82 riiOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 4, 



from fossil contents and sequence renders it most probable that the 

 two are equivalent, and therefore that the Shepherd's Gutter Bed is 

 equivalent also to the Niimmulina varlolaria beds of Stubbington and 

 (the "Clibs")of Selsea. 



But the argument is still further strengthened thus. Let it be 

 granted that the Shepherd's Gutter Bed is equivalent to No. xvii. 

 of White Cliff Bay ; it is therefore equivalent to the Nummulina 

 variolaria bed of Stubbington. Now, there is at Stubbington, about 

 thirty feet higher up, a very remarkable bed, No. 20, containing 

 Paracyathus caryojphyllus and Dentalia ; whilst a bed with similar 

 contents is also found in the New Forest, at Hunting Bridge, 

 not many feet above the ShexAerd's Gutter Bed. It mU. be seen 

 that the above contains also the data upon which I have ventuied to 

 dijffer from former observers* respecting the line of separation 

 between the Bracklesham and Barton Beds at White Cliff Bay, and 

 to place it slightly higher up. 



At about a mile and a quarter S. by W. of Shepherd's Gutter, 

 near the letter " Z; " in " Brook Common " on the Ordnance Map, at 

 the corner of Prior's Acre, is a fossil-bed, in its leading features 

 very similar to that at Shepherd's Gutter. The stratum coveriiig 

 the fossil-bed is soft blue clay. To this succeeds a bed of clay 

 crowded with Turritella imbricataria and T. carinifera, and then a 

 bed of dark sand with many shells. This last is not so thick as at 

 Shepherd's Gutter, averaging about 1| foot. There are not so 

 many broken shells ; but the percentage of tolerably perfect shells is 

 perhaps larger. Beneath it we find decayed Pectines cornei in a 

 sandy clay. Oardita planicosta is very rare. This bed is, I believe, 

 a continuation of the Shepherd's Gutter Bed, and is on the horizon 



of XVII. 



A section, by digging and boring, gave — f|. j^ 



Superficial soil 2 



Soft, weathered, blue clay, with selenite t and Turritellce 7 



Fossil-bed (6) 1 



Stiff slate-coloured clay 3 6 



A thin fossil -bed, with Pec^fiTz corwews J say 3 



PurpUsh, very sandy clay (not pierced), probably c of Bracldesham 2 



BrooTc. — About a quarter of a mile down the brook or '* gutter " 

 called King's Garden Gutter, in which the last-mentioned bed was 

 reached, occurs a second rich fossil-bed, which lies beneath it. It 

 is that cited by Mr. Edwards § as the " Brook " locahty. After 

 passing through a covering of clay, a thin bed of dark-green sand 



* Prestwich on Bagshot Sands, Quart. Journ. Geol. Soc. vol. iii. p. 388. 



t A collector should keep a look-out for selenite, because it is often the 

 only indication, seen on the surface, of the neighbourhood of fossil shells. When 

 clay contains fossil shells and sulphuret of iron, the change which takes place in 

 the course of weathering is this : — The sulphur combines with the oxygen 

 of the atmosphere to form sulphuric acid ; this combines slowly, as it is formed, 

 with the carbonate of lime of the shells, and crystallizes into selenite, the shell 

 being ultimately entirely removed. 



X Corresponding probably with the thin fossil-bed, containing Pecten corneus, 

 mentioned as occurring at Shepherd's Gutter. 



§ Pala;ontographical Society's Monographs, 1858, p. 270. 



