226 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 5, 



sideration of that formation, commercially most valuable, and geo- 

 logically most interesting, the Northampton Sand. 



The main feature of my Second Part will be the description and 

 consideration of a series of beds grouped by Mr. Judd under the 

 name of the " Lincolnshire Limestone" — of less commercial value 

 than the former, it is true, but scarcely of less geological interest. 



My endeavour has been to trace, through the county in a north- 

 easterly direction, to Stamford and somewhat beyond, the continuity 

 of beds occurring in the Northampton district; to describe the 

 Oolitic beds and their sequence at certain points within the area 

 considered (involving the interposition of a new and important for- 

 mation) ; to examine the geological characteristics of the districts 

 round Stamford, and very briefly those of the eastern portion of the 

 southern border of the county ; and thus, while giving a general 

 idea of the geology of the Northern Division of Northamptonshire, 

 to help to establish the soundness of certain views not yet held to 

 be altogether conclusive. 



My data were gathered and this Memoir was drafted before I 

 had the advantage of examining Mr. Judd's Geological Survey Map, 

 Sheet 64 ; while, unfortunately for geological science, but perhaps 

 as well for the object I have in view, that gentleman's Memoir has 

 not yet become the property of the public. 



It may perhaps by some be deemed superfluous in me to have 

 produced this treatise at all, seeing that Mr. Judd's map is already 

 in the hands of geologists, and that his Memoir will shortly be pub- 

 lished. 



But some geologists still hesitate to accept the dictum that the 

 beds of the Lincolnshire Limestone are Inferior Oolite ; and, as Mr. 

 Judd, after some years of close and systematic examination of those 

 beds, and I, after a less systematic and exact although longer ac- 

 quaintance with them, have independently come to the same con- 

 viction upon this point, I have thought that my second voice might 

 not be without service, nor my local information without interest — 

 especially as I have come armed from the beds to be discussed with 

 an array of significant fossils, those once animate though now 

 inanimate " oldest inhabitants," those silent yet eloquent witnesses 

 to the truth of the conclusions at which we have arrived. 



Before entering upon the task I have essayed to accomplish, as 

 the Northampton district will, as it were, form my starting-point in 

 tracing out the extension eastwards of the Oolitic beds of that 

 district, it will be well to recall to notice the General Section given 

 in my former communication. 



It will be seen by this diagram that upon the clay of the Upper 

 Lias are superimposed the series of beds of the Northampton Sand, 

 having a maximum thickness of about 80 feet ; which beds were 

 divided by me (because of certain distinguishable characteristics) 

 into " Lower," " Middle," and " Upper ;" that upon the summit of 

 the Northampton Sand occurs a plane of unconformity, indicated in 

 the diagram as the " Place of the Great Limestone of the Inferior 

 Oolite" (the Lincolnshire Limestone of Mr. Judd) ; and that above 



