TRANSACTIONS OF SECTION C. 527 



Mr. A. II. S. Lucas, M.A., in his concise tut valuable paper ' On the Headon 

 Beds of the Western Extremity of the Isle of Wight,' ■ correctly states, upon refer- 

 ring to the recent ' answer to the present questioning of the hitherto accepted cor- 

 relations of the beds of the Lower fluvio-marine Tertiaries of the Isle of Wight and 

 South Hants, that it is obviously impossible for foreign geologists to institute 

 useful comparisons between British and foreign subdivisions so long as we in 

 England are quite at variance on the stratigraphical and palseontological facts of 

 the beds in question. - 



' The general relation of the whole group can only be satisfactorily determined 

 after the primary question of the continuity or discontinuity of theColwell Bay 

 and Headon Hill beds is settled. At present there are two very definite, yet difterent 

 views, having a perfectly distinct issue ; first, that the brackish-marine beds of Col- 

 well Bay correspond with the brackish-marine beds of Headon Hill which have 

 been seen ; or, secondly, that they correspond to some higher marine beds which 

 have not been seen.' Both these views and arguments are now fairly before those 

 competent to judge. In 1880, however, Professor Judd, in his paper 'On the 

 Oligocene Strata of the Hampshire Basin,' ^ questioned and denied the succession as 

 determined by Forbes and the Survey; this paper dealt with strata or higher marine 

 beds stated above by Mr. Lucas as ' not having been seen.' Ou the other hand, in 

 1881, Messrs. Tawney and Keeping brought to bear upon the question a mass of 

 evidence in support of the work of Edward Forbes and the Survey* showing con- 

 clusively the identity and continuity of the Colwell Bay and Headon Hill Suvio- 

 marine beds. Still more recently, however, Professor Blake ^ has 'advanced an 

 entirely new correlation, adducing stratigraphical e^sidence in its favour.' His 

 observations do not agree in certain cases either with those of Professor Judd or 

 Messrs. Tawney and Keeping. It is hoped, however, by or through evidence at the 

 present meeting, that the question of the succession will be finally determined. 

 Mr. Lucas does not attempt any solution as to the relation of these beds at Colwell 

 Bay and Headon Hill to the deposits exposed at Hordwell, Brockenhurst, or 

 WhiteclifF Bay ; they do not concern the succession. But the standard or syn- 

 thetic sections at different localities, like those prepared by Messrs. Tawnev and 

 Keeping, have tended to clear iip the succession, fully testing the continuity of 

 the beds under dispute under their several aspects along the plane of deposition. 

 This independent mode fully bears out the exact work of the Survey, showino- 

 differences in degree as regards accumulation, yet continuity as regards succession. 

 Mr. Lucas gives measured sections of the freshwater beds, and the brackish marine 

 series (p. U'J loc. cit.), which confirm the work of the above authors. 



The Headon beds were long ago ' measured by Dr. Wright, lately by the authors 

 just quoted, and the Osborne series by Edward Forbes, and the main divisions 

 are so conspicuous that there can be no doubt about the succession.' A third 

 paper upon the Fluvio-marine Beds of the Isle of Wight was read before the 

 Geologists' Association, in June 1881, under the title, ' On a Continuous Section of 

 Oligocene Strata from Colwell Bay to Headon Hill,' <= by Prof. J. F, Blake, M.A.. 

 r.G.S. The author contends for a difference between the faunfe of the Colwell Bav 

 beds and those of Hesdon Hill, and states that the ' fauna of the so-called Oligocene 

 group is chiefiy to be found in the '_' Venus bed " of Colwell Bay ; but the assumed 

 other " Venus bed " at Headon Hill contains rather the fauna of the uppermost 

 Eocene, or zone of CeritMum concavum.' The question,'however, turns upon the 

 identity of the two so-called Venus beds. In other words, the Colwell Bav ' Venus 

 bed ' is said by the author to have one fauna, and the Headon Hill ' Venus bed ' 



' Geological Mfrr/azine, n.s. decade ii. vol. is. p. 07. 



2 A concise and important paper on ' The C'lassitication of the Tertiary Deposits,' 

 by Professor Judd, appeared in the Popuhir Science llcrieiv for 1880, accompanied 

 by a table showing the correlation of the Lower Tertiary strata of AVestern Europe. 

 The Headon and Brockenhurst beds are placed under the Lower Oligocene, and the 

 Bembridge and Hempstead series under the Middle Oligocene. 



' Qvartcrhj Jovrval of the Genhgical Society, vol. xxxvi. p. 1.37 etc. 



♦ IMd. vol. xxxvii. p. 85. • Pr-iceedingg of the Geological Association, vol. vii. 



• Jhid. vol. vii. 



