hibited in the cliflf. He stated that he had not particularly 

 studied the London clay deposits, but that he borrowed his 

 descriptions from the admirable paper of P. Prestwich's, 

 in the Geological Journal. On descending the cliffe 

 at Eeculver we found it j composed of an argilacious 

 sand, having large tabulated blocks of some indurated por- 

 tions of sand stone, projecting at the base of the cliff, and 

 under these were found large quantities of brittle bivalve 

 fossil shells — this is called the Thanet Sands. Passing 

 along towards Heme Bay this strata gradually dips to the 

 N. "West, and at a point called Bishop Stone, or 

 Old Haven Gap, two miles east of Heme Bay, the follow- 

 ing section is met with: — 1. Brown and yellow clay 

 mixed with ochrous flint gravel. 2. London clay in 

 beds of brown colour, containing numulites. 3. Thin 

 irregular bed of green ferruginous clay with round 

 black pebbles, 2 to 3 inch. 4. Very light yellow 

 sands with ^tabular concreted masses of sandstone, 

 underlaid by a mass of dark clay with very friable shells, are 

 dispersed in patches. 5. Small flint pebbles with a very 

 irregular series of ferruginous sandstone, full of casts of 

 shells. Jlr. Mackeson explained that we were in the 

 London clay formation, called the eocene, which overlaid 

 the chalk or cretaceous beds, and which formed a large 

 basin, and it is supposed that the Paris, London, and 

 Hampshire beds, formed originally one vast bed of a gulph 

 (the shells contained in them partaking more or less of the 

 character of shells found in such marine situations), and 

 that the London bed had been separated from the 

 others, by the up-heaving of the chalk which now 

 intervenes. One characteristic of the^^London clay 

 fossils is that of containing tropical fruits ; the 

 particular appearance of these in certain situations favours 

 the belief that they were tben deposited by some estuary. 

 (The number; of ( tjl^^ef&Tts found in these deposits 

 exceeds one thousand). The London and Paris basins differ 

 principally iu the latter contaiuiug limestoue, which is 



