26 THE EOCENE BEDS 



calcareous. The Sd.ndiS {Sables de Beaiichamp) are extraordinarily 

 fossiliferous, amongst other places, at Le Guepelle, Beauchamp and 

 Verneuil ; considerably more than two hundred species have been 

 recorded from the last-named locality alone. The sandstone 

 (Gres de Beauchamp) is quarried in many places for pavings. At 

 Lizy-sur-Ourcq a siliceo-calcareous freestone {Pierre de Lizy) is 

 worked from this horizon, t 



The classical section for this horizon is no longer visible ; but 

 the details are given in the paper just referred to. To the east 

 of Herblay, close to Paris in the wood of Boissy, other sections 

 have since been exposed. 



The following is a general section of the beds in this neigh- 

 bourhood, from Dr. Hovelacque's notes : — 



Gefieral Section at Beauchamp. 



9. Marly limestone, white, more or less remanie (St. ft. in. 



Ouen limestone) with small Bithinia . . . 10 o 



8. Bed with Avicu/a Defrancei ..... ? 



7. Brownish marls with flint in " plaquettes," and 



Ampullina (Ducy limestone) ..... 20 



6. Hard lithographic limestone, small Bithinia . . 13 



5. Yellow marls ........ 13 



4. White sands with Bayania hordacea .... 9 



3. Brown sandstone ....... ? 



2. Brown sands ........ 33 



I. White sands, pure, very fossiliferous, containing 



Bayania liordacea^ Potamides Boiiei, P deperditus, 



MereU'tx elegans and Corbicitla deperdita . 



One of the best sections now open in this horizon is that on 

 the road to Ermenonville, near Ver, and the section is named 

 from the latter town (fig. 9, p. 27). 



A few other characteristic fossils of the true marine beds of 

 the horizon of Beauchamp are Potamides scaiaroides, P. Boiuiardi, 

 Cerithium crenatulatum, Cancellaria evulsa, Alelongena subcarinata, 

 Xenophora agglutitta?is, Area biangula and Meretrix h^vigata. 



The upper portion of this horizon of the Sables Moyens is 

 characterised in some districts by the intercalation of a fresh- 

 water limestone {Calcaire de Ducy, Naiiteuil, &c.) containing 

 Bithinia tuba, Limncea arenularia and others; this has some analogy 

 on the one hand with the fauna of the Sands of Beauchamp, and 

 on the other with the St. Ouen Limestone ; the fresh-water 

 conditions increase as the upper beds of the Sables Moyens are 

 reached, until a distinctly lacustrine series is met with in the St. 

 Ouen Limestone. 



Upper Sables Moyens (Horizon of Mortefontaine). — 

 The upper part of the Sables Moyens consists of an alternating 

 series of sands more or less argillaceous in part, and thin-bedded 

 limestones with a distinctive and varied series of fossil remains. 



t A section at this locality is given by G. Dollfus in Contrib. a la Stratig. Parisienne ; 

 BuU. Soc.Geol. Fr., 30. s^r., t. viii. (1880}, together with many sections of the Sables Moyens 

 of the Paris Basin. 



