282 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Feb. 5, 



I. That the Upper Estuarine Series of Sands and Clays (subject 



to local denudation) ranges over the whole of the wide reach 

 of country" described, and is everywhere immediately sub- 

 jacent to the Limestone beds of the Great Oolite, when these 

 are present. 



II. That the Lower Estuarine Series has an equally wide spread, 



and as persistently overlies the more or less Ferruginous beds 

 of the Northampton Sand. 



III. That, throughout the wide range of the Lincolnshire Lime- 

 stone, the place of that Limestone is immediately below the 

 Upper Estuarine Series (where not denuded), and imme- 

 diately above the Lower Estuarine Series. 



IV. That, therefore, necessarily, the Limestone of Kingsthorpe 

 and other high localities about Northampton, and the ex- 

 tensive Limestone now known as the Lincolnshire Limestone, 

 are distinct, and belong to different geological periods. 



The palceontological evidence also necessitates the last Proposition, 

 and determines further the geological period to which each of these 

 distinct formations belongs — and this, not upon the presence of one 

 or a few fossils only, but upon the general fades which the organic 

 contents of these formations severally present : — 



I. Organic forms obtained from the Limestone overlying the Upper 



Estuarine Series in the neighbourhood of Northampton are as 

 a group so identical with those obtained from beds in the 

 same position in the neighbourhood of Stamford, that, if a 

 number of , fossils from one locality were asserted to have 

 come from the other locality, and vice versa, the assertion 

 could not be disputed on palseontological grounds ; and the 

 general character of these forms would indicate that they, 

 and therefore the beds in which they occur, belong to the 

 Great-Oolite period. 



II. The organic forms obtained from the Lincolnshire Limestone 



comprise an altogether different group. Few of them are 

 identical with fossils of the Great Oolite Limestone, while 

 many are identical with fossils which occur in the Ferru- 

 ginous beds of the Northampton Sand ; and their general 

 character indicates that they, and therefore the Lincolnshire 

 Limestone, are of the period of the Inferior Oolite. 

 These Propositions proven, I contend that Physical Geology and 

 Palseontological Geology combine to afford indisputable evidence of 

 the truth of the conclusions which I pre-stated in my Introduction. 

 Therefore — the General Section of the north-eastern portion of the 

 Northern Division of Northamptonshire, will be represented in the 

 Diagram I., which includes the Lincolnshire Limestone ; while the 

 General Section of the south-western portion of that Division, will be 

 represented in the Diagram II., which excludes that formation*. 



* See fig. 4 — opposite page. 



