ine dy Sa ea ES 
Phosphatic Deposit at Potton, in Bedfordshire. 119 
and in-places these deposits almost stand on end, through false 
bedding. They are seven feet thick, and unfossiliferous, a good 
deal resembling the beds below; but I cannot say they should 
not be classed with the Gault. A rolled fragment or two of 
Ammonites biplex is the only fossil I have found in the rock ; so 
that it might be Portland Sands but that it is traced to Hunstan- 
ton, where fossils are more numerous.” Mr. Seeley then pro- 
ceeds to trace the bed to near Potton and Sandy. He evidently 
at the time he published the above (December 1865) considered 
the bed to be of the same age as I do, but has since altered his 
opinion. [I shall again have occasion to refer to the second 
paragraph quoted above. I am not aware that Neithea quinque- 
costata has ever been found in the Kimmeridge Clay at Wey-. 
mouth or elsewhere. 
II. Mr. Seeley says, “ The term conglomerate applied to 
this bed is calculated to mislead,” and gives a definition of what 
he thinks a conglomerate ought to be. In the paragraph already 
quoted Mr. Seeley applied this term to the same beds! I wished 
to involve the idea he objects to, viz. the denudation of older beds. 
III. I stated that, if Mr. Seeley’s views be correct, the term 
Carstone is inapplicable to the bed. On the idea that the Car- 
stone at Hunstanton represents the Gault and Lower Greensand, 
he forms his remarkable hypothesis of the Significance of the 
Sequence of Rocks*. He now-restricts the term to the sands 
of Yorkshire, Lincolnshire, and Norfolk, between the Hunstan- 
ton Limestone and the Kimmeridge Clay, and says, “ But though 
I abandon the term, I do not abandon the idea,” which idea he 
proceeds to illustrate by a diagram, but does not attempt to 
prove it; therefore I will not discuss the merits of it. 
IV. I appear to have misunderstood Mr. Seeley’s remarkable 
expression “the truth is, the ‘Sandy nodule bed,’ as this bed in 
the Carstone may be called, reproduces earlier in time the con- 
ditions of the Cambridge Greensand.” I am very sorry; but it 
may be due to the ambiguity of the sentence tending to mislead. 
- But I am still of opinion that two deposits so different in every 
respect as the Cambridge Greensand and the sandy conglomerate 
bed at Potton and elsewhere cannot have been accumulated 
under similar conditions. Mr. Seeley by no means explains the 
discrepancies between the two formations indicated in my former 
papery+, nor does he bring forward a particle of evidence in 
support of his assumption that both were formed upon a long 
low shore. . 
_ V. Mr. Seeley ascribes to me the “notable discovery that by 
soaking six or seven parts of alumina in decomposing animal 
* Geological Magazine, vol. ii. pp. 262-265. 
+ Ann. Nat. Hist. ser. 3. vol. xviii. p. 383. 
