In the lowest beds of gravel and sand in contact with the Chalk, flint hatchets, some perfect, others much rolled, have been found; and in a sandy bed in this position some workmen, whom I employed to sink a pit, found four flint knives. Above this sand and gravel occur beds of white and siliceous sand, containing shells of the genera Planorbis, Limnea, Paludina, Valvata, Cyclas, Cyrena, Helix, and others, all now natives of the same part of France, except Cyrena fluminalis (Figure 17), which no longer lives in Europe, but inhabits the Nile, and many parts of Asia, including Cashmere, where it abounds. No species of Cyrena is now met with in a living state in Europe. Mr. Prestwich first observed it fossil at Menchecourt, and it has since been found in two or three contiguous sand-pits, always in the fluvio-marine bed. [16] [Illustration: Figure 17. Cyrena fluminalis] (FIGURE 17. Cyrena fluminalis, O.F. Muller, sp.* (* For synonyms, see S. Woodward "Tibet Shells" "Proceedings of the Zoological Society" July 8, 1856.) a. Interior of left valve, from Gray's Thurrock, Essex. b. Hinge of the same magnified. c. Interior of right valve of a small specimen, from Shacklewell, London. d. Outer surface of right valve, from Erith, Kent.) TABLE 8/1. DATES OF SPECIFIC NAMES. COLUMN 1: SPECIES. COLUMN 2: DATE. LIVING: Tellina fluminalis, O.F. Muller: 1774. Venus fluminalis Euphratis, Chemnitz: 1782. Cyclas Euphratica, Lam.: 1806. Cyrena cor, Lam. (Nile): 1818. Cyrena consobrina, Caillaud (Nile): 1823. Cyrena Cashmiriensis, Desh.: Corbicuia fluminalis, Muhlfeldt.: 1811. FOSSIL: Cyrena trigonula, S. Woodward: 1834. Cyrena Gemmellarii, Philippi: 1836. Cyrena Duchastelii, Nyst: 1838. The following marine shells occur mixed with the freshwater species above enumerated:--Buccinum undatum, Littorina littorea, Nassa reticulata, Purpura lapillus, Tellina solidula, Cardium edule, and fragments of some others. Several of these I have myself collected entire, though in a state of great decomposition, lying in the white sand called "sable aigre" by the workmen. They are all littoral species now proper to the contiguous coast of France. Their occurrence in a fossil state associated with freshwater shells at Menchecourt had been noticed as long ago as 1836 by MM. Ravin and Baillon, before M. Boucher de Perthes commenced the researches which have since made the locality so celebrated.* (* D'Archiac, "Histoire des Progres" etc. volume 2 page 154.) The numbers since collected preclude all idea of their having been brought inland as eatable shells by the fabricators of the flint hatchets found at the bottom of the fluvio-marine sands. From the same beds, and in marls alternating with the sands, remains of the elephant, rhinoceros, and other mammalia have been exhumed.