Additional note. 



A mistake has been made above in placing the Headon 

 beds of the Isle of Wight in the Upper Eocene. The causes 

 which led to this mistake were: a certain stratigraphical 

 similarity between the Calcaire de St. Ouen and the Osborne, 

 both being fresh- water formations with the same number of alter- 

 nations; then the difficulty in deciding the true number of cli- 

 matic alternations in the fluvio-marine beds of Wight. Though 

 I was, indeed, well aware of the fact, that the fauna of the 

 Middle Headon is Oligocene, I thought it not quite impossible 

 that the Oligocene fauna might have immigrated earlier into 

 the Hampshire basin than elsewhere in Europe. But the diffe- 

 rence between the faunas of the Gres de Beauchamp and the 

 Middle Headon is far too great. These two faunas cannot pro- 

 sibly be synchronous. And it is the more superfluous to make 

 the above named supposition, because, as will be presently shown, 

 the Isle of Wight profile may be fitted into the curve of 

 eccentricity in a manner, that agrees exactly with palseontologi- 

 cal evidence. 



In the Paris Basin where sedimentation went on very slowly 

 and where chemically deposited layers are much more prominent, 

 it is less difficult to determine the number of climatic alternations. 

 fi ut it is otherwise in the Isle of Wight. In these beds many irre- 

 gularities occur; there are many lenticular intercalations, and as 

 the vertical cliffs break down, the minor details of the profiles 

 are often altered. This is a natural result of the mode in which 

 these beds were formed. They are fluviatile and estuarine. The 

 river has eroded and shifted, banks and shoals have been formed, 

 .and such occurrences have produced many irregularities in the 

 strata. 



After a renewed examination of the descriptions given by 

 F »be8, in his masterly work on the Oligocene beds of Wight, I 

 fi ave, however, found that in these beds, too, the number of 



