1847.] PRESTWICH ON THE BAGSHOT SANDS. 391 



and Hampshire, and bat two or perhaps three are found in the 

 Barton clays. 



If we turn to the fishes, we shall find the same coincidence as in 

 the Testacea. The fossil ichthyology of Bracklesham has not yet 

 received the same attention as that of Sheppey. We believe, how- 

 ever, the number of species* found in the Bracklesham beds to be 

 far less than in the clays of Sheppey, although the individuals are 

 frequently numerous. Singularly enough (considering the rarity of 

 its fossils), we have in this instance to reason from Bagshot to 

 Bracklesham, for it is in the curious group found by Dr. Bucklandf 

 at Goldsworthy that we obtain some of our best analogues for 

 Bracklesham. It will be observed that most of the species can be 

 recognized in specimens from Bracklesham. 



Out of eight determinable species, three have a wide range in the 

 Eocene series, and are found in equal abundance in strata above and 

 below it. The other five are forms characteristic of the Brackle- 

 sham Bay series. The fine large serrated teeth of the Car char odorii 

 the peculiar long, flat, shapeless teeth of the Pristis, and the singular 

 palates of the Chimceroid fishes, are as a group very distinctive of 

 this period. 



At the partly-intermediate locaUty of Southampton we have already 

 seen that the geological structure of the upper strata (fig. 5, p. 388) 

 is, as far as it goes, conformable on the one hand to that of the 

 Bracklesham series at White-Cliff Bay, and on the other, to that of 

 the Bagshot sands ; and also, that the organic remains of the 300 

 feet of brown and grey clays which underlie them agree with those of 

 the London clay. 



We can now further show, that not only is the structure similar, 

 but that the organic remains of these strata overlying the London 

 clay are in perfect agreement with the Bracklesham group. In the 

 100 to 150 feet of yellow sands (stratum *'5," fig. 5, p. 388) im- 

 mediately overlying the London clay, no fossils have been found. The 

 foliated brown clays (3 of "a") succeeding these sands are not well 

 exhibited. Above them are probably the beds of hght yellow and 

 greenish calcareous and clayey sands (2 of "«"), with occasional large 

 calcareous concretions, from 1 to 6 feet in width and 1 to 2 feet in 

 depth, and full of fossils. In a pit by the side of the old canal, 1 J 

 mile W.N.W. from Southampton, several weathered blocks of these 

 concretions may be seen. 



Fossils of part of the Bracklesham beds%, near Southampton. 



Anomia lineata, Sow. Cassidaria coronata ?, Sow. 



Bulla, n. s. (the common Bracklesham Corbula globosa, Sow. 



one). rugosa?, Lam. 



Cardium poralosum, Brand. — pisum ?, Sow. 



turgidum ?, Sow. striata, Lam. 



* Many genera occurring at Sheppey are wanting at Bracklesham. 



t Proceedings of the Geol. Soc. vol. ii. p. 687. 



t I apply the term of Bracklesham beds to the strata of clays and green sands 

 forming the central division of the arenaceous series, the whole of which I desig- 

 nate as the Bracklesham sands. 



