518 On the Displacement of Shore-lines. 



siliceous limestone with marl and clay. This division there- 

 fore finishes a little to the left of the summit of arc 2'. 



Sables de Monceaux, beds 143-145. Marine sand with 3 

 Septaria layers. — The rest of arc 2'. 



Marnes aPholadomya, beds 146-154. Marine, with 2 alter- 

 nations of siliceous limestone and marl. — The first part of 

 arc 3'. 



Gypsum No. 3, beds 155-158. Marine marl and gypsum, 

 1 alternation, and 



Marnea Lncina, bed 159. — The rest of arc 3'. 



(The beds 146-159 thus have together 3 alternations 

 and correspond to the arc 3'.) 



Gypsum No. 2, beds 160-196, arc 4'. — Marine, at any rate 

 for a great part. But it must be remarked that no fossils 

 have been cited from the last part of this series. Gypsum 

 alternating with marls about 5 times. The most important 

 gypsiferous horizons are the beds 161, 171-176, 178-188, 

 191 and 194. 



Gypsum No. 1, bod 197, 8 metres thick, with freshwater 

 animals. 1 alternation. — Between arcs 4' and 5'. 



Marne hleue, beds 198-204, and Marne blanche, beds 205- 

 209, freshwater marls alternating with marly limestones and 

 fen-uginous marls about 4 or 5 times. — Arc 5' and the first 

 third of arc 6'. 



Marne verte, beds 210-217, a brackish-water formation 

 with 2 alternations of clay with marl and siliceous limestone. 

 — The upper part of arc 6'. 



Calcaire de Brie, beds 218-220, a freshwater limestone. 

 Perhaps we have here indications of several climatic alterna- 

 tions, for limestones occur alternating with marl 3 or 4 times, 

 though certainly in very thin beds. — Its place is in the hollow 

 between arcs 6' and 7'. 



Marne et Mollasse Marine, beds 221—231. Clay alternating 

 with marly limestone and sandstone 3 or 4 times. — The 

 upper part of arc 1'. 



Sables de Fontenaye, bed 232. Marine sand with a few 

 layers of clay, but without marked alternations. — The latter 

 part of arc 1' . 



Calcaire de Beauce (p. p.). — Freshwater, between arcs 

 V and 8'. 



From this we get a complete agreement with the palseonto- 

 logical results, as shown by the following comparison of the 

 equivalent formations in both basins : — 



