TERTIARY Headon Series and beds between the Paris Gypsum and the Grès de Beauchamp 14 10 English 4 French Barton Clay and Sables de Beauchamp 0 Bagshot Beds, Calcaire Grossier, and Upper Soissonnais of Cuisse-Lamotte 20 16 French 1 English 3 U. States[2] London Clay, including the Kyson Sand 7 English Plastic Clay and Lignite 9 7 French 2 English Sables de Bracheux 1 French Thanet Sands and Lower Landenian of Belgium 0 SECONDARY Maestricht Chalk 0 White Chalk 0 Chalk Marl 0 Chloritic Series (Upper Greensand) 0 Gault 0 Neocomian (Lower Greensand) 0 Wealden 0 Upper Purbeck Oolite 0 Middle Purbeck Oolite 14 Swanage Lower Purbeck Oolite 0 Portland Oolite 0 Kimmeridge Clay 0 Coral Rag 0 Oxford Clay 0 Great Oolite 4 Stonesfield Inferior Oolite 0 Lias 0 Upper Trias 4 Wurtemberg Somersetshire N. Carolina Middle Trias 0 Lower Trias 0 PRIMARY Permian 0 Carboniferous 0 Devonian 0 Silurian 0 Cambrian 0 Laurentian 0 The Sables de Bracheux, enumerated in the Tertiary division of the table, supposed by Mr. Prestwich to be somewhat newer than the Thanet Sands, and by M. Hébert to be of about that age, have yielded at La Fere the _Arctocyon (Palæocyon) primævus,_ the oldest known tertiary mammal. It is worthy of notice, that in the Hastings Sands there are certain layers of clay and sandstone in which numerous footprints of quadrupeds have been found by Mr. Beckles, and traced by him in the same set of rocks through Sussex and the Isle of Wight. They appear to belong to three or four species of reptiles, and no one of them to any warm-blooded quadruped. They ought, therefore, to serve as a warning to us, when we fail in like manner to detect mammalian footprints in older rocks (such as the New Red Sandstone), to refrain from inferring that quadrupeds, other than reptilian, did not exist or pre-exist.