GO Mr Tawney and Mr Keeping, On the beds of [Dec. G, 



section where they are represented, they can only have been ob- 

 tained by counting the Lower and Middle Headon twice over. 



The proof of the correctness of the description by the Survey 

 of the beds at this point in opposition to the views of Prof. Judd 

 has been worked out by a fresh measurement in detail in a 

 vertical direction of all the strata between the Bembridge lime- 

 stone and the sea-level. The strata were measured bed by bed, 

 the fossils in each being noted, so that the limits of the freshwater 

 and marine might be determined, and the various members be 

 recognized by the distribution of fossils as well as by lithological 

 characters. 



The beds at this point with their thickness are in abstract as 

 follows — in descending order : — ■ 



Bembridge limestone 25 feet, 



Osborne Marls 70 feet, 



Upper Headon 51 feet, 



Middle „ (marine) 33 feet, 



Lower „ to sea-level 71 feet. 



The only marine beds are those of the Middle Headon, enclosed 

 between the altitudes of 70 feet and 105 feet above sea-level ; the 

 remainder are all freshwater. The description of these and their 

 gross thickness agrees fairly well with the vertical sections of the 

 Geological Survey, and is held to be corroborative of their results. 



The point then in which Prof. Judd's section differs from the 

 above, lies in this, that a second marine series which he terms 

 " Brockenhurst series" with another freshwater below it, in all 

 105 feet, is intercalated above the Upper Headon, these new 

 formations having that portion of the section allotted to them 

 which is occupied by the freshwater Osborne Marls, and part of 

 the Upper Headon in the above section. No positive evidence 

 is adduced by Prof. Judd of the existence of this second marine 

 series at the spot where the Survey place the Osborne Marls ; it is 

 apparently supposed to be concealed by gravel and landslips. The 

 authors have however examined the ground, and they find no 

 gravel or concealment of beds at the place indicated, but recognize 

 there the red and greenish mottled Osborne Marls, precisely as 

 laid down in the vertical sections of the Survey. They therefore 

 hold that no second marine series of any kind exists at this spot, 

 much less any bed having the peculiar fauua of the Brockenhurst 

 bed, which does not occur at all at the west end of the island ; 

 moreover, if it did, it would be found at the base of the Middle 

 Headon, and not above the Upper Headon, where it is supposed 

 to be by Prof. Judd. The authors object therefore to the cor- 





