606 MESSRS. GAEDJS^EE, E:EEPING, ANB MOKCKTOK ON THE 



textilis, T. plagia, &c. abound with their original colouring dis- 

 tinctly preserved, together with Solen ohliquus, Mactra compressa, 

 Cardium porulosum^ a few broken univalves, and Belemnosepia. 

 Lastly, we have the Nummulites-variolarius bed. At Stubbington 

 Mr. Fisher was able to trace the beds upward for another 30 feet, 

 and at Huntingbridge still further up*. The Huntingbridge faunat 

 is truly transitional J, but contains among many Barton forms 

 Pseudoliva ovalis, Voluta lahrella, Fusus JShce, and Cassidaria coro- 

 7iata, with a few others distinctive of the Upper Bracklesham Beds. 

 A section through much of the overlying Barton Beds could probably 

 be obtained by excavating in this vicinity. 



The Babton" Series ii?- the London Area. 



The Barton, or Upper Bagshot Series, in Hampshire, is separated 

 from that in the London basin by an interval of no less than about 

 60 miles. We are of opinion that this break is due to Post-Eocene 

 denudation, and see no reason to doubt that they once formed a 

 practically continuous deposit. 



The exact correlation of the sands, or very slightly clayey beds, 

 which alone represent the clayey series of Hampshire in the London 

 basin, is more difficult to determine ; but the fauna precludes the 

 idea that the sands of the latter at all correspond to the sandy beds 

 of the Upper Barton of Hampshire. The application of the term 

 Upper Bagshot to them, if implying an^-thing newer than and 

 distinct from the Bartons, is misleading. The clayey green sand, 

 which occurs some 10 or 20 feet below the pebble-bed at their base, 

 is undoubtedly Bracklesham, and probably Lower Bracldesham, 

 for JSfummulites Icevigatus has been found with casts of other Lower 

 Bracklesham forms §. Most of the fauna is of species common 

 to Barton and Bracklesham alike ; but a few, such as Buccinum 

 candliddatum, Volvaria acutiuscida, Bulla orhiaida, and Strigilla 

 Bigaultia7ia^ are confined to the former, the first three being quite 

 peculiar to the Lower Barton. Taking the fauna as a whole, we 

 find three species, particularly Dentalium grande^ peculiar to the 

 Upper Bracklesham ; thirty-one species common to the Bracklesham 

 and the Barton ; nine species peculiar to the Barton, of which three 

 are peculiar to the Lower, and only two, Nucula similis and Stri- 

 gilla, to the Upper Barton, the former being perhaps a not very 

 reliable determination, since it might almost equally well be N. lissa. 



There may thus be room for doubt, remembering the great thick- 

 ness of these beds in Hampshire, as to whether the beds of the 

 London basin are not partly, or even mainly, of Upper Brackle- 

 sham age, but there can be none whatever as to their being Lower 

 Barton, if they are Barton at all. The bulk of the species, being 



* Quart. Journ. GeoL Soc. toI. xviii. (1862) p. 79. 

 t Discovered by Henry Keeping. 



J Mr. Fisher described the beds as possessing a Barton matrix with Brackle- 

 sham fossils ; but the latter are actually in the minority in the highest beds. 

 § See lists in Quart. Journ, Geol. Soc. vol. iii. p. 390, vol. xsxix, p. 349. 



