372 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 26, 



Position of the London Clay in the Hampshire Tertiaries. 



The question of tlie relative age of the London clay and the Hamp- 

 shire series depends materially upon the evidence afforded at Newn- 

 ham. Old Basing and Cuffell. If the London clay embraces in its 

 synchronism the Bracklesham and Barton beds, then ought we to 

 find some evidence of this expansion as it ranges westward and south- 

 westward, in the gradual preponderance of forms peculiar to these 

 latter beds. If, on the contrary, the equivalent of the London clay 

 is, as I believe, restricted to the lower fossiliferous clays of the Hamp- 

 shire system, then ought we to find at Newnham and Cuffell a fauna 

 equally related to that of these lower clays and to that of Highgate, 

 and distinct from that of the deposits of Bracklesham and Barton * . 



Notwithstanding, however, the intermediate geographical position, 

 and the favourable stratigraphical place, high in the series of the 

 London clay, of the Newnham and Cuffell beds, the following table 

 will show that the proportion of Bracklesham and Barton species is no 

 greater there than in the London clay at Hampstead and Highgate 

 {ante, p. 365). It will also appear that the strata at Cuffell and 

 Newnham contain a fauna very closely allied to that of the London 

 clay of the neighbourhood of London ; whilst it is evident that the 

 species which occur in the Bognor beds in Hampshire bear an equally 

 near relation to those of Newnham and Cuffell as well as to those of 

 Highgate and Hampstead, and exhibit no greater number than do 

 the latter of Bracklesham and Barton forms. In fact, the relative 

 proportion to the species of these latter two localities is maintained 

 in each with much uniformity. 



ward to Pebble Hill, the range of these clays cannot be so easily followed. The 

 Reading line of railway gives some good sections; and at various points from 

 thence to near Hungerford, the lower beds can be detected at intervals by their 

 organic remains, leaving but little doubt that they are all members of the same 

 series as at Newnham, as the fauna is the same throughout. 



* At first sight this seemed to be more doubtful, some forms appearing which 

 have hitherto been confined to Bracklesham and Barton, such as the Globulus 

 depressus, Fusus bulbiformis, Psammobia compressa, and Pseudoliva obtusa. Two 

 or three of these have however been found in the Bognor beds of Hampshire (see 

 Lists). The Newnham group of fossils being also from beds rather high in the 

 London clay, may possibly yield a larger proportion of fossils belonging to the over- 

 lying series than we find at Clarendon Hill, or even Cuffell, which occupy, I think, a 

 lower position. In the list of fossils at the end of this paper it is the object to 

 show that the three divisions of London, Bracklesham and Barton possess each, as 

 groups, a distinct fauna, and therefore each group is taken as a whole, irrespective 

 of subdivisions ; and the distribution in the several divisions of the respective 

 faunas, according to vertical range or to locality, is a question only casually touched 

 upon. They are all however, the London clay especially, capable of zoological 

 subdivisions. The London clay exhibits a typical group at the bottom of the 

 series : in ascending several new species appear. Then again, many of the early 

 species reappear in considerable numbers at the top of the series. But this is a 

 wide field, on which I do not purpose here to enter, as it may form part of a 

 fuller investigation into, and detail of, the Tertiary Geology of London, For our 

 present object it suffices to consider the London clay as a whole. 



