126 H. KEEPING AND E. ii. TAWNEY ON THE BEDS AT 



Kev. 0. Fisher said he had visited the locality "with Mr. Tawney's 

 paper and sections in manuscript, and that he agreed with the 

 authors' conclusions. He thought the error on the part of Prof. 

 Judd might have proceeded from the fact that at the JS\E. corner 

 of Headon Hill the Middle-Headon fossils were found by the 

 sea-shore ; these, however, were not truly in situ, but had been 

 brought down by a slip ; this he thought possibly the key to the erro- 

 neous interpretation. In confirmation of the view that the Colwell- 

 Bay and Headon Yenus-beds are one stratum, he had found it with 

 its fossils in Totland brick-field, near the Hotel, exactly where it 

 should occur to connect the disjoined portions. He had worked 

 personally at the Brockenhurst locality at Whitley Bidge, and had 

 identified the bed at the base of the Middle Headon in Whitecliff 

 Bay. Consequently, if the Brockenhurst bed is to be called Oligo- 

 cene, the Middle Headon can no longer be called Eocene. 



Prof. Judd said that the paper rested largely on assumptions. His 

 method of work in the field and in the museum had been made a 

 matter of assumption. He had not hastily arrived at his conclusions, 

 but for twenty years he had worked on these British beds, and for 

 twelve years had studied their continental equivalents and collec- 

 tions of fossils made from them. The series of Eocene and Oligo- 

 cene strata in "Western Europe is perfectly clear ; but when we 

 come to Britain a difficulty has always existed. This confusion was 

 removed by distinguishing the zone of C. concavum from the Broc- 

 kenhurst series. The authors' sections were supposed to support 

 those of the Survey ; he thought on examination they would not do 

 so. The mistake had really originated from using Cytherea incras- 

 sata to fix the so-called "Venus-bed" of fossil- collectors — the fact 

 being that that shell has a wide range, and there is more than one 

 "Venus-bed." In asserting that the different " Venus-beds " are 

 upon the same horizon the authors begged the whole question. This 

 autumn he again visited the island, and found that an excavation had 

 been opened by the authors in a Venus-bed in Totland Bay, but 

 in one quite different from that in Colwell Bay. Had the authors 

 searched the Headon cliff they might have found other Venus-beds. 

 The authors had confirmed his own conclusion that the Headon-Hill 

 sands do not occur in Totland Bay ; and this is fatal to their reading 

 of the section. As regards the palaeontological evidence, he thought 

 that the method of comparison of most abundant fossils was often 

 misleading, as might be shown in the case of the Cornbrash and 

 Bagstone of the Lower Oolite. The authors say that the Brocken- 

 hurst bed is not above but below the Venus-bed. Now the former is 

 the equivalent of the Tongrian beds of Belgium ; and foreign geolo- 

 gists all regard the zone of C. concavum as the top of the Bar- 

 tonian — that is, of the Eocene. Hence the result of their interpre- 

 tation of the section was to place beds with an Upper-Eocene fauna 

 above those containing a Lower-Oligocene fauna. 



Mr. Staekie Gardner said he had always thought that in the 

 particular section under discussion there was only one Venus-bed : 

 the section of Headon Hill till last year had been fairly clear ; and 



