528 RKPOBT— 1882. 



another. This determination I hold to he untenable, all fossil and physical evidence 

 being to the contrary, and show that they are one and the same bed. On both sides 

 of Bramble Chine the ' Venus bed ' is fully developed. Mr. Blake calls it the 

 ' Oyster bed.' Below these come thin bands of stratified marl, with abundance of 

 Cerithea and Cyrena (not Cyclas, as stated). The Widdick Chine sands can be no 

 other than the Ileadon Hill sands, and not the Upper Bagshots. The altitude of 

 these sands above the sea Mr. Blake estimated at 100 feet ; this is certainlv 

 too great an elevation, 70 feet being the received measurement by independent 

 observers. Such difference, if it existed, would alter the reading and sequence of 

 succeeding and higher beds in the section. The author seems to have omitted 

 the Trigonorcelin and NeritinaheA. immediately above the How Ledge limestone and 

 below the thick oyster band. These correspond with the Warden Cliff section, and 

 determine continuity of deposition, or are a confirmation of the identity of the beds. 

 This is a crucial point in the continuity and equivalency of the marine series in 

 Totland and Colwell Bays. The Trigonocoelia bed here is on the same horizon 

 as in Warden Cliff and Colwell Bay, associated with Cerithium pseudoctncttmi, 

 Melanopsis fusiformis, Natica labeUafa, &c. The lower or Neritina concava 

 bed, with Melanopsis fusiformis and Coj-hicula ovata, occurs also in tlie same 

 position near the base of the series at Warden Cliff and Colwell Bay. ' This can 

 only be explained by admitting that the Marine series in Totland Bay and Colwell 

 Bay are identical.' The occurrence of ' Cerithium ventricosum at the top, and tbe 

 nei-itina \_N. concava] and Trigonoccelia \_2\ deltoidea] at the base — identical in 

 physical and fossil characters, are strong presumptive proof of this.' It is extremely 

 doubtful if Cerithium mnrynritaceiim, mentioned on page 6 of Mr. Blake's paper, 

 occurs in the Colwell Bay section, or in the western area of the Isle of Wight — 

 the Cerithium cinctum is really C. pseudocinctum, and Cijclas obovata should be 

 Cyrena obovata. The genus Cyclas does not occur. In correlation these are impor- 

 tant items, especially with a continental fauna. It will also be found that the 

 oyster beds do not rest immediately on the How Ledge limestone as asserted — the 

 Triyonocalia and Neritina beds intervene, and, as at Colwell Bay, determine or 

 prove the succession and identity of the sei-ies. At pp. 156-7 Mr. Blake remarks 

 upon the similarity of the succession of the Colwell Bay beds with those of Headon 

 Hill, and h ' tempted to come to the conclusion' that the two ' Venus beds are 

 identical ;' [they have always been so believed and recognised] : he at the same 

 time states that ' it would be absurd to argue that they are identical because they 

 contain similar common fossils,' when it has been ' determined by Professor Judd 

 that the faunas are remarkably distinct.' We have no other method whereby to 

 determine the age and synchronism of deposits except through organic remains, and 

 the faunre of the ' Venus beds ' at both localities are to me identical, and Professor 

 Blake depends upon fossil evidence all through his paper, yet evidently he 

 has not carefully examined the more complete fauna of the ' Venus bed ' at 

 both localities. In another paragraph, on page 157, the author states the 

 proposition ' that the Colwell Bay " Venus bed " is not certainly identical 

 with that at Headon Hill, but may occupy a higher horizon.' Mr. Blake sug- 

 gests that the Headon Hill bed corresponds with the series intervenin? between 

 the Colwell Bay bed and the How Ledge limestone ; and that the Colwell Bay 

 bed corresponds with the slightly fossiliferous sands immediately below the Headon 

 Hill limestone. This position or suggestion certainly cannot be received. In 

 this case the so-called two ' Venus beds ' would be superposed on each other, and 

 nothing to separate them. The sands referred to are those at the base of the 

 Upper Headon series, and are freshwater, for they contain Thiio. Again, Pro- 

 fessor Blake's suggestion would thus place the Colwell Bay ' Venus bed ' below 

 the Great Limestone, whereas Professor Judd in his paper would place it above. 



The author does not find any equivalents of the Colwell Bay oyster beds above 

 the Heidon Hill limestone at Headon Hill ; indeed that would be impossible, for 

 they are indisputably the Osborne marls of Professor Forbes, and capped by the 

 Bembridge limestone. 



As regards the terms Eocene and Oligocene, and their relation to each other, 

 and the correlation of British strata and fossils with those of Germany, &c., it is 



