OF THE PARIS BASIN. 9 



visit there last year, we found the pit half-filled with water, but 

 the strata were sutificiently exposed to give us a typical repre- 

 sentation of the unctuous black or blue-black clay with fossils. 

 Of tlie latter, amongst others, we brought away Corbicula lUtiei- 

 foriiiis, Melania inquinata^ Neritina globulus, N. consobrina, 

 Potamides funatus, P. turbinoides and Tritonidea lata. 



The Lignites, which are never more than thirteen feet in thickness, 

 are here and there worked for copperas and alum. A lacustrine 

 marly and bituminous limestone is sometimes found in the upper 

 part of the formation ; along this horizon also, at Molinchart, 

 we get a sandstone quite fifty-eight feet in thickness. The Belleu 

 Sandstone, near Soissons, celebrated for its plant remains, is 

 probably of the same age. The flora has been described by M. 

 Watelet,* and others, and includes Ctnnamonmm formosum, Salix 

 axcnensis and Ficus. 



Near Rheims the " Conglomerate of Cernay," from eighteen 

 inches to twenty-three feet in thickness, and the " Marl of 

 Cernay," from three feet to thirty-two feet in thickness, have 

 been rendered famous by the extremely interesting and well- 

 known mammalian fauna, described by M. Lemoine. The 

 Marl is also found at Mont de Brimont, Rilly, Mont de Berru, 

 Vandeuil and other localities. Above it come thirty-six feet of 

 lignites and clays with pebbles, in which the fauna is practically 

 the same as that at Sarron already alluded to. 



The Lignites and associated clays are also well developed near 

 Epernay. In the vicinity of Montereau the Plastic Clay is 

 employed in the manufacture of porcelain ; and in that district 

 also is found the " Conglomerate of Nemours." 



8. SANDS OF SINCENY. 



These sands, as the name implies, are typically developed at Since- 

 ny, near Chauny, on the left bank of the Oise. In early days they 

 attracted the attention of MM. d'Archiacf, Hebert:J:, and Lam- 

 bert §. More recently the precise relationships subsisting between 

 them and the beds above and below have been very carefully 

 worked out by MM. De Mercey || and G. Dollfus^. The sands 

 of Sinceny clearly form a transition between the Lignites and the 

 Nummulitic sands of the Soissonnais. The principal section, 

 near Sinceny, is thus given by the last mentioned authority. 



* Watelet, Desc. des plantes/oss. du Bas. dc Paris, Paris, i366. 

 tD'Archiac, Desc. Geol. du Dept. dc t Aisne, p. 165. 



X Hebert, Bull. Soc. Gcol. Fr., ze. s^r., t. xi. (1854), p. 655 ; and ae. sdr., t. xviii (i860), 

 P- 77- 



§ Lambert, &tud. Geol. sur le Terr. Tert. au nord de Paris, Soissons, Laon (1858). 

 II De Mercey, Bull. Soc. Geol. Fr., 36. ser., t. vi. (1878), p. 200 ; vii. (1879), p. 579. 

 T[ Dollfus, " Lcs Sables dc .Sincoiy." Ann. Soc. Gcol. du Nord, t. v. (1877), p. 5. 



