'Orme Grignon Houdan Montainville Renonville Thionville-sur-Opton Tessancourt |
| Hauts-de-Seine |
Bagneux Chatillon Clamart Gentilly Issy-les-Moulineaux Nanterre Vanves |
| Val-de-Marne |
Arcueil-Cachant Champigny-sur-Marne Créteil Ivry-sur-Seine Noisy-le-Sec Villejuif |
| Val d'Oise |
Chaussy La Frette Le Fayel Pierrelaye Pontoise Saint Ouen l'Aumone Vallangoujard Valmondois |
| Loire-Atlantique | Le Bois Gouët (situated in the Loire Basin, not the Paris Basin, but similar from a palaeoecological point of view) |
| Manche |
Fresville Hauteville Orglandes Valognes |
| Calvados | Bayeux |