Mr. De la Beche on the Geology of Part of France. 77 



and another of a bivalve, were all the organic remains that I observed in it. 

 It is first seen at Cap la Hevc dipping gently to the east: and it forms the flat 

 upon which Havre is built*. At Honfleur it may occasionally be discovered 

 amid the fallen masses of chalk and green sand ; and at Henqueville it forms 

 a bed a hundred and fifty feet thick interposed between green sand and oolite, 

 but it is not seen further to the west. 



Oolite Formation. 



I include under this head the series of rocks, which begins with the Portland 

 beds, and ends with the inferior oolite. 



Portland Beds. — At Henqueville cliff may be traced thin beds of a hard 

 yellowish-white limestone, which contain seams and nodules of chert, and casts 

 of fossil shells, the same with those which are observable in the Portland beds; 

 these rest upon coral rag. They are however much concealed by the fall of 

 the superincumbent beds ; and I was not fortunate enough to meet with them 

 in the interior. 



Coral Rag. — This rock, accompanied by calcareous grit, first appears on 

 the east of Henqueville cliff, of which it forms the lower part. Proceeding 

 westward, it forms the top of the hill between the river Toucques and Bener- 

 ville, and thins off upon the eastern part of the Vaches Noires cliffs. Near 

 Villers sur Mer it contains a vast quantity of corals and Echini. 



Oolite and Blue Clay. — The latter is first seen on the coast forming the 

 lower part of the hill between the Toucques and Benervifle. Inj this place 

 the beds of calcareous sandstone and oolite, which are to be seen between the 

 coral rag and blue clay at the next hill to the westward (the Vaches Noires 

 cliffs), are not exposed to view ; but as the summit of the hill is composed of 

 coral rag, there can be little doubt of their existence. 



The Vaches Noires cliffs afford an excellent section of these rocks. The 

 coral rag and calcareous grit thin off, as before stated, on the east : under these 

 is found a whitish marl ; then a bed of oolite about four feet thick ; then blue 

 marl or clay. This last is about three hundred feet in thickness, and agrees 

 in its geological position with the Oxford clay : it contains septaria, and a few 

 thin beds of grayish limestone ; and among its fossils are the following : — 



* At Havre the marl is used for making tiles and bricks. 



