524 KEPORT— 1882. 



and a freshwater (?) in addition to those which have heen universally accepted for 

 the last twenty-five years.* 



The sections prepared by Professor Judd also differ very considerably from that 

 of the Geological Survey, or those lately prepared by Messrs. Keeping and Tawney, 

 durijg their late examination of the beds under notice. These are the marine series 

 known as the Middle Headon or Middle Marine. Prof. Judd places them at the sea- 

 level near Widdick Chine. Consequently, between the top of the marine bed and 

 that of the Bembridge limestone, there would be, on Prof. Judd's theory, 250 feet 

 of beds, such being the altitude of the cottage on the Warren which marks the 

 summit of the Bembridge limestone. This thickness must, however, be reduced by 

 100 or 105 feet, which is the altitude of the top of the Middle Headon at this point. 

 This 105 feet of beds, or anothe?- freshwater and another marine, have no exist- 

 ence ; they can only be accounted for by counting the Lower and Middle Headon 

 twice over. Now the only marine beds are those of the Middle Headon, enclosed 

 between the altitudes of 70 feet above the sea-level ; the others are all freshwater. 



The point wherein Professor Judd's section differs from the Survey and 

 that of the authors, arises from the belief that a second marine series, termed the 

 * Brockenhurst series,' with another freshwater below, in all 105 feet, is intercalated 

 above the Upper Ileadon — these two beUeved 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. It must be remembered that there is no positive 

 evidence of the existence of this second marine {Brockenhurst) series at the spot 

 where the Geological Survey places the Osborne marls. Careful examination fails 

 to reveal these said-to-be additional beds. It is clear, therefore, that no bed having 

 the peculiar fauna of the Brockenhurst bed occurs at the west end of the island ; its 

 place too, if found, would be at the base of the Middle Headon and not above the 

 Upper, where it has been wrongly assigned. Messrs. Keeping and Tawney, in their 

 paper, object to the correlation of the Brockenhurst with the Colwell Bay bed — 

 which is identical with the marine (Middle Headon) bed of Ileadon Hill. Thus the 

 105 feet of strata have no existence. 



The Middle Headon, which is denuded away from the top of the cliffs in the 

 centre of Totland Bay between Weston and Widdick Chines, has been discovered 

 in the Totland Bay brickyard, which lies a little inland of this portion of the cliff, 

 thus conclusively showing that this bed was continuous above the top of the cliff, 

 consequently linking the Warden Cliff exposure to that of Headon Hill. They are 

 visibly and absolutely continuous with those of Colwell Bay. 



Falceontological Evidence. — The equivalency of the Colwell Bay and Brocken- 

 hurst beds is a point to be definitely settled. Most careful lists of fossils have been 

 prepared from collections made both from the Middle Ileadon at Colwell Bay and 

 Headon Hill. We find that out of fifty-seven species at Colwell Bay, fifty-three 

 occiu- in the Middle Marine of Headon Hill, or 93 per cent. This clearly proves 

 the identity of the horizon in the two localities. 



The well-known shells Cerithium concavum and C. ventricosxim occur both in 

 Colwell Bay and Ileadon Hill, and on the same horizons. C. concavum appears 

 to have a less restricted range at Headon Hill than C. venti-icosum, occxirtmg abun- 

 dantly there through the greater part of the Middle Ileadon series. It has also 

 been found in the ' Venus bed ' of Colwell Bay. Thus both stratigraphical and 

 palffiontological evidence are in harmony. All evidence tends cleavly and con- 

 clusively to show that there is only one marine series in this section, viz. the Middle 

 Headon of Edward Forbes, which is interstratitied between the freshwater Lower 

 and freshwater Upper Headon ; while there is no evidence of the Brockenhurst 

 bed occurring anywhere in the west of the island. 



Whitecliff Bay ami the Neiv Forest. — The Brockenhurst bed was recognised at 

 Whitecliff Bay, by the Rev. 0. Fisher, in 1864, where it occurs in the lowest two 

 feet of the Middle Headon series. No less than 70 species have been collected 

 here out of 104 known at Brockenhurst. Many species are peculiar to it, but all 

 are identical with those of the well-known section in the railway-cutting near 



• Quarterly Journal of the Geological Society, vol. xxxvi. p. 137. 



