1822.] Geological Society. 231 



whicli he had before remarked some traces in the Oxfordshire 

 specimens. 



In the cut made for a new road to ascend CHfton Downs fronoi 

 the Hot Wells, Mr. C. met with a specimen of one of those 

 stones which have been generally referred to the Cactus tribe ; 

 and in which a part of one of the supposed species or leaflets 

 was in situ, but broken off* about a quarter of an inch from the 

 base of the depressed pustule, with which, however, it exactly 

 fits. 



Among the specimens of echinus in Mr. Cumberland's collec- 

 tion are two species, viz. the esculentus, and the cordiform, both 

 of which exhibit opercula in situ, and another in which the inte- 

 rior with a cell to receive it when withdrawn, is manifest. 



Dec. 7. — The reading of M. de la Beche's *' Observations oa 

 the Geology of the Coast of France," was concluded. 



From Fecamp to Cap d'Antifer, the chfFs are composed of 

 chalk with flints, containing the usual fossils of the same chalk 

 in England. From the latter point, similar strata resting on. 

 green sand extend to beyond the Chateau d'Orchet, when the 

 sand disappears. That portion of the interior which is bounded 

 by the coasts of the sea and Seine, consists of chalk covered 

 generally by flint gravel. 



The green sand forms the under part of the cliff* as far a& 

 Cauville, where it appears to rest in marl containing green, 

 earth. At Cap de la Heve, an inferior bed of iron sand, con- 

 taining mica and sihcious grains, and overlying blue marl, and 

 marl stone, becomes visible. This green sand contains abun- 

 dance of alcyonia, echinites, and other organic remains. 



At Benerville, the green sand is wanting, but the Vaches 

 Noires Cliffs between Villers sur Mer and Dives are capped by 

 it; and it there rests partly upon coral rag, and partly upon 

 oolite beds above a thick blue clay, corresponding in character 

 with the Oxford clay, and contains a variety of organic remains, 

 among which are some remarkable alcyonia that have been 

 described and figured by M. Lamouroux. Inland, the prevailing 

 rock, is a loose silicious sand, containing nodules of blue lime- 

 stone, or chert, dispersed in layers. Near Lisieux, a thick 

 stratum of whitish soft calcareous sandstone, containing green 

 earth, is quarried under it for the purposes of building. 



The blue marl and marlstone which rises under the iron sand 

 at Cap de la Heve is composed of marl and argillaceous limestone 

 in alternate layers, and has so much the appearance of blue lias 

 that it has been mistaken for it ; but an examination of Hengue- 

 ville Chff' shows it to rest on the oolite formation. At the latter 

 place, it is about 150 feet thick. This stratum contains the 

 fossil crocodiles mentioned as found at Havre, and described by 

 M. Cuvier. 



Some traces of Portland beds are observable above the cora! 

 lag at Hengueville cliff*. The latter contains numerous fossil 



