FOSSILS OP NORTH BUCKS AND ADJACENT COUNTIES. 481 



the deposition of the Boulder clay around the flanks of the hills— to 

 an elevation in Cumberland of about 1000 feet — the land was elevated, 

 and glaciers again descended the valleys and "ploughed out the 

 drift." It is only on such a supposition, as deduced by Professor 

 Ramsay from his observations in North Wales, that we can account 

 for the existence of old moraines at levels so far below that attained 

 by the Boulder clay. 



I remain, dear Sir, yours faithfully, 



Edward Hull. 



FOSSILS OF NORTH BUCKS AND THE ADJACENT 



COUNTIES. 



By J. H. Macalistek. 



As the geographical distribution of fossils is always an interesting 

 subject, it has occurred to me that a few words on the Oolitic fossils 

 of this part of England, not much visited by geologists, may be 

 acceptable to, at least, some of the readers of the " Geologist." It 

 will not be my intention in this paper to treat so much of the 

 geological features of the country, as to give complete lists of the 

 organic remains which have been found by myself and a few others 

 in the various strata of this district. The Oolites of North Bucks 

 and Northampton, though of course presenting, for the most part, 

 the usual character of the system as represented in other Oolitic 

 districts of England (being, as they doubtless are, merely a continua- 

 tion of those of Oxfordshire, &c), yet possess several points of interest 

 peculiar to themselves. The identity of the " Northampton Sands" 

 (formerly classed with the Lias)* with the Stonesfield Slate of 

 Oxfordshire and Gloucestershire, and constituting the Lower Zone 

 of the Great Oolite, the importance of these " sands" as an iron ore ; 

 the occurrence of land-plants similar to the Stonesfield specimens in 

 the Forest-marble of the neighbourhood of Wolverton ; the extensive 

 development of the Kimmeridge Clay at Hartwell ; and of the Great 

 Oolite further north ; — all these facts combine to invest these beds 

 with much interest, both to the geologist and the paleontologist. 



The strata which I am about briefly to describe, and whose organic 

 remains I shall enumerate, are the following 



upper oolites. middle oolites. 



Portland rock. Oxford clay. 



Kimmeridge clay. 



* So classed by Dr. Wright, being separated by him from the Inferior Oolite, 

 which they formerly were supposed to i-epresent. 



VOL. IV. 3 G 



